Note: Descriptions are shown in the official language in which they were submitted.
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Pasteurization plant and method for operating a pasteurizing plant.
The invention relates to a plant for the pasteurization of foodstuff and
method for operating
such pasteurizing plant.
The pasteurization of foodstuff nowadays is commonly used to minimize the
amount of mi-
croorganism in the foodstuff. Amongst other things, the shelf life of the
foodstuff can be pro-
longed in this way, and possible health problems arising from harmful bacteria
or from
spoiled food caused by microorganisms for example, can be impeded.
A widely-used method for pasteurizing foodstuff comprises filling the
foodstuff into contain-
ers, closing the containers and then applying a temperature-controlled process
liquid onto the
containers. Frequently, so-called tunnel pasteurizers are used for such
purpose, wherein the
containers filled with the foodstuff are transported through several
temperature treatment
zones. Such tunnel pasteurizers are for example commonly used to pasteurize
beverages filled
into bottles or cans.
In tunnel pasteurizers, the containers filled with the foodstuff usually are
first treated in one or
more heating zones with process liquid having a moderate temperature level, to
allow for gen-
tie heating up of the foodstuff. To this end the containers may successively
be treated in sev-
eral heating zones with process liquid having rising temperature levels.
Hereafter, process
liquid having a temperature level high enough to kill microorganisms is
applied onto the con-
tainers filled with the foodstuff in one or more pasteurizing zones.
Subsequently the contain-
ers have to be cooled down in one or several cooling zones in most cases, in
order to prevent
deterioration of the foodstuff within the containers.
For such pasteurization processes, process liquid having low temperature
level, as well as
process liquid having high temperature level have to be provided. It is known
in the art, to use
recuperation of process liquid for the heating or cooling in the treatment
zones. It is also
known in the art, to use a heat pump for transferring thermal energy from
process liquid hav-
ing low temperature level to process liquid having high temperature level.
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DE 10 2013 112 398 Al for example discloses a tunnel pasteurizer, wherein for
recuperation
process liquid after having passed heating zones is transferred to cooling
zones and vice versa.
In addition, the pasteurizing line in DE 10 2013 112 398 Al discloses a heat
pump, which is
used to transfer thermal energy from process liquid having low temperature
level to process
liquid having high temperature level within the pasteurizing line.
In principle, heat pumps are the most energy-efficient means for providing
thermal energy
within pasteurizing lines, which require both heating and cooling procedures.
However, pri-
marily due to the varying operation conditions of pasteurizing lines, as the
one disclosed in
DE 10 2013 112 398 Al, the energy efficiency of the heat pump cannot be
exploited to the
best possible extend, and further need exists for optimizing the energy
management of pas-
teurizing plants.
The objective of the invention is to meet this need, and to provide an
improved pasteurizing
plant and an improved method for operating a pasteurizing plant, in order to
enhanced the
energy efficiency of the pasteurizing plant.
This objective is achieved by a method and a pasteurizing plant as defined in
the claims.
A method for operating a pasteurizing plant is provided. The pasteurizing
plant comprises a
first pasteurizing line and at least a second pasteurizing line. In each of
the first and second
pasteurization lines sealed containers filled with foodstuff are conveyed
through at least one
heating zone and subsequently through at least one cooling zone. In each of
the first and sec-
ond pasteurization lines, the foodstuff is heated in the at least one
respective heating zone by
dispensing a temperature-controlled process liquid onto the containers, and in
each of the first
and second pasteurizing lines the foodstuff subsequently is cooled in the at
least one respec-
tive cooling zone by dispensing a temperature-controlled process liquid onto
the containers.
Furthermore, a heating liquid is heated by means of a heating means of a heat
pump and a
cooling liquid is cooled by means of a cooling means of the heat pump.
Based on heating demand for the first and second pasteurizing lines, the
heated heating liquid
from the heating means of the heat pump is used to heat process liquid with a
high tempera-
ture level of the first pasteurizing line by means of a first heating heat
exchanger, and/or the
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heated heating liquid from the heating means of the heat pump is used to heat
process liquid
with a high temperature level of the second pasteurizing line by means of a
second heating
heat exchanger. In addition, based on cooling demand for the first and second
pasteurizing
lines, the cooled cooling liquid from the cooling means of the heat pump is
used to cool pro-
cess liquid with a low temperature level of the first pasteurizing line by
means of a first cool-
ing heat exchanger, and/or the cooled cooling liquid from the cooling means of
the heat pump
is used to cool process liquid with a low temperature level of the second
pasteurizing line by
means of a second cooling heat exchanger.
For heating the process liquid with a high temperature level of the first
and/or the second pas-
teurizing line, the heated heating liquid from the heating means of the heat
pump is conveyed
through a primary side of the first and/or the second heating heat exchanger,
while the process
liquid of the first and/or the second pasteurizing line is conveyed through a
secondary side of
the first and/or the second heating heat exchanger. For cooling the process
liquid with a low
temperature level of the first and/or the second pasteurizing line, the cooled
cooling liquid
from the cooling means of the heat pump is conveyed through a primary side of
the first
and/or the second cooling heat exchanger, while the process liquid of the
first and/or the sec-
ond pasteurizing line is conveyed through a secondary side of the first and/or
the second cool-
ing heat exchanger. The heating liquid is heated by conveying the heating
liquid through the
heating means of the operated heat pump, and the cooling liquid is cooled by
conveying the
heating liquid through the cooling means of the operated heat pump.
By way of the method, the energy efficiency of the pasteurizing plant can be
significantly
enhanced, as the heated heating liquid and the cooled cooling liquid can be
used according to
the heating and cooling demands of the first and the at least second
pasteurizing lines respec-
tively. Such varying heating and cooling demands may for example result from
different pas-
teurizing temperatures or different target cooling temperatures being required
for individual
foodstuffs. Vast differences in heating and cooling demands also result upon
starting up a
pasteurizing line, or when finishing the pasteurization of a charge, for
example for a batch
change or for maintenance. Upon starting up, a pasteurizing line has a lot of
heating demand
and low or no cooling demand, as initially a lot of containers must be heated
up, while no or
only a few containers must be cooled done. Upon completing a cycle of a
pasteurizing line
and shutting done a pasteurizing line, a lot of cooling demand will result
while the heating
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demand drops, as at the end of a cycle, a lot of containers must finally be
cooled down, while
no new containers to be heated are inserted into the pasteurizing line.
Differences in demand
may for example also result from the initial temperatures of the containers
being inserted into
a pasteurizing line. The actual heating and cooling demands of the
pasteurizing lines can for
example be determined by placing temperature sensors at suitable positions, to
measure and
monitor the temperatures of the process liquids in the first and second
pasteurizing lines.
The heated heating liquid may be used to heat the process liquid in a
pasteurizing line having
high heating demand. On the other hand, the cooled cooling liquid may be used
to cool pro-
cess liquid in a pasteurizing line having high cooling demand. Thus, by using
the method,
thermal energy can efficiently even be transferred between pasteurizing lines,
for example by
cooling process fluid of a pasteurizing line with high actual cooling demand,
and transferring
the excess thermal energy to a pasteurizing line with high heating demand, by
heating the
process liquid of this pasteurizing line. Such transferring of thermal energy
between pasteuriz-
ing lines can thus be achieved without mixing the process liquids of the
pasteurizing lines.
Finally, the method enables a continuous, energy-efficient operation of the
heat pump at a
high-performance level, as both the heating and cooling capacity of the heat
pump can be ex-
ploited to a very high extend. This allows for operation of the heat pump in a
region of a very
high coefficient of performance (COP) for heating and cooling. A person
skilled in the art will
appreciate, that the method can of course be extended to operating more than
two pasteurizing
lines, for example by heating and/or cooling process liquid of a third
pasteurizing line, a
fourth pasteurizing line and so on. Operation of additional pasteurizing lines
may be included
with method in the same way as operation of the first and the second
pasteurizing lines.
An embodiment of the method may comprise, that based on heating demand for the
first and
second pasteurizing lines, the heated heating liquid from the heating means of
the heat pump
is fed into an upper region of a heating liquid buffer tank, and heating
liquid is fed back into
the heating means of the heat pump from a lower region of the heating liquid
buffer tank.
By way of these measures, the energy efficiency of operation of the
pasteurizing plant can be
further enhanced. In case of low or no heating demand in the pasteurizing
lines for example,
the heated heating liquid can be used to rise the overall temperature level in
the heating liquid
CA 2996922 2018-02-28
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buffer tank. Therefore, any excess thermal energy generated by heat pump is
not wasted, but
can temporarily be stored in the heating liquid buffer tank for later use. The
heating liquid
buffer tank may preferably be operated as layered storage tank, with
temperature sensors be-
ing used to monitor the temperature levels of the heating liquid at various
heights within the
heating liquid buffer tank.
A further embodiment may then for example comprise, that based on heating
demand for the
first and second pasteurizing lines, heating liquid is fed into the first
heating heat exchanger
and/or the second heat exchanger from the upper region of the heating liquid
buffer tank in
order to heat the process liquid with a high temperature level of the first
pasteurizing line
and/or the second pasteurizing line, and heating liquid from the first heat
exchanger and/or
from the second heat exchanger is fed back into the lower region of the
heating liquid buffer
tank.
Such procedure is of particular advantage, when high heating demand exists in
the first and/or
second pasteurizing lines. In this way, the heating capacity of the heat pump
can be exploited
to a higher extend, and the use of additional heating means with lower energy
efficiency can
at least be restricted during operation of the pasteurizing plant.
Preferably, the heated heating liquid from the heating means is fed into the
heating liquid
buffer tank via a hollow profile body with openings within a section of its
circumferential
surface, the hollow profile body being arranged within the upper region of the
heating liquid
buffer tank such that all openings face towards an upper end of the heating
liquid buffer tank,
and that heating liquid from the heating liquid buffer tank is fed back into
the heating means
via a further hollow profile body with openings within a section of its
circumferential surface,
the further hollow profile body being arranged within the lower region of the
heating liquid
buffer tank such that all openings face towards a lower end of the heating
liquid buffer tank.
Through these measures, the heating liquid buffer tank may be operated as
layered storage
tank in a very efficient way. The heating liquid heated by the heating means
of the heat pump
has a comparatively high temperature level. Upon loading, this heated heating
liquid with
high temperature level can be guided or pushed towards the upper end of the
heating liquid
buffer tank by means of the hollow profile body arranged in the upper region,
thus displacing
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layers of heating liquid with moderate temperature level towards lower regions
of the heating
liquid buffer tank. Heating liquid with a comparatively low temperature level
strati-
fied/layered in the lower regions of the heating liquid buffer tank, can on
the other hand be
conveyed to the heating means of the heat pump via the further hollow profile
body. In this
way, an undesirable mixing of the heating liquid layers with different
temperature levels in
the heating liquid buffer tank, and thus an undesired levelling out of
temperatures can be im-
peded. In the following, this allows for operation of the heat pump at best
possible COP for
heating, as stable temperature levels of the heating liquid in the upper and
lower regions of the
heating liquid buffer tank can be provided for a long time while loading the
heating liquid
buffer tank with thermal energy.
Furthermore, it may be convenient, that based on heating demand for the first
and second pas-
teurizing lines and based on temperatures of the heating liquid in the heating
liquid buffer
tank, the heating liquid from the upper region of the heating liquid buffer
tank is fed into the
first heating heat exchanger and/or the second heating heat exchanger via the
hollow profile
body, and heating liquid from the first and/or second heating heat exchanger
is fed back into
the lower region of the heating liquid buffer tank via the further hollow
profile body.
In this manner, the heating liquid buffer tank can also be efficiently
operated as layered buffer
tank upon unloading. With such layered liquid buffer tank a stable long-term
operation of the
heat pump at high COP is enabled.
Independently, an embodiment of the method may comprise that, based on cooling
demand
for the first and second pasteurizing lines, cooled cooling liquid from the
cooling means of the
heat pump is fed into a lower region of a cooling liquid buffer tank, and
cooling liquid is fed
back into the cooling means of the heat pump from an upper region of the
cooling liquid buff-
er tank.
The cooled cooling liquid can be used to lower the overall temperature level
in the cooling
liquid buffer tank in this way, and the cooling capacity of the heat pump can
be used fully
even if low or no cooling demand exists in any of the pasteurizing lines. The
cooling liquid
buffer tank may also preferably be operated as layered storage tank, with
temperature sensors
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being used to monitor the temperature levels of the cooling liquid at various
heights within
the cooling liquid buffer tank.
A further embodiment may comprise, that based on cooling demand for the first
and second
pasteurizing lines, cooling liquid is fed into the first cooling heat
exchanger and/or the second
cooling heat exchanger from the lower region of the cooling liquid buffer tank
in order to cool
the process liquid with a low temperature level of the first pasteurizing line
and/or the second
pasteurizing line, and cooling liquid from the first cooling heat exchanger
and/or from the
second cooling heat exchanger is fed back into the upper region of the cooling
liquid buffer
tank.
Such procedure is of particular advantage, when a high cooling demand exists
in the first
and/or second pasteurizing lines. By way of these measures, also the cooling
capacity of the
heat pump can be exploited to a higher extend, and the use of additional
cooling means with
lower energy efficiency can at least be restricted during operation of the
pasteurizing plant.
Preferably, the cooled cooling liquid from the cooling means of the heat pump
is fed into the
cooling liquid buffer tank via a hollow profile body with openings within a
section of its cir-
cumferential surface, the hollow profile body being arranged within the lower
region of the
heating liquid buffer tank such that all openings face towards a lower end of
the cooling liquid
buffer tank, and that cooling liquid from the cooling liquid buffer tank is
fed back into the
cooling means via a further hollow profile body with openings within a section
of its circum-
ferential surface, the further hollow profile body being arranged within the
upper region of the
cooling liquid buffer tank such that all openings face towards an upper end of
the cooling liq-
uid buffer tank.
In this way, also the cooling buffer tank may be operated as layered storage
tank in a very
efficient way, as the cooling liquid from the cooling means, having a
comparatively low tem-
perature level, can be guided or pushed to the lower end of the cooling liquid
buffer tank by
means of the hollow profile body arranged in the lower region of the cooling
buffer tank. Up-
on loading, this cooling liquid with low temperature level displaces layers of
cooling liquid
with moderate temperature level towards higher regions of the cooling liquid
buffer tank. On
the other hand, cooling liquid with a comparatively high temperature level
stratified/layered in
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the upper regions of the cooling liquid buffer tank can be conveyed to the
cooling means of
the heat pump via the further hollow profile body. In this way, an undesirable
mixing of the
cooling liquid layers with different temperature levels in the cooling liquid
buffer tank, and
thus an undesired levelling out of temperatures can be impeded. In the
following, this allows
for operation of the heat pump at best possible COP for cooling, as stable
temperature levels
of the cooling liquid in the lower and upper regions of the cooling liquid
buffer tank can be
provided for a long time while loading the cooling liquid buffer tank.
Furthermore, it may be advantageous, that based on cooling demand for the
first and second
pasteurizing lines and based on temperatures of the cooling liquid in the
cooling liquid buffer
tank, the cooling liquid from the lower region of the cooling liquid buffer
tank is fed into the
first cooling heat exchanger and/or the second cooling heat exchanger via the
hollow profile
body, and cooling liquid from the first and/or second cooling heat exchanger
is fed back into
the upper region of the cooling liquid buffer tank via the further hollow
profile body.
In this manner, the cooling liquid buffer tank can also be efficiently
operated as layered buffer
tank upon unloading. With such layered liquid buffer tank a stable long-term
operation of the
heat pump at high COP is enabled.
Independently, another embodiment of the method may comprise, that based on
cooling de-
mand for the first and second pasteurizing lines, the process liquids with a
low temperature
level of the first and/or the second pasteurizing lines are cooled further by
means of at least
one additional cooling device.
Through this measure, eventual cooling demand peaks or the need for
exceptional low tem-
perature levels for the process liquid in any of the pasteurizing lines can be
covered by the at
least one additional cooling device, and a heat pump with suitable cooling
capacity may be
utilized.
In such case, it may be convenient, that the process liquid(s) with a low
temperature level are
cooled further by conveying them through a heat exchanger of at least one air-
cooled cooling
tower.
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Herewith, the process liquid(s) can be cooled further by means of an
additional cooling device
with high cooling capacity. By means of the heat exchanger, a
contamination/pollution of the
process liquid(s) during further cooling, as for example potentially caused by
direct contact
with cooling air, can efficiently be prevented.
In addition, an enhanced pasteurizing plant is also provided to achieve the
objective of the
present invention.
The pasteurizing plant comprises a first pasteurizing line and at least a
second pasteurizing
line. Each of the first and the second pasteurizing lines comprise at least
one heating zone and
at least one cooling zone, the heating zones and the cooling zones each
comprising irrigation
means configured for dispensing a temperature controlled process liquid into
the respective
zones. Each of the first and the second pasteurizing lines comprise a
transporting means con-
figured for transporting sealed containers filled with foodstuff through the
at least one respec-
tive heating zone and subsequently through the at least one respective cooling
zone. The pas-
teurizing plant further comprises a heat pump with a heating means for heating
a heating liq-
uid and a cooling means for cooling a cooling liquid.
The heating means of the heat pump at least is operatively connected with a
primary side of a
first heating heat exchanger via liquid transport lines and at least one shut-
off means arranged
between solely the heating means and the first heating heat exchanger, and the
heating means
is additionally operatively connected with a primary side of a second heating
heat exchanger
via liquid transport lines and at least one further shut-off means arranged
between solely the
heating means and the second heating heat exchanger. At least one heating
liquid conveying
means is arranged for circulating the heating liquid through the heating
means, and through
the primary side of the first heating heat exchanger and/or through the
primary side of the
second heating heat exchanger. A secondary side of the first heating heat
exchanger is con-
nected with an input line and an output line for process liquid of the first
pasteurizing line,
and a secondary side of the second heating heat exchanger is connected with an
input line and
an output line for process liquid of the second pasteurizing line.
In addition, the cooling means of the heat pump at least is operatively
connected with a prima-
ry side of a first cooling heat exchanger via liquid transport lines and at
least one shut-off
means arranged between solely the cooling means and the first cooling heat
exchanger, and
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the cooling means is additionally operatively connected with a primary side of
a second cool-
ing heat exchanger via liquid transport lines and at least one shut-off means
arranged between
solely the cooling means and the second cooling heat exchanger. At least one
cooling liquid
conveying means is arranged for circulating the cooling liquid through the
cooling means, and
through the primary side of the first cooling heat exchanger and/or through
the primary side of
the second cooling heat exchanger. A secondary side of the first cooling heat
exchanger is
connected with an input line and an output line for process liquid of the
first pasteurizing line,
and a secondary side of the second cooling heat exchanger is connected with an
input line and
an output line for process liquid of the second pasteurizing line.
Through this structural design of the pasteurization plant, in operation of
the plant the heating
liquid can be heated by way of the heating means of the heat pump. Further on,
the heated
heating liquid can then be used to heat process liquid with a high temperature
level of the first
pasteurizing line by means of the first heating heat exchanger, and/or the
heated heating liquid
from the heating means of the heat pump can be used to heat process liquid
with a high tem-
perature level of the second pasteurizing line by means of the second heating
heat exchanger,
based on actual heating demand of the pasteurizing lines. Additionally, the
cooling liquid can
be cooled down in the cooling means of the heat pump in operation of the
pasteurizing plant,
and can then be used to cool process liquid with a low temperature level of
the first pasteuriz-
ing line by means of the first cooling heat exchanger, and/or can be used to
cool process liq-
uid with a low temperature level of the second pasteurizing line by means of
the second cool-
ing heat exchanger, based on actual cooling demand of the pasteurizing lines.
This allows for enhanced energy efficiency during operation of the
pasteurizing plant, as the
heating capacity as well as the cooling capacity of the heat pump can be
exploited to a very
high extend. This allows for operation of the heat pump in a region of a very
high COP for
heating and cooling. For determination of the actual heating and cooling
demands of the pas-
teurizing lines during operation, temperature sensors can be arranged at
suitable positions in
the pasteurizing lines. A person skilled in the art will appreciate, that the
pasteurizing plant
may of course comprise more than two pasteurizing lines. For example, a third
pasteurizing
line, a fourth pasteurizing line and so on, may be linked to the heat pump by
third and fourth
heating and cooling heat exchangers, in the same way as the first and the
second pasteurizing
lines.
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An embodiment of the pasteurizing plant may comprise, that an output of the
heating means is
connected with an upper region of a heating liquid buffer tank via liquid
transport lines and at
least one shut-off means arranged between solely the output of the heating
means and the up-
per region of the heating liquid buffer tank, and an input of the heating
means is connected
with a lower region of the heating liquid buffer tank via liquid transport
lines and at least one
shut-off means arranged between solely the input of the heating means and the
lower region
of the heating liquid buffer tank, and that separately at other positions of
the heating liquid
buffer tank an upper region and a lower region of the heating liquid buffer
tank are operative-
ly connected with the primary side of the first heating heat exchanger via
liquid transport lines
and at least one further shut-off means arranged between solely the heating
liquid buffer tank
and the first heating heat exchanger, and the upper region and the lower
region of the heating
liquid buffer tank are also operatively connected with the primary side of the
second heating
heat exchanger via liquid transport lines and at least one further shut-off
means arranged be-
tween solely the heating liquid buffer tank the second heating heat exchanger,
wherein at least
one further heating liquid conveying means is arranged for conveying the
heating liquid from
the upper region of the heating liquid buffer tank through the primary side of
the first heating
heat exchanger and/or through the primary side of the second heating heat
exchanger, and
back into the lower region of the heating liquid buffer tank from the first
heating heat ex-
changer and/or the from the second heating heat exchanger.
During operation of the pasteurizing plant and dependent on actual heating
demand for the
pasteurizing lines, heated heating liquid from the heating means of the heat
pump can be fed
into an upper region of a heating liquid buffer tank, and heating liquid can
be fed back into the
heating means of the heat pump from a lower region of the heating liquid
buffer tank. The
heating liquid buffer tank therefore particularly helps in case of low or no
heating demand in
the pasteurizing lines, as in this way excess thermal energy generated in the
heating means of
the heat pump can temporarily be stored in the heating liquid buffer tank for
later use. The
heating liquid buffer tank may preferably be configured as layered storage
tank, with tempera-
ture sensors arranged at various heights within the heating liquid buffer
tank. Based on heat-
ing demand for the first and second pasteurizing lines during operation of the
pasteurizing
plant, heating liquid can then be fed into the first heating heat exchanger
and/or the second
heat exchanger from the upper region of the heating liquid buffer tank, and
the heating liquid
CA 2996922 2018-02-28
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from the first heat exchanger and/or from the second heat exchanger can be fed
back into the
lower region of the heating liquid buffer tank during operation. By way of
using the heating
liquid buffer tank in such manner, the heating capacity of the heat pump can
be exploited to a
higher extend, and the use of additional heating means with lower energy
efficiency as com-
pared to the heat pump can at least be restricted during operation of the
pasteurizing plant.
Another embodiment may comprise, that the liquid transport lines leading from
the output of
the heating means to the upper region of the heating liquid buffer tank are
connected to a hol-
low profile body with openings within a section of its circumferential
surface, which hollow
profile body is arranged within the upper region of the heating liquid buffer
tank such that all
openings face towards an upper end of the heating liquid buffer tank, and that
the liquid
transport lines leading from the lower region of the heating liquid buffer
tank to the input of
the heating means are connected to a further hollow profile body with openings
within a sec-
tion of its circumferential surface, which further hollow profile body is
arranged within the
lower region of the heating liquid buffer tank such that all openings face
towards a lower end
of the heating liquid buffer tank.
By way of these constructive elements, the heating liquid buffer tank can be
operated as lay-
ered buffer tank during operation of the pasteurizing plant. Upon loading,
heated heating liq-
uid from the heating means can be fed into the heating liquid buffer tank via
the hollow pro-
file body arranged within the upper region. The hollow profile body can for
example be ar-
ranged approximately in the middle of the upper third of the heating liquid
buffer tank. The
hollow profile body thereby acts as guiding means and the heating liquid with
high tempera-
ture level from the heating means of the heat pump is pushed towards the upper
end of the
heating liquid buffer tank upon feeding. Thereby, layers of heating liquid
with moderate tem-
perature level are displaced towards lower regions of the heating liquid
buffer tank. Heating
liquid with comparatively low temperature level from the lower region of the
heating liquid
buffer tank can be fed back into the heating means via the further hollow
profile body ar-
ranged within the lower region of the heating liquid buffer tank during
operation of the pas-
teurizing plant. This further hollow profile body can for example be arranged
approximately
in the middle of the lower third of the heating liquid buffer tank. Through
the hollow profile
bodies, an undesirable mixing of heating liquid layers with different
temperature levels in the
heating liquid buffer tank can be impeded during operation of the pasteurizing
plant. In the
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following, this allows for operation of the heat pump at best possible COP for
heating, as sta-
ble temperature levels of the heating liquid in the upper and lower regions of
the heating liq-
uid buffer tank can be provided for a long time while loading the heating
liquid buffer tank
with thermal energy.
Furthermore, it may be advantageous, that the liquid transport lines leading
from the upper
region of the heating liquid buffer tank to the first heating heat exchanger
and the liquid
transport lines leading from the upper region of the heating liquid buffer
tank to the second
heating heat exchanger are connected to the hollow profile body arranged
within the upper
region of the heating liquid buffer tank, and that the liquid transport lines
leading from the
first heating heat exchanger and the liquid transport lines leading from the
second heating heat
exchanger to the lower region of the heating liquid buffer tank are connected
to the hollow
profile body arranged within the lower region of the heating liquid buffer
tank.
During operation of the pasteurizing plant and based on heating demand for the
first and sec-
ond pasteurizing lines, and based on temperatures of the heating liquid in the
heating liquid
buffer tank, the heating liquid from the upper region of the heating liquid
buffer tank can be
fed into the first heating heat exchanger and/or the second heating heat
exchanger via the hol-
low profile body, and heating liquid from the first and/or second heating heat
exchanger can
be fed back into the lower region of the heating liquid buffer tank via the
further hollow pro-
file body. This also enables efficient operation of the heating liquid buffer
tank as layered
buffer tank upon unloading.
Independently, an embodiment of the pasteurizing plant may comprise, that an
output of the
cooling means is connected with lower region of a cooling liquid buffer tank
via liquid
transport lines and at least one shut-off means arranged between solely the
output of the cool-
ing means and the lower region of the cooling liquid buffer tank, and an input
of the cooling
means is connected with an upper region of the cooling liquid buffer tank via
liquid transport
lines and at least one shut-off means arranged between solely the input of the
cooling means
and the upper region of the cooling liquid buffer tank, and that separately at
other positions of
the cooling liquid buffer tank a lower region and an upper region of the
cooling buffer tank
are operatively connected with the primary side of the first cooling heat
exchanger via liquid
transport lines and at least one further shut-off means arranged between
solely the cooling
CA 2996922 2018-02-28
- 14 -
liquid buffer tank and the first cooling heat exchanger, and the lower region
and the upper
region of the cooling buffer tank are also operatively connected with the
primary side of the
second cooling heat exchanger via liquid transport lines and at least one
further shut-off
means arranged between solely the cooling liquid buffer tank and the second
cooling heat
exchanger, wherein at least one further cooling liquid conveying means is
arranged for con-
veying the cooling liquid from the lower region of the cooling liquid buffer
tank through the
primary side of the first cooling heat exchanger and/or through the primary
side of the second
cooling heat exchanger, and back into the upper region of the cooling liquid
buffer tank.
Based or dependent on actual cooling demand for the pasteurizing lines during
operation of
the pasteurizing plant, cooled cooling liquid from the cooling means of the
heat pump can be
fed into a lower region of a cooling liquid buffer tank, and cooling liquid
can be fed back into
the cooling means of the heat pump from an upper region of the cooling liquid
buffer tank.
The cooling liquid buffer tank therefore may serve as temporary storage device
for cooled
cooling liquid with low temperature level during operation, and the cooling
capacity of the
heat pump can be used fully even if low or no cooling demand exists in any of
the pasteuriz-
ing lines. The cooling liquid buffer tank may preferably be configured as
layered storage tank,
with temperature sensors arranged at various heights within the heating liquid
buffer tank. In
dependence of cooling demand for the first and second pasteurizing lines
during operation,
cooling liquid can then be fed into the first cooling heat exchanger and/or
the second cooling
heat exchanger from the lower region of the cooling liquid buffer tank in
order to cool the
process liquid with a low temperature level of the first pasteurizing line
and/or the second
pasteurizing line, and cooling liquid from the first cooling heat exchanger
and/or from the
second cooling heat exchanger can be fed back into the upper region of the
cooling liquid
buffer tank. By way of using the cooling liquid buffer tank in such manner,
the cooling capac-
ity of the heat pump can be exploited to a higher extend, and the use of
additional cooling
means with lower energy efficiency as compared to the heat pump can at least
be restricted
during operation of the pasteurizing plant.
Another embodiment of the pasteurizing plant may comprise, that the liquid
transport lines
leading from the output of the cooling means to the lower region of the
cooling liquid buffer
tank are connected to a hollow profile body with openings within a section of
its circumferen-
tial surface, which hollow profile body is arranged within the lower region of
the cooling liq-
CA 2996922 2018-02-28
=
- 15 -
uid buffer tank such that all openings face towards a lower end of the cooling
liquid buffer
tank, and that the liquid transport lines leading from the upper region of the
cooling liquid
buffer tank to the input of the cooling means are connected to a further
hollow profile body
with openings within a section of its circumferential surface, which further
hollow profile
body is arranged within the upper region of the cooling liquid buffer tank
such that all open-
ings face towards an upper end of the cooling liquid buffer tank.
Through using these constructive elements, the cooling liquid buffer tank can
also be operated
as layered buffer tank during operation of the pasteurizing plant. Upon
loading, cooled cool-
ing liquid from the cooling means of the heat pump can be fed into the cooling
liquid buffer
tank via the hollow profile body arranged within the lower region. The hollow
profile body
can for example be arranged approximately in the middle of the lower third of
the cooling
liquid buffer tank. The hollow profile body thereby acts as guiding means and
the cooling
liquid with low temperature level from the cooling means is pushed towards the
lower end of
the cooling liquid buffer tank upon feeding. Thereby, layers of cooling liquid
with moderate
temperature level are displaced towards upper regions of the cooling liquid
buffer tank. Cool-
ing liquid with comparatively high temperature level from the upper region of
the cooling
liquid buffer tank can be fed back into the cooling means via the further
hollow profile body
arranged within the upper region of the cooling liquid buffer tank during
operation of the pas-
teurizing plant. This further hollow profile body can for example be arranged
approximately
in the middle of the upper third of the cooling liquid buffer tank. Through
the hollow profile
bodies, an undesirable mixing of cooling liquid layers with different
temperature levels in the
cooling liquid buffer tank can be impeded during operation of the pasteurizing
plant. In the
following, this allows for operation of the heat pump at best possible COP for
cooling, as sta-
ble temperature levels of the cooling liquid in the lower and upper regions of
the cooling liq-
uid buffer tank can be provided for a long time while loading the cooling
liquid buffer tank.
Furthermore, it may be convenient, when the liquid transport lines leading
from the lower
region of the cooling liquid buffer tank to the first cooling heat exchanger
and the liquid
transport lines leading from the lower region of the cooling liquid buffer
tank to the second
cooling heat exchanger are connected to the hollow profile body arranged
within the lower
region of the cooling liquid buffer tank, and that the liquid transport lines
leading from the
first cooling heat exchanger and the liquid transport lines leading from the
second cooling
CA 2996922 2018-02-28
,
,
- 16 -
heat exchanger to the upper region of the cooling liquid buffer tank are
connected to the hol-
low profile body arranged within the upper region of the cooling liquid buffer
tank.
Based on cooling demand for the first and second pasteurizing lines, and based
on tempera-
tures of the cooling liquid in the cooling liquid buffer tank, the cooling
liquid from the lower
region of the cooling liquid buffer tank can then be fed into the first
cooling heat exchanger
and/or the second cooling heat exchanger via the hollow profile body, and
cooling liquid from
the first and/or second cooling heat exchanger can be fed back into the upper
region of the
cooling liquid buffer tank via the further hollow profile body. This also
enables efficient oper-
ation of the cooling liquid buffer tank as layered buffer tank upon unloading.
Independently, an embodiment of the pasteurizing plant may comprise at least
one additional
cooling device for further cooling the process liquids with a low temperature
level of the first
and/or the second pasteurizing lines.
During operation of the pasteurizing plant and based on cooling demand for the
first and sec-
ond pasteurizing lines during operation, the at least one additional cooling
device can be used
to further cool the process liquids with a low temperature level of the first
and/or the second
pasteurizing lines, thereby covering cooling demand peaks or the need for
exceptional low
temperature levels for the process liquid in any of the pasteurizing lines.
In such case the at least one additional cooling device may be an air-cooled
cooling tower
with a heat exchanger for conveying through the process liquid(s).
During operation of the pasteurizing plant, the process liquid(s) can then be
cooled further by
means of an additional cooling device with high cooling capacity. By means of
the heat ex-
changer, a contamination/pollution of the process liquid(s) caused by the
cooling air can ef-
fectively be prevented during operation.
To provide a better understanding, the invention is described in more detail
in the following
with reference to the appended figures.
These are highly simplified, schematic drawings illustrating the following:
CA 2996922 2018-02-28
- 17 -
Fig. 1 an embodiment of a pasteurizing plant;
Fig. 2 another embodiment of a pasteurizing plant.
Introductory, it should be pointed out, that the same parts described in the
different embodi-
ments are denoted by the same reference numbers and the same component names
and the
disclosures made throughout the description can be transposed in terms of
meaning to same
parts bearing the same reference numbers or same component names. Furthermore,
the posi-
tions chosen for the purposes of the description, such as top, bottom, side,
etc., relate to the
drawing specifically being described and can be transposed in terms of meaning
to a new po-
sition when another position is being described.
Fig.1 schematically shows an embodiment of a pasteurizing plant 1, with a
first pasteurizing
line 2 and a second pasteurizing line 3. In the exemplary embodiment shown in
Fig. 1, the
first and second pasteurizing lines 2, 3 are configured as so-called tunnel
pasteurizers. Each of
the pasteurizing lines 2, 3 comprises a transporting means 5, for example a
conveyor belt or
other transporting device, configured for transporting containers 4. In a
transporting direction
6 for the containers 4, each of the first and second pasteurizing lines 2, 3
may comprise heat-
ing zones 7, 8 for successively heating up the containers and the foodstuff,
further heating
zones 9, 10 for further heating up and pasteurizing the foodstuff, and cooling
zones 11, 12 for
successively cooling down the containers 4 and the foodstuff In operation of
each of the first
and second pasteurization lines 2, 3, sealed containers 4 filled with
foodstuff, for example
beverages, can then be conveyed through the heating and pasteurizing zones 7,
8, 9, 10 and
subsequently through the cooling zones 11, 12.
The first and second pasteurizing lines 2, 3 schematically shown in Fig. 1
comprise identical
elements. Depending on need or purpose, it is of course possible for a
pasteurizing line to
comprise more or fewer zones as compared to the exemplary embodiment shown in
Fig. 1 for
example. A pasteurizing line 2, 3 hereby comprises at least one heating zone
7, 8, 9, 10 and at
least one cooling zone 11, 12, through which the containers are conveyed. It
is likewise possi-
ble for further treatment zones to be provided. For example, a zone for drying
the outer side of
the containers 4 could be provided subsequently for the cooling zone 12
arranged in the
transport direction 6 at the end. For reasons of clarity, such alternative
designs of pasteurizing
CA 2996922 2018-02-28
=
- 18 -
lines are not described. A person skilled in the art will appreciate, that the
present invention
can be executed with such alternative designs of pasteurizing lines.
During operation, the foodstuff can independently be heated in the respective
heating zones 7,
8, 9, 10 of each of the first and second pasteurizing lines 2, 3, by
dispensing a temperature-
controlled process liquid onto the respective containers 4 in each of the
respective heating
zones 7, 8, 9, 10. The foodstuff subsequently can independently be cooled in
the respective
cooling zones 11, 12 of each of the first and second pasteurizing lines 2, 3,
by dispensing a
temperature-controlled process liquid onto the respective containers 4 in each
of the respec-
tive cooling zones 11, 12. For this purpose, the temperature treatment zones
7, 8, 9, 10, 11,
12, may be equipped with irrigation means 13, for example sprinkler or shower
devices
known in the art, configured for dispensing a temperature-controlled process
liquid onto the
containers 6. In the embodiment shown in Fig. 1, temperature-controlled
process liquid can be
fed to the irrigations means 13 of the temperature treatment zones 7, 8, 9,
10, 11, 12 of each
of the first and second pasteurizing line 2, 3, by means of liquid conveying
devices 14, for
example circulation pumps.
After crossing the respective temperature treatment zones 7, 8, 9, 10, 11, 12,
the process liq-
uid may be collected at bottom areas 15 of the treatment zones 7, 8, 9, 10,
11, 12, and may
preferably be reused within the respective pasteurizing lines 2, 3. Portions
of process liquid
from the bottom areas 15 may be conveyed to other temperature treatment zones
7, 8, 9, 10,
11, 12 via recuperation lines 16. In each of the pasteurizing lines 2, 3, a
portion of the process
liquid from the bottom area of the last cooling zone 12 may for example be
transferred to the
first heating zone 7, and vice versa. Such recuperation of process liquid is
particular meaning-
ful, as the temperature of the process liquid falls upon heating up the
containers 4 in the heat-
ing zones 7, and rises upon cooling down the containers 4 in the cooling zones
12. Therefore,
direct reuse of those process liquids for heating and cooling of the
containers 4 is expedient, at
least with the exemplary pasteurizing lines 2, 3 shown in Fig. 1.
Portions of process liquid with comparatively high temperature level collected
at the bottom
areas 15, may be transferred to respective hot collection tanks 17 of the
pasteurizing lines 2, 3
for example. Portions of process liquid with comparatively low temperature
level collected at
the bottom areas 15, may be transferred to respective cold collection tanks
18. The process
CA 2996922 2018-02-28
- 19 -
liquids in the hot and cold collection tanks 17, 18 may be used to set or
adjust respective tem-
peratures for process liquid to be fed into the individual temperature
treatment zones 7, 8, 9,
10, 11, 12. For this purpose, each of the conveying devices 14 on the input
side may be con-
nected with the hot and cold collection tanks 17, 18 via metering devices 19,
as shown in the
embodiment according to Fig. 1. In this way, process liquid from the
respective hot and cold
collection tanks 17, 18 may be used for or added to a process liquid flow to
be fed into one of
the individual, respective temperature treatment zones 7, 8, 9, 10, 11, 12 of
the pasteurizing
lines 2, 3, in a controlled manner.
In order to enable gentle pre-heating of the foodstuff in the containers 4,
process liquid with a
temperature of approximately 35 C may for example be fed into heating zones 7
of the first
and second pasteurizing lines 2, 3. For further heating up the foodstuff,
process liquid with a
temperature of approximately 55 C may for example be fed into heating zones
8. For further
heating up and effective pasteurization of the foodstuff in the containers 4,
process liquid with
a temperature of approximately 85 C or higher may for example be fed into the
respective
heating zones 9, 10. For the purpose of cooling down the foodstuff in the
containers in a con-
trolled manner, process liquid with a temperature level of approximately 50 C
may be fed
into cooling zones 11, and process liquid with an approximate temperature of
30 C may be
fed into the respective cooling zones 12 of the pasteurizing lines 2, 3. The
required tempera-
ture levels for the individual, respective temperature treatment zones 7, 8,
9, 10, 11, 12, may
however vary widely, for example in dependence of the foodstuff to be
pasteurized. Certain
foodstuff may require particular high pasteurizing temperatures, while
foodstuff comprising
temperature sensitive ingredients may require cooling down to particular low
temperature
levels after pasteurization for example.
By using recuperation of process liquid, and by using the metering devices 19,
the tempera-
ture of individual process liquid flows can be set and/or adjusted for the
respective, individual
temperature treatment zones 7, 8, 9, 10, 11, 12. Due to the mixing of process
liquid flows and
internal transfer of thermal energy, as well as exchange of thermal energy
with the environ-
ment however, heating and cooling means are still required to bring partial
quantities and/or
flows of the process liquids in the first and second pasteurizing lines 2, 3
to temperature lev-
els, which are suited for effective heating and cooling of the foodstuff in
the respective con-
tainers 4.
CA 2996922 2018-02-28
- 20 -
For this purpose, the pasteurizing plant 1 comprises a heat pump 20 with a
heating means 21
for heating a heating liquid and a cooling means 22 for cooling a cooling
liquid. The heat
pump 20 may for example be a conventional mechanical heat pump, driven by a
compressor.
In such case, the heating means 21 may be a condenser of the heat pump 20, and
the cooling
means 22 may be an evaporator of the heat pump 20. As is known in the art,
such heat pump
20 may be used to extract thermal energy from the cooling liquid in the
cooling means 22, and
may be used to supply thermal energy to the heating liquid in the heating
means 21.
As shown in Fig. 1, the heating means 21 of the heat pump 20 at least is
operatively connect-
ed with a primary side of a first heating heat exchanger 23 via liquid
transport lines 24 and at
least one shut-off means 25 arranged between solely the heating means 21 and
the first heat-
ing heat exchanger 23. The first heating heat exchanger 23 is assigned to the
first pasteurizing
line 2. The heating means 21 is additionally operatively connected with a
primary side of a
second heating heat exchanger 26 via liquid transport lines 24 and at least
one shut-off means
arranged between solely the heating means 21 and the second heating heat
exchanger 26.
The second heating heat exchanger 26 is assigned to the second pasteurizing
line 3. At least
one heating liquid conveying means 27 is arranged for circulating the heating
liquid through
the heating means 21, and through the primary side of the first heating heat
exchanger 23
20 and/or through the primary side of the second heating heat exchanger 26.
A secondary side of
the first heating heat exchanger 23 is connected with an input line 28 and an
output line 29 for
process liquid of the first pasteurizing line 2, and a secondary side of the
second heating heat
exchanger 26 is connected with an input line 30 and an output line 31 for
process liquid of the
second pasteurizing line 3.
25 In addition, the cooling means 22 of the heat pump 20 at least is
operatively connected with a
primary side of a first cooling heat exchanger 32 via liquid transport lines
24 and at least one
shut-off means 25 arranged between solely the cooling means 22 and the first
cooling heat
exchanger 32. The first cooling heat exchanger 32 is assigned to the first
pasteurizing line 2.
The cooling means 22 is additionally operatively connected with a primary side
of a second
cooling heat exchanger 33 via liquid transport lines 24 and at least one shut-
off means 25 ar-
ranged between solely the cooling means 22 and the second cooling heat
exchanger 33. The
second cooling heat exchanger 33 is assigned to the second pasteurizing line
3. At least one
cooling liquid conveying means 34 is arranged for circulating the cooling
liquid through the
CA 2996922 2018-02-28
- 21 -
cooling means 22, and through the primary side of the first cooling heat
exchanger 32 and/or
through the primary side of the second cooling heat exchanger 33. A secondary
side of the
first cooling heat exchanger 32 is connected with an input line 35 and an
output line 36 for
process liquid of the first pasteurizing line 2, and a secondary side of the
second cooling heat
exchanger 33 is connected with an input line 37 and an output line 38 for
process liquid of the
second pasteurizing line 3.
Some further embodiments of the invention are depicted in Fig.2, and are
described with ref-
erence to Fig. 2 in the following. Fig. 2 shows parts of a pasteurizing plant
1 comprising a
first pasteurizing line 2 and a second pasteurizing line 3, as also shown in
the embodiment
depicted in Fig. 1. For improving clarity however, the first and second
pasteurizing lines 2, 3
are drawn in a very simplified manner in Fig. 2. For a possible design of such
pasteurizing
lines 2, 3, reference is made to Fig. 1 and the description referring to Fig.
1.
As depicted in Fig. 2, the pasteurizing plant 1 may further comprise a heating
liquid buffer
tank 39. An output 40 of the heating means 21 of the heat pump 20 may be
connected with an
upper region of the heating liquid buffer 39 tank via liquid transport lines
24 and at least one
shut-off means 25 arranged between solely the output 40 of the heating means
21 and the up-
per region of the heating liquid buffer 39 tank. An input 41 of the heating
means 21 may be
connected with a lower region of the heating liquid buffer tank 39 via liquid
transport lines 24
and at least one shut-off means 25 arranged between solely the input 41 of the
heating means
21 and the lower region of the heating liquid buffer tank 39.
Separately at other positions of the heating liquid buffer tank 39 an upper
region and a lower
region of the heating liquid buffer tank 39 may be operatively connected with
the primary side
of the first heating heat exchanger 23 via liquid transport lines 24 and at
least one further shut-
off means 25 arranged between solely the heating liquid buffer tank 39 and the
first heating
heat exchanger 23, and the upper region and a lower region of the heating
liquid buffer tank
39 may also be operatively connected with the primary side of the second
heating heat ex-
changer 26 via liquid transport lines 24 and at least one further shut-off
means 25 arranged
between solely the heating liquid buffer tank 39 and the second heating heat
exchanger 26. At
least one further heating liquid conveying means 42 may be arranged for
conveying the heat-
ing liquid from the upper region of the heating liquid buffer tank 39 through
the primary side
CA 2996922 2018-02-28
- 22 -
of the first heating heat exchanger 23 and/or through the primary side of the
second heating
heat exchanger 26, and back into the lower region of the heating liquid buffer
tank 39 from
the first heating heat exchanger 23 and/or the from the second heating heat
exchanger 26.
The heating liquid conveying means 27 arranged for conveying the heating
liquid through the
primary side of the first heating heat exchanger 23 and/or through the primary
side of the sec-
ond heating heat exchanger 26, may also be arranged for circulating the
heating liquid be-
tween the heating means 21 of the heat pump 20 and the heating liquid buffer
tank 39 as
shown in Fig. 2. Alternatively, a further conveying means may be arranged for
this purpose.
The heating liquid buffer tank 39 may preferably be configured as layered
storage tank, with
temperature sensors 53 arranged at various heights within the heating liquid
buffer tank for
temperature monitoring, as depicted in Fig. 2.
In a preferred embodiment, the liquid transport lines 24 leading from the
output 40 of the
heating means 21 of the heat pump 20 to the upper region of the heating liquid
buffer tank 39
may be connected to a hollow profile body 43 with openings within a section of
its circumfer-
ential surface. As depicted in Fig. 2, the hollow profile body 43 may be
arranged within the
upper region of the heating liquid buffer tank 39 such that all openings face
towards an upper
end of the heating liquid buffer tank 39. The liquid transport lines 24
leading from the lower
region of the heating liquid buffer tank 39 to the input 41 of the heating
means 21 may be
connected to a further hollow profile body 44 with openings within a section
of its circumfer-
ential surface. The further hollow profile body 44 may be arranged within the
lower region of
the heating liquid buffer tank 39 such that all openings face towards a lower
end of the heat-
ing liquid buffer tank 39. The hollow profile body 43 may for example be
arranged within the
upper third of the heating liquid buffer tank 39, and the further hollow
profile body 44 may be
arranged within the lower third of the heating liquid buffer tank 39.
As can be further seen from the embodiment shown in Fig. 2, the liquid
transport lines 24
leading from the upper region of the heating liquid buffer tank 39 to the
first heating heat ex-
changer 23 and the liquid transport lines 24 leading from the upper region of
the heating liq-
uid buffer tank 39 to the second heating heat exchanger 26 may also be
connected to the hol-
low profile body 43 arranged within the upper region of the heating liquid
buffer tank 39, at a
position separate from the position, where the liquid transport lines 24
leading from the output
CA 2996922 2018-02-28
- 23 -
40 of the heating means 21 to the upper region of the heating liquid buffer
tank 39 are con-
nected to the hollow profile body 43. The liquid transport lines 24 leading
from the first heat-
ing heat exchanger 23 and the liquid transport lines 24 leading from the
second heating heat
exchanger 26 to the lower region of the heating liquid buffer tank 39 may also
be connected to
the hollow profile body 44 arranged within the lower region of the heating
liquid buffer tank
39, at a position separate from the position, where the liquid transport lines
24 leading from
the lower region of the heating liquid buffer tank 39 to the input 41 of the
heating means 21
are connected to the hollow profile body 44.
The pasteurizing plant 1 may further comprise a cooling liquid buffer tank 45,
as shown for
the embodiment depicted in Fig. 2. An output 46 of the cooling means 22 may be
connected
with a lower region of a cooling liquid buffer tank 45 via liquid transport
lines 24 and at least
one shut-off means 25 arranged between solely the output 46 of the cooling
means 22 and the
lower region of the cooling liquid buffer tank 45. An input 47 of the cooling
means 22 may be
connected with an upper region of the cooling liquid buffer tank 45 via liquid
transport lines
24 and at least one shut-off means 25 arranged between solely the input 47 of
the cooling
means 22 and the upper region of the cooling liquid buffer tank 45.
Separately at other positions of the cooling liquid buffer tank 45, a lower
region and an upper
region of the cooling buffer tank 45 may be operatively connected with the
primary side of
the first cooling heat exchanger 32 via liquid transport lines 24 and at least
one further shut-
off means 25 arranged between solely the cooling liquid buffer tank 45 and the
first cooling
heat exchanger 32, and the lower region and the upper region of the cooling
buffer tank 45
may also be operatively connected with the primary side of the second cooling
heat exchanger
33 via liquid transport lines 24 and at least one further shut-off means 25
arranged between
solely the cooling liquid buffer tank 45 and the second cooling heat exchanger
33. At least
one further cooling liquid conveying means 48 may be arranged for conveying
the cooling
liquid from the lower region of the cooling liquid buffer tank 45 through the
primary side of
the first cooling heat exchanger 32 and/or through the primary side of the
second cooling heat
exchanger 33, and back into the upper region of the cooling liquid buffer tank
45.
The cooling liquid conveying means 34 arranged for conveying the heating
liquid through the
primary side of the first cooling heat exchanger 32 and/or through the primary
side of the sec-
CA 2996922 2018-02-28
- 24 -
ond cooling heat exchanger 33, may also be arranged for circulating the
cooling liquid be-
tween the cooling means 22 of the heat pump 20 and the cooling liquid buffer
tank 45 as
shown in Fig. 2. Alternatively, a further conveying means may be arranged for
this purpose.
Like the heating liquid buffer tank 39, the cooling liquid buffer tank 45 may
also be config-
ured as layered storage tank, with temperature sensors 53 arranged at various
heights within
the cooling liquid buffer tank 45 for temperature monitoring, as depicted in
Fig. 2.
Preferably, the liquid transport lines 24 leading from the output 46 of the
cooling means 22 to
the lower region of the cooling liquid buffer tank 45 may be connected to a
hollow profile
body 49 with openings within a section of its circumferential surface. The
hollow profile body
49 may be arranged within the lower region of the cooling liquid buffer tank
45 such that all
openings face towards a lower end of the cooling liquid buffer tank 45. The
liquid transport
lines 24 leading from the upper region of the cooling liquid buffer tank 45 to
the input 47 of
the cooling means 22 may be connected to a further hollow profile body 50 with
openings
within a section of its circumferential surface. The further hollow profile
body 50 may be ar-
ranged within the upper region of the cooling liquid buffer tank 45 such that
all openings face
towards an upper end of the cooling liquid buffer tank 45. The hollow profile
body 49 may for
example be arranged within the lower third of the cooling liquid buffer tank
45, and the fur-
ther hollow profile body 50 may be arranged within the upper third of the
cooling liquid buff-
er tank 45.
In addition, the liquid transport lines 24 leading from the lower region of
the cooling liquid
buffer tank 45 to the first cooling heat exchanger 32 and the liquid transport
lines 24 leading
from the lower region of the cooling liquid buffer tank 45 to the second
cooling heat exchang-
er 33 may also be connected to the hollow profile body 49 arranged within the
lower region of
the cooling liquid buffer tank 45, at a position separate from the position,
where the liquid
transport lines 24 leading from the output 46 of the cooling means 22 to the
lower region of
the cooling liquid buffer tank 45 are connected to the hollow profile body 49.
The liquid
transport lines 24 leading from the first cooling heat exchanger 32 and the
liquid transport
lines 24 leading from the second cooling heat exchanger 33 to the upper region
of the cooling
liquid buffer tank 45 may also be connected to the hollow profile body 50
arranged within the
upper region of the cooling liquid buffer tank 45, at a position separate from
the position,
CA 2996922 2018-02-28
- 25 -
where the liquid transport lines 24 leading from the upper region of the
cooling liquid buffer
tank 45 to the input 47 of the cooling means 22 are connected to the hollow
profile body 50.
As can be seen from Fig. 2, the heating means 21 of the heat pump, the first
heating heat ex-
changer 23, the second heating heat exchanger 26, and the heating liquid
buffer tank 39 are
elements of a heating circuit 51. During operation, the shut-off means 25
arranged between
distinct elements 21, 23, 26, 39 can be opened, to operatively connect
elements 21, 23, 26, 39
with one another. The cooling means 22 of the heat pump 20, the first cooling
heat exchanger
32, the second cooling heat exchanger 3 and the cooling liquid buffer tank 45
are elements of
a cooling circuit 52. As in the heating circuit 51, the shut-off means 25
arranged between dis-
tinct elements 22, 32, 33, 45 of the cooling circuit 52 can likewise be opened
during opera-
tion, to operatively connect distinct elements 22, 32, 33, 45 in the cooling
circuit 52 with one
another.
The shut-off means 25 arranged within the heating circuit 51 and the cooling
circuit 52 may
for example be open/close valves, or the like. In open position of such shut-
off means 25, dis-
tinct elements 21, 23, 26, 39 of the heating circuit 51 can be set in
operative flow connection
to each other respectively, such that heating liquid may be circulated between
elements in
flow connection, by driving the corresponding conveying means 27, 42 of the
heating circuit
51. Likewise, distinct elements 22, 32, 33, 45 of the cooling circuit 52 can
be set in operative
flow connection to each other, by opening the corresponding shut-off means 25.
By driving
the conveying means 34, 48 of the cooling circuit 52 cooling liquid may be
circulated be-
tween elements in flow connection. The shut-off means 25 may alternatively be
metering de-
vices, like flow control valves for example. By arranging such metering
devices, volumetric
flow rates of the heating liquid and the cooling liquid respectively,
circulated between ele-
ments 21, 23, 26, 39 in flow connection in the heating circuit 51 and elements
22, 32, 33, 45
in flow connection in the cooling circuit 52 respectively, can be controlled.
Alternatively, the shut-off means 25 may also be separate conveying means 27,
34, 42, 48 for
circulating the heating liquid and the cooling liquid respectively between
distinct elements 21,
23, 26, 39 of the heating circuit 51, and between distinct elements 22, 32,
33, 45 of the cool-
ing circuit 52. Such alternative embodiment is illustrated in Fig. 2 by way of
the elements
drawn in dashed lines. By means of the conveying means 27, 34, 42, 48 drawn in
dashed
CA 2996922 2018-02-28
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lines, distinct elements 21, 23, 26, 39 of the heating circuit 51 and distinct
elements 22, 32,
33, 45 of the cooling circuit 52 can be operatively connected or shut-off from
each other. In
case of such alternative embodiment, the shut-off means 25 and conveying means
27, 34, 42,
48 drawn in and designated with solid lines in Fig. 2, may of course be
omitted. Irrespective
of the number of conveying means being arranged in the heating circuit 51 and
the cooling
circuit 52, the conveying means 27, 34, 42, 48 preferably are flow control
devices, such as
pumps equipped with frequency converters.
During operation of the pasteurizing plant 1, the heating liquid may be heated
by means of the
heating means 21 of the heat pump 20, and the cooling liquid may be cooled by
means of the
cooling means 22 of the heat pump 20. With the embodiments of the pasteurizing
plant 1
shown in Fig. 1 and Fig. 2, and described above, the heated heating liquid and
the cooled
cooling liquid may advantageously be used for heating and cooling the process
liquids of the
first and second pasteurizing line 2, 3 with high flexibility, based on or
dependent on actual
heating demand and cooling demand within the first pasteurizing line 2 and the
second pas-
teurizing line 3.
Based on the heating demand for the first and second pasteurizing lines 2, 3,
the heated heat-
ing liquid from the heating means 21 of the heat pump 20 may be used to heat
process liquid
with a high temperature level of the first pasteurizing line 2 by means of a
first heating heat
exchanger 23. Additionally, or alternatively, the heated heating liquid from
the heating means
21 of the heat pump 20 may be used to heat process liquid with a high
temperature level of the
second pasteurizing line 3 by means of a second heating heat exchanger 26.
Based on cooling demand for the first and second pasteurizing lines 2, 3, the
cooled cooling
liquid from the cooling means 22 of the heat pump 20 may be used to cool
process liquid with
a low temperature level of the first pasteurizing line 2 by means of a first
cooling heat ex-
changer 32. Alternatively or additionally, the cooled cooling liquid from the
cooling means 22
of the heat pump 20 may be used to cool process liquid with a low temperature
level of the
second pasteurizing line 3 by means of a second cooling heat exchanger 33.
By way of this method, the energy efficiency of the pasteurizing plant 1 can
be significantly
enhanced, as the heated heating liquid and the cooled cooling liquid can be
used according to
CA 2996922 2018-02-28
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the heating and cooling demands of the first and the at least second
pasteurizing lines 2, 3
respectively. Thermal energy can even be transferred between the pasteurizing
lines 2, 3, for
example by cooling process fluid of a pasteurizing line 2, 3 with high actual
cooling demand,
and transferring the excess thermal energy to a pasteurizing line 2 ,3 with
high actual heating
demand, by heating its process liquid. Such transfer of thermal energy between
pasteurizing
lines 2, 3 can be achieved without mixing the process liquids of the
pasteurizing lines 2, 3.
For heating the process liquid with a high temperature level of the first
and/or the second pas-
teurizing line 2, 3, the heated heating liquid from the heating means 21 of
the heat pump 20 is
conveyed through the primary side of the first and/or the second heating heat
exchanger 23,
26, while the process liquid of the first and/or the second pasteurizing line
2, 3 is conveyed
through the secondary side of the first and/or the second heating heat
exchanger 23, 26. For
cooling the process liquid with a low temperature level of the first and/or
the second pasteur-
izing line 2, 3, the cooled cooling liquid from the cooling means 22 of the
heat pump 20 is
conveyed through the primary side of the first and/or the second cooling heat
exchanger 32,
33, while the process liquid of the first and/or the second pasteurizing line
2, 3 is conveyed
through the secondary side of the first and/or the second cooling heat
exchanger 32, 33. The
heating liquid is heated by conveying the heating liquid through the heating
means 21 of the
operated heat pump 20, and the cooling liquid is cooled by circulating the
heating liquid
through the cooling means 22 of the operated heat pump 21. In this way, the
heating liquid
may be circulated between the heating means 21, and the first heating heat
exchanger 23
and/or the second heating heat exchanger 26, and the cooling liquid may be
circulated be-
tween the cooling means 22, and the first cooling heat exchanger 32 and/or the
second cooling
heat exchanger 33.
Based on heating demand for the first and second pasteurizing lines 2, 3, the
heated heating
liquid from the heating means 21 of the heat pump 20 may be fed into the upper
region of the
heating liquid buffer tank 39, and heating liquid may be fed back into the
heating means 21 of
the heat pump 20 from a lower region of the heating liquid buffer tank 39,
thus circulating the
heating liquid between the heating means 21 and the heating liquid buffer tank
39. Such pro-
cedure is advantageous in case of low heating demand in the pasteurizing lines
2, 3, as ther-
mal energy generated in the heating means 21 can temporarily be stored in the
heating liquid
CA 2996922 2018-02-28
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buffer tank 39 for later use, by rising the overall temperature level of the
heating liquid in the
heating liquid buffer tank 39.
Based on heating demand for the first and second pasteurizing lines 2, 3,
heating liquid may
then be fed into the first heating heat exchanger 23 and/or the second heat
exchanger 26 from
the upper region of the heating liquid buffer tank 39 in order to heat the
process liquid with a
high temperature level of the first pasteurizing line 2 and/or the second
pasteurizing line 3.
Heating liquid from the first heat exchanger 23 and/or from the second heat
exchanger 26 may
be fed back into the lower region of the heating liquid buffer tank 39. Such
procedure is of
particular advantage, when a high heating demand exists in the first and/or
second pasteuriz-
ing lines 2, 3.
As depicted in Fig. 2, the heated heating liquid from the heating means 21 may
be fed into the
heating liquid buffer tank 39 via the hollow profile body 43 arranged within
the upper region
of the heating liquid buffer tank 39. Heating liquid may be fed back from the
heating liquid
buffer tank 39 into the heating means 21 via the further hollow profile body
44 arranged with-
in the lower region of the heating liquid buffer tank 39.
Based on heating demand for the first and second pasteurizing lines 2, 3, the
heating liquid
from the upper region of the heating liquid buffer tank 39 may then be fed
into the first heat-
ing heat exchanger 23 and/or the second heating heat exchanger 26 via the
hollow profile
body 43 in the upper region of the heating liquid buffer tank 39, and heating
liquid from the
first and/or second heating heat exchanger 23, 26 may be fed back into the
lower region of the
heating liquid buffer tank 39 via the further hollow profile body 44.
By using the hollow profile bodies 43, 44 both for loading and unloading, the
heating liquid
buffer tank 39 can be operated as layered storage tank in a very efficient
way. A stable long-
term operation of the heat pump at high COP can also be provided in this way.
For determination of the actual heating demands in the pasteurizing lines 2,
3, temperature
sensors (not shown) can be arranged at suitable positions in the pasteurizing
lines 2, 3.
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Based on cooling demand for the first and second pasteurizing lines 2, 3,
cooled cooling liq-
uid from the cooling means 22 of the heat pump 20 may be fed into a lower
region of a cool-
ing liquid buffer tank 45, and cooling liquid may be fed back into the cooling
means 22 of the
heat pump 20 from an upper region of the cooling liquid buffer tank 45, thus
circulating the
cooling liquid between the cooling means 22 and the cooling liquid buffer tank
45. Such pro-
cedure is convenient in case of low cooling demand in the pasteurizing lines
2, 3, as the cool-
ing capacity of the heat pump can nevertheless be used to lower the overall
temperature level
of the cooling liquid in the cooling liquid buffer tank 45 in this way.
Based on cooling demand for the first and second pasteurizing lines 2, 3,
cooling liquid may
then be fed into the first cooling heat exchanger 32 and/or the second cooling
heat exchanger
33 from the lower region of the cooling liquid buffer tank 45 in order to cool
the process liq-
uid with a low temperature level of the first pasteurizing line 2 and/or the
second pasteurizing
line 3, and cooling liquid from the first cooling heat exchanger 32 and/or
from the second
cooling heat exchanger 33 may be fed back into the upper region of the cooling
liquid buffer
tank 45. Such procedure is of particular advantage, when a high cooling demand
exists in the
first and/or second pasteurizing lines 2, 3.
As is depicted in Fig. 2, the cooled cooling liquid from the cooling means 22
may be fed into
the cooling liquid buffer tank 45 via the hollow profile body 49 arranged
within the lower
region of the cooling liquid buffer tank 45. cooling liquid may be fed back
from the cooling
liquid buffer tank 45 into the cooling means 22 via the further hollow profile
body 50 ar-
ranged within the upper region of the cooling liquid buffer tank 45.
Based on cooling demand for the first and second pasteurizing lines 2, 3, the
cooling liquid
from the lower region of the cooling liquid buffer tank 45 may then be fed
into the first cool-
ing heat exchanger 32 and/or the second cooling heat exchanger 33 via the
hollow profile
body 49 in the lower region of the cooling liquid buffer tank 45, and cooling
liquid from the
first and/or second cooling heat exchanger 32, 33 may be fed back into the
upper region of the
cooling liquid buffer tank 45 via the further hollow profile body 50. By using
the hollow pro-
file bodies 49, 50 both for loading and unloading, the cooling liquid buffer
tank 45 can be
operated as layered storage tank in a very efficient way. A stable long-term
operation of the
heat pump at high COP can also be provided in this way.
CA 2996922 2018-02-28
,
,
- 30 -
For determination of the actual cooling demands of the pasteurizing lines 2,
3, temperature
sensors can be arranged at suitable positions in the pasteurizing lines 2, 3.
Another embodiment of the pasteurizing plant 1 is shown in Fig. 1. Dependent
on operating
conditions, particular high cooling demands may arise in the pasteurizing
lines 2, 3. To cover
such cooling demand peaks, the pasteurizing plant 1 may comprise at least one
additional
cooling device 54 for further cooling the process liquid(s) with a low
temperature level of the
first and/or the second pasteurizing lines 2, 3. Within the embodiment
depicted in Fig. 1, both
the first pasteurizing line 2 and the second pasteurizing line 3 comprise an
additional cooling
device 54 for cooling the respective process liquid. In the embodiment
depicted in Fig. 1, in
each of the pasteurizing lines 2, 3, the additional cooling device 54 is an
air-cooled or water-
cooled cooling tower with a heat exchanger 55 for conveying through the
respective process
liquid(s). The heat exchangers may for example be in operative flow connection
with the re-
spective cold collection tanks 18 of the pasteurizing lines 2, 3.
During operation of the pasteurizing plant 1, the process liquid(s) with a low
temperature lev-
el of the first and/or the second pasteurizing lines 2, 3 may be cooled
further by means of the
at least one additional cooling device 54, by conveying the process liquid(s)
through a heat
exchanger 55 of the at least one air-cooled or water-cooled cooling tower. By
means of the
heat exchangers 55 of the cooling devices 54 depicted in Fig. 1, a
contamination of the pro-
cess liquid(s) during cooling, as for example potentially caused by direct
contact with cooling
air, can be prevented.
For further heating up the temperature of process liquid, in particular for
the process liquid
flows to be fed into the respective pasteurizing zones 9, 10 of the
pasteurizing lines 2, 3, addi-
tional heating devices 56 may also be provided in the pasteurizing lines 2, 3.
As shown in Fig.
1, such additional heating devices 56 may for example be arranged in the
output lines 29 for
the process liquids, upstream of the heating heat exchangers 23, 26. The
additional heating
devices 56 may for example be heat exchangers chargeable with hot water vapor.
For simplicity and clarity reasons, the exemplary embodiments shown in Fig. 1
and Fig. 2
comprise just two pasteurizing lines 2, 3, and the invention has been
described by reference of
CA 2996922 2018-02-28
- 31 -
such a pasteurizing plant I. A person skilled in the art will appreciate, that
the same principle
can of course also be applied for pasteurizing plants comprising more than two
pasteurizing
lines, for example by adding a third and a fourth pasteurizing line, and so
on. Such third and
fourth pasteurizing lines could be assigned third and fourth heating heat
exchangers operative-
ly connectable with the heating means of the heat pump, and could be assigned
third and
fourth cooling heat exchangers operatively connectable with the cooling means
of the heat
pump. The meaning of the terms "operatively connected" and "operative flow
connection"
throughout this specification is, that a respective liquid may be circulated
between "operative-
ly connected" elements or elements in "operative flow connection".
The embodiments illustrated as examples represent possible variants and it
should be pointed
out at this stage that the invention is not specifically limited to the
variants specifically illus-
trated, and instead the individual variants may be used in different
combinations with one
another and these possible variations lie within the reach of the person
skilled in this technical
field given the disclosed technical teaching.
The protective scope is defined by the claims. However, reference may be made
to the de-
scription and drawings with a view to interpreting the claims. Individual
features or combina-
tions of features from the different examples of embodiments described and
illustrated may
also be construed as independent embodiments of the solutions proposed by the
invention.
The objective underlying the individual solutions proposed by the invention
may be found in
the description.
For the sake of good order, finally, it should be pointed out that, in order
to provide a clearer
understanding of the structure, elements are illustrated to a certain extent
out of scale and/or
on an enlarged scale and/or on a reduced scale.
CA 2996922 2018-02-28
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List of reference numbers
1 Pasteurizing plant 36 Output line
2 Pasteurizing line 37 Input line
3 Pasteurizing line 38 Output line
4 Container 39 Heating liquid buffer tank
Transporting means 40 Output
6 Transorting direction
41 Input
7 Heating zone
42 Conveying means
8 Heating zone
43 Hollow profile body
9 Heating zone
44 Hollow profile body
Heating zone
45 Cooling liquid buffer tank
11 Cooling zone
46 Output
12 Cooling zone
47 Input
13 Irrigation means
48 Conveying means
14 Liquid conveying device
49 Hollow profile body
Bottom area
50 Hollow profile body
16 Recuperation line
51 Heating circuit
17 Hot collection tank
52 Cooling circuit
18 Cold collection tank
53 Temperature sensor
19 Metering device
54 Cooling device
Heat pump
55 Heat exchanger
21 Heating means
56 Heating device
22 Cooling means
23 Heating heat exchanger
24 Liquid transport line
Shut-off means
26 Heating heat exchanger
27 Conveying means
28 Input line
29 Output line
Input line
31 Output line
32 Cooling heat exchanger
33 Cooling heat exchanger
34 Conveying means
Input line
CA 2996922 2018-02-28
