Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to a method of manufacturing
confectionery and is more particularly concerned with a method
of manufacturing confectionery in which a confection, e.g.
chocolate, in a liquid phase is thoroughly mixed with gas
under pressure and is then passed through a depositor into a
zone of lower pressure so that gas expansion occurs to produce
an expanded product which requires further cooling for more
rapid s~lidification. The invention also relates to a deposi-
tor for use in such a metnod.
This application is a divisional application of
copending Canadian application No. 438,803 filed October 12,
1983.
We have found, in the manufacture of an expanded
confection, that, for volume production, it is difficult to
produce a product which is evenly expanded to the desired
extent. We have also found that the manner in which the mix-
ture of liquid confection and gas is discharged through the
depositor has a substantial effect on the quality of the
expanded product insofar as cell uniformity and size are con-
cerned.
The present invention provides an improved process
whereby by cell uniformity and size can be strictly con-
trolled.
According to a first aspect of the present invention
as disclosed and claimed in copending Canadian application No.
438,803, there is provided a method of manufacturing a confec-
tion comprising the steps of thoroughly mixing a confection in
liquid phase form with gas under pressure, passing the mixture
of liquid phase confection and gas through a depositor into a
zone of lower pressure s~ as to allow the confection to
expand, and allowing the expanded confection to solidify to
produce a solid expanded confection, wherein the depositor
~L~499~7
includes at least one annular orifice through which said mix-
ture is discharged, the annular orifice discharging into said
region of lower pressure and having a length which is not
greater than its diameter, and wherein the depositor includes
a valve for controlling flow of said mixture to said annular
outlet orifice, said valve including an annular valve seat and
a valve member movable into and out of engagement with the
valve seat.
~ccording to a second aspect of the present inven-
tion as disclosed and claimed in copending Canadian applica-
tion No. 438,803, there is provided apparatus for carrying out
the method of the invention, said apparatus comprising means
for mixing a confection in liquid phase form with gas under
pressure, a depositor for receiving the mixture and for dis-
charging said mixture to a lower pressure zone, and means for
receiving said mixture from the depositor and allowing said
mixture to cool to form an expanded confection, wherein the
depositor includes at least one annular orifice through which
said mixture is discharged, the annular orifice discharging
into said region of lower pressure and having a length which
is not greater than its diameter, and a valve associated with
said at least one annular orifice, said valve including an
annular valve seat surrounding said annular orifice and a
valve member movable into and out of engagement with the valve
seat.
Preferably, the inner peripheral wall of the annular
orifice is defined by an extension of the valve member.
In one embodiment, the valve seat is defined by a
frusto conical surface which merges with an upstream end o~
the outer peripheral wall of the annular orifice, and the mov-
able valve member has a valve seat-engaging edge which is
rounded.
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In another embodiment, the valve seat is defined by
a rounded surface which merges with an upstream end of
-- 3
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the outer peripheral wall of the annular oriEice, and
the valve member has a frusto conical surface
engageable with the valve seat.
Typically, in either embodiment, the rounding on the
valve mem~er or the valve seat, as the case may be, is
of a radius of 0.5 to 2 mm, peeferably 1 mm.
It is preferred for the diameter of the inner
peripheral wall of the annular orifice to be 1/2 to 2/3
that of the annular contact line between the valve
member and the valve seat.
In a highly preferred embodiment, a multiplicity of
such annular orifices and associated valves are
provided in the depositor, and the valves are so
controlled that they are opened and closed in sequence
so that at any one time during operation of the
process, the same number of valves are open, the number
being such as is required to give the period of switch
off during the cycle to produce the desired length of
deposit.
Preferably also, more than one depositor is fed with
said mixture of liquid phase confection and gas.
~ith such a construction of annular outlet orifice, we
have found that the shear which is imparted to the
mixture as it is expanding during passage through the
orifice is minimised because of the short length of the
passage through which the mixture is constrained to
pass and, for a given throughput, produces less of a
velocity profile across the passage than an outlet
orifice of circular cross-section. Large velocity
profiles across the outlet orifice have been found to
give uneven expans~on of the confection.
9947
According to a third aspect of the present inven-
tion, there is provided a depositor for use in a method of
manufacturing confectionary according to the present inven-
tion, said depositor comprising a body for receiving a mixture
of a confection in liquid phase forrn and gas, said body having
at least one outle-t orifice through which said mixture is dis-
charged, in use, the annular orifice having a length which is
not greater than its diameter, and a depositor further includ-
ing a valve having an annular valve seat surrounding said
annular orifice and a valve member movable into and out of
engagement with the valve seat.
Where a material is to be deposited into a multi-
plicity of moulds from a series of orifices in one or more
depositors, problems can arise in obtaining products of con-
sistent quality with existing depositors if the material to be
deposited is pressure sensitive. An example of such a mate-
rial is a foamed confection such as foamed chocolate. Fluctu-
ations in the pressure of the supply causes pressure varia-
tions in the material being moulded and undesirable variations
in the density and cell size of the foamed product as well as
inconsistencies in the weight of material deposited in the
moulds.
~ In a fourth aspect of the present invention this
disadvantage is obviated or mitigated.
According to the present invention, there is pro-
vided apparatus for depositing a material from a multiplicity
of outlets into respective rows of moulds, said apparatus com-
prising at least one depositor containing a multiplicity of
outlets and respective valves for controlling the flow of
material through said outlets; a conveyor for conveying rows
of
lZ49947
moulds past the depositor; means for supplying
material under pressure to said at least one
depositor; and control means for periodically opening
and closing the valves in a sequence such that, in use,
the number of valves which are open and the number of
valves which are closed in said at least one depositor
does not vary.
~ith such an arrangement, pressure fluctuations in the
supplying means caused by more valves being open at
some times than at other times in the operating cycle
are obviated.
In a preferrred embodiment, the periodic valve opening
and closing means is arranged so that, at any time only
one valve in the or each depositor is closed whilst
the remaining valves in the or each depositor are open.
Preferably, the conveyor is continuously movable, the
moulds associated with the or each depositor are
arranged in rows which extend longitudinally of the
direction of travel of khe conveyor with the moulds in
the respective rows being aligned in a direction at
right angles to said direction of travel; said at
least one depositor is inclined at an acute angle to
the direction of alignment oE the rows; and said valve
opening and closing means is controlled so as to
cause material to be discharged from said depositor
into a respective one of the sets of aligned moulds
during each cycle of operation.
Preferably, also a plurality of depositors is provided,
and the valve opening and closing means is
arranged to cause a respective one of the valves in
every head to be periodically opened and closed
simultaneously. ~th such an arrangement, it is
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convenient to provide a separate control valve for controlling
operation of each set of valves in the heads which are to be
opened and closed simultaneously. Preferably, each control
valve is arranged to be operated by a respective cam, the cams
being mounted on a common shaft driven from the conveyor and
being equi-angularly staggered around the shaft.
The pres~nt invention further provides a method of
depositing a material from a multiplicity of outlets into
respective rows of moulds, comprising the steps of supplying
material under pressure to at least one depositor containiny a
multiplicity of outlets and respective valves for controlling
the flow of material through said outlets, depositing said
material into said moulds through said orifices, and periodi-
cally opening and closing the valves in a sequence such that
the number of valves which are open and the number of valves
which are closed does not vary. Suitably the valves are
opened and closed such that, at any time, only one valve in
the or each depositor is closed whilst the remaining valves in
the or each depositor are open. Desirably said material being
deposited is a foamed confection. More desirably the method
includes the step of mixing gas under pressure with a
confection, and supplying the resultant mixture to said at
least one depositor so that foaming of the confection occurs
as a result of pressure releases upon discharge through said
outlets.
An embodiment of the present invention will now be
described, by way of example, with reference to the accompany-
ing drawing, in which:-
Fig. 1 is a schematic illustration of apparatus for
manufacturing aerated chocolate according to the presentinvention to illustrate the principles of the present inven-
tion;
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Fig. 2 is a cross-sectional view through a depositor
used in the apparatus of Fig. 1, and showing schematically a
control for such deposi-tor;
Fig. 3 is a plan view of four depositors forrning
part of a practical embodiment of apparatus for manufacturing
aerated chocolate according to the present invention;
Fig. 4 is a schematlc circuit diagram showing a typ-
ical pneumatic control circuit, for a respective pneumatically
operated valve in each of the four depositors of Fig. 3;
Fig. 5 is a front view of a mechanism for operating
control valves in six pneumatic circuits of the type illus-
trated in Fig. 4; and
- 7a -
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Fig. 6 is an end view of the mechanism of Fig. 5.
RefeLring now to Fig. 1, the apparatus comprises a pump
1 whl~h a~d~ tempe~ed Ghoaolate along line 2 to a
mlxar ~ o ~ pr3~ ~ b~own ~yp~ ~a~ ~smple ~ m1xer
sold under the code E or G by rlONDO~IIX). Carbon dloxlde
under pressure is fed via a line 4 into the line 2 and
is intimately mixed with the tempered chocolate in the
mixer 3. It will be appreciated that the tempered ~
chocolate is maintained at an elevated temperature such
that it is in a liquid state. The mixture of liquid
chocolate and dissolved carbon dioxide is discharged
from the mixer and is passed via line 5 to a
depositor 6 from which it is discharged into moulds 7
which are arranged in six parallel rows extending
longitudinally of a COnVQyOr 8 which moves the moulds 7
under the depositor 6. The depositor 6 has six outlets
which discharge into the respective rows of moulds 7.
Discharge is arranged to occur such that, at any one
time, five of the outlets are open whilst the other is
closed, the outlets being closed in turn, as will be
described hereinafter. In order to maintain the
required pressure conditions within the system, a
pressure relie valve 3 controls flow of the mixture
through a return bypass 10. In this way, the amount of
deposit is controlled. In the arrangement according to
Fig. 1, only one depositor 6 has been shown. In
practice, four such depositors will be provided, each
discharging into an arrangement of six rows of moulds
on a respective conveyor, as will be apparent later.
In accordance with usual practice, the lines through
which the liquid chocolate is passed and the depositor
itself are jacketed and supplied with warm water to
maintain the chocolate in a liquid phase up to the
depositor 6. ~\
~9947
Referring now to Flg. 2, the depositor 6 inc~udes a
body 12 in which six outlet passages or orifices 13 and
associated valves 14 are provided. The outlet orifices
13 and associated valves 14 are identical and, for the
sake of convenience, only one such outlet orifice 13
and associated v~lve will be described. The outle~
orifice 13 is of annular shape, the outer peripheral
wall of the orifice 13 being defined by a hardened
insert 15 which is disposed with its upper end in a
circular recess 16 in the body 12 and with its lower
end screw fitted into the body 12. The inner
peripheral wall of the annular orifice 13 is defined by
a cylindrical projection 18 of circular cross-section
which extends from the lower end of a valve member 19
which is vertically slidable in the bod-y 12. The upper
end of the valve member 19 is formed
as a piston 20 which is slidable in a further recess 21
in the body 12. The further recess 21 defines a
cylinder which is arranged to be supplied with air for
piston controlling purposes via one or other of ports
22, 23 disposed on opposite sides of the piston 20. In
this embodiment, the further recess 21 has a smooth
bore and the piston 20 is fitted with annular sliding
seals 24. At its lower end, in the region of the
projection 18, the valve member 19 has an annular
shoulder which is rounded to 1.0 mm radius. This
shoulder 25 is engageable with a frusto-conical valve
seat 26. The valve seat 26 is downwardly ta~oering and
is provided in the insert 15 so that its lower, smaller
diameter end merges with the upper end of that portion
oE the insert 15 defining the outer 2eripheral wall oE
the annular orifice 13. A manually adjustable screw 27
3L2~99~L7
and associated locking nut 2B are provided at the upper
end of the body 12, the screw 27 e~tending into the
further recess 21 so as to define an abutment 29 for
limiting upward movement of the valve member 19 away
from the valve seat 26. A sealing ring 30 surrounds the
screw 27 to prevent unwanted escape of air from the
further recess 21. The intermediate portion of the
valve member 19 is machined so as to be a sliding fit
in a bore 31 extending between the recess 16 and the
Eurther recess 21. Sealing rings 32 are provided in the
bore 31 to prevent escape of air downwardly and escape
of material being deposited upwardly and into the
recess 21. The body 12 is slotted at 50 so that the
region of the bore 31 between the sealing rings 32 is
e~posed to atmosphere. This allows material being
deposited to leak to atmosphere rather than to leak
into the recess 21 in the event of failure oE the lower
sealing ring 32.
The body 12 is provided with an inlet passage 33
leading to each recess 16, each inlet passage 33 being
connected with a common manifold 34 fitted with a water
jacicet 35 for maintaining material being passed to the
depositor 6 at the required temperature. The manifold
34 is connected with the line 5.
Each of the ports 22, 23 is connected via a respective
air line 36, 37 and all of the`air lines 36, 37 lead to
a multiway distributor and sequencing valve assembly 38
connected with an air supply via line 39. The valve
assembly 38 is controlled by an electrical or pneumatic
control unit 40 to perform the aforesaid sequencing of
the valves 14 in each depositor 6 so that, at any one
time, one of the valves 14 in each depositor 6 is closed
whilst the others remain open. In the condition shown
in Fig. 2, the val\'ve 14 is shown closed. When it is the
~L~z~94~7
turll o[ the illustratecl valve to be opened, a signal is
passed Erom the control unit 40 to the valve assembly
3~3 which causes line 39 to be connected with line 37
and line 36 to be exhausted to atmosphere. This causes
the piston 20 and thereby the valve member 19 to be
lifted until the upper end of the valve mernber 19
engages against the abutment 29. Liquid chocolate and
dissolved carbon dioxide which has been fed to the
manifold 34 by the line 5 and which fills the inlet
passage 33 and the recess 16 is then permitted to flow
through the outlet orifice 13 to be discharged into a
mould 7 which is passing thereunder. Because of the
relatively limited axial extent of the outlet oriEice
13 relative to its diameter (not greater than 100~ of
the outer diameter of the orifice 13), the material
being deposited is subjected to a relatively even shear
across the cross-section of the orifice 13. As it
passes throuyh the orifice 13 and discharges externally
of the depositor 6, the material is exposed to
atmospheric pressure and so experiences a pressure
release which causes carbon dioxide dissolved in the
chocolate to come out of solution and thereby expand
the material as it is being deposited in the mould 7.
Even expansion of the material occurs in view of the
relatively limited axial extent of the orifice 13. In
the embodiment illustrated, the axial extent of the
orifice 13 is only 50~ of its outer diameter so that
substantially parallel flow of the material through the
orifice 13 is only just established. It will be
appreciated that the material passing into the outlet
orifice 13 via the valve seat 26 will have a radially
inward component of movement as a result of passage
from the larger diameter recess 13. This radially
inward component of movement of the material stops upon
flowing through the orifice 13. The annular nature of
the orifice 13 al~ws relatively high flow rates to be
~Zq~9947
12
obtained without incurring an undue di~ference in
velocity profile across the cross-section of the
orifice 13. Eligh velocity profiles are to be avoided
because the Applicants have found that this leads to
uneven expansion oE the material.
The material issues from the orifice 13 into chocolate
shells in the moulds 7 and subsequent cooling of the
material until it solidifies is eEfected in the moulds
7 which are vibrated in a manner known per se to ensure
filling oE the moulds. ~fter solidifying, the resultant
expanded chocolate confection can then be demoulded and
subsequently packed.
In the above described embodiment, the pressure within
the mixer 3 and line 5 is maintained at a fixed
pressure between one and a half and two atmospheres
(152-203kPa). The exact pressure will depend on the
type of expansion that is required. The lift on each
valve member 19 is controlled by the screw 27 so that
up to about 8 kg per minute of material pass through
each orifice 13, the amounts passing through each
orifice 13 being controlled so as to be the same by
appropriate adjustment of the lift of each valve member
19 using manually adjustable screw 27. Typically, the
lift on each valve member is about 1.1 mm. In this
embodiment, the length of each orifice 13 is 10 mm, the
outer diameter thereof is 16 mm, the inner diameter of
each outlet orifice 13 (ie the diameter of the
projection 18) is 10 mm and the diameter of the annular
contact line between the shoulder 25 and the frusto
conical valve seat 26 is 19 mm. ~e have found that by
using the aforesaid sequencing of the valves 14, it is
relatively simple to keep the system pressure constant
at one and a half atmospheres (152 kPa)or at any other
clesirecl pressure up to 2 atmospheres (203 kPa) and this
~Z49910~7
also assists in obtaining even expansion of the
material .
Referring now to Fig. 3, there is shown a four
depositor head arrangement in which each depositor 6a,
6b, 6c and 6d i5 oE the type described with reference
to Fig. ~. Each depositor 6a to 6d is arranged to file
a respective set of 6 rows of moulds (not shown in Fig.
3) or conveyor 8. All the rows of moulds extend
parallel to the direction of movement of the conveyor 8
and the moulds in each set are aligned in a direction
perpendicular to the direction of extent of the rows
(see Fig. l). In the embodiment of Fig. 4, the
depositors 6a to 6b are inclined at an acute angle of
about 30 relative to the aforesaid perpendicular
direction so that, having regard to the speed of travel
of the moulds and the sequencing of operation of the
valves in each depositor, one set of aligned moulds is
filled during each cycle of operation o each depositor
and, at any instant, four moulds (one by each
depcsitor) are being filled.
The control circuit for simultaneous opening and
closing of respective valves in the four depositors 6a
to 6d is illustrated in Fig. 4, it being understood
that five other identical control circuits are
provided, one for each of the remaining valves in the
respective depositors 6a to 6d. The pneumatic circuit
includes a pneumatic pressure supply line 00 from a
pressure source 101 common to all the six control
circuits. The line 100 is connected to two pneumatic
YES gates 102 and ]03 and two pneumatic NOT gates 104
and 105. The line 100 is also connected to an
pneumatic valve 106 which is normally closed ie biassed
to a position in which pressure is not transmitted.
The valve 106 is p~ovided with an operating arm
~2~9~7
terminating in a roller-type cam follower 107 which
engages a respective rotary cam 108. The valve 106 is
connected with each of the gates 102 to 105 so as to
transmit pressure thereto when the cam 108 is in a
position in which it biasses the operating arm 107 to a
position in which the valve 106 is open. ~'he form of
the cam 108 is such that the valve 106 is open for 300
of the rotary movement of the cam ~08 but closed for
the remaining 60 of rotary movement o the latter.
However, provision is made for adjustment of this
angle. Cam 108 is driven from the conve~or 8 in a
manner to be described.
~hen the valve 106 is opened (as shown in Fig. 4),
pressure is transmitted to the gates 102 to 105. Under
these conditions, the YES gates 102 and 103 permit flow
of air through lines 37a to 37d to lift the four
pistons 20a to 20d in the Eour depositors 6a to 6d
simultaneously. This opens the valves of the
associated nozzles. It will be appreciated that flow
of air to the pistons 20 through lines 36 will not be
permitted via the NOT gates 104 and 105 under these
circumstances. ~hen the cam 108 has rotated to a
position to release the cam follower 107, the pneumatic
valve 106 is allowed to close. Under these conditions,
the NOT gates 104 and 105 permit flow of air to the
pistons 20a to 20d whilst the YES gates 102 and 103 no
longer permit flow of air to the pistons 20a to 20d
through the lines 37a to 37d. The result of this is
that the pistons 20a to 20d are lowered to close the
valves of the associated noæzles so that mould filling
through such nozzles is terminated.
Referring now to Figs. 5 and 6, the six cams 108
respectively associated with the six pneumatic contro]
circuits are mounted on a common rotary shaft 109 in
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equi-angularly staggered relationship. It will thus be
appreciated that Eor each 60 angle of rotary movement
oE the shaft 109, a respective one of the pistons 20 in
each of the four depositors will be in a lowered
position whilst the remaining ones will be in a lifted
position. The four pistons 20a to 20b which are
operated simultaneously are those which are provided at
corresponding locations in the four depositors and the
arrangement is such that during rotation of the shaft
109 the valves in each depositor are o~ened
sequentially starting from the most upstream valves and
ending at the most downstream valve before repeating
the cycle.
In order to ensure synchronisation of the depositors 6
with the movement of the moulds 7 on the conveyor 8 the
shaft 109 is driven from a lay shaft 119 of the
conveyor, toothed pulleys 111 to 114 of which pulley
111 is mounted on layshaft 110 and pulley 114 is
mounted a shaft 115, and a belt 116 passing around
pulleys 111 to 114. The shaft 115 is operably
connected to the shaft 109 via a single angularly
engagement position electromagnetic clutch 117
(manufactured by Monning ~loff, of Germany) and a phase
variator 118 in the form of a differential gearbox
fitted with a rotary control knob 119 for advancing or
retarding the deposits relative to the moulds in use.
This knob 119 alters the angular position of the shaft
109 relative to the shaft 115.
The clutch 117, variator 118, shaft 109, cams 108 and
six plates 120 carrying the gates 102 to 105 and the
valve 106 of the respective pneumatic circuits are all
mounted in a housing 121 mounted on a support frame 122
above the conveyo~ 8 ~not shown) in Figs. 5 and 6).
~10unted on top of the housing 121 is an electric motor
122 which also drives the shaft 109 via a variable speed
lZ~9g47,
16
drive 123, a sprag clutch 124 and a belt 125. The
motor 122 is not used ciuriny normal operation oE the
apparatus and the sprag clutch 124 free which when the
shaft 1~9 is driven by the shaft 115 to prevent power
being transmitted to the drive 123. The motor 122 is,
however, used for testing and setting up purposes when
it is not desired to have the conveyor 8,running.
