Note: Descriptions are shown in the official language in which they were submitted.
CA 02857852 2014-07-25
HEAT EXCHANGER FOR COOLING BULK SOLIDS
FIELD OF THE INVENTION
[0001] The present disclosure relates to a heat exchanger for cooling bulk
solids, for example, metal powders, ash, coke, coals, carbon powders, and
graphite
powders.
BACKGROUND
[0002] Heat exchangers are used to cool bulk solids that have a high
temperature and that flow, under the force of gravity, through the heat
exchanger.
The operation life of known heat exchangers is limited because indirect
cooling
elements of the heat exchanger become worn as the bulk solids flow through the
heat exchanger. Improvements to heat exchangers to extend their operational
life
are therefore desirable.
SUMMARY
[0003] According to one aspect of an embodiment, a heat exchanger includes
a housing including an inlet for receiving bulk solids having a first
temperature, and
an outlet for discharging the bulk solids. A plurality of spaced apart,
substantially
parallel heat transfer tubes are disposed within the housing between the inlet
and
the outlet, for cooling the bulk solids that flow from the inlet, to spaces
between
heat transfer tubes, to the outlet, to a second intermediate temperature, and
a
plurality of spaced apart, substantially parallel heat transfer plate
assemblies
disposed within the housing and interposed between the plurality of heat
transfer
tubes and the outlet for further cooling the bulk solids that flow from the
spaces
between heat transfer tubes, to spaces between the heat transfer plate
assemblies,
and to the outlet, to a third temperature.
[0004] The first temperature may be between about 400 C and about
2400 C, the second intermediate temperature may be less than the first
temperature and greater than or equal to about 400 C, and the third
temperature
may be about 400 C or less. The first ones of the plurality of heat transfer
tubes
may be arranged in a first row, and second ones of the plurality of heat
transfer
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tubes may be arranged in a second row such that the heat transfer tubes of the
second row are spaced from the heat transfer tubes of the first row. Each heat
transfer tube of the second row may be disposed between adjacent heat transfer
tubes of the first row. The third ones of the plurality of heat transfer tube
assemblies may be arranged in a third row such that the heat transfer tube
assemblies of the third row are spaced and aligned with respective heat
transfer
plate assemblies of the first row.
[0005] According to another aspect of an embodiment, the heat exchanger
includes a refractory lining disposed within the housing between a first
sidewall of
the housing and the heat transfer tubes adjacent the first sidewall of the
housing
for cooling the bulk solids that flow between the first sidewall of the
housing and
the first heat transfer tubes located adjacent the first sidewall of the
housing. The
refractory lining may also be disposed within the housing between an opposing
second sidewall of the housing and the heat transfer tube assemblies located
adjacent the second sidewall of the housing to reduce the chance of
overheating
the housing.
[0006] According to another aspect of an embodiment, a first end of the
heat
transfer tube assemblies may pass through the first sidewall of the housing
and a
second end of the heat transfer tube assemblies pass through the second
sidewall
of the housing. The first end of the heat transfer tube assemblies of the
first row
may be coupled to the first sidewall of the housing by a first seal.
[0007] According to another aspect of an embodiment, the heat exchanger
also includes a cooling fluid inlet manifold in fluid communication with each
first
seal for providing cooling fluid into each heat transfer tube assembly of the
first
row. The second end of each heat transfer tube assembly of the first row may
be in
fluid communication with the second end of each heat transfer tube assembly of
the
second row for providing cooling fluid into each heat transfer tube assembly
of the
second row. The first end of each heat transfer tube assembly of the second
row
may be coupled to the first sidewall of the housing by a second mechanical
seal.
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[0008] According to another aspect of an embodiment, the heat exchanger
also includes a cooling fluid discharge manifold in fluid communication with
each
second seal for receiving cooling fluid discharged from each heat transfer
tube
assembly of the second row. The cooling fluid may be liquid. The liquid may be
one
of water and thermal oil. Alternatively, the cooling fluid may be a gas under
pressure. Each of the plurality of heat transfer plate assemblies are low
temperature heat transfer plate assemblies. Each of the plurality of heat
transfer
plate assemblies may be high temperature heat transfer plate assemblies.
[0009] According to another aspect of an embodiment, the heat exchanger
also includes a plurality of spaced apart, substantially parallel low
temperature heat
transfer plate assemblies disposed within the housing and interposed between
the
plurality of high temperature heat transfer plate assemblies and the outlet
for
further cooling the bulk solids that flow from the spaces between high
temperature
heat transfer plate assemblies, to spaces between the low temperature heat
transfer plate assemblies and to the outlet, to a fourth temperature. The
first
temperature may be about 2400 C, the second intermediate temperature may be
less than the first temperature and greater than or equal to about 400 C, and
the
third temperature may be about 400 C or less.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Embodiments of the present invention will be described, by way of
example, with reference to the drawings and to the following description, in
which:
[0011] FIG. 1 is a partially cut away front perspective view of a heat
exchanger for cooling bulk solids in accordance with an embodiment;
[0012] FIG. 2 is a partially cut away rear perspective view of the heat
exchanger of FIG. 1;
[0013] FIG. 3 is a top view of a top bank of heat transfer tubes of the
heat
exchanger of FIG. 1;
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[0014] FIG. 4 is an end view of an example embodiment of a heat transfer
tube stack of the heat exchanger of FIG. 1;
[0015] FIG. 5 is a side view of a portion a heat transfer tube of a top
heat
transfer tube bank of the heat exchanger of FIG. 1, that illustrates an
example of a
seal between an end of a heat transfer tube and an end of a fluid line;
[0016] FIG. 6 is an exploded perspective view of an example embodiment of
a
seal of the heat exchanger of FIG. 1;
[0017] FIG. 7 is a top view of a top bank of heat transfer plate
assemblies of
the heat exchanger of FIG. 1;
[0018] FIG. 8 is a perspective view of an example of a heat transfer
plate
assembly of the heat exchanger of FIG. 1;
[0019] FIG. 9 is a sectional view of the high temperature heat transfer
plate
assembly of FIG. 8;
[0020] FIG. 10 is a top view of a bank of heat transfer plate assemblies
of the
heat exchanger of FIG. 1; and
[0021] FIG. 11 is a sectional view of an example of a heat transfer plate
assembly of the heat exchanger of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] For simplicity and clarity of illustration, reference numerals may
be
repeated among the figures to indicate corresponding or analogous elements.
Numerous details are set forth to provide an understanding of the embodiments
described herein. The embodiments may be practiced without these details. In
other instances, well-known methods, procedures, and components have not been
described in detail to avoid obscuring the embodiments described. The
description
is not to be considered as limited to the scope of the embodiments described
herein.
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[0023] The disclosure generally relates to heat exchangers for cooling
bulk
solids that have a temperature, for example, in the range of about 400 C to
about
2400 C. Examples of bulk solids include metal powders, ash, coke, coals,
carbon
powders, graphite powders, and other solids that flow under the force of
gravity.
[0024] FIG. 1 and FIG. 2 show partially cutaway front and rear
perspective
views of an embodiment of a heat exchanger for cooling bulk solids. The heat
exchanger 100 includes a housing 102 with a generally rectangular cross-
section.
The housing 102 has a top 104 and a bottom 106. The top 104 of the housing 102
includes an inlet 108 for introducing bulk solids 110 into the heat exchanger
100,
such as bulk solids 110 that have a temperature in the range of about 400 C to
about 2400 C. For example, bulk solids 110 that have a temperature of about
750 C may be introduced into the heat exchanger 100 through the inlet 108. The
bottom 106 of the housing 102 of the heat exchanger 100 is open to provide an
outlet (not shown) for discharging cooled bulk solids from the housing 102 of
the
heat exchanger 100. A vertical axis, referred to herein, extends from a center
of
the inlet 108 to a center of the outlet.
[0025] A plurality of heat transfer tubes 112 are disposed within the
housing
102, between the inlet 108 and the outlet. The heat transfer tubes 112 are
horizontally spaced apart along an axis that extends transverse to the
vertical axis
and are arranged generally parallel to each other in rows, referred to herein
as a
tube bank. In the example shown in FIG. 1 and FIG. 2, the heat exchanger 100
includes eight tube banks. The eight tube banks are arranged in a stack,
referred
to herein as tube stack 114. The tube stack 114 includes a top tube bank 116,
a
bottom tube bank 118, and six intermediate tube banks 120, 122, 124, 126, 128,
and 130. For the purpose of the present example, each heat tube bank 116, 118,
120, 122, 124, 126, 128, 130 includes five heat transfer tubes 112. Although
the
heat exchanger 100 of FIG. 1 and FIG. 2 includes eight tube banks, other
suitable
numbers of tube banks may be utilized. Also, other suitable numbers of heat
transfer tubes 112 in each tube bank may be utilized.
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[0026] The top tube bank 116 of the tube stack 114 (i.e. the heat
transfer
tube bank that is located closest to the inlet 108) is sufficiently spaced
from the
inlet 108 to provide a hopper 132 in the housing 102 between the inlet 108 and
the
top tube bank 116. The hopper 132 facilitates distribution of bulk solids 110
that
flow from the inlet 108, as a result of the force of gravity, over the heat
transfer
tubes 112 of the top tube bank 116 by disbursing the bulk solids 110 over the
entire cross-section of the heat exchanger 100 as bulk solids 110 flow from
the inlet
108 into the housing 102.
[0027] The heat exchanger 100 also includes a plurality of heat transfer
plate
assemblies for cooling bulk solids, such as solids that have a temperature
between
24000C and 4000C, referred herein to as high temperature heat transfer plate
assemblies 134. The high temperature heat transfer plate assemblies 134 are
disposed within the housing 102 and interposed between the heat transfer tubes
112 (i.e. the tube stack 114) and the outlet. The high temperature heat
transfer
plate assemblies 134 are horizontally spaced apart spaced apart along an axis
that
extends transverse to the vertical axis and are arranged generally parallel to
each
other in rows, referred to herein as an assembly bank. In the example shown in
FIG. 1 and FIG. 2, the heat exchanger 100 includes four assembly banks. The
four
assembly banks are arranged in a stack, referred herein to as an assembly
stack
136. The assembly stack 136 includes a top assembly bank 138, a bottom
assembly bank 140, and two intermediate assembly banks 142, 144. For the
purpose of the present example, each assembly bank 138, 140, 142, 144 includes
eleven high temperature heat transfer plate assemblies 134. Although the heat
exchanger 100 of FIG. 1 and FIG. 2 includes four assembly banks 138, 140, 142,
144, other suitable numbers of assembly banks may be utilized. Also, other
suitable numbers of high temperature heat transfer plate assemblies 134 in
each
assembly bank may be utilized.
[0028] The heat exchanger 100 also includes a plurality of heat transfer
plate
assemblies for cooling bulk solids that have a temperature less than 4000C,
hereinafter referred to as low temperature heat transfer plate assemblies 146.
The
low temperature heat transfer plate assemblies 146 are disposed within the
housing
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102 and interposed between the high temperature heat transfer plate assemblies
134 (i.e. the assembly stack 136) and the outlet. The low temperature heat
transfer plate assemblies 146 are horizontally spaced apart spaced apart along
the
axis that extends transverse to the vertical axis and are arranged generally
parallel
to each other in rows, referred to herein as a bank. In the example shown in
FIG. 1
and FIG. 2, the heat exchanger 100 includes a single bank 148. For the purpose
of
the present example, the bank 148 includes seven low temperature heat transfer
plate assemblies 146. Although the heat exchanger 100 of FIG. 1 and FIG. 2
includes a single bank 148, other suitable numbers of banks 148 may be
utilized.
Also, other suitable numbers of low temperature heat transfer plate assemblies
146
in the bank 148 may be utilized.
[0029] The bank 148 is sufficiently spaced from the outlet to facilitate
the flow
of bulk solids 110 through the outlet and out of the housing 102. Optionally,
the
heat exchanger 100 includes a discharge hopper 150 that is coupled to the
housing
102 at the outlet. The discharge hopper 150 is utilized to create a mass flow
or
"choked flow" of bulk solids and to regulate the flow rate of the bulk solids
110 out
of the heat exchanger 100. An example of a discharge hopper 150 is described
in
U.S. Patent 5,167,274. The term "choked flow" is utilized herein to refer to a
flow
other than a free fall of the bulk solids 110 as a result of the force of
gravity.
[0030] The tube stack 114, including the eight tube banks 116, 118, 120,
122, 124, 126, 128, 130, the assembly stack 136, including the four assembly
banks 138, 140, 142, 144, and the bank 148, are supported on support channels
152 at the bottom of the bank 148. The support channels 152 support the tube
stack 114, the assembly stack 136, the bank 148, and the weight of the bulk
solids
110 introduced into the heat exchanger 100 as the weight of the bulk solids
110 is
transferred to the heat transfer tubes 112, the high temperature heat transfer
plate
assemblies 134, and the low temperature heat transfer plate assemblies 146.
[0031] Referring to FIG. 3, a top view of the top tube bank 116 of the
heat
exchanger 100 of FIG. 1 is shown. Each heat transfer tube 112 of the top tube
bank 116 extends a width of the housing 102 between the first side wall 302
and an
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opposing second side wall 304 of the housing 102. A first end 306 of each heat
transfer tube 112 passes through an opening (not shown) in the first side wall
302
of the housing 102 such that the first end 306 extends out of the housing 102.
A
second end 308 of each heat transfer tube 112 passes through an opening (not
shown) in the second side wall 304 of the housing 102 such that the second end
308 extends out of the housing 102. The heat transfer tubes 112 of the top
tube
bank 116 are arranged generally parallel to each other with spaces between
adjacent heat transfer tubes 112. Each space between adjacent heat transfer
tubes
112 defines a passageway 310 for bulk solids 110 to flow through. Optionally,
a
heat resistant lining 312 may be disposed between a third side wall 314 of the
housing 102, and the heat transfer tube 112 located adjacent to or near the
third
side wall 314. A heat resistant lining 312 may also be disposed between a
fourth
side wall 316 of the housing 102 and the heat transfer tube 112 located
adjacent to
or near a fourth side wall 316. The fourth side wall 316 is opposite the third
side
wall 314. Also, a water-jacket skin 318 may be disposed on an outer surface of
the third side wall 314 and an outer surface of the fourth side wall 316. The
heat
resistant lining 312 is utilized to protect the water-jacket skin 318, for
example, in
areas of the water-jacket skin 318 in which water flow is not sufficient.
[0032] The heat resistant lining 312 may be made from any suitable
material
to withstand the temperatures of the bulk solids and that has sufficient
mechanical
strength to withstand flow of the bulk solids. Examples of materials for the
heat
resistant lining 312 include graphite or any other suitable insulating
material, such
as a refractory board or other fibrous or foam type board. The water-jacket
skin
318 may be made from any suitable material, such as Type 314L stainless steel
or
Type 316L stainless steel. The bottom tube bank 118 and the six intermediate
tube
banks 120, 122, 124, 126, 128, and 130 have a similar configuration as the top
tube bank 116.
[0033] Referring to FIG. 4, an end view of the tube stack 114 of the heat
exchanger 100 of FIG. 1 is shown. The heat transfer tubes 112 of the top tube
bank 116, and the heat transfer tubes 112 of the second, fourth, and sixth
intermediate tube banks 122, 126, 130 are arranged such that the heat transfer
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tubes 112 of the top tube bank 116, and the heat transfer tubes 112 of the
second,
fourth and sixth intermediate tube banks 122, 126, 130, are vertically aligned
in
columns. The heat transfer tubes 112 of the first, third, and fifth
intermediate tube
banks 120, 124, 128, and the bottom tube bank 118 are also arranged such that
the heat transfer tubes 112 of the first, third, and fifth intermediate tube
banks
120, 124, 128, and the heat transfer tubes 112 of the bottom tube bank 118 are
vertically aligned in columns.
[0034]
The first, third, and fifth intermediate tube banks 120, 124, 128, and
the bottom tube bank 118 are vertically and horizontally offset from the top
tube
bank 116 and the second, fourth, and sixth intermediate tube banks 122, 126,
130
such that the heat transfer tubes 112 of the first, third, and fifth
intermediate tube
banks 120, 124, 128, and the bottom tube bank 118 are not vertically aligned
and
not horizontally aligned with the heat transfer tubes 112 of the top tube bank
116
and the second, fourth and sixth intermediate tube banks 122, 126, 130.
Passageways 310 are provided between the heat transfer tubes 112 of the top
tube
bank 116, the heat transfer tubes of the first, second, third, fourth, fifth,
and six
intermediate tube banks 120, 122, 124, 126, 128, 130, and the heat transfer
tubes
112 of the bottom tube bank 118 for bulk solids 110 to flow through.
[0035]
The heat transfer tubes 112 of the first, third, and fifth intermediate
tube banks 120, 124, 128 and the heat transfer tubes 112 of the bottom tube
bank
118 may be horizontally and vertically offset from the heat transfer tubes 112
of
the top tube bank 116 and the heat transfer tubes 112 of the second, fourth
and
sixth intermediate tube banks 122, 126, 130 such that the heat transfer tubes
112
of the first, third, and fifth intermediate tube banks 120, 124, 128 and the
heat
transfer tubes 112 of the bottom tube bank 118 are horizontally and vertically
spaced by a suitable distance to facilitate the cooling zones between adjacent
heat
transfer tubes 112. For example, the heat transfer tubes 112 of the first,
third, and
fifth intermediate tube banks 120, 124, 128 and the heat transfer tubes 112 of
the
bottom tube bank 118 are horizontally spaced by a horizontal distance that is
half
of the distance between adjacent heat transfer tubes 112 of the top tube bank
116,
and vertically spaced by a distance that is half of the distance from a heat
transfer
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tube 112 in the top tube bank 116 to an adjacent heat transfer tube 112 in the
second intermediate tube bank 120.
[0036] Alternatively, the heat transfer tubes 112 of the top tube bank
116,
the first intermediate tube bank 120, the second intermediate tube bank 122,
the
third intermediate tube bank 124, the fourth intermediate tube bank 126, the
fifth
intermediate tube bank 128, the sixth intermediate tube bank 130, and the
bottom
tube bank 118 may be horizontally aligned in rows and vertically aligned in
columns
such that the passageways 310 extend through the entire tube stack 114.
[0037] The terms top, bottom, horizontal, and vertical are utilized
herein to
provide reference to the orientation of the heat exchanger 100 when assembled
for
use, as shown in FIG. 1. The term heat transfer tube is utilized herein to
refer to a
conduit through which fluid may flow. The heat transfer tube 112 is not
limited to a
cylindrical tube and may be any other suitable shape to facilitate fluid flow
therethrough.
[0038] Referring again to FIG. 1 and FIG. 2, the heat exchanger 100 also
includes a tube inlet manifold 154 for providing cooling fluid into each heat
transfer
tube 112 of the top tube bank 116, and into each heat transfer tube 112 of the
first
intermediate tube bank 120. The tube inlet manifold 154 is coupled to the
housing
102 and is in fluid communication with each heat transfer tube 112 of the top
tube
bank 116 and each heat transfer tube 112 of the first intermediate tube bank
120.
A respective fluid line 158 extends from the first end 306 of a respective
heat
transfer tube 112 of the top tube bank 116 to the tube inlet manifold 154. A
respective fluid line 160 also extends from the first end 306 of a respective
heat
transfer tube 112 of the first intermediate tube bank 120 to the tube inlet
manifold
154.
[0039] The heat exchanger 100 also includes a tube discharge manifold 156
for receiving cooling fluid discharged from each of heat transfer tube 112 of
the
sixth intermediate tube bank 130, and from each of heat transfer tube 112 of
the
bottom tube bank 118. The tube discharge manifold 156 is coupled to the
housing
102 and is in fluid communication with each heat transfer tube 112 of the
sixth
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intermediate tube bank 130, and each heat transfer tube 112 of the bottom tube
bank 118. A respective fluid line 162 extends from the first end 306 of a
respective
heat transfer tube 112 of the sixth intermediate tube bank 130 to the tube
discharge manifold 156. A respective fluid line 164 also extends from the
first end
306 of a respective heat transfer tube 112 of the bottom tube bank 118 to the
tube
discharge manifold 156.
[0040] The cooling fluid may be any suitable fluid that transfers heat
from
bulk solids 110 that flow between adjacent heat transfer tubes 112, for
example,
water or thermal oil.
[0041] The heat transfer tubes 112 of the top tube bank 116, the second
intermediate tube bank 122, the fourth intermediate tube bank 126, and the
sixth
intermediate tube bank 130 are arranged in columns and in fluid communication
with each other in a serpentine manner. A respective fluid line 166 extends
from
the second end 308 of a respective heat transfer tube 112 of the top tube bank
116
to the second end 308 of a respective heat transfer tube 112 of the second
intermediate tube bank 122. Similarly, a respective fluid line 168 extends
from the
first end 306 of a respective heat transfer tube 112 of the second
intermediate tube
bank 122 to the first end 306 of a respective heat transfer tube 112 of the
fourth
intermediate tube bank 126, and a respective fluid line 170 extends from the
second end 308 of a respective heat transfer tube 112 of the fourth
intermediate
tube bank 126 to the second end 308 of a respective heat transfer tube 112 of
the
sixth intermediate tube bank 130.
[0042] The heat transfer tubes 112 of the first intermediate tube bank
120,
the third intermediate tube bank 124, the fifth intermediate tube bank 128,
and the
bottom tube bank 118 are also arranged in columns and in fluid communication
with each other in a serpentine manner. A respective fluid line 172 extends
from
the second end 308 of a respective heat transfer tube 112 of the first
intermediate
tube bank 120 to the second end 308 of a respective heat transfer tube 112 of
the
third intermediate tube bank 124. Similarly, a respective fluid line 174
extends
from the first end 306 of a respective heat transfer tube 112 of the third
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intermediate tube bank 124 to the first end 306 of a respective heat transfer
tube
112 of the fifth intermediate tube bank 128, and a respective fluid line 176
extends
from the second end 308 of a respective heat transfer tube 112 of the fifth
intermediate tube bank 128 to the second end 308 of a respective heat transfer
tube 112 of the bottom tube bank 118.
[0043] Referring to FIG. 5, a side view of a portion of the heat
exchanger
100 of FIG. 1 is shown, in which a first end 306 of a heat transfer tube 112
of the
top tube bank 116 is coupled to an end 502 of a fluid line 158 by a seal 500.
As
shown in FIG. 5, the first end 306 of the heat transfer tube 112 passes
through an
opening in the first side wall 302 of the housing 102 and extends
therethrough.
The seal 500 facilitates movement of the heat transfer tube 112 within the
housing
102 when cooling fluid flows from the respective fluid line 158 into the heat
transfer
tube 112 under high pressure.
[0044] Referring to FIG. 6, an exploded perspective view of an example of
the
seal 500 is shown. The seal 500 includes a high temperature gasket 602, a
packing
collar 604, a high temperature packing 606, a sealing washer 608, a first
backing
washer 610, a compression spring 612, and a second backing washer 614. The
high temperature gasket 602 forms a seal against the first sidewall 302 of the
housing 102 of the heat exchanger 100 to inhibit any bulk solids 110 from
being
discharged from the housing 102 through a gap (not shown) between the heat
transfer tube 112 and the opening in the first sidewall 302 through which the
end
306 of the heat transfer tubes 112 passes through. The high temperature
packing
606 seals against an outer surface of the heat transfer tube 112 to also
inhibit any
bulk solids 110 from discharging from the housing 102 through the gap between
the heat transfer tube 112 and the opening in the first sidewall 302 of the
housing
102. The sealing washer 608 holds the high temperature packing 606 in place
and
ensures that the heat transfer tube 112 is centered in the packing collar 604.
The
first backing washer 610 transfers pressure from the compression spring 612 to
the
packing collar 604, and in turn to the high temperature gasket 602 and the
first
sidewall 302, as cooling fluid flows through the heat transfer tube 112. The
second
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backing washer 614 acts as a backing for the compression spring 612 against
the
respective fluid line 158.
[0045] The seal 500 is a leak resistant seal between the first end 306 of
a
heat transfer tube 112 and a respective fluid line 158 to inhibit leakage when
a
cooling fluid flows either into or from a first end 306 of the heat transfer
tube 112.
[0046] In the example shown in FIG. 1 and FIG. 2, the first end 306 of
each
heat transfer tube 112 of the top tube bank 116 is coupled to an end 502 of a
respective fluid line 158 by a seal 500. The second end 308 of each heat
transfer
tube 112 of the top tube bank 116 is also coupled to a second end of a
respective
fluid line 158 by a seal 500. Similarly, the first end 306 of each heat
transfer tube
112 of the tube banks 118, 120, 122, 124, 126, 128, and 130 are coupled to a
first
end 502 of the respective fluid lines 164, 160, 168, 174, 162 by a seal 500.
Also,
the second end 308 of each heat transfer tube 112 of the tube banks 118, 120,
122, 124, 126, 128, 130 are coupled to a second end of the respective fluid
lines
176, 166, 172, and 170 by a seal 500.
[0047] The flow of cooling fluid through the tube stack 114 will now be
described with reference to FIG. 1 and FIG. 2. In operation, cooling fluid
flows from
the tube inlet manifold 154 to the tube discharge manifold 156 in a serpentine
manner such that the cooling fluid flows from the tube inlet manifold 154,
into the
respective fluid lines 158, 160, through the heat transfer tubes 112 of the
top tube
bank 116 and the first intermediate tube bank 120, into the respective fluid
lines
166, 172, through the heat transfer tubes 112 of the second intermediate tube
bank 122 and the third intermediate tube bank 124, and into the respective
fluid
lines 168, 174. The cooling fluid then flows through the het transfer tubes
112 of
the fourth intermediate tube bank 126 and the fifth intermediate tube bank
128,
into the respective fluid lines 170, 176, through the heat transfer tubes 112
of the
sixth intermediate tube bank 130 and the bottom tube bank 118, into the
respective fluid lines 162, 164, and into the tube discharge manifold 156.
[0048] Although the flow of cooling fluid has been described herein as
flowing
in a downward direction through the tube stack 114, in an alternative
embodiment,
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the tube inlet manifold 154 may be a tube discharge manifold, the tube
discharge
manifold 156 may be a tube inlet manifold, and the direction of flow of the
cooling
fluid through the tube stack 114 and the heat transfer tubes 112 may be in an
opposite direction to that described such that the cooling fluid flows
upwardly
through the tube stack 114.
[0049] Referring to FIG. 7, a top view of the top assembly bank 138 of
the
heat exchanger 100 of FIG. 1 is shown. Each high temperature heat transfer
plate
assembly 134 of the top assembly bank 138 extends the width of the housing 102
between the first side wall 302 of the housing 102 and the opposing second
side
wall 304 of housing 102. The high temperature heat transfer plate assemblies
134
are arranged generally parallel to each other with spaces between adjacent
high
temperature heat transfer plate assemblies 134. Each space between adjacent
high
temperature heat transfer plate assemblies 134 defines a passageway 702 for
bulk
solids 110 to flow through. Optionally, insulation 704 may be disposed between
a
third side wall 314 of the housing 102 and the high temperature heat transfer
plate
assembly 134 located adjacent to the third side wall 314. Insulation 704 may
also
be disposed between the fourth side wall 316, and the high temperature heat
transfer plate assembly 134 located adjacent to or near the fourth sidewall
316.
The insulation 704 may be a ceramic fiber sheet of suitable thickness that
inhibits
the flow of bulk solids 110 in the space between the third side wall 314 and
the
adjacent high temperature heat transfer plate assembly 134, and the space
between the fourth side wall 316 and the adjacent high temperature heat
transfer
plate assembly 134, respectively.
[0050] Alternatively, a high temperature heat resistant lining 312 as
shown in
FIG. 3 and described above may be disposed between the third side wall 314 of
the
housing 102 and the high temperature heat transfer plate assembly 134 located
adjacent to or near the third side wall 314, and the water-skin jacket 318 may
be
disposed on the outer surface of the third side wall 314. The high temperature
heat
resistant lining 312 may also be disposed between the fourth side wall 316 and
the
high temperature heat transfer plate assembly 134 located adjacent to or near
the
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fourth sidewall 316 and the water-skin jacket 318 may also be disposed on the
outer surface of the fourth side wall 316.
[0051] The bottom assembly bank 140 and the first and second intermediate
assembly banks 142, 144 have a similar configuration as the top assembly bank
138.
[0052] The four assembly banks 138, 140, 142, and 144 of high temperature
heat transfer plate assemblies 134 may be vertically aligned in columns in the
housing 102 such that the passageways 702 extend through the entire assembly
stack 136. Alternatively, the high temperature heat transfer plate assemblies
134
in the four assembly banks 138, 140, 142, and 144 may be arranged such that
the
high temperature heat transfer plate assemblies 134 are horizontally offset
from
one another.
[0053] A perspective view of an example of a high temperature heat
transfer
plate assembly 134 is shown in FIG. 8. The high temperature heat transfer
plate
assembly 134 includes a heat transfer plate 802, a first fluid conduit 804,
and a
second fluid conduit 806, and a pipe 808. The term pipe is utilized herein to
refer
to a conduit through which fluid may flow. The pipe 808 is not limited to a
cylindrical pipe and may be any other suitable shape to facilitate fluid flow
therethrough.
[0054] The heat transfer plate 802 includes a pair of metal sheets 810.
The
sheets 810 may be made from stainless steel, such as 316L stainless steel. The
two sheets of the pair of sheets 810 are arranged generally parallel to each
other.
The two sheets are welded together at locations on each sheet and also seam
welded along the bottom edges of the two sheets. After the two sheets 810 are
welded together, the sheets are inflated such that generally circular
depressions
812 are formed on each sheet. The generally circular depressions 812 are
distributed throughout each sheet and are located at complementary locations
on
each sheet such that the generally circular depressions 812 on one of the
sheets
are generally aligned with the depressions 812 on the other of the sheets.
When
CA 02857852 2014-07-25
the sheets 810 are inflated, spaces are provided between the sheets 810 in
areas
where the sheets 810 are not welded together.
[0055] The first fluid conduit 804 extends along a first side edge 814 of
the
heat transfer plate 802, at least between a top end 816 and a bottom end 818
of
the heat transfer plate 802. The first fluid conduit 804 is welded to the
first side
edge 814 of each of the sheets 810. The second fluid conduit 806 extends along
an
opposing second side edge 820 of the heat transfer plate 802, at least between
the
top end 816 and the bottom end 818 of the heat transfer plate 802. The second
fluid conduit 806 is welded to the second side edge 820 of each of the sheets
810.
[0056] The pipe 808 extends along the top end 816 of the heat transfer
plate
802. A first end 822 of the pipe 808 is in fluid communication with the first
fluid
conduit 804. The pipe 808 passes through the second fluid conduit 806. The
pipe
808 may be in fluid communication with a top portion 910 (shown in FIG. 9) of
the
second fluid conduit 806. A second end 824 of the pipe 808 extends from the
second fluid conduit 806 to provide a cooling fluid inlet. The pipe 808 is
welded to
the top edge of each of the sheets 810. The pipe 808 may have a diameter that
is
greater than or equal to the thickness of the heat transfer plate 802.
[0057] The high temperature heat transfer plate assembly 134 also
includes a
cooling fluid outlet 826. The cooling fluid outlet 826 extends substantially
perpendicular to and away from the second fluid conduit 806. The cooling fluid
outlet 826 is in fluid communication with the second fluid conduit 806.
[0058] In the example embodiment shown in FIG. 8, the cooling fluid
outlet
826 is located near the bottom end 818 of the heat transfer plate 802.
Alternatively, the cooling fluid outlet 826 may be located any suitable
distance from
the bottom end 818 of the heat transfer plate 802. For example, the cooling
fluid
outlet 826 may be located near the middle of the second fluid conduit 806.
[0059] The first fluid conduit 804 and the second fluid conduit 806 have
diameters that are larger than the diameter of the pipe 808. When the high
temperature heat transfer plate assemblies 134 are arranged in an assembly
bank,
16
CA 02857852 2014-07-25
the first fluid conduits 804 of adjacent high temperature heat transfer plate
assemblies 134 abut each other and the second fluid conduits 806 of adjacent
high
temperature plate assemblies 134 abut each other, as shown in FIG. 7. The
diameters of the first and second fluid conduits 804, 806 may be larger than
the
diameter of the pipe 808 to space apart the high temperature heat transfer
plates
802 of adjacent high temperature heat transfer plate assemblies 134 when the
high
temperature heat transfer plate assemblies 134 are arranged in a bank.
Alternatively, the high temperature heat transfer plate assemblies 134 may be
arranged in an assembly bank such that the first fluid conduits 804 of
adjacent heat
transfer plate assemblies 134 are horizontally offset. For example, the first
fluid
conduits 804 of the first, third, fifth, seventh, ninth, and eleventh high
temperature
heat transfer plate assemblies 134 may be horizontally offset from the first
fluid
conduits 804 of the second, fourth, sixth, eighth, and tenth high temperature
heat
transfer plate assemblies 134 such that the first fluid conduits 804 of the
first,
third, fifth, seventh, ninth, and eleventh high temperature heat transfer
plate
assemblies 134 are not horizontally aligned with the first fluid conduits 804
of the
second, fourth, sixth, eighth, and tenth high temperature heat transfer plate
assemblies 134.
[0060] When the four assembly banks 138, 140, 142, and 144 are arranged
in an assembly stack 136, the first fluid conduits 804 of one assembly bank
may be
aligned with the first fluid conduits 804 of the assembly bank that is
directly below
such that the first fluid conduits 804 of the lower assembly bank support the
first
fluid conduits 804 of the upper assembly bank. Similarly, the second fluid
conduits
806 of the lower assembly bank support the second fluid conduits 806 of the
upper
assembly bank. Thus, a respective first fluid conduit 804 of a high
temperature
heat transfer plate assembly 134 of the top assembly bank 138 is disposed on a
respective first fluid conduit 804 of a high temperature heat transfer plate
assembly
134 of the first intermediate assembly bank 142, and a respective second fluid
conduit 806 of a high temperature heat transfer plate assembly 134 of the top
assembly bank 138 is disposed on a respective second fluid conduit 806 of a
high
temperature heat transfer plate assembly 134 of the first intermediate
assembly
bank 142. Similarly, a respective first fluid conduit 804 of a high
temperature heat
17
CA 02857852 2014-07-25
transfer plate assembly 134 of the first intermediate assembly bank 142 is
disposed
on a respective first fluid conduit 804 of a high temperature heat transfer
plate
assembly 134 of the second intermediate assembly bank 144, and a respective
second fluid conduit 806 of a high temperature heat transfer plate assembly
134 of
the first intermediate assembly bank 142 is disposed on a respective second
fluid
conduit 806 of a high temperature heat transfer plate assembly 134 of the
second
intermediate assembly bank 144.
[0061] Similarly, a respective first fluid conduit 804 of a high
temperature
heat transfer plate assembly 134 of the second intermediate assembly bank 144
is
disposed on a respective first fluid conduit 804 of a high temperature heat
transfer
plate assembly 134 of the bottom assembly bank 140, and a respective second
fluid
conduit 806 of a high temperature heat transfer plate assembly 134 of the
second
intermediate assembly bank 144 is disposed on a respective second fluid
conduit
806 of a high temperature heat transfer plate assembly 134 of the bottom
assembly bank 140.
[0062] Referring to FIG. 9, a sectional view of the high temperature heat
transfer plate assembly 134 of FIG. 8 is shown. The first fluid conduit 804
includes
openings 902 into the heat transfer plate 802. The openings 902 are
distributed
along the first fluid conduit 804 at the first side 814 of the high
temperature heat
transfer plate 802. The openings 902 may be unevenly distributed such that the
openings 902 are more closely spaced near the top of the first fluid conduit
804.
Alternatively, the openings 902 may be larger near the top of the first fluid
conduit
804. The second fluid conduit 806 includes openings 904 into the high
temperature
heat transfer plate 802. The openings 904 are distributed along the second
fluid
conduit 806 at the second side 820 of the heat transfer plate 802. The
openings
904 may be unevenly distributed such that the openings 904 are more closely
spaced near the top of the second fluid conduit 806. Alternatively, the
openings
904 may be larger near the top of the second fluid conduit 806. The pipe 808
also
includes an opening 908 to a top portion 910 of the second fluid conduit 806
to
provide cooling fluid to the top portion 910 of the second fluid conduit 806.
18
CA 02857852 2014-07-25
[0063] The cooling fluid enters the top portion 910 of the second fluid
conduit
806 through opening 908. The cooling fluid also enters the top portion 912 of
the
first fluid conduit 804. The top portion 910 of the second fluid conduit 806
and the
top portion 912 of the first fluid conduit 804 may be sized to inhibit
overheating of
the top portions 910, 912. Thus, the top portions 910, 912 of the first and
second
fluid conduits 804, 806 are short enough to facilitate fluid flow and cooling
of the
top portions 910, 912. Additionally, fluid may flow through the top portions
910,
912 of the first and second fluid conduits 804, 806 to further cool the top
portions
910, 912. To facilitate flow of cooling fluid, the outside diameter of the
pipe 808 is
sufficiently less than the inside diameter of the second fluid conduit 806 for
fluid to
flow from the top portion 910 into a lower portion of the second fluid conduit
806.
With sufficient fluid flow, the top portions 910, 912 may be longer and
spacing
between the assembly banks 138, 140, 142, 144 that are arranged in the
assembly
stack 136 may be increased.
[0064] Referring again to FIG. 1 and FIG. 2, the heat exchanger 100 also
includes a fluid inlet manifold 178 for providing cooling fluid into each high
temperature heat transfer plate assembly 134 of the top assembly bank 138. The
heat exchanger 100 also includes a fluid discharge manifold 180 for receiving
cooling fluid discharged from each high temperature heat transfer plate
assembly
134 of the bottom assembly bank 140. The fluid inlet manifold 178 is coupled
to
the housing 102 and is in fluid communication with each high temperature heat
transfer plate assembly 134 of the top assembly bank 138. A respective fluid
line
182 extends from each high temperature heat transfer plate assembly 134 of the
top assembly bank 138 to the first fluid inlet manifold 178. The fluid
discharge
manifold 180 is coupled to the housing 102 and is in fluid communication with
each
high temperature heat transfer plate assembly 134 of the bottom assembly bank
140. A respective fluid line 184 extends from each high temperature heat
transfer
plate assembly 134 of the bottom assembly bank 140 to the first fluid
discharge
manifold 180. The cooling fluid may be any suitable fluid that transfers heat
from
bulk solids 110 that flow between adjacent high temperature heat transfer
plate
assemblies 134, for example water or thermal oil.
19
CA 02857852 2014-07-25
[0065] In the example of FIG. 1 and FIG. 2, the high temperature heat
transfer plate assemblies 134 of the top assembly bank 138, the bottom
assembly
bank 140, and the two intermediate assembly banks 142, 144 are arranged in
columns. The high temperature heat transfer plate assemblies 134 of each
column
are in fluid connection with each other. For example, a respective fluid line
186
extends from each high temperature heat transfer plate assembly 134 of the top
assembly bank 138 to a respective heat transfer plate assembly 134 of the
first
intermediate assembly bank 142 of the same column. A respective fluid line 188
extends from each high temperature heat transfer plate assembly 134 of the
first
intermediate assembly bank 142 to a respective high temperature heat transfer
plate assembly 134 of the second intermediate assembly bank 144 of the same
column. A respective fluid line 190 extends from each high temperature heat
transfer plate assembly 134 of the second intermediate assembly bank 144 to a
respective high temperature heat transfer plate assembly 134 of the bottom
assembly bank 140 of the same column.
[0066] The flow of cooling fluid through the assembly stack 136 will now
be
described with reference to FIG. 1, FIG. 8, and FIG. 9. The flow of the
cooling fluid
through a high temperature heat transfer plate assembly 134 is illustrated by
the
arrows in FIG. 9. In operation, cooling fluid flows from the fluid inlet
manifold 178
through the respective fluid lines 182 into the respective pipes 808 of the
high
temperature heat transfer plate assemblies 134 of the top assembly bank 138.
For
the purposes of this example, the flow of cooling fluid through one of the
high
temperature heat transfer plate assemblies 134 will be described with
reference to
FIG. 9.
[0067] The cooling fluid flows through the pipe 808 of the high
temperature
heat transfer plate assembly 134 into the first fluid conduit 804. Cooling
fluid also
flows from the pipe 808, through the opening 908, and into the top portion 910
of
the second fluid conduit 806. From the first fluid conduit 804, the cooling
fluid
flows into the heat transfer plate 802 through the openings 902. The cooling
fluid
flows through the heat transfer plate 802 into the second fluid conduit 806,
through
the openings 904 in the second fluid conduit 806. The generally circular
CA 02857852 2014-07-25
depressions 812 distributed throughout the heat transfer plate 802 facilitate
the
flow of the cooling fluid throughout the heat transfer plate 802. The cooling
fluid
then flows from the second fluid conduit 806 into the cooling fluid outlet
826. The
cooling fluid that flows through the assembly stack 136 may be the same
cooling
fluid that flows though tube stack 114. Alternatively, the cooling fluid that
flows
through the high temperature assembly stack 136 may be a different cooling
fluid
than the cooling fluid that flows through tube stack 114.
[0068] Referring again to FIG. 1, FIG. 8, and FIG. 9, the cooling fluid
flows
from the cooling fluid outlet 826 of each high temperature heat transfer plate
assembly 134 of the top assembly bank 138, through the respective fluid lines
186,
and into the respective pipes 808 of the heat transfer plate assemblies 134 of
the
first intermediate assembly bank 142. The cooling fluid flows through each
high
temperature heat transfer plate assembly 134 of the first intermediate
assembly
bank 142 in a similar manner as described above.
[0069] The cooling fluid then flows from the cooling fluid outlet 826 of
the
high temperature heat transfer plate assemblies 134 of the first intermediate
high
temperature heat transfer plate assembly bank 142, through the respective
fluid
lines 188, and into the respective pipes 808 of the high temperature heat
transfer
plate assemblies 134 of the second intermediate bank 144. The cooling fluid
flows
through each high temperature heat transfer plate assembly 134 of the second
intermediate bank 144 in a similar manner as described above.
[0070] The cooling fluid then flows from the cooling fluid outlet 826 of
the
high temperature heat transfer plate assemblies 134 of the second intermediate
assembly bank 144 through the respective fluid lines 190, and into the
respective
pipes 808 of the high temperature heat transfer plate assemblies 134 of the
bottom
assembly bank 140. The cooling fluid flows through each high temperature heat
transfer plate assembly 134 of the bottom assembly bank 140 in a similar
manner
as described above.
21
CA 02857852 2014-07-25
[0071] The cooling fluid flows from the cooling fluid outlet 826 of each
high
temperature heat transfer plate assembly 134 of the bottom assembly bank 140
through the respective fluid lines 184, and into the fluid discharge manifold
180.
[0072] Although the flow of cooling fluid has been described herein as
flowing
in a downward direction through the assembly stack 136, in an alternative
embodiment the fluid inlet manifold 178 may be a fluid discharge manifold, the
fluid
discharge manifold 180 may be a fluid inlet manifold, and the direction of
flow of
cooling fluid through the assembly stack 136 and the high temperature heat
transfer plate assemblies 134 may be in an opposite direction to that
described
such that the cooling fluid flows upwardly through the assembly stack 136.
[0073] Referring to FIG. 10, a top view of the bank 148 of the heat
exchanger
100 of FIG. 1 is shown. Each low temperature heat transfer plate assembly 146
of
the bank 148 extends the width of the housing 102 between the first side wall
302
of the housing 102 and the opposing second side wall 304 of the housing 102.
The
low temperature heat transfer plate assemblies 146 are arranged generally
parallel
to each other with spaces between adjacent low temperature heat transfer plate
assemblies 146. Each space between adjacent low temperature heat transfer
plate
assemblies 146 defines a passageway 1002 for bulk solids 110 to flow through.
[0074] A sectional view of an example of a low temperature heat transfer
plate assembly 146 is shown in FIG. 11. The low temperature heat transfer
plate
assembly 146 includes a pair of metal sheets 1102, a fluid inlet 1104, and a
fluid
outlet 1106. The sheets 1102 may be made from stainless steel, such as 316L
stainless steel. Each sheet 1102 includes a top edge 1108, a bottom edge 1110,
a
front side edge 1112, and an opposing rear side edge 1114.
[0075] The low temperature heat transfer plate assembly 146 may be
assembled by, for example, arranging the pair of sheets 1102 generally
parallel to
each other. The sheets are welded together at locations distributed over the
sheets
and are seam welded along the top edges 1108, the opposing rear side edges
1114,
and the bottom edges 1110 of the two sheets 1102. After the two sheets 1102
are
welded together, slots are cut for insertion of nozzles that are welded to the
sheets
22
CA 02857852 2014-07-25
and are utilized as a fluid inlet 1104 and a fluid outlet 1106. The sheets
1102 are
inflated utilizing the nozzles such that generally circular depressions 1116
are
formed on each sheet. The generally circular depressions 1116 are distributed
throughout each sheet and are located at complementary locations on each sheet
such that the depressions 1116 on one of the sheets are generally aligned with
the
depressions 1116 on the other of the sheets. When the sheets 1102 are
inflated,
spaces are provided between the sheets 1102 in areas where the sheets 1102 are
not welded together to facilitate fluid flow through the sheets 1102.
[0076] The fluid inlet 1104 extends from the front side edge 1112 of the
sheets 1102 at a location near the top edge 1108 of the sheets 1102. The fluid
outlet 1106 extends the front side edge 1112 of the sheets 1102 at a location
near
the bottom edge 1110 of the sheets 1102.
[0077] Referring again to FIG. 1 and FIG. 2, the heat exchanger 100 also
includes an inlet manifold 192 for providing cooling fluid into each low
temperature
heat transfer plate assembly 146 of the bank 148 and a discharge manifold 194
for
receiving cooling fluid discharged from each low temperature heat transfer
plate
assembly 146 of the bank 148. The inlet manifold 192 is coupled to the housing
102 and is in fluid communication with each low temperature heat transfer
plate
assembly 146 of the bank 148. A respective fluid line 196 extends from the
inlet
manifold 192 to a fluid inlet 1104 of each low temperature heat transfer plate
assembly 146 of the bank 148. A respective fluid line 198 also extends from
the
discharge manifold 194 to a cooling fluid outlet 1106 of each heat transfer
plate
assembly 146 of the bank 148 as described in further detail below with
reference to
FIG. 11.
[0078] The flow of cooling fluid through the bank 148 will now be
described
with reference to FIG. 1, FIG. 2, and FIG. 11. The flow of the cooling fluid
through
a low temperature heat transfer plate assembly 146 is illustrated by the
arrows in
FIG. 11. In operation, cooling fluid flows from the inlet manifold 192 through
the
respective fluid lines 196, through the fluid inlet 1104 and into each low
temperature heat transfer plate assemblies 146 of the bank 148. The cooling
fluid
23
CA 02857852 2014-07-25
then flows through each low temperature heat transfer plate assembly 146,
through
the fluid outlet 1106, through the respective fluid lines 198, and into the
discharge
manifold 194.
[0079] In an alternative embodiment, the direction of flow of cooling
fluid
through each low temperature heat transfer plate assembly 146 may be in an
opposite direction to that described such that the cooling fluid flows from
the
discharge manifold 194, through the respective fluid lines 198, into the fluid
outlets
1106, through each low temperature heat transfer plate assembly 146, into the
fluid inlets 1104, through the respective fluid lines 196, and back into the
inlet
manifold 192.
[0080] In the example shown in FIG. 1 and FIG. 2, the eight tube banks
116,
118, 120, 122, 124, 126, 128, 130, the four assembly banks 138, 140, 142, 144,
and the single bank 148 are arranged in the housing 102 such that the
passageways 310, 702, 1002 are aligned and extend through the entire tube
stack
114, the entire assembly stack 136, and the bank 148 to facilitate the flow of
bulk
solids 110 through the heat exchanger 100 from the inlet 108 to the outlet.
[0081] The operation of the heat exchanger 100 will now be described with
reference to FIG. 1. When bulk solids 110 that have a starting temperature in
the
range of, for example, about 4000C to about 24000C are fed into the housing
102,
through the inlet 108, the bulk solids 110 flow downwardly as a result of the
force
of gravity from the inlet 108 into the hopper 132. The hopper 132 facilitates
distribution of the bulk solids 110 into the top tube bank 118 as described
above.
The bulk solids 110 flow through passageways 310, and bulk solids 110 that
contact the heat transfer tubes 112 are deflected into the passageways 310.
[0082] As the bulk solids 110 flow through the passageways 310, the bulk
solids 110 are cooled to a first intermediate temperature as the heat from the
bulk
solids 110 is transferred to the heat transfer tubes 112 and to the cooling
fluid.
The bulk solids may be cooled to a first intermediate temperature of, for
example,
about 7500C. The cooling fluid that flows through the heat transfer tubes 112
indirectly cools bulk solids 110 to the first intermediate temperature.
24
CA 02857852 2014-07-25
[0083] After initial cooling of the bulk solids 110 to the first
intermediate
temperature by the heat transfer tubes 112, the bulk solids 110 that flow
through
passageways 310 flow towards the passageways 702. Bulk solids 110 that contact
the high temperature heat transfer plate assemblies 134 are deflected into the
passageways 702.
[0084] As the bulk solids 110 that have the first intermediate
temperature
flow through passageways 702, the bulk solids 110 are further cooled to a
second
intermediate temperature of, for example, about 4000C. The cooling fluid that
flows through the high temperature heat transfer plate assemblies 134
indirectly
cools bulk solids 110 to the second intermediate temperature.
[0085] After cooling of the bulk solids 110 to the second intermediate
temperature by the high temperature heat transfer plate assemblies 134, the
bulk
solids 110 that flow through passageways 702 flow towards the passageways
1002.
Bulk solids 110 that contact the low temperature heat transfer plate
assemblies 146
are deflected into the passageways 1002.
[0086] As the bulk solids 110 that have the second intermediate
temperature
flow through passageways 1002, the bulk solids 110 are further cooled to a
cooled
temperature of, for example 1000C. The cooling fluid that flows through the
low
temperature heat transfer plate assemblies 146 indirectly cools bulk solids
110 to
the resulting temperature.
[0087] The bulk solids 110 then flow from the passageways 1002, through
the
outlet, and into the discharge hopper 112, where the cooled bulk solids 110
are
discharged under a "choked" flow.
[0088] Although the heat exchanger 100 shown in FIG. 1 and 2 includes a
tube stack 114, an assembly stack 136, and a single bank 148, in an
alternative
embodiment the heat exchanger 100 may include a tube stack 114 and an
assembly stack 136. In this embodiment, the passageways 310 and 702 are
vertically aligned such that bulk solids 110 flow through the heat exchanger
100
from the inlet 108, through the passageways 310 and 702, to the outlet. When
CA 02857852 2014-07-25
bulk solids 110 that have a starting temperature in the range of, for example,
about
400 C to about 2400 C are fed into the housing 102, through the inlet 108,
the
bulk solids 110 flow through the passageways 310, and the bulk solids 110 are
cooled to an intermediate temperature as the heat from the bulk solids 110 is
transferred to the heat transfer tubes 112 and to the cooling fluid. After
initial
cooling of the bulk solids 110 to the intermediate temperature by the heat
transfer
tubes 112, the bulk solids 110 that flow through passageways 310 flow towards
the
passageways 702 and the bulk solids 110 that contact the high temperature heat
transfer plate assemblies 134 are deflected into the passageways 702. As the
bulk
solids 110 that have the first intermediate temperature flow through
passageways
702, the bulk solids 110 are further cooled to a resulting temperature of, for
example, about 400 C. The cooling fluid that flows through the high
temperature
heat transfer plate assemblies 134 indirectly cools bulk solids 110 to the
resulting
temperature. The bulk solids 110 then flow from the passageways 702, through
the outlet, and into the discharge hopper 112, where the cooled bulk solids
110 are
discharged under a "choked" flow.
[0089] In other embodiments, the heat exchanger 100 may include a tube
stack 114 and a single bank 148 or multiple banks of low temperature heat
transfer
plate assemblies 146. In these embodiments, the passageways 310 and 1002 are
vertically aligned such that bulk solids 110 flow through the heat exchanger
100
from the inlet 108, through the passageways 310 and 1002, to the outlet. When
bulk solids 110 that have a starting temperature in the range of, for example,
about
400 C to about 2400 C are fed into the housing 102, through the inlet 108,
the
bulk solids 110 flow through the passageways 310, and the bulk solids 110 are
cooled to an intermediate temperature as the heat from the bulk solids 110 is
transferred to the heat transfer tubes 112 and to the cooling fluid. After
initial
cooling of the bulk solids 110 to the intermediate temperature by the heat
transfer
tubes 112, the bulk solids 110 that flow through passageways 310 flow towards
the
passageways 1002. Bulk solids 110 that contact the low temperature heat
transfer
plate assemblies 146 are deflected into the passageways 1002. As the bulk
solids
110 that have the first intermediate temperature flow through passageways
1002,
the bulk solids 110 are further cooled to a resulting temperature of, for
example,
26
CA 02857852 2014-07-25
about 4000C. The cooling fluid that flows through the low temperature heat
transfer plate assemblies 146 indirectly cools bulk solids 110 to the
resulting
temperature. The bulk solids 110 then flow from the passageways 1002, through
the outlet, and into the discharge hopper 112, where the cooled bulk solids
110 are
discharged under a "choked" flow.
[0090] Advantageously, the heat transfer tubes of the heat exchanger cool
bulk solids having a starting, high temperature to an intermediate temperature
before the bulk solids are cooled by the heat transfer plates of the heat
exchanger
to a resulting, cooled temperature. The cooling of bulk solids to an
intermediate
temperature by heat transfer tubes described herein before cooling the bulk
solids
to a resulting, cooled temperature by the heat transfer plate assemblies
described
herein, increases the operational life of the heat transfer plates and the
heat
exchanger described herein.
[0091] The described embodiments are to be considered in all respects
only
as illustrative and not restrictive. The scope of the claims should not be
limited by
the preferred embodiments set forth in the examples, but should be given the
broadest interpretation consistent with the description as a whole. All
changes that
come with meaning and range of equivalency of the claims are to be embraced
within their scope.
=
27
