[0001] The present invention relates to a multi stage washing column. Moreover, the present
invention relates to a device for drying wetted material comprising a multi stage
washing column.
[0002] Wetted material pursuant to the present invention can be wetted paper from a paper
mill. Nevertheless, the present invention is not restricted to wetted paper as wetted
material. The wetted material also can be wetted malt, wetted food, or wetted paint.
The present invention will be described in the following with regard to wetted paper
as wetted material. Nevertheless, the multi stage washing column according to the
present invention can be used in a device for drying wetted paper, wetted paint, wetted
malt, wetted food, and so on. Thereby it is to be mentioned that the relevant temperatures
for drying paper (60 °C - 150 °C) are at an elevated temperature level compared to
the temperatures (10 °C to 70 °C) mentioned with regard to the process of drying wetted
malt.
[0003] In the paper industry multiple steam fed cylinders and/or one big cylinder - a so
called Yankee - are used as drying devices / drying chambers for drying paper from
typically 47% dry mass (DM) up to 93% dry mass. According to the state of the art
heat recovery is in place, recuperating the sensible heat in the moisturized drying
air coming from the drying chambers.
[0004] The process of drying wetted paper is very energy consuming. It is therefore an issue
to reduce the energy consumption required for drying wetted paper.
[0005] The object of the present invention is to provide a washing column which can be used
in a device for drying wetted material, wherein the washing column enables a more
efficient heat energy recovery and exhibits less liquid (water) consumption for recovering
the heat energy of gas exiting the device for drying wetted material.
[0006] This object is solved by a multi stage washing column exhibiting the features of
claim 1. Advantageous embodiments of the multi stage washing column are described
in the claims depending on claim 1.
[0007] Moreover, the object of the present invention is also solved by a device for drying
wetted material exhibiting the features of claim 5. Advantageous embodiments of the
device are described in the claims depending on claim 5.
[0008] In detail, the multi stage washing column according to the present invention comprises
a gas inlet for introducing a gas into the multi stage washing column, a gas outlet
for exiting the gas out of the multi stage washing column, a hot liquid inlet for
introducing liquid into the multi stage washing column, a cold liquid inlet for introducing
liquid into the multi stage washing column, and a liquid outlet for exiting the liquid
out of the multi stage washing column, wherein in a mounting position of the multi
stage washing column the cold liquid inlet is positioned above the hot liquid inlet.
[0009] In the mounting position of the multi stage washing column liquid introduced into
cold liquid inlet follows the gravitational force into the direction to the hot liquid
inlet.
[0010] In this description "fluidly connected" means in general that the described parts
are directly connected or indirectly connected with other parts in between. In any
case a fluid stream is possible between the described parts.
[0011] In this description "thermally connected" means in general that the described parts
are directly connected or indirectly connected with other parts in between. In any
case a transfer of thermal energy is possible between the described parts.
[0012] Gas in the meaning of the present invention can for example be humid air and/or a
mixture of air and steam. Liquid in the meaning of the present invention can for example
be water.
[0013] The multi stage washing column according to the present invention exhibits the advantage
that the thermal energy of the gas introduced into the multi stage washing column
can be more effectively extracted and therefore can be more effectively used by other
devices (for example for heating of a drying device, for heating of water, for heating
of a building and so on) which are fluidly and/or thermally connected with the multi
stage washing column. Especially when the temperature of the gas introduced in the
multi stage washing column exhibits a high temperature, for example in the range of
150°C, the thermal energy being the sum of sensible and latent heat of the gas can
be extracted by the multi stage washing column very effectively.
[0014] Gas introduced into the multi stage washing column exhibits a dew point which depends
on the temperature of the gas and the percentage of humidity of the gas which also
can be named the moisture content of the gas. Liquid exhibiting a temperature slightly
below the dew point of the gas introduced into the multi stage washing column can
be introduced into the multi stage washing column via the hot liquid inlet. Since
the humidity absorption capacity of gas and air, respectively, rises exponentially
with the temperature of the gas/air, a very high percentage of the humidity of the
gas/air condensates when the gas/air is cooled down by the liquid introduced into
the multi stage washing column via the hot liquid inlet. The liquid introduced into
the multi stage washing column via the hot liquid inlet is heated by the condensation
of the humidity of the gas/air and by heat transfer from the gas/air to the liquid.
For that reason the temperature of the liquid collected at a bottom of the multi stage
washing column is considerably high and therefore the heat energy of the liquid can
be very effectively used by other devices (e.g. a heat pump). The gas ascending inside
the multi stage washing column exhibits a reduced temperature, a reduced humidity
and therefore a reduced dew point. Liquid exhibiting a temperature slightly below
the reduced dew point of the gas ascended in the multi stage washing column can be
introduced into the multi stage washing column via the cold liquid inlet. Compared
to the amount of liquid introduced into the washing column via the hot liquid inlet
a reduced amount of liquid is introduced into the multi stage washing column via the
cold liquid inlet. This reduced amount of liquid is sufficient to condensate out a
further percentage of humidity out of the gas/air. Therefore, the liquid introduced
into the multi stage washing column via the cold liquid inlet only slightly cools
down the liquid collected at the bottom of the multi stage washing column.
[0015] Consequently, the thermal energy of the gas/air introduced into the multi stage washing
column can be extracted wherein at the same time the temperature of the liquid collected
inside the multi stage washing column at its bottom is only slightly below the dew
point of the gas introduced into the multi stage washing column. Therefore, the thermal
energy of the gas is transferable to other devices very effectively.
[0016] A correspondingly designed multi stage washing column can be named a 2-stage washing
column.
[0017] The humidity absorption capacity of the gas/air can also be named water vapor capacity
of the gas/air.
[0018] The multi stage washing column also can be named a multi stage heat recovery washing
column.
[0019] The hot liquid inlet can also be named a washing column hot liquid inlet or a first
liquid inlet or a first washing column liquid inlet or a hot water inlet.
[0020] The cold liquid inlet can also be named a washing column cold liquid inlet or a third
liquid inlet or a third washing column liquid inlet or a cold water inlet.
[0021] The liquid outlet can also be named a washing column liquid outlet or a water outlet
or a washing column water outlet. In the mounting position of the multi stage washing
column the liquid outlet is positioned underneath the hot liquid inlet.
[0022] The hot liquid inlet is adapted for introducing a liquid (preferably water) of a
first temperature into the washing column. The first temperature can preferably be
in the range of 65°C to 75°C.
[0023] The cold liquid inlet is adapted for introducing a liquid (preferably water) of a
third temperature into the washing column. The third temperature is lower than the
first temperature. The third temperature can preferably in the range of 10°C to 55°C.
[0024] Consequently, a temperature of the liquid introduced into the washing column via
the hot liquid inlet has to be higher than a temperature of the liquid introduced
into the washing column via the cold liquid inlet so that the multi stage washing
column can function in its designated manner.
[0025] The gas introduced into the multi stage washing column and exiting the multi stage
washing column can be a mixture of air (breathing air) and moisture, wherein the gas
exiting the multi stage washing column exhibits a lower percentage of absorbed humidity/water.
[0026] In the mounting position of the multi stage washing column the gas outlet is positioned
above the cold liquid inlet which is positioned above the hot liquid inlet which is
positioned above the gas inlet. Preferably, the liquid outlet is positioned underneath
the gas inlet.
[0027] The multi stage washing column preferably is designed in that way that in the mounting
position of the multi stage washing column the gas outlet is positioned above the
gas inlet.
[0028] Preferably, the multi stage washing column further comprises an intermediate temperature
liquid inlet, wherein the intermediate temperature liquid inlet is positioned between
the hot liquid inlet and the cold liquid inlet.
[0029] The correspondingly designed multi stage washing column exhibits the advantage that
thermal energy of hot gas (e.g. a mixture of hot air and steam) introduced into the
multi stage washing column via the gas inlet can be even more effectively extracted,
wherein the liquid/water collected at the bottom of the multi stage washing column
exhibits a higher temperature, and wherein the overall liquid consumption required
for cooling down the gas and for drying the gas is reduced. Since the liquid collected
at the bottom of the multi stage washing column exhibits a higher temperature, the
thermal energy of the liquid can be more effectively transferred to another device
(for example a transfer via a heat pump). A correspondingly designed multi stage washing
column can be named a 3-stage washing column.
[0030] Preferably, the multi stage washing column comprises a plurality of liquid inlets,
wherein in the mounting position of the multi stage washing column each liquid inlet
is arranged at a different vertical position of the multi stage washing column.
[0031] The multi stage washing column can exhibit four, five, six, or even more liquid inlets.
The number of liquid inlets, which is identical with the number of stages of the multi
stage washing column, is a function of the dew point of the incoming venting gas.
[0032] A liquid inlet of the multi stage washing column is adapted for introducing a liquid
exhibiting a temperature which is lower than a temperature of liquid introduced into
the multi stage washing column via a liquid inlet which is positioned vertically underneath
said liquid inlet. Therefore, the temperature of liquid introduced into the multi
stage washing column via the plurality of liquid inlets decreases with higher positioning
of the liquid inlets.
[0033] The object of the present invention is also solved by a device for drying wetted
material which comprises at least one drying device for accommodating the wetted material,
an above described multi stage washing column, and a heat pump, wherein the liquid
outlet of the multi stage washing column is fluidly connected with a first heat pump
liquid inlet and a first liquid outlet of the heat pump is fluidly connected with
the hot liquid inlet of the multi stage washing column. A second heat pump inlet is
fluidly connected with a with a hot fluid source, and a second heat pump outlet is
fluidly connected with a drying device gas inlet and a drying device outlet is fluidly
connected with the gas inlet of the multi stage washing column.
[0034] Due to the fluid connection of the multi stage washing column with the heat pump
a heat cycle between the washing column and the heat pump is realized. The heat cycle
is realized between the liquid outlet of the multi stage washing column, the first
heat pump liquid inlet, the first heat pump liquid outlet, and the hot liquid inlet
of the multi stage washing column. Thermal energy extracted from the water exiting
the multi stage washing column is transferred to the heat pump and thermal energy
extracted from the heat pump is transferred to the medium entering the heat pump via
the second heat pump inlet, so that the medium exiting the heat pump via the second
heat pump outlet can be used for drying the wetted material.
[0035] The wetted material preferably is wetted paper.
[0036] The drying device can comprise a drying chamber and/or can be named a drying chamber
and/or can be named a Yankee. Moreover, the drying device can comprise a plurality
of drying chambers and/or multiple drying cylinders.
[0037] The hot gas introduced into the drying device via the drying device gas inlet usually
is hot air and/or a mixture of hot air and moisture.
[0038] The first heat pump liquid inlet can also be named a first heat pump water inlet.
The first heat pump liquid outlet can also be named a first heat pump water outlet.
The second heat pump liquid inlet can also be named a second heat pump water inlet.
The second heat pump liquid outlet can also be named a second heat pump water outlet
or second heat pump steam outlet.
[0039] For example the hot fluid source can be a boiler for feeding hot water and/or hot
steam and/or hot air. The water/steam/air can preferably exhibit a temperature of
more than 105°C.
[0040] The gas/steam exiting the heat pump via the second heat pump outlet preferably exhibits
a pressure of three to four bar.
[0041] More preferably, the device for drying wetted material further comprises a compressor
arranged between the second heat pump outlet and the drying device gas inlet, wherein
a compressor inlet is fluidly connected with the second heat pump outlet and a compressor
outlet is fluidly connected with the drying device gas inlet.
[0042] By fluidly connecting the compressor with the second heat pump outlet the pressure
of the gas/air/steam exiting the heat pump via the second heat pump outlet can be
increased from approximately 3 to 4 bar up to approximately 8 to 9 bar which is more
suitable for drying device which can be realized as heating cylinders.
[0043] Preferably, the compressor is designed as a steam compressor.
[0044] More preferably, the device comprises the above described 3-stage washing column
exhibiting the intermediate temperature liquid inlet. The device further comprises
a heat exchanger, wherein a first heat exchanger liquid inlet is fluidly connected
with the first heat pump liquid outlet and the hot liquid inlet of the multi stage
washing column. A first heat exchanger liquid outlet is fluidly connected with the
intermediate temperature liquid inlet of the multi stage washing column, and a second
heat exchanger liquid inlet and a second heat exchanger liquid outlet are fluidly
connected with a heat energy consumer, so that thermal energy from the liquid introduced
into the heat exchanger via the first heat exchanger liquid inlet is transferable
to the heat energy consumer.
[0045] The heat energy consumer can be for example a process water tank and/or a space heating.
The heat exchanger can also be named a heat pump and a second heat pump, respectively.
[0046] Due to the fluid connection of the multi stage washing column with the heat exchanger
a heat cycle between the washing column and the heat exchanger is realized. The heat
cycle is realized between the liquid outlet of the multi stage washing column, the
first heat pump liquid inlet, the first heat pump liquid outlet, the first heat exchanger
liquid inlet, the first heat exchanger outlet and the intermediate temperature liquid
inlet of the multi stage washing column. Thermal energy extracted from the water exiting
the heat pump via the first heat pump liquid outlet is transferred to the heat exchanger
and thermal energy extracted from the heat exchanger is transferred to a medium (for
example water) circulating between the heat energy consumer (for example a process
water tank and/or a space heating) and the heat exchanger via the second heat exchanger
inlet and the second heat exchanger outlet.
[0047] A valve / flow adjuster can be arranged directly upstream of the first heat exchanger
liquid inlet and/or upstream of the intermediate temperature liquid inlet of the multi
stage washing column, so that a distribution of the amount of fluid flowing into the
heat exchanger and flowing into the multi stage washing column via the intermediate
temperature liquid inlet is adjustable.
[0048] More preferably, the device for drying wetted material is designed that way that
the cold liquid inlet of the multi stage washing column is fluidly connected with
a fresh water source.
[0049] By introducing fresh water into the multi stage washing column via the cold liquid
inlet the gas/air ascended inside the multi stage washing column can be further cooled
down and even more thermal energy of the gas/air can be extracted by condensation
of the humidity due to the further cooling by the fresh liquid / fresh water introduced
into the multi stage washing column via the cold liquid inlet. The amount of fresh
liquid / fresh water introduced into the multi stage washing column is smaller than
the amount of liquid/water introduced into the multi stage washing column via the
hot liquid inlet and the intermediate temperature liquid inlet, respectively.
[0050] Further advantages, details and features of the present invention are explained in
the description of the following embodiments, Thereby,
- figure 1:
- shows a schematic diagram of a device for drying wetted material according to a first
embodiment of the present invention, wherein the device comprises a multi stage washing
column according the first embodiment of the present invention; and
- figure 2:
- shows a schematic diagram of a device for drying wetted material according to a second
embodiment of the present invention, wherein the device comprises a multi stage washing
column according the second embodiment of the present invention.
[0051] In the following description same reference numerals describe same elements and same
features, respectively, so that a description of one element conducted with reference
to one figure is also valid for the other figures, so that repetition of the respective
feature is omitted.
[0052] Figure 1 shows a schematic diagram of a device 100 for drying wetted material WM
according to a first embodiment of the present invention. Wetted material WM in the
sense of the present invention can be wetted paper, wetted paint, wetted malt, or
wetted food, so that there is no restriction regarding the nature of the wetted material
WM. The present invention will be described in the following with regard to wetted
paper as wetted material WM to describe the functionality of the device 100 for drying
wetted material WM. Nevertheless, the device 100 for drying wetted material WM according
to the present invention can also be used for drying wetted paint, wetted malt and
wetted malt.
[0053] The device 100 for drying wetted material WM comprises at least one drying device
10 for accommodating the wetted paper WM, a multi stage washing column 20, and a heat
pump 30. A liquid outlet 26 of the multi stage washing column 20 is fluidly connected
with a first heat pump liquid inlet 31 and a first liquid outlet 32 of the heat pump
30 is fluidly connected with a hot liquid inlet 23 of the multi stage washing column
20. A second heat pump inlet 33 is fluidly connected with a hot fluid source which
e.g. can be a source for steam generation and/or air providing a fluid e.g. exhibiting
a temperature in the range of 105°C. A second heat pump outlet 34 is fluidly connected
with a drying device gas inlet 11 and a drying device outlet 12 is fluidly connected
with a gas inlet 21 of the multi stage washing column 20.
[0054] Due to the fluid connection of the multi stage washing column 20 with the heat pump
30 a heat cycle between the multi stage washing column 20 and the heat pump 30 is
realized. The heat cycle is realized by a circulating liquid which e.g. can be water.
The water circulates between the liquid outlet 26 of the multi stage washing column
20, the first heat pump liquid inlet 31, the first heat pump liquid outlet 32, and
the hot liquid inlet 23 of the multi stage washing column 20. Thermal energy extracted
from the water exiting the multi stage washing column 20 is transferred to the heat
pump 30 and thermal energy extracted from the heat pump 30 is transferred to the medium
(water/steam/air) entering the heat pump 30 via the second heat pump inlet 33, so
that the medium exiting the heat pump 30 via the second heat pump outlet 34 can be
used for drying the wetted paper. In the described embodiment the medium exiting the
heat pump 30 via the second heat pump outlet 34 preferably exhibits a temperature
in the range of 140°C to 150°C.
[0055] In the device 100 according to the first embodiment of the present invention the
pressure of the medium exiting the heat pump 30 via the second heat pump outlet 34
is in the range of 3 bar to 4 bar. The second heat pump outlet 34 is fluidly connected
with a low pressure fluid pipe 70. The low pressure fluid pipe 70 can be fluidly connected
with different thermal energy consumers of hot air / hot steam exhibiting a pressure
of 3 - 4 bar, wherein these thermal energy consumers are not shown in figure 1.
[0056] As can be seen from figure 1 the low pressure fluid pipe 70 is fluidly connected
with an intermediate pressure fluid pipe 80 via a compressor 50, which according to
the first embodiment of the present invention is realized as a steam compressor 50.
More precisely the low pressure fluid pipe 70 is fluidly connected with an inlet 51
of the compressor 50, and an outlet 52 of the compressor 50 is fluidly connected with
the intermediate pressure fluid pipe 80. The compressor 50 compresses the fluid (air
and/or steam) fed from the low pressure fluid pipe 70 in a pressure range between
8 bar and 10 bar. The intermediate pressure fluid pipe 80 is fluidly connected with
the inlet 11 of the drying device 10, so that the wetted paper WM inside the drying
device 10 is dried by the pressurized medium, which also can be named gas and/or air
and/or steam.
[0057] The mixture of air and steam exiting the drying device 10 via the outlet 12 of the
drying device 10 enters the multi stage washing column 20 via the gas inlet 21. The
mixture of air and steam exhibits a temperature in the range of 150°C and a dew point
in the range of 85°C. The temperature of the water injected into the multi stage washing
column 20 via the hot liquid inlet 23 exhibits a temperature in the range of 70°C.
[0058] Since the water injected via the hot liquid inlet 23 exhibits a lower temperature
than the mixture of air and steam injected via the gas inlet 21 into the multi stage
washing column 20, a very high percentage of the humidity of the air condensates when
the air is cooled down by the water introduced into the multi stage washing column
20 via the hot liquid inlet 21. The liquid introduced into the multi stage washing
column 20 via the hot liquid inlet 21 is heated by the condensation of the humidity
of the air and by heat transfer from the air to the water. For that reason the temperature
of the water collected at a bottom of the multi stage washing column 20 is considerably
high (in the range of 80°C) and therefore the heat energy of the water can be very
effectively used by the heat pump 30. Since the humidity absorption capacity of air
rises exponentially with the temperature of the air, a very high percentage of the
humidity is condensed out of the air in the first stage of the multi stage washing
column 20 by cooling down the air with water exhibiting a temperature which is slightly
below the dew point of the air injected via the gas inlet 21 of the multi stage washing
column 20.
[0059] The air ascending inside the multi stage washing column 20 exhibits a reduced temperature,
a reduced humidity and therefore a reduced dew point in the range of 65°C. Water exhibiting
a temperature below the reduced dew point of the air ascended in the multi stage washing
column 20 is introduced into the multi stage washing column 20 via the cold liquid
inlet 25. In the mounting position (shown in figure 1) of the multi stage washing
column 20 the cold liquid inlet 25 is positioned above the hot liquid inlet 23. Compared
to the amount of water introduced into the multi stage washing column 20 via the hot
liquid inlet 21 a reduced amount of water is introduced into the multi stage washing
column 20 via the cold liquid inlet 25. This reduced amount of water is sufficient
to condensate out a further percentage of humidity out of the air. Therefore, the
water introduced into the multi stage washing column 20 via the cold liquid inlet
25 only slightly cools down the water collected at the bottom of the multi stage washing
column 20.
[0060] The air exiting the multi stage washing column 20 via a gas outlet 22 exhibits a
temperature in the range of 20°C to 40°C, preferably 30°C.
[0061] Figure 2 shows a schematic diagram of a device 100 for drying wetted material WM
according to a second embodiment of the present invention. The device 100 according
to the second embodiment exhibits all components and features of the device 100 according
to the first embodiment. The device 100 according to the second embodiment further
comprises a multi stage washing column 20 wish is realized as a 3-stage washing column
20. The washing column 20 further comprises an intermediate temperature liquid inlet
24, wherein the intermediate temperature liquid inlet (24) is positioned between the
hot liquid inlet 23 and the cold liquid inlet 25.
[0062] The multi stage washing column 20 according to the second embodiment of the present
invention exhibits the advantage that thermal energy of air introduced into the multi
stage washing column 20 via the gas inlet 21 can be even more effectively extracted,
wherein the water collected at the bottom of the multi stage washing column exhibits
a higher temperature, and wherein the overall liquid consumption required for cooling
down the air and for drying the air is reduced. Since the water collected at the bottom
of the multi stage washing column 20 exhibits a higher temperature, the thermal energy
of the water can be more effectively transferred to a heat consumer 60.
[0063] The device 100 according to the second embodiment furthermore comprises a heat exchanger
40, wherein a first heat exchanger inlet 41 is fluidly connected with the first heat
pump liquid outlet 32 and the hot liquid inlet 23 of the multi stage washing column
20. A first heat exchanger liquid outlet 42 is fluidly connected with the intermediate
temperature liquid inlet 24 of the multi stage washing column 20, and a second heat
exchanger liquid inlet 43 and a second heat exchanger liquid outlet 44 are fluidly
connected with a heat energy consumer 60, so that thermal energy from the water introduced
into the heat exchanger 40 via the first heat exchanger liquid inlet 41 is transferable
to the heat energy consumer 60.
[0064] Due to the fluid connection of the multi stage washing column 20 with the heat exchanger
40 a heat cycle between the multi stage washing column 20 and the heat exchanger 40
is realized. The heat cycle is realized by circulating water circulating between the
liquid outlet 26 of the multi stage washing column 20, the first heat pump liquid
inlet 31, the first heat pump liquid outlet 32, the first heat exchanger liquid inlet
41, the first heat exchanger outlet 42 and the intermediate temperature liquid inlet
24 of the multi stage washing column 20. Thermal energy extracted from the water exiting
the heat pump 30 via the first heat pump liquid outlet 32 is transferred to the heat
exchanger 40 and thermal energy extracted from the heat exchanger 40 is transferred
to a medium (for example water) circulating between the heat energy consumer 60 (for
example a process water tank and/or a space heating) and the heat exchanger 40 via
the second heat exchanger inlet 43 and the second heat exchanger outlet 44.
[0065] The temperature of the water entering the heat exchanger via the first heat exchanger
inlet 41 can preferably be 70°C, and the temperature of the water exiting the heat
exchanger 40 via the first heat exchanger outlet 42 is preferably 55°C. The dew point
of the ascended air inside the multi stage washing column 20 in the area of the second
stage, i.e. in the area of the intermediate temperature liquid inlet 24 is in the
range of 60°C so that humidity is condensed out of this air by cooling it down with
water injected via the intermediate temperature liquid inlet 24.
[0066] The temperature of the water injected into the multi stage washing column 20 via
the cold liquid inlet 25 can preferably be 10°C. The dew point of the gas inside the
washing column 20 in the area of the third stage, i.e. in the area of the cold liquid
inlet 25 is approximately 40°C so that humidity is condensed out of this air by cooling
it down with water injected via the cold liquid inlet 25.
Reference numerals
[0067]
- 10
- drying device
- 11
- inlet (of the drying device)
- 12
- outlet (of the drying device)
- 20
- (multi stage) washing column
- 21
- (washing column) gas inlet
- 22
- (washing column) gas outlet
- 23
- (washing column) hot liquid inlet / first washing column liquid inlet
- 24
- intermediate temperature liquid inlet / second washing column liquid inlet
- 25
- (washing column) cold liquid inlet / third washing column liquid inlet
- 26
- (washing column) liquid outlet
- 30
- heat pump
- 31
- first heat pump liquid inlet
- 32
- first heat pump liquid outlet
- 33
- second heat pump inlet
- 34
- second heat pump outlet
- 40
- heat exchanger
- 41
- first heat exchanger liquid inlet
- 42
- first heat exchanger liquid outlet
- 43
- second heat exchanger liquid inlet
- 44
- second heat exchanger liquid outlet
- 50
- (steam) compressor
- 51
- inlet (of the compressor)
- 52
- outlet (of the compressor)
- 60
- heat consumer
- 70
- low pressure fluid pipe
- 80
- intermediate pressure fluid pipe
- WM
- wetted material / wetted paper
1. Multi stage washing column (20) with
- a gas inlet (21) for introducing a gas into the multi stage washing column (20),
- a gas outlet (22) for exiting the gas out of the multi stage washing column (20),
- a hot liquid inlet (23) for introducing liquid into the multi stage washing column
(20),
- a cold liquid inlet (25) for introducing liquid into the multi stage washing column
(20), and
- a liquid outlet (26) for exiting the liquid out of the multi stage washing column
(20),
wherein in a mounting position of the multi stage washing column (20) the cold liquid
inlet (25) is positioned above the hot liquid inlet (23).
2. Multi stage washing column (20) according to claim 1, characterized in that in the mounting position of the multi stage washing column (20) the gas outlet (22)
is positioned above the gas inlet (21).
3. Multi stage washing column (20) according to any of the preceding claims,
characterized by the following features:
- the multi stage washing column (20) further comprises an intermediate temperature
liquid inlet (24); and
- the intermediate temperature liquid inlet (24) is positioned between the hot liquid
inlet (23) and the cold liquid inlet (25).
4. Multi stage washing column (20) according to any of the preceding claims,
characterized by the following features:
- the multi stage washing column (20) comprises a plurality of liquid inlets (23,
24, 25); and
- in the mounting position of the multi stage washing column (20) each liquid inlet
(23, 24, 25) is arranged at a different vertical position of the multi stage washing
column (20).
5. Device (100) for drying wetted material (WM), comprising at least one drying device
(10) for accommodating the wetted material (WM), a multi stage washing column (20)
according to any of the preceding claims, and a heat pump (30), wherein
- the liquid outlet (26) of the multi stage washing column (20) is fluidly connected
with a first heat pump liquid inlet (31) and a first liquid outlet (32) of the heat
pump (30) is fluidly connected with the hot liquid inlet (23) of the multi stage washing
column (20);
- a second heat pump inlet (33) is fluidly connected with a with a hot fluid source;
and
- a second heat pump outlet (34) is fluidly connected with a drying device gas inlet
(11) and a drying device outlet (12) is fluidly connected with the gas inlet (21)
of the multi stage washing column (20).
6. Device (100) according to claim 5, characterized in that the device (100) further comprises a compressor (50) arranged between the second
heat pump outlet (34) and the drying device gas inlet (11), wherein a compressor inlet
(51) is fluidly connected with the second heat pump outlet (34) and a compressor outlet
(52) is fluidly connected with the drying device gas inlet (11).
7. Device (100) according to any of the claims 5 to 6, wherein the device (100) comprises
a multi stage washing column (20) according to claim 3,
characterized by the following features:
- the device (100) further comprises a heat exchanger (40);
- a first heat exchanger liquid inlet (41) is fluidly connected with the first heat
pump liquid outlet (32) and the hot liquid inlet (23) of the multi stage washing column
(20) ;
- a first heat exchanger liquid outlet (42) is fluidly connected with the intermediate
temperature liquid inlet (24) of the multi stage washing column (20); and
- a second heat exchanger liquid inlet (43) and a second heat exchanger liquid outlet
(44) are fluidly connected with a heat energy consumer (60), so that thermal energy
from the liquid introduced into the heat exchanger (40) via the first heat exchanger
liquid inlet (41) is transferable to the heat energy consumer (60).
8. Device (100) according to any of the claims 5 to 7, characterized in that the cold liquid inlet (25) of the multi stage washing column (20) is fluidly connected
with a fresh water source.