JP4751739B2 - Dehydration drying apparatus and dehydration drying method - Google Patents

Description

  The present invention relates to a dehydration drying apparatus and a dehydration drying method.

  As a device for separating the solid component contained in the slurry from the liquid portion, there is a dehydration drying device using a filter press device. In this dehydrating and drying apparatus, the slurry is carried into a filter chamber provided in the apparatus, and the slurry is filtered and dried to separate the solid component and the liquid component of the slurry.

  Generally, a polypropylene filter plate is used as the resin filter plate constituting the filter chamber, and the use condition is 90 ° C. For this reason, 90 ° C. hot water has been used as a heating medium for heating the slurry used in the filter press apparatus. In addition, direct heat exchange or indirect heat exchange using steam is often used as a method for producing the warm water.

  Moreover, the processing method which heats a slurry through a diaphragm using steam instead of warm water as said heating medium is also proposed (for example, refer patent document 1).

Japanese Patent No. 3040478

  In the dehydrating and drying apparatus using warm water described above, the necessary amount of hot water is calculated from the amount of water present in the piping in the dehydrating and drying apparatus and the amount of water circulating in the dehydrating and drying apparatus. However, it was difficult to control the amount of water during drying and before and after drying due to large variations in the amount of warm water.

  Accordingly, the present invention has been made in view of such problems, and an object thereof is to provide a new and improved dehydration drying apparatus and dehydration drying method that do not require a high-temperature heating medium or complicated control. There is.

  In order to solve the above-described problems, according to a first aspect of the present invention, there is provided a dehydrating and drying apparatus for filtering and drying slurry supplied to a filter chamber. A pair of diaphragms provided between the plates and substantially parallel to the filter plate, and a pair of filter cloths provided between the diaphragms and substantially parallel to the diaphragm, and the filter chamber contains the slurry. There is provided a dehydrating and drying apparatus in which a vacuum steam of 35 to 99 ° C. is supplied as a medium for heating the filter cake while being sucked in vacuum when the filter cake obtained by filtering is dried.

  In order to solve the above problems, according to a second aspect of the present invention, there is provided a dehydrating and drying apparatus for filtering and drying slurry supplied to a filter chamber, the filter chamber being opposed to the filter plate and the filter plate. And a diaphragm interposed between the diaphragm and the metal plate, and between the diaphragm and the metal plate, and between the diaphragm and the metal plate. The filter chamber includes a pair of substantially parallel filter cloths, and a vacuum chamber of 35 to 99 ° C. is used as a medium for heating the filter cake while being sucked in vacuum when the filter cake obtained by filtering the slurry is dried. Is provided.

  According to this structure, the 35-99 degreeC vacuum vapor | steam supplied in the filter chamber heats the filter cake obtained by filtering a slurry. As a result, the moisture contained in the filter cake can be removed and the filter cake can be dried. In addition, since vacuum vapor is directly used as a heating medium, the dehydrating and drying apparatus can be easily controlled.

  The dehydrating and drying apparatus may further include a filter press device that removes moisture from the slurry, and the filter chamber may be provided in the filter press device. According to this structure, a filter press apparatus dries, after filtering and pressing a slurry. As a result, a multistage treatment process for the slurry can be performed in the filter chamber provided in the filter press apparatus.

  The above dehydrating and drying apparatus may further include a separator that separates drain from steam supplied from the outside of the dehydrating and drying apparatus. According to such a configuration, the separator removes moisture contained in steam supplied from the outside. As a result, the steam supplied from the outside can be changed to vacuum steam.

  More specifically, the above vacuum steam is supplied with water to the superheated steam supplied from the outside of the dehydration drying device to reduce the temperature while removing the superheat to make the wet saturated steam. It is obtained by removing drain using

  The dehydrating and drying apparatus further includes an ejector and a water storage tank. The ejector uses the water stored in the water storage tank as a driving source, and the condensed water generated when the vacuum vapor passes through the filter chamber, drain, It is also possible to suck. According to this configuration, the ejector sucks the condensed water generated when the vacuum vapor passes through the filter chamber and the drain separated by the separator, using the water stored in the water storage tank as a drive source. When the ejector sucks the drain, the separator can be brought to atmospheric pressure or lower.

  Further, when the separator is reduced to atmospheric pressure or less by the ejector, the vacuum vapor passing through the separator is reduced due to the pressure change, and becomes a vacuum vapor having a predetermined temperature.

  The filter plate may be a polypropylene resin, and the metal plate may be a stainless steel plate. By using such a substance, heat can be efficiently transferred from the vacuum vapor as a heating medium.

  In order to solve the above problems, according to a third aspect of the present invention, there is provided a dehydration drying method for filtering and drying a slurry supplied to a filter chamber, wherein (a) a step of filtering the slurry, and (b) ) Squeezing the filter cake produced by the filtration step; and (c) heating and drying the squeezed filter cake. In the step (c), heating while sucking the filter chamber to a vacuum. There is provided a dehydration drying method characterized by heating a filter cake with a vacuum steam of 35 to 99 ° C. supplied as a medium.

  According to this structure, the 35-99 degreeC vacuum vapor | steam supplied in the filter chamber heats the filter cake obtained by filtering a slurry. As a result, the moisture contained in the filter cake can be removed and the filter cake can be dried. In addition, since vacuum vapor is directly used as a heating medium, the dehydrating and drying apparatus can be easily controlled.

  In the above step (c), the heating medium may exchange heat with the filter cake via a diaphragm provided in the filter chamber.

  In the step (c), the heating medium may exchange heat with the filter cake via a metal plate provided in the filter chamber.

  According to the present invention, it is possible to provide a dehydration drying apparatus and a dehydration drying method that do not require a high-temperature heating medium or complicated control.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic diagram for explaining the configuration of the dehydration drying apparatus 1000. In general, the dehydrating and drying apparatus 1000 includes a stock solution processing unit 1100 that processes a slurry that is a stock solution, a heating unit 1200 that supplies a heating medium to the stock solution processing unit 1100, and a slurry that is a stock solution that is stored in the stock solution processing unit 1100. And a vacuum suction unit 1400 that causes a pressure change in the stock solution processing unit 1100. Further, a cleaning liquid supply unit 1500 that supplies a cleaning liquid for cleaning the stock solution processing unit 1100 may be further included.

  The present invention mainly relates to the stock solution processing unit 1100 and the heating unit 1200 among those constituting the dehydration drying apparatus 1000 described above.

  First, the stock solution processing unit 1100 and the heating unit 1200 in the conventional dehydration drying apparatus 1000 will be described mainly with reference to the heating method, with reference to FIGS.

  FIG. 5 is a schematic diagram for explaining a heating method in the dehydration drying apparatus 1000 adopting a direct heat exchange method using steam. 6 and 7 are schematic diagrams for explaining the heating method in the dehydration drying apparatus 1000 adopting the indirect heat exchange method using steam, and FIG. 6 is an indirect diagram using a heat transfer tube and a heat exchange jacket in the hot water tank. FIG. 7 shows an indirect heat exchange method using a heat exchanger. 5 to 7 is a liquid level controller, TIC is a temperature indicating controller, and FIC is a flow rate indicating controller.

  A direct heat exchange type dehydrating and drying apparatus 1000 shown in FIG. 5 includes a filter press apparatus 10, a hot water tank 20, and a hot water circulation pump 30. Here, the filter press device 10 corresponds to the stock solution processing unit 1100, and the hot water tank 20 and the hot water circulation pump 30 correspond to the heating unit 1200.

  A filter chamber is formed in the filter press device 10, and slurry is supplied into the filter chamber to dehydrate and dry the slurry. The hot water tank 20 plays a role of producing hot water for heating the filter chamber in the filter press device 10 and storing water necessary for producing hot water. The hot water circulation pump 30 serves to circulate the hot water produced in the hot water tank 20 in the dehydrating and drying apparatus.

  In addition to the above equipment, the heating unit 1200 related to the direct heating method includes a steam pressure reducing valve 41 for reducing the pressure of steam supplied from the outside to the dehydrating and drying apparatus, a steam pressure adjusting valve 42 for adjusting the steam pressure, A hot water flow rate adjusting valve 43 that adjusts the flow rate of hot water circulated in the apparatus by the hot water circulation pump 30, and a number of cylinder type valves 44 and manual valves 45 are provided.

  In the direct heat exchange method, a predetermined amount of water set in accordance with the situation where a dehydration drying apparatus is installed is stored in the hot water tank 20, and steam supplied from the outside is directly supplied to the hot water tank 20. Then, warm water is produced by directly heating the water. The hot water tank 20 is agitated by a stirrer 21 with a motor for agitating water, and is heated efficiently. The direct heat exchange system is a system in which warm water produced as described above is supplied to the filter press apparatus 10 and the filter cake obtained by filtering the slurry is heated and dried.

  In this method, heat of steam is used to make water warm, and condensed water generated at that time is added to the hot water tank 20. In addition, since it is necessary to keep the heated hot water until drying is started, the amount of water in the hot water tank 20 is increased by the amount of condensation of steam. When hot water is circulated at the start of drying, the water level in the hot water tank 20 decreases, and if the water is supplied into the tank 20, the temperature of the hot water decreases. I have to do it. In addition, since the condensed water generated during drying and the warm water held in the dehydrating / drying apparatus are added to the warm water tank 20 at the end of drying, the capacity of the warm water tank 20 becomes a problem. As described above, the dehydration drying apparatus using the direct heat exchange method has a problem that it is difficult to set the capacity of the hot water tank 20 and it is difficult to control the liquid level.

  The indirect heat exchange type dehydrating and drying apparatus shown in FIG. 6 includes a filter press apparatus 10, a hot water tank 20, and a hot water circulation pump 30. Here, the filter press device 10 corresponds to the stock solution processing unit 1100, and the hot water tank 20 and the hot water circulation pump 30 correspond to the heating unit 1200.

  The various valves and measuring devices provided in the filter press device 10, the hot water circulation pump 30, and the heating unit 1200 have the same functions and the same effects as those of the direct heat exchange method described above. Detailed description will be omitted.

  The hot water tank 20 plays a role of producing hot water for heating the filter chamber in the filter press apparatus 10 and storing water necessary for producing hot water. In the indirect heat exchange method, a predetermined amount of water set in accordance with the situation where a dehydration drying apparatus is installed is stored in the hot water tank 20, and a pipe through which steam supplied from the outside flows is provided in the hot water pump 20. By being piped, water is heated indirectly to produce hot water. The steam deprived of heat in the hot water tank 20 passes through the steam trap 50 and is discharged out of the apparatus as a drain. The hot water tank 20 is agitated by a stirrer 21 with a motor for agitating water, and is heated efficiently.

  The indirect heat exchange type dehydration drying apparatus shown in FIG. 7 includes a filter press device 10, a hot water tank 20, a hot water circulation pump 30, and a heat exchanger 60. Here, the filter press apparatus 10 corresponds to the stock solution processing unit 1100, and the hot water tank 20, the hot water circulation pump 30, and the heat exchanger 60 correspond to the heating unit 1200.

  Since the various valves and measuring devices provided in the filter press device 10, the hot water circulation pump 30, and the heating unit 1200 have the same functions and the same effects as those of the indirect heat exchange method, Detailed description is omitted.

  In the indirect heat exchange method using the heat exchanger 60, a stirrer or the like is not installed in the hot water tank 20, and the water stored in the hot water tank 20 is introduced into the heat exchanger 60. In this heat exchanger 60, it is heated indirectly by the heat of the steam supplied from the outside of the dehydrating and drying device, and becomes hot water.

  Unlike the direct heat exchange method, the two indirect heat exchange methods described above do not include the amount of steam condensation as the capacity of the hot water tank 20. However, the liquid level of the hot water tank 20 varies in the same way during drying and at the end of drying. However, unlike the direct heat exchange method, the liquid level fluctuation of the hot water tank 20 is not so large, and the liquid level control of the hot water tank 20 is relatively easy. However, there is a problem that the condensed water of steam generated as a result of indirectly heating the water in the hot water tank 20 must be considered for use other than disposal.

(First embodiment)
In order to solve the above-described problems, the present inventor has come up with the following dehydration drying apparatus 1000. The dehydration drying apparatus 1000 according to the first embodiment of the present invention shown in FIG. 2 includes a filter press apparatus 100, a separator 200, an ejector 300, a circulation tank 400, and a circulation pump 500. Here, the filter press apparatus 100 corresponds to the stock solution processing unit 1100, and the separator 200, ejector 300, circulation tank 400, and circulation pump 500 correspond to the heating unit 1200.

  In addition to the above equipment, the heating unit 1200 according to the present embodiment includes a steam pressure reducing valve 710 for reducing the pressure of steam supplied from the outside to the dehydration drying apparatus 1000, and a steam pressure adjusting valve for adjusting the steam pressure. 720 and a number of manual valves 730.

  A filter chamber is formed in the filter press apparatus 100, slurry is supplied into the filter chamber, and dehydration and drying are performed. The filter press apparatus 100 according to the present embodiment will be described in detail again below.

  The separator 200 is used to remove drain from the vapor supplied to the separator 200. In the present embodiment, the separator 200 is connected to the ejector 300, and the drain is sucked by the ejector 300 and the inside of the separator 200 is depressurized to an atmospheric pressure or lower.

  The ejector 300 uses the water supplied from the circulation tank 400, which is a water storage tank, by the circulation pump 500 as a drive source, and efficiently sucks drain from the separator 200 and also sucks condensed water generated by the filter press device 100. Fulfill. Further, the ejector effect also serves to reduce the pressure in the system from the separator 200 to the filter press apparatus 100 to below atmospheric pressure.

  The system from the separator 200 to the filter press apparatus 100 is monitored by a temperature indicating controller (TIC) and a pressure indicating controller (PIC), and the steam pressure adjusting valve 720 is controlled based on the result. Is done.

  Further, the drain or condensed water sucked by the ejector 300 is stored in the circulation tank 400 via, for example, the steam trap 600 and reused as a drive source of the ejector 300.

  The vacuum steam used in the vacuum steam heating type dehydration drying apparatus 1000 according to the present embodiment can be obtained as follows.

  The superheated steam at atmospheric pressure or higher supplied from the outside of the dehydration drying apparatus according to the present embodiment is reduced in temperature while removing the superheat degree by the water supplied from the outside of the dehydration drying apparatus according to the present embodiment, It becomes wet saturated steam. The wet saturated vapor passes through the separator 200 and drainage is removed to form vacuum vapor. In addition, an ejector 300 is connected to the separator 200, and the ejector 300 sucks the drain. In accordance with suction by the ejector 300, the separator 200 is depressurized to an atmospheric pressure or lower. As a result, the vacuum vapor generated by the separator 200 also becomes atmospheric pressure or lower, and the temperature is reduced to a predetermined temperature.

  The vacuum steam as the heating medium can shorten the drying time as the temperature of the vacuum steam is higher, so that it can be set to 35 to 99 ° C, for example, and preferably 90 to 99 ° C. However, if there is a limit on the allowable temperature of the object to be heated, it shall be below that temperature. For example, when processing a food additive such as a food additive that cannot be heated to 40 ° C. or higher, the temperature of the vacuum vapor used is set to 40 ° C. or lower. Even when the allowable temperature of such an object to be heated is limited, the drying time can be shortened compared to using hot water having the same temperature as the vacuum steam.

  When the temperature of the vacuum steam exceeds 99 ° C., the internal pressure of the pressure vessel such as the piping exceeds the atmospheric pressure due to the vacuum steam, which may cause a safety problem. In addition, the dehydration drying apparatus 1000 according to the present embodiment can generate vacuum vapor having a temperature of 30 ° C. or higher by a vacuum generator (not shown), but uses vacuum vapor of 35 ° C. or higher. Thus, the dehydrating and drying apparatus 1000 can be stably operated.

  The vacuum vapor heating type dehydration drying apparatus 1000 according to the present embodiment uses the vacuum vapor thus obtained as a heating medium.

  Note that a predetermined amount of water is stored in the circulation tank 400 provided in the dehydration drying apparatus 1000 according to the present embodiment, and is used as a drive source for driving the ejector 300. Further, unlike the conventional dehydrating and drying apparatus, the water stored in the circulation tank 400 is characterized in that it is not used to be heated to generate hot water or steam. In addition, since the water stored in the circulation tank 400 may be used as a drive source for the ejector 300, the capacity of the circulation tank 400 only needs to secure a water amount that does not cause cavitation in the circulation pump 500. Further, unlike the conventional method, the dehydration drying apparatus 1000 according to the present embodiment does not require complicated liquid level control of the tank.

  Subsequently, the filter chamber 135 in the dehydration drying apparatus 1000 using the vacuum vapor heating method according to the first embodiment of the present invention will be described in detail with reference to FIG. The filter chamber 135 provided in the filter press apparatus 100 is a part forming the core of the stock solution processing unit 1100. Here, FIG. 3 is a schematic diagram for explaining a vacuum vapor heating method in the filter press apparatus 100 according to the present embodiment.

  The filter chamber 135 according to this embodiment provided in the filter press device 100 includes a filter plate 110 facing each other, and a pair of diaphragms (pressed membranes) provided between the filter plate 110 and substantially parallel to the filter plate 110. ) 120 and a pair of filter cloths 130 provided substantially parallel to the diaphragm 120 between the pair of diaphragms 120. That is, the filter plate 110, the diaphragm 120, and the filter cloth 130 are layered and overlapped. And the slurry which is a stock solution is supplied from the exterior of the filter press apparatus 100 to the filter chamber 135 which is an internal space formed between a pair of filter cloths 130 facing each other, and the following processing steps are performed on the supplied slurry. Is done.

  The filter plate 110 can be formed using, for example, a resin having excellent heat resistance. As an example of the resin excellent in heat resistance, for example, a polypropylene resin can be mentioned.

  The diaphragm 120 provided between the filter plates 110 facing each other and supported by the filter plate 110 may use, for example, an ethylene / propylene copolymer (EPM) or an ethylene / propylene / diene copolymer (EPDM). Is possible. The diaphragm 120 may be formed integrally with the filter plate 110, and the filter plate 110 itself may have the function of the diaphragm 120.

  The filter cloth 130 provided between the diaphragms 120 and supported by the diaphragm 120 serves to filter the slurry supplied to the filter chamber 135 formed between the filter cloths 130 into moisture and solid components. The filter cloth 130 can be formed using a known material.

  Note that a plurality of filter chambers 135 formed as described above may be provided in the filter press apparatus 100. By providing a plurality of filter chambers 135 in the filter press apparatus 100, a large amount of slurry can be processed.

  Subsequently, the dehydration drying method of the dehydration drying apparatus 1000 using the vacuum vapor heating method according to the present embodiment will be described in detail with reference to FIGS. The dehydration drying method of the dehydration drying apparatus according to the present embodiment includes a filtration process, a pressing process, a drying process, a frame opening process, and the like.

  First, a stock solution (slurry) is supplied to a filter chamber 135 formed between a pair of filter cloths 130 from a stock solution supply port (not shown) provided in the filter press apparatus 100 according to the present embodiment, and the filter cloth 130 is supplied. Is filtered into a filtrate and a solid component (filter cake) (filtering step). In this step, the filtrate discharged from the filter chamber 135 formed between the filter cloths 130 is discharged from the filter press device 100 through a filtrate discharge port (not shown) to the outside of the filter chamber 135.

  Then, as shown in FIG.3 (b), compressed water is pumped in the diaphragm 120, and the diaphragm 120 is crimped | bonded to the filter cloth 130 (squeezing process). By doing so, the volume of the filter chamber 135 is reduced, and the water still remaining in the filter cake can be discharged out of the filter chamber 135 as a filtrate.

  Next, as shown in FIG. 3 (c), while vacuum suctioning the filter chamber 135 by the vacuum suction part 1400, the vacuum vapor of, for example, about 90 ° C. obtained as described above into the diaphragm 120 is used as the heating medium. Supply as. The supplied vacuum vapor exchanges heat with the filter cake via the diaphragm 120. At this time, the filter cake in the filter chamber 135 is under a pressure lower than the atmospheric pressure due to vacuum suction, and the boiling point of water becomes lower than the atmospheric pressure. Therefore, the water remaining in the filter cake evaporates by exchanging heat with vacuum steam, and as a result, the filter cake can be dried (drying process).

  In addition, in the dehydration drying apparatus 1000 according to the present embodiment, the heat transfer amount of the heating medium is increased by changing the heating medium from sensible heat heating with conventional hot water to vacuum steam and switching to heating with latent heat of condensation. be able to. By increasing the amount of heat transfer, the evaporation rate of water remaining in the filter cake is improved, and the time for drying the filter cake (drying time) can be shortened.

  Condensed water generated as a result of the heat exchange of the vacuum steam with the filter cake is sucked by the ejector 300 through the steam trap 600 provided in the heating unit 1200 and stored in the circulation tank 400. The stored condensed water is reused as a drive source for driving the ejector 300.

  Subsequently, as shown in FIG. 3D, the filter press device 100 is unframed and the dried filter cake is discharged (frame opening step).

  As described above, the slurry supplied to the filter chamber 135 is filtered, squeezed, and dried to produce a filter cake from which moisture has been removed, whereby the slurry can be processed.

(Second Embodiment)
Subsequently, the filter chamber 135 in the dehydration drying apparatus 1000 using the vacuum vapor heating method according to the second embodiment of the present invention will be described in detail with reference to FIG. Here, FIG. 4 is a schematic diagram for explaining a vacuum steam heating method in the filter press apparatus 100 according to the present embodiment.

  The filter chamber 135 according to the present embodiment provided in the filter press apparatus 100 includes a filter plate 110, a metal plate 140 facing the filter plate 110, and the filter plate 110 between the filter plate 110 and the metal plate 140. A diaphragm 120 provided substantially parallel to the diaphragm 120 and a pair of filter cloths 130 provided substantially parallel to the diaphragm 120 and the metal plate 140 are provided between the diaphragm 120 and the metal plate 140. That is, the filter plate 110, the diaphragm 120, the filter cloth 130, and the metal plate 140 overlap each other in layers. Then, a slurry as a stock solution is supplied from the outside of the filter press apparatus 100 to a filter chamber 135 which is an internal space formed between a pair of filter cloths 130 facing each other, and the following processing is performed on the supplied slurry. A process is performed.

  Since the filter plate 110, the diaphragm 120, and the filter cloth 130 have the same functions as those of the first embodiment and have the same effects, detailed description thereof is omitted.

  As shown in FIG. 4, the metal plate 140 includes a pair of opposed metal plates, and a plurality of shaft members are provided between the metal plates so as to form a plurality of hollow portions communicating with each other. ing. As said metal plate, it is preferable to use what is excellent in heat conductivity and corrosion resistance, for example. As an example of such a metal, a stainless steel plate such as SUS304 can be used. Moreover, as a shaft member for forming a hollow part, the same material as a metal plate may be used, for example, or a resin having heat resistance may be used. Further, these metal plates and the shaft member may be integrally formed. The hollow portion formed in this way functions as a flow path for the vacuum vapor that is the heating medium.

  A plurality of filter chambers 135 formed as described above are provided in the filter press apparatus 100. By providing a plurality of filter chambers 135 in the filter press apparatus 100, a large amount of slurry can be processed. When a plurality of filter chambers 135 are provided, the filter plates 110 and the metal plates 140 are alternately arranged so that the metal plates 140 in the adjacent filter chambers 135 face each other.

  Subsequently, the dehydration drying method of the dehydration drying apparatus 1000 using the vacuum vapor heating method according to the present embodiment will be described in detail with reference to FIGS. The dehydration drying method of the dehydration drying apparatus according to the present embodiment includes a filtration process, a pressing process, a drying process, a frame opening process, and the like.

  Since the filtration process and the pressing process shown in FIGS. 4A and 4B are the same as those in the first embodiment, detailed description thereof is omitted.

  In the step shown in FIG. 4C, the filter chamber 135 is vacuum-sucked by the vacuum suction portion 1400, and the hollow portion formed in the metal plate 140 is used as a flow path, for example, about 90 A vacuum vapor of ℃ is circulated as a heating medium. In the present embodiment, the supplied vacuum vapor exchanges heat with the filter cake via the metal plate 140. At this time, the filter cake in the filter chamber 135 is under a pressure lower than the atmospheric pressure due to vacuum suction, and the boiling point of water becomes lower than the atmospheric pressure. Therefore, the water remaining in the filter cake evaporates by exchanging heat with vacuum steam, and as a result, the filter cake can be dried (drying process).

  In the present embodiment, since the metal plate 140 is formed using a metal having excellent thermal conductivity, the amount of heat transfer is further increased as compared with the first embodiment of the present invention using a resin.

  In FIG. 4C, the vacuum vapor is circulated through the hollow portion formed in the metal plate 140, but the vacuum vapor may also be circulated in the diaphragm 120 together with this. By allowing the vacuum steam to flow through the diaphragm 120 and the metal plate 140, it is possible to evaporate water remaining on the filter cake from both sides of the filter cake.

  Subsequently, as shown in FIG. 4 (d), the filter press device 100 is opened to discharge the dried filter cake (frame opening step).

  As described above, the slurry supplied to the filter chamber 135 is filtered, squeezed, and dried to produce a filter cake from which moisture has been removed, whereby the slurry can be processed.

  Hereinafter, the dehydration drying apparatus and the dehydration drying method thereof according to the first and second embodiments of the present invention will be described in detail with reference to examples.

Example 1
In this example, the drying time was measured for the dehydration drying apparatus having the filter chamber shown in FIG. 3 using calcium carbonate as the slurry.

The drying time was 100 kg of calcium carbonate (dried solid) containing 40% moisture, and the time required for the moisture to reach 40% to 5% was used. Here, the absolute pressure in the filter chamber (space 135 in FIG. 3) was 10 kPa · A, and vacuum steam at 90 ° C. was used as the heating medium. In the filter chamber, the temperature on the evaporation side was 45.8 ° C. The area where the vacuum vapor is in contact with calcium carbonate, that is, the heat transfer area, was 10 m ² .

(Example 2)
The drying time was measured in the same manner as in Example 1 except that the operating pressure was 8 kPa · A, the temperature of the vacuum vapor used was 60 ° C., and the evaporation side temperature was 41.5 ° C.

(Example 3)
The drying time was measured in the same manner as in Example 1 except that the operating pressure was 3 kPa · A, the temperature of the vacuum vapor used was 35 ° C., and the evaporation side temperature was 24 ° C.

(Comparative Example 1)
The drying time was measured in the same manner as in Example 1 except that 90 ° C. warm water was used as the heating medium.

(Comparative Example 2)
The drying time was measured in the same manner as in Example 2 except that hot water of 60 ° C. was used as the heating medium.

(Comparative Example 3)
The drying time was measured in the same manner as in Example 3 except that hot water of 35 ° C. was used as the heating medium.

  The obtained results are shown in Table 1 below.

Table 1

  In Table 1 above, kg DS as a unit of the calcium carbonate treatment amount means the number of kg of calcium carbonate in a dry solid state. In addition,% of unit of water. B. Indicates the moisture content when the whole is 100. For example, 40% W.W. B. Means 40% moisture and 60% dry solids.

  As apparent from Table 1 above, by using the heating method using vacuum steam according to the present embodiment, the drying time can be shortened compared to the drying time in the conventional heating method using hot water. Was found to be possible.

Example 4
The drying time was measured in the same manner as in Example 1 except that the dehydration drying apparatus having the filter chamber shown in FIG. 4 was used.

(Example 5)
The drying time was measured in the same manner as in Example 2 except that the dehydration drying apparatus having the filter chamber shown in FIG. 4 was used.

(Example 6)
The drying time was measured in the same manner as in Example 3 except that the dehydration drying apparatus having the filter chamber shown in FIG. 4 was used.

(Comparative Example 4)
The drying time was measured in the same manner as in Example 4 except that warm water of 90 ° C. was used as the heating medium.

(Comparative Example 5)
The drying time was measured in the same manner as in Example 5 except that hot water of 60 ° C. was used as the heating medium.

(Comparative Example 6)
The drying time was measured in the same manner as in Example 6 except that 35 ° C. warm water was used as the heating medium.

  The results obtained are shown in Table 2 below.

Table 2

  As is clear from Table 2 above, the drying time is greatly reduced by using the heating method using vacuum steam according to the present embodiment, compared to the drying time in the conventional heating method using hot water. It turns out that it is possible.

  As described above, changing the heating medium from conventional sensible heat with hot water to vacuum steam at the same temperature results in heating by condensation latent heat, increasing the heat transfer, resulting in improved evaporation rate, and reduced drying time. We were able to shorten it.

  It was also found that the drying time can be shortened even when vacuum steam at the same temperature as hot water is used. From this result, it can be seen that the heating method using vacuum vapor according to the present embodiment can be applied to a filter press apparatus using a resin filter plate without changing the material of the contact portion of the heating medium.

  Furthermore, in the dehydrating and drying apparatus 1000 using the vacuum steam heating method according to the present embodiment, since vacuum steam is directly used as a heating medium, it is not necessary to perform heat exchange for obtaining warm water as in the related art. No time is required to raise the temperature to the operating temperature. As a result, it is possible to reduce the time required for dehydration drying. Furthermore, since the time required for dehydration drying can be shortened, the steam consumption can also be reduced. In addition, since hot water is unnecessary, it is not necessary to perform complicated device control due to changes in the amount of water and temperature, and the control of the device is simplified.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this example. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, in the above-described embodiment, a cleaning process for cleaning the filter cake may be provided between the filtering process and the pressing process. Moreover, you may provide the washing process which wash | cleans a filter cloth after a frame opening process. In such a cleaning process, it is possible to clean the filter cake itself or the filter cloth after the filter cake is removed with the cleaning liquid supplied from the cleaning liquid supply unit 1500.

  In the above-described embodiment, an example in which a polypropylene resin is employed as the filter plate has been described. However, the present invention is not limited to this example. For example, other resins can be used as long as they are strong enough to withstand the pressure of the filter press and heat resistant enough to withstand the temperature of the supplied vacuum vapor.

  In the above-described embodiment, an example in which a stainless steel plate is used as the metal plate has been described. However, the present invention is not limited to this example. Various metal plates can be used in consideration of the type and properties of the slurry supplied to the filter chamber.

It is a schematic diagram for demonstrating a dehydration drying apparatus. It is a schematic diagram of the dehydration drying apparatus using the vacuum vapor heating system which concerns on the 1st Embodiment of this invention. It is a schematic diagram for demonstrating the filter chamber in the dehydration drying apparatus using the vacuum vapor heating system which concerns on the 1st Embodiment of this invention. It is a schematic diagram for demonstrating the filter chamber in the dehydration drying apparatus using the vacuum vapor heating system which concerns on the 2nd Embodiment of this invention. It is a schematic diagram for demonstrating the dehydration drying apparatus using the direct heat exchange system by a vapor | steam. It is a schematic diagram for demonstrating the dehydration drying apparatus using the indirect heat exchange system by steam (a hot water tank provided with a heat exchanger tube and a heat exchange jacket). It is a schematic diagram for demonstrating the dehydration drying apparatus using the indirect heat exchange system (heat exchanger) by steam.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Filter press apparatus 110 Filter plate 120 Diaphragm 130 Filter cloth 135 Filter chamber 140 Metal plate 200 Separator 300 Ejector 400 Circulation tank 500 Circulation pump 600 Steam trap 710 Steam pressure reducing valve 720 Steam pressure regulating valve 730 Manual valve 1000 Dehydration drying apparatus 1100 Part 1200 Heating part 1300 Stock solution supply part 1400 Vacuum suction part 1500 Cleaning liquid supply part

Claims (8)

A dehydrating and drying apparatus for filtering and drying a slurry supplied to a filter chamber:
The filter chamber is provided between a filter plate made of resin facing each other, a pair of diaphragms substantially parallel to the filter plate, and provided between the diaphragms, and the diaphragm. A pair of filter cloths substantially parallel to
The filter chamber is used as a medium for indirectly heating the filter cake through the diaphragm while being sucked in vacuum through the filter cloth when the filter cake obtained by filtering the slurry is dried. A dehydrating and drying device characterized by being supplied with vacuum steam at ℃. A dehydrating and drying apparatus for filtering and drying a slurry supplied to a filter chamber:
The filter chamber includes a resin filter plate, a metal plate facing the filter plate, a diaphragm interposed between the filter plate and the metal plate, and substantially parallel to the filter plate, A pair of filter cloths provided between the diaphragm and the metal plate and substantially parallel to the diaphragm and the metal plate;
The filter chamber is a medium that indirectly heats the filter cake through the diaphragm or the metal plate while being sucked in vacuum through the filter cloth when the filter cake obtained by filtering the slurry is dried. As a dehydrating and drying apparatus, a vacuum steam of 35 to 99 ° C. is supplied. The dehydrating and drying device further includes a filter press device that removes moisture from the slurry,
The dehydrating and drying apparatus according to claim 1 or 2, wherein the filter chamber is provided in the filter press apparatus.   The dehydrating / drying apparatus according to claim 1, further comprising a separator that separates drain from steam supplied from outside the dehydrating / drying apparatus. The dehydrating and drying apparatus further includes an ejector and a water storage tank,
The ejector sucks condensed water generated when the vacuum steam passes through the filter chamber and the drain by using water stored in the water storage tank as a driving source. 4. The dehydration drying apparatus according to 4.   The dehydrating and drying apparatus according to claim 1, wherein the filter plate is a polypropylene resin.   The dehydrating and drying apparatus according to claim 2, wherein the metal plate is a stainless steel plate. A dehydration drying method for filtering and drying a slurry supplied to a filter chamber, comprising:
(A) filtering the slurry;
(B) squeezing the filter cake produced by the filtration step;
(C) heating and drying the squeezed filter cake;
Including
The filter plate provided in the filter chamber is a resin filter plate,
In the step (c), a diaphragm provided in the filter chamber by vacuum steam of 35 to 99 ° C. supplied as a heating medium while sucking the filter chamber to a vacuum through a filter cloth provided in the filter chamber. Alternatively, the dehydrating and drying method, wherein the filter cake is indirectly heated through a metal plate .

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