JP4715717B2 - Porous body manufacturing apparatus and porous body manufacturing method - Google Patents

Description

  The present invention relates to a porous body manufacturing apparatus and a porous body manufacturing method for manufacturing a sheet-like porous body having a three-dimensional network structure.

Conventionally, when manufacturing a sheet-like porous body, for example, as in Patent Document 1, a foamable slurry containing an inorganic powder, a foaming agent, an organic binder, a liquid solvent, and the like is molded into a sheet shape, and then molded. The foamable slurry sheet is foamed with a foaming agent, and the foamed slurry sheet is further dried and fired.
Foaming of the foamable slurry sheet is performed by heating the foamable slurry sheet with a molded body heater provided in the furnace. However, when the foamable slurry sheet is dried by heating, foaming becomes insufficient. Conventionally, in order to prevent the foamable slurry sheet from drying, a water tank having a water temperature adjusting heater is provided by storing water in the furnace, and the inside of the furnace is humidified by steam generated from the water tank.

  Moreover, although drying of a foamable slurry sheet may be performed using the air blower which blows toward a foamable slurry sheet like patent document 2, for example, in order to dry the whole foamable slurry sheet uniformly It is said that it is preferable to use a far-infrared device that uniformly heats the outer surface and the inside of the foamable slurry sheet.

Some sheet-like porous bodies manufactured as described above are configured such that the porosity gradually changes along the sheet surface direction as disclosed in Patent Document 3, for example. Such a porous body can be obtained by forming a foamable slurry sheet having a gradually changing thickness, then foaming, and compressing or rolling to a predetermined thickness before and after firing the dried foamable slurry sheet. .
In this way, the porous body whose porosity changes along the surface direction is, for example, a filter that efficiently captures foreign substances contained in the fluid by passing the fluid along the surface direction of the sheet, or the surface of the sheet It can be used for a medium that sucks water by capillary action along the direction and vaporizes it into gas, a gas diffusion layer of a fuel cell, and the like.
Japanese Patent No. 3282497 JP-A-10-267533 JP 2004-315909 A

  By the way, the sheet-like porous body is often used so as to pass or suck a fluid in the thickness direction, but conventionally, when the porosity is changed in the thickness direction, the pore diameter of the bubbles is small. A product in which different porous bodies are bonded to each other is manufactured, and there is no porous body configured such that such a structure or structure gradually changes in the thickness direction. Moreover, it is difficult to manufacture the porous body having the above configuration by the above-described conventional manufacturing method.

  This invention is made | formed in view of the above subject, Comprising: It aims at providing the sheet-like porous body from which a hole diameter changes gradually in the thickness direction.

  In order to achieve the above object, the present invention provides the following means.

  The porous body production apparatus of the present invention produces a porous body having a three-dimensional network structure by foaming and drying a foamable slurry sheet containing at least an inorganic powder, a foaming agent and a binder while being conveyed by a carrier sheet. A foaming means for foaming the foamable slurry sheet conveyed by the carrier sheet so as not to dry under high humidity conditions, and the foamable slurry sheet foamed in the foaming means Drying means for heating and drying, the drying means comprising a plurality of heating units for heating the foamable slurry sheet disposed on the carrier sheet, wherein the plurality of heating units are at least the carrier sheet. The upper surface and the lower surface of the foamable slurry sheet disposed above are divided and arranged so as to be individually heated, Serial heating unit wherein as upper and lower surfaces of the heating temperature of the foamable slurry sheet are different from each other by, and wherein the operation of each of the heating unit can be independently controlled.

  Further, the method for producing a porous body of the present invention is a porous material having a three-dimensional network structure by foaming and drying a foamable slurry sheet containing at least an inorganic powder, a foaming agent and a binder while being conveyed by a carrier sheet. A porous body manufacturing method for manufacturing a body, comprising: a foaming step of foaming the foamable slurry sheet so as not to dry under high humidity conditions; and a drying step of drying the foamed foamable slurry sheet. And, in the drying step, the heating temperature is different between the upper surface and the lower surface of the foamable slurry sheet disposed on the carrier sheet.

  The foamable slurry sheet is foamed in a foaming means (foaming step), whereby a large number of bubbles are formed inside or on the surface. And if a foaming slurry sheet is dried in a drying means (drying process), the water | moisture content in a foaming slurry sheet will volatilize, a viscosity will rise, and the growth of the said bubble will stop. That is, the higher the temperature at which the foaming slurry sheet is heated in the drying means, the faster the foaming slurry sheet is dried, and bubbles with small pore diameters are formed.

And according to the present invention, by individually controlling the operation of the heating unit for heating the upper surface and the heating unit for heating the lower surface, the heating temperature of the upper surface and the lower surface of the foamable slurry sheet can be made different. The temperature distribution of the foamable slurry sheet gradually changes from the upper surface toward the lower surface. Therefore, a large number of bubbles can be distributed in the dried sheet-like porous body so that the pore diameter of the bubbles gradually increases or decreases from the upper surface toward the lower surface.
Further, the three-dimensional network skeleton constituting the porous body is continuously connected. Therefore, the strength can be improved compared to the past in which a plurality of porous bodies having different pore diameters are simply pasted together as in the past. ) Can also prevent the filtrate from being concentrated.

Further, in the porous body manufacturing apparatus of the present invention, a plurality of the heating units arranged on at least one of the upper surface side and the lower surface side of the foamable slurry sheet are arranged over the width direction of the foamable slurry sheet, The operation of each of the heating units can be independently controlled such that the heating temperature distribution of the upper surface or the lower surface heated by the plurality of heating units gradually changes in the width direction.
In this case, it is possible to easily manufacture a sheet-like porous body in which the bubble diameter gradually changes over the width direction.

Moreover, the porous body manufacturing apparatus of the present invention is characterized in that the heating unit includes a blower unit that blows heated gas toward the upper surface or the lower surface side of the foamable slurry sheet.
In this case, the upper surface and the lower surface of the foamable slurry sheet can be easily heated without unevenness. For this reason, for example, the entire surface of the foamable slurry sheet can be heated to a uniform temperature, and the pore size of a large number of bubbles distributed in the surface direction can be easily obtained in the sheet-like porous body. It becomes possible to arrange them uniformly.

Further, for example, it is possible to prevent the heating temperature distribution in the width direction from becoming discontinuous, and to smoothly change the size of many bubbles distributed in the width direction in the sheet-like porous body.
Furthermore, since the heated gas is directly blown onto the upper surface of the foamable slurry sheet, it can be dried particularly efficiently.

  In the porous body manufacturing apparatus of the present invention, the foaming means has a transport inlet and a transport outlet through which the carrier sheet and the foamable slurry sheet can pass, and a predetermined amount below the transport inlet and the transport outlet. A humidifying heating container capable of storing water, a sheet heater provided in the humidifying heating container for heating the foamable slurry sheet, a larger amount of the water than the humidifying heating container is stored, and the temperature of the water A storage tank having a water temperature adjusting heater for adjusting the temperature, and a circulation mechanism for circulating the water between the humidification heating container and the storage tank.

  In this case, since the water heated in the storage tank in advance is supplied to the humidification heating container by the circulation mechanism, and the water in the humidification heating container is discharged to the storage tank, the temperature of the water in the humidification heating container is uniform. Can be held in. As a result, it is possible to easily maintain the temperature distribution in the humidified heating container uniformly, and it is possible to easily improve the accuracy of temperature setting in the humidified heating container.

Here, the size of the bubbles formed in the foaming means varies depending on the temperature in the humidification heating container, but as described above, the temperature distribution in the humidification heating container becomes uniform, so that the size of the bubbles is increased. Can be made uniform throughout the foamable slurry sheet.
And by making the size of the bubbles formed in the foaming means uniform in this way, it becomes possible to set the size of the bubbles in the drying means with high accuracy. Therefore, it is possible to provide a sheet-like porous body in which the distribution of bubbles whose size gradually changes in the thickness direction and the width direction is set with high accuracy.

  ADVANTAGE OF THE INVENTION According to this invention, the sheet-like porous body from which a hole diameter changes gradually across the thickness direction or the width direction can be manufactured easily.

Hereinafter, the porous body manufacturing apparatus according to the embodiment of the present invention will be described with reference to FIGS. 1 to 4.
As shown in FIG. 1, a porous body manufacturing apparatus 1 according to this embodiment is a foamable slurry containing a metal powder (inorganic powder), a foaming agent, an organic binder (binder), a liquid solvent (binder), and the like. S1 is formed into a sheet shape, a sheet-like foamable slurry (hereinafter referred to as foamable slurry sheet S2) is foamed and dried, and a porous green sheet (porous body) G having a three-dimensional network structure is obtained. To manufacture.

  Here, examples of the metal powder contained in the foamable slurry S1 include nickel, copper, iron, SUS, chromium, cobalt, gold, silver, etc., but all metals that can be powdered and sintered are used. be able to. Examples of the foaming agent include water-insoluble hydrocarbon-based organic solvents having 5 to 8 carbon atoms (for example, neopentane, hexane, heptane) and the like. At least gas is generated and bubbles in the foamable slurry S1 are removed. Any compound can be used as long as it can be grown, and various compounds that decompose at a predetermined temperature to generate gas and volatile organic solvents can be used.

  Furthermore, examples of the organic binder include water-soluble organic binders such as methylcellulose and hydroxypropylmethylcellulose, and at least have the function of maintaining the shape of the porous green sheet when the foamable slurry sheet S2 is dried. If it is, it can be used. Examples of the liquid solvent include water, and any liquid solvent can be used as long as it can be volatilized into the atmosphere by heating at a high temperature and has a lower volatility and a higher boiling point than the foaming agent. As the foaming slurry S1, for example, the one disclosed in Japanese Patent No. 3282497 is more preferable.

  The porous body manufacturing apparatus 1 includes a long carrier sheet 3 conveyed by a plurality of rollers, and a forming apparatus (forming means) that supplies the foamable slurry S1 onto the carrier sheet 3 and forms the foamable slurry sheet S2. ) 5, a foaming device (foaming means) 7 for foaming the foamable slurry sheet S2 conveyed by the carrier sheet 3 so as not to be dried under high humidity conditions, and heating and drying the foamed slurry sheet S2. And a drying device (drying means) 9.

The carrier sheet 3 is made of, for example, a PET film or the like, and is conveyed in the longitudinal direction (A direction) by a plurality of rollers 10.
The forming device 5 extends between the carrier sheet 3 and the hopper 11 that stores the foamable slurry S1 and supplies it onto the carrier sheet 3 and the foamable slurry S1 that is supplied onto the carrier sheet 3 that moves in the A direction. And a doctor blade 13 for forming the foamable slurry sheet S2.

As shown in FIG. 2, the foaming apparatus 7 has a transport inlet 15a and a transport outlet 15b through which the carrier sheet 3 and the foamable slurry sheet S2 can pass, and a predetermined amount of water W below the transport inlet 15a and the transport outlet 15b. A box-shaped humidification heating container 15 capable of storing water, a storage tank 17 that stores a larger amount of water than the humidification heating container 15, and a circulation mechanism 19 that circulates the water W between the humidification heating container 15 and the storage tank 17. And.
A water temperature adjusting heater 21 that adjusts the temperature of the water W is provided inside the storage tank 17, and the humidified heating is performed by supplying the water W heated thereby into the humidifying heating container 15 by the circulation mechanism 19. The atmosphere in the container 15 can be maintained at a predetermined humidity. In addition, the storage tank 17 is provided with a water supply port 22 for replenishing the water W. When the water W in the storage tank 17 decreases, the water W is automatically replenished. Yes.

  The circulation mechanism 19 includes a supply unit 23 that supplies water W from the storage tank 17 into the humidification heating container 15, and a discharge unit 25 that discharges the water W in the humidification heating container 15 to the storage tank 17. . The supply unit 23 is arranged in the middle of the supply pipe 27 and the supply pipe 27 that opens to the lower part of the storage tank 17 and the humidification heating container 15, and flows the water W of the storage tank 17 toward the humidification heating container 15. And a pump 29. Further, the discharge unit 25 is constituted by a discharge pipe 31 that opens to the lower part of the humidification heating container 15 and the upper part of the storage tank 17.

Here, the opening end 27a of the supply pipe 27 that opens into the humidification heating container 15 is disposed on one end side in the humidification heating container 15 located on the upstream side in the conveyance direction of the carrier sheet 3, for example, and the humidification heating container An opening end 31 a of the discharge pipe 31 that opens to 15 is arranged at the other end in the humidification heating container 15 that is located downstream in the conveyance direction of the carrier sheet 3. For this reason, the water W supplied to the one end part in the humidification heating container 15 flows from one end part of the humidification heating container 15 to the other end part, and is then discharged from the other end part in the humidification heating container 15. Become.
The open end 31 a of the discharge pipe 31 that opens to the humidification heating container 15 protrudes from the bottom surface 15 c in the humidification heating container 15, so that a predetermined amount of water W is stored in the humidification heating container 15. It has become.

  In this way, the water W heated in the storage tank 17 is supplied into the humidification heating container 15 by the circulation mechanism 19, and the water W in the humidification heating container 15 is discharged to the storage tank 17. By constantly flowing the water W in the container 15 from one end to the other end of the circulation mechanism 19, the temperature of the water W in the humidified heating container 15 can be kept uniform. As a result, the temperature distribution in the humidification heating container 15 can be easily maintained uniformly, and the accuracy of temperature setting in the humidification heating container 15 can be easily improved.

  Further, a sheet heating heater 33 for heating the foamable slurry sheet S2 is provided immediately below the carrier sheet 3 in the humidified heating container 15 to promote foaming of the foamable slurry sheet S2. . A plurality of plate heaters 35 are provided on the upper wall surface of the carrier sheet 3 in the humidified heating container 15, and play a role in preventing condensation of water W on the wall surface. For example, a carbon plate heater is used as the sheet heater 33 and the plate heater 35.

As shown in FIG. 3, the drying device 9 is disposed on the carrier sheet 3 in a box-shaped heating furnace 37 having a transport inlet 37a and a transport outlet 37b through which the carrier sheet 3 and the foamable slurry sheet S2 can pass. A plurality of blowing units (heating units) 39 and 41 for heating the foamable slurry sheet S2 are provided.
The plurality of air blowing units 39 and 41 are arranged so as to separately heat the upper surface S2a and the lower surface S2b of the foamable slurry sheet S2, and each of the air blowing units 39 and 41 is an upper surface of the foamable slurry sheet S2. The heated gas is blown toward S2a or the lower surface S2b.

  That is, the blower units 39 and 41 are provided with blowers 43 and 45 for blowing gas from the outside into the heating furnace 37 and the gas blown into the heating furnace 37 on the upper side or the lower side of the foamable slurry sheet S2. The blowing pipes 47 and 49 that guide and blow toward the upper surface S2a or the lower surface S2b of the foamable slurry sheet S2 from the plurality of blowing outlets 47a and 49a, and the inside of the blowing pipes 47 and 49 in front of the blowing outlets 47a and 49a Heating heaters 51 and 53 for heating the passing gas are provided. Here, the plurality of outlets 47a and 49a are arranged at equal intervals along the conveying direction of the foamable slurry sheet S2, and the gas blown out from each of the outlets 47a and 49a is the foaming slurry sheet S2. It is designed to be sprayed evenly across the width direction.

In this configuration, the gas blown out from the outlet 47a of the blower pipe 47 disposed on the upper side of the foamable slurry sheet S2 is directly blown to the upper surface S2a of the foamable slurry sheet S2, and thereby the foamable slurry sheet. The upper surface S2a of S2 is heated. Moreover, since the gas blown out from the blowout port 49a of the blower pipe 49 disposed on the lower side of the foamable slurry sheet S2 is actually blown toward the carrier sheet 3, the bottom surface of the foamable slurry sheet S2 S2b is heated via the carrier sheet 3.
Moreover, in this structure, the operation | movement of each heater 51,53 can be controlled independently, and, thereby, the temperature of the gas sprayed toward the upper surface S2a and lower surface S2b side of the foamable slurry sheet S2 Can be made different from each other. That is, the heating temperatures of the upper surface S2a and the lower surface S2b of the foamable slurry sheet S2 by the plurality of air blowing units 39, 41 can be made different from each other.

Next, the manufacturing method of the porous green sheet G by the porous body manufacturing apparatus 1 configured as described above will be described.
In this manufacturing method, first, the foamable slurry S1 supplied from the hopper 11 onto the carrier sheet 3 is extended between the moving carrier sheet 3 and the doctor blade 13 to form a sheet-like foamable slurry sheet S2. (Molding process).

Next, the foamable slurry sheet S2 is conveyed into the humidification heating container 15 of the foaming device 7 by the carrier sheet 3, and the foamable slurry sheet S2 is foamed in the humidification heating container 15 (foaming step).
In this foaming step, the foaming agent contained in the foamable slurry sheet S2 is foamed by heating with the sheet heater 33 or the like, so that a large number of bubbles are formed inside or on the surface of the foamable slurry sheet S2. At this time, although the size of the pore diameter of the formed bubbles varies depending on the temperature in the humidification heating container 15, the temperature distribution in the humidification heating container 15 is uniformly maintained by providing the storage tank 17 and the circulation mechanism 19. Therefore, the size of the bubbles can be made uniform throughout the foamable slurry sheet S2.

Then, the foamed slurry sheet S2 is conveyed by the carrier sheet 3 from the humidified heating container 15 into the heating furnace 37 of the drying device 9, and the foamable slurry sheet S2 is dried in the heating furnace 37 ( Drying process), the production of the porous green sheet G is completed.
In this drying step, when the foamable slurry sheet S2 is dried, the liquid solvent (water) contained in the foamable slurry sheet S2 is volatilized to increase the viscosity, thereby stopping the growth of bubbles. That is, the higher the temperature at which the foamable slurry sheet S2 is heated in the heating furnace 37, the faster the foamable slurry sheet S2 is dried, and bubbles with smaller pore diameters are formed.

Further, in this drying step, a heater 51 for heating the gas blown to the upper surface S2a of the foamable slurry sheet S2 and a heater 53 for heating the gas blown to the lower surface S2b side of the foamable slurry sheet S2 are individually provided. The temperature of the gas sprayed toward the upper surface S2a and lower surface S2b side of the foamable slurry sheet S2 is controlled to be different from each other. That is, the heating temperature is varied between the upper surface S2a and the lower surface S2b of the foamable slurry sheet S2. Thereby, the temperature distribution of the foamable slurry sheet S2 gradually changes from the upper surface S2a toward the lower surface S2b.
Therefore, a large number of bubbles can be distributed in the dried porous green sheet G so that the size of the bubbles gradually increases or decreases from the upper surface toward the lower surface. That is, the porous green sheet G in which the pore diameter (porosity) of the bubbles gradually changes in the thickness direction is manufactured.

  As a specific example, when the temperature of the gas blown to the upper surface S2a of the foamable slurry sheet S2 is set lower than the temperature of the gas blown to the lower surface S2b, for example, as shown in FIG. Thus, the porous green sheet G in which the size of the bubbles B gradually decreases toward the lower surface G2 is manufactured. In the model diagram of the porous green sheet G shown in FIG. 4, a large number of bubbles B are independently formed only inside the porous green sheet G. And open to the upper surface G1 and the lower surface G2.

As described above, according to the porous body manufacturing apparatus 1 and the manufacturing method of the porous green sheet G according to the present embodiment, the porous green sheet G in which the pore diameter of the bubbles B gradually changes in the thickness direction is easily manufactured. can do.
Further, since the drying apparatus 9 heats the upper surface S2a and the lower surface S2b of the foamable slurry sheet S2 by blowing heated gas, the entire upper surface S2a and the entire lower surface S2b of the foamable slurry sheet S2 are easily uneven. It can be heated without any problems. For this reason, it can be heated to a uniform temperature over the entire upper surface S2a and the entire lower surface S2b of the foamable slurry sheet S2, and this facilitates the size of many bubbles distributed in the surface direction in the porous green sheet G. Can be evenly aligned.

Furthermore, in the drying apparatus 9, since the heated gas is directly sprayed on the upper surface S2a of the foamable slurry sheet S2, the drying can be performed particularly efficiently.
Further, in the foaming device 7, air bubbles having a uniform size can be formed over the entire foamable slurry sheet S 2, and therefore the size of the air bubbles can be set with high accuracy in the drying device 9. . Therefore, it is possible to provide a porous green sheet G in which the distribution of bubbles whose size gradually changes in the thickness direction is set with high accuracy.
Furthermore, the three-dimensional network skeleton constituting the porous green sheet G is continuously connected. Therefore, in the porous fired body obtained by degreasing and firing the porous green sheet G, the strength is improved as compared with a conventional case in which a plurality of porous bodies having different pore sizes are pasted together. In addition, there is also an effect that it is possible to prevent the filtrate from being concentrated on the discontinuous surface (bonding surface) during filtration of the filter.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
That is, the plurality of blower units 39 and 41 are constituted by, for example, the same blower and heater, and only the blower pipes 47 and 49 located on the downstream side of the heater are provided on the upper side and the lower side of the foamable slurry sheet S2. Each may be arranged.

That is, the blower unit 39 that blows gas onto the upper surface S2a of the foamable slurry sheet S2 is configured by the blower, the heater, and the blower pipe 47 disposed on the upper side of the foamable slurry sheet S2, and the blower described above. You may comprise the ventilation unit 41 which blows gas on the lower surface S2b side of the foamable slurry sheet S2 with the heater and the blower pipes 47 and 49 arranged on the lower side of the foamable slurry sheet S2.
In the case of this configuration, a changeover switch for switching the blowing of gas toward the outlets 47a and 49a is provided in the middle of each of the blower pipes 47 and 49 branched on the downstream side of the heater. By individually controlling the operation, the heating temperatures of the upper surface S2a and the lower surface S2b of the foamable slurry sheet S2 can be made different from each other.

  Moreover, in the said embodiment, although the several ventilation unit 39,41 was divided and arrange | positioned on the upper and lower sides of the foamable slurry sheet S2, for example, in addition to this, the several ventilation unit 39,41 is a foamable slurry sheet. A plurality of the drying devices 9 may be arranged in the width direction of S2. In this case, the heaters 51 and 53 of the blower units 39 and 41 arranged in the width direction so that the temperature of the gas blown toward the upper surface S2a and the lower surface S2b of the foamable slurry sheet S2 gradually changes in the width direction. By individually controlling, a porous green sheet G in which the porosity gradually changes in the width direction can be easily manufactured.

  Even in this configuration, the upper surface S2a and the lower surface S2b of the foamable slurry sheet S2 are heated evenly by blowing the heated gas, so that the heating temperature distribution in the width direction of the foamable slurry sheet S2 is not uniform. It is possible to prevent the bubbles from being continuous, and to smoothly change the size of a large number of bubbles distributed in the width direction in the porous green sheet G.

  Furthermore, in the said embodiment, although the porous body manufacturing apparatus 1 which manufactures the porous green sheet (porous body) G was demonstrated, the porous body manufacturing apparatus 1 further includes the said porous green sheet G, for example. It may be configured to produce a porous fired body (porous body) by degreasing and firing.

It is a schematic sectional drawing which shows the porous body manufacturing apparatus which concerns on one Embodiment of this invention. FIG. 2 is a schematic cross-sectional view showing a foaming device in the porous body manufacturing apparatus of FIG. 1. In the porous body manufacturing apparatus of FIG. 1, it is a schematic sectional drawing which shows a drying apparatus. It is a model figure which shows typically the cross section of the porous green sheet manufactured with the porous body manufacturing apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Porous body manufacturing apparatus 3 Carrier sheet 7 Foaming apparatus (foaming means)
9 Drying equipment (drying means)
15 Humidification heating container 15a Conveying inlet 15b Conveying outlet 17 Storage tank 19 Circulating mechanism 21 Water temperature adjusting heater 33 Sheet heating heaters 39, 41 Blow unit (heating unit)
G Porous green sheet (porous material)
S2 Expandable slurry sheet S2a Upper surface S2b Lower surface W Water

Claims (5)

A porous body production apparatus for producing a porous body having a three-dimensional network structure by foaming and drying a foamable slurry sheet containing at least an inorganic powder, a foaming agent and a binder while being conveyed by a carrier sheet,
Foaming means for foaming the foamable slurry sheet conveyed by the carrier sheet so as not to be dried under high humidity conditions, and drying means for heating and drying the foamable slurry sheet foamed in the foaming means. Prepared,
The drying means includes a plurality of heating units for heating the foamable slurry sheet disposed on the carrier sheet,
A plurality of the heating units are divided and arranged so as to individually heat at least the upper surface and the lower surface of the foamable slurry sheet disposed on the carrier sheet,
The porous body manufacturing apparatus, wherein the operation of each heating unit can be independently controlled so that the heating temperatures of the upper surface and the lower surface of the foamable slurry sheet by the heating unit are different from each other. A plurality of the heating units arranged on at least one of the upper surface side and the lower surface side of the foamable slurry sheet are arranged over the width direction of the foamable slurry sheet,
The operation of each of the heating units can be independently controlled so that the heating temperature distribution of the upper surface or the lower surface heated by the plurality of heating units gradually changes in the width direction. Item 2. The porous body production apparatus according to Item 1.   The said heating unit consists of a ventilation unit which blows the gas heated toward the upper surface or lower surface side of the said foamable slurry sheet, The porous body manufacturing apparatus of Claim 1 or Claim 2 characterized by the above-mentioned.   The foaming means has a transport inlet and a transport outlet through which the carrier sheet and the foamable slurry sheet can pass, and a humidification heating container capable of storing a predetermined amount of water below the transport inlet and the transport outlet, and the humidification A sheet heating heater provided in a heating container for heating the foamable slurry sheet, a storage tank having a water temperature adjustment heater for storing a larger amount of the water than the humidification heating container, and adjusting the temperature of the water; The porous body manufacturing apparatus according to any one of claims 1 to 3, further comprising a circulation mechanism that circulates the water between the humidification heating container and the storage tank. A porous body manufacturing method for manufacturing a porous body having a three-dimensional network structure by foaming and drying a foamable slurry sheet containing at least an inorganic powder, a foaming agent and a binder while being conveyed by a carrier sheet. ,
A foaming step of foaming so as not to dry the foamable slurry sheet under high-humidity conditions; and a drying step of drying the foamed slurry sheet,
In the drying step, the heating temperature is varied between the upper surface and the lower surface of the foamable slurry sheet disposed on the carrier sheet.

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