Heat exchanging device for powder, and method for manufacturing the same

To provide a heat exchanging device for powder, which is capable of suppressing as much as possible the compression force applied to an object to be processed and reducing the manufacturing man-hour (time), while ensuring the piston flowability of the object to be processed. In order to achieve this object, the present invention is a heat exchanging device for powder, which is configured such that a shaft 13 is rotatably supported within a horizontally long casing 1, that a plurality of heat exchangers 30 are disposed at predetermined intervals on the shaft, and that a heat exchanging medium is supplied into the heat exchangers via the shaft, wherein the heat exchangers 30 are formed as substantially hollow disk-shaped heat exchangers each having a notched recess 31 directed to a center from a circumferential edge.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. national stage application of PCT/JP2007/070985 filed on Oct. 23, 2007, and claims priority to, and incorporates by reference, Japanese Patent Application No. 2006-290359 filed on Oct. 25, 2006.

TECHNICAL FIELD

The present invention relates to a heat exchanging device for drying, heating or cooling powder, and a method for manufacturing the heat exchanging device. The concept of “powder” in this specification contains not only powder, but also particle or granule and their mixture.

BACKGROUND ART

As a heat exchanging device for drying, heating or cooling a variety of powder, an indirect heat transfer agitating type dryer is known.

The one disclosed in, for example, Japanese Examined Patent Application Publication No. S48-44432 (Patent Literature 1, hereinafter) is known as such an indirect heat transfer agitating type dryer. The disclosed device is so configured that a shaft is rotatably supported within a horizontally long casing, that a plurality of heat exchangers are disposed at predetermined intervals on the shaft, and that a heat exchanging medium is supplied into the heat exchangers via the shaft. In this device the powder is dried (heated, cooled) by indirect heat transfer from the shaft and heat exchangers.

Here, the heat exchanger disclosed in Patent Literature 1 uses a wedge-shaped hollow rotating body50, as shown inFIG. 14. This wedge-shaped hollow rotating body50is formed by bringing two pieces of fan-shaped plate materials51,51into contact with each other at one side of their ends while separating the plate materials51,51at the other side to block the periphery thereof with plate materials52,53. Therefore, the hollow rotating body50is shaped into a wedge in which a front end part54at the leading end in a rotation direction forms a line, while a rear end part55at the rear end in the rotation direction forms a surface. Two of the wedge-shaped hollow rotating bodies50are then disposed as a pair with certain gaps A, A therebetween so as to be symmetric with each other with respect to a shaft60, as shown inFIG. 15. The two wedge-shaped hollow rotating bodies50form a pair and a plurality of the pairs are disposed at predetermined intervals in an axial direction of the shaft60.

The disclosed in Patent Literature 1 had the following excellent characteristics:

(1) Small installation area and size.

(2) Large heat transfer coefficient and high heat efficiency.

(3) Self-cleaning effect achieved by the wedge-shaped hollow rotating bodies.

(4) The temperature of an object to be processed and the time for processing it can be controlled easily.

(5) Powder with high moisture content can be processed.

(6) Excellent piston flowability (transferability) of the object to be processed.

However, the device described in Patent Literature 1 has such a problem that when the object to be processed is brittle and fragile, it receives a compression force from the wedge-shaped hollow rotating bodies50serving as the heat exchangers and thereby becomes pulverized.

Also, a problem in producing the shaft provided with the wedge-shaped hollow rotating bodies is that it requires an enormous amount of time due to the shape of the shaft with the rotating bodies. In other words, the wedge-shaped hollow rotating body50is created by disposing the two pieces of fan-shaped plate materials51,51, isosceles triangular plate material52, and trapezoidal plate material53in the manner shown inFIG. 16and welding the entire periphery of the abutting parts. Therefore, when forming a single heat exchanger, the welding process comprises a plurality of processes, and automation of the welding operation is difficult. Furthermore, it is difficult to fix the obtained heat exchanger to the shaft60. This is because, in order to secure the heat exchangers to the shaft60, first a plate material61formed with notches which are substantially the same shape as a part (opening part) of each heat exchanger that is in contact with the shaft60, is lined (welded) on the entire outer peripheral surface of the shaft60, and thereafter the plate material61, the shaft60and the parts of the heat exchangers abutting on the plate material61and the shaft60need to be welded at the entire periphery of the abutting sections. In such welding, the welding methods of each layer need to be changed. For this reason, the problem of the device described in Patent Literature 1 is that an enormous amount of time is required in forming the heat exchangers.

There is also a device in which a plurality of hollow disks are simply attached to a shaft as heat exchangers. Such a hollow disk-shaped heat exchanger, however, cannot ensure the piston flowability of the object to be processed, which is an excellent characteristic of the wedge-shaped hollow rotating body disclosed in Patent Literature 1. The reason is because, as shown inFIG. 15, the piston flowability of the object to be processed can be secured for the first time by allowing the object to be processed to pass regularly through the gaps A, A of the two wedge-shaped hollow rotating bodies50,50attached to the shaft60.

Here, the piston flowability are important factors for realizing the first-in-first-out phenomenon of the object to be processed and obtaining residence time, heat history, and reaction time to keep each particle of the powder even, and are important attributes of the heat exchanging device in order to maintain the consistent quality of the object to be processed.

The gaps A, A described in Patent Literature 1 function to transfer powder layer formed at the nearest part (upstream side) within the device from a raw material feeding port side to a product discharge side. At this moment, the wedge-shaped hollow rotating body50itself does not have an extrusion force that a screw has. For this reason, in this device, the powder is sliced regularly, such as twice per rotation, in order to be transferred by the gaps A, A simply using the pressure of the powder. Therefore, back mixing or short pass seldom occurs on the powder in this device, so that “the first-in-first-out phenomenon” can be ensured and the piston flowability can be realized. On the other hand, in the case of the device in which simple hollow disk-shaped heat exchangers are attached to the shaft, the object to be processed is transferred from a gap between a casing and each heat exchanger to a downstream side. As a result, the back mixing or short pass phenomenon occurs where a part of the powder layer in the vicinity of the shaft remains in its position, while a part of the same near the casing moves rapidly, whereby the piston flowability cannot be realized.

The present invention has been contrived in view of the above problems of the background art. An object of the present invention is to provide a heat exchanging device for powder, which is capable of suppressing the compression force applied to an object to be processed, as much as possible, while ensuring the piston flowability of the object to be processed, and reducing the manufacturing man-hour (time), as well as a method for manufacturing the heat exchanging device.

DISCLOSURE OF THE INVENTION

In order to achieve the above object, a heat exchanging device for powder according to the present invention is a heat exchanging device for powder, which is configured such that a shaft is rotatably supported within a horizontally long casing, that a plurality of heat exchangers are disposed at predetermined intervals on the shaft, and that a heat exchanging medium is supplied into the heat exchangers via the shaft, wherein at least some of the plurality of heat exchangers are formed as substantially hollow disk-shaped heat exchangers each having a notched recess directed to a center from a circumferential edge.

According to the heat exchanging device for powder according to the present invention, at least some of the plurality of heat exchangers disposed on the shaft are formed into a substantially hollow disk shape with little resistance, whereby the compression force applied to an object to be processed as much as possible. Therefore, even when the object to be processed is brittle and fragile, pulverization thereof can be prevented. Also, because each heat exchanger has a notched recess directed to a center from a circumferential edge, the object to be processed can be allowed to pass through from the notched recess, and the piston flowability of the object to be processed can be ensured. In addition, because each heat exchanger is configured simply into a substantially hollow disk shape, the manufacturing man-hour (time) can be reduced and the welding operation can be automated easily.

Here, in the heat exchanging device for powder according to the present invention, a preferred embodiment of the present invention is to form the notched recess of the each heat exchanger into a smooth curve. Another preferred embodiment of the present invention is to provide two or more of the notched recesses to each heat exchanger at regular intervals in a circumferential direction of each heat exchanger. Yet another preferred embodiment of the present invention is to dispose the plurality of heat exchangers on the shaft, with the notched recesses of the heat exchangers pointing in the same direction. Yet another preferred embodiment of the present invention is to provide a central part of each of the heat exchangers with a projection bulging in a horizontal direction as viewed in side elevation, to form each of the heat exchangers into a substantially hollow disk shape in which a leading end of the projection is formed with an opening part, and to dispose the plurality of heat exchangers thus formed on the shaft by inserting the shaft into the opening part. An additional preferred embodiment of the present invention is to configure the projection of each of the heat exchangers to have a smoothly curved concentric circle.

In order to achieve the above object, a method for manufacturing a heat exchanging device for powder according to the present invention has: a step of forming substantially circular plate-shaped plate materials having a notched recess directed to a center from a circumferential edge and substantially circular opening parts at centers of the plate materials; a step of bending a rim part of each of the substantially circular plate-shaped plate materials in one direction and a rim of each of the central opening parts in another direction; and a step of joining the two substantially circular plate-shaped plate materials that are bent in a direction in which the rim parts are abutted on each other, and welding the circular plate-shaped plate materials at the abutted rim parts to produce substantially hollow disk-shaped heat exchangers, and integrally welding the adjacent heat exchangers to a shaft at a position where leading ends of opening parts of the heat exchangers are abutted on each other, to fix the heat exchangers to the shaft.

According to the method for manufacturing a heat exchanging device for powder according to the present invention, when forming the heat exchangers, the heat exchangers are welded at one section, which is the rim part where the two bent and substantially circular plate-shaped plate materials are abutted on each other (one weld line). Therefore, this operation can be performed in a short time, and the welding operation can be automated extremely easily. Moreover, because the adjacent heat exchangers are integrally welded to the shaft at the leading ends of the opening parts of the heat exchangers, when securing the heat exchangers to the shaft. Therefore, the welding time can be significantly reduced. In this case as well, the welding operation can be automated extremely easily, because there is one weld line.

Here, in the method for manufacturing a heat exchanging device for powder according to the present invention, a preferred embodiment of the present invention is to configure the step of producing the heat exchangers and fixing the heat exchangers to the shaft, with the step of joining the two bent and substantially circular plate-shaped plate materials in the direction in which the rim parts are abutted on each other and welding the circular plate-shaped plate materials at the abutted rim parts, the step of inserting the shaft into the opening parts of the substantially hollow disk-shaped heat exchangers produced in the welding step and disposing the plurality of heat exchangers on the shaft, and the step of integrally welding the disposed adjacent heat exchangers to the shaft at the position where the leading ends of the opening parts of the heat exchangers are abutted on each other. Another preferred embodiment of the present invention is to configure the step of producing the heat exchangers and fixing the heat exchangers to the shaft, with the step of changing alternately the orientations of the bent substantially circular plate-shaped plate materials and inserting the shaft into the opening parts to dispose the plurality of bent substantially circular plate-shaped plate materials on the shaft, and the step of successively performing welding at the rim parts where the disposed substantially circular plate-shaped plate materials are abutted on each other and integral welding of the plate materials with the shaft at the part where the leading ends of the opening parts are abutted on each other. An additional preferred embodiment of the present invention is to provide a trimming step of adjusting the shape and size of each of the bent substantially circular plate-shaped plate materials, subsequent to the bending step.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the heat exchanging device for powder according to the present invention and of a method for manufacturing for the heat exchanging device are described hereinafter in detail.

FIG. 1is a side view showing a part of a heat exchanging device for powder according to the present invention.FIG. 2is an enlarged cross-sectional view of a part taken along line X-X ofFIG. 1.

In these figures, reference numeral1represents a casing of the heat exchanging device, which consists of a relatively horizontally long container. This casing1is slightly inclined by a support2according to need. As shown inFIG. 2, the cross section of the casing1is in the shape of a bowl defined by two circular arcs. At a central bottom part of the bowl, a raised body3formed by the circular arcs runs in a front-to-rear direction of the casing1, in the form of a convex. A heat exchange jacket4is provided on substantially the entire surface of bottom and side surfaces of the casing1.

As shown inFIG. 1, a supply pipe5and discharge pipe6for supplying and discharging a heat exchanging medium are connected to the heat exchange jacket4. A rear end bottom part of the casing1is provided with a discharge port7for discharging an object to be processed, and a cover8is attached to an upper surface of the casing1by a bolt of the like. A front end part of the cover8is provided with a feed port9for feeding the object to be processed, the front end part and rear end part of the cover8with carrier gas inlet ports10,11respectively, and a central part of the cover8with a carrier gas discharge port12.

Also, two hollow shafts13,13run parallel through in the front-to-rear direction of the casing1. These hollow shafts13,13are supported by bearings14,14and15,15provided in the front and rear parts of the casing1, so as to be freely rotatable. A front part of each of the shafts13,13is provided with a gear16,16. The gears16,16are meshed with each other so that the shafts13,13rotate in the directions opposite to each other. One of the shafts13is provided with a sprocket17. The rotation of a motor (not shown) is transmitted to the shafts13,13via a chain (not shown) meshed with this sprocket17.

Supply pipes19,19for supplying the heat exchanging medium are connected respectively to front ends of the shafts13,13via rotary joints18,18. Similarly, discharge pipes21,21for discharging the heat exchanging medium are connected respectively to rear ends of the shafts13,13via rotary joints20,20. As shown inFIG. 2, each of the shafts13,13is provided with a partition plate22,22dividing the inside of the shaft13into two in an axial direction. The inside of each shaft13is divided by the partition plate22into a primary chamber23and a secondary chamber24. The primary chamber23is communicated with a front part of the shaft13, while the secondary chamber24is communicated with a rear part of the shaft13. In this state, although not particularly shown, the above configurations can be realized by sealing a front end of the secondary chamber24with a semicircular end plate in the front part of the shaft13and sealing a rear end of the primary chamber23with a semicircular end plate in the rear part of the shaft13.

In addition, in each of the shafts13,13, a plurality of heat exchangers30,30. . . are disposed at regular intervals. Each of the heat exchangers30is formed into a thin and substantially hollow disk shape, with both plate surfaces disposed in parallel. Specifically, as shown inFIGS. 3 to 5, the heat exchanger30has two notched recesses31,31that are directed to the center from respective circumferential edges37,37and placed symmetrically, and, in the center38of the heat exchanger30, concentric projections32,32that are gently curved in a horizontal direction as viewed from the side. Opening parts33,33are formed on leading ends of the projections32,32, respectively. It is preferred that the heat exchanger30be formed into a so-called cocoon that is relatively thin and flattened out, and that each of the notched recess31be configured into a smooth curve, as shown.

Note that the number of the notched recesses31formed in the heat exchanger30is not limited to two. Specifically, each of the notched recesses31may have an opening area that is large enough to allow the passage of the object to be processed. In other words, the areas of the notched recesses31(the parts with dotted diagonal lines inFIG. 3) may be equal to the areas of the two fan-shaped gaps A, A that are formed between the two wedge-shaped hollow rotating bodies50,50attached to the same perpendicular surface of the shaft60of the conventional technology shown inFIG. 15. Therefore, the number of the notched recesses31may be one, three, or more. However, when the number of the notched recesses31is two or more, it is preferred that the notched recesses31be disposed at regular intervals in a circumferential direction. Moreover, several types of opening area adjusting members (not shown) with different sizes that can be detachable with respect to the notched recesses31may be prepared to adjust the areas of the notched recesses31on the basis of the property of the object to be processed.

A plurality of the heat exchangers30having the above configuration are disposed at regular intervals in each shaft13such that the notched recesses31of the respective heat exchangers30are arranged in the same direction. The distance between the heat exchangers is ensured by causing the leading ends of the projections32,32of the adjacent heat exchangers30,30to abut on each other when the shaft13is inserted into the opening parts33of the respective heat exchangers30. Then, when the number of the notched recesses31of each heat exchanger30is two, the two shafts13,13are disposed with their phases shifted such that the positions of the notched recesses31,31are shifted by 90 degrees, as shown inFIG. 2.

Note that the number of shafts13is not limited to two and may be, for example, four or more, or even one (uniaxial). Also, heat exchangers to be disposed on each shaft13may all be the abovementioned substantially hollow disk-shaped heat exchangers30, but they may be combined appropriately with the conventional wedge-shaped heat exchangers50and attached to the shaft13, in accordance with the property of the object to be processed (thermal intensity change). Specifically, the substantially hollow disk-shaped heat exchangers30may be attached to only the front half part of the shaft13(the feed port9side), only the rear half part of the shaft13(the discharge port7side), or only the middle part of the shaft13. Conversely, the conventional wedge-shaped heat exchangers50may be attached to any of above mentioned each part. The proportion of each of the attached parts can be changed appropriately on the basis of the property of the object to be processed.

As shown inFIG. 3and the like, a scraping blade34is attached to an outer peripheral part on the rear side in the rotation direction of the heat exchangers30. This scraping blade34is attached to each of the heat exchangers30. However, a bridge-blade (not shown) may be laid between two or more of the adjacent heat exchangers30,30and attached in accordance with the property of the object to be processed. In this case, it is necessary to set the distance between the shafts13,13so that the transfer blade between the heat exchangers30,30of one of the shafts13does not collide with the heat exchangers30of the other shaft13.

As shown inFIG. 5, a partition plate35is attached to the inside of each heat exchanger30. This partition plate35divides an internal space36of the heat exchanger30to form a flow in which the heat exchanging medium flowing from the primary chamber23of the abovementioned shaft13into the internal space36of the heat exchanger30via a continuous hole25circulates through the internal space36in a fixed direction and flows out to the secondary chamber24of the shaft13via a continuous hole26. Note that in the case of a relatively small device, there may be one partition plate35. Conversely, in the case of a large device, a plurality of partition plates35may be provided to divide the internal space36of the heat exchanger30smaller, and similarly the continuous holes25,26for communicating the internal space36with the primary chamber23and the secondary chamber24of the shaft may be provided.

The heat exchanger30having the above configuration can be created as follows.

First, a plate material40shown inFIGS. 6 and 7is the one obtained before bending is performed thereon. The shape and size of this plate material40are determined in consideration of the finished shape and size of the heat exchanger30shown inFIGS. 3 to 5andFIG. 11. Specifically, this substantially circular plate-shaped plate material40has, at the center thereof, a substantially circular opening part41corresponding to the opening part33. The substantially circular plate-shaped plate material40also has notched recesses42,42corresponding to the two notched recesses31,31, at symmetrical positions of a rim part of the plate material40.

The plate material40is then bent to create a molded article43shown inFIGS. 8 and 9. This bending can be performed by means of pressing using a mold constituted by a die (female mold) and punch (male mold). Specifically, a rim part44of the plate material40is bent approximately 30 degrees in one direction from an outer periphery at a position of a predetermined length (rightward inFIG. 9). In a central part of the plate material40, the opening part41is pushed and expanded to the size of the opening part33of the product size and caused to bulge concentrically in the other direction (leftward inFIG. 9) at a relatively large curvature radius, to process the projection32.

This processing may be performed at once with a pair of molds or performed separately on the rim part and the central part using different molds. It is preferred that the pressing be performed twice in order to form the molded article43accurately without deformation. In this case, it is preferred that the central bulging projection32be processed first. Moreover, the molded article43may be formed more accurately by roughly cutting a plate material into the shape of the plate material40in consideration of the finished shape and size of the heat exchanger30first, pressing this plate material40to process the projection32, bending the rim part44, and thereafter trimming the rim part44and the projection32. In this case, the opening41may or may not be provided in the center of the plate material40in advance.

Next, the created two molded articles43,43are joined together in a direction in which the rim parts44,44are abutted on each other, as shown inFIG. 10, and the entire periphery of the abutted rim parts44,44is welded. Then, as shown inFIG. 11, the heat exchanger30having thin and substantially hollow disk shape with both plate surfaces disposed in parallel is created. At this moment, the partition plate35dividing the internal space36of the heat exchanger30is also attached to the inside by means of welding and the like.

Subsequently, the shaft13is inserted into the opening part33of the created heat exchanger30, and the plurality of heat exchangers30,30. . . are disposed on the shaft13. The leading ends of the projections32,32of the respective adjacent heat exchangers30,30disposed on the shaft13are abutted on each other, and the entire periphery of the abutted projections32,32is welded, as shown inFIG. 12. Consequently, the abutted part between the adjacent heat exchangers30,30is welded and secured, and the heat exchangers30are welded and secured to the surface of the shaft13. Then, the scraping blade34is attached to an appropriate part of the heat exchangers30by means of welding or the like, and the shaft13disposed with the plurality of heat exchangers30,30. . . at predetermined intervals is disposed within the casing1, as shown inFIG. 13, to create the heat exchanging device.

Unlike the configuration described above, it is possible to adopt a manufacturing method in which the directions of the molded article43is changed without welding the created molded article43, the shaft13is inserted into the opening part33of the molded article43, whereby the plurality of molded articles43,43. . . are disposed on the shaft13, thereafter welding of the rim parts44,44where the molded articles43,43of the shaft are abutted on each other, and integral welding of the leading end parts of the projections32,32and the shaft13are performed successively, to create the substantially hollow disk-shaped heat exchanger30and to secure the heat exchanger30to the shaft13.

When producing the heat exchanger30of the present invention, it is only necessary to perform the welding in one section, which is the rim parts44,44where the created two molded articles43,43are abutted on each other (one weld line). Therefore, this operation can be performed in a short time, and the welding operation can be automated extremely easily. Also, when securing the heat exchanger to the shaft13, not only is it possible to weld and secure the heat exchangers30,30to each other, but also the two heat exchangers30,30can be welded and secured to the shaft13simultaneously, by performing the welding along the leading end of the projection33at which the adjacent heat exchangers30,30are abutted on each other. As a result, the welding time can be significantly reduced. In this case well, the welding operation can be automated extremely easily, because there is one weld line. Furthermore, when manually welding the conventional wedge-shaped heat exchanger50to the shaft60, multi-layer welding had to be performed, the welding methods of each layer need to be changed as mentioned above. However, when welding the heat exchanger30of the present invention to the shaft13automatically, single-layer welding can be accomplished by selecting an appropriate welding condition, and, as a result, the welding time can be reduced. In addition, when creating the conventional wedge-shaped heat exchanger50itself, multi-layer welding was similarly performed in order to weld the part where the plate materials are abutted on each other. However, when creating the heat exchanger30of the present invention, single-layer welding can be accomplished by conducting automatic welding, and, as a result, the welding time can be reduced in the same manner. Also, in the present invention the projections32of the heat exchanger30function as the plate material61(lining) that are required in attaching the conventional wedge-shaped heat exchanger50to the shaft60. Therefore, the amount and number of materials can be cut and the processing man-hour can be reduced.

Next is described how the powder is dried using the heat exchanging device of the present invention.

First, the powder, which is the object to be processed (powder or particle), is continuously supplied into the casing1in a constant amount through the feed port9of the heat exchanging device according to the present invention.

At this moment, a heating medium of a predetermined temperature, such as steam or hot water, is circulated through the jacket4to heat the casing1to a constant temperature. The two shafts13,13are rotated by the motor via the sprocket17and gears16,16. The heating medium, such as steam or hot water, is fed to the shafts13,13by the rotary joints18,18. The heating medium fed to each shaft13flows from the primary chamber23of the shaft13into the internal space36of the heat exchanger30and heats the heat exchanger30. The heating medium is then discharged from the discharge pipes21of the heat exchanging medium through the secondary chamber24of the shaft13and the rotary joint20of the rear part of the shaft.

The powder supplied into the casing1is heated by the casing1and heat exchanger30, and volatile matters evaporated from the powder are discharged along with carrier gas. Air, inert gas or the like, for example, is used as the carrier gas. The carrier gas supplied from the inlet ports10,11passes through an upper layer part within the casing1, is then discharged from the discharge port12along with the volatile parts evaporated from the powder (moisture, organic solvent, and the like) and appropriately processed outside the system. When the volatile matters are organic solvent, inert gas such as nitrogen gas is used as the carrier gas, and the discharge port12is coupled to a solvent condenser where the organic solvent is recovered. The carrier gas that passes through the condenser enters the casing1again through the inlet ports10,11, and the carrier gas is circulatorily used.

Flowability is generated in the powder by performing a mechanical agitating operation when the powder enters the casing1through the feed port9. The fed powder then gradually flows down the casing1due to the pressure generated as the powder fills the feed port9and the inclination of the casing1that is provided according to need. The powder then passes through the notched recesses31of the heat exchanger30and moves to the discharge port7.

The powder is dispersed by the rotation of the substantially hollow disk-shaped heat exchanger30perpendicular to a direction of travel, and at the same time the heat is exchanged so that the powder is dried efficiently. Also, because the heat exchanger30is formed into a substantially hollow disk to have little resistance, the compression force applied to the powder serving as the object to be processed at the time of dispersing can be suppressed as much as possible. Therefore, even when the powder is brittle and fragile, pulverization thereof can be prevented. Moreover, because the heat exchanger30has the notched recesses31directed to the center from respective circumferential edges, the powder can pass through the notched recesses31, and the piston flowability can be secured. Therefore, the powder that is dried after an even residence time is smoothly fed toward the discharge port7and discharged from the discharge port7.

The above has described the embodiments of the heat exchanging device for powder according to the present invention and of the method for manufacturing the heat exchanging device according to the present invention, but the present invention is not limited to these embodiments, and, of course, various modifications and changes thereof can be made within the scope of the technical concept of the present invention that is described in the patent claims.

A plurality of the heat exchanging devices can be coupled together in series, when the degree of dryness of the object to be processed needs to be enhanced. In addition, the shaft disposed with the heat exchangers may be added more and provided in parallel, when the amount of throughput needs to be increased.

The device of the present invention can be suitably used for drying a substance serving as the object to be processed and having a relatively small amount of evaporation, finish-drying the powder that is, for example, previously dried (powders of polypropylene, PVC, acrylic resin and the like), drying a synthetic resin chip (polyester, nylon and the like) having a little initial moisture, and drying a brittle and fragile powder an SAP (high water-absorption resin) surface reformed item, graphite granulated product, health food granules, and the like. The device of the present invention can also be used for cooling a heated and reacted substance (various inorganic substances and organic substances), reacting and the like.

INDUSTRIAL APPLICABILITY

The heat exchanging device for powder according to the present invention is used for drying, heating, cooling, or reacting powder material in a wide range of fields including synthetic resins, food products and chemical products.