JP4909640B2 - Superheated steam dryer - Google Patents

Description

  The present invention relates to a superheated steam drying apparatus for continuously drying an object to be dried in a batch circuit system in a closed circuit system of atmospheric superheated steam.

  Conventionally, as a method for drying a material to be dried such as a raw material or a residue, a hot air drying method in which outside air is introduced and heated to raise the temperature to hot air, and the moisture of the material to be dried is vaporized and evaporated by this heat has been mainly used. . The hot air drying method is a method of moving moisture from the material to be dried into the hot air and drying it, and in order to prevent pollution and effectively use heat, use a technology that cools, dehumidifies and reheats with a heat exchanger, In many cases, hot air is circulated, and a part is heated and sucked, and a part is discharged.

  However, the hot air drying method has been difficult to treat odor of exhaust gas generated in large quantities. The hot air drying method generally uses a high temperature at the initial stage in the drying process and a low temperature of about 80 ° C. in the latter stage in order to prevent the quality of the material to be dried from being denatured by heat. Since it progresses from the surface of the object to be dried and a hard dry cortex is formed on the surface, the internal drying is inhibited and the quality of the object to be dried is reduced. Furthermore, the hot-air drying method has a problem that the temperature of the material to be dried does not rise above the wet bulb temperature when water is evaporated during drying, and thus, complete sterilization and sterilization are not performed.

  On the other hand, the high-temperature and high-humidity drying method, which is dried at a high temperature (400 to 600 ° C.) and with high-humidity hot air, can continuously dry a large amount of an object to be dried, as compared with the conventional hot-air drying method, By using high-temperature, high-humidity hot air close to a water vapor atmosphere, the drying speed is fast and the drying apparatus can be miniaturized.

  However, the high-temperature and high-humidity drying method produces a hard dry cortex on the surface of the material to be dried, which not only causes deterioration of the quality of the material to be dried together with oxidation of the surface, but also causes moisture to evaporate during drying. Since the temperature of the object to be dried does not rise above the bulb temperature, there has been a problem that complete sterilization and sterilization cannot be performed. Further, the high temperature and high humidity drying method has a problem that the material to be dried tends to be denatured at the start and end of the operation of the drying process. Furthermore, since the high-temperature and high-humidity drying method is semi-closed circuit drying, it is difficult to oxidize the object to be dried and to treat the exhaust gas odor by inflow of air into the dryer.

Therefore, without discharging the odor generated from the object to be dried to the outside of the drying apparatus, while maintaining the quality of the object to be dried, the object to be dried can be sterilized and sterilized, and the inside of the object to be dried can be dried. Furthermore, a continuous normal pressure superheated steam drying method and apparatus that are energy saving and low running cost is disclosed (Patent Document 1).
JP 2002-62044 A

  However, according to Patent Document 1, the material to be dried is input from the input hopper and is discharged from the exit chamber when the drying process is completed, and the large mass is discharged as a dry product made into a small mass. Is. For this reason, although it can use for a specific to-be-dried material, it could not be used for various to-be-dried materials. For this reason, the apparatus which can be used for various to-be-dried objects and can dry efficiently is desired.

  In addition, since the apparatus is started up after the object is installed in the apparatus, the amount of condensation on the surface of the apparatus increases due to contact with the object to be dried in a state where the water vapor is wet. Furthermore, since the inside of the apparatus is replaced with air each time a product is taken out, there is a problem that it takes time to restart the apparatus.

  The subject of this invention is providing the superheated steam drying apparatus which can dry-process various to-be-dried objects and can perform a drying process efficiently.

  In order to solve the above problems, according to the present invention, a superheated steam supply means for supplying superheated steam, a drying section for drying a material to be dried in a superheated steam atmosphere by introducing superheated steam, It is configured to store dry matter and be movable inside and outside the drying unit, and stores the material to be dried at a first position where at least a part of the main body is outside the drying unit. A superheated steam drying apparatus is provided that includes, in a second position moved to, a storage unit that introduces superheated steam introduced into the drying unit into the main body and dries the material to be dried.

  In the superheated steam drying apparatus of the present invention, more specifically, the storage unit includes a steam inlet for introducing the superheated steam introduced into the drying unit into the main body, and a steam for discharging the superheated steam introduced into the main body. The superheated steam introduced into the drying section is discharged from the drying section without being introduced into the storage section when the storage section is in the first position and the steam inlet and the steam outlet are closed. When the storage unit is in the second position, the steam inlet and the steam outlet are opened, and the superheated steam introduced into the drying unit is introduced into the storage unit and then discharged from the drying unit. can do.

  Further, at least one of the drying part and the storage part is formed with a partition part for partitioning the circulation path part of the superheated steam and the non-circulation path part, and when the storage part is at the first position, the steam introduction port and the steam discharge port are provided. The partition portion is positioned on the non-circulation path section side of the drying section to be closed, and the storage section is in the second position and the water vapor inlet and the water vapor discharge port are positioned on the circulation path section side of the drying section by the partition section and opened. It can be configured to be in a state.

  The storage section may have a structure in which a water vapor inlet and a water vapor outlet are formed in a peripheral surface parallel to the moving direction. The drying section is provided with a drying section steam inlet for introducing superheated steam and a drying section steam outlet for discharging superheated steam, and when the storage section is at the second position, the steam inlet, steam outlet of the storage section The drying unit water vapor inlet and the drying unit water vapor outlet of the drying unit can be arranged in a straight line.

  Further, the storage unit is provided with an openable / closable portion that can be opened and closed at the first position, and the openable / closable portion can be opened and closed to allow the material to be dried to be taken in and out.

  The superheated steam supply means is provided with a circulation means for circulating the superheated steam introduced and discharged to the drying section to the drying section again, a steam supply section for supplying steam, and a superheat section for superheating the steam and superheated steam. It can be configured.

  Furthermore, the superheated steam drying apparatus of the present invention can be configured to include surplus steam discharging means for discharging surplus steam accompanying the evaporation of moisture of the material to be dried that is stored in the storage unit and dried.

  Moreover, it can also be set as the structure provided with the pressure detection means which detects the pressure in a drying part, and the pressure adjustment means which adjusts the pressure in a drying part based on the pressure detection result by this pressure detection means.

  The superheated steam drying apparatus of the present invention is configured so that a storage section for drying an object to be dried (object) can be moved in and out of the drying section, and can be circulated by bypassing the superheated steam. For this reason, the apparatus can be started up in a state where the superheated steam is circulated in advance before the drying process, and an object can be charged and taken out without replacing the inside of the apparatus with air. Therefore, the drying process can be performed in a short time. Moreover, the work at the time of preparation and removal of the object is easy. Since the superheated steam is circulated in advance, the steam can be brought into contact with the object in a dry state, and the influence of moisture on the object can be minimized. In addition, food and food waste can be sterilized with drying.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments, and changes, modifications, and improvements can be added without departing from the scope of the invention.

  FIG. 1 shows a superheated steam dryer 1 of the present invention. The superheated steam drying apparatus 1 is provided with a steam supply unit 8 that supplies water vapor, a circulation fan (circulation means) 7 that circulates water vapor, and a heater (superheater) 5 that superheats water vapor. The steam supply unit 8, the circulation fan 7, and the heater 5 constitute superheated steam supply means.

  The steam supply unit 8, the circulation fan 7, and the heater 5 are connected by a circulation pipe 12 to form a closed circuit, and the drying unit 2 is provided in the closed circuit. The drying unit 2 dries and sterilizes an object to be dried (object) in an atmosphere of superheated steam by introducing superheated steam from the superheated steam supply means. Furthermore, a storage unit 3 configured to store an object to be dried and move inside and outside the drying unit 2 is provided. As shown in FIG. 1, the storage unit 3 stores an object to be dried (target object) at a first position where at least a part of the main body is outside the drying unit 2, and the main body is positioned more than the first position. At the second position (see FIG. 3B) that has moved into the drying unit 2, the superheated steam introduced into the drying unit 2 is introduced into the main body to dry the material to be dried.

  The storage unit 3 includes a steam inlet 31 for introducing the superheated steam introduced into the drying unit 2 into the main body, and a water vapor discharge port 32 for discharging the superheated steam introduced into the main body. In the first position, the steam inlet 31 and the steam outlet 32 are closed, and the superheated steam introduced into the drying unit 2 is discharged from the drying unit 2 without being introduced into the storage unit 3, and is stored in the storage unit 3. However, in the second position, the steam inlet 31 and the steam outlet 32 are opened, and the superheated steam introduced into the drying unit 2 is introduced into the storage unit 3 and then discharged from the drying unit 2. With such a configuration, by moving the storage unit 3, it is possible to introduce superheated steam into the storage unit 3 and dry the object to be dried in the storage unit 3.

  More specifically, the storage unit 3 is formed with a partition 25 that partitions the superheated steam circulation path 23 and the non-circulation path 24, and the drying unit 2 includes a drying unit steam inlet 21 and a drying unit. A water vapor outlet 22 is provided.

  The accommodating part 3 is formed in a cylindrical shape, and the water vapor inlet 31 and the water vapor outlet 32 are formed in a peripheral surface part (cylindrical part) 33 parallel to the moving direction. Furthermore, the storage part 3 is provided with an opening / closing part 34 that can be opened and closed at the first position. The opening / closing part 34 is formed as a front door, and the opening / closing part 34 can be opened and closed so that an object to be dried can be taken in and out.

  With such a configuration, when the storage unit 3 is in the first position, the water vapor inlet 31 and the water vapor outlet 32 are positioned in the non-circulation path 24 of the drying unit 2 by the partition unit 25 and are closed. Further, when the storage unit 3 is in the second position, the water vapor introduction port 31 and the water vapor discharge port 32 are opened by being positioned in the circulation path unit 23 of the drying unit 2 by the partition unit 25, and the water vapor introduction port 31 of the storage unit 3, The water vapor discharge port 32, the drying unit water vapor introduction port 21, and the drying unit water vapor discharge port 22 are arranged in a straight line, and superheated water vapor can be introduced into the storage unit 3 to dry and sterilize the material to be dried. The superheated steam obtained by drying the material to be dried is discharged from the discharge port 32.

  Further, the superheated steam drying apparatus 1 includes a steam supply unit 8 for supplying steam for introducing the above-described superheated steam, surplus steam discharge means 9 for discharging surplus steam accompanying moisture evaporation of the object to be dried, Includes pressure detection means not shown in FIG.

  The operation principle of the superheated steam dryer 1 will be described with reference to FIG. The steam supply unit 8, the circulation fan 7, and the heater 5 are connected by a circulation pipe 12 to form a closed circuit, and the drying unit 2 is provided in the closed circuit. The steam supply unit 8 is provided with a steam valve, and the steam valve can be opened to introduce water vapor into the apparatus, and the water vapor can be superheated by the heater 5. With such a configuration, the superheated steam circulates in the closed circuit, and the object to be dried stored in the storage unit 3 can be dried and sterilized. The surplus water vapor discharge means 9 is provided with a solenoid valve, and can discharge surplus water vapor accompanying water evaporation of the material to be dried. The steam supply unit 8 and the surplus steam discharge means 9 can be adjusted so that the superheated steam in the closed circuit becomes appropriate.

  The drying method by the superheated steam drying apparatus 1 of the present invention is mainly characterized in that an object to be dried is continuously dried in a batch system in a closed circuit system of superheated steam (100 to 400 ° C.). After sufficiently replacing the air in the circulation path with superheated steam, the storage unit 3 is slid into the drying unit 2 to introduce the material to be dried into the drying unit 2, and the superheated steam atmosphere in the drying unit 2 is changed. The product to be dried can be continuously dried batchwise while circulating the superheated steam so as to maintain a constant condition. In addition, by sliding the storage unit 3 in the direction outside the drying unit 2, the material to be dried after the drying process can be taken out in a state where the superheated steam is circulated without opening the superheated steam atmosphere.

  The drying method using superheated steam is a drying method using steam (dry steam) having a drying ability at a temperature higher than the saturated steam temperature. Water vapor is saturated water vapor at less than 100 ° C. and does not have a drying ability. However, when it reaches 100 ° C. or higher, it has a drying ability. The higher the temperature, the higher the drying speed, and the easier it is to dry the article. Here, the superheated steam is steam that has been heated to 100 ° C. or more while maintaining saturated steam evaporated at 100 ° C. at normal pressure.

  The feature of drying with superheated steam is that the drying part 2 can be dried while being filled with water vapor, so there is no formation of cortex due to oxidation of the material to be dried or hardening of the surface of the material to be dried, and the moisture evaporation period in which the product is preheated Since the product temperature is maintained at approximately 100 ° C., sterilization, sterilization, and enzyme deactivation can be performed up to the inside of the object to be dried.

  In the superheated steam device 1 of the present invention, since the heating medium gas is a closed circuit, it is possible to prevent or suppress the discharge of odor generated from the material to be dried to the outside of the drying device. While maintaining the quality of the dried product, the material to be dried can be sterilized and sterilized, and the inside of the material to be dried can be dried. Further, energy saving and low running cost are achieved.

  In the drying treatment in the present invention, it is important to continuously dry the material to be dried in an atmosphere in which almost 100% of superheated steam is occupied at normal pressure. Note that the atmosphere occupied by the normal pressure superheated steam has almost zero air partial pressure, and almost no air is present. In order to maintain such an atmosphere in the drying unit 2 under certain conditions and maintain an oxygen-free state continuously, it is important that the drying unit 2 has a minute positive pressure.

  For this reason, in this invention, it is preferable to reheat the superheated steam used for drying by the electric heater 5, and to recirculate it in the drying part 2, or to discharge | emit excess steam.

  In the present invention, water vapor may be directly introduced into the drying unit 2, but it is also possible to generate superheated steam from hot air and spray water.

  In the drying process of the present invention, it is important to perform the superheated steam of the heat medium gas in a closed circuit system. As a result, there is no inflow of air into the drying unit 2 or outflow of exhaust gas to the outside of the drying unit 2 during the drying process, so that the object to be dried is not oxidized by oxygen, and the odor generated from the drying unit 2 Therefore, it is possible to contribute to environmental improvement.

  The drying process will be further described with reference to FIGS. 3A, 3B, 4A, and 4B. First, in order to store an object to be dried in the storage unit 3, as shown in FIGS. 3A and 4A, a part of the main body of the storage unit 3 is at a first position where it is outside the drying unit 2. To do. In this first position, the water vapor inlet 31 and the water vapor outlet 32 of the storage unit 3 are located in the non-circulation path unit 24 of the drying unit 2, and the superheated steam introduced into the drying unit 2 is stored in the storage unit 3. It is not introduced and is in a state of bypass circulation. With the storage part 3 slid out in this way, the valves are closed and the circulation fan 7 and the heater 5 are started. Then, the steam valve (see FIG. 2) is opened to introduce water vapor into the circulation path. When the steam is superheated by the heater 5 and circulated by the circulation fan 7, and the inside of the circulation path is replaced by the superheated steam, the steam valve is closed.

  Next, the opening / closing part 34 provided on the outer side in the moving direction of the storage part 3 that is pulled out is opened as shown in FIG. 1 to store an object to be dried (object). When the object to be dried is stored, the main body of the storage unit 3 is set to the second position in the drying unit 2 rather than the first position, as shown in FIGS. 3 (b) and 4 (b). In this state, the water vapor inlet 31 and the water vapor outlet 32 are positioned in the circulation path 23 of the drying unit 2 by the partition 25, and the water vapor inlet 31, the water vapor outlet 32, and the drying unit water vapor inlet 21 of the storage unit 3. And the drying part water vapor | steam discharge port 22 is arrange | positioned linearly, superheated steam can be introduce | transduced into the accommodating part 3, and a to-be-dried object can be dried.

  Since the steam inlet 31, the steam outlet 32, the drying part steam inlet 21, and the drying part steam outlet 22 are arranged in a straight line, the superheated steam can be circulated efficiently. Moreover, since the partition part 25 which partitions the circulation path part 23 and the non-circulation path part 24 of superheated steam is formed in the accommodating part 3, by moving the accommodating part 3 to a 1st position and a 2nd position Even if a special opening / closing device is not installed at the water vapor inlet 31 and the water vapor outlet 32, they can be in a closed state and an open state. In addition, the partition part 25 can also be formed in the drying part 2.

  When the moisture of the material to be dried is low, it is preferable to open the steam valve and add water vapor in the circulation path. Moreover, the superheated steam drying apparatus 1 includes a pressure detection unit that detects the pressure in the drying unit 2 and a pressure adjustment unit that adjusts the pressure in the drying unit 2 based on the pressure detection result. Then, the solenoid valve is opened, and the pressure is controlled to be constant.

  When the drying process of the object to be dried is completed, the storage unit 3 can be slid and pulled out, and the opening / closing part 34 can be opened to take out the object to be dried. With the superheated steam held in the circulation path, the material to be dried can be taken out and charged.

  The second embodiment of the present invention will be described with reference to FIG. In the present embodiment, a shelf 41 for placing an object to be dried is provided in the storage unit 3 so as to be substantially perpendicular to the flowing direction of superheated steam. A plurality of shelves 41 may be provided in the storage unit 3. By comprising in this way, a to-be-dried object can be effectively dried by circulation of superheated steam. Thereby, it is also possible to dry-process a powdery or small lump to-be-dried material.

  A third embodiment of the present invention will be described with reference to FIG. In the present embodiment, a cylindrical rotating drum 42 that is concentric with the storage portion 3 is provided inside the storage portion 3 that is formed in a cylindrical shape. The material to be dried can be effectively dried by introducing the material to be dried into the rotating drum 42 and circulating the superheated steam while rotating the rotating drum.

  As described above, by changing the internal structure of the storage unit 3, it is possible to adopt a system such as a shelf type or a stirring type according to an object to be dried (object). Thereby, various drying objects can be dried.

  The superheated steam drying apparatus of the present invention can be used as a drying apparatus for various objects to be dried such as food, fertilizer and fuel. It can also be used for drying and sterilizing food, reusing unused resources such as food waste, and drying and sterilizing electronic parts and glass products.

It is a block diagram which shows 1st embodiment of the superheated steam drying apparatus of this invention. It is a principle diagram of a superheated steam dryer. It is a schematic block diagram which shows the operation | movement in a 1st position. It is a schematic block diagram which shows the operation | movement in a 2nd position. It is a schematic diagram which shows the principal part in a 1st position. It is a schematic diagram which shows the principal part in a 2nd position. It is a block diagram which shows 2nd embodiment of the superheated steam dryer of this invention. It is a block diagram which shows 3rd embodiment of the superheated steam drying apparatus of this invention.

Explanation of symbols

1: Superheated steam dryer, 2: Drying unit, 3: Storage unit, 5: Heater, 7: Circulation fan, 8: Steam supply unit, 9: Excess water vapor discharge means, 12: Distribution pipe, 21: Drying unit water vapor introduction Mouth, 22: Drying section steam outlet, 23: Circulating path section, 24: Non-circulating path section, 25: Partition section, 31: Steam inlet, 32: Steam outlet, 33: Circumferential section, 34: Opening / closing section, 41: shelf, 42: rotating drum

Claims (8)

Superheated steam supply means for supplying superheated steam;
By introducing the superheated steam, a drying unit for drying the material to be dried in a superheated steam atmosphere;
A steam inlet for introducing the superheated steam introduced into the drying section into the main body, and a steam outlet for discharging the superheated steam introduced into the main body, storing the material to be dried, The drying unit is configured to be movable in and out of the drying unit, and at least a part of the main body stores the object to be dried in a first position outside the drying unit, and the main body is in the drying unit than the first position. In the moved second position, the storage unit for introducing the superheated steam introduced into the drying unit into the main body and drying the material to be dried, and
A partition part that is formed in at least one of the drying part or the storage part and divides the circulation path part and the non-circulation path part of the superheated steam;
Pressure detecting means for detecting the pressure in the drying section;
Pressure adjusting means for adjusting the pressure in the drying unit based on the pressure detection result by the pressure detecting means,
The superheated steam is atmospheric superheated steam;
When the storage portion is in the first position, the water vapor inlet and the water vapor outlet are closed by the partition portion on the non-circulation path portion side of the drying portion, and are introduced into the drying portion. The superheated steam is discharged from the drying unit without being introduced into the storage unit,
In the second position, the water inlet and the water vapor outlet are positioned on the circulation path part side of the drying part by the partition part, and the storage part is opened and is introduced into the drying part. The superheated steam dryer is discharged from the drying unit after the superheated steam is introduced into the storage unit . The superheated steam drying apparatus according to claim 1 , wherein the storage portion has the steam introduction port and the steam discharge port formed in a peripheral surface portion parallel to a moving direction thereof. The drying section is provided with a drying section steam inlet for introducing the superheated steam, and a drying section steam outlet for discharging the superheated steam,
The water vapor inlet, the water vapor outlet, the drying part water vapor inlet of the drying part, and the drying part water vapor outlet are arranged in a straight line when the storage part is in the second position. Item 3. The superheated steam dryer according to Item 1 or 2 . The superheated steam according to any one of claims 1 to 3 , wherein the storage unit is provided with an openable / closable portion that can be opened and closed at the first position, and the openable / closable portion is opened and closed to take in and out the material to be dried. Drying equipment. The superheated steam supply means according to any one of claims 1 to 4 , wherein the superheated steam supply means is provided with a circulation means for circulating the superheated steam introduced and discharged to the drying section to the drying section again. Steam dryer. The superheated steam drying device according to any one of claims 1 to 5 , wherein the superheated steam supply means is provided with a steam supply unit for supplying steam. The superheated steam drying apparatus according to claim 6 , wherein the superheated steam supply means is provided with a superheater that superheats the steam and the superheated steam. The superheated steam drying device according to any one of claims 1 to 7 , further comprising surplus steam discharging means for discharging surplus steam accompanying the evaporation of moisture of the material to be dried which is stored in the storage unit and dried.

Images