JP2014070886A - Dehydration and concentration method and dehydration and concentration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a new dehydration and concentration method and a dehydration and concentration device capable of drying continuously an object to be processed under normal pressure and also substantially reducing a manufacturing cost of the device while cause of trouble of a compressor etc. is eliminated as much as possible.SOLUTION: A heat pump type processing device H is constituted such that after a thermal medium of low temperature discharged out of a heating device is increased in its temperature under application of a compressor 5, it is supplied again to the heating device and used in circulation form. Super heated steam S1 acting as carrier gas is supplied to a main body shell 10 so as to evaporate moisture from the object to be processed in a state that an inside part of the main body shell 10 is kept under a normal pressure and at the same time heat of the carrier gas including water steam evaporated from the object to be processed that is discharged out of an exhaust port 104 formed at the main body shell 10 is taken into the thermal medium.

Description

  The present invention relates to a method for drying and concentrating materials and liquid materials such as mud, cake, and granular materials, and an apparatus therefor, and more particularly, from a work to be processed discharged from an exhaust port in a conduction heat transfer dryer. The present invention relates to a drying / concentration method and apparatus for supplying the heat of a carrier gas containing evaporated water vapor as a drying heat source for an object to be processed.

  Recently, environmental conservation efforts have become popular, and companies have tried to reduce weight and prevent spoilage by drying general waste such as food waste and food processing residues and sewage sludge. In addition, recycling and disposal are performed. One of the apparatuses used for such drying is a heat pump type processing apparatus that supplies steam generated from the object to be processed as a heating source for the object to be processed. This apparatus is a direct pressure type (vapor recompression type). ).

Among them, the vapor recompression type drying / concentrating device H ′ provided with the conduction heat transfer type dryer 1 ′ has moisture (water vapor) evaporated from the object to be treated in the main body shell 10 ′ as shown in FIG. The carrier gas (S2 ′) containing is directly compressed by the compressor 5 ′ to raise the temperature, and this is supplied to a multitubular heating tube 11 ′ which is an example of a heating device. It becomes a drying heat source for the workpiece to be in contact with the outer surface (heat transfer surface).
In such a vapor recompression type apparatus, the size of the apparatus is almost equal to the difference between the temperature of the drying heat source (S5 ′) supplied to the multi-tube heating pipe 11 ′ and the temperature of the object to be processed. Since it is inversely proportional, the apparatus becomes large when the temperature difference is small, and if it is attempted to take a large temperature difference in order to eliminate this, the compression efficiency in the compressor 5 'decreases and the power consumption increases. Will end up. In addition, when a turbo compressor is used as the compressor 5 ', the efficiency becomes worse with a small one. Furthermore, if fine powder or corrosive volatile components scattered from the conduction heat transfer dryer 1 'enter the compressor 5', it may cause a failure of the compressor 5 ', the COD of the drain D, There are problems such as an increase in BOD. And since such various subjects have not been solved, the direct pressurization type steam recompression type heat pump type processing apparatus is practically not practically used.

Indirect pressurized vapor recompression heat pumps often use a refrigeration system that uses chlorofluorocarbon as a heat medium. This heat medium (refrigerant) has a low boiling point, a high pressure at a high temperature, and approaches a critical point, so that it is not suitable for use in a dryer. For example, the refrigerant R134a has a critical point of 101.1 ° C. and a critical pressure of 4.06 MPa.
In this system, a combination of a vacuum pump and a condenser (cooling heat exchanger) is usually used to remove water evaporated from the object to be processed (see, for example, Patent Document 3).
Here, if the exhaust capacity (vacuum reach) of the vacuum pump is high, the evaporation temperature of moisture from the object to be processed can be lowered, and the temperature difference with the heat medium (heated steam) to be indirectly heated can be increased. Heat can be promoted to improve the drying rate.
However, on the other hand, it is necessary to operate a series of systems from the dryer to the vacuum exhaust device under vacuum. The dryer becomes a vacuum dryer, which requires a sturdy body that can withstand external pressure and a special system for discharging the dried product.
The reason is to obtain a high degree of vacuum as described above, and to prevent leakage of outside air to a dryer or the like. Here, if the air leakage is not suppressed, the heat exchange capability of the condenser is lowered. For example, when the heat recovered by the condenser is to be recovered by a heat pump, the energy saving effect is impaired.
Therefore, in addition to the dryer, for example, the damper for discharging the dried product is a product that is dried to atmospheric pressure by intermittent opening and closing operation using a double damper type discharge device to suppress air intrusion. Need to be discharged. This double damper tends to bite a dry product, easily deteriorates the sealing performance, and easily increases the amount of air leakage. Moreover, regarding the apparatus shape, since the height dimension of the apparatus is large, it is necessary to increase the installation height of the entire drying facility.
In this way, a dryer that performs drying under vacuum requires a design that is rugged and less leaky, and that peripheral equipment must be based on a similar design philosophy. End up.
Of course, as disclosed in Patent Document 3, there is also a method of making a batch type vacuum dryer that does not require continuous discharge of the dried product from vacuum to atmospheric pressure, but the operation of starting (input of material to be dried, vacuum Exhaust and preheating) and stop operation (return from vacuum to atmospheric pressure, dry product discharge) are required. In addition, the moisture of the material to be dried in the dryer changes from high moisture to low moisture during one batch, and accordingly, the amount of water evaporation increases at the beginning of drying, decreases from the middle, and hardly evaporates at the end. . For this reason, the heat recovery amount of the evaporated water vapor as the heat pump system changes, and the start / stop time does not operate at all, so that energy-saving operation cannot be performed.
For the above reasons, there is no example of practical application of an indirectly pressurized vapor recompression heat pump with a conduction heat transfer dryer.

Therefore, the present applicant can configure the entire apparatus on a small scale, can continuously perform the drying / concentration operation of the object to be processed, can further reduce power consumption, and can be further condensed. A new vapor recompression heat pump type processing device that does not cause water contamination has been developed and has already been filed for a patent application. This invention has been evaluated and registered (see Patent Document 1). As shown in FIG. 5, the apparatus disclosed in Patent Document 1 is provided with a mist separator between a plurality of compressors 5 ′, and saturated steam at 100 to 120 ° C. is supplied to a multi-tube heating pipe 11. The body shell 10 'is evacuated to lower the boiling point temperature from the normal pressure, and the object to be treated and the drying heat source (S5') supplied to the multi-tube heating tube 11 ' The difference in temperature can be greatly increased to promote the evaporation of moisture from the object to be processed.
Subsequently, the present applicant has continued research and development on the vapor recompression type heat pump type processing apparatus and has attempted various improvements. Conventionally, as shown in FIG. Is used, based on the idea of using superheated steam S1 ', it is possible to continuously dry the workpiece under normal pressure and to greatly reduce the manufacturing cost of the apparatus. An invention has been devised and patent applications have already been filed (see Patent Document 2).
Further thereafter, the present applicant applies the above-described invention characterized in that superheated steam is used as a carrier gas to a heat pump processing apparatus of an indirect pressurization type steam recompression type that is different from the direct pressurization type steam recompression type. As a result, we started to develop a device that can solve the above-mentioned problems such as compressor failure.

Japanese Patent No. 4420737 Japanese Patent Application No. 2012-142757 Japanese Patent Laid-Open No. 04-281178

  The present invention has been made from such a background, and it is possible to continuously dry an object to be processed under normal pressure, and to greatly reduce the manufacturing cost of the apparatus. The technical issue is the development of a novel drying / concentration method and its apparatus, in which the causes of failure and the like have been eliminated without limit.

  That is, in the drying / concentration method according to the first aspect, a heating device is provided in the main body shell, and a continuous conduction transmission configured to evaporate water by bringing a workpiece into contact with the heat transfer surface of the heating device. In the drying / concentration method using the heat pump type processing apparatus provided with the heat dryer, the heat pump type processing apparatus raised the temperature of the heat medium discharged from the heating apparatus using the compressor. After that, it is configured to be supplied again to the heating device and used for circulation. To the main body shell, superheated steam is supplied as a carrier gas, and the inside of the main body shell is kept at normal pressure. And evaporating moisture from an object, and taking in the heat medium the heat of a carrier gas containing water vapor evaporated from an object to be processed and discharged from an exhaust port formed in the main body shell. It is those composed of Te.

  Further, in the drying / concentration method according to claim 2, in addition to the above requirements, the carrier gas containing water vapor evaporated from the object to be processed, which is exhausted from the exhaust port of the processing chamber, is in a state of maintaining an overheated state. Is a feature.

  Furthermore, in addition to the above requirements, the drying / concentration method according to claim 3 is characterized in that the heating medium supplied to the heating device is saturated steam or superheated steam.

  Furthermore, the drying / concentration method according to claim 4 is characterized in that, in addition to the above requirements, the object to be processed is continuously processed.

  Furthermore, in the drying / concentration method according to claim 5, in addition to the above requirements, heat of a carrier gas containing water vapor evaporated from an object to be processed is discharged from an exhaust port formed in the main body shell. The heat medium discharged from the heating device is passed through the flow rate control valve, and then the heat of the carrier gas is taken into the heat medium using a heat exchanger. .

  Furthermore, in the drying / concentration method according to claim 6, in addition to the requirement according to claim 5, the pressure of the heat medium after passing through the flow control valve is measured on the upstream side or the downstream side of the heat exchanger. In addition, the temperature of the heat medium is measured on the downstream side of the heat exchanger, and the opening degree of the flow rate control valve is controlled based on the measured values, and the compression is performed based on the measured value of the pressure of the heat medium. It is characterized by controlling the suction amount of the heat medium in the machine.

  Furthermore, the drying / concentration method according to claim 7 is characterized in that, in addition to the above requirements, the heat of the heat medium discharged from the heating device is used as a heat source in the equipment constituting the heat pump processing device. is there.

  Further, the drying / concentration apparatus according to claim 8 is provided with a heating device in the main body shell, and the continuous conduction transmission configured to evaporate water by bringing the workpiece into contact with the heat transfer surface of the heating device. In the drying / concentration apparatus using the heat pump type processing apparatus provided with the heat dryer, the heat pump type processing apparatus is configured to increase the temperature of the heat medium discharged from the heating apparatus using a compressor. After that, it is configured so as to be supplied again to the heating device and circulated, and a mechanism for supplying superheated steam as a carrier gas to the main body shell is provided. In this state, moisture from the object to be processed is evaporated, and the heat of the carrier gas containing water vapor evaporated from the object to be processed discharged from the exhaust port formed in the main body shell is collected to the heat medium. Those comprising as a feature that it is configured to allow writing.

  Furthermore, in the drying / concentration apparatus according to claim 9, in addition to the requirement according to claim 8, the carrier gas containing water vapor evaporated from the object to be processed exhausted from the exhaust port of the processing chamber is in an overheated state. It is characterized by being configured to be in a maintained state.

  Furthermore, the drying / concentration device according to claim 10 includes a control mechanism capable of making the heating medium supplied to the heating device into saturated steam or superheated steam in addition to the requirements of claim 8 or 9. It is characterized by being made.

  Furthermore, the drying / concentration apparatus according to claim 11 is characterized in that, in addition to the requirements of claim 8, 9 or 10, the main body shell is configured on the assumption that it is used under normal pressure. It consists of.

  Furthermore, the drying / concentration device according to claim 12 is the exhaust of the processing chamber to the heat medium discharged from the heating device and passed through the flow control valve, in addition to the requirements of claim 8, 9, 10 or 11. It is characterized by comprising a heat exchanger that takes in the heat of the carrier gas containing water vapor evaporated from the object to be exhausted from the mouth.

  Furthermore, the drying / concentration device according to claim 13 includes a flow rate control valve through which the heat medium discharged from the heating device passes, in addition to the requirement according to claim 12, and the upstream side of the heat exchanger or A pressure sensor on the downstream side, a temperature sensor on the downstream side of the heat exchanger, and a control mechanism for controlling the opening of the flow control valve based on the measured values of temperature and pressure; And a control mechanism for controlling the suction amount of the heat medium of the compressor.

Furthermore, the drying / concentration apparatus according to claim 14 is the heat pump type processing apparatus, in addition to the requirements of claim 8, 9, 10, 11, 12, or 13, wherein the heat of the heat medium discharged from the heating apparatus is It is comprised so that it can provide as a heat source in the apparatus which comprises this.
The above problems can be solved by using the configuration of the invention described in each of the claims as a means.

According to the first aspect of the present invention, since superheated steam is used as the carrier gas, the water vapor evaporated from the object to be treated can be smoothly taken into the carrier gas, and the body shell is not evacuated without being evacuated. It becomes possible to promote evaporation of moisture from the processed material.
In addition, since it is not necessary to maintain a vacuum, a special function for maintaining the vacuum is necessary for a device for feeding an object to be processed into a dryer or a device for discharging an object to be dried discharged from a dryer. Therefore, a simple apparatus that can be easily maintained can be used for the front and rear devices centering on the dryer.
Furthermore, the heat of the carrier gas containing water vapor evaporated from the object to be processed discharged from the exhaust port is taken into the heat medium to recover waste heat, and further compressed to a high temperature / high pressure state by a compressor. Therefore, it can be used as a heat medium for heating. That is, since the heat energy of the carrier gas is used as a heat source for drying, it is possible to perform an energy saving operation.
Furthermore, since the heat medium is circulated and used in the heating device, the piping or equipment in the circulation path, especially components that adversely affect the compressor, etc. are not mixed into the heat medium and can be operated for a long time. Can continue.

  According to the invention of claim 2, since the carrier gas does not become saturated vapor in the main body shell, recondensation of water vapor evaporated from the object to be treated can be prevented and reliably taken into the carrier gas. . Also, since the carrier gas exhausted from the exhaust port is maintained in an overheated state in the path to the location where the heat is transferred to the heat medium, it does not condense and does not generate drainage, and the bag filter installed in this path Therefore, it is possible to avoid the dust collecting function from being impaired.

Furthermore, according to the invention described in claim 3, the difference between the temperature of the saturated steam or superheated steam supplied as the heat medium to the heating device and the temperature of the object to be processed is increased to increase the temperature of the indirect pressurized steam recompression type. A heat pump type processing apparatus can be reduced in size.
In addition, when superheated steam is supplied as a heat medium to the heating device, the sensible heat and latent heat of the superheated steam are conducted to the workpiece that contacts the outer surface (heat transfer surface) of the heating device. It is possible to promote the evaporation of moisture from the processed material.

Furthermore, according to the invention described in claim 4, it is possible to avoid a decrease in efficiency due to a decrease in the amount of evaporation accompanying the progress of drying, which has occurred in the case of the batch type.
In addition, when the properties of the object to be processed are uniform, the amount of superheated steam supplied into the main body shell can be made constant, and the amount of heat medium supplied to the heating device can be made constant, so that stable operation can be achieved. In addition, a dry product in a constant dry state can be obtained.

  Furthermore, according to the invention as set forth in claim 5, the heat medium discharged from the heating device is vaporized by the heat of the carrier gas including water vapor evaporated from the object to be processed, which is discharged from the exhaust port. Liquid compression in can be avoided. Further, it is not necessary to install a mist separator, and since there is no fear of a water hammer, there is no need to provide a steam trap, etc., so that restrictions on the route design can be greatly reduced and the route can be simplified.

Furthermore, according to the invention described in claim 6, it is possible to operate the pressure and temperature of the heat medium to be constant, and the heat exchange amount (heat recovery amount) between the carrier gas and the heat medium in the heat exchanger. Can be a predetermined amount. Further, the heat medium can be supplied in an appropriate amount according to the intake amount of the compressor, and the heat medium can be compressed to a high temperature and a high pressure without causing liquid compression in the compressor.
In addition, even when the state of the carrier gas containing water vapor evaporated from the processing object exhausted from the exhaust port of the processing chamber fluctuates, the change in the saturated state or the superheated state of the steam entering the compressor is made gradual. The operation | movement which suppressed the load fluctuation of the compressor can be performed.
Incidentally, in the control method in which the suction amount of the compressor is made constant in the conventional refrigeration system described in the background art and the pressure is the result, since the heat exchange in the heat exchanger is not constant, the drying / concentration method of the present invention The operation of such a heat pump system becomes unstable, and the energy recovery is reduced due to the lack of heat recovery.

  Furthermore, according to the seventh aspect of the present invention, the heat of the heat medium discharged from the heating device is used as a heat source for raising the temperature of the object to be processed in the hopper or the like constituting the indirect pressurized vapor recompression heat pump processing device. As a result, the energy required for drying and concentration can be reduced.

According to the invention described in claim 8, since superheated steam is used as the carrier gas, the water vapor evaporated from the object to be treated can be smoothly taken into the carrier gas, and the body shell is not evacuated without being evacuated. It becomes possible to promote evaporation of moisture from the processed material.
In addition, since it is not necessary to maintain a vacuum, a special function for maintaining the vacuum is necessary for a device for feeding an object to be processed into a dryer or a device for discharging an object to be dried discharged from a dryer. Therefore, a simple apparatus that can be easily maintained can be used for the front and rear devices centering on the dryer.
Furthermore, the heat of the carrier gas containing water vapor evaporated from the object to be processed discharged from the exhaust port is taken into the heat medium to recover waste heat, and further compressed to a high temperature / high pressure state by a compressor. Therefore, it can be used as a heat medium for heating. That is, since the heat energy of the carrier gas is used as a heat source for drying, it is possible to perform an energy saving operation.
Furthermore, since the heat medium is circulated and used in the heating device, there is a low possibility that components that have adverse effects such as corrosion of piping or equipment in the circulation path, especially the compressor, will be mixed into the heat medium, and good for a long time. Driving can be continued.

  Furthermore, according to the ninth aspect of the present invention, since the carrier gas does not become saturated vapor in the main body shell, it is possible to prevent recondensation of the water vapor evaporated from the object to be processed and reliably incorporate it into the carrier gas. it can. Also, since the carrier gas exhausted from the exhaust port is maintained in an overheated state in the path to the location where the heat is transferred to the heat medium, it does not condense and does not generate drainage, and the bag filter installed in this path Therefore, it is possible to avoid the dust collecting function from being impaired.

Furthermore, according to the invention described in claim 10, the difference between the temperature of the saturated steam or superheated steam supplied as a heat medium to the heating device and the temperature of the object to be processed is increased, and the indirectly pressurized steam recompression type is used. The drying / concentration apparatus to which the heat pump type processing apparatus is applied can be miniaturized.
In addition, when superheated steam is supplied as a heat medium to the heating device, the sensible heat and latent heat of the superheated steam are conducted to the workpiece that contacts the outer surface (heat transfer surface) of the heating device. It is possible to promote the evaporation of moisture from the processed material.

  Furthermore, according to the invention of claim 11, the drying / concentration apparatus to which the indirect pressurization type steam recompression type heat pump processing apparatus provided with the continuous conduction heat transfer dryer is applied is easy to maintain. It can be constructed as lightweight, simple and low cost.

  Furthermore, according to the twelfth aspect of the present invention, the heat medium discharged from the heating device is vaporized by the heat of the carrier gas discharged from the exhaust port and containing water vapor evaporated from the object to be processed. Liquid compression in can be avoided. In addition, there is no need to install a mist separator, and there is no danger of a water hammer, so there is no need to provide a steam trap, etc., and restrictions on route design can be greatly reduced and routes can be simplified.

  Furthermore, according to the thirteenth aspect of the present invention, even if the state of the carrier gas containing water vapor evaporated from the workpiece exhausted from the exhaust port of the processing chamber fluctuates, the saturated state of steam entering the compressor or overheating It is possible to perform an operation in which the change in state is gradual and the load fluctuation of the compressor is suppressed.

  Furthermore, according to the invention of claim 14, the heat of the heat medium discharged from the heating device is used as a heat source for raising the temperature of the object to be processed in a hopper or the like constituting an indirect pressurized vapor recompression type heat pump processing device. As a result, the energy required for drying and concentration can be reduced.

It is a block diagram which shows the drying / concentration apparatus of this invention. It is a side view which shows a dryer partially broken. It is the front view and back view which show a partially seeing dryer. It is sectional drawing which shows a compressor. It is a block diagram which shows the drying / concentration apparatus disclosed by patent document 1. FIG. It is a block diagram which shows the drying / concentration apparatus disclosed by patent document 2. FIG.

  The best modes of the drying / concentration method and the apparatus of the present invention are as shown in the following examples. However, these examples can be appropriately modified within the scope of the technical idea of the present invention. It is.

As shown in FIG. 1 as an example, the drying / concentration apparatus H of the present invention comprises a dryer 1, a charging device 2, a bag filter 3, a circulation path 4, and a compressor 5 as main components. An indirect pressurized vapor recompression type heat pump type processing apparatus is applied, and the components of the drying / concentration apparatus H will be described in detail below.
First, the dryer 1 will be described. In this case, as shown in FIGS. 2 and 3, a so-called conduction heat transfer type device is adopted, and a main body shell 10 as a processing chamber provided on the machine frame F is used. And a multi-tube heating tube 11 that functions as a condenser in this embodiment.
Then, the multi-tube heating tube 11 is rotated while flowing the superheated steam S5 as a heat medium therein, and the object to be processed is brought into contact with the outer surface (heat transfer surface) of the multi-tube heating tube 11 to be processed. Drying is performed by conducting the heat of superheated steam S5 to the object.
In the conduction heat transfer type dryer 1, the water vapor evaporated from the object to be processed in the shell body 10 is discharged to the outside by the carrier gas. It has become common knowledge in the art to use a product that has been heated or dehumidified.

Further, as shown in FIG. 3, the main body shell 10 is a hollow member having an elliptical cross section in this embodiment, and an inlet 101, an outlet 102, a carrier gas port 103, and an exhaust port 104 are formed. Here, the charging port 101 is formed near the end of the main body shell 10, and an exhaust port 104 is formed near the charging port 101. Further, the second inlet 101 is formed in a portion closer to the center than the exhaust port 104 in the main body shell 10. In this embodiment, the input port 101 is formed at two locations with the exhaust port 104 interposed therebetween. I did it. Of course, you may make it form the inlet 101 further in several places along the longitudinal direction of the multi-tube type heating tube 11 mentioned later. In addition, although the rotary valve 105 is provided in the said discharge port 102, you may make it provide a double damper type discharge device etc.
The main body shell 10 and the multi-tube heating tube 11 are installed in the machine frame F so as to be horizontal or inclined so that the inlet 101 side is somewhat higher than the outlet 102 side.

  Further, the main body shell 10 has a double jacket structure, and a passage through which a heating medium passes from the steam supply port 106 to the drain port 107 is formed so that the temperature inside the main body shell 10 can be raised. However, it is also possible to install a trace pipe instead of such a double jacket structure.

Further, the shell body 10 is configured on the assumption that it is used under normal pressure. Therefore, strict airtightness is not required, and a complicated charging / discharging mechanism and supply / exhaust mechanism are not required. is there. For this reason, the dryer 1 and the drying / concentration apparatus H can be constructed at a low cost.
Incidentally, in the drying / concentration apparatus H ′ disclosed in Patent Document 1 shown in FIG. 5, saturated steam (101 to 199 kPa-abs) at 100 to 120 ° C. is supplied to the multi-tube heating pipe 11 ′. In order to promote the evaporation of moisture from the object to be treated, it is necessary to lower the boiling point. For this reason, the main body shell 10 'is operated with a vacuum, and the main body shell 10' maintains airtightness. It is required to be able to do it.

The multi-tube heating tube 11 includes end plates 112 on both sides of a cylindrical tube bundle 116 and a shaft body 113 at the center of the end plate 112, and a bearing block provided in the machine frame F. The shaft body 113 is rotatably supported by 114. A motor M is provided on the machine frame F as a power source for rotating the multi-tube heating tube 11.
Rotary joints 115 a and 115 b are attached to both ends of the shaft body 113 and connected to the tube bundle 116. In addition, a seal mechanism is provided between the shaft body 113 and the main body shell 10 to block off from the outside air.
The tube bundle 116 has a plurality of angles 111 (12 in this embodiment) to which a plurality of lifters 117 and feed blades 118 having appropriate angles are attached. The object to be processed is scraped up and comes into contact with the tube bundle 116 and advances from the inlet 101 side to the outlet 102 side.

Next, the charging device 2 will be described. As an example, a monopump having a hopper 20 is applied, and the discharge port is connected to the charging port 101 in the dryer 1 through an appropriate pipe. .
In the drying / concentration apparatus H ′ shown in FIG. 5, the hopper 20 ′ has a structure capable of vacuum degassing to prevent air from being mixed into the main body shell 10 ′ of the dryer 1 ′. Thus, such a structure is not required in the drying / concentration apparatus H of the present invention.

  Next, the bag filter 3 will be described. In this embodiment, a shaking type bag filter is adopted as an example, and is connected to the exhaust port 104 in the main body shell 10. The filter element 30 can be vibrated by an appropriate swing mechanism to remove clogged dust and the like. In addition, various types such as a backwash type can be used as the bag filter 3.

Next, the circulation path 4 will be described. This pipe line is a closed circuit formed by connecting the rotary joint 115a and the rotary joint 115b in the multi-tube heating pipe 11, and a plurality of devices are provided in the middle. It is made up of. Specifically, a reserve tank 41, a flow control valve 42, a pressure sensor 43, a heat exchanger 45, a temperature sensor 46, a temperature sensor 47, and a pressure sensor 48 are provided from the side close to the rotary joint 115b. Further, the reserve tank 41 is provided with limit switches 41a and 41b at two upper and lower positions.
A compressor 5 is provided between the heat exchanger 45 and the rotary joint 115a. By adopting such a configuration, steam as a heat medium sealed in the circulation path 4 is compressed. The temperature is increased and the pressure is increased by the machine 5 and supplied to the multi-tube heating tube 11, and the temperature of the steam discharged from the multi-tube heating tube 11 is raised in the heat exchanger 45, and again by the compressor 5. It can be recycled by raising the temperature and raising the pressure.
A pipe line provided with a drain discharge valve 49 is connected to the reserve tank 41, and this pipe line is a device constituting the drying / concentration device H, a jacket of the main body shell 10, etc. By being connected to, the heat of the heat medium (drain D) discharged from the multitubular heating tube 11 can be used as a heat source for these devices.

  Next, the compressor 5 will be described. In this embodiment, a screw-type steam compressor is employed as an example, and this is a device having a high compression ratio while having low power consumption. Further, in this embodiment, as an example, one having the ability to compress superheated steam S4 with 90 kPa-abs, 100 ° C., superheat degree 3 degrees to 0.4 MPaG, 158 ° C., superheat degree 7 degrees is adopted. . For this reason, the difference of the temperature of superheated steam S5 and the temperature of a to-be-processed object can be taken large, and the dryer 1 can be reduced in size.

Here, the screw-type steam compressor as the compressor 5 will be described. As shown in FIG. 4, the compressor 5 includes a screw chamber 52a formed in the casing 52 and a pair of screws 53, 54 in an engaged state. The superheated steam S4 flowing into the screw chamber 52a from the air supply port 55 is compressed by the screws 53 and 54 and discharged from the exhaust port 56 in a heated state.
The screw chamber 52a is formed with a water injection port 57. By supplying cooling water from the water injection port 57 into the screw chamber 52a, the degree of superheat of the superheated steam S4 compressed in the screw chamber 52a is increased. It becomes possible to control.
As the compressor 5, a multistage root type compressor, a multistage turbo blower, or the like can be adopted as long as it can realize the compression capability.
In the drying / concentration apparatus H ′ shown in FIG. 5, a mist separator for removing mist in the gas is provided between the compressor 51 ′ and the compressor 52 ′. In the concentrator H, superheated steam S4 is supplied to the compressor 5 and discharged as superheated steam S5 with an appropriately controlled superheat degree, as will be described later, so that such a mist separator is not necessary. Is.

  Further, the drying / concentrating device H is provided with a steam generating device 8, and an appropriate device such as a U shape, a straight tube shape, a helical coil shape, or the like is applied. As will be described later, the steam generator 8 is connected so that the steam S0 is supplied to the super heater 6, the rotary joint 115a (circulation path 4), and the steam supply port 106.

Here, the steam S0 is the superheated steam S1 and then supplied to the carrier gas port 103 in the dryer 1, and the super heater 6 for this purpose is provided in front of the carrier gas port 103. In this embodiment, an electric heater is applied as an example of the super heater 6, and the steam S 0, which is saturated at about 151 ° C. at 0.4 MPaG by the pressure reducing valve 81, is changed to 160 ° C. (superheat degree). 60 degree) of superheated steam S1 is used.
A temperature sensor 70 is provided on the superheater 6 discharge side of the superheated steam S1, and heating by the superheater 6 is performed so that the measured value of the temperature sensor 70 becomes a desired value (160 ° C. in the above example). Shall be controlled.

Further, as described above, auxiliary steam can be supplied from the steam generator 8 to the rotary joint 115a. In the vicinity of the rotary joint 115a in the circulation path 4, a pressure reducing valve 83, a flow rate adjusting valve 84, and The steam piping path provided with is connected.
As will be described in detail later, when the steam located in the circulation path 4 is discharged to the outside as drain D through the reserve tank 41 and the drain discharge valve 49, the circulation path 4 is replenished through the steam piping path to replenish it. Auxiliary steam is supplied. Even when the multi-tube heating pipe 11 has not sufficiently increased in temperature, such as when the dryer 1 is started up, auxiliary steam is supplied to the rotary joint 115a through the steam pipe path in order to heat the multi-tube heating pipe 11. It is what is done.

The superheated steam S1 is a normal pressure, but the normal pressure here generally means an atmospheric pressure (1 atm) and varies depending on weather conditions and geographical conditions. .
Further, the purpose of setting the superheated steam S1 to normal pressure is to suck outside air into the drying system (the space in the main body shell 10 where the object to be processed exists and the space communicating therewith) or from the drying system to the outside air side. This is to prevent leakage of the superheated steam S2 to the water.
If the pressure of the superheated steam S1 is in the range of −1 to +1 kPa with respect to the atmospheric pressure, a general and simple sealing material or seal mechanism sucks in the outside air or the superheated steam S2 to the outside air side. Leakage can be prevented. In the present specification, “normal pressure” includes a range of −1 to +1 kPa with respect to the atmospheric pressure.
Of course, if a sealing material or a sealing mechanism that can further improve the airtightness is employed, the pressure of the superheated steam S1 can be allowed in a wider range.

The drying / concentration apparatus H of the present invention is configured as described above as an example, and the drying / concentration method of the present invention will be described below together with the operation method of this apparatus.
(1) Preparation of dryer First of all, prior to the introduction of the workpiece, the multi-tube heating tube 11 and the main body shell 10 in the dryer 1 are heated, and the motor M is activated to start the multi-tube type. Auxiliary steam is supplied to the rotary joint 115a, the carrier gas port 103, and the steam supply port 106 while the heating tube 11 is rotated.
Further, when preparing the dryer 1, a drain discharge path (provided in the circulation path 4) for drainage D generated in the multi-tube heating pipe 11 and non-condensable gas such as air that has entered due to leakage (see FIG. It is discharged from the circulation path 4 through a condensable gas discharge path (not shown).
Here, a temperature sensor 71 is provided in the end plate 112 on the discharge port 102 side (specifically, only the tip portion for sensing the temperature sensor 71 is inserted in the end plate 112), and the above-mentioned multi-tube type. The temperature of the heating tube 11 is measured. This temperature sensor 71 is disposed in the end plate 112 on the discharge port 102 side through a rotary joint 151b and a shaft body 113 together with a drain discharge pipe (not shown) described later.
Then, after the above-described drain D and non-condensable gas are discharged and the temperature sensor 71 reaches a predetermined temperature, the pump P1 is started, so that the inside of the drying system of the drying / concentration apparatus H (the object to be processed is While discharging the non-condensable gas in the existing space in the main body shell 10 and the space communicating therewith, the atmosphere in the drying system is replaced with the superheated steam S1. When drain D is generated between the heat exchanger 45 and the pump P1, the drain discharge pump P2 is activated and the drain D is discharged.

(2) Deaeration process Next, the to-be-processed object (organic sludge as an example) supplied to the hopper 20 in the injection apparatus 2 is deaerated. Thereafter, it is preferable to further fill the superheated steam S1 in the hopper 20.

(3) Circulation of heat medium Next, the compressor 5 is started, the steam as the heat medium located in the circulation path 4 is heated and pressurized, and supplied to the multi-tube heating pipe 11 as superheated steam S5. is there.
The superheated steam S5 having a lowered temperature discharged from the multi-tube heating pipe 11 is stored in the reserve tank 41 in a drain state, and then becomes wet steam S3 via the flow rate control valve 42, and this wet steam S3. Is heated in the heat exchanger 45 to become superheated steam S4, and this superheated steam S4 is heated and boosted by the compressor 5 and supplied again to the multi-tube heating pipe 11 as superheated steam S5.

In addition, the compressor 5 is heated in the heat exchanger 45 so that the superheated steam S4 that is reliably overheated is compressed into the superheated steam S5, so that mist or drain is not generated. As a result, damage due to liquid compression of the compressor 5 is surely avoided.
Specifically, as described below, the drain or steam in the reserve tank 41 passes through the flow rate control valve 42 to become wet steam S3, and passes through the heat exchanger 45 to be the exhaust port 104 of the dryer 1. The heat of the carrier gas exhausted from is taken into superheated steam S4.
When the object to be processed is introduced into the dryer 1, the carrier gas exhausted from the exhaust port 104 contains moisture from the object to be processed, and the carrier gas containing the moisture passes through the heat exchanger 45. By passing, heat is applied to the wet steam S3.
Further, the pressure of the wet steam S3 is measured by the pressure sensor 43, the temperature of the superheated steam S4 is measured by the temperature sensor 46, and the measured values of these pressure and temperature are calculated by, for example, a programmable logic controller (PLC). The degree of superheat is required. And in order to make superheat degree of superheated steam S4 into desired superheat degree, the opening degree of the flow control valve 42 is controlled by the control circuit which is not illustrated.

  Next, the superheated steam S4 (for example, temperature 100 ° C., 90 kPa-abs) that has reached the compressor 5 through the circulation path 4 is compressed and heated by the action of the screw (for example, temperature 158 ° C., pressure 0.4 MPaG). ) Superheated steam S5 (superheat degree 7 degrees) is supplied to the rotary joint 115a. The superheated steam S5 passes through the shaft 113, enters the end plate 112, and passes through the tube bundle 116. In this process, as will be described later, the superheated steam S5 contacts the outer surface of the multi-tube heating tube 11. Since the sensible heat and latent heat of the superheated steam S5 are conducted to the object to be processed, evaporation of moisture from the object to be processed can be promoted.

The rotational speed of the screws 53 and 54 of the compressor 5 is controlled based on the pressure value of the pressure sensor 43. That is, the pressure of the wet steam S3 after passing through the flow control valve 42 is measured, and the rotation speed of the screws 53 and 54 of the compressor 5 is controlled so that the pressure becomes, for example, 90 kPa-abs, and the compression of the superheated steam S4 is performed. The amount of suction into the machine 5 is controlled.
Further, the temperature and pressure of the superheated steam S5 discharged from the compressor 5 are measured by a temperature sensor 47 and a pressure sensor 48, respectively. And the measured value of this temperature sensor 47 and the pressure sensor 48 is calculated by a programmable logic controller (PLC), for example, and the superheat degree of superheated steam S5 is calculated | required. In order to set the superheat degree of the superheated steam S5 to a desired superheat degree, the opening degree of the water injection control valve 58 is controlled, and the superheated steam S4 is compressed and heated in the screws 53 and 54 of the compressor 5. Water is poured into the (screw chamber 52a), thereby controlling the degree of superheat of the superheated steam S5.
In addition, for example, when the temperature drop of the superheated steam S5 due to the heat radiation of the circulation path 4 is expected, for example, when the superheated steam S5 at 140 ° C. is supplied to the multi-tube heating pipe 11, the temperature drop is 5 degrees. The superheat degree may be adjusted by the water injection control valve 58 so that the temperature of the superheated steam S5 immediately after being discharged from the compressor 51 becomes 145 ° C.
In addition, although demonstrated here performing water injection to the screw chamber 52a of the compressor 5, you may inject water with respect to the superheated steam S5 discharged from the screw chamber 52a. In that case, it is preferable to pour water in a sprayed state using a spray nozzle or the like.

(4) Drying of processing object and supply of carrier gas Next, the processing object is charged into the main body shell 10 through the charging port 101 from the charging device 2, and this is the side of the charging port 101 by the action of the feed blade 118. Then, it moves to the discharge port 102 side, and is further picked up by the lifter 117 and comes into contact with the tube bundle 116 and the like. At this time, the moisture is evaporated by receiving heat.
At this time, since the inlets 101 are formed at a plurality of locations along the longitudinal direction of the multi-tube heating tube 11, the heat conduction surface of the multi-tube heating tube 11 can be used effectively, and the drying efficiency is increased. It is done.
In addition, by starting the pump P1, superheated steam S1 (normal pressure, about 160 ° C.) generated by the super heater 6 is supplied into the main body shell 10 through the carrier gas port 103 as a carrier gas. The water vapor evaporated from the processed material is quickly taken into the carrier gas. In addition, since a to-be-processed object is heated also by superheated steam S1, moisture evaporation is accelerated | stimulated.
And the organic sludge which reached the discharge port 102 is discharged | emitted in the state used as the dried product, and is transferred to the following process.

(5) Exhaust of carrier gas and maintenance of superheated state On the other hand, the carrier gas (superheated steam S1) that takes in water vapor evaporated from the object to be treated is exhausted from the exhaust port 104 to the outside of the main body shell 10, This exhaust is maintained in an overheated state (superheated steam S2). Specifically, the temperature of the superheated steam S2 is measured by a temperature sensor 73 provided in a pipe line connecting the bag filter 3 and the heat exchanger 45, and the flow rate of the steam S0 is determined based on this value. To maintain the superheated state of the superheated steam S2.
On the other hand, the pressure sensor 72 measures the pressure in the space where the material to be treated in the main body shell 10 exists, and the pressure is in the range of −1 to +1 kPa (ie, −1 to +1 kPaG) with respect to the atmospheric pressure. Exhaust is performed by controlling the rotational speed of the pump P1, for example.
The body shell 10, the exhaust port 104, the bag filter 3 and the pipeline are provided with, for example, an electric heater for tracing, and the temperature sensor 73 is used to control the carrier gas so as to maintain a desired overheating state. You may make it perform.

  Further, a small amount of fine powder contained in the superheated steam S <b> 2 discharged from the exhaust port 104 is separated in the bag filter 3. In addition, when the clogging of the bag filter 3 proceeds, the shaking mechanism is appropriately operated to remove the fine powder. In this case, the fine powder can be removed without using the backwash gas. The increase in pressure loss of the bag filter 3 can be avoided. If it is difficult to remove the fine powder by the shaking mechanism, it is necessary to backwash the filter element 30. In this case, it is preferable to use superheated steam as the backwashing gas, for example, superheated steam. Backwashing is performed by supplying S1 to an appropriate backwashing mechanism (not shown) of the bag filter 3.

(6) Utilization of drain In the reserve tank 41, the amount of liquid in the tank is detected by the limit switches 41a and 41b, and when the liquid level is detected by the limit switch 41a, the drain discharge valve 49 is opened, and the drain D is supplied to the charging device 2 and the jacket of the main body shell 10 which are devices constituting the drying / concentration device H, and is used as a heat source for these devices. Eventually, when the liquid level is detected by the limit switch 41b, the drain discharge valve 49 is closed.

Here, an example of the temperature and pressure of steam S0, superheated steam S1, S2, S4, S5 and wet steam S3 when organic sludge is treated by the drying / evaporating apparatus H of the present invention is shown below.

S0: 151 ° C 0.4 MPaG
S1: 160 ° C. −1 to 1 kPaG
S2: 112 ° C. −1 to 1 kPaG
S3: 97 ° C. 90 kPa-abs
S4: 100 ° C. 90 kPa-abs
S5: 158 ° C 0.4 MPaG

Moreover, according to this invention, since the said to-be-processed object can be processed continuously, the efficiency fall resulting from the reduction | decrease in the evaporation amount accompanying the progress of drying which had arisen in the case of a batch type can be avoided. When the properties of the object to be processed are uniform, the supply amount of the superheated steam S1 into the main body shell 10 is made constant, and the supply amount of the superheated steam S5 to the multitubular heating tube 11 is made constant. Therefore, stable operation can be performed.
Further, the steam discharged from the compressor 5 is saturated steam, and, for example, an electric heater for tracing is applied from the compressor 5 to the rotary joint 115a, and the electric heater is controlled by the temperature sensor 47 and the pressure sensor 48. The saturated steam discharged from the compressor 5 can be changed to a desired degree of superheat.

In the above description, the case where the object to be processed is started from the state in which the object to be processed does not exist in the main body shell 10 has been described. It is also possible to remove the lid plate, put it into the main body shell 10, fill it up as appropriate, and then start feeding the workpiece through the loading port 101 after preparing the dryer 1 described above.
Furthermore, at the end of the drying operation, the drying operation is terminated in a state where an appropriate amount is left without discharging all the objects to be processed in the main body shell 10, and at the start of the next operation, at the end of the previous drying operation You may make it start the input of a to-be-processed object through the preparation of the above-mentioned dryer 1 from the state in which the to-be-processed object left in the main body shell 10 exists.

In the above-described embodiment, the multi-tube heating tube 11 is used as the superheater. However, a hollow disk-shaped heat transfer member or a hollow paddle-shaped heat transfer member is used instead of the tube of the multi-tube heating tube 11. It is also possible to apply superheated steam S5 to the inside.
Further, as a heating device, for example, a jacket is provided on the outer surface of the main body shell 10 and superheated steam S5 is supplied to the jacket, whereby the object side of the main body shell 10 is used as a heat transfer surface, and the inside of the main body shell 10 is covered. The thing of the structure only provided with the stirring body which only stirs a processed material is also employable.

H Dryer / Concentrator 1 Dryer 10 Main Body Shell 101 Input Port 102 Discharge Port 103 Carrier Gas Port 104 Exhaust Port 105 Rotary Valve 106 Steam Supply Port 107 Drain Port 108 Side Opening 11 Multi-tube Heating Tube (Heating Tube)
DESCRIPTION OF SYMBOLS 111 Angle 112 End plate 113 Shaft body 114 Bearing block 115a Rotary joint 115b Rotary joint 116 Tube bundle 117 Lifter 118 Feeding blade 2 Input device 20 Hopper 3 Bag filter 30 Filter element 4 Circulation path 41 Reserve tank 41a Limit switch 41b Limit switch 42 Flow control Valve 43 Pressure sensor 45 Heat exchanger 46 Temperature sensor 47 Temperature sensor 48 Pressure sensor 49 Drain discharge valve 5 Compressor 52 Casing 52a Screw chamber 53 Screw 54 Screw 55 Air supply port 56 Exhaust port 57 Water injection port 58 Water supply control valve 6 Super heater DESCRIPTION OF SYMBOLS 70 Temperature sensor 71 Temperature sensor 72 Pressure sensor 73 Temperature sensor 8 Steam generator 81 Pressure reducing valve 82 Flow control valve 83 Pressure reducing valve 84 Flow control valve D Drain F Machine frame M Motor P1 pump P2 Drain discharge pump S0 Steam S1 Superheated steam S2 Superheated steam S3 Wet steam S4 Superheated steam S5 Superheated steam

Claims (14)

  A heat pump type processing device provided with a continuous conduction heat transfer drier configured to have a heating device in the main body shell, and to evaporate water by bringing a workpiece into contact with the heat transfer surface of the heating device. In the drying / concentration method used, the heat pump type processing apparatus heats the heat medium discharged from the heating apparatus at a reduced temperature using a compressor, and then supplies the heat medium again to the heating apparatus for circulation. In the state where superheated steam is supplied as a carrier gas to the main body shell and the inside of the main body shell is at normal pressure, moisture from the object to be processed is evaporated, and the main body shell A drying / concentration method characterized in that heat of a carrier gas containing water vapor evaporated from an object to be processed discharged from an exhaust port formed in the shell is taken into the heat medium.   2. The drying / concentration method according to claim 1, wherein the carrier gas containing water vapor evaporated from the object to be processed, which is exhausted from the exhaust port of the processing chamber, is maintained in an overheated state.   The drying / concentration method according to claim 1 or 2, wherein the heat medium supplied to the heating device is saturated steam or superheated steam.   4. The drying / concentration method according to claim 1, wherein the object to be processed is continuously processed.   When the heat of the carrier gas including water vapor evaporated from the object to be processed, which is discharged from the exhaust port formed in the main body shell, is taken into the heat medium, the heat medium discharged from the heating device is controlled in flow rate. 5. The drying / concentration method according to claim 1, wherein after passing through the valve, the heat of the carrier gas is taken into the heat medium using a heat exchanger.   Based on these measured values, the pressure of the heat medium after passing through the flow control valve is measured upstream or downstream of the heat exchanger, and the temperature of the heat medium is measured downstream of the heat exchanger. 6. The drying / concentration method according to claim 5, wherein the opening of the flow control valve is controlled and the suction amount of the heat medium in the compressor is controlled based on the measured value of the pressure of the heat medium. Method.   The drying / concentration method according to claim 1, 2, 3, 4, 5 or 6, wherein the heat of the heat medium discharged from the heating device is used as a heat source in an apparatus constituting a heat pump type processing apparatus.   A heat pump type processing device provided with a continuous conduction heat transfer drier configured to have a heating device in the main body shell, and to evaporate water by bringing a workpiece into contact with the heat transfer surface of the heating device. In the drying / concentration apparatus used, the heat pump type processing apparatus heats the heat medium discharged from the heating apparatus at a reduced temperature using a compressor, and then supplies the heat medium again to the heating apparatus for circulation. A mechanism for supplying superheated steam as a carrier gas to the main body shell, and evaporating moisture from the object to be processed in a state where the main body shell is at normal pressure. And the heat of the carrier gas containing water vapor evaporated from the object to be processed and discharged from the exhaust port formed in the main body shell can be taken into the heat medium. Drying and concentration and wherein the.   9. The drying / cleaning method according to claim 8, wherein the carrier gas containing water vapor evaporated from the object to be processed, which is exhausted from the exhaust port of the processing chamber, is in a state of maintaining an overheated state. Concentrator.   The drying / concentrating device according to claim 8 or 9, further comprising a control mechanism capable of setting the heating medium supplied to the heating device to saturated steam or superheated steam.   The drying / concentration apparatus according to claim 8, 9 or 10, wherein the main body shell is configured on the assumption that the main body shell is used under normal pressure.   A heat exchanger that takes in the heat of the carrier gas containing water vapor evaporated from the object to be processed discharged from the exhaust port of the processing chamber into the heat medium discharged from the heating device and passed through the flow rate control valve; The drying / concentrating device according to claim 8, 9, 10 or 11.   A flow control valve through which the heat medium discharged from the heating device passes, a pressure sensor upstream or downstream of the heat exchanger, and a temperature sensor downstream of the heat exchanger; And a control mechanism for controlling the opening degree of the flow rate control valve based on the measured value of the pressure, and a control mechanism for controlling the suction amount of the heat medium of the compressor based on the measured value of the pressure. The drying / concentration apparatus according to claim 12.   It is comprised so that the heat | fever of the heat medium discharged | emitted from the said heating apparatus can be provided as a heat source in the apparatus which comprises a heat pump type | mold processing apparatus, It is characterized by the above-mentioned. Or the drying / concentration apparatus of 13.

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