JP5632410B2 - Heat treatment equipment and method - Google Patents

Description

  The present invention relates to a heat treatment facility and method for economically recovering the amount of heat of a dry exhaust gas generated in an indirect heat dryer and using it as a heat source for the dryer, after drying an object to be treated containing moisture and organic matter. It can be applied to facilities that incinerate by heat treatment or collect flammable gases and carbides.

  In recent years, various processes have been developed for pyrolyzing biomass, coal, oil shale, oil sand and the like to produce combustible gas and carbide. And if these substances are pre-dried before being supplied to the thermal decomposition step, the heat treatment can be carried out more economically.

  Here, as a dryer for pre-drying, a heating medium such as steam is used as a heating source, an indirect heating type dryer that dries the object to be processed without directly contacting the object to be processed with the heat medium, and burns fuel. In addition, there are known a direct heating type dryer in which the generated hot air is brought into direct contact with an object to be processed, and a dryer in which indirect heating and direct heating are used in combination.

JP 2005-279331 A

  Conventionally, the dry exhaust gas used in these dryers is discharged after removing dust and harmful substances, and the amount of heat of the dry exhaust gas (mainly latent heat of steam) has not been effectively recovered. In addition, although the method (patent document 1) which heat-recovers from dry exhaust gas and obtains warm water and uses this warm water as a heating source to dry by indirect heating under reduced pressure is known, in this method, the temperature of the heating source is low. Economic drying was difficult.

  Therefore, the present inventor, in Japanese Patent Application No. 2010-238228, economically collects the heat quantity of the dry exhaust gas generated in the dryer and the heat quantity of the exhaust gas generated when the dried material is heat-treated, The mode which can be used effectively as is proposed, and its effectiveness has been confirmed.

  However, on the other hand, the amount of steam generated in a boiler that uses exhaust gas generated when heat-treating the dried product as a heating source may not be sufficient. In particular, when the moisture content of the material to be processed is high, the amount of pressurized steam used in the dryer is large, and the amount of steam generated in the boiler is relatively small, so that the steam pressure in the dryer is sufficiently stabilized. It may lead to a situation that cannot be done. If the steam pressure in the dryer is not stable, the moisture content of the dried product becomes large, which becomes a factor that hinders stable operation of the heat treatment equipment in the subsequent process.

  The present invention has been made in view of the above circumstances, and its main problem is to provide a heat treatment facility and method for economically recovering the amount of heat of the dry exhaust gas generated in the dryer and using it as a heat source for the dryer. There is to do.

  Another problem is to enable stable system operation without being affected by supply conditions (processing amount, moisture, etc.) of the workpiece.

1st invention dries the to-be-processed object containing a water | moisture content and an organic substance, The heat processing containing the indirect heating type dryer which uses a steam as a heating source, and the heat processing equipment which heats the to-be-processed object dried with the dryer In equipment,
First steam generating means for recovering the retained heat of the dry exhaust gas generated by the indirect heating dryer and generating first steam;
Second steam generating means for generating second steam using at least one of combustible gas or combustion exhaust gas generated in the heat treatment facility as a heat source;
Vapor compression means for mechanically compressing the first vapor;
Steam storing means for temporarily storing the compressed steam by the steam compressing means and the second steam by the second steam generating means;
Steam supply means for supplying the stored steam from the steam storage means as a heating source for drying the object to be processed by an indirect heating dryer;
A pressure measuring means in the steam storage means and a pressure control means for controlling the first steam generating means based on a pressure measurement value by the pressure measuring means;
It is the heat processing equipment characterized by this.

  The indirect heating dryer in the present invention includes an indirect heating dryer using a heat medium such as steam as a heating source, and a direct heating drying using hot air generated by burning fossil fuel as a heating source. There are dryers and dryers that use both indirect heating and direct heating, but excluding direct heating dryers that use hot air generated by burning fossil fuel as a heating source.

  Examples of the indirect heating type dryer in the present invention include a disc type dryer (inclined disc dryer), a steam tube dryer, and a fluidized dryer with an indirect heating tube.

  The heat treatment in the present invention may be a treatment for heating a dried object to be processed, and includes combustion such as thermal decomposition such as carbonization and gasification, and incineration.

  The general configuration of the present invention is shown in FIG. 4 (not limited to the embodiment shown in FIG. 4), so that it can be easily understood.

(Function and effect)
The higher the steam temperature (pressure), the more economical the dryer can be made. On the other hand, running costs are required to obtain high temperature (high pressure) steam. There is therefore an optimum steam temperature (pressure). According to the present invention, as steam supplied as a heating source for drying an object to be processed by an indirect heating dryer, steam having a constant pressure can be always supplied to the indirect heating dryer, and the supply condition of the object to be processed is constant. Below, the moisture of the dried product is stabilized and the system is stabilized.

In addition to the first invention, the second invention is the dried product moisture measurement result measured by the dried product moisture measuring means for measuring the moisture of the dried product dried by the indirect heating dryer, and the temperature of the dried product. Based on at least one of the dry matter temperature measurement results measured by the dry matter temperature measurement means to measure, comprising a steam storage pressure setting means for determining a set value of the internal pressure of the steam storage means,
The pressure control means is a heat treatment facility that controls the first steam generation means so that the measured pressure value becomes the set value.

  The moisture measuring means may be any method as long as it can measure the moisture of the object to be processed, and a microwave moisture meter, an infrared moisture meter, a heat drying moisture meter, or the like can be used.

(Function and effect)
In addition to the effect of the first invention, based on the measured moisture value and / or measured temperature value of the dried product, a set value of the steam pressure supplied to the indirect heating dryer so that the moisture of the dried product becomes a predetermined value By changing, the moisture of the dried product is stabilized regardless of the supply conditions (supply amount, moisture, etc.) of the object to be processed, so that the system can be stabilized.

  According to a third aspect of the present invention, in addition to the first or second aspect of the invention, the heat condensate in the indirect heating type dryer is returned to at least one of the first steam generation means and the second steam generation means as a steam source. Equipment.

  Since it returns as a steam source, the amount of steam can be increased.

4th invention dries the to-be-processed object containing a water | moisture content and an organic substance, The heat processing containing the indirect heating type dryer which uses a steam as a heat source, and the heat processing equipment which heats the to-be-processed object dried with the dryer In the method
A first steam generation step of recovering the retained heat of the dry exhaust gas generated in the indirect heating dryer to generate the first steam;
A second steam generating step for generating a second steam using at least one of a combustible gas or combustion exhaust gas generated in the heat treatment facility as a heat source;
A vapor compression step of mechanically compressing the first vapor;
A steam storage step for temporarily storing the compressed steam by the vapor compression step and the second steam by the second steam generation step;
A steam supply process for supplying the stored steam from the steam storage process as a heating source for drying the object to be processed by an indirect heating dryer;
A pressure control step of controlling the first steam generation step so that the pressure in the storage means of the steam storage step becomes a predetermined set value,
It is the heat processing method characterized by the above-mentioned.

  There are substantially the same effects as the first invention.

  In the fifth aspect of the invention, in addition to the configuration of the fourth aspect of the invention, the set value of the pressure in the vapor storage means is adjusted based on at least one of the moisture or temperature of the dried product dried by the indirect heating dryer. The heat treatment method characterized by the above.

  The effect substantially the same as 2nd invention is show | played.

  As described above, according to the present invention, it is possible to provide heat treatment equipment that economically recovers the amount of heat of dry exhaust gas generated in a dryer and uses it as a heat source of the dryer.

  In addition, according to the present invention, after drying an object to be processed containing moisture and organic matter, when the object to be processed is heated with a heating facility, an effective drying heat source is obtained by economically recovering heat from the dried exhaust gas. I was able to do that.

  For example, when the processing amount is 100 t / day of sewage sludge, the treatment unit price of sewage sludge is reduced by 1,700 yen / t according to the present invention, compared with the conventional carbonization equipment with hot air drying equipment by combustion of fuel. The amount of CO2 emission is reduced to 2,600 t / year.

  Furthermore, according to the present invention, steam having a constant pressure can be always supplied to the indirect heating dryer as steam supplied as a heating source for drying the object to be processed by the indirect heating dryer, and supply of the object to be processed Under constant conditions, the moisture of the dried product is stabilized and the system is stabilized. Further, based on the measured moisture value and / or the measured temperature value of the dried product, the set value of the steam pressure supplied to the indirect heating dryer is changed so that the moisture content of the dried product becomes a predetermined value. Regardless of the supply conditions (supply amount, moisture, etc.), the moisture of the dried product is stabilized, so that the system can be stabilized.

1 is a partially broken perspective view of a steam tube dryer according to an embodiment of an indirect heating dryer of the present invention. It is the schematic which shows the drying and carbonization equipment of the sewage sludge concerning 1st this Embodiment. It is the schematic which shows the drying and carbonization equipment of the sewage sludge concerning 2nd this Embodiment. It is an outline explanatory view of the present invention. It is a graph which shows an example of the relationship between the temperature of a dried material, and the water | moisture content of a dried material.

  An embodiment of a heat treatment facility according to the present invention will be described below with reference to the drawings. First, prior to the description of the present embodiment, an example of a steam tube dryer (STD) that is an indirect heating dryer applied to the embodiment of the present invention will be described with reference to FIG. explain.

  This steam tube dryer 3 shown in FIG. 1 has a plurality of heating pipes 31 arranged between both end plates in parallel with the axis in a rotary cylinder 30 that is rotatable around the axis. Heated steam as a heat medium is supplied to the heating pipes 31 through the attached heat medium inlet pipes 51 and circulates through the respective heating pipes 31, and then drains the pressurized steam K through the heat medium outlet pipes 52. Will be discharged.

  The steam tube dryer 3 is provided with a charging device (not shown) having a screw or the like for charging the workpiece into the rotary cylinder 30. For example, an organic substance containing moisture, which is an object to be processed, which is introduced from one end side into the rotary cylinder 30 through the insertion port 53 of this charging device, is brought into contact with the heating tube 31 heated by the evidence vapor K and dried. To become. At the same time, since the rotating cylinder 30 is installed with a downward slope, it is moved smoothly in the direction of the discharge port 54 so that the workpiece is continuously discharged from the other end side of the rotating cylinder 30. Yes.

  As shown in FIG. 1, the rotating cylinder 30 is installed on a base 36, and the tire 34 is mounted by two sets of support rollers 35 that are spaced apart from each other in parallel with the axis of the rotating cylinder 30. It is supported through. The width between the two sets of support rollers 35 and the inclination angle in the longitudinal direction thereof are selected in accordance with the downward gradient and the diameter of the rotating cylinder 30.

  On the other hand, in order to rotate the rotating cylinder 30, a driven gear 40 is provided around the rotating cylinder 30, and the drive gear 43 meshes with the driven gear 40, and the rotational force of the prime mover 41 is transmitted via the speed reducer 42. Thus, it rotates around the axis of the rotating cylinder 30. Further, a carrier gas is introduced into the inside of the rotary cylinder 30 from a carrier gas inlet 61, and these carrier gases are accompanied by vapors in which water contained in the organic substance as the object to be processed is evaporated, from the carrier gas outlet 62. Discharged.

  In addition, the whole structure of the said steam tube dryer 3 is an example, and this invention is not limited by the said structure.

  FIG. 2 is a schematic view showing a sewage sludge drying / carbonizing facility according to the first embodiment of the present invention.

  On the charging side of the steam tube dryer 30, a paddle type or multi-shaft type mixer 2 is disposed. In the mixer 2, the sewage sludge from the sludge supply pump 1 and the dried product returned through the return conveyor 8 are mixed to adjust the water content, and the mixture is granulated to a certain size in the mixing process. . The granulated mixture is dried as a dried product S having a water content of about 10% in the steam tube dryer 30.

  The dry exhaust gas G discharged from the steam tube dryer 30 is sent to the dry exhaust gas wet scrubber 9, and the heat recovered by the dry exhaust gas wet scrubber 9 is heat-exchanged in the heat pump heater 10 to form a heat pump. 25 heating sources.

  In this example, the dry exhaust gas wet scrubber 9, the heat pump heater 10, and the heat pump 25 constitute the first steam generating means. The first steam is generated in the first steam generating means, and the first steam is sent to the compressor 13 as the first pressure increasing means and compressed. The compressed steam is sent to a steam header 29 as steam storing means.

  The heat pump 25 includes an evaporator 26, a heat pump compressor 27, and a condenser 28. The heat pump compressor is provided with a control device that performs variable voltage variable frequency control (VVVF control), and controls the amount of steam generated by the heat pump 25 according to the pressure in the steam header 29 described later.

  From the steam header 29, steam is sent to the steam tube dryer 30 via the path 22 and used as heating steam for the steam tube dryer 30. Some are used or discarded as traces. The drain heated by the steam tube dryer 30 is sent to at least one of the heat pump 25 and the boiler 19 via the path 23.

  In addition to the example using this heat pump 25, the dry exhaust gas wet scrubber 9, the evaporator heater, and the evaporator can constitute the first steam generating means.

  On the other hand, the dried product S in the steam tube dryer 30 is discharged on the dried product transfer conveyor 4 on the lower side of the discharge side, and then sieved by the sieve 5, and the dried product S1 of small particles is returned to the return hopper 7a. To be collected. The large particle dried product S2 is sent to the dried product hopper 9, and a part thereof is pulverized by the crusher 6 and then collected in the return hopper 7a.

If the sieve 5 is a device in which a plurality of sieve members having different opening diameters are arranged in a multi-stage shape, only a predetermined particle size is sent to the dry product hopper 9, and a dry product having a smaller particle size is sent to the return hopper 7a. On the other hand, a dried product larger than the predetermined particle size can be sent to the crusher 6.

  A small particle dried product S1 is cut out from the return hopper 7a, sent to the mixer 2 by the return conveyor 8, mixed with sewage sludge, and then returned to the steam tube dryer 30.

  On the other hand, from the lower part of the dry product hopper 9, the large particle dry product S2 can be put on the dry product transfer conveyor 15 and put into the carbonization furnace 16 which is a heating facility. Carbonized.

  The carbonization furnace 16 is supplied with hot air generated by burning fuel in the hot air generator 17 for carbonization furnace. The combustible gas N is discharged from the carbonization furnace 16 and sent to the afterburner 18 as a fuel element, and the combustible gas N is combusted together with air and fuel. The combustion exhaust gas discharged from the afterburner 18 is supplied to the boiler 19 and used as a heating source.

  Steam generated in the boiler 19 is sent to the steam header 29 via the pipe line 32. The ejector 40 is provided in the pipe line 32. The ejector 40 is used to increase the amount of steam by sucking the steam discharged from the heat pump 25 using the steam generated from the boiler 19 as a drive source. Steam discharged from the ejector 40 is supplied to the steam header 29.

  The steam header 29 is configured to receive steam that has been pressurized by the compressor 13 serving as a steam compressing means and steam from the ejector 40 and send it to the steam tube dryer 30.

  Here, the pressure measuring means P2 in the steam header (steam storing means) 29 is provided, and the load of the first steam generating means (heat pump 25) is sent by sending the measured pressure to the control device of the heat pump compressor 27. Adjust.

  On the other hand, the exhaust gas from the steam boiler 19 is processed by the exhaust gas processor 21 via the heat exchanger 20 and discharged to the outside. The heat exchanger 20 is configured to heat the exhaust gas from the dry exhaust gas wet scrubber 9 and send it to the steam tube dryer 30.

  Next, specific steps in the heat treatment facility will be described.

  For example, sewage sludge with a water content of 75% to 85% is supplied to the sludge supply pump 1, and this sewage sludge is sent to the mixer 2 and mixed with the dried product S <b> 1 to obtain a workpiece S <b> 0 having a water content of about 30%. . The object to be processed S0 containing moisture and organic matter is supplied to a steam tube dryer 30 which is an indirect heating type dryer, and the moisture of the mixed product S0 is dried to about 10%, for example, to obtain a dried product S. By mixing the dried product S1 with the object to be treated before drying, the apparent moisture of the object to be treated is reduced, and a blockage trouble due to the adhesion characteristic of sludge can be avoided.

  At this time, a dry exhaust gas G having a dew point of desirably 80 ° C. to 100 ° C. (about 85 ° C. is optimal) is discharged from the steam tube dryer 30, and the dry exhaust gas G is composed of, for example, a plurality of stages. It is sent to a dry exhaust gas wet scrubber 9 to be cooled and dehumidified. The higher the gas temperature at the lowermost outlet of the dry exhaust gas wet scrubber 9, the higher the amount of heat recovered by the dry exhaust gas wet scrubber 9 when the gas temperature is high. Will decline. At this time, it is preferable to operate so that the gas temperature at the lowermost outlet of the dry exhaust gas wet scrubber 9 is 60 ° C to 80 ° C.

  The carrier gas used in the steam tube dryer 30 is discharged from the steam tube dryer 30 as a dry exhaust gas G. The dry exhaust gas G is processed by the dry exhaust gas wet scrubber 9 to heat the dry exhaust gas G to the scrubber circulating water. To recover heat. And although there is no restriction | limiting in particular in the final stage exit temperature of this dry exhaust gas wet scrubber 9, About 30-40 degreeC is suitable. The carrier gas discharged from the wet scrubber 9 is supplied to the afterburner 18 through a blowing means such as a circulation blower, and the others are heated and then recycled.

  The scrubber circulating water recovered at the lowest stage of the dry exhaust gas wet scrubber 9 is heat-exchanged with the heat medium circulating in the heat pump 25 via the heat pump heater 10 and the evaporator 26. The heat medium that has received the heat is compressed by the heat pump compressor, and then heat-exchanged with saturated water in the 27 condenser 28. The saturated water is heated to become compressed water, flushed by the flash tank 12, and becomes saturated water and saturated steam at the pressure in the flash tank. The vapor pressure (internal pressure of the flash tank 12) generated by the heat pump 25 is about 0.1 to 0.25 MPa. However, considering the coefficient of performance (COP) of the heat pump, it is economical that the vapor pressure is up to about 0.2 MPa. The steam generated from the flash tank 12 is partly pressurized by the compressor 13 and the remaining part is pressurized by the ejector 40 and sent to the steam header 29. In the compressor 13, the load is adjusted so that the vapor pressure (internal pressure of the flash tank 12) generated by the heat pump 25 becomes a predetermined pressure. Note that it is not necessary to use both the compressor 13 and the ejector 40, and either one may be used.

  On the other hand, the dried product S discharged from the steam tube dryer 30 is sent to the sieve 5 by the transfer conveyor 4 and sieved into large particles and small particles. Part of the sieved large particles is crushed by the crusher 6 and then sent to the return hopper 7a. Further, the sieved small particles are directly sent to the return hopper 7a. The dried product S1 cut out by the return hopper 7a is sent to the mixer 2 by the return conveyor 8 and then mixed with the sewage sludge (object to be treated).

  Apart from these, the remainder of the large sieving particles is sent to the dry product hopper 7b, cut out, and then sent to, for example, an external heat kiln type carbonization furnace 16 by the dry product transfer conveyor 15, in the carbonization furnace 16 It is pyrolyzed at 250 ° C. to 600 ° C. to become carbide and combustible gas N. At this time, since the thermal decomposition is an endothermic reaction, it is indirectly heated by hot air generated by burning fuel in the hot air generator 17 for carbonization furnace. And the carbide | carbonized_material discharged | emitted from the carbonization furnace 16 is cooled with the cooler which is not shown in figure, Then, it is carried out, On the other hand, combustible gas N is combusted with the afterburner 18. FIG.

  Next, the exhaust gas generated by burning the combustible gas N in the afterburner 18 is supplied to the boiler 19 through a supply path such as a duct. The boiler 19 generates steam of 0.8 MPa or more, preferably 1.6 MPa or more, by the boiler 19. However, when the ejector 40 is not used, steam of 0.5 MPa or more, preferably 0.7 MPa or more is generated.

  The steam generated in the boiler 19 is supplied as a drive source to an ejector 40 provided in a path communicating with the steam header 29. The supplied steam sucks the steam generated by the heat pump 25 with the ejector 40 and pressurizes the steam, and then the steam is supplied to the steam header 29.

  On the other hand, the exhaust gas discharged from the boiler 19 conveys the exhaust gas of the dry exhaust gas wet scrubber 9 through the path 24 and heats it with the heat exchanger 20 to convert the exhaust gas of the dry exhaust gas wet scrubber 9 into the steam tube dryer. 30 is used as a carrier gas. Thereafter, the exhaust gas from the boiler 19 is processed by the exhaust gas processor 21 and then released to the atmosphere.

  On the other hand, the steam boosted from the compressor 13 is also supplied to the steam header 29. The steam stored in the steam header 29 is maintained at a preset pressure (preferably 0.2 MPa to 0.4 MPa) and supplied to the steam tube dryer. Note that the vapor pressure stored in the steam header 29 is measured by the pressure sensor P <b> 2 and used for controlling the heat pump 25.

  The set pressure of the steam header 29 is determined by measuring the moisture of the dried product with a moisture meter arranged at the rear stage of the dryer, and adjusting the set value so that the moisture becomes a predetermined numerical value. The higher the pressure of the steam supplied to the dryer, the higher the drying efficiency, so lower the steam setting pressure if you want to lower the moisture in the dried product, and increase the steam setting pressure if you want to increase the moisture. adjust.

  Further, since a correlation is recognized between the temperature of the dried product and the moisture of the dried product, the set pressure of the steam supplied to the dryer can be set according to the temperature of the dried product. An example of the relationship between the temperature of the dried product and the moisture of the dried product is shown in FIG. What is necessary is just to measure directly the temperature of the dry matter discharged | emitted from the measurement of the internal temperature by the thermometer measured by the steam tube dryer, and the steam tube dryer.

  For the pressure setting of the steam header 29, either the moisture of the dried product or the temperature of the dried product may be used, or both may be used by weighting.

  If the pressure of the steam header 29 does not reach a predetermined pressure even by the control of the heat pump 25, the second pressure control is performed to increase the amount of fuel supplied to the afterburner 9 and increase the amount of steam generated in the boiler 19.

  As shown in FIG. 3, the second embodiment is an example in which an incline disc dryer 70 which is a disc type dryer is used instead of the steam tube dryer 3.

  Note that the apparatus and process not described below are the same as those in the first embodiment.

  For example, sewage sludge with a water content of 75 to 85% is supplied from the sludge supply pump 1 to the charging side of the ink-jet disk dryer 70 to obtain a dried product S with a water content of about 10 to 40%.

  The dry exhaust gas G discharged from the ink-jet disk dryer 70 is supplied to the dry exhaust gas wet scrubber 9, and the heat recovered by the dry exhaust gas wet scrubber 9 is heat-exchanged in the heat pump heater 10, so that the heat source of the heat pump 25 is heated. It is said.

  In this example, the dry exhaust gas wet scrubber 9, the heat pump heater 10, and the heat pump 25 constitute the first steam generating means. The first steam is generated in the first steam generating means, and the first steam is sent to the compressor 13 as the first pressure increasing means and compressed. The compressed steam is sent to a steam header 29 as steam storing means. The configuration of the heat pump 25 is the same as that of the first embodiment, and includes an evaporator 26, a heat pump compressor 27, and a condenser 28. The heat pump compressor includes a control device that performs variable voltage variable frequency control (VVVF control), and controls the amount of steam generated by the heat pump 25 according to the pressure in the steam header 29.

  From the steam header 29, steam is sent to the ink-jet disk dryer 70 via the path 22 and used as steam for heating. Some are used or discarded as traces.

  On the other hand, the dried product S in the ink-lined disk dryer 70 is discharged onto the dried product transfer conveyor 4 on the lower side of the discharge side, and then sent to the dried product hopper 7b.

  The dried product S is discharged from the lower part of the dried product hopper 7b and formed into pellets having a diameter of about 5 to 6 mm by the granulator 50. The carbonization furnace 16 is charged and heated (heated).

  The steam header 29 is configured to receive the steam whose pressure has been increased by the compressor 13 as the steam compression means and the steam generated by the steam boiler 19 and to send the steam to the ink-jet disk dryer 70.

  Here, pressure adjusting means for adjusting the pressure P2 in the steam header 29 based on the load of the first steam generating means (heat pump 25) is provided.

  Next, specific steps in the heat treatment facility will be described.

  The sewage sludge is supplied from the sludge supply pump 1 to an incline disc dryer 70 which is an indirect heating type dryer, and the moisture is dried to about 10 to 40%, for example, to obtain a dried product S.

  At this time, a dry exhaust gas G having a dew point of desirably 80 ° C. to 100 ° C. (about 85 ° C. is optimum) is discharged from the ink-disc disk dryer 70. The dry exhaust gas G is composed of, for example, a plurality of stages. The dried exhaust gas wet scrubber 9 is cooled and dehumidified. The higher the gas temperature at the lowermost outlet of the dry exhaust gas wet scrubber 9, the more economical the steam can be recovered by the heat pump 25. However, when the gas temperature is high, the amount of heat recovered by the dry exhaust gas wet scrubber 9 is descend. At this time, it is preferable to operate so that the gas temperature at the lowermost outlet of the dry exhaust gas wet scrubber 9 is 60 ° C to 80 ° C.

  The carrier gas used in the incline disc dryer 70 is discharged from the incline disc dryer 70 as a dry exhaust gas G. The dry exhaust gas G is treated with the dry exhaust gas wet scrubber 9, and the dry exhaust gas G is circulated into the scrubber circulating water. The heat is recovered by transferring the heat. And although there is no restriction | limiting in particular in the final stage exit temperature of this dry exhaust gas wet scrubber 9, About 30-40 degreeC is suitable.

  The heat recovered at the lowermost stage of the dry exhaust gas wet scrubber 9 is transferred to the heat pump 25 via the heat pump heater 10 and becomes a heat source for generating steam. The vapor pressure generated by the heat pump 25 is about 0.1 to 0.25 MPa. However, considering the coefficient of performance (COP) of the heat pump, it is economical that the vapor pressure is up to about 0.2 MPa. The steam generated by the heat pump 25 is compressed by the compressor 13 to be pressurized and sent to the steam header 29.

  On the other hand, the dried product S that has been dried by the ink-lined disk dryer 70 is sent to the dry product hopper 7b by the transfer conveyor 4 and formed into pellets of about φ5 to 6 mm by the granulator 6.

  The dried molded product S2 is sent to the carbonization furnace 16 by the dry product transfer conveyor 15, and is pyrolyzed at 250 ° C to 600 ° C to become carbide and combustible gas N.

  Next, the exhaust gas generated by burning the combustible gas N as the combustion material in the afterburner 18 is supplied to the boiler 19 through a supply path such as a duct. Due to the heat retained by the exhaust gas, the boiler 19 generates steam of 0.7 MPa or more, preferably 0.5 MPa or more. At this time, exhaust gas discharged from the boiler 19 conveys the exhaust gas of the dry exhaust gas wet scrubber 9 through the path 24 and heats it with the heat exchanger 20, and the exhaust gas of the dry exhaust gas wet scrubber 9 is inclined. The disc dryer 70 is used as a carrier gas. Thereafter, the exhaust gas from the boiler 19 is processed by the exhaust gas processor 21 and then released to the atmosphere.

  On the other hand, the compressor 13 boosts the pressure. Finally, preferably, pressurized steam of 0.2 MPa to 0.8 MPa is supplied to the ink-jet disc dryer 70, and the mixed product S0 is dried to become a dry product S by the ink-jet disc dryer 70.

  In the first and second embodiments, heat is recovered from the dry exhaust gas G to obtain steam. As a method for recovering heat from the dry exhaust gas G at this time, the dry exhaust gas G is dried exhaust gas wet scrubber in this embodiment. Although the method of transferring the heat of the dry exhaust gas G to the scrubber circulating water and recovering the heat as circulating water was used by treating with 9 etc., the method of recovering the heat directly from the dry exhaust gas G with a heat exchanger or the like may be used. .

  Furthermore, as a method of obtaining steam from the recovered heat of the dried exhaust gas G, a method of generating recovered steam by supplying the recovered heat to a steam generating heat pump and generating a steam of about 0.1 to 0.25 MPa is used in the present embodiment. You may use the method of obtaining about 0.015-0.05 MPa vapor | steam with the water evaporator which uses collection | recovery heat as a heat source.

  The upper limit value of the temperature of the heat source water recovered from the dried exhaust gas is almost equal to the dew point of the dried exhaust gas G. On the other hand, since the coefficient of performance (COP) of the heat pump increases as the temperature of the heat source water supplied to the heat pump increases, it is advantageous to increase the dew point of the dry exhaust gas. However, when the dew point of the dry exhaust gas G is increased, the temperature of the product becomes almost equal to the dew point of the dry exhaust gas G by constant rate drying in the indirect heating type dryer. The drying capacity of the machine is reduced. Accordingly, there is an optimum dew point of the dry exhaust gas G. Here, the dew point of the dry exhaust gas G is preferably 80 ° C. to 100 ° C., although it depends on the amount of water evaporated by the indirect heating dryer.

  The first steam is compressed by the compressor 13 and the pressure is increased. At this time, the type of the compressor 13 is not particularly limited, but a screw compressor that does not require countermeasures against mist is suitable. In this case, the compression ratio (ratio between the discharge pressure and the suction pressure) in the compressor 13 is economical in the range of 2 to 10. Roots blowers and multistage blowers can also be used.

  The heat treatment of the dried product S is not limited to the carbonization treatment, and for example, a gasification treatment, an incineration treatment, or the like can be employed.

  The boiler 19 is a known waste heat boiler, and generates high-pressure steam from the combustion exhaust gas N generated from the afterburner. The fuel used as the combustion material for the afterburner is not particularly limited, and any of a pyrolysis product combustible gas N, carbide, and other fuels may be used. Note that as the combustible gas N supplied to the boiler 19, exhaust gas obtained by burning the fuel may be used directly, or exhaust gas burned by a gas turbine, a gas engine, or the like may be used.

  By the way, when a process for discharging high-temperature exhaust gas such as incineration of a product to be dried is performed, the discharged high-temperature exhaust gas can be directly supplied to the waste heat boiler.

  The present invention can be applied to drying of woody biomass, organic waste, etc., as well as drying of resins, foods, organic substances and the like.

5 Sieve 6 Crusher 7a Return hopper 7b Dry hopper 8 Return conveyor 9 Dry exhaust gas wet scrubber 10 Heat pump heater 12 Flash tank 13 Compressor 16 Carbonization furnace (heat treatment equipment)
18 Afterburner 19 Boiler 25 Heat pump 26 Evaporator 27 Heat pump compressor 28 Condenser 29 Steam header 30 Steam tube dryer (indirect heating dryer)
40 Ejector 50 Granulator 70 Inclined disk dryer

Claims (5)

In a heat treatment facility including an indirect heating type dryer using steam as a heat source for drying a treatment object containing moisture and organic matter, and a heat treatment facility for heating the treatment object dried by the dryer,
First steam generating means for recovering the retained heat of the dry exhaust gas generated by the indirect heating dryer and generating first steam;
Second steam generating means for generating second steam using at least one of combustible gas or combustion exhaust gas generated in the heat treatment facility as a heat source;
Vapor compression means for mechanically compressing the first vapor;
Steam storing means for temporarily storing the compressed steam by the steam compressing means and the second steam by the second steam generating means;
Steam supply means for supplying the stored steam from the steam storage means as a heating source for drying the object to be processed by an indirect heating dryer;
Pressure measuring means in the vapor storage means;
Pressure control means for controlling the first steam generation means based on the pressure measurement value of the pressure measurement means,
Heat treatment equipment characterized by that. Dry matter moisture measurement result measured by dry matter moisture measuring means for measuring moisture content of the dried matter dried by the indirect heating dryer, and dried matter measured by the dry matter temperature measuring means for measuring the temperature of the dried matter. A steam storage pressure setting means for determining a set value of the internal pressure of the steam storage means based on at least one of the temperature measurement results;
The heat treatment equipment according to claim 1, wherein the pressure control means controls the first steam generation means so that the pressure measurement value becomes the set value.   The heat treatment equipment according to claim 1 or 2, wherein the condensate of the steam in the indirect heating dryer is returned to at least one of the first steam generating means and the second steam generating means as a steam source. In a heat treatment method including an indirect heating type dryer using steam as a heat source for drying an object to be treated containing moisture and organic matter, and a heat treatment facility for heating the object to be treated dried by the dryer,
A first steam generation step of recovering the retained heat of the dry exhaust gas generated in the indirect heating dryer to generate the first steam;
A second steam generating step for generating a second steam using at least one of a combustible gas or combustion exhaust gas generated in the heat treatment facility as a heat source;
A vapor compression step of mechanically compressing the first vapor;
A steam storage step for temporarily storing the compressed steam by the vapor compression step and the second steam by the second steam generation step;
A steam supply process for supplying the stored steam from the steam storage process as a heating source for drying the object to be processed by an indirect heating dryer;
A pressure control step of controlling the first steam generation step so that the pressure in the storage means of the steam storage step becomes a predetermined set value,
The heat processing method characterized by the above-mentioned. Adjusting the set value of the pressure in the vapor storage means based on at least one of the moisture or temperature of the dried product dried by the indirect heating dryer;
The heat treatment method according to claim 4 .

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