JP2007132552A - Heating device for waste gypsum - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating device which efficiently creates β-hemihydrate gypsum from waste gypsum. <P>SOLUTION: The heating device for the waste gypsum comprises: a screw type supply portion for transporting the waste gypsum supplied from a supply hopper; a cylindrical rotating body receiving the waste gypsum from the supply portion, and rotated and driven; a high-frequency heating portion installed in adjacent to an outer peripheral face of the rotating body at an outer side of the rotating body; a discharge portion for discharging the β-hemihydrate gypsum from a terminal end of the cylindrical rotating body; and an air discharging means connected near the terminal end of the cylindrical rotating body and discharging the steam generated in the rotating body. The high-frequency heating portion is mounted at a lower side of the rotating body in a state of being divided into plural sections, a gypsum stirring blade having an approximately L-shaped cross-section is mounted on an inner wall surface of the cylindrical rotating body, and the gypsum lifted to an upper side of the rotating body by the stirring blade in accompany with the rotation of the rotating body falls to an upstream side in the rotating direction, of a lower portion in the rotating body. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the present invention, for example, dihydrate gypsum obtained by crushing waste gypsum board and removing unnecessary materials such as paper, or dihydrate gypsum obtained by crushing waste gypsum of pottery type, dental shape, model, etc., is put in a cylindrical rotating body. The present invention relates to a heating device for waste gypsum which is heated at high frequency from the outside and heated and dehydrated into β hemihydrate gypsum or anhydrous gypsum capable of hydration.

  As a technology to obtain calcined gypsum (type 3 anhydrous gypsum, etc.) that hydrates and cures from waste gypsum board, conventionally, waste gypsum board is crushed by compression, impact, shear, friction and cutting, and the crushed waste gypsum is shaken or rotated. The waste gypsum (dihydrate gypsum) separated by paper with a sieve or the like is heated at 280 to 320 ° C. for 1 to 4 hours and dehydrated to type 3 anhydrous gypsum, and the paper in the gypsum and the organic admixture Has been proposed (Patent Document 1).

  As a rotary barrel type incinerator drying furnace, an apparatus (Patent Document 2) that blows hot air from a burner directly into a cylindrical rotating body to dry an object to be heated, a single high-frequency heating unit is disposed below the rotating drum. A batch processing type drying device (Patent Document 3) for drying an object to be heated by a high-frequency heating unit, winding a high-frequency heating coil around the entire circumference in the circumferential direction outside the cylindrical rotating body, and a plurality of units from the outside of the cylindrical rotating body A heating furnace (Patent Documents 4 and 5) that continuously processes an object to be heated in a high-frequency heating section is proposed.

Japanese Patent No. 3221940 JP 2001-327845 A JP 59-176573 JP 57-115670 A JP-A-11-226542

  By the way, in the technique of the above-mentioned Patent Document 1, paper is mixed in waste gypsum that has passed through the sieve, and unless the temperature is controlled below the temperature at which the paper and the organic admixture in the gypsum are carbonized, carbide is added to the heated dehydrated gypsum. There is a problem that is mixed and discolored.

  In an apparatus that blows hot air of a burner directly into the inside of a cylindrical rotating body as in Patent Document 2, a large variation in temperature distribution occurs in the rotating body. Therefore, when dihydrate gypsum is used as an apparatus for heating and dehydrating, The heat dehydration state is not stable, and there is a problem that the quality of the product varies as an apparatus for heat dehydrating dihydrate gypsum to β-half water gypsum or type 3 anhydrous gypsum capable of hydration. Moreover, according to the apparatus of the same literature 2, when the temperature of some gypsum becomes 360 degreeC or more in the burner blowing part which is high temperature, it will become 2 type anhydrous gypsum which is hard to hydrate, and a hydration reaction will vary. Furthermore, there is a problem of discoloration due to mixing of soot or the like due to combustion of fossil fuel, and a problem that the apparatus such as a dust collector is attached on the exhaust side for the dispersion treatment of the powder gypsum with hot air.

  Patent Document 3 is a drying device in which a high-frequency heating unit is disposed on the lower side of a rotating drum and batch processing is performed with a single high-frequency heating unit, but the scraping plate in the rotating drum is a vertical flat plate, Non-heated material can fall only in a part of the rotation direction with respect to the position of the lower high-frequency heating part, and in the case of gypsum with a gap between particles, an induction heating is generated by generating an eddy current in the rotary drum with a high-frequency heating coil. The heat transfer area at the high temperature part in contact with the gypsum decreases and the heat transfer rate deteriorates, and the thickness of the object to be heated increases from the lowest part in the rotation direction to a quarter of the downstream. In this case, the heat-dehydrated water vapor is difficult to escape from the upper surface of the gypsum, resulting in a poor heat transfer rate.

  The above Patent Documents 4 and 5 are heating furnaces that continuously process an object to be heated by a plurality of high-frequency heating units from the outside of a cylindrical rotating body, but high-frequency heating is performed on the entire circumference in the circumferential direction outside the cylindrical rotating body. Coil is wound, and in the case of gypsum, it is necessary to seal the water vapor generated by heat dehydration in the rotational sliding between the cylindrical rotating body and the both-end fixed part, and the high-frequency heating coil should be arranged at the lower part On the other hand, if it is wound around the entire circumference, there is a problem that it takes time to assemble and remove.

  The present invention has been made in view of the above-described conventional problems. A plurality of high-frequency heating units attached to the lower side of a cylindrical rotating body are used to efficiently heat dihydrate gypsum and to control two water by temperature control. The object is to efficiently obtain β-half-water gypsum or anhydrous gypsum that is not mixed with gypsum. It is another object of the present invention to save energy by reducing the amount of heat generated from the water vapor generated by heat dehydration of gypsum and the heat dehydration gypsum discharged and the amount of heat released. It is another object of the present invention to provide a gypsum heating device having a simple device configuration.

In order to solve the above problems, the present invention
First, in a waste gypsum heating apparatus that heats crushed waste gypsum, a screw-type supply unit that conveys the waste gypsum supplied from a supply hopper, and the supply of the waste gypsum from the screw-type supply unit A cylindrical rotating body that is rotationally driven by the driving means in a state where it is inclined and installed, and a high-frequency heating unit that is installed in the vicinity of the outer peripheral surface of the rotating body outside the cylindrical rotating body, A waste gypsum heating apparatus comprising: a discharge unit that discharges β hemihydrate gypsum or anhydrous gypsum from a terminal end of a cylindrical rotating body; and an exhaust unit that exhausts water vapor generated in the cylindrical rotating body, The heating unit is divided into a plurality of positions at a position facing the lower outer peripheral surface of the rotating body, and a plurality of gypsum stirring blades having a substantially L-shaped cross section are provided on the inner wall surface of the cylindrical rotating body. The above stirring blade as the body rotates Is formed using the heating device of the waste gypsum, characterized in that the gypsum lifted to the rotating body upper is obtained by construction so as to fall in the rotation direction upstream side of the rotating body bottom by.

  With this configuration, β hemihydrate gypsum or anhydrous gypsum in which dihydrate gypsum is not mixed with temperature control by efficiently heating dihydrate gypsum by a plurality of high-frequency heating units attached to the lower side of the cylindrical rotating body. Can be obtained efficiently. Moreover, gypsum can be efficiently stirred by the stirring blade in the cylindrical rotating body. The exhaust means includes, for example, a hollow pipe (9a), an outer passage (12a), an exhaust pipe (12 '), and the like of the supply device (12). This exhaust means is preferably provided in the vicinity of the start end of the cylindrical rotating body, in the vicinity of the start end or in the vicinity of the end, or in the vicinity of the start end and in the vicinity of the end.

  Secondly, the screw-type supply unit includes a supply pipe including a screw that conveys waste gypsum from the supply hopper into the cylindrical rotating body, and water vapor generated in the rotating body as a conveying direction of the gypsum. A discharge pipe that discharges in the opposite direction; and the supply pipe and the discharge pipe are configured to be able to exchange heat via a heat transfer surface. It is comprised by the heating apparatus of the waste gypsum of description.

  If comprised in this way, the exhaust heat utilization from heat | fever dehydration gypsum can be aimed at, and energy saving can be implement | achieved by reducing the emitted-heat amount. Further, a drainage structure of condensed water (for example, the condensation tank (14) in FIG. 1, the heat exchange tank (43) in FIG. 8) and a washing structure (for example, the washing of the heat exchange tank 43 in FIG. 8) are provided in the water vapor passage of the discharge pipe. Structure) can also be provided.

  Third, a heat exchange means for heating the heat medium using the heat of the water vapor exhausted from the exhaust means is provided, and the screw-type supply unit disposes the waste gypsum from the supply hopper into the cylindrical rotating body. A supply pipe provided with a screw for conveying, and a discharge pipe for discharging the heat medium in a direction opposite to the conveying direction of the gypsum, and the supply pipe and the discharge pipe are further connected via a heat transfer surface. The waste gypsum heating apparatus according to the first aspect is configured to be capable of heat exchange.

  Fourth, a dust collecting unit for collecting gypsum dust in water vapor exhausted from the exhaust unit is provided, and the screw-type supply unit is a screw that conveys waste gypsum from the supply hopper into the cylindrical rotating body. And a discharge pipe that discharges water vapor that has passed through the dust collecting portion in a direction opposite to the direction of transport of the gypsum, and the supply pipe and the discharge pipe further include a heat transfer surface. It is comprised so that heat exchange can be carried out through, It is comprised by the heating apparatus of the waste gypsum of the said 1st characterized by the above-mentioned.

  Fifth, a fan for supplying outside air to the cylindrical rotating body is provided, and the heated and dehydrated gypsum discharge part in the cylindrical rotating body is cooled with the above-mentioned supply air and supplied with air. The waste gypsum heating apparatus according to any one of the first or fourth aspect is provided with a heat exchange mechanism that heats the gypsum after the heat dehydration.

  If comprised in this way, air supply can be heated, cooling the dehydrated gypsum after discharge | emission, and the temperature fall in a cylindrical rotary body can be prevented.

  Sixth, a non-contact type temperature sensor capable of measuring the temperature of the outer peripheral surface position on the upstream side in the rotation direction or the downstream side in the rotation direction of the cylindrical rotating body is provided corresponding to each of the high-frequency heating units, and the temperature sensor Based on the temperature of the outer peripheral surface of the rotating body measured in step 1, the output of the high-frequency heating unit and the amount of gypsum supplied by the screw-type supply unit can be controlled. The waste gypsum heating device according to any one of the above.

  If comprised in this way, an efficient heat processing can be performed by controlling a high frequency heating output, a gypsum supply amount, etc. at the time of the supply start of gypsum, etc. based on the detection temperature of the said temperature sensor, for example. .

  Seventh, the plaster agitating blade is composed of a joining plate portion and a substrate portion that form a substantially L-shaped cross section, and further on the edge of the substrate portion toward the joining plate portion with respect to the substrate portion. It has a projecting plate portion projecting at a predetermined angle, and a space is provided between both end portions of the plaster stirring blade and the left and right closed wall surfaces of the cylindrical rotating body. It is comprised by the heating apparatus of the waste gypsum in any one of the said 1st-6th characterized.

  If comprised in this way, based on rotation of a rotary body, a gypsum can be lifted with a gypsum stirring blade, and can be dropped from the upper part to the rotation direction upstream of a rotary body, and this realizes efficient heating of a plaster Can do.

  Eighth, the cylindrical rotating body and the high-frequency heating unit are covered with a heat insulation case, and a partition plate is provided near the upper portion of the high-frequency heating unit inside the heat insulation case. The internal space is divided into an installation space for a high-frequency heating unit and a space on the cylindrical rotating body side, and is constituted by the waste gypsum heating device according to any one of the above first to seventh aspects It is.

  If comprised in this way, it can prevent that the high temperature air in the case for heat insulation flows to the high frequency heating part side by a convection, and can improve the cooling efficiency of a high frequency heating part.

  Ninth, a ceramic fiber heat insulating sheet having a thickness of 9 mm or less is wrapped around and fixed to the outside of the cylindrical rotating body with a heat-resistant tape or a heat-resistant adhesive, and a non-contact type temperature sensor on the outer periphery of the rotating body in the sheet is used. It is constituted by the waste gypsum heating device according to any one of the first to eighth aspects, wherein a portion including the measurement point is cut out.

  If comprised in this way, the temperature fall in a cylindrical rotary body can be prevented efficiently.

  Tenth, the length of the cylindrical rotating body in the axial direction of each high-frequency heating coil of the plurality of high-frequency heating units is set so that the coil on the discharge side is longer than the coil on the supply side of the cylindrical rotating body. The waste gypsum heating apparatus according to any one of the first to ninth aspects, which is configured.

  With this configuration, the amount of high-frequency heating per unit length in the longitudinal direction of the cylindrical rotating body of the high-frequency heating coil can be made lower on the discharge-side coil than on the supply-side coil. It becomes easy to carry out, and high-quality heat-dehydrated gypsum can be obtained.

  Eleventh, an inclined plate is provided inside the cylindrical rotating body, and the gypsum dropped from the plaster agitating blade is moved on the upper surface of the inclined plate and dropped from the installation position of the high-frequency heating unit to the upstream side in the rotation direction. The waste gypsum heating device according to any one of the above first to tenth features.

  By comprising in this way, the gypsum in a rotary body can be reliably dropped and stirred to the upstream side of a rotation direction, and an efficient heat processing of gypsum can be performed.

  12thly, a burner combustion part is attached to the outer side of the fixed end on the end surface side of the cylindrical rotating body, and a burner radiating cylinder is fixed and attached to the cylindrical rotating body from the fixed end, and hot air from the burner is passed through the burner radiating cylinder. The heating of the first waste gypsum, wherein the gypsum is indirectly heated, the combustion gas is exchanged with the gypsum in the supply apparatus and exhausted, and the burner heating is used to heat the gypsum on the supply side of the cylindrical rotating body. Consists of devices.

  If comprised in this way, efficient heating can be implement | achieved, without producing the dispersion | variation in temperature distribution, combining burner heating. The supply device is, for example, the supply device (63) in FIG.

  Thus, according to the present invention, high-quality β hemihydrate gypsum can be obtained.

  Furthermore, water vapor generated by heating and dehydrating gypsum can be used for heating gypsum, and energy saving can be realized.

  Also, a waste gypsum heating device having a simple device configuration can be obtained.

  Hereinafter, the structure of the heating apparatus for gypsum according to the present invention will be described in detail.

  In FIG. 1, 1 is a hollow cylindrical rotating body that heats and dehydrates gypsum inside, and the material of the cylindrical rotating body 1 is a cylindrical steel plate (having a high relative permeability), or the rust of the steel plate is transformed into gypsum. In order to avoid contamination, a steel plate on the outside and a stainless steel plate with a small relative permeability on the inside are joined, or a stainless steel plate is joined on the inside and outside of the steel plate, and the surface of the steel plate is coated with ceramic or resin. Use things.

  The cylindrical rotating body 1 has a cylindrical shape, and is supported at four or more points by rollers 2 provided near both sides of the lower portion of the rotating body 1, and a rotation driving motor (driving means) 3 via a gear or a chain 2a. Then, the roller 2 is rotated, and the cylindrical rotating body 1 is rotated in the arrow m direction by the roller 2. The rotational drive motor 3 is configured such that the rotational speed can be variably controlled by an inverter.

  The cylindrical rotating body 1 is provided with a downward gradient from the supply side A toward the discharge side B at an angle of 0 to several degrees. Thereby, there is a height difference between the supply side A and the discharge side B of the rotator 1 and the gypsum flows from the supply side to the outlet side.

  A lifting portion (gypsum stirring blade) 4 is attached to the inner surface of the cylindrical rotating body 1 by welding or the like in the longitudinal direction. The number of the lifting portions 4 is 8 to 16, and they are arranged almost evenly in the circumferential direction.

  Dihydrate gypsum 7 is stored in the supply hopper 6, the dihydrate gypsum stored by periodically operating the vibrator 8 is dropped on the screw conveyor 9, and the dihydrate gypsum is rotated in a cylindrical shape by the rotation of the screw conveyor 9. Supply to the body 1. The central axis of rotation of the screw conveyor 9 is constituted by a hollow pipe 9a, and the screw conveyor 9 drives the hollow pipe 9a with a motor 10 via a gear or a chain 10a, thereby converting the dihydrate gypsum into the cylindrical shape. It is rotationally driven in a direction that can be supplied into the rotating body 1. The motor 10 is capable of variable speed control by an inverter, and is configured so that the amount of dihydrate gypsum supplied to the rotating body 1 can be controlled by controlling the rotational speed of the screw conveyor 9. .

  A material detection sensor 11 such as a capacitance type is provided at the outlet portion of the dihydrate gypsum of the supply hopper 6 so that it can be detected whether or not the dihydrate gypsum is stored in the hopper 6.

  Reference numeral 12 denotes a dihydrate gypsum supply device (screw type supply unit) including the screw conveyor 9 and the hollow pipe 9a, and has a double pipe structure as a whole. The outer pipe (discharge pipe) of the supply device 12 is formed with an outer passage 12a through which water vapor generated by heating and dehydration in the cylindrical rotating body 1 passes, and the inner pipe (supply pipe) is provided with two pipes from the hopper 6. An inner passage 12b through which water gypsum is sent by the screw conveyor 9 is formed. A gap between the supply device 12 and the connecting portion 1a at the outer peripheral edge of the cylindrical rotating body 1 is sealed with a packing 12c.

  The water vapor in the rotating body 1 during the heat drying is exhausted through the hollow pipe 9 a of the screw conveyor 9, and the rotating hollow pipe 9 a is connected to the non-rotating hose 13 a through the rotary joint 13. Therefore, the hollow pipe 9a also functions as an exhaust pipe. Here, the boundary surface between the outer passage 12a and the inner passage 12b and the boundary surface between the inner passage 12b and the hollow pipe 9a are heat transfer surfaces.

  A paddle 9b is attached to the outer surface of the hollow pipe 9a or the screw conveyor 9 so as to rotate integrally with the pipe 9a or the screw conveyor 9, the gypsum transferred by the screw conveyor 9 is stirred in the passage, and the steam passage and heat transfer It is also possible to improve the heat transfer through the surface to the gypsum.

  The water vapor that has passed through the hose 13a and the outer passage 12a and the condensed water partially condensed enter the condensation tank 14 and the condensed water accumulates, and is naturally exhausted to the outside air from the exhaust outlet 15a, or is forcedly exhausted by installing an exhaust fan 15 To do.

  A terminal fixing lid 16 is fixedly installed at the end of the cylindrical rotating body 1, and a gap between the cylindrical rotating body 1 and the terminal fixing lid 16 is sealed with a packing 16a.

  The heated and dehydrated gypsum falls from the main body discharge port 17 at the end of the cylindrical rotating body 1, is transferred by the rotation of the discharge screw conveyor 19 in the discharge device 18, and is discharged from the upper discharge port 21. It will be stored. The discharge screw conveyor 19 is rotated by a motor 20.

  An exhaust fan (fan) 15 is provided in the condensate tank 14, and the exhaust fan 15 forcibly exhausts the inside of the cylindrical rotating body 1 to a negative pressure. In this case, outside air is supplied (input) into the cylindrical rotating body 1 from the air supply port 23 provided in the upper portion of the discharge device 18 through the inner surface upper portion of the discharge device 18 and the upper surface of the discharge screw conveyor 19. Heated dehydrated gypsum whose temperature at the main body discharge port (discharge unit) 17 is 130 ° C. or higher and the supply air (air) from the supply port 23 perform heat exchange in the discharge device 18 and the temperature of the supply air (air) The heated dehydrated gypsum is cooled by the supply air. In this manner, the heat exchange mechanism is configured by the exhaust fan 15, the discharge device 18, the screw conveyor 19, the air supply port 23, and the like.

  In order to exhaust the water vapor in the cylindrical rotating body 1 from the terminal portion, an exhaust pipe 12 ′ may be connected to the upper portion of the terminal fixing lid 16 and connected to the outer passage 12 a of the supply device 12. The exhaust means is constituted by the hollow pipe 9a near the starting end of the rotating body 1, the outer passage 12a, the exhaust pipe 12 'near the end of the rotating body 1, and the like.

  Instead of the exhaust fan 15, an air supply fan (not shown) is provided at the air supply port 23 to forcibly supply air into the cylindrical rotating body 1 and exhaust the steam together with water vapor through the heat exchanger of the supply device 12. Is also possible.

  In FIG. 3, the high-frequency heating unit 5 has a spiral high-frequency heating coil 24 inside, and when a high-frequency current of several tens KHz is passed from a high-frequency inverter (not shown), the cylindrical rotating body 1 is subjected to electromagnetic induction action. An induced current flows and generates heat due to Joule heat. The clearance between the heating coil 24 of the high-frequency heating unit 5 and the metal surface of the cylindrical rotating body 1 is set about 10 to 17 mm apart depending on the cross section of the heating coil material, and the spiral heating coil 24 rotates in a cylindrical shape. A circular arc shape (elliptical shape) is formed while keeping a gap along the curvature of the body 1 (see FIG. 3B). Further, the upper surface of the heating coil 24 (on the side of the cylindrical rotating body 1) is coated with a heat resistant thin sheet 25 such as epoxy resin or Teflon (registered trademark) in order to prevent thermal deterioration of the heating coil 24 and molding of the heating coil 24. Cover the top to shut off heat.

  The heating coil 24 of the high-frequency heating unit 5 is usually a copper wire, and outside air is sucked from the filter 28 by a fan 27 and air-cooled. A porous molded plate sheet 26 having an air passage hole is provided below the heating coil 24, Exhaust air after cooling is exhausted through an exhaust duct 29. Further, a ferrite core or the like (not shown) is attached to the lower side of the porous molded plate sheet 26 to provide a magnetic shield.

It is also possible to use a hollow copper tube for the high-frequency heating coil 24 and circulate cooling water inside to cool it.

  By installing the high-frequency heating unit 5 on the lower side of the cylindrical rotating body 1, the clearance distance between the cylindrical rotating body 1 and the heating coil 24 can be easily adjusted by using the adjusting bolt 30 or the like, so that the mounting and manufacturing can be performed. It becomes easy to do.

  As shown in FIG. 4, the high-frequency heating unit 5 includes three high-frequency heating units 5a, 5b, and 5c. A plurality of these high-frequency heating units 5 a, 5 b, and 5 c are provided in the longitudinal direction of the cylindrical rotating body 1, and the heating amount and temperature distribution in the longitudinal direction of the cylindrical rotating body 1 can be controlled. In the present embodiment, three high-frequency heating sections 5 are provided, but the number can be appropriately increased or decreased depending on the total heating output, the length, diameter, etc. of the cylindrical rotating body 1.

The peak temperature of gypsum transition is affected by a small amount of impurities, additives, and heating speed, but dihydrate gypsum (CaSO ₄ · 2H ₂ O) to β hemihydrate gypsum (CaSO ₄ · 1 / 2H ₂ O). Endothermally absorbs and transitions to about 150 ° C. and releases crystal water of 3 / 2H ₂ O. In addition, it absorbs heat at about 170 ° C, removes 1 / 2H ₂ O crystal water and transfers to type 3 anhydrous gypsum (CaSO ₄ ), but returns to β-half water upon moisture absorption or water contact during hydration. Has no effect. When the temperature is further increased, it transitions to type 2 anhydrous gypsum (CaSO ₄ ) at about 360 ° C., but has a characteristic that it is difficult to hydrate.

  When producing heated dehydrated gypsum having a hydration action, it is necessary to control the temperature so as not to raise the temperature of the portion of the cylindrical rotating body 1 in contact with the gypsum so that type 2 anhydrous gypsum is not mixed.

  As shown in FIG. 4, when a plurality of high-frequency heating units 5a, 5b, and 5c have the same output, the high-frequency heating unit 5c on the gypsum discharge side is more cylindrically rotated than the high-frequency heating units 5a and 5b. The length of the body 1 in the longitudinal direction is long, and the maximum value of the high-frequency heating amount per unit length in the longitudinal direction is lowered.

  When producing β hemihydrate gypsum or type 3 anhydrous gypsum with hydration action, the high frequency heating sections 5a and 5b on the supply side dihydrate the dihydrate gypsum at about 150 ° C, so the temperature of the gypsum increases. Even if the maximum value of the high-frequency heating amount per unit length in the longitudinal direction of the cylindrical rotating body 1 is increased, the quality of the heated dehydrated gypsum does not deteriorate because the β-semihydration proceeds. On the other hand, since the ratio per unit volume of dihydrate gypsum decreases in the discharge-side high-frequency heating unit 5c, the temperature is controlled by reducing the maximum value of the high-frequency heating amount per unit length in the longitudinal direction. This makes it easy to improve the stability of the quality of the heated dehydrated gypsum.

  As shown in FIG. 4, the cylindrical rotating body 1 is entirely covered with a high-temperature heating unit 5 and a heat insulation casing 31. A heat insulating wall 32 ′ with a heat insulating agent 32 attached is provided on the inner surface of the heat insulating case 31, and a partition plate 33 is provided on the upper side of the high frequency heating unit 5 in the case 31 to provide high frequency heating in the case 31. The space between the part 5 side and the rotating body 1 side is divided, and the air in the lower part in the heat retaining casing 31 where the high-frequency heating part 5 that needs to be cooled is present and the air in which the temperature at the outer upper part of the cylindrical rotating body 1 is high It is possible to suppress the mixing by convection and reduce the heat radiation amount.

  A ceramic fiber heat insulating sheet 34 (34a to 34d) having a thickness of 9 mm or less is wound around and fixed to the outer periphery of the cylindrical rotating body 1 of FIG. 4 with a heat resistant tape or a heat resistant adhesive. Thereby, the amount of heat radiation from the cylindrical rotating body 1 itself can be reduced, and the amount of heat transferred to the high-frequency heating unit 5 that needs to be cooled can be reduced.

  The temperature of the outer peripheral wall of the cylindrical rotating body 1 is measured by an infrared non-contact sensor (non-contact temperature sensor) 35a provided on the heat retaining wall 32 '. This infrared non-contact sensor 35a is difficult to use in a high-temperature environment, and the non-contact sensor 35a in FIG. 4 is an example installed outside the heat insulating wall 32 '. The cylindrical rotating body 1 passes through the infrared passage hole 35'. Measure the surface temperature. Further, the non-contact sensor 35b is an example installed below the partition plate 33 inside the heat insulating wall 32 '. The temperature of the non-contact sensors 35a and 35b can be controlled on the upstream side and the downstream side of the high-frequency heating unit 5 in the rotational direction. The non-contact sensors 35a and 35b may use a laser type.

  Three non-contact sensors 35a or 35b are provided for each of the plurality of high-frequency heating units 5a, 5b, and 5c, and the heat insulation sheet 34 is provided at sensor measurement points 36 (three places) for measuring the surface temperature of the cylindrical rotating body 1. It is configured so as to cut out. That is, the heat insulating sheet 34 is composed of four sheets 34a, 34b, 34d, and 34e provided with three gaps at the sensor measurement points. The surface position of the high-frequency heating unit 5 corresponding to the gap at the position of the sensor measurement point 36 has a large amount of heat transfer from the cylindrical rotating body 1 so as to suppress the temperature rise of the surface. Affix to.

  In the case of gypsum, in the high-frequency heating units 5a and 5b on the supply side, the amount of heat that the dihydrate gypsum is β-hemihydrated at about 150 ° C. is large and the temperature rise of the gypsum can be suppressed. It is also possible to control the output of the high-frequency heating units 5a and 5b with one non-contact sensor 35a.

  As shown in FIG. 5, a plurality of lifting portions (gypsum stirring blades) 4 are provided at equal intervals on the inner surface of the cylindrical rotating body 1 (12 in FIG. 5). In the following description, as shown in FIG. 5, the inside of the cylindrical rotating body 1 is viewed from the supply side A, and the right hand side with respect to the high-frequency heating unit 5 is the upstream side R1 in the rotational direction and the high-frequency heating unit 5. The left hand side is referred to as the downstream side R2 in the rotational direction.

  The lifting portion 4 is formed by bending one long plate into a substantially L-shaped cross section (see FIG. 7), and the long plate is in one direction at the predetermined position (the same direction as the rotation direction). Are joined to the inner surface of the rotating body 1 to form a joining plate portion 4 ′ and a substrate portion 4 ″ that forms an obtuse angle with the joining plate portion 4 ′. By bending in the same direction, a protruding plate portion 4a having an obtuse angle with the substrate portion 4 ″ is formed. As a result, the entire plate is processed and formed into a substantially L-shaped cross section. The edge 4b of the joining plate portion 4 ′ is welded to the inner surface of the rotating body 1. The mounting angle of the lifting portion 4 to the inner wall of the rotating body 1 is such that the protruding plate portion 4a rotates in the direction m. And the substrate portion 4 ″ is positioned so as to be perpendicular to the vertical line. The edge 4b of the joint plate portion 4 'for circumferential welding on the rotating body 1 inner wall. Therefore, in the mounted state, the mounting angle of the bonding plate portion 4 ′ with respect to the inner wall of the rotating body 1 is a position retracted in the counter-rotating direction by an angle θ 1 with respect to the vertical line. Providing the angle θ1 in this way has the effect of increasing the amount of gypsum lifted in the lifting portion 4.

  Further, in order to increase the lifting amount of gypsum, the protruding plate portion 4a is extended to the edge of the substrate portion 4 ″. That is, the protruding plate portion 4a is formed at an angle θ2 that is open from a right angle with respect to the substrate portion 4 ″. And the lifting part 4 has a cup-shaped (substantially L-shaped) cross-sectional shape. The angle θ2 is an angle with respect to a vertical line orthogonal to the substrate portion 4 ″. As described above, the joining plate portion 4 ′, the substrate portion 4 ″, and the protruding plate portion 4a are integrally manufactured by bending the plate. Alternatively, the radius of curvature of the bent portion may be increased.

  In the lifting portion 4 in the vicinity of the lower downstream portion of the cylindrical rotating body 1 (range from the lowest part of the cylindrical rotating body 1 to the rotational direction 1/8 circle), the laminated thickness of the plaster is large, and the protruding plate portion 4a is Since the water vapor generated in the rotating body 1 is covered (see the lifting portion 4 at the position K in FIG. 4), the end of the lifting portion 4 on the supply side of the rotating body 1 and the discharge of the rotating body 1 are the same. The structure is such that water vapor escapes from the ends of the lifting portion 4 on the side, that is, both ends of the lifting portion 4 (see arrow d in FIG. 1), that is, both end portions of the lifting portion 4 and the left and right closed wall surfaces of the cylindrical rotating body 1 A space is provided between them to allow the water vapor to escape, and further, small holes 38 of about several millimeters are provided in the substrate portion 4 ″ of the lifting portion 4 at intervals of several tens of cm, for example, so that the longitudinal length of the lifting portion 4 is If it is long, water vapor can easily escape from the small hole 38. The small hole 38 has the same effect even in a slit such as a long hole, etc. Further, as shown in FIG. It is also conceivable that each divided row 4c is shifted in the circumferential direction and attached in a zigzag arrangement as a whole.

  As an operation method of heating and dehydrating dihydrate gypsum by high-frequency heating, a target temperature of a temperature controller (not shown) that controls output with a measured temperature from the non-contact sensor 35a or 35b is set for each of the plurality of high-frequency heating units 5. Set to a predetermined temperature. When producing β hemihydrate gypsum, the surface temperature of the cylindrical rotating body 1 in contact with gypsum is set to a temperature that does not produce type 2 anhydrous gypsum, and when treating gypsum board, it depends on the use of β hemihydrate gypsum. If carbonization of paper is a problem, set it below the carbonization temperature.

  When the operation is started, the rotary drive motor 3 is rotated to start the rotation of the cylindrical rotating body 1, the high-frequency heating unit 5 is energized, and the cylindrical rotating body 1 is induction-heated. After a certain time or when the temperature of the measuring point 36 corresponding to the high-frequency heating unit 5a on the supply side A approaches the target temperature, the screw conveyor 9 of the supply device 12 is driven by the motor 10, and the rotation of the conveyor 9 causes the cylinder to rotate. Supply of gypsum into the body 1 is started.

  When the cylindrical rotating body 1 rotates in the direction of the arrow m, the plaster is rubbed by the inner surface side of the joining plate portion 4 ′ of the lower lifting portion 4 (position k1 in FIG. 5), and the lifting portions at the positions k2 and k3. In the state where gypsum has entered the entire inner area of 4, the gypsum is lifted upward. Water vapor is discharged from the small hole 38 at the position k2. As it further rotates, it begins to fall downward so that the gypsum gradually overflows at the positions after the positions k4 and k5, and it is efficient by dropping the gypsum from the position k7 to the position k10 on the upstream side R1 in the rotation direction. The gypsum can be stirred.

  When the discharge amount of the heated dehydrated gypsum from the cylindrical rotating body 1 becomes constant, the discharge-side high-frequency heating unit 5c (when there are three high-frequency heating units 5) is not operating 100% (high frequency It is determined that there is a surplus heating power (according to a signal from the inverter or the like), and the inverter frequency of the motor 10 is increased in order to increase the supply amount of dihydrate gypsum. However, the high-frequency heating unit 5c on the discharge side has a stable quality of heat dehydration with a margin of several percent with respect to the maximum output in order to cope with fluctuations in the heat load due to the moisture content of the supplied dihydrate gypsum. It is also possible to discharge gypsum.

  The water content (free water) of dihydrate gypsum can be confirmed before supply, and the supply amount can be set. In particular, when the water content is 2% or more, the supply amount is adjusted by checking automatically or manually before supply. The residence time of the gypsum is adjusted by the rotation speed and the inclination angle of the cylindrical rotating body 1, and when discharging the β hemihydrate gypsum, for example, the residence time is 8 minutes to 40 minutes depending on the particle size variation and the repose angle. Adjust within minutes.

  A moisture meter is attached to the discharge device 18, a small amount (about 20g or less) of the heated dehydrated gypsum is sampled, heated with a heater, and the weight change up to the anhydrous gypsum is measured. If the weight is reduced, it is β hemihydrate gypsum.If the weight is reduced further, dihydrate gypsum is mixed. If there is no, it is judged that it is almost anhydrous gypsum.

  When it is desired to produce β hemihydrate gypsum, if dihydrate gypsum is mixed, heat dehydration is judged to be insufficient, and control to maximize the output of the high-frequency heating unit 5 and the amount of dihydrate gypsum supplied are set. It is also conceivable that control is performed to reduce the number of revolutions of the cylindrical rotating body 1 and extend the residence time of the gypsum in the cylindrical rotating body 1. Moreover, when 3 type | mold anhydrous gypsum is mixed, it will be judged that there exists heat dehydration surplus and the control which increases the supply amount of dihydrate gypsum is performed.

  When it is desired to produce type 2 anhydrous gypsum, the temperature of the heated dehydrated gypsum discharged from the cylindrical rotating body 1 is measured with a temperature sensor to control the amount of gypsum supplied and control the temperature of the high-frequency heating unit 5 and the like. Do.

  When the rotation of the screw 9 of the supply device 12 is stopped at the end of the operation, the supply of dihydrate gypsum into the cylindrical rotating body 1 stops and the heating load of the high-frequency heating unit 5 starts to decrease. Control for lowering the output from the high-frequency heating unit 5a on the supply side within the time T with respect to the residence time T in the cylindrical rotating body 1 during steady operation, and the high-frequency heating unit 5 are all stopped within the T time to be cylindrical The control etc. which continue heating dehydration by the preheating of the rotary body 1 can be considered.

  In the gypsum supply amount control, the rotational speed control of the cylindrical rotating body 1, the heating control of the high-frequency heating unit 5, and the control at the start and end of the operation of the apparatus, the sequencer, inverter and temperature controller should have a learning function. Is also possible.

  When forced exhaust is performed by the exhaust fan 15 or forced supply is performed by the air supply fan of the air supply port 23, the temperature in the cylindrical rotating body 1 and the product temperature of the heated dehydrated gypsum discharged from the main body discharge port 17 are measured. It is also possible to perform air volume control that reduces the air volume of the fan in order to suppress heat loss at the start of the operation or changes in the outside air temperature.

  The temperature sensor TS is mounted in the cylindrical rotating body 1 from the fixed end at a position where it does not interfere with the lifting portion 4 between the center and the discharge side in the longitudinal direction of the cylindrical rotating body 1 (see FIG. 1), and hemihydrate gypsum is attached. If it is desired to obtain the temperature, the temperature of the cylindrical rotating body 1 varies depending on the mounting height, but if it is 170 ° C. or higher, it is judged that anhydrous gypsum is mixed, and control to increase the amount of gypsum supplied or high-frequency heating output If the temperature of the cylindrical rotating body 1 is 130 ° C. or less, it is determined that dihydrate gypsum is included, and control for decreasing the amount of gypsum supplied or control for increasing the high-frequency heating output is performed. In addition, the supply amount depending on the internal temperature and the high frequency heating output are also effective.

  The exhaust passage for the water vapor generated in the cylindrical rotating body 1 is the outer passage 12a, the inside of the hollow pipe 9a, the hose 13a, and the exhaust pipes 24 'and 24' 'in FIG. An elbow joint and nozzle are provided inside, and piping is provided outside the passage connected to it, and the compressed air pressurized by the air compressor is passed through an on-off valve and check valve (a directional valve that flows only from the outside to the inside). When gypsum particles contained in the exhaust of water vapor accumulate in the passage, air blows off the gypsum deposit at the start or end of operation of the equipment. The outer flow path 12a and the like in the supply device 12 may be washed with water instead of air.

  As shown in FIG. 6, inclined plates 39 (three in FIG. 6) can be provided inside the cylindrical rotating body 1. The inclined plate 39 is fixed with a downward inclination from the rotation direction downstream side R2 of the rotating body 1 to the rotation direction upstream side R1. The gypsum dropped from the lifting portion 4 at the upper position of the cylindrical rotating body 1 moves along the slope on the upper surface of the inclined plate 39 and falls to the upstream side R1 in the rotation direction of the high-frequency heating portion 5. The inclined plate 39 is plate-shaped, and is disposed in the longitudinal direction of the cylindrical rotating body 1, and both ends are fixed to both side surfaces of the rotating body 1. As shown in FIG. 6, a plurality of inclined plates 39 can be provided. In the case of a plurality of inclined plates 39, a gap 40 is provided between the inclined plates 39 for the water vapor passage so that the gypsum does not fall from the gaps 40. A configuration with overlapping directions. Further, the inclined plate 39 can also heat the gypsum with a built-in heater H. Furthermore, it is also possible to heat the gypsum by using a square pipe for the inclined plate 39 and flowing a high-temperature gas therein.

  FIG. 8 shows another embodiment for purifying and exhausting water vapor exhausted from the rotating body 1. As shown in the figure, the water vapor generated from the cylindrical rotating body 1 passes through the exhaust pipes 24 ′ and 24 ″ from the steam passage 42 at the upper part of the terminal fixing lid 16 or the upper surface of the tip of the screw 9 ′ on the supply side. And flows into the heat exchanger tank 43. Water in the tank 43 is circulated by the shower pump 44, sprayed from the nozzle 45, and comes into contact with water vapor from the exhaust pipes 24 ′ and 24 ″. A scattering prevention plate 46 is attached to the inlet of the heat exchange tank 43 so that the spray water does not enter the exhaust pipes 24 ', 24 ". Water vapor and air that has not been condensed into water by the spray water passes through the exhaust passage 47 and is exhausted. A drain wall 49 of punching metal or the like is provided in the exhaust passage 47 so that the exhaust water is exhausted from the exhaust port 48 and spray water does not scatter from the exhaust port 48.

  Since it is an exhaust of water vapor containing gypsum fine particles generated by heat dehydration of dihydrate gypsum, most of the gypsum fine particles become water-soluble and precipitate when sprayed with water. The precipitated gypsum is periodically removed by discharging or scooping up the drain valve 50 when the shower pump 44 is stopped.

  A heat exchanger 51 is immersed in the heat exchange tank (heat exchanging means) 43, and a heat medium of water or antifreeze is passed through the heat exchanger 51 by a circulation pump 52. The heat exchanger 51, the heat exchanger 53 and the screw outer cylinder 9 ″ flow in the order of the circulation pump 52 and the circulation tank 54. The heat medium flows in the outer passage 12a (discharge pipe) and the inner passage 12b (supply pipe) in the heat exchanger 53 of the supply device 12. ) And heat exchange through the heat transfer surface (screw outer cylinder 9 ″, etc.) to raise the temperature of the dihydrate gypsum, the temperature of the heat medium is lowered, and water vapor is held in the heat exchange tank 43. The temperature rises with the heat. The heat medium may be piped around or inside the supply hopper 6 'to raise the temperature of the dihydrate gypsum. It is also conceivable to circulate the water in the heat exchange tank 43 directly. The tanks 43 and 54 can be supplied with tap water or the like from a water supply pipe 55 and can be automatically supplied with a ball tap 56. The valve 57 is an open / close valve for cleaning the tank. The tanks 54 and 43 are provided with overflow pipes 58 and 58 'so that water does not overflow. An opening 59 for ventilation is provided in the upper part of the circulation tank 54.

  When the amount of heat recovered from the water vapor in the heat exchange tank 43 by the heat medium is larger than the amount of heat released from the heat exchanger 53, the heat exchange tank 43 is set by the cooling fan 60 in order to reduce the amount of water vapor from the exhaust port 48. Air cooling is also conceivable. It is also conceivable that the temperature of the water in the heat exchange tank 43 is raised by the heater 47 'at the start of operation. The exhaust pipe 24 'in the vicinity of the end of the rotating body 1, the steam passage 42 in the vicinity of the starting end of the rotating body 1, the outer passage 12a, and the like constitute exhaust means.

  FIG. 9 shows an embodiment in which burner heating is used together. A burner combustion part is attached to the outside of the fixed end on the end face side of the cylindrical rotating body 1, and a burner radiation cylinder is fixed in the cylindrical rotating body 1 from the fixed end. Mounting, hot air from the burner flows through the burner radiant cylinder to indirectly heat the gypsum, and the combustion gas is exhausted by exchanging heat with gypsum in the supply device, and the burner heating is used to heat the gypsum on the supply side of the cylindrical rotating body It is. As shown in the figure, a starting end fixing lid 61 is fixed to a gypsum supply side of a rotating cylindrical rotating body 1 through a seal 62 for preventing water vapor from leaking, and a supply device 63 is fixed to the starting end fixing lid 61. Then, dihydrate gypsum is supplied into the cylindrical rotating body 1 from the hopper 6 ″ by the rotary screw conveyor 9. Hot air is generated in the burner (burner combustion section) 64 using fossil fuel as fuel, and the hot air is sent to the hot air pipe 65. The hot air header 66 passes through the hot air pipe return 67 such as a multi-pipe and flows into the hot air return header 68 and is exhausted from the hot air exhaust port 69. Here, the burner hot air outlet pipe 65, the hot air header 66, and the hot air pipe return 67 are discharged. Etc. to form a burner radiating cylinder.

  The hot air passage is fixed without rotating, and the hot air return header 68 and the hot air duct 65 are fixed to the start end fixing lid 61 while maintaining airtightness.

  The combustion gas exhausted from the hot air exhaust port 69 can be exhausted from the exhaust port 72 after exchanging heat with the gypsum in the supply device 63 from the heat exchange port 70 through the exhaust gas heat exchanger 71.

  The hot air generated by the burner 64 may be exhausted from the terminal fixing lid 16 without being folded by the hot air header 66. If comprised in this way, the high temperature hot air of a burner heating will be used for the heating of the gypsum of a supply side, and a burner heating will be cylindrical by exhausting the hot air which carried out temperature fall (in the case of (beta) semi-water gypsum 150 degreeC or more) from a discharge side There is an effect similar to that used for heating the gypsum on the supply side from the discharge side of the rotating body.

  In FIG. 10, water vapor containing gypsum dust is introduced into the dust collecting portion 73 through the exhaust pipe 24 a from the upper part of the terminal fixing plate 16, gypsum dust is collected by the filter cloth 74, and only the water vapor is screwed by the fan 75. It introduce | transduces into the screw outer cylinder (outer channel | path 12a) of the heat exchanger 53 in a supply part, and is set as the structure exhausted from exhaust port 12a '. Also in this case, the water vapor exchanges heat with the gypsum through the heat transfer surface (screw outer cylinder (outer passage 12a)) to raise the temperature of the dihydrate gypsum. The compressed air in the compressed air tank 77 is pulsated at intervals of several tens of seconds (less than 1 second), opens the electromagnetic valve 78, passes through the compressed air piping 79, and is injected into the filter cloth 74 from the nozzle 80. The gypsum dust collected on the outside is shaken off at the bottom of the dust collecting portion 73. The gypsum dust accumulated at the bottom of the dust collecting unit 73 is periodically taken out from the dust discharge port 81 or continuously taken out with a screw or the like.

  8 to 10 can be provided with a heat exchange mechanism including the discharge device 18, the discharge screw conveyor 19, the air supply port 23, the motor 20 and the like shown in FIG. Further, an exhaust means is constituted by the exhaust pipe 24a near the end of the rotating body 1, the outer passage 12a near the starting end of the rotating body 1, and the like.

  As described above, according to the present invention, the dihydrate gypsum is efficiently mixed by the plurality of high-frequency heating units 5 attached to the lower side of the cylindrical rotating body 1 and the dihydrate gypsum is not mixed by temperature control. Hemihydrate gypsum or anhydrous gypsum can be obtained.

  Further, it is possible to save energy by using water vapor generated by heat dehydration of gypsum and using exhaust heat from the heat dehydrated gypsum discharged and reducing the amount of heat radiation.

  In addition, a gypsum heating device having a simple device configuration can be provided.

  In addition, the high-frequency heating from the outside of the cylindrical rotating body 1 and the heating by the burner combustion heat from the inside of the cylindrical rotating body 1 are used in combination, and the characteristics of the high-frequency heating that allows easy temperature control and quick rise in temperature at start-up It is possible to realize a heating apparatus with high thermal efficiency that combines the features of burner heating with low fuel costs.

  Further, by separating the high-frequency heating unit at the lower part of the rotating body 1 and the outer upper part of the rotating drum by a partition plate, the amount of heat released by the convection of the air at the upper and lower parts of the rotating body 1 can be reduced, and The amount of heat released to can be reduced.

  In addition, since dihydrate gypsum is semi-hydrated by removing crystal water at about 150 ° C., heating per unit length in the longitudinal direction can be achieved by arranging a plurality of high-frequency heating units in the longitudinal direction of the cylindrical rotating body. Quantity output control can be performed.

It is side surface sectional drawing of the heating apparatus of the waste gypsum based on this invention. It is a cross-sectional view of the cylindrical rotating body of the same apparatus. (A) is sectional drawing of the high frequency heating part of an apparatus same as the above, (b) is a perspective view of a high frequency heating part same as the above. (A) is a side view of the cylindrical rotating body of the same apparatus, (b) is a cross-sectional view of the rotating body of the same apparatus. It is a cross-sectional view of the cylindrical rotating body of the same apparatus. It is a cross-sectional view of other embodiment of the cylindrical rotary body of an apparatus same as the above. (A) is a front view of the lifting part of the same apparatus, (b) is a side view of the lifting part, (c) is a sectional view of a cylindrical rotating body in which the lifting parts are divided and staggered. It is side surface sectional drawing which shows other embodiment of an apparatus same as the above. It is side surface sectional drawing which shows other embodiment of an apparatus same as the above. It is side surface sectional drawing which shows other embodiment of an apparatus same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylindrical rotary body 4 Lifting part 4 'Joining board part 4 "Board | substrate part 4a Projection board part 5 High frequency heating part 5a-5c High frequency heating part 6 Supply hopper 9 Screw conveyor 12 Supply apparatus 12a Outer channel | path 12b Inner channel | path 15 Supply air fan 17 Discharge port 18 Discharge device 19 Screw conveyor 31 Heat insulation casing 33 Partition plates 34a to 34d Thermal insulation sheets 35a and 35b made of ceramic fiber Infrared type non-contact temperature sensor 39 Inclined plate 64 Burner 73 Dust collector

Claims (12)

In the waste gypsum heating device that heats crushed waste gypsum,
A screw-type supply unit for conveying the waste gypsum supplied from the supply hopper;
A cylindrical rotating body that receives the supply of the waste gypsum from the screw-type supply unit and is rotationally driven by a driving means in a state of being installed at an inclination,
A high-frequency heating unit installed in the vicinity of the outer peripheral surface of the rotating body outside the cylindrical rotating body;
A discharge part for discharging β hemihydrate gypsum or anhydrous gypsum from the end of the cylindrical rotating body;
A heating device for waste gypsum comprising exhaust means for exhausting water vapor generated in the cylindrical rotating body,
The high-frequency heating unit is divided into a plurality of positions at a position facing the lower outer peripheral surface of the rotating body,
A plurality of gypsum stirring blades having a substantially L-shaped cross section are provided on the inner wall surface of the cylindrical rotating body, and the gypsum lifted above the rotating body by the stirring blades as the rotating body rotates is rotated at the lower part of the rotating body. A device for heating waste gypsum, characterized in that it can fall to the upstream side in the direction.   The screw-type supply unit discharges the waste gypsum from the supply hopper into the cylindrical rotating body, and discharges water vapor generated in the rotating body in a direction opposite to the gypsum conveying direction. The waste gypsum according to claim 1, wherein the waste pipe is configured to be capable of heat exchange between the supply pipe and the discharge pipe via a heat transfer surface. Heating device.   Heat exchange means for heating the heat medium using the heat of water vapor exhausted from the exhaust means is provided, and the screw-type supply unit includes a screw for conveying waste gypsum from the supply hopper into the cylindrical rotating body. Provided with a supply pipe and a discharge pipe for discharging the heat medium in a direction opposite to the transport direction of the gypsum, and further, the supply pipe and the discharge pipe exchange heat through a heat transfer surface. The apparatus for heating waste gypsum according to claim 1, wherein the heating apparatus is configured to be obtained.   A dust collecting part for collecting gypsum dust in water vapor exhausted from the exhaust means is provided, and the screw type supply part is provided with a screw for conveying waste gypsum from the supply hopper into the cylindrical rotating body. A discharge pipe that discharges water vapor that has passed through the dust collecting section in a direction opposite to the direction of transfer of the gypsum, and the supply pipe and the discharge pipe are heated via a heat transfer surface. 2. The waste gypsum heating device according to claim 1, wherein the heating device is configured to be exchangeable. While providing a fan for supplying outside air to the cylindrical rotating body,
A heat exchanging mechanism for cooling the gypsum after heat dehydration with the above air supply and heating the air supply with the gypsum after heat dehydration is provided at the discharge part of the gypsum after heat dehydration in the cylindrical rotating body. The apparatus for heating waste gypsum according to claim 1, wherein: A non-contact type temperature sensor that can measure the temperature of the outer peripheral surface position on the upstream side in the rotational direction or the downstream side in the rotational direction of the cylindrical rotating body is provided for each of the high-frequency heating units,
The configuration is such that the output of the high-frequency heating unit and the gypsum supply amount by the screw-type supply unit can be controlled based on the outer peripheral surface temperature of the rotating body measured by the temperature sensor. The waste gypsum heating device according to any one of 1 to 5. The plaster agitating blade is composed of a joining plate portion and a substrate portion that form a substantially L-shaped cross section, and has a predetermined angle in the direction of the joining plate portion with respect to the substrate portion at the edge of the substrate portion. And has a protruding plate part protruding from
The waste gypsum heating device according to any one of claims 1 to 6, wherein a space is provided between both end portions of the gypsum stirring blade and the left and right closed wall surfaces of the cylindrical rotating body. . The cylindrical rotating body and the high-frequency heating unit are configured to be covered with a heat insulating casing,
A partition plate is provided near the upper portion of the high-frequency heating unit inside the heat insulation housing, and the internal space of the heat insulation housing is divided into an installation space for the high-frequency heating unit and a space on the cylindrical rotating body side. The heating apparatus for waste gypsum according to claim 1, wherein the heating apparatus is a waste gypsum.   A ceramic fiber heat insulating sheet having a thickness of 9 mm or less is wrapped around and fixed to the outside of the cylindrical rotating body with a heat-resistant tape or a heat-resistant adhesive, and includes measurement points of a non-contact temperature sensor on the outer periphery of the rotating body in the sheet. The apparatus for heating waste gypsum according to any one of claims 1 to 8, wherein a portion is cut out.   The axial length of the cylindrical rotating body of each high-frequency heating coil of the plurality of high-frequency heating units is configured such that the discharge side coil is longer than the supply side coil of the cylindrical rotating body. The heating apparatus for waste gypsum according to claim 1, wherein the heating apparatus is a waste gypsum.   An inclined plate is provided inside the cylindrical rotating body, and the gypsum dropped from the gypsum stirring blade is moved on the upper surface of the inclined plate and dropped to the upstream side in the rotation direction from the installation position of the high-frequency heating unit. The waste gypsum heating apparatus according to any one of claims 1 to 10. A burner combustion part is attached outside the fixed end of the cylindrical rotating body, and a burner radiator is fixed and attached to the cylindrical rotor from the fixed end, and hot air from the burner is passed through the burner radiator to indirectly heat the gypsum. 2. The waste gypsum heating apparatus according to claim 1, wherein combustion gas is exchanged with gypsum in the supply apparatus and exhausted, and burner heating is used to heat the gypsum on the supply side of the cylindrical rotating body.

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