JP6618080B2 - Adherent removal method for band dryer and band dryer - Google Patents

Description

  The present invention has a moisture content and a highly dehydrated sludge formed in a desired shape by a molding machine (water content is about 80% (humidity standard)), air permeability that orbits viscous materials such as livestock dung and food residues. It is supplied onto an endless conveyor belt with air flow, and hot air of about 200 ° C. is blown in the other direction from above or below to the viscous material such as dehydrated sludge on the conveyor belt from above or below, and the dehydrated sludge on the conveyor belt In a band dryer that dries the viscous material such as dehydrated sludge to about 70% of the self-flammability limit (wet standard), the dehydrated sludge and other viscous material adhered to the conveyor belt during the drying treatment of dehydrated sludge and other viscous materials The present invention relates to a band-type dryer deposit removing method and a band-type dryer that can be reliably and easily removed.

  In general, when effective use or commercialization of viscous materials such as sewage sludge (dehydrated sludge), livestock dung, food residues, etc., the moisture content of the viscous material is high, and thus the viscous material is dried.

  For example, when the viscous material is sewage sludge (dehydrated sludge), as shown in FIG. 2, the sewage sludge (dehydrated sludge) is dried using a band dryer, and the dried sludge is used as a solid fuel. Alternatively, it is used as a raw material for aggregates.

  As shown in FIG. 2, the band-type dryer 30 includes a conveyor 32 that transports the formed sludge 31b formed from the dewatered sludge 31a in the horizontal direction, a casing 33 that surrounds a portion of the conveyor 32 and forms a drying chamber, and a dehydrator. The sludge 31a is formed into a desired shape to form a formed sludge 31b. The molding machine 34 that supplies the formed sludge 31b onto the conveyor 32 and the drying air supplied into the drying chamber of the casing 33 are heated to about 200 ° C. The warm air 35 is provided with warm air supply means 36 for blowing the warm air 35 onto the formed sludge 31b on the conveyor 32.

  The conveyor 32 rotationally drives the drive sprocket 32a and the driven sprocket 32b, a transport belt 32c formed of a breathable endless wire conveyor belt wound around the sprockets 32a and 32b, and the drive sprocket 32a. A drive motor (not shown) is provided, and hot air 35 is caused to flow around the formed sludge 31b on the conveyor belt 32c through the mesh and through holes of the conveyor belt 32c.

  Further, the hot air supply means 36 uses a heat 37 such as sludge incineration exhaust heat (combustion exhaust gas) to heat the drying air to a hot air 35 of about 200 ° C., and a heat exchange. A drying air circulation path 39 that circulates the drying air (hot air 35) heated by the vessel 38 between the casing 33 and the heat exchanger 38, and a circulation fan 40 that is interposed in the drying air circulation path 39. And a condenser 41 that is interposed in the drying air circulation path 39 and dehumidifies moisture contained in the drying air (hot air 35), and is disposed below the conveyor belt 32c above the conveyor 32. A plurality of hot air outlets 42 for blowing the hot air 35 to the formed sludge 31b on the conveyor belt 32c are provided, and drying air (hot air 35) is circulated in order to reduce the amount of heating heat. .

  In FIG. 2, 33a is an air outlet formed in the casing 33, 33b is an outlet formed in the casing 33, 34a is a high-pressure container of the molding machine 34, 34b is a charging hopper of the molding machine 34, and 34c is a molding machine 34. A screw shaft with a screw blade, 34d is a motor of the molding machine 34, 34e is a die of the molding machine 34, and 43 is a scraper that wipes off the dried sludge 31c.

  Thus, according to the band-type dryer 30, the dewatered sludge 31a having a water content of about 80% (based on the moisture amount) is formed by the molding machine 34 to be transported as a plurality of rod-shaped molded sludges 31b. Contact with hot air 35 (drying air of about 200 ° C.) supplied on the belt 32c and blown upward from the hot air outlet 42 while being conveyed through the casing 33 (drying chamber) by the conveyor belt 32. Thus, dried sludge 31c having a moisture content of about 70% (humidity standard) is discharged from the outlet 33b of the casing 33.

  By the way, since the dry sludge 31c having a moisture content of about 70% (humidity standard) has a relatively strong adhesion, even if the conveyor belt 32c passes the turning point, it does not adhere to the surface of the conveyor belt 32c and peel off. There is. When the dried sludge 31c comes around without being peeled off from the conveying belt 32c, the formed sludge 31b is placed on the dried sludge 31c, and drying becomes inefficient.

  Therefore, as a method of detaching the dried sludge 31c attached to the conveyor belt 32c from the conveyor belt 32c, a scraper 43 is provided at a folded portion of the conveyor belt 32c, and the dried sludge 31c attached to the conveyor belt 32c is wiped off by the scraper 43. In this case, a part of the dried sludge 31c is crushed by the scraper 43, and the mesh of the conveyor belt 32c may be filled with the dried sludge 31c to cause clogging.

  As another method, the temperature of the hot air 35 is increased or the air volume is increased, or the conveying belt 32c is dried so that the dried sludge 31c is sufficiently dried at the turning point of the conveying belt 32c by its own weight. There is also a method of increasing the residence time by increasing the length of this, but also in this case, the energy consumption required for drying and the installation area of the dryer are increased.

  In view of this, band dryers described in Japanese Patent No. 5768690 (Patent Document 1) and Japanese Patent No. 5443205 (Patent Document 2) have been developed as band-type dryers that solve the above-described problems.

  That is, the former band-type dryer has a plurality of conveyor belts arranged in the vertical direction, and the first and second conveyor belts are rotated in the same direction from the top. The dried sludge does not peel off due to its own weight at the turning point of the conveyor belt, it is further conveyed with the turning point of the first-stage conveyor belt attached to the belt surface, and when drying progresses to the extent that it is peeled off due to the dead weight of the dried sludge, Then, it is moved to the second stage conveyor belt. In addition, the band type dryer is provided with a scraper that forcibly removes the dried sludge that has not been dried to the extent that it falls by its own weight from the first stage conveyor belt. This band type dryer can produce dry sludge with stable quality without increasing the volume of warm air or increasing the temperature.

  On the other hand, in the latter band type dryer, a hot air blowing nozzle is arranged at an upstream upper position of the first stage conveyor belt, and before the sludge formed by the forming nozzle is placed on the conveyor belt, the nozzle Then, the surface of the sludge is dried by blowing hot air at 170 ° C. to 240 ° C. to reduce the adhesion force of the sludge to the conveyor belt so that it can be easily detached from the conveyor belt. Since this band type dryer can shorten the residence time of the formed sludge on the first stage conveyor belt, the length of the conveyor belt can be shortened and the installation area can be reduced, The throughput of the dryer can be increased.

  However, in the band-type dryer described above, as a means for lowering the moisture content of sludge and separating it at the turning point of the first-stage conveyor belt, the conveyor belt is arranged in multiple stages to increase the sludge residence time. There is a need.

  Further, if the moisture content of the sludge is high at the turning point of the first stage conveyor belt, it becomes impossible to remove the sludge that has entered the mesh of the conveyor belt with a scraper.

  Furthermore, if the stacking height of the molded sludge on the conveyor belt is increased, it may get into the mesh of the conveyor belt. If the countermeasures against clogging of the conveyor belt are not completely taken, the molded sludge is further formed on the molded sludge. It can not be said that increasing the processing efficiency by loading.

  In addition, if the surface of the formed sludge is dried too much, moisture inside the sludge is difficult to escape and there is a problem that the drying efficiency is lowered.

Japanese Patent No. 5768690 Japanese Patent No. 5443205

  The present invention has been made in view of such problems, and its purpose is to reliably and easily remove the debris such as dewatered sludge adhered to the conveyor belt during the drying treatment of the dehydrated sludge and other viscous materials. An object of the present invention is to provide a band-type dryer and a band-type dryer for removing deposits.

In order to achieve the above object, the method for removing deposits of a band-type dryer according to the present invention supplies a viscous material formed by a molding machine onto a breathable endless conveying belt that moves around, and the conveying belt. In the band type dryer in which hot air is blown to the upper viscous material from the warm air supply means in the other direction from above or below to dry the viscous material on the conveyor belt, the belt surface after the conveyor belt is folded back The adhering viscous material is detected by the detecting means, and a part of the hot air branched from the hot air supplying means is heated by the hot air supplying means based on the detection signal from the detecting means to ignite and burn the viscous material or gas. and hot air for reduction, the hot air is blown to the viscous substance adhering to the belt surface after wrapping of the conveyor belt viscous product ignited combustion or gasification and carbides, carbide scouring hand this carbide It is characterized by the rubbing take as to the thing in.

  The hot air is preferably used for drying the viscous material at the initial stage of molding on the conveyor belt after spraying the viscous material adhering to the belt surface of the conveyor belt.

The band-type dryer according to the present invention supplies the viscous material formed by the molding machine onto an air-permeable endless conveying belt that moves around, and warm air is supplied from the hot air supply means to the viscous material on the conveying belt. In a band-type dryer in which the viscous material on the conveyor belt is blown in the other direction from above or below, the detecting means for detecting the viscous material adhering to the belt surface after the conveyor belt is turned back; Hot air is supplied based on the detection signal from the detection means, and the hot air is blown onto the viscous material adhering to the belt surface of the conveyor belt to ignite, burn, or gasify the viscous material to form carbide, and And a carbide scraping means for scraping the carbide adhering to the conveyor belt, the hot air supply means includes a branch path for branching a part of the hot air from the hot air supply means, and hot air in the branch path The It detects the temperature of the hot air sent from the electric heater to the hot air outlet, and the hot air outlet that blows the hot air from the branch path to the viscous material adhering to the belt surface of the conveyor belt. A temperature controller for controlling the electric heater so that the temperature of the hot air becomes a temperature at which the viscous material is ignited, burned or gasified, and the hot air outlet is positioned below the viscous material at the initial stage of molding on the conveyor belt. In addition, it is characterized in that it is disposed at a position facing the belt surface after the conveyor belt is folded back .

  The carbide scraping means includes a roll wire brush that rotates in a direction opposite to the rotation direction of the transport belt at a position near the belt surface of the transport belt, and scrapes the carbide adhering to the transport belt by rubbing the belt surface. Preferably it is.

  The method for removing deposits from a band-type dryer according to the present invention detects viscous materials adhering to a conveyor belt, blows hot air on the detected viscous materials, and ignites, burns, or gasifies the viscous materials to burn and brittle carbides. Since the carbide is scraped off, the viscous material adhering to the conveyor belt can be reliably and easily removed.

  In addition, the method for removing deposits of the band dryer according to the present invention uses hot air after spraying on the viscous material adhering to the belt surface of the conveyor belt to dry the viscous material at the initial stage of molding on the conveyor belt. Therefore, heat energy can be used effectively. In this case, since the viscous material in the initial stage of molding has a high water content, the viscous material can be dried well without being ignited and combusted by hot air or gasified in a short time.

  Furthermore, in the method for removing deposits of the band type dryer according to the present invention, it is necessary to input extra energy to produce hot air, but the hot air is also used to dry the viscous material at the initial stage of molding on the conveyor belt. Therefore, it is possible to reduce the flow rate of the hot air blown to the viscous material on the conveyor belt.

  The band type dryer according to the present invention detects a viscous material adhering to the belt surface after the conveyance belt is turned back, supplies hot air based on a detection signal from the detection means, and conveys the hot air. Because it has hot air supply means that blows on the viscous material adhering to the belt to ignite, burn, or gasify the viscous material to form carbide, and carbide scraping means that scrapes the carbide adhering to the conveyor belt The viscous material adhering to the conveyor belt can be reliably and easily removed.

  In the band type dryer according to the present invention, the hot air supply means heats a part of the hot air to generate hot air, and hot air that blows the hot air on the viscous material adhering to the belt surface of the conveyor belt. And a temperature controller for detecting the temperature of the hot air sent from the electric heater to the hot air outlet and controlling the electric heater so that the temperature of the hot air is about 300 ° C. Since it is disposed at a position below the viscous material at the initial stage of molding on the conveyor belt and at a position facing the belt surface after the conveyor belt is folded back, it is possible to effectively use heat energy and on the conveyor belt. It is possible to reduce the flow rate of hot air blown to the viscous material.

  Further, in the band type dryer according to the present invention, the carbide scraping means rotates to a position near the belt surface of the conveyor belt in the direction opposite to the rotation direction of the conveyor belt, and rubs the belt surface to adhere to the conveyor belt. Since the roll wire brush that scrapes off the existing carbide is provided, it is possible to reliably and satisfactorily remove the carbide entering the mesh of the conveyor belt and closing the mesh.

It is a schematic explanatory drawing of the band type dryer which enforces the method of this invention. It is a schematic explanatory drawing of the conventional band type dryer.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows an example of a band dryer 1 for carrying out the method of the present invention. The band dryer 1 forms a dehydrated sludge 2a, which is a viscous material, into a desired shape to form a formed sludge 2b. The sludge 2b is dried to obtain a dried sludge 2c (solid fuel), and a conveyor 3 that conveys the formed sludge 2b in a horizontal direction and a casing 4 that surrounds a part or all of the conveyor 3 to form a drying chamber. Then, the dewatered sludge 2a is formed into a desired shape to form the formed sludge 2b, and the molding machine 5 for supplying the formed sludge 2b onto the conveyor 3 and the drying air supplied into the drying chamber of the casing 4 are about 200 ° C. The warm air 6 is heated to a warm air 6 and the hot air 6 is blown onto the formed sludge 2b on the conveyor 3, and the dried sludge 2c adhering to the belt surface after the conveyor belt 3a of the conveyor 3 is turned back. (Attachment) The hot air 6 'is heated by heating a part of the hot air 6 based on the detection means 8 to be output and the detection signal of the adhering matter (dried sludge 2c adhering to the belt surface) from the detecting means 8. 'Is sprayed on the viscous material adhering to the belt surface of the conveyor belt 3a, and the hot air supply means 9 which ignites, burns, or gasifies the viscous material to form the carbide 2d and the carbide 2d adhered to the conveyor belt 3a is rubbed. And carbide scraping means 10 for removing.

  The conveyor 3 includes a driving sprocket 3b and a driven sprocket 3c that are rotatably disposed in a horizontal position at a predetermined distance, and a breathable endless conveying belt 3a wound around the sprockets 3b and 3c. And a driving motor (not shown) for rotationally driving the drive sprocket 3b, the hot air 6 is allowed to flow around the formed sludge 2b on the conveyor belt 3a through the mesh and through holes of the conveyor belt 3a. Is.

In addition, the conventionally well-known wire conveyor belt which has heat resistance and a softness | flexibility is used for the conveyance belt 3a of the conveyor 3. FIG.
The drive sprocket 3b may have a shape in which the tip of the tooth of the drive sprocket 3b reaches the upper part of the mesh so that the dried sludge 2c entering the mesh of the conveyor belt 3a can be pushed out.

  A scraper 11 for removing the dry sludge 2c on the conveyor belt 3a is provided near the drive sprocket 3b of the conveyor 3.

  The casing 4 is disposed so as to surround a portion (an intermediate portion and a downstream portion of the conveyor 3) excluding an upstream portion (left portion in FIG. 1) of the conveyor 3 to form a drying chamber. A plurality of air outlets 4a for extracting drying air (warm air 6) are formed in the upper part of 4, and an outlet 4b for discharging the dried sludge 2c is formed in the lower part of the casing 4, respectively.

  The molding machine 5 is disposed above the upstream portion of the conveyor 3 and close to the casing 4, and can supply the molding sludge 2 b to a location located in the casing 4 of the transport belt 3 a. ing.

  That is, the molding machine 5 includes a high-pressure vessel 5a having a molding chamber, a charging hopper 5b provided on the upper surface of the high-pressure vessel 5a, a screw shaft 5c having screw blades rotatably disposed in the high-pressure vessel 5a, a screw The screw extrusion type molding machine 5 includes a motor 5d for rotating the shaft 5c and a die 5e having a molding hole disposed at the tip of the high-pressure vessel 5a.

  According to this molding machine 5, the dewatered sludge 2a charged into the molding chamber from the charging hopper 5b is conveyed to the die 5e side by the rotationally driven screw shaft 5c and is pressed into the molding hole of the die 5e while being compressed. It is extruded from the molding hole 5e and molded into a rod shape.

  In this embodiment, the molding machine 5 is configured such that the dewatered sludge 2a can be formed into a rectangular bar shape with a cross-sectional shape of about 1 cm on a side, and a plurality of rod-shaped sludges 2b can be formed simultaneously. Further, the molding machine 5 is configured so that the rod-shaped molding sludge 2b can be supplied in a state of being arranged in the width direction on the transport belt 3a of the conveyor 3 and in a stacked state.

  The hot air supply means 7 is heated by a heat exchanger 12 that heats drying air using warm heat 22 such as sludge incineration exhaust heat (combustion exhaust gas) and the like, and is heated by the heat exchanger 12. A drying air circulation path 13 for circulating the drying air that has become hot air 6 between the casing 4 and the heat exchanger 12 of the band-type dryer 1, and for drying between the casing 4 and the heat exchanger 12. Moisture contained in the drying air (hot air 6) provided in the circulation fan 14 provided in the air circulation path 13 and the drying air circulation path 13 between the casing 4 and the circulation fan 14 A plurality of condensers 15 are disposed below the conveyor belt 3a on the upper side of the conveyor 3 along the longitudinal direction and the width direction of the conveyor belt 3a. A plurality of hot air outlets 16 for blowing the drying air And which are so as to circulate the drying air in order to reduce the amount of heat.

  In this embodiment, the hot air supply means 7 heats the drying air to about 200 ° C. to make the hot air 6 and can supply the hot air 6 into the casing 4 (drying chamber) of the band-type dryer 1. I have to.

  The reason why the drying air is heated to about 200 ° C. is that the hot air 6 ′ is about 300 ° C. or higher. If the drying air is heated at 300 ° C. or more, it is easily gasified and ignited when the moisture content of the sewage sludge is low. Because it becomes.

  The detection means 8 detects dry sludge 2c (adhered matter) adhering to the belt surface after the conveyor belt 3a is turned back, and is provided at a position below the drive sprocket 3b of the conveyor 3, and the conveyor belt 3a. The dried sludge 2c adhering to the belt surface immediately after the folding is detected.

  In this embodiment, a conventionally known detector such as an ultrasonic level meter or a microwave level meter is used as the detection means 8. This detector constantly measures the distance between the belt surface immediately after the conveyance belt 3a is folded back and the detector, and the dried sludge 2c adheres to the conveyance belt 3a because the distance between the belt surface and the detector is shortened. Can be detected.

  The hot air supply means 9 heats a part of the hot air 6 based on the detection signal of the adhering matter (dried sludge 2c adhering to the belt surface after the conveyance belt 3a is pushed back) from the detection means 8 to generate hot air. The hot air 6 'is blown onto the dried sludge 2c (adhered matter) adhering to the belt surface of the conveyor belt 3a, and the dried sludge 2c is ignited, combusted or gasified to form a carbide 2d.

  That is, the hot air supply means 9 is branched from the drying air circulation path 13, and a branch path 17 that branches a part of the warm air 6 (drying air) in the drying air circulation path 13 and the detection means 8. Based on the detection signal, an electric heater 18 (comprising a power source 18a, a heating body 18b, and a control unit 18c) that heats the hot air 6 (drying air) in the branch passage 17 to form hot air 6 ', and from the branch passage 17 The hot air is detected by detecting the temperature of a plurality of hot air outlets 19 for blowing the hot air 6 'to the dried sludge 2c adhering to the belt surface of the conveyor belt 3a and the temperature of the hot air 6' sent from the electric heater 18 to the hot air outlet 19. And a temperature controller 20 for controlling the electric heater 18 so that the temperature of 6 'becomes about 300 ° C, and the hot air outlet 19 is positioned below the viscous material at the initial stage of molding on the conveyor belt 3a and Of the conveyor belt 3a It is to be arranged in a position opposed to the belt surface after return Ri.

  In this embodiment, the hot air supply means 9 heats hot air 6 (drying air) of about 200 ° C. to about 300 ° C. to form hot air 6 ′, and this hot air 6 ′ adheres to the belt surface of the conveyor belt 3a. The dried sludge 2c is sprayed. Further, when the dried sludge 2c is not attached to the transport belt 3a, the hot air supply means 9 does not operate the electric heater 18 and blows out drying air (hot air 6) of about 200 ° C. from the hot air outlet 19. It is configured.

The reason why the drying air is heated to about 300 ° C. is that when the drying air is heated to about 300 ° C. or more to become hot air 6 ′, the dried sludge 2 c blown with the hot air 6 ′ is ignited, burned, or gasified. This is because the burned and brittle carbide 2d is easily peeled off from the conveyor belt 3a. The temperature of the hot air 6 ′ is preferably 300 ° C., but may be a temperature of 300 ° C. or lower or a temperature of 300 ° C. or higher as long as the dried sludge 2c is ignited, combusted or gasified to become brittle carbide 2d.
Similarly, the reason why the temperature of the hot air 6 is about 200 ° C. is that the sludge used in this embodiment is suitable for drying without burning and without gasification. Therefore, the temperature of the hot air 6 is preferably 200 ° C., but may be higher (but lower than the hot air 6 ′) or lower.

  The carbide scraping means 10 includes a roll wire brush 10a that is rotatably disposed at a position obliquely below the driven sprocket 3c and in the vicinity of the conveyor belt 3a, and the roll wire brush 10a is opposite to the rotation direction of the conveyor belt 3a. A driving motor (not shown) that rotates in a direction is provided, and the surface of the belt 2b is rubbed by a roll wire brush 10a so that the carbide 2d adhering to the conveying belt 3a is rubbed off.

  In the above embodiment, the intermediate portion and the downstream portion of the conveyor 3 are surrounded by the casing 4. However, in other embodiments, the entire conveyor 3 may be surrounded by the casing 4.

  Moreover, in said embodiment, although the warm air 6 (drying air of about 200 degreeC) was blown toward the shaping | molding sludge 2b on the conveyance belt 3a of the conveyor 3 from the downward toward the upper direction, other embodiment In this case, the hot air 6 may be blown from the upper side to the lower side on the formed sludge 2b on the conveyor belt 3a.

  Further, in the above embodiment, the molding machine 5 can form the dewatered sludge 2a into a rod shape. However, in other embodiments, the molding machine 5 can form the dewatered sludge 2a into a plate shape or other shapes. It may be possible to mold.

  In addition, in the above embodiment, the electric heater 18 is used as the heat source of the hot air supply means 9, and the hot air 6 is heated by the electric heater 18 to become the hot air 6 '. However, in other embodiments, May use the heat 22 such as sludge incineration exhaust heat (combustion exhaust gas) as the heat source of the hot air supply means 9 to change the hot air 6 into the hot air 6 '.

  Next, a case where the dewatered sludge 2a is dried using the band dryer 1 having the above-described configuration will be described.

  The dewatered sludge 2a obtained by dewatering the sewage sludge has a moisture content of about 80% (wet basis) and is put into a molding machine 5 to be formed into a plurality of rods. It is supplied to the upper surface of the conveyor belt 3a. At this time, the supply speed of the molding sludge 2b and the conveyance speed of the conveyor belt 3a are set to the same speed, and the molding sludge 2b is prevented from being broken.

  The formed sludge 2b supplied to the conveyor belt 3a is warm air 6 (about 200) blown upward from the hot air outlet 19 and the hot air outlet 16 while being conveyed in the casing 4 (drying chamber) by the conveyor belt 3a. Drying sludge 2c is brought into contact with the drying air (° C drying air). At this time, since the formed sludge 2b is formed in a rod shape having a rectangular cross section, a surface area in contact with the warm air 6 is ensured. Further, the surface of the formed sludge 2b is dried and solidified to enable shape retention, and dust generation and odor are suppressed. Further, the formed sludge 2b on the conveyor belt 3a is dried over about 60 minutes by hot air 6 of about 200 ° C. supplied from below.

  The formed sludge 2b dried by the warm air 6 (drying air of about 200 ° C.) is peeled off from the belt surface of the conveyor belt 3a at the turning point of the conveyor belt 3a and is removed by the scraper 11, and is discharged from the casing 4 It is discharged from 4b. At this time, when the drive sprocket 3b having a shape in which the tip of the tooth of the drive sprocket 3b reaches the upper part of the mesh is used, the dried sludge 2c entering the mesh of the conveyor belt 3a can be pushed out, and the dried sludge 2c is conveyed. It becomes easy to peel from the belt 3a.

  By the way, the dried sludge 2c obtained by drying the formed sludge 2b has a moisture content of about 70% (based on the amount of moisture) and has high adhesion. For this reason, the dried sludge 2c may not adhere to the belt surface and peel off even when the conveyor belt 3a passes the turning point.

  The dried sludge 2c that does not peel off from the conveyor belt 3a even when the conveyor belt 3a passes the turning point is detected by the detector of the detecting means 8.

  When the detector detects the dried sludge 2c adhering to the conveyor belt 3a, a detection signal from the detector is sent to the control unit 18c of the electric heater 18, and the electric heater 18 is turned on to pass through the branch path 17. The flowing drying air (warm air 6) at about 200 ° C. is heated into hot air 6 ′ at about 300 ° C.

  Hot air 6 ′ of about 300 ° C. is blown out from the hot air outlet 19 and blown onto the dried sludge 2 c attached to the conveyor belt 3 a. At this time, the dry sludge 2c adhering to the conveyor belt 3a has a high moisture content of about 70% (humidity standard) and is a small mass without air permeability. It is ignited and burned by being formed, or it is gasified and burnt to become brittle carbide 2d. The contact time with the hot air 6 'of about 300 ° C. necessary for carbonization of the dried sludge 2c adhering to the conveyor belt 3a is 10 to 20 minutes. Therefore, the speed of the conveyor belt 3a and a plurality of hot air The arrangement position of the outlet 19 is set so that the time can be taken.

  Since the carbide 2d on the conveyor belt 3a is burnt and fragile, it is separated from the conveyor belt 3a by the roll wire brush 10a of the carbide scraping means 10 rotating in the direction opposite to the rotation direction of the conveyor belt 3a, and collected. It is discharged to the box 21. At this time, since the roll wire brush 10a enters the mesh of the conveyor belt 3a even if the carbide 2d enters the mesh of the conveyor belt 3a, the carbide 2d blocking the mesh of the conveyor belt 3a is surely and satisfactorily removed. Can do.

  The hot air 6 'after being blown onto the dried sludge 2c adhering to the conveyor belt 3a is used to dry the dried sludge 2c at the initial stage of molding on the conveyor belt 3a, and the thermal energy is effectively used. At this time, the molding sludge 2b at the initial stage of molding is high in moisture content, so that it is dried well without being ignited and burned or gasified by the hot air 6 'in a short time.

  The hot air 6 'containing moisture evaporated by drying the molding sludge 2b in the early stage of molding and the hot air 6' (drying air) containing moisture evaporated by drying the molding sludge 2b are extracted from the air outlet 4a. After being dehumidified by the condenser 15, it is reheated by the heat exchanger 12, supplied into the casing 4, and circulated and used as a drying heat source.

  In the above embodiment, the dehydrated sludge 2a is dried using the band dryer 1, but in addition to the dehydrated sludge 2a, livestock excrement, food residue, fertilizer, etc. with high water content and adhesion. The viscous material may be dried.

  1 is a band dryer, 2a is dewatered sludge, 2b is formed sludge, 2c is dried sludge, 2d is carbide, 3 is a conveyor, 3a is a conveyor belt, 3b is a drive sprocket, 3c is a driven sprocket, 4 is a casing, 4a Is an air outlet, 4b is an outlet, 5 is a molding machine, 5a is a high pressure vessel, 5b is a loading hopper, 5c is a screw shaft, 5d is a motor, 5e is a die, 6 is hot air, 6 'is hot air, 7 Is hot air supply means, 8 is detection means, 9 is hot air supply means, 10 is carbide scraping means, 10a is a roll wire brush, 11 is a scraper, 12 is a heat exchanger, 13 is an air circulation path for drying, and 14 is Circulating fan, 15 is a condenser, 16 is a hot air outlet, 17 is a branch path, 18 is an electric heater, 18a is a power source, 18b is a heating element, 18c is a control unit, 19 is a hot air outlet, and 20 is temperature control. vessel, 1 collection box 22 is heat such sludge incineration waste heat.

Claims (4)

Viscous material formed by a molding machine is supplied onto a breathable endless conveyor belt, and hot air is blown from above or below to the viscous material on the conveyor belt in the other direction. In a band-type dryer configured to dry the viscous material on the belt, the viscous material adhering to the belt surface after the conveyor belt is folded is detected by the detection means, and hot air is detected based on the detection signal from the detection means. A part of the hot air branched from the hot air supply means is heated by the supply means to form hot air that ignites, burns, or gasifies the viscous material, and the hot air adheres to the belt surface after the conveyor belt is folded. A method for removing deposits from a band drier, characterized in that a viscous material is ignited, burned or gasified to form a carbide, and the carbide is scraped off by a carbide scraping means.   2. The band according to claim 1, wherein the hot air is used to dry the viscous material at the initial stage of molding on the conveyor belt after being sprayed on the viscous material adhering to the belt surface of the conveyor belt. Method of removing deposits from the dryer. Viscous material formed by a molding machine is supplied onto a breathable endless conveyor belt, and hot air is blown from above or below to the viscous material on the conveyor belt in the other direction. In a band-type dryer configured to dry the viscous material on the belt, a detection means for detecting the viscous material adhering to the belt surface after the conveyance belt is turned back, and hot air based on a detection signal from the detection means The hot air is blown onto the viscous material adhering to the belt surface of the conveyor belt to ignite, burn, or gasify the viscous material to form carbide, and the carbide adhering to the conveyor belt. and a carbide scraping means scrape the hot air supply means includes a branch passage that branches a part of the hot air from the hot air supplying means, an electric heater and hot air to heat the warm air branch passage Hot air from the branch path is blown against the viscous material adhering to the belt surface of the conveyor belt, and the temperature of the hot air sent from the electric heater to the hot air outlet is detected, and the temperature of the hot air ignites and burns the viscous material. Or a temperature controller that controls the electric heater so that the gasified temperature is reached, and the hot air outlet is located below the viscous material at the initial stage of molding on the conveyor belt and after the conveyor belt is turned back. A band type dryer characterized by being disposed at a position facing the surface . The carbide scraping means includes a roll wire brush that rotates in a direction opposite to the rotation direction of the transport belt at a position near the belt surface of the transport belt, and scrapes the carbide adhering to the transport belt by rubbing the belt surface. band type dryer according to claim 3, characterized in that there.

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