Dryer

Abstract

The present invention provides a dryer that prevents the enlarged granules of the material to be dried from becoming trapped inside the main shell. [Solution] The device comprises a cylindrical main shell 2, a plurality of heating tubes 43 arranged at intervals from each other within the main shell 2, rotating around a rotation axis O, and drying the material to be dried R by contacting it with the material to be dried R introduced into the main shell 2, a lifter 51 that rotates together with the heating tubes 43 within the main shell 2 and scrapes the material to be dried R along the inner circumferential surface 20 of the main shell 2, and a crusher 3 that crushes the material to be dried R. The main shell 2 has an inlet 25 formed to receive the material to be dried R scraped up by the lifter 51, and the crusher 3 is connected to the inlet 25.

Description

Technical Field

[0001] The present invention relates to a dryer for drying an object to be dried.

Background Art

[0002] In a process of recycling or volume reduction of sewage treatment sludge, animal and vegetable residues, food residues or sludge-like waste, etc., a dryer for drying an object to be dried such as sludge or a dryer for chemical products such as resin, medical and agricultural chemicals, food, etc., a dryer including a main body shell and a plurality of heating tubes that rotate within the main body shell is known (see, for example, Patent Document 1, etc.). The dryer of this Patent Document 1 is a conduction heat transfer type that heats the heating tubes by flowing heating steam through the heating tubes and transfers heat to the object to be dried by bringing the object to be dried into contact with the heated heating tubes.

[0003] The main body shell includes an inlet for introducing the object to be dried and an outlet for discharging the dried object. Between the inlet and the outlet, the object to be dried that has been introduced is dried while staying within the main body shell. The main body shell is installed on a machine frame or the like in a state of extending in a horizontal direction or in a direction inclined slightly downward from the inlet side toward the outlet side. The plurality of heating tubes are arranged at a predetermined interval from each other and form a multi-tube heating tube that is a tube bundle as a whole. This multi-tube heating tube is rotatably arranged within the main body shell around a rotation axis along the extending direction of the main body shell. Further, within the main body shell, as a scraping member that rotates together with the multi-tube heating tube when the multi-tube heating tube rotates and scrapes up the object to be dried staying within the main body shell, an angle arranged on the outer peripheral side of the multi-tube heating tube and a lifter attached to this angle are provided.

[0004] In this dryer, the material to be dried, introduced through the inlet, is scraped up by a rotating scraping member and, as it falls, comes into contact with each rotating heating tube, causing moisture to evaporate from the material and drying it. In other words, the outer surface of each heating tube becomes a heat transfer surface that transmits heat to the material being dried. In addition, the material is also dried by being agitated as the multi-tube heating tubes rotate. As the material is repeatedly brought into contact with each heating tube and agitated, its moisture content decreases and it gradually moves towards the discharge port inside the main shell, and eventually it is discharged as dried material from the discharge port.

[0005] Here, the material to be dried, which has just been introduced from the input port and has a high moisture content, tends to stick together and form large granules. It can also form even larger lumps than these granules. Furthermore, the material to be dried, which has just been introduced from the input port and has a high moisture content, can form lumps between the scraping members and bridge between them. Hereafter, the formation of large granules and lumps of the material to be dried will be collectively referred to as "granulation."

[0006] Depending on the properties of the material being dried and the arrangement of the heating tubes, for example, if the material has grown to a size exceeding 10 mm, the larger the particle size, the less likely it is to penetrate between the heating tubes positioned inside the scraping member. This results in insufficient contact between the material and the heating tubes. This leads to a decrease in the drying capacity of the dryer and a reduction in the processing volume. Additionally, the larger particle size of the material creates resistance to the rotation of the heating tubes and scraping member, increasing the power consumption of the dryer.

[0007] One measure to prevent this granulation is to pre-load the dryer shell with dried material as a bed material before using the dryer, thereby reducing the apparent moisture content of the material to be dried. Furthermore, during dryer operation, the material to be dried dries within the shell and becomes a low-moisture-content retained material, which acts as a bed material to reduce the apparent moisture content of the material to be dried that is then loaded. However, because the dispersion, shape, degree of granulation, and moisture content of the retained material within the shell are not constant, granulation can still occur even with pre-loading the bed material. When granulation occurs, it becomes necessary to stop the dryer, remove the material from the shell, load new bed material, and then restart operation, which is a very complicated process.

[0008] Another possible solution is to reduce the amount of material to be dried within the main shell by controlling the input rate, such as intermittently feeding the material through the input port, thereby accelerating drying. However, reducing the amount of material remaining in the shell would lead to a problem of reduced processing capacity in the dryer.

[0009] The dryer described in Patent Document 1 has an outlet on the discharge side of the main shell and a return port on the input side of the main shell as a measure to prevent the material from becoming too large, and a screw conveyor is placed between the outlet and the return port. In this dryer, a portion of the dried material that has moved to the discharge side of the main shell is received at the outlet, transported by the screw conveyor, and returned to the input side of the main shell from the return port. As a result, the returned dried material acts as a bed material, reducing the apparent moisture content of the material to be dried on the input side. This is intended to prevent the material from becoming too large. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 2006-17335 [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] In the dryer described in Patent Document 1, it is possible to suppress the occurrence of granulation to some extent by returning a portion of the dried product to the input side. However, whether or not granulation occurs depends greatly on the properties of the material to be dried that is introduced into the main shell, the dispersion, shape, degree of granulation, and moisture content of the remaining material, so granulation may still occur even if a portion of the dried product is returned to the main shell. Furthermore, once granulation occurs, the material to be dried that is not sufficiently dried will remain in the main shell. In addition, there is a risk that the material to be dried that is not sufficiently dried will move to the outlet and be returned to the return port. In that case, the function of reducing the moisture content of the material to be dried will be weakened, which could lead to a vicious cycle in which material with even higher moisture content moves to the outlet and is returned to the return port, so there is still room for improvement.

[0012] In view of the above circumstances, the present invention aims to provide a dryer that prevents the enlarged granules of the material to be dried from becoming trapped inside the main shell. [Means for solving the problem]

[0013] The dryer of the present invention, which solves the above problems, A cylindrical body shell, The aforementioned main body shell is provided with a plurality of heating tubes that are spaced apart from each other, rotate around a rotation axis, and dry the material to be dried by coming into contact with the material to be dried placed inside the main body shell, A lifter that rotates together with the heating tube within the main body shell and scrapes up the material to be dried along the inner surface of the main body shell, The system includes a crusher for crushing the material to be dried, The main shell is formed with an opening for receiving the material to be dried, which has been scraped up by the lifter. The crusher is characterized by being connected to the receiving port.

[0014] This dryer prevents the dried material from remaining in the main shell in a large granular state by crushing the material that has been lifted up by the lifter. Furthermore, the large granular dried material that is easily lifted up by the lifter can be efficiently crushed by the crusher.

[0015] Here, the lifter may rotate with a predetermined gap between it and the inner circumferential surface. The crusher may mainly crush the dried material that has been enlarged. The crusher may also crush the dried material received by the receiving port. Furthermore, the crusher may have a guide member that guides the crushed dried material to flow down toward the heating tube. The receiving port may be formed on the inner circumferential surface. The receiving port may be formed by a hole penetrating the circumferential wall of the main body shell.

[0016] In this dryer, The crusher may be detachably attached to the main body shell.

[0017] This makes maintenance of the crusher easier. Furthermore, when handling materials to be dried that are not likely to become large in size, the dryer can be used without attaching the crusher to the main shell.

[0018] Furthermore, in this dryer, The main body shell may have multiple receiving ports formed at intervals along the axial direction of the rotation axis.

[0019] Since the crushing position of the material to be dried can be changed to the axial direction by the crusher, the crusher can be installed at the position where granulation is most likely to occur, and the granulated material to be dried can be crushed more efficiently.

[0020] Here, the main body shell may have a mounting portion for attaching the crusher formed in the receiving portion.

[0021] Furthermore, in this dryer, the main body shell has a plurality of inlets into which the material to be dried is fed, formed at intervals along the axial direction, and the receiving port may be formed at a position overlapping the inlet in the axial direction.

[0022] Since the material to be dried has a high water content immediately after being fed through the inlet and is thus easy to granulate, by forming the attachment portion at a position overlapping the inlet in the axial direction, the granulated material to be dried can be more efficiently crushed by the crusher.

[0023] In addition, in this dryer, the lifter may be in the form of a comb blade or have a plurality of holes formed therein.

[0024] In this form, the lifter mainly scrapes up the material to be dried that is larger granulated than the interval between the comb blades or the size of the holes, so that the material to be dried that is larger granulated can be more efficiently crushed.

[0025] Furthermore, in this dryer, it includes a thermometer for measuring the temperature of the material to be dried inside the main body shell, and a control device for controlling the crusher, and the control device may perform control to reduce the crushing amount in the crusher when the temperature measured by the thermometer is below a predetermined temperature.

[0026] When the temperature of the material to be dried inside the main body shell is below the predetermined temperature, the water content is too high and the material to be dried may be in a muddy state and difficult to crush. Therefore, by reducing the crushing amount of the crusher, unnecessary power consumption in the crusher can be suppressed. Note that reducing the crushing amount of the crusher also includes stopping the crusher, and the same applies hereinafter.

[0027] Furthermore, in this dryer, An actuator for rotating the heating tube and the lifter, A monitoring means for monitoring the operating load of the actuator, The system includes a control device for controlling the crusher, The control device may also perform control to reduce the amount of crushing in the crusher when the operating load monitored by the monitoring means is less than a predetermined load.

[0028] When the load on the actuator decreases below a predetermined load, it is highly likely that the material being dried inside the main shell has not been compressed into larger particles. Therefore, by reducing the amount of material being crushed by the crusher, unnecessary power consumption in the crusher can be suppressed. [Effects of the Invention]

[0029] According to the present invention, it is possible to provide a dryer that prevents the enlarged particles of the material to be dried from becoming trapped inside the main shell. [Brief explanation of the drawing]

[0030] [Figure 1] This is a front view of the dryer, which corresponds to one embodiment of the present invention. [Figure 2] This is a front view showing a section of the dryer shown in Figure 1. [Figure 3] Figure 1 shows a cross-sectional view of the dryer AA. [Figure 4] This is a cross-sectional view similar to Figure 3, showing the multi-tube heating element and angle rotating while the material to be dried remains inside the main shell shown in Figure 1. [Figure 5] This block diagram shows the control configuration of the dryer as shown in Figure 1. [Figure 6] This is a front view showing the dryer shown in Figure 1 with the crusher replaced by a single unit. [Figure 7] This figure shows a modified version of the lifter shown in Figure 3. [Figure 8] This is an enlarged cross-sectional view showing a modified example of the return member shown in Figure 3. [Modes for carrying out the invention]

[0031] Embodiments of the present invention will be described below with reference to the drawings. One embodiment of the present invention is a conduction heat transfer dryer for drying wastewater treatment sludge, animal and plant residues, food residues, muddy waste, chemical products, pharmaceuticals and agricultural chemicals, or food products. The material to be dried by the dryer is not particularly limited.

[0032] Figure 1 is a front view of dryer 1, which corresponds to one embodiment of the present invention.

[0033] As shown in Figure 1, the dryer 1 comprises a main shell 2 and a crusher 3. The main shell 2 is generally cylindrical with both ends closed. The main shell 2 is supported by a machine frame (not shown) that extends horizontally. In Figure 1, the extension direction of the main shell 2 is left to right. This extension direction of the main shell 2 coincides with the axial direction of the rotation axis of the multi-tube heating tube 4, which will be described later. Hereafter, this axial direction of the multi-tube heating tube 4 (the extension direction of the main shell 2) may be simply referred to as the axial direction.

[0034] The main shell 2 is provided with an inlet 21, an outlet 22, a carrier gas inlet 23, an exhaust port 24, a receiving inlet 25, a thermometer mounting pipe 26, and a dryer drive motor 27. The inlet 21 is the opening into which the material to be dried R is introduced, and four of them are provided at predetermined intervals in the axial direction at the upper end of the main shell 2. Depending on the axial length of the main shell 2, there may be one to three or five or more inlet 21. The main shell 2 also has a viewing window (not shown) that allows the inside of the main shell 2 to be visually inspected.

[0035] The discharge port 22 is an opening through which the material to be dried R, introduced from the input port 21, dries while remaining inside the main shell 2, reducing its moisture content and becoming the dried material D that is then discharged. This discharge port 22 is located on the right side of the main shell 2 in Figure 1, on the side of the main shell 2 (the side facing the viewer in Figure 1). The discharge port 22 is equipped with a height-adjustable weir member 221, and by adjusting the height of this weir member 221, the height of the lower end of the opening of the discharge port 22 can be adjusted. This adjustment allows for the adjustment of the amount of material to be dried R that remains inside the main shell 2. A chute 222 is also located in the part of the main shell 2 where the discharge port 22 is provided. The material to be dried R, introduced from the input port 21, moves from left to right inside the main shell 2 as shown in Figure 1, and is eventually discharged from the discharge port 22 and taken out from the lower end of the chute 222. In the main shell 2 shown in Figure 1, the left side is the input port side, and the right side is the discharge port side. The main body shell 2 may also be installed on the machine frame or the like in a state where it extends in a direction that is slightly inclined downward from the input side to the discharge side.

[0036] The carrier gas inlet 23 is an inlet for introducing carrier gas, which is supplied by a supply blower and heated to approximately 120°C by a heater, into the main body shell 2. The exhaust inlet 24 is an inlet for exhausting vapor evaporated from the material to be dried R, along with the carrier gas introduced from the carrier gas inlet 23, to the outside of the main body shell 2. The carrier gas introduced into the main body shell 2 from the carrier gas inlet 23 flows over the upper part of the main body shell 2, which is the surface layer of the material to be dried R that remains inside the main body shell 2, and is exhausted from the exhaust inlet 24 along with the vapor evaporated from the material to be dried R.

[0037] The exhaust path connected to the exhaust port 24 is equipped with a dust collector and an exhaust blower (not shown). The gas exhausted from the exhaust port 24, i.e., steam and carrier gas, is sent to the dust collector, where it undergoes predetermined processing such as removal of fine particles, and then exhausted outdoors via the exhaust blower, etc. In addition, a portion of the exhaust air exhausted via the exhaust blower is introduced into the main body shell 2 as a carrier gas from a second carrier gas port (not shown).

[0038] The receiving ports 25 are formed at four intervals along the direction in which the main body shell 2 extends, on the side surface of the main body shell 2 (the side surface on the near side of the paper in Figure 1). The receiving ports 25 are formed in positions that overlap with the four input ports 21 in the axial direction. Preferably, the receiving ports 25 and the input ports 21 are in a positional relationship where at least a portion of the openings overlap with each other in the axial direction, more preferably the center of one opening overlaps with the other opening in the axial direction, and even more preferably the centers of their respective openings are at the same position in the axial direction. These receiving ports 25 are formed by through holes provided on the side surface of the main body shell 2. Mounting portions for detachably attaching the crusher 3 are formed near each receiving port 25 of the main body shell 2.

[0039] The thermometer mounting tube 26 is a tube in which a thermometer 261 (see Figure 5) for measuring the temperature of the material R to be dried inside the main shell 2 is placed. There are four thermometer mounting tubes 26, the same number as the input port 21 and receiving port 25, and they are formed on the side of the main shell 2 extending downwards. These thermometer mounting tubes 26 are positioned to overlap with the receiving port 25 in the axial direction. Therefore, the thermometer 261 is also positioned to overlap with the receiving port 25 in the axial direction.

[0040] The dryer drive motor 27 is the drive source that rotates the multi-tube heating tube 4 (see Figure 2) and angle 5 (see Figure 2) located inside the main body shell 2, which will be described later. This dryer drive motor 27 is an example of an actuator. The driving force generated by the dryer drive motor 27 is transmitted to the hollow shaft 41 on the input side via the drive transmission mechanism 271, causing the hollow shaft 41 to rotate.

[0041] The four crushers 3 are each connected to the receiving inlet 25 so as to close the receiving inlet 25. These crushers 3 are detachably attached to mounting points formed on the side of the main body shell 2 by bolts (not shown). Making the crushers 3 detachable makes maintenance of the crushers 3 easier as they can be removed for maintenance. All four crushers 3 have the same configuration, and each has a crusher body 31 and a crusher drive motor 32. The configuration of the crushers 3 will be described in detail later.

[0042] Figure 2 is a front view showing a section of the dryer 1 shown in Figure 1. Note that in Figure 2, the internal components are simplified to make the internal structure of the main shell 2 easier to see.

[0043] As shown in Figure 2, the main shell 2 contains a multi-tube heating tube 4 and multiple angles 5. The multi-tube heating tube 4 is rotatably arranged within the main shell 2 around a rotation axis. The multi-tube heating tube 4 has a hollow shaft 41, a rotary joint 42, multiple heating tubes 43, an inlet-side header 44, and an outlet-side header (not shown). The hollow shaft 41 is provided at each end of the rotation axis of the multi-tube heating tube 4. This hollow shaft 41 is supported by a bearing (not shown) and rotates when driven by the dryer drive motor 27. As the hollow shaft 41 rotates, all the heating tubes 43, the inlet-side header 44, the outlet-side header, and the angles 5 rotate. The rotary joint 42 is connected to each hollow shaft 41.

[0044] Multiple heating tubes 43 extend along the rotation axis of the multi-tube heating tube 4, spaced apart from each other. Each heating tube 43 is supplied with saturated steam introduced from the rotary joint 42 on the inlet side. A disc-shaped inlet-side header 44 is provided at the inlet-side end of each heating tube 43. In Figure 2, the outlet side is hidden as it is depicted as the outer surface of the main body shell 2, but an outlet-side header is provided at the outlet-side end of each heating tube 43. The outlet-side header has the same shape as the inlet-side header 44 and is positioned symmetrically to the inlet-side header 44 in Figure 2.

[0045] The inlet-side header 44 and the outlet-side header are hollow, with a space through which gas passes. Each of the multiple heating tubes 43 has its outlet end inserted into the outlet-side header and its inlet end inserted into the inlet-side header 44. When saturated steam is supplied from the rotary joint 42 on the inlet side, this saturated steam passes from the inlet-side header 44 through each heating tube 43 to the outlet-side header. This maintains the heating tubes 43 at a nearly constant temperature in the axial direction. The condensate generated from the saturated steam in the heating tubes 43 generally flows towards the outlet side and accumulates at the bottom of the outlet-side header. The condensate accumulated in the outlet-side header is drained to the outside of the dryer 1 by a drainage device (not shown).

[0046] Each of the multiple angles 5 is stretched across the input-side header 44 and the output-side header at a predetermined rotational distance from each other on the outer circumference of the heating tube 43. Therefore, as described above, when the hollow shaft 41 rotates, the angles 5 also rotate. The angles 5 are made of, for example, equal-leg angle steel. Multiple lifters 51 and feed vanes 52 are fixed to the angles 5 at intervals in the axial direction.

[0047] The angle 5 functions as a frame that reinforces the multi-tube heating tube 4 and also serves as a mounting base for the lifter 51 and the feed vane 52. When the multi-tube heating tube 4 rotates, the angle 5 and the lifter 51 and feed vane 52 fixed to the angle 5 also rotate together, and the angle 5, lifter 51 and feed vane 52 each scrape up the material to be dried R that is retained inside the main body shell 2. In other words, in this embodiment, the angle 5, lifter 51 and feed vane 52 correspond to an example of scraping members.

[0048] The lifter 51 is positioned closest to the inner wall of the main body shell 2, and its rotation scrapes up the material to be dried R that remains inside the main body shell 2. The lifter 51 is attached to the angle 5 in a spiral shape with the rotation axis of the multi-tube heating tube 4 as its central axis. The feed vane 52 is also fixed to the angle 5 at an angle with respect to the axial direction. As a result, the lifter 51 and feed vane 52 gradually move the material to be dried R that remains inside the main body shell 2 towards the discharge port by scraping it up through rotation.

[0049] Figure 3 is a cross-sectional view AA of the dryer 1 shown in Figure 1.

[0050] As shown in Figure 3, the main body shell 2 is a hollow member having a cross-sectional shape in which a roughly U-shaped lower portion and an arc-shaped upper portion are joined. Inside the main body shell 2, a drying space S1 is formed, which is a space defined by the inner circumferential surface 20 of the main body shell 2, for drying the material to be dried R (see Figure 4). The heating tube 43, the input side header 44 (see Figure 2), the outlet side header (not shown), the angle 5, the lifter 51, and the feed vane 52 (see Figure 2) are arranged in this drying space S1 and rotate clockwise in Figure 3, as indicated by the thick curved arrows. Figure 3 also shows a virtual rotation axis O, which is the rotational axis of the heating tube 43, the input side header 44, the outlet side header, the angle 5, the lifter 51, and the feed vane 52.

[0051] The heating tubes 43 are made of stainless steel pipes with a nominal diameter of 50A. Multiple heating tubes 43 are arranged in multiple rows in a regular hexagonal shape around the rotation axis O. A gap of 40 to 50 mm is formed between the heating tubes 43. The diameter of the heating tubes 43 and the gaps are set appropriately depending on the type and amount of the material to be dried R (see Figure 4) and the size of the main shell 2. The material to be dried R in the drying space S1 is scraped up along the scraping surface 20a of the inner circumferential surface 20 of the main shell 2 by the angle 5, lifter 51, or feed vane 52 (see Figure 2). This scraping surface 20a is the surface that the material to be dried R inside the main shell 2 comes into contact with and is scraped up when it is scraped up by the rotation of the lifter 51. The material to be dried R, which is lifted up by the angle 5, lifter 51, or feed blade 52, comes into contact with the heating tube 43 and dries as it falls through the gaps in the heating tube 43 to the lower part of the drying space S1.

[0052] The receiving port 25 is located above the rotation axis O and is formed on the upper part of the scraped surface 20a. Since larger particles of the material to be dried R are more easily absorbed into the receiving port 25 than finely granulated or powdered materials R, it is preferable that the receiving port 25 is formed above the downward-convex arc-shaped portion of the main shell 2 (in this embodiment, on the vertically cut surface of the main shell 2) or on the upper part of the scraped surface 20a. However, it may be formed on the downward-convex arc-shaped portion as long as it is formed on the scraped surface 20a, and does not have to be on the upper part of the scraped surface 20a. Similarly, the receiving port 25 may be formed below the rotation axis O.

[0053] Angle 5 extends along the axial direction, with one end in the axial direction fixed to the outer circumference of the inlet-side header 44 and the other end in the axial direction fixed to the outer circumference of the outlet-side header, thereby spanning between the inlet-side header 44 and the outlet-side header.

[0054] As described above, the lifter 51 is arranged spirally with the rotation axis O as the centerline. Figure 3 shows only the lifter 51 as it is cut in cross section AA. In the semicircular portion on the lower side of the main shell 2, the lifter 51 is attached to the angle 5, protruding radially in a virtual circle centered on the rotation axis O, such that the distance between its tip and the inner surface of the main shell 2 is 20 mm to 30 mm. This lifter 51 is a plate-like shape with a V-shaped cross-section formed by bending a rectangular steel plate. The base of the lifter 51 is fixed to the radially protruding portion of the angle 5, so that the tip is bent toward the downstream side in the rotational direction relative to the radial direction. Because the tip of the lifter 51 is bent toward the downstream side in the rotational direction, the material to be dried R (see Figure 4) that is scooped up is less likely to fall. The distance between the lifter 51 and the inner surface of the main shell 2, and the cross-sectional shape of the lifter 51 are set appropriately depending on the type and amount of material to be dried R and the size of the main shell 2.

[0055] As described above, the crusher 3 comprises a crusher body 31 and a crusher drive motor 32 (see Figure 1). The crusher body 31 comprises a crusher shell 310, crushing rollers 311, an air discharge pipe 312, and a return member 313. The crusher shell 310 is the housing of the crusher body 31, and the crusher internal space S2 is formed inside it. The drying space S1 and the crusher internal space S2 are continuous via an inlet 25.

[0056] The crushing roller 311 is a cylindrical roller positioned in the internal space S2 of the crusher, with numerous crushing ridges projecting radially from its outer circumferential surface. The crushing ridges are projections extending parallel to the rotational axis of the crushing roller 311. The crushing roller 311 rotates when driven by the crusher drive motor 32 (see Figure 1). The direction of the rotational axis of the crushing roller 311 is the same as the axial direction. As shown by the thin curved arrows in Figure 3, the crushing roller 311 rotates clockwise in Figure 3. Therefore, the crushing roller 311 rotates in the same direction as the heating tube 43, angle 5, lifter 51, and feed blades 52 (see Figure 2). The distance between the crushing roller 311 and the inner circumferential surface of the crusher shell 310 gradually narrows in the lower right of Figure 3, and is the narrowest and most uniform distance in the approximately 180-degree section from the lower right to the upper left of Figure 3, and gradually widens above the crushing roller 311. In this narrowest section, the distance between the tip of the crushing ridge and the inner surface of the crusher shell 310 is, for example, about 5 mm. Also, the distance between the portion of the crushing roller 311 where no crushing ridges are formed and the inner surface of the crusher shell 310 is, for example, 15 mm. The distance between the crushing roller 311 and the inner surface of the crusher shell 310, and the protrusion length of the crushing ridges are set appropriately depending on the type and amount of material to be dried R and the size of the main shell 2. Furthermore, one or more of the four crushers 3 may be set to have different spacing and protrusion lengths than the other crushers 3.

[0057] The air discharge pipe 312 is positioned in a section where the gap between the crushing roller 311 and the inner surface of the crusher shell 310 gradually widens. An outlet 3121 is formed at one end of the air discharge pipe 312, and the other end is connected to an air supply device such as a compressor (not shown). The outlet 3121 is located in the crusher's internal space S2. Air supplied from the air supply device is blown out from the outlet 3121 toward the crushing roller 311. As a result, the material to be dried after crushing R on the surface of the crushing roller 311 is blown away from the surface of the crushing roller 311, separated from the crushing roller 311, and carried onto the return member 313.

[0058] The return member 313 is a plate-shaped member with one end positioned slightly downstream of the outlet 3121 in the rotational direction of the crushing roller 311, facing the crushing roller 311, and the other end protruding into the drying space S1. One end of the return member 313 is positioned close to the crushing ridges of the rotating crushing roller 311. The other end of the return member 313 is positioned lower than the other end and close to the tip of the rotating lifter 51. The distance between the other end of the return member 313 and the tip of the lifter 51 when they are closest is preferably 20 mm to 30 mm, similar to the distance between the tip of the lifter 51 and the inner circumferential surface of the main body shell 2. This return member 313 is an example of a guide member.

[0059] Figure 4 is a cross-sectional view similar to Figure 3, showing the multi-tube heating tube 4 and angle 5 rotating while the material to be dried R remains inside the main shell 2 shown in Figure 1.

[0060] As shown in Figure 4, when the heating tube 43, angle 5, lifter 51, and feed vane 52 (see Figure 2) rotate, the material to be dried R at the bottom of the main shell 2 is mainly scraped up along the scraping surface 20a by the lifter 51. At this time, the material to be dried R is also scraped up along the scraping surface 20a by the angle 5 and feed vane 52. The amount of material to be dried R that remains in the main shell 2 is usually about 40-50% of the volume of the main shell 2, but this amount can be increased or decreased according to the properties of the material to be dried R and the operating conditions.

[0061] As shown by the dashed arrows in Figure 4, the material to be dried R that is raked up is received by the receiving port 25 formed on the raked surface 20a and sent through the receiving port 25 from the drying space S1 to the crusher internal space S2. At this time, the material to be dried R that has been raked up to the receiving port 25 is guided to the lower surface of the return member 313, making it easier to send it to the crusher internal space S2. Also, when the material to be dried R is being raked up, larger particles of the material to be dried are less likely to fall between the raked surface 20a and the tip of the lifter 51, so the larger the particles, the easier they are to raked up to the receiving port 25. In Figure 4, the parts where large particles of the material to be dried R that are raked up by the angle 5 and lifter 51 make up the majority are shown with cross-hatching. In contrast to the large particles of the material to be dried R, fine particles or powdery material to be dried R tend to spill out from the angle 5 and lifter 51, especially towards the center of the main shell 2, as shown by the dashed arrows in Figure 4.

[0062] The material to be dried R, which is sent into the crusher's internal space S2, is caught between the crushing roller 311 and the inner surface of the crusher shell 310 by the rotation of the crushing roller 311. At least the larger particles are crushed into fine particles or powder with a particle size of generally 5 mm or less. Even particles that are of a certain size but not yet large are also pulverized.

[0063] The material to be dried R, crushed by the crushing roller 311, is blown off the surface of the crushing roller 311 by the air blown out from the outlet 3121, rides onto the subsequent return member 313, and falls from the other end of the return member 313. Most of the fallen material to be dried R is lifted up to near the top by the angle 5, lifter 51, or feed blade 52, or falls directly toward the heating tube 43. In addition, some of the material to be dried R that is scooped up by the angle 5, lifter 51, or feed blade 52, but is not sent from the receiving inlet 25 into the crusher internal space S2, is also lifted up by the angle 5, lifter 51, or feed blade 52 and falls toward the heating tube 43 near the top. In this way, the material to be dried R remaining inside the main shell 2 is dried by the repeated scooping and falling by the angle 5, lifter 51, or feed blade 52. Furthermore, the dried material R, especially the larger particles, is crushed by the crusher 3, becoming fine particles or powder, which fall towards the heating tubes 43. As it falls, it comes into contact with the heating tubes 43 and passes between them, thus accelerating the drying process.

[0064] Figure 5 is a block diagram showing the control configuration of the dryer 1 shown in Figure 1. Although Figure 5 only shows the control configuration that is particularly relevant to this embodiment, the control device 11 performs control over all the components of the dryer 1.

[0065] As shown in Figure 5, the control device 11 controls the driving of the dryer drive motor 27 and the four crusher drive motors 32. The control device 11 also has a load monitoring means 111 that monitors the operating load of the dryer drive motor 27 and the four crusher drive motors 32. This load monitoring means 111 is an example of a monitoring means. The load monitoring means 111 monitors the operating load of each motor based on information on the power value or current value used by each of the dryer drive motor 27 and the four crusher drive motors 32. Furthermore, the control device 11 receives information on the temperature of the material to be dried R inside the main shell 2, as measured by four thermometers 261. The control device 11 also receives information on which of the four thermometers 261 measured the temperature.

[0066] When the temperature of the material to be dried R inside the main shell 2, as measured by the thermometer 261, is below a predetermined temperature (for example, 95 degrees Celsius or below), the control device 11 reduces the rotation speed of the crusher drive motor 32 of the crusher 3 closest to the thermometer 261, or stops the operation of the crusher drive motor 32, thereby reducing the amount of crushing in the crusher 3 (see Figure 1). In this embodiment, since the crushers 3 are positioned directly above each thermometer 261, the control device 11 reduces the rotation speed of the crusher drive motor 32 of the crusher 3 located directly above the thermometer 261 that has measured that the temperature of the material to be dried R is below a predetermined temperature, or stops the operation of that crusher drive motor 32. In other words, the control device 11 controls the operation of the crusher drive motor 32 associated with the thermometer 261 according to the measurement result of the thermometer 261. Note that multiple temperature thresholds may be set, and the rotation speed of the crusher drive motor 32 may be changed according to the temperature of the material to be dried R. For example, the control device 11 may reduce the rotation speed of the crusher drive motor 32 when the temperature falls below a first temperature threshold, and stop the crusher drive motor 32 when the temperature falls below a second temperature threshold which is lower than the first temperature threshold.

[0067] If the temperature of the material to be dried R inside the main shell 2 is below a predetermined temperature, it is assumed that the moisture content of the material to be dried R is too high and the material to be dried R is muddy. Since muddy material to be dried R is unlikely to be crushed by the crusher 3 (see Figure 1), reducing the amount of material to be crushed by the crusher 3 can suppress unnecessary power consumption in the crusher 3. In addition, in the configuration in which the crusher 3 is stopped when the temperature of the material to be dried R is below a predetermined temperature, it is possible to prevent muddy material to be dried R from sticking to the crushing rollers 311 (see Figure 3) and causing problems with the crusher 3.

[0068] Furthermore, the control device 11, when the operating load of the dryer drive motor 27 monitored by the load monitoring means 111 is less than a predetermined load, executes control to reduce the amount of crushing in the crusher 3 (see Figure 1) by lowering the rotational speed of the crusher drive motor 32 or stopping the operation of the crusher drive motor 32. In this case, the control device 11 executes the same control for all four crushers 3, but it may also reduce the amount of crushing for only a specific crusher 3 among the four crushers 3. In addition, multiple load thresholds may be set for the dryer drive motor 27, and the rotational speed of the crusher drive motor 32 may be changed according to the operating load of the dryer drive motor 27. For example, the control device 11 may reduce the rotational speed of the crusher drive motor 32 when it falls below a first load threshold, and stop the crusher drive motor 32 when it falls below a second load threshold which is lower than the first load threshold.

[0069] If the load on the dryer drive motor 27 decreases below a predetermined load, it is assumed that the material R to be dried inside the main shell 2 has not been enlarged. It is also assumed that the material R inside the main shell 2 has a low moisture content, making it difficult for it to enlarge. Therefore, by reducing the amount of crushing performed by the crusher 3, unnecessary power consumption in the crusher 3 can be suppressed.

[0070] Furthermore, the control device 11 may check the load of the crusher drive motor 32 at predetermined time intervals (for example, every few minutes), and if the operating load of the crusher drive motor 32 is less than the predetermined load, it may reduce the rotational speed of the crusher drive motor 32 or stop the operation of the crusher drive motor 32 until the next predetermined time, which is the next check timing, has elapsed, thereby reducing the amount of crushing in the crusher 3 (see Figure 1). After the predetermined time has elapsed since the control device 11 has executed the control to reduce the amount of crushing, it drives the crusher drive motor 32 at the normal rotational speed and checks the load of the crusher drive motor 32. If the operating load of the crusher drive motor 32 is less than the predetermined load, it executes the control to reduce the amount of crushing again until the predetermined time has elapsed. On the other hand, if the operating load of the crusher drive motor 32 is greater than or equal to the predetermined load when the load of the crusher drive motor 32 is checked, it continues to drive the crusher drive motor 32 at the normal rotational speed. The control device 11 then checks the load on the crusher drive motor 32 at predetermined time intervals and controls the operation of the crusher drive motor 32 as described above according to the check results. Preferably, the control device 11 checks the operating load of each of the four crushers 3 and controls the operation of the crusher drive motor 32 by reducing its rotational speed or stopping its operation according to the operating load of each crusher. Alternatively, multiple load thresholds and rotational speeds for each load threshold may be set, and the operating load of the crusher drive motor 32 may be compared with the load thresholds to control the crusher drive motor 32 to a rotational speed corresponding to the operating load.

[0071] Next, we will explain the case where the number of crushers 3 attached to the dryer 1 is reduced. In the following explanation, we will use an example where there is only one crusher 3, but the number of crushers 3 attached to the dryer 1 may be two, three, or more, and of course, as mentioned above, it may be the same number as the receiving inlets 25.

[0072] Figure 6 is a front view showing the dryer 1 shown in Figure 1 with the crusher 3 replaced by a single unit.

[0073] As shown in Figure 6, in this dryer 1, the crusher 3 is attached to the receiving inlet 25, which is the closest to the discharge port among the four receiving inlets 25. The other three receiving inlets 25 are not connected to the crusher 3 and are each closed by a cover plate 28. The cover plate 28 is detachably attached to a mounting part formed on the side of the main body shell 2 by bolts (not shown). Here, the crusher 3 is also detachably attached to a mounting part formed on the side of the main body shell 2, so the crusher 3 can be removed and repositioned to a position where it is connected to another receiving inlet 25. In addition, the receiving inlet 25 in the position where the crusher 3 has been removed can be closed by the cover plate 28. For example, by looking at the state of the material to be dried R inside the main body shell 2 through a viewing window provided in the main body shell 2 and attaching the crusher 3 to the position where the material to be dried R has become the largest particles, the large particles of the material to be dried R can be efficiently crushed. Furthermore, when handling materials R to be dried that are not likely to become large in size, the dryer 1 can be used without attaching the crusher 3 to the main shell 2, by covering all the receiving inlets 25 with the cover plates 28.

[0074] According to the dryer 1 of the embodiment described above, by crushing the material to be dried R inside the main shell 2, it is possible to suppress the accumulation of material to be dried R that has been enlarged and whose drying has not been promoted by this process. Moreover, since the enlarged material to be dried R is more easily scooped up to the receiving port 25 by the lifter 51 than the small particles or powdered material to be dried R, the crusher 3 connected to the receiving port 25 can efficiently crush the enlarged material to be dried R. Furthermore, by crushing the enlarged material with the crusher 3, the surface area of ​​the material to be dried R inside the main shell 2 increases, thereby improving drying efficiency. In addition, the crusher 3 can also crush the material to be dried R before it becomes enlarged, making it less likely for the material to become enlarged. As a result, the amount of bed material (dried product) that is initially put into the main shell 2 can be reduced. Furthermore, since the accumulation of the enlarged material to be dried R within the main shell 2 is suppressed, the complicated process of stopping the dryer, removing the material from the main shell 2, adding new bed material, and then restarting operation is eliminated. In addition, there is no need to reduce the amount of material to be dried R added to the main shell 2 in order to accelerate the drying of the enlarged material to be dried R and reduce the amount of material to be dried R that accumulates within the main shell 2.

[0075] Next, a modified example of this embodiment will be described. In the following description, components with the same names as those described so far will be given the same reference numerals as those used so far, and redundant explanations may be omitted.

[0076] Figure 7(a) shows a first modified example of the lifter 51 shown in Figure 3. In Figures 7(a) to (c), the lifter 51 viewed axially from the discharge port side is shown on the left side of the figure, and its right side view is shown on the right side. Also, in Figures 7(a) to (c), the upper side of the figure is the tip side of the lifter 51, and the lower side of the figure is the base side of the lifter 51.

[0077] As shown in Figure 7(a), the lifter 51 of the first modified example differs from the lifter 51 shown in Figure 3 in that the tip portion of the lifter 51 is comb-shaped, consisting of multiple protrusions 51a and multiple recesses 51b. The spacing L1 between the blades in this comb-shaped blade is set to be approximately the same as the maximum diameter allowed for the desired dried material D (see Figure 1). In this first modified example, the lifter 51 mainly scoops up the dried material R (see Figure 4) with particles larger than the spacing L1 between the comb blades, so that the dried material R that has been granulated to a size larger than the size to be crushed can be selectively sent into the crusher space S2 by the lifter 51. As a result, the dried material R that has been granulated to the size to be crushed can be efficiently crushed by the crusher 3.

[0078] Figure 7(b) shows a second modified example of the lifter 51 shown in Figure 3.

[0079] As shown in Figure 7(b), the lifter 51 of the second modified example differs from the lifter 51 shown in Figure 3 in that the lifter 51 is composed of a mesh having multiple holes. The vertical and horizontal width L2 of the holes in this mesh is set to be approximately the same as the maximum diameter allowed for the desired dried material D (see Figure 1). In this second modified example, as in the first modified example, the dried material R, which has been granulated to the size to be crushed, can be efficiently crushed by the crusher 3.

[0080] Figure 7(c) shows a third modified example of the lifter 51 shown in Figure 3.

[0081] As shown in Figure 7(c), the lifter 51 of the third modified example differs from the lifter 51 shown in Figure 3 in that a plurality of holes 51c are formed on the tip side of the lifter 51. The diameter L3 of these holes 51c is set to be approximately the same as the maximum diameter allowed for the desired dried material D (see Figure 1). In this third modified example, as in the first and second modified examples, the dried material R, which has been granulated to the size to be crushed, can be efficiently crushed by the crusher 3.

[0082] Figure 8 is an enlarged cross-sectional view showing a modified example of the return member 313 shown in Figure 3.

[0083] As shown in Figure 8, in this modified example, the return member 313 is provided with a hinge 3131 at the point where it intersects with the receiving port 25, and the other end portion 313a of the return member 313 is configured to rotate around the hinge 3131 as the pivot point. Furthermore, by being rotated by an actuator such as a solenoid (not shown) controlled by the control device 11 (see Figure 5), the other end portion 313a changes angle between a first angular position protruding into the drying space S1 and a second angular position facing downwards. In the second angular position, the other end portion 313a acts as a lid that closes the lower part of the receiving port 25. In Figure 8, the other end portion 313a in the first angular position is shown by a dashed line, and the other end portion 313a in the second angular position is shown by a solid line.

[0084] According to this modified return member 313, the lower part of the receiving port 25 is blocked by the other end portion 313a at the second angular position, thereby preventing the material to be dried R from entering the crusher internal space S2. Therefore, if the temperature of the material to be dried R exceeds a predetermined temperature, the other end portion 313a is set to the first angular position, and if the temperature of the material to be dried R is below the predetermined temperature, it is set to the second angular position, thereby preventing the muddy material to be dried R from entering the crusher internal space S2. This prevents the muddy material to be dried R from sticking to the crushing rollers 311 and other parts, which could cause problems in the crusher 3.

[0085] The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the claims. For example, in the embodiments described above, the crusher 3 crushes the material to be dried R between a single crushing roller 311 and the inner surface of the crusher shell 310, but any method that can crush the material to be dried R is acceptable, such as a method in which the material to be dried is jammed between two crushing rollers 311. Of course, by adopting a method of crushing with a single crushing roller 311 as in this embodiment, the crusher 3 can be given the function of transporting the crushed material to be dried R by the crushing roller 311 and returning it to the drying space S1 at low cost. In addition, the lifters 51 may be arranged in a line around the entire circumference in the rotational direction at predetermined intervals in the axial direction, or they may be arranged in a spiral shape with the receiving inlet 25 provided around the entire circumference in the rotational direction. Furthermore, the return member 313 does not have to extend to the drying space S1 at its other end. Furthermore, to allow adjustment of the position of the other end of the return member 313, the return member 313 may be composed of at least two separate members, one at one end and the other at the other end, and the other end may be configured to slide relative to the one end.

[0086] Furthermore, even if a constituent element is included only in the description of each of the modified examples described above, that constituent element may be applied to other modified examples as well. [Explanation of Symbols]

[0087] 1 Dryer 2 Main shell 3. Crusher 20 Inner surface 25 Inlet 43 Heating tube 51 Lifter O Rotation axis R Material to be dried

Claims

1. A cylindrical body shell, The aforementioned main body shell is provided with a plurality of heating tubes that are spaced apart from each other, rotate around a rotation axis, and dry the material to be dried by coming into contact with the material to be dried placed inside the main body shell, A lifter that rotates together with the heating tube within the main body shell and scrapes up the material to be dried along the inner surface of the main body shell, The system includes a crusher for crushing the material to be dried, The main shell is formed with an opening for receiving the material to be dried, which has been scraped up by the lifter. The dryer is characterized in that the crusher is connected to the receiving port.

2. The dryer according to claim 1, characterized in that the crusher is detachably attached to the main body shell.

3. The dryer according to claim 2, characterized in that the main body shell has a plurality of receiving openings formed at intervals along the axial direction of the rotation shaft.

4. The main body shell has multiple input ports formed along the axial direction at intervals from each other, into which the material to be dried is introduced. The dryer according to claim 3, characterized in that the receiving port is formed at a position that overlaps with the input port in the axial direction.

5. The dryer according to claim 1, characterized in that the lifter has a comb-like or multiple holes formed therein.

6. A thermometer for measuring the temperature of the object to be dried inside the main body shell, The system includes a control device for controlling the crusher, The dryer according to any one of claims 1 to 5, characterized in that the control device performs control to reduce the amount of crushing in the crusher when the temperature measured by the thermometer is below a predetermined temperature.

7. An actuator for rotating the heating tube and the lifter, A monitoring means for monitoring the operating load of the actuator, The system includes a control device for controlling the crusher, The dryer according to any one of claims 1 to 5, characterized in that the control device performs control to reduce the amount of crushing in the crusher when the operating load monitored by the monitoring means is less than a predetermined load.

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