JP6856832B2 - Dryer - Google Patents

Description

The present invention relates to a dryer that dries the object to be dried by bringing the object to be dried into the main body shell from the charging port into contact with a multi-tube heating tube rotating in the main body shell.

Wastewater treatment A dryer that dries sludge and other objects to be dried in the process of recycling or reducing the volume of sludge, animal and plant residues, food residues, muddy waste, etc., or chemical products such as resins, medical doctors. As a dryer for agricultural chemicals, foods, etc., a dryer having a main body shell and a multi-tube heating tube rotating in the main body shell is known. In this dryer, the multi-tube heating tube is heated by flowing saturated steam or the like into the multi-tube heating tube, and the object to be dried is brought into contact with the heated multi-tube heating tube to make the object to be dried. It is a conduction heat transfer type that transfers heat.

The main body shell is provided with an input port for charging the dried material and a discharge port for discharging the dried material, and the charged material stays in the main body shell between the charging port and the discharge port. During the period, it is dried. The main body shell is installed on the machine frame or the like in a horizontal direction or in a state of extending slightly downward from the inlet side to the outlet side. The multi-tube heating tube has a tube bundle in which a plurality of heating tubes are arranged at predetermined intervals from each other. This tube bundle is rotatably arranged in the main body shell around a rotation axis along the extending direction of the main body shell. Further, the multi-tube heating tube includes a frame member (for example, an angle) that also reinforces the multi-tube heating tube as a scraping member that scrapes up the object to be dried that stays in the main body shell when rotating, and this frame. A lifter and a feed vane that can be attached to the member are provided.

In such a dryer, the object to be dried charged from the charging port is scraped up by the scraping member of the rotating multi-tube heating tube, and when it falls, it comes into contact with each heating tube to be dried. Moisture evaporates from, and the object to be dried dries. That is, the outer peripheral surface of each heating tube becomes a heat transfer surface that transfers heat to the object to be dried. In addition, the object to be dried can be dried by stirring the object to be dried as the multi-tube heating tube rotates. The object to be dried gradually moves to the discharge port side while the water content decreases as the contact and stirring with each heating tube are repeated, and eventually the dried product is discharged from the discharge port.

Here, when the object to be dried is an amorphous grain and has a small bulk specific gravity, it is liable to be entangled and crushed to form a lump. In particular, the object to be dried that has just been charged from the inlet and has a high water content may be held between the scraping members such as angles and may be bridged between the scraping members as a lump. .. Hereinafter, a mass in which the object to be dried is held between the scraping member and the scraping member (in a state of being bridged) may be referred to as a bridge. Further, even when a fibrous material or a highly viscous material is used as the object to be dried, bridging is likely to occur particularly in a state where the water content is high and the dispersibility is poor, which is just added from the inlet.

When a bridge is formed between the scraping member and the scraping member, this bridge prevents the inflow of the object to be dried to the heating tube side arranged inside the scraping member, and heats the object to be dried. Insufficient contact with the tube. As a result, the area of the heat transfer surface that comes into contact with the object to be dried is reduced, and as a result, the capacity of the dryer is reduced (the expected amount of water evaporation cannot be obtained), so that the amount of processing is reduced. There is. If the operation of the dryer is continued with the bridge formed, the bridge is gradually hardened by the pressure, and the work of removing the bridge becomes difficult.

Here, in order to prevent the occurrence of a bridge, the input of the material to be dried may be controlled by intermittently charging the material to be dried from the charging port to adjust the amount of the material to be dried in the main body shell. However, such control tends to be complicated and is not preferable. Further, if an attempt is made to suppress the occurrence of a bridge by reducing the amount of the object to be dried in the main body shell, the residence (drying) time is reduced and the drying ability is lowered. Alternatively, in order to reduce the amount of retention to obtain a dried product having a predetermined water content, the size of the dryer has to be increased. Therefore, a dryer has been proposed that attempts to prevent the formation of bridges by lowering the water content of the object to be dried in the vicinity of the inlet (see, for example, Patent Document 1 and the like).

The dryer described in Patent Document 1 is provided with an outlet on the discharge port side of the main body shell and a return port on the inlet side of the main body shell, and a screw conveyor is arranged between the outlet and the return port. There is. In this dryer, a part of the dried product that has moved to the discharge port side is received by the outlet, is conveyed by the screw conveyor, and is returned from the return port to the input port side in the main body shell. As a result, the dried product is mixed with the material to be dried having a high water content on the inlet side, and the apparent water content of the product to be dried on the input port side is reduced. As a result, the dispersibility of the object to be dried on the input port side is improved, and the generation of the bridge is prevented without controlling the input of the object to be dried and without reducing the amount of the material to be dried. It is a thing.

Japanese Unexamined Patent Publication No. 2006-17335

However, in the dryer described in Patent Document 1, although it is possible to suppress the occurrence of bridging to some extent by lowering the water content of the object to be dried, once the bridging has occurred, it can be suppressed. There is no means to eliminate it, and there is room for improvement in ensuring contact between the heating tube and the object to be dried.

In view of the above circumstances, it is an object of the present invention to provide a dryer capable of preventing a decrease in drying ability by breaking the bridge and ensuring contact between the heating tube and the object to be dried.

The dryer of the present invention that solves the above object has a main body shell into which an object to be dried is charged and a main body shell.
A multi-tube heating tube that rotates around a rotation axis in the main body shell is provided.
The multi-tube heating tube has a plurality of heating tubes extending along the rotation axis outside the rotation axis, and an air purge tube.
The plurality of heating tubes are arranged at intervals from each other, and dry the object to be dried by coming into contact with the object to be dried put into the shell of the main body.
The air purge pipe is arranged on a virtual line connecting the outermost heating pipes among the plurality of heating pipes with a straight line in the rotation direction or outside the virtual line, and is centered on the rotation axis. It is characterized by having an outlet for blowing off a bridge generated outside the air purge pipe by blowing out gas from the side to the outside.

Here, the outlet may be a round hole, a slit extending in the direction of the rotation axis, or a nozzle-shaped outlet.

According to the dryer of the present invention, even if a bridge is formed between the scraping members located outside the plurality of heating pipes, the bridge is blown off by blowing gas from the outlet of the air purge pipe. Can be broken. As a result, the inflow of the object to be dried to the heating tube side is not obstructed by the bridge, and the contact between the heating tube and the object to be dried is ensured. As a result, it is possible to prevent a decrease in drying ability.

Here, the bridge is used when the scraping member passes through the object to be dried retained in the main body shell by the rotation of the multi-tube heating tube while pressing the object to be dried by the scraping member. In many cases, it is presumed that this is due to the situation where the compression force is applied from the inner wall side of the main body shell toward the center side of the rotating shaft of the multi-tube heating tube. In the dryer of the present invention, since the gas is blown out from the outlet toward the outside opposite to the direction in which the compressive force is presumed to be applied to the bridge, the bridge can be blown off efficiently. Further, since the gas can be blown from the outlet immediately after the bridge is formed, it is possible to adopt a mode in which the bridge is broken before it is firmly fixed. Of course, it is possible not only to break the bridge that has been formed, but also to perform an operation aiming at a preventive effect of blowing off the object to be dried adhering to the scraping member before forming the bridge.

Furthermore, since the air purge pipe is arranged on the virtual line or outside the virtual line and the air outlet blows out gas toward the outside of the virtual line, the gas blown out from the air outlet is heated. There is little risk of contact with the pipe. Therefore, even when the temperature of the gas blown out from the outlet is low, the inconvenience of losing the amount of heat such as saturated steam that comes into contact with the heating pipe and heats the heating pipe is unlikely to occur.

Further, in the dryer of the present invention, the multi-tube heating tube is provided outside the air purge tube at intervals in the rotation direction, and scrapes up the object to be dried in the main body shell. It has a scraping member of
It is preferable that the air purge pipe blows gas from the outlet toward the space between the plurality of scraping members.

The scraping member referred to here may be a frame (for example, an angle) extending in the rotation axis direction like the heating tube and also serving as reinforcement of the multi-tube heating tube. Further, the scraping member may include lifters and feed vanes provided at intervals in the extending direction of the frame. In this aspect, the lifter, the feed blade, and the frame that also functions as the lifter and the mounting seat of the feed blade correspond to the scraping member.

Further, in the dryer of the present invention, the outlet may blow out gas toward the upstream side in the rotation direction.

By doing so, when the air purge pipe is also rotated by the rotation of the multi-tube heating pipe, it becomes difficult for the object to be dried staying in the main body shell to enter the air purge pipe from the air outlet.

Further, in the dryer of the present invention, the air purge pipe may be provided with a plurality of the air outlets at intervals in the direction of the rotation axis.

By doing so, it is possible to efficiently break the bridge generated when the object to be dried staying in the main body shell moves in the direction of the rotation axis.

Further, in the dryer of the present invention, the main body shell is provided with a charging port provided on one side in the rotation axis direction for charging the object to be dried, and the dried product to which the object to be dried is dried is discharged. It has a discharge port provided on the other side in the direction of the rotation axis.
One of the preferred embodiments is a configuration in which the outlet is provided at a position closer to the inlet than the outlet.

As described above, the object to be dried that stays in the main body shell is more likely to be bridged when it has just been charged from the inlet and has a high water content. Therefore, by providing the outlet at a position closer to the inlet than the outlet, the gas supplied to the air purge pipe is concentrated on the inlet side where a bridge is likely to occur, and the bridge is further formed. It can be broken efficiently.

Further, in the dryer of the present invention, the main body shell has an exhaust port for discharging steam evaporated from the object to be dried together with carrier air supplied into the main body shell.
A supply path for supplying the gas discharged from the exhaust port to the air purge pipe may be provided between the exhaust port and the air purge pipe.

By doing so, the gas discharged from the exhaust port can be used as the gas blown out from the outlet. A path is also provided between the carrier air port for introducing carrier air into the main body shell and the exhaust port, and the gas discharged from the exhaust port is supplied to the main body shell as carrier air. You may.

According to the present invention, it is possible to provide a dryer capable of preventing a decrease in drying ability by breaking the bridge and ensuring contact between the heating tube and the object to be dried.

It is a block diagram which shows an example of the dryer corresponding to one Embodiment of this invention. FIG. 1A is a diagram schematically showing a cross section of the multi-tube heating tube shown in FIG. 1, and FIG. 1B is a diagram showing a modified example in which the configuration of the air purge tube shown in FIG. 1 is different. FIG. 5 is a cross-sectional view taken along the line AA of the dryer shown in FIG. (A) is an enlarged view showing the part C surrounded by a circle in FIG. 3, and (b) and (c) are views showing a modified example of the air purge pipe shown in (a). It is a figure which conceptually shows the estimated state until a bridge occurs. (A) is a figure which shows the aspect corresponding to FIG. 3 in the dryer of 2nd Embodiment of this invention, and (b) is with respect to the dryer of 2nd Embodiment shown in (a). , It is a figure which shows the modification which changed the arrangement of the air purge pipe. It is a figure which shows the aspect corresponding to FIG. 2 in the dryer of 3rd Embodiment of this invention. It is a figure which shows the aspect corresponding to FIG. 1 in the dryer of 4th Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The dryer according to the embodiment of the present invention is a drying treatment for recycling or reducing the volume of wastewater treatment sludge, animal and plant residues, food residues or muddy waste, or a chemical product such as a resin. It is used to dry medical and agricultural chemicals, foods, etc., and the object to be dried is not particularly limited.

FIG. 1 is a block diagram showing an example of a dryer corresponding to an embodiment of the present invention.

As shown in FIG. 1, the dryer 1 includes a main body shell 2, a multi-tube heating tube 3 arranged in the main body shell 2, and an exhaust path 4. The main body shell 2 is supported in a horizontally extending state by a machine frame or the like (not shown). The direction in which the main body shell 2 extends coincides with the direction of the rotation axis of the multi-tube heating tube 3 as described in detail later, and hereinafter, the direction of the rotation axis of the multi-tube heating tube 3 (main body shell 2). Extending direction) may be referred to as the rotation axis direction.

The main body shell 2 is provided with an inlet 21, an outlet 22, a carrier air port 23, an exhaust port 24, and a second carrier air port 25. The charging port 21 is a port for charging the object R to be dried, which is closer to the right side of the main body shell 2 shown in FIG. 1, and is provided, for example, at the upper end portion of the main body shell 2. A plurality of input ports 21 may be provided at predetermined intervals in the direction of the rotation axis. The water content of the discharge port 22 is lowered by performing a drying treatment described later while the object to be dried R (see FIG. 3) charged from the charging port 21 stays in the main body shell 2. , An opening that is discharged as a dried product D. The discharge port 22 is closer to the left side of the main body shell 2 shown in FIG. 1 and is provided on the side surface of the main body shell 2 (in FIG. 1, the side surface of the main body shell 2 on the back side of the paper surface). The discharge port 22 is provided with a weir member 221 whose height can be adjusted, and the height of the lower end position of the opening portion of the discharge port 22 can be adjusted by adjusting the height of the weir member 221. .. By this adjustment, the amount of the object to be dried R staying in the main body shell 2 can be adjusted. Further, a chute 222 is arranged in a portion of the main body shell 2 where the discharge port 22 is provided. The object to be dried R charged from the charging port 21 moves from the right side to the left side in the main body shell 2 shown in FIG. 1, and is eventually discharged from the discharging port 22. In the main body shell 2 shown in FIG. 1, the right side is the inlet side and the left side is the outlet side. That is, the inlet side (right side) corresponds to one side, and the discharge port side (left side) corresponds to the other side. The main body shell 2 may be installed on the machine frame or the like in a state of extending slightly downward from the inlet side toward the outlet side.

The carrier air port 23 is a port for introducing carrier air sent by the supply blower 51 and heated to, for example, about 120 ° C. by the heater 52 into the main body shell 2. The exhaust port 24 is a port for discharging the vapor evaporated from the object to be dried R to the outside of the main body shell 2 together with the carrier air introduced from the carrier air port 23. The carrier air introduced into the main body shell 2 from the carrier air port 23 flows on the upper side in the main body shell 2 which is the surface layer portion of the object to be dried R staying in the main body shell 2, and evaporates from the object to be dried R. It is discharged from the exhaust port 24 together with the steam.

The exhaust path 4 connected to the exhaust port 24 is provided with a dust collector 41 and an exhaust blower 42, and the gas discharged from the exhaust port 24, that is, steam and carrier air (hereinafter, these are collectively referred to as exhaust air). (Sometimes referred to as) is sent to the dust collector 41, and after performing a predetermined process such as removal of fine powder, it is exhausted to the outside through an exhaust blower 42. Further, a part of the exhaust air exhausted through the exhaust blower 42 is introduced into the main body shell 2 from the second carrier air port 25 as carrier air.

The multi-tube heating tube 3 is rotatably arranged in the main body shell 2 around a rotating shaft. Hollow shafts 31 are provided at both ends of the rotating shaft, and a rotary joint is provided on the hollow shaft 31. 32 is provided. The hollow shaft 31 is pivotally supported by a bearing (not shown) and rotated by a motor (not shown) or the like to rotate the multi-tube heating tube 3.

The multi-tube heating tube 3 includes a tube bundle 33. The tube bundle 33 is a bundle of a plurality of heating tubes 331 and a plurality of air purge tubes 332 arranged along the rotation axis. Although the air purge pipe 332 is hatched in FIG. 1, the details of the arrangement of the heating pipe 331 and the air purge pipe 332 will be described later. Saturated steam introduced from the rotary joint 32 on the discharge port side is supplied to the plurality of heating pipes 331. The gas purge pipes 332 are heated to, for example, about 100 ° C. by a heater (not shown) or the like, and gas introduced from the rotary joint 32 on the inlet side is supplied by a blower (not shown). Hereinafter, the gas supplied to the air purge pipe 332 may be referred to as blown air.

A disk-shaped input port side header 35 is provided at the end portion of the tube bundle 33 on the input port side. In FIG. 1, the discharge port side is hidden because the outer surface of the main body shell 2 is drawn, but the disk-shaped discharge port side header 36 (see FIG. 2) is located at the end portion of the tube bundle 33 on the discharge port side. ) Is provided. A plurality of angles 371 made of, for example, equilateral angle steel are bridged between the pair of headers 35 and 36 at predetermined intervals in the rotation direction of the multi-tube heating tube 3. The distance between the plurality of angles 371 in the rotation direction is not particularly limited, but is provided at a pitch of, for example, about 300 mm. Further, the angle 371 is provided with a plurality of steel plate lifters 372 and feed vanes 373 at predetermined intervals in the direction of the rotation axis.

The angle 371 is a frame that reinforces the multi-tube heating tube 3, and also has a function of a mounting seat for the lifter 372 and the feed blade 373. When the multi-tube heating tube 3 rotates, it stays in the main body shell 2 to be dried. It scrapes up the object R. The lifter 372 scrapes up the object to be dried R that stays in the main body shell 2 when the multi-tube heating tube 3 rotates. When the multi-tube heating tube 3 rotates, the feed blade 373 sends the object to be dried R staying in the main body shell 2 to the discharge port side while scraping it up. That is, in the present embodiment, the angle 371, the lifter 372, and the feed vane 373 correspond to an example of the scraping member.

FIG. 2A is a diagram schematically showing a cross section of the multi-tube heating tube shown in FIG. In FIG. 2A, the angle 371, the lifter 372, and the feed vane 373 are omitted in order to simplify the drawing. Further, the air purge pipe 332 shows one of the uppermost ones among the plurality.

As shown in FIG. 2A, the input port side header 35 and the discharge port side header 36 are hollow. Further, the input port side header 35 is partitioned by a partition wall 351 and has a first space S communicating with the hollow shaft 31 and a second space V located on the discharge port side with the first space S and the partition wall 351 separated from each other. And are formed.

In each of the plurality of heating pipes 331, the end portion on the discharge port side enters the discharge port side header 36, and the end portion on the inlet side thereof enters the second space V of the input port side header 35. As a result, the inside of the discharge port side header 36 and the inside of the second space V of the input port side header 35 communicate with each other via the heating pipe 331. Further, the air purge pipe 332 is fixed to the discharge port side header 36 in a state where the end portion on the discharge port side is closed, and the end portion on the inlet side penetrates the partition wall 351 and the first of the inlet side header 35. It is in one space S. As a result, the air purge pipe 332 communicates with the inside of the first space S of the input port side header 35. The heating pipe 331 and the air purge pipe 332 are supported by a plurality of support plates 39 arranged at predetermined intervals in the rotation axis direction. Each of the plurality of support plates 39 has a plurality of through holes through which the heating pipe 331 and the air purge pipe 332 penetrate in the rotation axis direction. Further, the discharge port side header 36 is provided with a siphon type drainage device 38.

When saturated steam is supplied from the rotary joint 32 on the discharge port side, the saturated steam passes from the discharge port side header 36 through a plurality of heating pipes 331 as shown by the white arrows in FIG. 2, and the input port side header 35 Reach the second space V of. As a result, the heating tube 331 is maintained in a state of being heated to a substantially constant temperature in the direction of the rotation axis. The drain generated by condensing the saturated steam in the heating pipe 331 flows generally toward the inlet side and collects on the bottom side of the inlet side header 35 in the second space V. As the amount of drain accumulated in the second space V increases, as shown by the dotted arrow in FIG. 2, it eventually flows toward the discharge port side through the heating pipe 331 located at the lower part in the figure. It collects on the bottom side in the discharge port side header 36. The drain collected in the discharge port side header 36 is discharged from the multi-tube heating pipe 3 by the drain device 38.

When blown air is supplied from the rotary joint 32 on the inlet side, this blown air flows through the air purge pipe 332 from the first space S of the header 35 on the inlet side as shown by the solid arrow in FIG. 2, and a plurality of blown airs are blown. It is blown out from the outlet 332a toward the outside. In the present embodiment, three outlets 332a are provided on the inlet side of the air purge pipe 332 at intervals in the direction of the rotation axis. The number of the outlets 332a is not particularly limited, and may be provided at the same position in the rotation axis direction in the plurality of air purge pipes 332, or may be provided at different positions in the rotation axis direction for each air purge pipe 332. You can also do it.

FIG. 2B is a diagram showing a modified example in which the configuration of the air purge pipe 332 shown in FIG. 2A is different.

As shown in FIG. 2B, the air purge pipe 332 of the modified example has the inlet side header 35 having its end portion on the inlet side penetrates the partition wall 351 like the air purge pipe 332 shown in FIG. 2A. However, the length in the direction of the rotation axis is shortened according to the range in which the required plurality of outlets 332a are formed. Further, in the modified example of the air purge pipe 332, the end portion on the discharge port side is supported by the support plate 39, and the end portion on the discharge port side is closed by the cap 332b.

As described above, the air purge pipe 332 is not limited to the length for connecting the discharge port side header 36 and the input port side header 35. That is, the air purge pipe 332 does not necessarily have to be connected from the inlet side header 35 to the discharge port side header 36, and has a length corresponding to a plurality of outlets 332a as in the modified example shown in FIG. 2 (b). It is also possible to adopt the above and support the end portion on the discharge port side by the support plate 39.

FIG. 3 is a cross-sectional view taken along the line AA of the dryer shown in FIG. 1, schematically showing the arrangement of the heating pipe 331 and the air purge pipe 332. Further, in FIG. 3, in order to distinguish between the heating pipe 331 and the air purge pipe 332, the heating pipe 331 is shown by an unfilled circle, and the air purge pipe 332 is hatched.

As shown in FIG. 3, the main body shell 2 is a hollow member having a substantially elliptical cross section. In FIG. 3, the virtual rotation axis is indicated by O, and in FIG. 3, as shown by the thick curved arrow, the multi-tube heating tube 3 is rotated clockwise around the rotation axis O. It is a view. Further, an discharge port 22 (see FIG. 1) (not shown) is provided on the left side surface of the main body shell 2 in the figure.

In the present embodiment, stainless steel pipes having a nominal diameter of 50 A are used for the heating pipe 331 and the air purge pipe 332. The plurality of heating tubes 331 are arranged in a plurality of rows in a regular hexagonal shape centered on the rotation axis O. Further, the heating pipe 331 arranged on the outermost side is arranged in a regular hexagonal shape with an air purge pipe 332 in between. In the figure, a virtual line L connecting the heating pipes 331 arranged on the outermost side with a straight line with respect to the center point is shown by a dotted line. In the present embodiment, the air purge pipe 332 is a virtual line having a regular hexagonal shape. It is arranged on L. Although only one location is shown outside the virtual line L as an example, the air purge pipe 332 may be arranged as shown by the alternate long and short dash line circle.

In FIG. 3, the object to be dried R is charged from the charging port 21, and an amount of the object to be dried R that fills about half of the number of heating tubes 331 constituting the multi-tube heating tube 3 stays in the main body shell 2. The approximate position of the surface in the state of being in the state is shown by a solid line. The amount of retention may be increased or decreased according to the physical properties of the object to be dried and the operating conditions. The object to be dried R staying in the main body shell 2 is scraped up by the angle 371, the lifter 372, and the feed blade (not shown in FIG. 3) by rotating the multi-tube heating tube 3. By repeating the scraping by the angle 371 and the like, the object to be dried R staying in the main body shell 2 is deposited in a state of gradually increasing from the right side to the left side in FIG. Between the angle 371 and the angle 371 from when the multi-tube heating tube 3 rotates and slips into the object to be dried R in which the angle 371 and the like are retained until it comes out from the object to be dried R in which the angle 371 and the like are retained. , A compressive force may be generated on the object to be dried R located between the lifter 372 and the lifter 372, or between the feed blade 373 (see FIG. 1) and the feed blade 373, and a bridge B may be generated. Therefore, as shown by a straight arrow in the figure, blown air is blown from the air purge pipe 332 between the scraping members such as the angle 371, and the bridge B is blown off to break it.

FIG. 4A is an enlarged view showing a portion C surrounded by a circle in FIG.

As shown in FIG. 4A, the air purge pipe 332 has a large number of air purge pipes 332 that connect the rotation center of the rotation axis O and the center of the air purge pipe 332 toward the upstream side in the rotation direction indicated by the arcuate arrow in the figure. An outlet 332a is formed to blow out the blown air (directed to the upstream side in the rotation direction with respect to the normal line to the rotation circle formed by the tubular heating tube 3). The air outlet 332a is formed of a round hole having an opening toward the upstream side in the rotation direction, for example, about 1 mm to 3 mm. Therefore, as shown in FIG. 3, even if the air purge pipe 332 slips into the object to be dried R staying in the main body shell 2 due to the rotation of the multi-tube heating tube 3, the object to be dried from the outlet 332a. It is difficult for R to enter the air purge pipe 332.

In the present embodiment, the air outlet 332a is formed by a round hole, but the air outlet 332a may be formed by a slit extending in the rotation axis direction. Further, as shown in FIG. 4B, a hole 3321 may be formed in the air purge pipe 332 and a hook-shaped first nozzle 3322 may be provided to form an outlet 332a. Further, as shown in FIG. 4C, a trumpet-shaped second nozzle 3323 may be provided in the air purge pipe 332, and the outlet 332a may be formed by the second nozzle 3323. In addition, as shown by the arrow in the figure, the blown air may be blown out in a fan shape from the blowout port 332a formed by the second nozzle 3323.

Next, the drying process using the dryer 1 of the present embodiment will be described with reference to FIGS. 1, 2 (a), 3 and 4 (a).

First, after starting the exhaust blower 42, the dust collector 41 is also started, and then, for example, carrier air heated to about 120 ° C. is supplied from the carrier air port 23, and blown air heated to, for example, about 100 ° C. is supplied. Is supplied to the rotary joint 32 on the inlet side, and subsequently, the multi-tube heating tube 3 is rotated. After that, saturated steam of, for example, about 150 ° C. is supplied to the rotary joint 32 on the discharge port side. The supplied saturated steam is also supplied to each heating pipe 331 from the discharge port side header 36 shown in FIG. 2A, whereby each heating pipe 331 is heated. Next, the object to be dried R is charged into the main body shell 2 from the charging port 21. In the present embodiment, the blown air is supplied before the object to be dried is put into the main body shell 2, and the blown air is blown out from the outlet 332a of the air purge pipe 332, so that the object R to be dried enters the air purge pipe 332. It is preventing that.

The object to be dried R thrown into the main body shell 2 is agitated by being scraped up by the angle 371, the lifter 372 and the feed vane 373 by the rotation of the multi-tube heating tube 3, and is stirred with the heating tube 331. Receives heat by contact. When the multi-tube heating tube 3 rotates and passes through the retained object R to be dried, a bridge B may be formed between the scraping members such as the angle 371 as shown in FIG. In the dryer 1 of the present invention, the bridge B can be blown off and broken by blowing out the blown air from the air purge pipe 332. As a result, the inflow of the object to be dried R into the heating tube 331 is not obstructed by the bridge B, and the contact between the heating tube 331 and the object to be dried R is ensured. As a result, it is possible to prevent a decrease in drying ability.

FIG. 5 is a diagram conceptually showing a presumed state until the bridge is formed. In FIG. 5, the lifter immediately after sneaking into the object to be dried R staying in the main body shell 2 is designated by the reference numeral 372a, and the lifter arranged from the lifter 372a in the rotation direction is referred to. The symbols 372b to 372g are attached in order. The lifter 372f and the lifter 372g are located above the retention portion of the object to be dried R.

It is presumed that the lifter 372a immediately after sneaking into the object R to be dried proceeds while pressing the object R to be dried, and the object R to be dried pressed by the lifter 372a is compressed to generate deposits b. The deposit b can also be understood as a portion that is pressed and compacted.

In the lifter 372b to the lifter 372d that have advanced in the object to be dried R, the deposit b gradually grows and becomes larger. When exposed from the retained object R to be dried, the fragile portion of the deposit b in the deposit b collapses due to its own weight, but there is a portion that remains without collapsing, and these are repeated by rotating the multi-tube heating tube 3. Eventually, as shown between the lifter 372e and the lifter 372f, or between the lifter 372f and the lifter 372g, it is presumed that a bridge B bridged between the lifter 372 is formed.

Further, as shown in an enlarged circle, it is presumed that the deposit b pressed against the lifter 372 will have a wider range of consolidation in the plane direction of the lifter 372, which is indicated by the double-headed arrow in the figure. Of the directions spreading here, the direction (outside) of the inner wall 2a of the main body shell 2 is pressed by the inner wall 2a and compacted. As a result, it is presumed that the outer portion b2 (the portion indicated by the dark shading) on the inner wall 2a side becomes hard and does not easily collapse. On the other hand, although there is a heating pipe 331 and an air purge pipe 332 in the rotation axis O direction (inside), since there is a distance from the inner wall 2a, it swells without being blocked. As a result, it is presumed that the inner portion b1 (the portion indicated by the thin shading) on the rotation shaft O side has a smaller degree of consolidation than the outer portion b2 and is soft and brittle.

In the present embodiment, the direction of the compressive force applied to the bridge B, which is presumed to be from the outside to the inside (rotation center side) of the scraping member, is directed to the outside, that is, relatively opposite to the direction shown in FIG. Since the blown air is blown toward the inner portion b1 which is presumed to be soft and brittle, the bridge B can be blown off efficiently. Further, as described above, the generated bridge B becomes harder by being compressed and repeatedly compacted by sneaking into the object to be dried R staying in the main body shell 2 as the multi-tube heating tube 3 rotates. However, since the blown air can be blown when the generated bridge B is exposed from the object to be dried R staying in the main body shell 2, the bridge B can be broken before it becomes hard.

Furthermore, the air purge pipe 332 is arranged on the virtual line L or outside the virtual line L as shown by the alternate long and short dash line L in FIG. 3, and the outlet 332a (see FIG. 4) is located outside the virtual line L. Since the blown air is blown toward the heating pipe 331, there is little possibility that the blown air will come into contact with the heating pipe 331. Therefore, even if the temperature of the blown air is, for example, about 100 ° C., the inconvenience of losing the heat amount of the saturated steam, for example, about 150 ° C., which contacts the heating pipe 331 and heats the heating pipe 331, is unlikely to occur.

Furthermore, while sneaking into the object to be dried R staying in the main body shell 2, the outlet 332a of the air purge pipe 332 is blocked by the object to be dried R, and the blown air is less likely to be blown out. Therefore, the blown air is concentratedly blown out from the air purge pipe 332 located above the object to be dried R staying in the main body shell 2, and the bridge B can be blown off more efficiently.

Further, as shown in FIG. 2, a plurality of outlets 332a of the present embodiment are provided at intervals in the rotation axis direction on the inlet side. As a result, the bridge B is broken by concentrating on the region on the inlet 21 side where the water content is high and the bridge B is likely to occur, and by continuously blowing out the blown air in the direction of the rotation axis where the object to be dried R moves. It is even more efficient.

While the object R to be dried stays in the main body shell 2, the water content gradually decreases and dries due to repeated contact with the heating pipe 331 and stirring, and eventually the dried object R is dried from the discharge port 22. It becomes D and is discharged. The object to be dried R staying in the main body shell 2 is the input of the object to be dried R from the input port 21, the discharge of the dry substance D from the discharge port 22, and the rotating multi-tube heating tube 3. The angle 371, the lifter 372, and the feed vane 373 gradually move to the discharge port side by a concerted transport action such as a scraping action of the object to be dried R staying in the main body shell 2. The vapor evaporated from the object to be dried R is discharged from the exhaust port 24 together with the carrier air, sent to the dust collector 41, subjected to a predetermined treatment such as removal of fine powder, and then passed through the exhaust blower 42. It is exhausted to the outdoors after being appropriately deodorized. Further, after a lapse of a predetermined time after the object R to be dried is charged, the supply blower 51 and the heater 52 are driven, and the exhaust air of, for example, about 100 ° C. discharged from the exhaust port 24 is reduced to, for example, about 120 ° C. by the heater 52. After heating, it may be supplied as carrier air from the carrier air port 23. Further, the exhaust air discharged from the exhaust port 24 may be supplied to the rotary joint 32 on the inlet side as blowout air. By doing so, the exhaust air discharged from the exhaust port 24 can be circulated and used for the carrier air and the blown air.

Next, the dryer according to the second embodiment of the present invention will be described. In the subsequent description, the differences from the dryer 1 of the first embodiment shown in FIGS. 1 to 4 will be mainly described, and the components having the same names as the components described so far will be described. The explanation will be given with the reference numerals used up to, and duplicate explanations may be omitted.

FIG. 6A is a diagram showing a mode corresponding to FIG. 3 in the dryer of the second embodiment of the present invention.

The dryer 1 of the present embodiment includes a main body shell 2 and a multi-tube heating tube 3 which are larger than the dryer 1 of the first embodiment shown in FIGS. 1 to 4, and is as shown in FIG. 6 (a). In addition, it has a large number of heating tubes 331 as compared with the first embodiment. The air purge tube 332, which is hatched in the figure, is a heating tube L on the virtual line L, in which the outermost heating tubes 331 of the plurality of heating tubes 331 are connected by a straight line in the rotation direction. It is arranged in a state of being sandwiched between 331.

FIG. 6B is a diagram showing a modified example in which the arrangement of the air purge pipe 332 is changed with respect to the dryer of the second embodiment shown in FIG. 6A.

In this modification, the air purge pipe 332 is arranged outside the virtual line L with respect to the virtual line L connecting the heating pipes 331 arranged on the outermost side with a straight line in the rotation direction. That is, the position of the air purge pipe 332 is not limited as long as it is on the virtual line L or outside the virtual line L. Further, in this example, the heating tubes 331 are arranged in a staggered pattern as an example, but the arrangement is not limited, such as a grid pattern or a concentric array centered on the central axis of rotation.

FIG. 7 is a diagram showing a mode corresponding to FIG. 2 in the dryer according to the third embodiment of the present invention.

FIGS. 1 to 4 show that the dryer 1 of the present embodiment has the multi-tube heating tube 3 provided with the intermediate header 37 and the air purge tube 332 arranged only in the inlet side region. It is mainly different from the dryer 1 of the first embodiment shown.

As shown in FIG. 7, the multi-tube heating tube 3 of the present embodiment includes a hollow intermediate header 37 between the input port side header 35 and the discharge port side header 36. A plurality of heating pipes 331 are provided between the intermediate header 37 and the discharge port side header 36, and a plurality of heating pipes 331 and a plurality of air purge pipes 332 are provided between the intermediate header 37 and the input port side header 35. It is provided. Note that, as in FIG. 2, only the air purge pipe 332 located at the uppermost portion of the plurality of air purge pipes 332 is shown in FIG. 7.

In the present embodiment, when saturated steam is supplied from the rotary joint 32 on the discharge port side, the saturated steam passes from the header 36 on the discharge port side through a plurality of heating tubes 331 as shown by the white arrows in FIG. It enters the intermediate header 37, and further reaches the second space V of the input port side header 35 from the intermediate header 37 through a plurality of heating tubes 331. As a result, the heating tube 331 is maintained in a state of being heated to a substantially constant temperature in the direction of the rotation axis. The drain generated by condensing the saturated steam in the heating pipe 331 flows toward the inlet side and collects in the intermediate header 37 and on the bottom side of the inlet side header 35 in the second space V. As the amount of drain accumulated in the intermediate header 37 and the second space V increases, as shown by the dotted arrow in FIG. 2, the discharge port side eventually passes through the heating pipe 331 located at the lower part in the figure. It flows toward and collects on the bottom side in the discharge port side header 36. The drain collected in the discharge port side header 36 is discharged from the multi-tube heating pipe 3 by the drain device 38.

When blown air is supplied from the rotary joint 32 on the inlet side, this blown air flows through the air purge pipe 332 from the first space S of the header 35 on the inlet side as shown by the solid arrow in FIG. 7, and a plurality of blown airs are blown. It is blown out from the outlet 332a toward the outside. In the present embodiment, the air purge pipe 332 is arranged only between the input port side header 35 and the intermediate header 37. As a result, blown air is blown out from the air purge pipe 332 on the inlet side where the bridge B (see FIG. 3) is likely to occur, and the heating pipe 331 is arranged in place of the air purge pipe 332 on the outlet side to transfer heat to the heating pipe 331. A mode of increasing the area is adopted.

FIG. 8 is a diagram showing a mode corresponding to FIG. 1 in the dryer according to the fourth embodiment of the present invention.

The dryer 1 of the present embodiment is mainly different from the dryer 1 of the first embodiment shown in FIGS. 1 to 4 in that it is provided with a circulation path 6.

As shown in FIG. 8, the circulation path 6 includes a supply blower 61, branches from the exhaust path 4 and is connected to the supply blower 61, and the supply blower 61 is connected to the first circulation path 6A and the second circulation path 6B. It is branched. The circulation path 6 is configured so that outside air can be introduced before connecting to the supply blower 61.

The first circulation path 6A is connected to the carrier air port 23 via the heater 63, and a part of the gas flowing through the exhaust path 4, for example, about 100 ° C., is heated by the heater 63 to, for example, about 120 ° C. After that, it is supplied as carrier air from the carrier air port 23 into the main body shell 2. The second circulation path 6B is connected to the rotary joint 32 on the inlet side, and a part of the gas flowing through the exhaust path 4 is supplied to the air purge pipe 332. A path connecting the exhaust port 24 to the air purge pipe 332, that is, a path through which the exhaust air discharged from the exhaust port 24 flows through the exhaust path 4 and the circulation path 6 including the second circulation path 6B and flows to the air purge pipe 332. However, it corresponds to an example of a supply route. If necessary, each path is provided with a flow rate adjusting means (not shown) such as a damper in order to adjust the flow rate.

The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the claims. For example, in the above embodiment, the air purge pipes 332 that blow out the blown air toward the scraping members are arranged one by one, but the blown air is blown out from the plurality of air purge pipes 332 toward the scraping members. Alternatively, a portion where blown air is not blown out may be provided between the scraping members within a range that does not hinder, and the portion may be used as a heating pipe 331 to increase the heat transfer area. Further, the air purge pipe 332 may be arranged so as to surround the plurality of heating pipes 331. That is, in the multi-tube heating tube 3 shown in FIG. 3 or FIG. 6A, a mode in which all of the heating tubes 331 arranged on the virtual line L are replaced with air purge tubes 332 can also be adopted. Further, in the above embodiment, the member is not provided on the rotating shaft portion, but a heating tube 331 or a solid shaft member may be provided.

It should be noted that even if the constituent requirements are included only in the descriptions of the embodiments and modifications described above, the constituent requirements may be applied to other embodiments and modifications.

1 Dryer 2 Main body shell 21 Input port 22 Discharge port 23 Carrier air port 24 Exhaust port 3 Multi-tube heating pipe 32 Rotary joint 331 Heating pipe 332 Air purge pipe 332a Outlet 371 Angle 372 Lifter 373 Feed blade 4 Exhaust path 6 Circulation path B Bridge L Virtual line R Dried material

Claims (6)

The main body shell to which the object to be dried is put,
A multi-tube heating tube that rotates around a rotation axis in the main body shell is provided.
The multi-tube heating tube has a plurality of heating tubes extending along the rotation axis outside the rotation axis, and an air purge tube.
The plurality of heating tubes are arranged at intervals from each other, and dry the object to be dried by coming into contact with the object to be dried put into the shell of the main body.
The air purge pipe is arranged on a virtual line connecting the outermost heating pipes among the plurality of heating pipes with a straight line in the rotation direction or outside the virtual line, and is centered on the rotation axis. A dryer characterized by having an outlet for blowing off a bridge generated outside the air purge pipe by blowing out gas from the side to the outside. The multi-tube heating tube is provided outside the air purge tube at a distance from each other in the rotation direction, and has a plurality of scraping members for scraping the object to be dried in the main body shell. ,
The dryer according to claim 1, wherein the air purge pipe blows gas from the outlet toward between the plurality of scraping members. The dryer according to claim 1 or 2, wherein the air outlet blows gas toward the upstream side in the rotation direction. The dryer according to any one of claims 1 to 3, wherein the air purge pipe is provided with a plurality of outlets at intervals in the direction of the rotation axis. The main body shell has a charging port provided on one side in the rotation axis direction for charging the object to be dried, and the other side in the rotation axis direction from which the dried product dried from the object to be dried is discharged. It has an outlet provided in
The dryer according to any one of claims 1 to 4, wherein the outlet is provided at a position closer to the inlet than the outlet. The main body shell has an exhaust port that discharges steam evaporated from the object to be dried together with carrier air supplied into the main body shell.
Any of claims 1 to 5, wherein a supply path for supplying the gas discharged from the exhaust port to the air purge pipe is provided between the exhaust port and the air purge pipe. The dryer according to item 1.

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