JP6625479B2 - Flash dryer - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flash dryer, and more particularly, to a flash dryer for drying a high water content containing coarse particles.

  Patent Literature 1 discloses that an object to be dried is dried by an air flow while a heavy object such as an iron piece included in the object to be dried is selectively sorted, and the object to be dried after removing the heavy object is further dried by a vortex air flow. A flash dryer is disclosed.

  Further, in Patent Literature 2, a drying target is dried with hot air while selecting a high specific gravity contained in the drying target, and the drying target after the large specific gravity is separated is further dried with hot air. A flash dryer is disclosed.

JP 2000-304439 A JP 2012-180943 A

  In the flash dryers described in Patent Documents 1 and 2, although a lump such as a heavy substance contained in a drying target is separated, it is possible to avoid a situation in which the lump remains in the flash dryer. In addition, among the fallen objects due to the specific gravity difference sorting, fine particles that are insufficiently dried and fall due to the weight of moisture are also included. The above Patent Documents 1 and 2 consider the fine particles that are insufficiently dried. There was room for improvement.

  Therefore, the present invention has been made in view of the above-mentioned problems in the related art, and is intended to efficiently dry a drying target such as a high water content including a lump (hereinafter, referred to as “coarse particles”). It is an object of the present invention to provide a flash dryer capable of performing the following.

  In order to achieve the above object, the present invention is a flash dryer, which is a flash dryer for drying an object to be dried by an airflow of a drying gas, a sieve for sorting falling objects falling from the flash dryer, It is characterized by comprising a route for returning the material passed through the sieve to the flash drying unit, and a route for discharging the residue of the sieve outside the machine.

  According to the flash dryer according to the present invention, since the falling objects from the flash drying section are sorted by the sieve, the fine particles that are not sufficiently dried are not discharged to the outside as coarse particles, and the drying target including the coarse particles is not removed. The object can be dried efficiently.

  In the flash dryer, the flash drying unit may discharge the dried product together with the drying gas.

  Further, it is possible to provide a drying / transporting unit that transports the drying target and the drying dust to the flash drying unit while mixing and stirring the drying target, and the flash drying unit is configured to dry the mixture from the drying / transporting unit. can do. Thereby, the object to be dried can be dried more efficiently. In order to further improve the drying efficiency, a route for returning the passing material of the sieve to the drying and conveying unit may be provided instead of the route for returning the passing material of the sieve to the flash drying unit.

  As described above, according to the present invention, it is possible to provide a flash dryer capable of efficiently drying a drying target including coarse particles.

It is the schematic which shows one Embodiment of the flash dryer which concerns on this invention.

  Next, an embodiment of a flash dryer according to the present invention will be described with reference to FIG. In the figure, the solid arrow indicates the flow of the solid, and the broken arrow indicates the flow of the gas.

  The flash dryer 1 includes a drying transport unit 2 that transports the drying object O and the drying dust D1 while mixing and stirring the same, and a flash drying unit that dries the mixture M from the drying transport unit 2 by a stream of the drying gas G. 3, a sieve 4 for selecting the falling objects F falling from the flash drying unit 3, and a route 5 for returning the passing material of the sieve 4 to the drying and conveying unit 2.

  The drying / conveying unit 2 includes a supply port 2a through which the drying target O and the drying dust D1 are supplied, a discharge port 2b that discharges the mixture M, a rotating shaft 2c rotated by a drive source (not shown), and a rotating shaft 2c. And a plurality of paddles 2d provided at intervals. Note that a screw may be provided instead of the paddle 2d.

  The flash drying unit 3 is formed in a room shape having an internal space in which the upper part 3a has a rectangular parallelepiped shape and the lower part 3b has a truncated pyramid shape. An inlet 3c for the drying gas G is provided on the right side of the upper portion 3a, a supply port 3d for supplying the mixture M from the drying transfer section 2 on the left side, and an exhaust port 3e for discharging the exhaust gas G1 and the fine particles D2 on the ceiling. Are provided. In the illustrated example, the exhaust port 3 e is formed above the flash drying unit 3, but may be provided on the side of the flash drying unit 3. On the other hand, at the lower end of the lower part 3b, an outlet 3f for discharging the mixture M other than the fine particles D2 (falling object F) is formed.

  The sieve 4 only needs to be able to efficiently sort the falling objects F falling from the flash drying unit 3, and various sieves such as a vibrating sieve can be appropriately selected according to the drying target O.

  The operation of the flash dryer 1 having the above configuration will be described in detail with reference to FIG.

  The drying object O and the drying dust D1 are supplied to the supply port 2a of the drying and transporting unit 2 and are transported while mixing and stirring them. Thereby, the drying target O can be dried to some extent before flash drying. The object to be dried O is a highly hydrated material such as hydrated clay-based waste and agricultural / fishery residue. As the drying dust D1, the fine powder D2 having a calorific value, a cement kiln dust, or the like can be used. You.

  The mixture M mixed and stirred in the drying / conveying section 2 is supplied to the flash drying section 3 through the outlet 2b and the supply port 3d, and is dried by the stream of the drying gas G flowing from the inlet 3c. The temperature and the flow rate of the drying gas G are appropriately set according to the amount of the mixture M and the water content.

  The fine particles D2 in the mixture M dried by the drying gas G in the drying transport unit 2 are discharged from the exhaust port 3e together with the exhaust gas G1. On the other hand, the falling matter F falling from the flash drying unit 3 of the mixture M reaches the sieve 4 through the discharge port 3f, and is separated into fine particles D3 passing through the sieve 4 and lumps B remaining on the sieve 4. Is done. The opening of the sieve 4 is appropriately set according to the drying target O.

  The fine particles D3 contain water due to insufficient drying in the flash drying unit 3 and are included in the falling object F due to the weight of the water, and are originally dried together with the fine particles D2. Since it is to be collected, it is returned to the drying / conveying unit 2 via the route 5 and dried again. On the other hand, the lump B is discharged outside the machine.

  As described above, according to the present embodiment, since the falling object F from the flash drying unit 3 is sorted by the sieve 4, the fine particles D3 that are insufficiently dried are not removed as the lump B, and the coarse particles D are not removed. Can be efficiently dried.

  In the above embodiment, the case where the drying and conveying unit 2 is provided has been described. However, depending on the water content of the drying object O, the drying object O is directly provided without the drying and conveying unit 2 and the flash drying unit 3 Can also be supplied. Even in the flash dryer 1 including the drying and conveying unit 2, when the moisture content of the fine particles D3 is low, the fine particles D3 are not returned to the drying and conveying unit 2 via the route 5 but directly to the flash drying unit 3. May be returned.

DESCRIPTION OF SYMBOLS 1 Flash dryer 2 Dry conveyance part 2a Supply port 2b Discharge port 2c Rotating shaft 2d Paddle 3 Pneumatic drying part 3a Upper part 3b Lower part 3c Inlet 3d Supply port 3e Exhaust port 3f Discharge port 4 Sieve 5 Route B Lump D1 Dry dust D2, D3 Fine particles F Falling object G Drying gas G1 Exhaust gas M Mixture O Drying object

Claims (4)

A flash drying unit for drying a drying target by a flow of a drying gas,
A sieve for sorting falling objects falling from the flash drying unit;
A route for returning the passing material of the sieve to the flash drying unit;
And a route for discharging the residue of the sieve outside the machine.   The flash dryer according to claim 1, wherein the flash drying unit discharges a dried product together with the drying gas. A drying and conveying unit that conveys the drying target and the drying dust to the flash drying unit while mixing and stirring,
The flash dryer according to claim 1, wherein the flash drying unit dries the mixture from the drying transport unit.   4. The flash dryer according to claim 3, further comprising a route that returns the passed material of the sieve to the drying and conveying unit, instead of a route of returning the passed material of the sieve to the flash drying unit. 5.

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