JPH0537194Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The present invention is to move a powder or granular material to be dried spread out on a flat surface while stirring and bring it into contact with hot gas or hot steam. The present invention relates to a multi-shaft multi-stage drying device for drying.

(Prior art) Conventionally, a drying device that reheats circulating gas has been known as a drying device for powder and granules, but when using this device, dust gets mixed into the circulating gas system and the heating device is contaminated by the dust. There is a problem in that it tends to cause major obstacles to driving.

A drying device used in a Nichols-Hershtiyov type incinerator is known as a solution to this problem. This drying device has a vertical shaft mounted inside a cylindrical main body, and horizontally rotates feeding blades mounted on the vertical shaft in multiple stages. It has a structure in which the dried material is dried while being stirred and then sent to the lower stage, and since the material to be dried is not put into the drying gas stream and dried, it has the advantage that no dust is scattered.

(Problems to be solved by the invention) Despite the above-mentioned advantages, the Nichols-Hershtiyov type drying device has a single-unit, single-shaft structure, so if it is made into a large structure,
There are technical problems such as large distortion due to thermal deformation that accumulates, making maintenance management difficult, and making the mechanism complicated and manufacturing process difficult, as well as increasing operating costs.

In view of the above-mentioned problems, the present invention provides a multi-shaft, multi-stage drying device that generates less dust, causes less thermal deformation of the feeder blades, etc., is easy to manufacture, and is less likely to malfunction.

[Structure of the idea]

(Means for Solving the Problems) The multi-axis multi-stage drying device of the present invention forms a hot gas flow path with a substantially horizontal drying surface provided in multiple stages in a drying chamber, and a rotation range is formed on this drying surface. A large number of feeder blades are arranged at mutually overlapping intervals, and the feeder blades of each stage are mounted on a plurality of parallel vertical rotating shafts penetrating the drying surfaces of the plurality of stages. By rotation, the material to be dried is sequentially transferred from the upper stage to the lower stage and brought into contact with hot gas.

(Function) The multi-axis multi-stage drying device of the present invention supplies, for example, sludge material as the material to be dried onto the drying surface in the drying chamber, and rotates the plurality of sending blades on the drying surface to dry the material. As the feed blade rotates on the surface, it is sent from one end to the other while being agitated, and falls from the other end to the drying surface in the lower stage, and in the same way, it is sent while being stirred on the drying surface of each stage, and at the same time, it is sent to the lower part of the drying chamber. It is introduced from the air and is dried by contacting with hot gas. At this time, the material to be dried is sent over the drying surface by the sending blades, so that the proportion of dust caused by drying mixed into the exhaust gas is extremely small.

Further, the objects to be dried that have accumulated on the drying surface rub against each other, and the dry parts of the surface peel off, exposing the moist parts inside and drying the whole.

(Embodiment) The configuration of an embodiment of the present invention will be explained with reference to FIGS. 1 to 3.

Reference numeral 1 denotes a drying chamber made of castable refractory material, in which a drying material inlet 2 is formed on one side of the upper part, and a drying material outlet 3 is formed on the other side of the lower part. A supply device 6 including a hopper 4 and a screw 5 is connected to the drying material inlet 2 .

Further, the interior of the drying chamber 1 is divided vertically into a plurality of stages by a heat-resistant metal plate 8 whose upper surface serves as a drying surface 7, and one end of this metal plate 8 and both edges in the width direction
is inserted into the cut groove 9 formed on the inner wall of the drying chamber 1.
A plurality of stages of drying surfaces 7 are formed by being fixed therein. Furthermore, one end of the metal plate 8 on the opposite side of each stage is cut out to provide a communication port 10 that communicates the upper and lower drying surfaces 7.
is formed, and a plurality of stages of drying surfaces 7 are connected in series through this communication port 10. The to-be-dried material inlet 2 is communicated with the drying surface 7 at the top, and the drying material drop port 3 is communicated with the communication port 9 at the bottom. Further, a hot gas inlet 11 and a gas outlet 12 are opened in the side wall portion of the drying chamber 1, which constitutes one of the side walls of the lowermost and uppermost drying surfaces 7, respectively. Further, hot gas flow paths are formed in the plurality of stages of drying surfaces 7 from the lower stage side to the upper stage side.

Reference numeral 13 denotes a vertical rotating shaft that is interlocked with each other by gears, and a plurality of shafts are vertically arranged in parallel and pass through the metal plates 8 of each stage, and both ends are rotatably mounted above and below the drying chamber 1. There is. Furthermore, each rotating shaft 13 has
A plurality of feed blades 14 arranged on the drying surface 7 of each metal plate 8 are mounted on an axis, and the feed blades 14
The interval between the rotating shafts 13 is determined such that a part of the rotational radius of the rotating shaft 13 overlaps with that of the adjacent feeding blade 14, and the spacing of the rotating shaft 13 is determined so that the feeding blade 14 does not contact the boss portion 15 of the adjacent rotating shaft 13. Positioning is performed by engaging the key 16 with the key groove 17 of the feed blade 14.

Further, the inner wall surface of the drying chamber 1 is provided with feeding blades 14
It is curved in an arc along the radius of rotation. A gear box 18 is provided above the drying chamber 1, and a drive reduction motor 19 rotates the plurality of rotating shafts 13 alternately in opposite directions via internal gears (not shown).

Note that when assembling the device of the above embodiment, the third
As shown in the figure, one end and both sides of the metal plate 8 are respectively inserted into the grooves 9 of the drying chamber 1, and then the sending blades 14 are positioned and placed on the drying surface 7 of the metal plate 8 and temporarily placed. Next, the keys 16 of the rotating shaft 13 are sequentially inserted into the key grooves 17 starting from the upper feed blade 14, and the assembly is completed. The assembly hole should have sufficient clearance.

Next, the operation of the above embodiment will be explained.

The material to be dried supplied from the supply device 6 is supplied from the inlet 2 of the drying chamber 1 onto the drying surface 7 of the uppermost metal plate 8, and is sent to the feed blade 14 on the drying surface 7 in the direction of the arrow in FIG. rotates and pushes out the material to be dried in the direction of rotation and in the direction of the wall surface. Then, it is pushed from the opposite direction by the next sending blade 14 whose radius partially overlaps, and is pushed out into the rotational radius of the third sending blade 14, and progresses sequentially while being stirred on the drying surface 7, until the tip of Communication port 10
It flows down onto the drying surface 7 of the next stage and proceeds to the drying surface 7 of the lower stage in the same way.

At the same time, the hot gas introduced from the hot gas inlet 11 at the bottom of the drying chamber 1 travels from the lowest metal plate 8 in the opposite direction to the dried material and absorbs moisture from the dried material, and the hygroscopic gas is exhausted upward. It is discharged from the port 12.

The material to be dried is dried as it advances to the lower stage, and is discharged to the outside of the drying chamber 1 from the communication port 10 of the metal plate 8 at the lowest stage via the discharge port 3.

In the above embodiments, the material of the metal plate 8 is selected depending on operating conditions such as temperature, but if a heat-resistant metal is used, it can be applied to hot gases up to about 800°C. If the temperature is even higher, you can construct an arch made of refractory bricks. In this case, the distance between the upper and lower drying surfaces 7 is large.

The rotating shaft 13 can handle hot gas temperatures up to about 500° C. by selecting the right material, but needs to be cooled above that temperature.

Since the metal plate 8, rotating shaft 13, and sending blade 14 all have simple structures, almost no deformation occurs due to thermal expansion.

With the structure of the above example, the drying chamber 1 has an area of 15 square meters, the drying surface 7 has five stages, and the drying device with four rotating shafts 13 is used in the drying part of the sludge incinerator with a gas circulation type drying system. It was operated at a drying gas temperature of 450°C, but no signs of trouble due to thermal deformation were observed. Further, no contamination of the heater by dust was observed.

[Effect of idea]

According to the present invention, since the material to be dried is sent out while stirring the material to be dried while rotating a large number of feeding blades on a flat drying surface in multiple stages in the drying chamber, compared to a device that dries the material to be dried in a fluidized airflow. generates less dust. Furthermore, since the objects to be dried rub against each other on the drying surface due to the agitation of the feed blades, the dry portions on the surface peel off and the moist portions inside are exposed, thereby shortening the drying time. In addition, since it is a multi-shaft multi-stage type with multiple drying surfaces in the drying chamber and multiple feed blades rotating on each drying surface, the feed blade can be made smaller and less deformed compared to a single-unit, uniaxial type dryer. In addition, it is easier to manufacture and the occurrence of failures is reduced.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of the multi-shaft multi-stage drying device of the present invention, FIG. 2 is a cross-sectional plan view of the same, and FIG. 3 is an exploded perspective view showing the assembled state of the metal plate, rotating shaft, and feeding blade. 1... Drying chamber, 7... Drying surface, 13... Rotating shaft, 14... Feeding blade.

Claims (1)

[Scope of utility model registration request] A hot gas flow path is formed by a substantially horizontal drying surface provided in multiple stages in the drying chamber, and a large number of feeding blades are arranged on this drying surface at intervals such that their rotation ranges overlap with each other. The feeder blades of each stage are mounted on a plurality of parallel vertical rotating shafts penetrating the drying surface, and the rotation of each feeder blade sequentially moves the material to be dried from the upper stage to the lower stage, and the hot gas is A multi-shaft multi-stage drying device characterized by contact.