JPS63131981A - Fluidized bed type drier - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fluidized bed drying apparatus, and in particular to a product discharge mechanism thereof.

[Conventional technology]

Conventionally, fluidized bed drying equipment uses synthetic resin.

Iron ore 1 Dried coal, sand, etc., zinc ore, iron sulfide ore.

It is known to be used for roasting nickel ore, incinerating sewage sludge, raw sludge, garbage, etc., and thermally decomposing rubber, plastic, etc.

This fluidized bed drying device is, for example, “Fluidized Drying Device” in the December 1952 issue of “Industrial Machinery” or r1978
Various types of dryers are known, as described in the ``Drying Equipment Manual'' published by Nikkan Kogyo Shinbunsha in 2010.

Figure 3 shows an example of a fluidized bed drying device, in which 1 is an air filter, 2 is a blower attached to the rear of the air filter 1, 3 is an air heater that warms the air sent from the blower, and 4 is a fluidized bed dryer. It is a layered furnace, with a gas distribution plate 6 arranged inside and a product take-out lower on the side wall. 5
is an air introduction pipe which introduces hot air from the air heater 1 into the fluidized bed drying furnace 4. 8 is a supply device;
Raw materials are supplied to the fluidized bed furnace 4.

A partition plate 9 that can be opened and closed is provided in the product take-out lower. 10 is a product discharge box provided outside the partition plate 9 to cover the product removal lower; 11 is the product discharge box 10;
A dryer product discharge valve 12 provided at the bottom of the dryer product discharge valve 12 is a product discharge duct that communicates with this dryer product discharge valve 11. 1
Reference numeral 3 denotes a vibrating screen for removing foreign matter from the product sent through the product discharge duct 12, and a feeder 14 is arranged below this vibrating screen. 15 is a container for receiving the foreign matter removed by the vibrating screen 13.

A cyclone 16 communicates with the fluidized bed drying furnace 4 via an exhaust pipe 17. 16A is a cyclone product discharge valve, and 16B is a product recovery duct connected to the cyclone product discharge valve 16A, which is connected to the product discharge duct 12. 18 is a pneumatic transport pipe that transports the product by air;
An air intake port 18A is provided at one end of the air transport pipe 1.
In the middle of B, the product is supplied from the supply machine 14.

In this fluidized bed drying furnace 4, the raw material is supplied onto the gas distribution plate 6 from the supply device 8, and when hot air at a desired temperature is sent from the lower part of the gas distribution plate 6, the raw material moves on the gas distribution plate 6. The raw material particles are suspended in the gas, forming a so-called fluidized bed 27 in which the raw material particles and the gas are mixed, and within this fluidized bed 27, the raw material particles are moved and dried while making vigorous contact with each other. There is. On the other hand, the exhaust gas is guided from above the fluidized bed furnace 4 to the cyclone 16 through the exhaust pipe 17 along with a small amount of product.

[Problem that the invention seeks to solve]

However, in this conventional fluidized bed drying oven 4, when the fluidized bed 27 is sufficiently high (several centimeters to several tens of centimeters or more),
Because there is sufficient water head (static pressure), the outflow velocity to the product take-out lower is also high, but as the outflow progresses, the fluidized bed 2
7 becomes lower and the water head becomes smaller, making it difficult for natural outflow.

Moreover, the hot air that has passed through the gas distribution plate 6 is
Regardless of the shape (perforated plate, nozzles, etc.) and the direction of the hot air outlet, the remaining product will eventually move upward and downward to draw a streamline upwards inside the fluidized bed drying oven 4. ,
This means that it cannot be easily moved to the product take-out lower.

Therefore, the remaining product could not be completely discharged from the fluidized bed drying oven 4 in a short time.

For these reasons, it is not possible to cope with the recent multi-product production model in which a single fluidized bed drying furnace efficiently produces many different products. In particular, when switching from one type of product to another, it is difficult to completely discharge the previous type from the fluidized bed drying oven in a short period of time to achieve good results in terms of productivity improvement and labor savings. be.

Note that this problem exists not only in fluidized bed drying furnaces but also in roasting furnaces and incinerator-two-pyrolysis furnaces.

[Purpose of the invention]

The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a fluidized bed drying device that can discharge a product from a fluidized bed in a short time.

Means for Solving Problem c] In order to achieve the above object, the present invention provides a fluidized bed furnace in which a gas distribution plate is arranged inside and a product outlet is arranged on the side.
A fluidized bed is formed on the gas distribution plate by introducing hot air from the air introduction pipe and supplying raw materials from the supply device.
A small amount of product along with the exhaust gas is discharged from the fluidized bed furnace through an exhaust pipe line to a cyclone, and the product discharged from the product outlet and the cyclone is guided to an air transport pipe with an air intake port at one end, and then In a fluidized bed drying device in which the product is transported by an air transport pipe to a pneumatic cyclone arranged separately from the cyclone, the product outlet and the middle of the air transport pipe are connected via a bypass pipe equipped with a bypass damper. An inflow air regulating valve is provided in the middle of the air transport pipe between the connection point with the bypass pipe and the air intake port.

[Action of the invention]

According to the present invention, during drying operation, by closing the bypass damper and opening the inflow air regulating valve, air is taken into the air transport pipe from the air intake port, and this air is taken out from the product outlet and the cyclone. Transport the product to the air cyclone.

When discharging residual product, the bypass damper is opened and the inflow air adjustment valve is throttled.The suction force generated in the bypass pipe sends the residual product on the gas distribution plate to the product outlet, and a small amount of product is bypassed. Can be transported to pneumatic cyclone via pipe, pneumatic transport pipe.

[Embodiments of the invention]

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a fluidized bed drying apparatus according to a first embodiment of the present invention, and the structure except for the parts related to the invention is the same as that of the conventional one, and the explanation thereof is omitted here. However, only the parts related to the invention will be explained.

In the figure, reference numeral 19 denotes a bypass pipe that connects the product discharge box 10 provided so as to cover the product take-out lower to the middle of the air transport pipe 18, and a bypass damper 19A is provided in the middle of the pipe. 18B is an inflow air regulating valve, which is connected to the air transport pipe 18.
It is provided midway and located between the connection point 20 with the bypass pipe 19 and the air intake port 18A.

Next, the operation of this embodiment configured as described above will be explained.

The fluidized bed drying furnace 4 is supplied with hot air generated by the air heater 3 from below the gas distribution plate 6, and raw materials are supplied from the raw material supply device 8, as in the conventional case. A fluidized bed 27 is formed to dry the raw material particles. During drying operation, air is taken into the air transport pipe 18 through the air intake port 18A by closing the bypass damper 19A and opening the inflow air regulating valve 18B appropriately.

Then, the product is discharged from the product discharge lower as appropriate by the water head, and the product discharge box 10 - dryer product discharge valve 11
- Product discharge duct 12 - Vibrating screen 13 - Feeder 1
4-Air transport pipe 18-Air transport cyclone 21-Air transport cyclone Product discharge valve 21A→Product recovery duct) 21B=Product hopper 25 is sent in this order.

In this case, a small amount of product is sent from above inside the fluidized bed drying furnace 4 together with the exhaust gas to the cyclone 16, and after being collected by the cyclone 16, it is merged into the product discharge duct 12 from the product recovery duct 16B.

Therefore, when the drying process of the raw material is finished and the process is switched to another raw material process, it is necessary to discharge the remaining product in the fluidized bed drying furnace 4 in a short time.

In this case, when the bypass damper 19A is opened, the inflow air adjustment valve 18B is throttled, and the suction fan 22 is operated, the hot air in the fluidized bed drying furnace 4 is transferred to the bypass pipe 19.
Also, a suction force is generated within the bypass pipe 19. As a result, the remaining product on the gas distribution plate 6 is discharged to the product take-out lower, and a small amount of product is removed from the bypass pipe 19. transported to the pneumatic cyclone 21 through the pneumatic transport pipe 18,
It will be collected.

In this way, the residual product is completely removed from the gas distribution plate 6, and another raw material can be quickly fed into the fluidized bed drying oven 4.

In this embodiment, the suction fan 22 generates suction force in the bypass pipe 19, but the suction fan 22 can be generated by generating negative pressure in the pneumatic cyclone 21 by an appropriate means. Can be omitted.

Next, FIG. 2 shows a fluidized bed drying apparatus according to a second embodiment of the present invention, in which a suction fan 22 and an air introduction pipe 5 are connected by a return pipe 26, and a damper 26A is provided in the middle. At the same time, a damper 5A is provided in the middle of the air introduction pipe 5. By returning air to the air introduction pipe 5 using the suction fan 22 and adjusting the opening and closing of the damper 5A and the damper 26A, it is possible to increase the air supply capacity to the fluidized bed drying oven 4, or to increase the ability to supply air to the fluidized bed drying furnace 4. It is completely closed, the blower 2 is stopped, and the product can be fluidly discharged and transported by air using only the suction fan 22, thereby saving power.

Further, in the above embodiments, a drying furnace was described, but it goes without saying that the present invention can be applied to a roasting furnace, an incinerator, a pyrolysis furnace, etc.

〔Effect of the invention〕

As described above, according to the present invention, since the residual product is discharged using the suction force generated by the air transport pipe, the time for discharging the residual product can be shortened. Therefore, the furnace can be adapted to a production method in which many kinds of raw materials are processed with one furnace, and productivity can be improved and labor can be saved.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a fluidized bed dryer according to a first embodiment of the present invention, FIG. 2 is an explanatory diagram of a fluidized bed dryer according to a first embodiment of the present invention, and FIG. 3 is an explanatory diagram of a fluidized bed dryer according to a first embodiment of the present invention. FIG. 4... Fluidized bed furnace, 5... Air introduction pipe, 6... Gas distribution plate, 7... Product outlet, 8... Supply device, 9
... Partition plate, 10 ... Product discharge box, 16 ... Cyclone, 17 ... Exhaust pipe line, 18 ... Air transport pipe,
18A...Air intake port, 18B...Inflow air adjustment valve, 19...Bypass pipe, 19A...Bypass damper, 20...Connection point, 21...Air feeding cyclone, 2
2... Suction fan, 26... Return pipe, 27... Fluidized bed.

Claims (2)

[Claims] (1) Into a fluidized bed furnace that has a gas distribution plate inside and a product outlet on the side, hot air is introduced from an air introduction pipe, and raw materials are supplied from a supply device so that the gas distribution plate is A fluidized bed is formed in the furnace, and a small amount of product is discharged from the fluidized bed furnace along with the exhaust gas into a cyclone through an exhaust pipe, and an air intake port is provided at one end of the product outlet and the product discharged from the cyclone. In a fluidized bed drying device in which the product is introduced into a transport pipe and further transported by an air transport pipe to an air cyclone arranged separately from the cyclone, a bypass damper is installed between the product outlet and the middle of the air transport pipe. What is claimed is: 1. A fluidized bed drying device, which is connected via a provided bypass pipe, and further comprises an inflow air regulating valve located in the middle of the air transport pipe between a connection point with the bypass pipe and an air intake port. (2) Fluidized bed drying according to claim 1, characterized in that a suction fan is connected to the air exhaust hole of the pneumatic cyclone, and the suction fan and the air introduction pipe are connected by a return pipe. Device.