JPH0545875B2 - - Google Patents

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,
Drying of iron ore, coal, sand, etc., zinc ore, iron sulfide ore,
It is known to be used for roasting nickel ore, incinerating sewage sludge, human waste sludge, garbage, etc., and thermally decomposing rubber, plastic, etc.

This fluidized bed drying device is, for example,
Various types of dryers are known, as described in "Fluidized Drying Equipment" in the December 1952 issue of "Industrial Machinery" and "Drying Equipment Manual" published by Nikkan Kogyo Shimbun in 1978. .

Figure 3 shows an example of a fluidized bed type drying device, where 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 furnace with a gas distribution plate 6 arranged inside and a product outlet 7 arranged on the side wall. Reference numeral 5 denotes an air introduction pipe which introduces hot air from the air heater 3 into the fluidized bed drying furnace 4. 8 is a supply device;
Raw materials are supplied to a fluidized bed drying furnace 4. The product outlet 7 is provided with a partition plate 9 that can be opened and closed. 10 is a product discharge box provided outside the partition plate 9 to cover the product outlet 7;
11 is a dryer product discharge valve provided at the bottom of this product discharge box 10, and 12 is this dryer product discharge valve 1.
This is a product discharge duct that communicates with 1. Reference numeral 13 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. 1
5 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. Reference numeral 18 denotes a pneumatic transport pipe for transporting the product using air. An air intake port 18A is provided at one end of the pneumatic transport pipe 18, and the product is supplied from the feeder 14 to the middle of the pneumatic transport pipe 18.

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 flows from the top of the fluidized bed drying furnace 4 to the exhaust pipe 17 along with a small amount of product.
is guided to the cyclone 16 via the cyclone 16.

[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), there is sufficient water head (static pressure), The outflow speed is also high, but as the outflow progresses, the height of the fluidized bed 27 becomes lower and the water head becomes smaller, making natural outflow difficult. Moreover, the hot air that has passed through the gas distribution plate 6 is
Regardless of the shape of the gas distribution plate 6 (perforated plate, nozzles) or the orientation of the hot air blowing holes, the remaining product will eventually be drawn upwards in the fluidized bed drying oven 4 in order to draw a streamline upwards. Although it moves, it does not easily move to the product outlet 7. 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, incinerators, and 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 problems]

In order to achieve the above object, the present invention introduces hot air from an air introduction pipe into a fluidized bed furnace that has a gas distribution plate inside and a product outlet on the side, and also introduces raw material from a supply device. A fluidized bed is formed on the gas distribution plate by supplying the gas, and a small amount of product is discharged from the fluidized bed furnace along with the exhaust gas to the cyclone via the exhaust pipe, and the product discharged from the product outlet and the cyclone is In a fluidized bed drying device, the product is introduced into an air transport pipe with an air intake at one end, and then transported by the air transport pipe to an air transport cyclone arranged separately from the cyclone. The pipe is connected in the middle of the pipe via a bypass pipe equipped with a bypass damper, and 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. Yes, Motsupara,
The parts related to the invention will be explained.

In the figure, 19 is a bypass pipe, and product outlet 7
The product discharge box 10 provided so as to cover the air transport pipe 18 is connected to the middle of the air transport pipe 18, and a bypass damper 19A is provided in the middle. Reference numeral 18B denotes an inflow air regulating valve, which is provided in the middle of the air transport pipe 18 and connects the connection point 20 with the bypass pipe 19 and the air intake port 18A.
It is located between.

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 from the air intake port 18A by closing the bypass damper 19A and opening the inflow air regulating valve 18B appropriately. While the product is appropriately discharged from the product discharge port 7 by the water head, the product discharge box 10→dryer product discharge valve 11→product discharge duct 12→vibration screen 13→feeder 14→air transport pipe 18→pneumatic cyclone 21 → Pneumatic cyclone product discharge valve 2
The products are sent in the order of 1A→product recovery duct 21B→product hopper 25.

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 regulating valve 18B is throttled, and the suction fan 22 is operated, the hot air in the fluidized bed drying furnace 4 is also guided to the bypass pipe 19, and the bypass pipe 19
A suction force is generated within. As a result, the residual product on the gas distribution plate 6 is discharged to the product outlet 7, and a small amount of product is transported to the pneumatic cyclone 21 through the bypass pipe 19 and the air 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 force is generated in the bypass pipe 19 by the suction fan 22, 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 above-mentioned 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. Fully 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... pneumatic cyclone, 22... suction fan, 26... return pipe, 27... fluidized bed.

Claims (1)

[Claims] 1. By introducing hot air from an air introduction pipe into a fluidized bed furnace that has a gas dispersion plate inside and a product outlet on the side, and supplying raw materials from a supply device. A fluidized bed is formed on the gas distribution plate, and a small amount of product is discharged from the fluidized bed furnace along with the exhaust gas through an exhaust pipe line into a cyclone. In a fluidized bed drying device, the product is guided to an air transport pipe provided with a cyclone, and the product is further transported by the air transport pipe to an air transport cyclone arranged separately from the cyclone.
Connect the product outlet and the middle of the air transport pipe through a bypass pipe equipped with a bypass damper, and install an inflow air regulating valve between the connection point with the bypass pipe and the air intake in the middle of the air transport pipe. A fluidized bed drying device characterized by being provided with. 2. The fluidized bed drying apparatus according to claim 1, wherein a suction fan is connected to the air discharge hole of the pneumatic cyclone, and the suction fan and the air introduction pipe are connected by a return pipe.