JPS61138690A - Fluidized layer dryer - Google Patents

Abstract

PURPOSE:To promote heat transfer, to carry out efficient dyring, and to prevent powder or granule from attaching to a hot plate, etc., by drying powder or granule by indirect heating with a hot plate, etc., and vibrating a fluidized layer itself and the hot plate, etc. CONSTITUTION:Powder or granule from the feed duct 2 is sent quantitatively by the rotary feeder 4, distributed uniformly to space between each of the hot plates 15, and made to flow in the fluidized bed 11. In the operation, the powder or granule is fluidized by vibration of the fluidized bed 11 by the vibra tion machine 14 and hot air from the hot air feed pipe 6, so it is successively transferred to the exist side. The powder or granule is dried by heating with the hot plates 15 and the hot air.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fluidized bed dryer that fluidizes and dries powder and granules.

[Conventional technology]

Conventionally, in order to dry granular materials such as raw coal for coke for steel manufacturing, there is a method in which the granular materials are fluidized and dried.

This is generally referred to as a fluidized bed dryer with indirect heating.Heating tubes or heating plates are placed in the fluidized bed where the powder and granules stay, and heating fluid is supplied to these tubes or plates, as well as fluidizing gas. It is configured to dry the fluidized powder by feeding it into the powder.

In addition, instead of indirect heating using heating pipes, etc.,
As shown in Figure 3-57 on page 96 of the "Drying Equipment Manual" published on March 30th, the entire dryer is vibrated to promote fluidization and hot air for fluidization and drying is supplied. Some devices have a structure in which drying is performed by drying.

[A problem that the invention attempts to solve]

However, in the former configuration, when drying a granular material with high wetness such as pulverized coal, the granular material tends to adhere to the heating tube and the heating plate and easily clog the heating tube and the heating plate.

In this way, fluidization tends to become unstable due to adhesion of powder and granules. Therefore, it is necessary to obtain sufficient cylinder velocity to create a fluidized bed state suitable for drying, and to sufficiently prevent the heating tubes and heating plates from being pinched. It needs to be bigger.

For this reason, it is necessary to increase the flow rate of the fluidizing gas to be supplied, and the pressure loss due to the increased capacity also increases, so the blower for supplying the fluidizing gas requires a large amount of power, and a large capacity dust collector etc. must be attached. However, there is a problem of high equipment costs.

Furthermore, the latter method merely vibrates the fluidized bed of the dryer to promote fluidization, and the only heating source for drying is the heat retained in the fluidizing gas, and a larger amount of fluid than the former method is used. It is not suitable for drying a large amount of powder and granular materials because it requires a large amount of gas. Therefore, it cannot be applied to fields that require a large amount of dry powder, such as coke ovens for steel manufacturing, and has poor versatility.

An object of the present invention is to promote heat transfer by vibrating the fluidized bed itself together with the heating plate or heating tube in addition to indirect heating using the heating plate or heating tube, thereby achieving efficient drying and providing heat transfer to the heating plate or heating tube. The purpose is to prevent the adhesion of powder and granules.

[Means and effects for solving the problems] The structure of the present invention is that in a fluidized bed dryer equipped with a fluidized bed having an inlet and a vibration generator for forcibly vibrating the fluidized bed, the top surface of the fluidized bed is A device with a plurality of heating plates or heating tubes installed vertically through which a heating fluid flows.Drying is carried out by heat transfer from both the fluidizing gas from the inlet and the heating plates or heating tubes, and the vibration of the heating plates or heating tubes. This prevents particles from adhering to the plate surface or pipe surface.

(Example) The present invention will be described below based on embodiments shown in the drawings.

FIG. 1 is a partially cutaway front view of a fluidized bed dryer according to the present invention;
2 is a sectional view taken along the line 1-1 m in FIG. 1, and FIG. 3 is a partially cutaway side view of the heating plate.

In the figure, l is the main body of the dryer, and an example is the powder supply duct 2.
One side and the other side are connected to the conveyor 3 for discharging the dried powder and granular material, and each communication part has two rotary feeders 4.5a for supply and discharge.

5b is provided.

Reference numeral 6 denotes a hot air supply pipe communicating with the lower part of the dryer main body 1, and downstream thereof a blower 7 and a heat exchanger 8 for generating hot air are arranged. Further, 9 is an exhaust pipe for discharging the gas supplied from the hot air supply pipe 6 into the dryer main body l.

A telescopic bellows pipe 10 is disposed at the connecting portion between the rotary feeders 4.5a, 5b, the hot air supply pipe 6, and the exhaust pipe 9 and the dryer main body 1.

Reference numeral 11 denotes a fluidized bed placed in the dryer main body 1, which has a large number of blowing ports 12 on the entire surface, and can supply hot air for drying and powder fluidization supplied from the hot air supply pipe 6 to the inside of the dryer main body 1. It is. The dryer main body l is supported by a spring 13, and the fluidized bed 1 is rotated at a predetermined frequency and amplitude.
1 is provided with a vibration generator 14 for vibrating.

Reference numeral 15 denotes a heating plate that is integrally installed on the fluidized bed 11, and as shown in FIG. A weir 16 is provided on the discharge side.

As shown in FIG. 3, this heating plate 15 is provided with a supply port 17 and a discharge port 18 at both ends through which a heating fluid such as steam flows in and out, and has a partition wall 19 inside so that the heating fluid passes through three passes. are placed. The supply port 17 and the discharge port 18 of each heating plate 15 communicate with a heating fluid supply header 20 and a discharge header 21 arranged outside the dryer main body 1 .

In the fluidized bed dryer having the above configuration, the powder and granular material from the supply duct 2 is cut out in a fixed amount by the supply rotary feeder 4, is evenly distributed between the heating plates 15, and flows onto the fluidized bed 11. At this time, the powder and granular material is transferred to the vibration generator 14.
The liquid is fluidized by the vibration of the fluidized bed 11 and the hot air from the hot air supply pipe 6, and is sequentially moved to the discharge side. Coarse particles that are difficult to fluidize accumulate at the bottom and similarly move sequentially to the discharge side due to the vibration of the fluidized bed 11.

Then, the powder and granules are heated by the heating plate 15 and dried by hot air, and those with a relatively small particle size pass over the weir 16 to the discharge rotary feeder 5a, and those with a relatively large particle size go to the discharge rotary feeder 5b. It falls and is conveyed from the conveyor 3 to complete the drying process.

During this drying process, the heating plate 15 vibrates together with the fluidized bed 11, so that even if the supplied powder contains moisture, the powder does not adhere to the heating plate 15.

Therefore, efficient drying is possible without a drop in the heat transfer coefficient from the heating plates ts, and the flow path area between each heating plate 15 is not reduced, so that the distance between adjacent heating plates 15 can be reduced. can be shortened, and there is no need to increase the area of the fluidized bed 11.

Therefore, since the device capacity can be downsized as described above, the cylinder velocity can be reduced to reduce the amount of hot air supplied for fluidization, and the power consumption of the blower 7 can be reduced.

In addition to the embodiments described above, a heating tube 22 shown in FIG. 4 may be used instead of the heating plate 15.

〔Effect of the invention〕

The fluidized bed dryer according to the present invention has the following effects depending on its configuration.

(a) Since drying is performed using a heating plate or heating tube and fluidization, a large amount of powder or granules can be dried in a short time.

(b) The heating plate or heating tube can vibrate together with the fluidized bed to prevent powder particles from adhering to the surface of the heating plate or heating tube, so the heat transfer efficiency from the heating plate or heating tube can be kept high, and each heating Since the spacing between the plates or heating tubes can be reduced, the capacity of the device can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view of a fluidized bed dryer according to the present invention;
Figure 2 is a sectional view taken along the line I-1 in Figure 1, Figure 3 is a cross-sectional view taken along the ■-■ line in Figure 2, and Figure 4 shows a heating tube that can be used in place of the heating plate. It is a front view. (11 Dryer body (6) Hot air supply pipe (7) Blower (8) Heat exchanger (9) Exhaust pipe (11
) Fluidized bed (12) Inlet (13) Spring (14)
41i generator (15) Heating plate (16) Weir
(17) Supply port (18) Non-exit (
22) Heating tube patent applicant Nippon Steel Corporation agent Masu Kodo (one idiot) Figure 1 Figure 2

Claims (1)

[Claims] 1. Equipped with a fluidized bed with an air inlet and placed inside the dryer body, and a vibration generator that forcibly vibrates the fluidized bed.
The fluidized bed dryer further comprises a plurality of heating plates or heating tubes erected at intervals on the upper surface of the fluidized bed, through which heating fluid supplied from the outside flows.