JPS5852157B2 - Multistage fluidized bed cooling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a multi-stage fluidized bed cooling device that includes a plurality of fluidized beds connected sequentially through material passages and sequentially cools granular material by feeding cooling gas into the material in each fluidized bed. Regarding.

This multi-stage fluidized bed cooling device sequentially feeds granular material onto the perforated plate forming the bottom plate of each fluidized bed, and at the same time feeds cooling gas (air) from below the perforated plate. For example, Approximately 140℃ when making koji for soy sauce brewing.
It is used in the process of rapidly cooling roasted barley to below 40℃.

First, a conventional multistage fluidized bed cooling device will be explained with reference to FIG.

FIG. 1 illustrates the case of a two-stage fluidized bed, which includes an upper fluidized bed 12 and a lower fluidized bed 14.

The granular material 16 is fed into the upper fluidized bed from a material feed rotary valve 18 through an inlet 20 provided at the top of the upper fluidized bed 12 .

The material supplied into the upper fluidized bed flows down the material passage 22 and is fed onto the bottom plate 24.

The bottom plate 24 is formed of a single perforated plate.

The material flowed over the bottom plate 24 of the upper fluidized bed 12 is fed into the lower fluidized bed 14 through a material passage 26 connected to the downstream end of the bottom plate and onto the bottom plate 28 thereof.

The bottom plate is also formed of a single perforated plate, and the material flowing on the bottom plate flows down to the outlet 32 through the material passage 30 connected thereto, and is discharged to the outside from the discharge rotary valve 34.

On the other hand, cooling gas such as air is sent from the air supply port 36 connected to the lower fluidized bed 14 to the lower side of the porous bottom plate 28 of the lower fluidized bed.

The cooling gas is fed through the bottom plate 28 into the material on the bottom plate and reaches the bottom side of the bottom plate 24 of the upper fluidized bed 12 after cooling the material.

Similarly, it is passed through the bottom plate 24 and into the material above the plate hole to cool it.

The cooling gas that has passed through each fluidized bed is exhausted from the exhaust port 38.

Such a conventional multistage fluidized cooling device has a structure in which the upper fluidized bed is cooled by the cooling gas that has passed through the lower fluidized bed.
Furthermore, since the bottom plate of each fluidized bed is formed of a single perforated plate, there are the following drawbacks.

(1) Since the cooling gas is used continuously from the lower fluidized bed to the upper fluidized bed, the pressure decreases as it goes to the top.
A large pressure difference develops between the top and bottom.

For this reason, the cooling gas bypasses the material passage 26 rather than passing through the bottom plate (perforated plate) with high resistance, and the flow of the material in the material passage becomes uneven, causing problems in operation.

(ii) Since the bottom plate was formed from a single perforated plate,
There is a lot of blown up particulate material, making it difficult to make the fluid state uniform.

For reasons of (110 above, revised 1) and (il), operation is difficult, especially at startup.

4V) The total height of the system, in which the upper and lower fluidized beds are stacked one on top of the other, increases, resulting in high construction costs.

An object of the present invention is to eliminate the drawbacks of the prior art and provide a multistage fluidized bed cooling device that can efficiently cool granular materials such as powder particles with simple operations.

In particular, in the multistage fluidized bed cooling device of the present invention, even when rapidly cooling the material, it is possible to efficiently cool the material to a temperature approximately equal to that of the cooling gas supply source.

In the present invention, each fluidized bed is configured by a partition wall whose lower end is submerged in the material, a bottom plate provided with multiple perforated plates, and a partition plate that restricts the outflow of the material, and the lower part of the bottom plate is used as a blowing chamber. This system converts the dynamic pressure of the cooling gas from the blower duct connected to the common blower into static pressure instead of rectifying it, and uniformly cools the entire surface of the fluidized bed bottom plate. The feature is that by installing each fluidized bed independently, the pressure difference between each fluidized bed is eliminated and air is reliably supplied to each fluidized bed.

Hereinafter, the present invention will be explained in detail with reference to FIGS. 2 to 6.

FIGS. 2 and 3 are diagrams showing the structure of an embodiment of the multistage fluidized bed cooling device of the present invention.

This embodiment has four fluidized beds 52A, 52B.

52C2 and 52D, the granular material 54 is supplied from the material inlet 56 provided at the top of the first stage fluidized bed 52A, and is cooled while flowing through each fluidized bed. After that, the material exits from the material outlet 58.

On the other hand, as shown in FIG. 2, the cooling gas is sucked by a blower 60 from a cooling gas intake 62 through each fluidized bed to a cooling gas outlet 64.

In FIG. 2, reference number 66 indicates a dust collector.

In FIG. 3, each fluidized bed 52 A t 52 B .

Bottom plates 68A, 68B, 68C and 68D are provided within 52C and 52D to allow the material to flow.

Each bottom plate is formed of a plurality of (two in the illustrated example) perforated plates.

A vertical material passage 70A is provided between the material inlet 56 and the first stage bottom plate 68A, and a material passage 70B is provided between each fluidized bed to connect the bottom plates.

70C and 70D are provided.

Further, a material passage 70B is provided between the bottom plate 68D at the last stage and the material outlet 58.

Further, the fluidized bed 52A and the fluidized bed 52B are partitioned by a partition wall 91 whose lower end is submerged in the material, and the fluidized bed 52C
and the fluidized bed 52D are separated by a partition wall 93.

The downstream end of each bottom plate is a partition plate 72A for restricting the outflow of granular material and ensuring a predetermined material flow state.

72B, 72C and 72D are provided.

As shown in FIG. 3, each fluidized bed is provided with independent supply lowers 4A, 74B, 74C and 74D and exhaust lowers A, 76B, 76C and 76D.

The cooling gas taken in from the air supply intake port 62 passes through the air supply main duct 78 and then branches from the air supply branch duct 80AJOB.

Each fluidized bed is separately supplied from each air inlet through 80C and 80D.

The gas after cooling each fluidized bed is separately exhausted from exhaust branch ducts 82A, 82B, 82C, and 82D connected to the respective exhaust ports, and is led to the cooling gas exhaust port 64 through the main exhaust duct 84.

Furthermore, in each fluidized bed, the ventilation portion below the bottom plate is a chamber 86A having a desired volume.

86B, 86C and 86D.

Note that a damper 88 for adjusting the air flow rate is provided in each of the air supply branch ducts 80A to 80D and each of the exhaust branch ducts l-82A to 82D.

Since the multistage fluidized bed cooling device according to an embodiment of the present invention has the structure described above, the kinetic energy (dynamic pressure) of the cooling gas introduced from the air supply port into each fluidized bed is transmitted to each chamber 86A to 86D. The pressure is converted into static pressure, and the flow is rectified while passing through the plurality of perforated plates forming each of the bottom plates 68A to 68D, further promoting the conversion from dynamic pressure to static pressure.

Therefore, the cooling gas can be uniformly fed into the flowing granular material and uniformly and effectively cooled over the entire surface of the bottom plate.

Furthermore, since the supply and exhaust of cooling gas is carried out along an independent thread path for each fluidized bed, there is no pressure difference between each fluidized bed, and cooling gas can be reliably supplied to each fluidized bed. .

Further, the problem of bypassing the cooling gas through the material passage between each fluidized bed is eliminated.

The multi-stage fluidized bed cooling apparatus as illustrated in FIGS. 2 and 3 is used, for example, for cooling wheat or roasted barley for making koji for soy sauce brewing.

This roasted barley has a temperature of about 140°C, but in order to make good koji, it is necessary to rapidly cool it to below 40°C.

This is because the rapid cooling makes it possible to crush the wheat into uniform grain size, and the action of koji makes the starch and protein in the wheat easily digestible.

FIG. 4 is a diagram showing the structure of another embodiment of the multistage fluidized bed cooling device of the present invention, and the reference numbers in FIG. 4 that are the same as those in FIGS. 2 and 3 are the same. Or the corresponding part is displayed.

The one in FIG. 4 has three fluidized beds 52A, 52B and 52.
C, and each fluidized bed is arranged in a stepwise manner connected to each other.

Other structures are substantially the same as the embodiments of FIGS. 2 and 3, and the effects thereof are also substantially the same.

However, the horizontal arrangement shown in FIG. 4 allows the height of the entire device to be minimized, which is more advantageous in terms of securing an installation location and reducing construction costs.

FIG. 5 shows an example of actual measurement of the wind speed distribution of the cooling gas on the plate thicknesses 68A to 68D of each fluidized bed in the embodiments shown in FIGS. 2 and 3.

Each numerical value in this figure represents the wind speed at one position in m7 seconds, and it can be seen that according to the device of the present invention, the wind speed is made uniform over the entire surface of the bottom plate.

Moreover, FIG. 6 shows the measurement results of changes in the temperature of the granular material (wheat) and the temperature of the cooling gas (outside air) in the embodiments shown in FIGS. 2 and 3.

In the figure, the solid line A shows the temperature change of wheat, and the dotted line B shows the temperature change of the cooling gas (air) of each fluidized bed.

Even with air at 30°C, wheat is smoothly cooled from 140°C to 38°C.

That is, according to the present invention, even when the outside temperature is 30°C in summer, wheat at 140°C can be stably, reliably and effectively heated to 40°C.
It can be cooled to below ℃.

According to the embodiments of the present invention as described above, the following effects can be obtained.

(i) The wind speed distribution on the bottom plate of each fluidized bed can be made uniform.

(11) Cooling gas does not bypass the material passage and blow through.

010 Even when the material layer is thin, such as at the start of operation, the material flows smoothly and its supply becomes smooth.

(IV) Since the cooling gas is supplied independently to each fluidized bed, the cooling effect is large and rapid cooling can be easily performed.

(v) Since it is not necessary to arrange each fluidized bed vertically,
The installation area can be arbitrarily adjusted according to the installation space.

As is clear from the above explanation, according to the present invention? f. A multistage fluidized bed cooling device is provided which can efficiently cool granular materials and is easy to operate.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the arrangement of a conventional multistage fluidized bed cooling device, Fig. 2 is a flowchart showing an embodiment of the multistage fluidized bed cooling device of the present invention, and Fig. 3 is a multistage fluidized bed cooling of Fig. 2. FIG. 4 is a vertical sectional view showing the main parts of the apparatus, FIG. 4 is a longitudinal sectional view showing the main parts of another embodiment of the multistage fluidized bed cooling apparatus of the present invention, and FIG. Explanatory diagram showing an example of wind speed distribution measurement, No. 6
The figure is a chart showing an example of measurement of the temperature change of the material (wheat) and the temperature change of the cooling gas (air) using the apparatus of FIG. 3. 52A to 52D...Fluidized bed, 54...
Granular material, 60...Blower, 68A to 68D.
...Bottom plate, 72A-72D...Partition plate,
74A-74D・・・Air supply port, 76A-76D・
...Exhaust port, 86A-86D...Chamber 81.93...Partition wall.

Claims (1)

[Claims] 1. A device comprising a plurality of fluidized beds sequentially connected through a material passage,
In a multi-stage fluidized bed cooling device configured to send cooling gas to the material in each fluidized bed, each fluidized bed has a bottom plate formed by stacking perforated plates, and a lower end provided above the bottom plate that is connected to the material. A ventilation chamber formed independently below the bottom plate of each fluidized bed, comprising a partition wall recessed therein and a partition plate provided at the downstream end of the bottom plate to restrict outflow of the material. A multi-stage fluidized bed cooling system comprising: an air supply port for cooling gas supplied by a common blower formed in each of these chambers; and a cooling gas exhaust port formed above each of the fluidized beds. Device.