JPS6213073B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for classifying powder and granules to be treated into fine powder and coarse powder while suspending them in a primary gas in a housing containing a classification rotor. and a classification method in which the fine powder and granules are discharged out of the housing by gas, and a secondary gas for flotation sorting is made to flow upwardly into the floating downward flow path portion of the coarse powder and granules, and the method thereof. This invention relates to a classification device used for.

In the above method and apparatus, when looking at the particle size distribution of both the fine and coarse powder particles obtained by classification, some particles with particle sizes that should originally be included in the other particle are mixed in, and conventionally, It was thought that it was impossible to freely adjust such a particle size distribution state.

On the other hand, if you want to improve classification accuracy, for example,
It is possible to adjust the particle size distribution depending on the purpose of the obtained powder, such as when you want to obtain the desired particle size distribution by actively mixing substances that should originally be included in the other. There is a strong need, and the present invention aims to meet this need.

Next, embodiments of the present invention will be described with reference to illustrative drawings.

First to third gas supply paths 4, 5, and 6 connected to blowers 2 and 3 are communicated with the housing 1 forming the classification chamber, and an air intake path 8 is connected to the exhaust device 7. are communicated. A feeder 9 that supplies a fixed amount of powder and granular material to be treated is attached to the first gas supply path 4 so that the set supply amount thereof can be changed freely, and the powder and granular material is supplied into the housing 1 in a suspended state by gas. It is structured as follows. 2nd and 3rd
By providing a ratio control valve 10 at the branch point of the gas supply paths 5 and 6, the air volume ratio of both the supply paths 5 and 6 can be changed and set without changing the total air volume of both the supply paths 5 and 6, or without changing it too much. It is structured as follows. A solid-gas separator 11 and a valve 12 for adjusting the total air volume are provided in the intake passage 8, so that the amount of air supply and exhaust to the housing 1 can be adjusted. The structure is such that the separator 11 can collect the water.

As shown in FIGS. 2 and 3, inside the housing 1 is a classification rotor 14 that is rotated approximately around a vertical axis by a variable speed drive device 13, and a classification rotor 14 that is approximately concentric with the rotor 14. A cylindrical partition wall 15 that narrows downward is provided to form a first classification chamber 16 communicating with the first gas supply path 4, and
A second classification chamber 1 is provided below the cylindrical partition wall 15.
6', and this second classification chamber 16' has a discharge passage 17 for the coarse powder and granules at its lower part, and a rotary valve 18 is provided in the discharge passage 17 to prevent the inflow of outside air and remove the coarse powder. Place the side powder into the housing 1
It is designed so that it can be taken out. In addition, a large number of guide vanes 1 are provided around the entire circumference of the first classification chamber 16.
9 are arranged in parallel in an annular shape, and the gas from the second gas supply path 5 is discharged into the first classification chamber 16 in order to maintain the dispersed floating state of the powder and granules and to promote swirling flow by the rotor 14. It is structured as follows. Further, the third gas supply path 6 is communicated with the second classification chamber 16' below the partition wall 15, and the mixed fine powder particles are suspended in the channel portion 17a where the coarse powder particles float down. The gas is configured to flow upward for separation and return to the first classification chamber 16. Further, the air intake passage 8 is communicated with the interior of the classification rotor 14, so that the fine particles and gas that have passed between the vanes 14a of the classification rotor 14 are sucked into the air intake passage 8.

a computer 20 for adjusting the rotational speed N of the classification rotor 14 and the opening degree of the valve of the intake passage 8;
The computer 20 is configured with a calculation formula for calculating the rotation speed N of the classification rotor 14 based on the classification reference particle size d, the density ρs of the granular material to be processed, and the air flow rate Q into the intake passage. ,In other words, an input mechanism 22 is provided for manually setting the classification reference particle size d, the amount of air flowing into the intake passage Q, and the density ρs of the powder and granular material to be processed into the calculation mechanism 21, and , a mechanism 23 that automatically controls the drive device 13 to maintain the rotational speed N of the classification rotor 14 at the value calculated by the calculation mechanism 21, and a valve 12 to maintain the inflow air volume Q set by the input mechanism 22. A mechanism 24 for automatic control is provided.

The operation mechanism 25 of the ratio control valve 10 is linked to the input mechanism 22, and the air volume ratio of the second and third gas supply paths 5 and 6 can be artificially set using the input mechanism 22. There is.

Next, how to use and operate the above-mentioned classification device will be explained.

The input mechanism 22 simply inputs the desired classification standard particle size d, the density ρs of the target powder, and the air exhaust device 7.
Simply by artificially giving a signal instructing the inflow air volume Q to the intake passage 8 which is appropriate in terms of performance, the rotational speed N of the classification rotor 14 and the opening degree of the valve 12 are automatically set and maintained at predetermined values. Therefore, the desired powder classification can be carried out reliably. Furthermore, as shown in Fig. 4, when the powder to be processed with the particle size distribution shown by the solid line A is classified using the classification standard particle size d under certain conditions, the particle size distribution of the fine powder is As shown by the dotted line B, and the particle size distribution of the coarse side powder and granules is the dashed line C.
If the ratio control valve 10 is operated to increase the air volume of the third gas supply path 6, a portion of the dotted line B and the dashed-dotted line C will become as shown in the dotted line _B1 and the dashed-dotted line _C1. When the air volume of the third gas supply path 6 is reduced, parts of the dotted line B and the dashed-dotted line C are deformed as shown by the dotted line B ₂ and the dashed-dotted line C ₂ . In other words, by operating the ratio control valve 10, the particle size distribution of fine and coarse particles can be arbitrarily changed and set.

Incidentally, in order to connect the first gas supply path 4 to the first classification chamber 16, as shown in FIG. good. In addition, in order to change the flow rate ratio of the primary gas and the secondary gas, various configuration changes may be made, such as configuring a throttle valve provided in one or both of the flow path portions to be operated independently or in conjunction with each other. These are collectively referred to as the valve mechanism 10. When supplying powder or granules in a suspended state using part or all of the primary gas, the weight of the powder per unit amount of gas in the supply path 4 is maintained approximately constant in order to perform good classification. For example, a configuration that adjusts the supply amount of powder or granular material by detecting changes in the air volume of the supply path 4 can also be used.
These are collectively referred to as a powder supply adjustment mechanism 9.

In order to change the rotation speed N of the classification rotor 14, various configuration changes are possible, such as interposing various speed change mechanisms between the constant speed drive device 13 and the classification rotor 14. classification rotor 14
But that's fine.

The valve 12 of the intake passage 8 can be omitted or replaced with a suitable fixed throttle valve, and in short, it is sufficient if the configuration is such that the amount of air flowing into the intake passage 8 can be maintained substantially constant.

The signal inputted to the computer 20 to calculate the rotation speed N of the classification rotor 14 may be only the classification standard particle size d, or only the classification standard particle size d and the air flow rate Q into the intake passage 8. In the former case, the calculation formula stored in the computer 20 is N=
Ka・1/d (Ka: constant), and the memory calculation formula in the latter case is Therefore, the calculation formula actually stored in the computer 20 can be converted in various ways. A microcomputer is sufficient for the computer 20, but its specific configuration can be changed in various ways, and furthermore, the computer 20 may be omitted. Book 1
The form of the classification apparatus used in carrying out the classification method according to the invention is not limited, as long as it is equipped with the minimum functions necessary to carry out the method.

In summary, the first invention supplies the powder or granules to be treated suspended in the primary gas into the first classification chamber of the housing in which the classification rotor is installed, and , blowing and supplying a secondary gas for classifying the powder and granules mixed into the primary gas into fine powder and coarse particles; While discharging the coarse powder to the outside of the housing, the coarse powder is lowered to the lower second classification chamber, and further into the second classification chamber, the floating down flow of the coarse powder is acted on, and the floating of the coarse powder is reduced. In a classification method that supplies a tertiary gas that releases fine particles adhering to coarse particles contained in the downward flow and causes them to flow upward, changing the air volume ratio between the secondary gas and the tertiary gas. It is characterized by

That is, in the classification in the first classification chamber equipped with a classification rotor, it goes without saying that the coarse powder and the fine powder are classified, but in this first classification chamber, the peripheral part Since the secondary gas is supplied at a high speed from The adhesion of the particles is released and the particles are efficiently made into single particles. Then, the particles that adhere to the coarse powder and granules come into contact with the tertiary gas in the second classification chamber, where they are also subjected to classification action, and are further divided into the coarse and fine particles. Classification is performed. In this way, the degree of classification is extremely improved, but in the method of the present invention, the air volume ratio between the secondary gas and the tertiary gas is changed, so for example, if the air volume ratio on the secondary gas side is increased, , it is possible to obtain a powder with a high proportion of fine particles in the fine powder by promoting the single particleization of the fine powder as much as possible, and conversely, by increasing the air flow ratio of the tertiary gas, the fine particles mixed in the coarse powder can be obtained. Powder with the minimum amount of side powder particles can be obtained, and it can be used to ensure optimal classification for each individual case, such as when highly accurate classification or a specific particle size distribution is required. It has now become possible to provide a classification method that is easy to operate, easy to operate, and extremely convenient overall.

Further, in the classification device according to the second invention, the housing constituting the first classification chamber in which the classification rotor is housed and the second classification chamber provided below the first classification chamber, A first gas supply path for the primary gas that transports the powder and granules, and a first classification chamber in which the powder and granules supplied to the first classification chamber are swirled and flowed in a dispersed suspended state to be separated into fine powder and coarse powder. It acts on the second gas supply path of the secondary gas for classifying the secondary gas and the floating downward flow of the coarse powder and granular material that has flowed down from the first classification chamber to the second classification chamber side, and adheres to the coarse powder and granular material. Each supply path is connected to a third gas supply path for a tertiary gas for liberating the fine powder and granules, and the first classification chamber is provided with the classified fine powder to the outside of the housing. The second classification chamber is provided with a discharge path for the coarse powder and granular material, and second and third gas supply paths for supplying the secondary gas and the tertiary gas, respectively. is composed of branch pipes connected to a common air source, and the flow path area is changed at the branch point so that as the area of one flow path increases, the area of the other flow path decreases. The present invention is characterized by being provided with a valve mechanism that can reversely change the flow rate ratio of the secondary gas and the tertiary gas flowing through both gas supply paths.

That is, as detailed in the explanation of the above method, the particle size distribution of the classified material can be arbitrarily and easily and reliably adjusted by adjusting the valve mechanism 10, and moreover, part or all of the secondary gas can be By discharging it around the circumference of the rotor 14, the contradictory changes in the amounts of secondary gas and tertiary gas have a mutual effect on the above particle size distribution adjustment, making it possible to adjust the particle size distribution over a wide range and sharply. .

[Brief explanation of the drawing]

The drawings show an embodiment of the classification method and classification apparatus according to the present invention, and FIG. 1 is a flow sheet, FIG. 2 is a longitudinal cross-sectional view of the main parts, FIG. 3 is a cross-sectional view of the main parts, and FIG. 4 is a cross-sectional view of the main parts. A graph showing the particle size distribution and FIG. 5 are longitudinal cross-sectional views of main parts showing another example. 1... Housing, 4, 5, 6... Supply path, 8
...Intake path, 9...Powder supply adjustment device, 10...
...Valve mechanism, 14...Classifying rotor, 16...First classification chamber, 16'...Second classification chamber, 17, 17a...
Exhaust channel.

Claims (1)

[Claims] 1. Particles to be treated are supplied in a state suspended in primary gas into the first classification chamber 16 of the housing 1 in which the classification rotor 14 is installed, and the first classification chamber 16 A secondary gas is blown and supplied to classify the powder mixed in the primary gas into fine powder and coarse powder, and the fine powder is transformed into a gas. , the coarse powder is discharged to the outside of the housing 1, and the coarse powder is transferred to the lower second classification chamber 1.
6' side, and further the second classification chamber 1
6' is a tertiary gas that acts on the floating downward flow of the coarse powder and granules to liberate the fine particles adhering to the coarse powder contained in the floating downward flow and causes them to flow upward. A classification method for supplying gas, the classification method comprising changing the air volume ratio between the secondary gas and the tertiary gas. 2. Supplying the powder or granules to be treated into the housing 1 in a suspended state dispersed by at least a portion of the primary gas, and maintaining the weight of the powder or granules per unit amount of gas in the supply substantially constant. A classification method according to claim 1, characterized in that: 3 First classification chamber 16 in which the classification rotor 14 is housed
and a second classification chamber 16' provided below the first classification chamber 16. A second gas which is a secondary gas for swirling the powder and granules supplied to the supply path 4 and the first classification chamber 16 in a dispersed floating state and classifying them into fine powder and coarse powder. Supply channel 5 and first classification chamber 16
A third gas of the tertiary gas for acting on the suspended downward flow of the coarse powder and granules flowing down from the to the second classification chamber 16' side and liberating the fine powder and granules adhering to the coarse powder and granules. The supply channels 4, 5, and 6 are connected to the supply channel 6, and the first classification chamber 16 is connected to an intake channel 8 for leading out the classified fine powder to the outside of the housing 1. The second classification chamber 16' is provided with a discharge passage 17 for coarse powder and granules, and further has second and third passages for supplying the secondary gas and tertiary gas, respectively.
The gas supply paths 5 and 6 are configured by branch pipes connected to a common air blowing source, and at the branch points,
The flow rate ratio of the secondary gas and the tertiary gas flowing through both gas supply channels 5 and 6 is reversed by changing the channel area so that as the channel area of one channel increases, the channel area of the other channel decreases. A classification device equipped with a changeable valve mechanism 10. 4 Primary gas supply path 4 into which the powder and granular material is mixed
The powder or granule is configured to be dispersed and suspended in at least a portion of the primary gas, and the weight of the powder or granule per unit amount of gas in the powder or granule supply path 4 is maintained approximately constant. 4. The device according to claim 3, characterized in that a supply adjustment mechanism 9 is provided.