JPH019660Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a classifier that separates granular raw materials into coarse particles and fine particles.

The applicant previously filed a patent application for ``Classifier'' (Patent Application 1983-37615).
has been applied for. The application discloses that a classification screen is formed into a cylindrical shape for the purpose of improving strength and rigidity and increasing the effective passage area, and furthermore, an air purge pipe is provided in the screen so that its openings face each other, and the classification screen is operated by a driving device. It is constructed in such a way that either the screen or the air purge tube is moved relative to the other while air is injected from the opening of the air purge tube onto the surface of the classification screen to prevent clogging of the mesh. be.

Such a classifier is as shown in FIGS. 1 and 2, and the upper part 1a of the casing 1 has a cylindrical shape, and the lower part 1 has a cylindrical shape.
b are each formed into an inverted conical shape, and the upper end opening of the casing upper part 1a is covered with a cover plate 3. Partition walls 4 and 5 are provided at the upper part of the casing upper part 1a and at the boundary between the upper part 1a and the casing lower part 1b so as to cross the internal space. A classification chamber 7 is placed between the partition walls 4 and 5,
Further, coarse particle chambers 8 are defined in the conical lower part 1b of the casing below the lower partition wall 5. A raw material input port 9 that opens upward is provided in the center of the lid plate 3, and a particulate discharge port 10 is provided in the center of the lower partition wall 5 and is led out to the outside through a pipe body, which is connected to a cyclone or a blower, for example. A coarse particle discharge port 11 is provided at the lower end of the coarse particle chamber 8, and a rotary valve or the like is installed therein.

A plurality of classification screens 13 are vertically arranged radially around the periphery of the classification chamber 7. The classification screen 13
The upper holder 14 is rotatable through the upper partition wall 4, the lower holder 15 is rotatable through the lower partition wall 5, and the upper and lower ends are provided between the upper and lower holders 14, 15. A cylindrical screen 17 of a desired mesh is bound with a band 16 to the part facing the interior of the room, and a small-diameter connecting rod 18 is installed vertically in the center of the upper and lower holders 14, 15, so that the holder 14, 15 is fixedly integrated. The upper holder 14 has a raw material supply port 2 that opens outward in the radial direction in a portion facing the raw material input chamber 16.
7 is provided.

Reference numeral 19 indicates a sealing device provided on the upper and lower partition walls 4 and 5, and 12 indicates a conical raw material distributor provided on the upper partition plate 4.

A drive shaft 20 for driving each of the classification screens 13 is installed on the cover plate 3, and these drive shafts are connected to the case 21.
It is supported by a bearing 22 inside. A sprocket 23 is provided at the upper end of the shaft extension and is driven by a chain, and one of the shafts is driven by a drive wheel 24 to rotate the classification screen 13.

On the outside of each classification screen 13, an air purge pipe 25 with a pressurized air outlet opening in the direction of the screen 17 is arranged so as to extend along the entire length of the screen 17, and the pipe 26 is a communicating pipe connected to an external high-pressure air source. Connected.

In the above process, the raw material is inputted from the raw material input port 9, the raw material is distributed radially from the center by the distributor 12, and is supplied to the classification screen 13 from the raw material supply port 27. The fine particles that pass through the mesh of the screen 17 are guided to the fine particle outlet 10, and the coarse particles that do not pass through the mesh are guided to the coarse particle outlet 11 and collected.

The screen 17 rotates as described above, and the air purge pipe 25 blows air onto the surface of the screen 17 to prevent clogging of the mesh.

However, in the above device, the raw material supply chamber 6 and the classification chamber 7 are sealed by a sealing device 19;
There is a drawback that fine particles in the raw material enter the seal portion 28, causing wear on the sliding surface thereof and shortening the life of the seal device 19.

In view of the current situation as described above, the inventor of the present application conducted intensive research and found that if a semi-sealed chamber is provided near the sealing portion 28 and air is supplied to the sealed chamber and the airflow scatters the particles, the particles will be able to reach the sealing surface. The present application was completed based on the knowledge that the sealing device 19 can be prevented from entering and damage to the sealing device 19 can be prevented.

That is, in the present application, a cylindrical casing with a funnel-shaped bottom is divided into a plurality of chambers by partition walls, and a cylindrical classification screen is rotatably installed vertically in the classification chamber formed in the middle part of the casing. In a classifier equipped with a sealing device in the penetration part of the partition, an air supply port is opened near the sealing device and on the outer periphery of the holder in the classification screen, and a slit is opened between the air supply port and the outer periphery of the holder on the opposite side of the sealing device. This is an air seal classifier characterized by having a chamber.

First, in FIGS. 3 and 4, 30 is a semi-closed air chamber, which is provided in the upper partition wall 4 and the lower partition wall 5, respectively, and the former is referred to as an upper air chamber 30a and the latter as a lower air chamber 30b.

First, the structure of the upper air chamber 30a will be described. The upper air chamber 30a has an annular shape and an inverted L-shaped cross section. It is formed in a space surrounded by a ring member 31 having a shape. A branch duct 32 for guiding air there is connected to the upper air chamber 30a, and a ring-shaped slit 33 is formed above and between the upper holder 14 and the entire circumference. Further, the branch duct 32 is connected to an air supply duct 34 communicating with a high-pressure air source, so that air is supplied to the upper air chamber 30a.

Next, regarding the lower air chamber 30b, its configuration is the same as that of the upper air chamber 30a.

In this embodiment, a plurality of classification screens 13 are installed radially within the casing 1, and an air chamber 30 is provided for each, and furthermore, in the upper air chamber 30a, the bottom surface 36 of the raw material supply port 27 is connected to a ring member 31. It is formed at approximately the same height as the upper surface 37, and is configured so that the air supplied to the upper air chamber 30a is blown out into the raw material input chamber 6 through the slit 33.

A valve 38 is installed in the air supply duct 34 and is used to adjust the amount of air supplied to the air chamber 30. Next, FIG. 6 shows another embodiment of the air chamber 30, and the air chamber 30 may be formed in a spiral shape as shown in the figure.

Next, FIG. 7 shows another embodiment of a method of supplying air to the air chamber 30. This embodiment is an example in which pipes 39 are arranged independently as means for supplying air to each air chamber 30, and these pipes are communicated with a high-pressure air source.

Furthermore, in the embodiment shown in FIG. 7, a cyclone and a blower (not shown) are installed at the particulate discharge port 10.
When operating this device by connecting the casing 1, the inside of the casing 1 becomes negative pressure, so the pipe 39 is simply opened to the atmosphere without connecting it to an air source, and air is blown out from the slit 33 shown in Fig. 4. be able to.

Further, in this embodiment, an example is shown in which the upper air chamber 30a is also installed under the sealing device 19, but this allows particles floating in the classification chamber to be contained in the chamber 3.
Infiltration into 0a can also be prevented. Although not shown, the same applies to the lower air chamber 30b, and especially in the case of FIG. 7, a bearing 35 is interposed therebetween.

Next, the embodiment shown in FIGS. 9 and 10 is an example in which the bottom surface 36 of the raw material supply port 27 is formed at the same height as the upper end of the sealing device 19. Even if there is infiltration, raw material supply port 2
7 to the classification screen 13.

Furthermore, FIG. 11 shows an embodiment in which the present invention is applied to a multi-stage classifier.

The present invention is constructed as described above, and the air supplied to the air chamber passes through the slit and is ejected into the classification screen via the raw material supply chamber or the raw material supply port, so that particles do not enter the sealing part. This prevents damage to the sealing device.

[Brief explanation of the drawing]

Figure 1 is a front sectional view of the classifier by the applicant;
Figure 2 is an enlarged view of part A in Figure 1, Figure 3 is a front sectional view of the classifier according to the present application, Figure 4 is an enlarged view of part B in Figure 3, and Figure 5 is Figure 4, 5-5. 6 is another embodiment of the air chamber, FIG. 7 is another embodiment of the air supply method, FIG. 8 is an enlarged view of section D in FIG. 7, and FIG.
The figure shows another embodiment of the air chamber, FIG. 10 is a sectional view taken along line 10-10 of FIG. 9, and FIG. 11 is a diagram of an embodiment in which the present invention is applied to a multi-stage classifier. In the drawing, 30 is an air chamber, 32 is a branch duct,
33 represents a slit, and 34 represents an air supply duct.

Claims (1)

[Scope of utility model registration request] A cylindrical casing with a funnel-shaped bottom is divided into a plurality of chambers by partition walls, and a cylindrical classification screen is rotatably installed vertically in the classification chamber formed in the middle part of the casing, and a penetrating portion in the partition wall is used. In a classifier equipped with a sealing device, an air chamber is provided with an air supply port in the vicinity of the sealing device and on the outer periphery of the holder in the classification screen, and an air chamber formed by opening a slit between the air supply port and the outer periphery of the holder on the opposite side of the sealing device. This air seal classifier is characterized by: