Gate valve for powder

Abstract

To provide a gate valve capable of purging even highly adhesive powder by introducing gas without leaving any powder behind.SOLUTION: In a gate valve, a disk-shaped plate 3a can move within a central space 2e defined by an upper case 1 and a lower case 2, where a gas introduction hole 1e is provided near a through-hole 2f of a rod 3b, a groove part 3d is provided on a peripheral side surface of the disk-shaped plate 3a, and when the difference between a height of the central space 2e and a thickness of the disk-shaped plate 3a is set to 0.5 mm or less, introduced gas efficiently blows away the powder to prevent the powder from being left behind.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a gate valve for blocking a flow path for powder that is highly adhesive and abrasive. [Background technology]

[0002] Gate valves, ball valves, butterfly valves, etc. are used for gases and liquids. When these valves are used to shut off the flow path for powder, the powder remains pressed into the gap between the valve body and the inner wall.When powders with different properties are manufactured in the same facility, if the powder remains attached before switching, it will be mixed into the powder product after switching, so it is time-consuming to remove the valve and clean it.

[0003] In food powder processing, the equipment is either removed and cleaned or the inside is washed with water to prevent the residual powder from spoiling, but the amount of residual powder is large and disposal is time-consuming.

[0004] If the powder is highly abrasive, the residual powder will rapidly wear out the valve body, requiring early replacement of the valve. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] 3 shows a plan view and a cross-sectional view of the gate valve 1. It comprises a valve body 2 with an opening 2f, a valve plate 3, and a shaft 5, and has a mechanism in which the valve plate 3 moves in the axial direction as the shaft 5 rotates. Summary of the Invention [Problem to be solved by the invention]

[0006] With the above valve, there is no way to discharge the powder that gets into the valve box 2 and gradually accumulates. The powder is pressed against the valve body 3 and arm 4, hardening and eventually making it impossible to operate. In addition, a strong layer of powder may form around the valve body 3.

[0007] The present invention aims to prevent powder from accumulating inside the valve body (case) even if it gets inside, and to completely eliminate adhesion or residue of powder by blowing away the powder on the circumferential part where the valve body is pressed to seal with a gas seal.

[0008] An embodiment of the present invention is shown in FIG. This powder gate valve consists of an upper case 1, a lower case 2, and a valve body 3. The upper case 1 has a central opening 1a and a connection flange portion 1c having a connection tap hole 1b. The lower case 2 has a central opening 2a and a connection flange 2c having connection tap holes 2b. An internal space 2e is provided inside the lower case 2, in which the disk-shaped plate 3a can slide, and the upper case 1 is shaped to cover this internal space 2e. Bolt holes 1d and 2d are provided to fasten the upper case 1 and the lower case 2 together, and they are integrated with bolts. The valve body 3 comprises a disk-shaped plate 3a, a rod 3b fastened thereto, and a grip 3c at the end of the rod. The rod 3b passes through a hole 2f in the lower case 2.

[0009] In this embodiment, the internal space 2e through which the disk-shaped plate 3a moves and the hole 2f through which the rod 3b passes are located on the lower case 2 side, but they may also be located on the upper case 1 side. Also, while a manual example has been shown, an air-operated or hydraulic cylinder may also be used. In that case, the rod of the cylinder becomes 3b, and the grip 3c becomes the cylinder.

[0010] The features of this invention are that the gas introduction hole 1e is provided in the upper case 1 near the through hole 2f of the rod 3b, that a groove 3d is provided on the side surface around the circumference of the disk-shaped plate 3a, and that the difference in height between the internal space 2e and the height (thickness) of the disk-shaped plate 3a is within 0.5 mm.

[0011] In the present invention, gas such as air is supplied from the outside to the internal space 2e through the gas inlet 1e, and the gas flow as shown in Figure 2 blows away and removes any powder that has invaded and accumulated in the internal space 2e, so the valve will not become inoperable.

[0012] Just before the disk-shaped plate 3a closes, the gas passes through the groove 3d and blows away the powder adhering to the periphery of the seal, preventing the formation of a solidified layer.

[0013] By keeping the difference in height between the internal space 2e and the disk-shaped plate 3a (thickness) within 0.5 mm, the gap between the internal space 2e and the disk-shaped plate 3a becomes smaller, the cross-sectional area through which the gas flows becomes smaller, and the gas flow rate becomes faster, thereby improving the effect of moving the powder. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is an isometric three-dimensional component drawing of the present invention. [Figure 2] FIG. 3 is a cross-sectional view showing the flow of gas. [Figure 3] 1A and 1B are a plan view and a cross-sectional view of the prior art document JP 2004-052886 A. Mode for carrying out the invention

[0015] Figure 1 shows an embodiment of the present invention. The gas introduction hole 1e may be located in the upper case 1 as shown in Figure 1, or in the lower case 2. However, it is necessary to locate it as close as possible to the through-hole 2f of the rod 3b.

[0016] The gas introduction hole 1e may have a small diameter of about 6 mm, and a gas pressure of about 200 KPa is sufficient. It is desirable to provide a small ball valve or the like in the gas inlet hole 1e so that gas is introduced only while the gate valve is in operation. [Explanation of symbols]

[0017] 1 Upper Case 1a Central opening 1b Connection tap hole 1c Connection flange 1d Bolt holes for fastening the upper and lower cases 1e Gas inlet 2 Lower case 2a Central opening 2b Connection tap hole (not shown as it is on the opposite side) 2c Connection flange 2d Bolt holes for fastening the upper and lower cases 2e: an internal space in which the valve body 3 can slide 2f: Hole through which rod 3b passes 3 Valve body 3a Disc-shaped plate 3b Rod 3c Grip

Claims

1. In a powder gate valve in which a disk-shaped plate 3a that moves back and forth linearly is placed in an internal space 2e provided between an upper case 1 and a lower case 2, and a rod 3b for moving it is provided through a rod-through hole 2f in the side wall of the lower case 2, a gas introduction hole 1e into the internal space 2e of the case is provided near the rod-through hole 2f.

2. 2. A powder gate valve according to claim 1, wherein a groove portion (3d) is provided on the peripheral side surface of the disk-shaped plate (3a).

3. 2. A gate valve for powder according to claim 1, wherein the difference in height between the internal space 2e and the disk-shaped plate 3a is within 0.5 mm.

Images