JPS62242184A - Cleaning method for valve plate whole surface seal type gate valve - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for cleaning a gate valve installed in a fluid passage through which powder or slurry flows.

BACKGROUND OF THE INVENTION Conventionally, a gate valve (411) installed in a fluid passage, for example, as shown in FIG.
2) to raise and lower the valve body (451t-
It opens and closes, and when the valve body ■ is lowered and the gate valve υ is completely closed, the entire valve body is sealed, but when the valve body is tapered and close to the closing surface. Since it has a concave portion, when the gate valve ←l is in the open state with the valve body (2) in the raised position, and when the valve body (No.) is being raised and lowered, the fluid passage decoy and the inside of the valve box portion communicate with each other, and fluid enters the inside of the valve box portion. Therefore, if the fluid is powder or slurry containing solid particles, the solid particles entering the valve box will impair the lifting and lowering of the valve element (1) and its function, making the gate valve I unusable.

Therefore, the gate valve G shown in Fig. 5 (at (bl)
υ is adopted. This gate valve is constructed by raising and lowering a valve plate via a valve body using a cylinder to create a fluid passage.
The valve plate (b) is provided with a valve hole at its lower part, and in the raised position of the valve plate (b), the fluid passage communicates through the valve hole to form a gate valve (6). is in the open state, and in the lowered position, the fluid passage (to) is blocked by the upper part of the valve plate (b), and the gate valve (2) is in the closed state. Fluid passage Mf in the upper part of the valve box (57a) and the lower part of the valve box (57b)
Ring seal branches are provided in pressure contact with both sides of the valve plate (2) in the area (57a x 57b) to prevent fluid from entering the valve box (57a x 57b). Further, when the valve plate (b) is raised and lowered, solid particles that enter the lower part of the valve box (57b) through the valve hole and settle down are discharged from the cleaning port as appropriate.

Problems to be Solved by the Invention In gate valves used for slurry containing powder or granules, a particular problem is wear of the valve plate and sealing material, and in the case of the above conventional example, As shown in FIG. 6(a), when the valve plate moves downward from open to closed, the solid material inside the valve hole is between the upper end of the valve hole (4) and the ring seal (end). Particles get stuck and cause significant wear and damage to the ring seal. In addition, the same is true for the case where the lower part of the valve hole (■ when the valve plate in BL rises) intersects with the ring seal (Fig. The wear of the gate valve (B) is severe, and the number of effective opening and closing operations of the gate valve (B) is extremely small with occasional cleaning of the valve box. No action was taken to do so.

The present invention solves the above problems and aims to provide a method for cleaning a gate valve that can reduce damage to the valve plate and seal plate.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a seal plate that is pressed against both sides of the valve plate when the gate valve is opened and closed, and during opening and closing operations. When cleaning a gate valve with a full seal on the valve plate that always isolates the valve hole from the inside of the valve box,
Cleaning fluid is forced into the valve hole from inside the valve box through a small hole provided in the valve plate that communicates the inside of the valve box with the valve hole.

Function: In the above method, the solid particles in the valve hole are forced out into the fluid passage by pressurizing the cleaning fluid, diluting the concentration of solid particles and making it easier for the particles to move, and the cleaning fluid also promotes the flow of the solid particles to close the seal plate. This reduces the possibility of solid particles getting caught in the valve plate, thereby significantly reducing wear and damage to the seal plate and valve plate.

EXAMPLE An example of the present invention will be described below based on the drawings. 1st
Figure (aHb) is a side view of a gate valve showing one embodiment of the present invention, Figure 2 is a sectional view taken along line II shown in Figure 1 (at), and Figure 3 is a front view of a seal plate. In Figures 1 to 3, (
2) is the main body of a gate valve (2) that is installed on the side of the pipe through which the liquid slurry containing solid particles flows, and this main body (2) is connected to the upstream pipe (13A) through the inlet side flange Q4. A first frame body αη having an inlet side fluid passageway (15A) connected to the rear end of the inlet side fluid passageway (15A) and forming a valve box αot around the rear end of the inlet side fluid passageway (15A), and a first frame body αη formed on the back side of the first frame body αη It has an outlet fluid passageway (15B) that is attached to the inlet fluid passageway (15B) and is continuous with the inlet fluid passageway (15A), and is connected to the outlet side fluid passageway (15B) through an outlet side 7 flange (toward) at the rear end of the outlet side fluid passageway (15B). Downstream pipe line (1
3B) is connected to the second frame body (1 value) and a lid body (1) attached to the top surface of the valve box αG. A movably housed rectangular plate-shaped valve plate, which has a closing part (21a) f for blocking the fluid passage (15AX15B) at its lower part, and a fluid passage (15A) (15B) t for communicating fluid at its upper part. Passage (1
5AX15B) has a valve hole (21b) with the same inner diameter. The opening is a small hole drilled from the top surface of the valve plate to the top of the valve hole (21b), and is located inside the valve box αQ and the valve hole (21b).
(b) is communicated with the valve hole (21b), and the cleaning liquid (21) in the valve box (21) is forced into the valve hole (21b) through this small hole (A).

In addition, (C) is a valve stem whose lower end is connected to the upper part of the valve plate, which extends upward through the lid body (1), and whose upper end has a valve stem (C) that moves up and down. A valve opening/closing device (not shown) is provided. Valve plate by this opening/closing device? υ is slid up and down to open and close this gate valve circle. Further, (to) is a ring seal interposed around the valve stem (c) penetration part of the lid body. e! B@ is a sealing plate made of, for example, tetrafluoroethylene resin or glass wool-containing tetrafluoroethylene resin, which is placed on both sides of the valve plate, and seals around the fluid passage (15AX15B) and the valve plate. In the raised position of υ, the movement range of the valve plate covers the valve hole (21b) of the valve plate p in the vertical direction l, respectively.

It is formed into a rectangular shape with a long side that is 72 minutes long.

In addition, among these seal plates (E) (Foundation), the valve plate @ front seal plate (To) has a concave portion (26a) on the back surface of the valve plate (E), which is connected to a protrusion provided inside the valve box αe of the first frame ση. (17a) and is fixed to the first frame αη, and the seal plate slope on the rear face of the valve plate &1) is fitted into the concave part (27a) on the back face and the protrusion (19a) protruding from the second frame α. ) and is fixed to the second frame α wound,
Furthermore, the surface of each seal plate kanji is connected to the first frame qη
The second frame α value is pressed against the valve plate by the bolt to which it is attached. (28a) represents the first frame αη and the second frame body αη.
This is a seal backing interposed between the frame Q and the frame Q.

The handle is a high-pressure liquid pump that pumps the cleaning liquid in the liquid storage tank (7) through a supply pipe (to) connected to a supply hole provided in the lid body (1) with a solenoid valve 311 interposed therein. Supplied in box αe. The discharge pressure of this high-pressure liquid bonder is set to be much higher than the liquid pressure of the liquid souffle, and when the gate valve αM is operated, the cleaning liquid is injected into the valve hole (21b) through the small hole. In addition, the volume of the cleaning liquid inside the valve box α is adjusted by increasing and decreasing the volume of the valve body α0 during opening and closing operations, that is, the volume of the valve body (c) that is taken in and taken out from the valve box al. conduct. The cleaning liquid port uses a liquid souffle, that is, a liquid obtained by turning powder into a slurry, and generally water.

Next, a method of cleaning this gate valve αυ will be explained.

When the gate valve αυ is closed and opened, the valve plate (c) is in the position shown in Figure 1 (
The electromagnetic valve C31) is stopped at the raised position and the lowered position shown by the solid line and the imaginary line of al, the solenoid valve C31) is closed, the pump head is also stopped, and the gate valve 01) is not cleaned. At this time, the cleaning liquid pressure inside the valve box αQ is kept constant, and the small hole (a)
Also, since the valve hole (21b) is open at the top, solid particles will not enter into the valve box αe through the small hole. Next, when opening and closing the gate valve αυ, that is, the valve plate? When υ is raised or lowered, the bonder is operated, the solenoid valve Gll is opened, and the cleaning liquid @ is supplied into the valve box α0, and the cleaning liquid inside the valve cylinder αQ is passed through the small hole 4 and into the valve hole (21b). The fluid slurry in the valve hole (21b) is fed to the fluid passageway (15A).
X15B) to dilute the fluid slurry 1 and provide a flow to the diluted slurry in the valve hole (21b) so that the solid particles reach the valve plate cl! Prevents it from being caught between υ and the seal plate (E). Note that the closing operation is performed using the valve hole (21b
), the operating time is lengthened, that is, the rising speed of the valve plate CD is slowed down, and the operating time is shortened by increasing the descending speed of the valve plate αG during the opening operation, contrary to the closing operation. This prevents the concentration of the liquid slurry from decreasing.

The above describes a method for cleaning a gate valve installed in a pipe that transports a liquid slurry containing solid particles, but it may also be a method for cleaning a gate valve installed in a pipe that transports powder particles by air. .

In this case, cleaning air is supplied, but since air is compressible, if the air is not forced into the valve hole and into the valve box when the gate valve is opened and closed, fine particles will enter the valve box. Therefore, it is necessary to constantly pressurize air with a high-pressure air pump to maintain the air pressure inside the valve box.

Effects of the Invention As described above, according to the present invention, the cleaning fluid is pumped into the valve hole of the valve plate, so the fluid in the valve hole is diluted, the degree of freedom of solid particles in the fluid is increased, and the solid particles are Even if particles hit a part of the corner of the valve hole, they will easily escape, and the flow caused by the injection of cleaning fluid will also promote the movement of solid particles, reducing the chance of solid particles getting caught between the valve plate and the seal plate. And wear and loss of the seal plate can be significantly reduced.

[Brief explanation of drawings]

Fig. 1 (at (bl) is a side sectional view showing one embodiment of the present invention, Fig. 2 is a sectional view taken along the line II in Fig. 1, Fig. 3 is a front view of the seal plate, and Figs. 4 to 6 The figures show a conventional example, Fig. 4 is a side sectional view showing the conventional example, and Fig. 5 (at (b)
6(a)(bl) is a side sectional view showing another conventional example.
is an explanatory diagram thereof. αD...Gate valve, (2)...Body, (15A)...
- Inlet side fluid passage, (15B)... Outlet side fluid passage,
αO...valve box, ση...first frame, σ groan...second
Frame body, (E)... Lid body, 3η... Valve body, (21a)
...Occluded part, (21b)...Valve hole, @...Small hole, (C)...Cleaning liquid, (E)...Seal plate, gradient...
...Seal plate, wire...High pressure liquid pump representative Yoshihiro Morimoto Figure 4 @ Figure 5
(ν) 1st,mu (ν)

Claims (1)

[Claims] 1. Cleaning the gate valve with a full seal on the valve plate, which always isolates the valve hole provided in the valve plate from the inside of the valve box by the seal plate that is pressed against both sides of the valve plate when opening and closing the gate valve and during opening/closing operations. A method for cleaning a gate valve with a full seal on a valve plate, characterized in that cleaning fluid is pressurized from inside the valve box into the valve hole through a small hole provided in the valve plate that communicates the inside of the valve box with the valve hole. .