JPH09210342A - Powder hermetically sealed valve actuation protector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a foreign matter and a powder from biting a sealing surface of an opening/closing valve, and prevent a valve body from flowing into a cavity part, and hereby avoid operation failure of the valve and protect a sealing property in a hermetically sealed valve of a rock hopper apparatus applicable to a powder system such as a dried coal supply apparatus such as a pressurized fluidized bed boiler and a pressurized coal gasifying furnace. SOLUTION: Purging compressed gas interlocks a solenoid valve 38 one simultaneously receiving an opening/closing instruction signal for a ball 32 disposed in a valve body 31 used for a rock hopper apparatus, and purges a cavity part 35 in the valve body and the ball 32 with compressed gas during the actuation of the ball for several seconds until the rotation of the ball 32 is interrupted as indicated in the figure (b) to prevent a powder from entering the cavity part and blow off a powder and a foreign matter adhered to the surface of the sealing surface 34 and the ball 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airtight valve of a lock hopper device applied to a powder system such as a pressurized fluidized bed boiler and a dry coal feeder in a pressurized coal gasification furnace.

[0002]

2. Description of the Related Art A conventional airtight valve will be described by taking a ball valve as an example. 2 is a structural diagram of a ball valve as a conventional airtight valve, FIG. 3 is a system diagram showing an example of a conventional lock hopper device, and FIG. 4 is an explanatory diagram showing the operation of the lock hopper device of FIG.

In FIG. 2, 31 is an opening / closing valve body, 32 is a ball of the valve body 31, 33 is a seat disposed inside the valve body 31, and a sealing surface 34 is a ball 32 and a seat 3.
3 formed to keep the valve airtight.

Reference numeral 35 denotes a cavity inside the valve body 31.

2A shows the closed state of the valve,
(B) is a diagram showing a state where the ball 32 has started to rotate clockwise and has an intermediate opening degree, and (c) is a diagram showing a fully opened state of the valve.

Next, a conventional lock hopper device will be described with reference to FIG. In the figure, reference numerals 1, 2 and 3 denote a hopper 1, a hopper 2 and a hopper 3, respectively. At the outlet of each hopper, raw material discharge chutes 4, 5, 6 are provided.
The chute 4 and 5 have valves 7, 8 and 9, 1 respectively.
0 is set. The hopper 1 is maintained at substantially atmospheric pressure, but the hopper 3 is pressurized.

The lock hopper device has a hopper 3 which pressurizes powder in the hopper 1 which is maintained at about atmospheric pressure.
4 and the operating principle thereof is shown in FIG.

In step 1 of FIG. 4 (a), the powder is in the hopper 1 kept at about atmospheric pressure, and the valves 7 and 8 are used.
And 9 and 10 are closed. In FIG. 4, the valve on the white background is in the open state, and the valve in black is in the closed state.

First, the valve 8 is opened in step 2 of FIG. 2B, and the valve 7 is further opened in step 3 of FIG. 3C so that the powder falls into the hopper 2 which is maintained at about atmospheric pressure.

(D) In Step 4 of the figure, the valves 7 and 8 are closed, and then the hopper 2 is pressurized to the same pressure as that of the hopper 3 by the pressurizing means (not shown).

Then, the valve 10 is opened in step 5 of FIG. 6 (e), and the valve 9 is further opened in step 6 of FIG. 6 (f) so that the powder falls into the hopper 3 to achieve a predetermined purpose.

Finally, in step 7 of FIG. 7 (g), the valves 9 and 1 are
0 is closed, and then the hopper 2 is depressurized (not shown).
This reduces the pressure to about atmospheric pressure.

Next, the raw material is received in the hopper 1, the state returns to the state of step 1, and the above procedure is repeated again.

Since the valves 7 and 9 are opened in the powder atmosphere in steps 3 and 6, respectively, the valves wear quickly, but this problem cannot be solved in principle. Therefore, the valves 7 and 9 are generally used for the purpose of blocking the powder, and it is customary that the high pressure sealing is performed by the valves 8 and 10.

[0015]

In the conventional lock hopper device as described above, when the valve 8 and the valve 10 are opened and closed, the surrounding atmosphere is a gas, but dust in the gas and the valve seat surface are present. There was a problem that foreign matter and powder adhering in the vicinity were caught in the valve seal surface, causing malfunction and accelerating wear.

That is, in the case of the conventional ball valve as the airtight valve shown in FIG. 2, from the closed state shown in FIG. 2A to FIG.
At the time of transition to the open state shown in FIG. 2, the balls 32 rotate, so that the powder 20 enters the cavity portion 35 of the valve body at the intermediate opening position shown in FIG. And bite between the sealing surface 34,
It causes a malfunction that causes a malfunction stick and wears the valve seat surface.

An object of the present invention is to provide a new powder type airtight valve actuation protection device which prevents these problems.

[0018]

As a structure for achieving the above-mentioned object, the powder type airtight valve operation protection device of the present invention has two components.
In a powder supply lock hopper device having two or more bases for storing powder and two or more on-off valves for chutes connecting the hoppers, foreign matter or powder on the sealing surface of the on-off valve And a purge gas supply device for introducing a purge gas into the inside of the on-off valve in order to prevent the gas from being caught and flow into the cavity portion are connected through a through hole provided in the side wall of the valve body. .

Further, a plurality of purging pipes are connected to the side surface of the valve body from the purging gas supply device via a solenoid valve so that the solenoid valve is operated in conjunction with the opening / closing command signal of the valve body inlet / outlet opening / closing valve. It is preferable to configure.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION An example of the best mode for carrying out the present invention will be described below with reference to FIG. 1 (a) is a closed state diagram of the powder-type airtight valve of the present invention, (b) is an intermediate opening state diagram,
(C) shows an open state diagram.

In the figure, reference numeral 31 denotes a valve body used in a lock hopper device, in which an upper end is an inlet and a lower end is an outlet, and a ball 32 is arranged inside. The ball 32 has a drive shaft 3
Rotate around 9. Reference numeral 33 denotes a seat that is disposed inside the valve body and is in circumferential contact with the outer circumference of the ball 32, and 34 denotes a sealing surface formed by the contact surface between the outer circumference of the ball 32 and the seat 33.

Reference numeral 35 is a cavity portion formed inside the valve body 31, 36 and 37 are purging pipes, and 38 is a solenoid valve.

In the powder-type airtight valve shown in FIG. 1 which opens and closes the inlet / outlet of the valve body 31, the purging pipe 36 includes the solenoid valve 3
8 is connected to one side surface of the valve body 31 via the drive shaft 3
It is perpendicular to 9.

The other purge pipe 37 is connected to the side surface of the valve body 31 at a position symmetrical to the pipe 36, and the pipe 37
Is branched from a pipe 36 connecting the solenoid valve 38 and the valve body.

The connection position of each purge pipe is the valve body 31.
It is connected near the exit side seat 33.

The purge pipe is connected to the inside of the valve main body from both sides of the valve main body 31 via a solenoid valve to a supply device of the purge gas made of compressed gas, but the entire ball 32 and the entire cavity portion 35 are purged. Therefore, the valve body 31
Before being connected to, the pipe is further branched into a plurality of purge pipes.

Next, the operation of the apparatus of this embodiment will be described. The purging gas, which is a compressed gas, is the ball 32.
When the ball 32 is in operation for several seconds until the ball operation is stopped by operating the solenoid valve 38 at the same time as the opening / closing command signal, the cavity portion and the ball 32 are purged by the compressed gas, and the powder to the cavity portion is discharged. By preventing entry, and by blowing away the powder and foreign substances adhering to the seal surface and the surface of the ball 32, the powder is not caught between the ball 32 and the seat surface 34, and malfunctions and sticks are avoided. I can do things. The timing of charging the compressed gas is from when the ball valve is commanded to be opened to closed and when it is closed to opened until the operation is stopped.

The operation sequence of the airtight valve by the lock hopper device is omitted since it is the same as the conventional one described in FIG.

[0029]

According to the powder-type airtight valve operation protection device of the present invention, it can be widely applied to a valve (burner valve, shutoff valve) through which powder always passes, and malfunction of the valve due to trapping of powder or You can avoid the stick.

Further, since powders and foreign matters near the seat surface can be removed, there is an effect that the wear of the ball surface and the airtightness of the valve can be maintained.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the structure of a powder type airtight valve of the present invention,
(A) is a valve closed state diagram, (b) is an intermediate opening state diagram,
(C) is an open state diagram.

FIG. 2 is a vertical cross-sectional view of a conventional powder-type airtight valve, in which (a) is a valve closed state diagram, (b) is an intermediate opening state diagram, and (c) is an open state diagram.

FIG. 3 is a system diagram showing a lock hopper device.

FIG. 4 is an explanatory diagram showing an operation of the lock hopper device.

[Explanation of symbols]

 1,2,3 Hopper 4,5,6 Raw material discharge chute 7,8,9,10 Valve 20 Powder 31 Valve body 32 Ball 33 Seat 34 Sealing surface 35 Cavity 36,37 Purge pipe 38 Solenoid valve

Claims (2)

[Claims] 1. A lock hopper device for powder supply, comprising two or more powder storage hoppers and two or more on-off valves each on a chute connecting the hoppers, wherein a sealing surface of the on-off valves. A purge gas supply device that introduces a purge gas into the inside of the on-off valve to prevent foreign matter and powder from getting into the cavity and from flowing into the cavity is connected through a through hole provided in the side wall of the valve body. A powder-type airtight valve actuation protection device characterized in that 2. A plurality of purging pipes are connected to a side surface of the valve body from a purging gas supply device via a solenoid valve, and the solenoid valve is operated in conjunction with an opening / closing command signal of the opening / closing valve. The powder-type airtight valve operation protection device according to claim 1.