JP2004124997A - Knife gate valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a knife gate valve preventing the consolidation of a solid matter in fluid such as slurry intruding into a slit and an annular space, properly keeping the adhesion of a knife plate and a seat ring, and improving the closing performance. <P>SOLUTION: A liquid reservoir part 12 communicated with the slit 4 is formed on a bottom part of a casing 1, a cleaning fluid supply pipe 13 is connected to one end side of the liquid reservoir part 12, a cleaning fluid discharge pipe 14 is connected to the other end side of the liquid reservoir part 12, further the cleaning fluid supply pipe is connected to an upper part of the annular space 11 formed between a thin part 5c of the seat ring 5 and the casing 1, and the cleaning fluid discharge pipe 16 is connected to a bottom part of the annular space 11. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a knife gate valve.
[0002]
[Prior art]
Generally, a knife gate valve is provided in the middle of a pipe through which a fluid such as a slurry flows in a desulfurization apparatus or other various devices, and opens and closes a flow path thereof.
[0003]
FIGS. 4 to 6 show an example of a conventional knife gate valve. The knife gate valve is provided in a casing 1 provided in a pipe (not shown) through which a fluid such as slurry flows. A knife plate 3 for cutting off the knife plate 3 is provided so as to be insertable and removable along the slit 4, and the knife plate 3 is not inserted into a peripheral portion of the slit 4 where the knife plate 3 is inserted and removed on the inner surface side of the flow path 2. At the time of insertion of the knife plate 3, a seat ring 5 is provided which is in close contact with each other and which is in close contact with both surfaces of the knife plate 3 to make it liquid-tight.
[0004]
As shown in FIG. 4, a yoke 6 is erected on the casing 1, and a hydraulic cylinder 7 is mounted vertically downward on the yoke 6, and a tip of a rod 8 of the hydraulic cylinder 7 is connected to an upper end of the knife plate 3. In addition, as shown in FIGS. 5 and 6, an inner lining 9 is lined on the inner surface of the casing 1 on the side of the flow path 2 and the inner surface of the slit 4.
[0005]
On the other hand, the seat ring 5 is a cylindrical member formed of an elastic body such as rubber, and is composed of a liquid-tight holding portion 5a arranged on the knife plate 3 side and a flange arranged on the side opposite to the knife plate 3. And a thin portion 5c connecting the flange portion 5b and the liquid-tight holding portion 5a. A reinforcing ring 5d is embedded in the liquid-tight holding portion 5a, and a retainer flange 5e is embedded in the flange portion 5b. The flange portion 5b in which the retainer flange 5e is embedded is fixed to the casing 1 by tightening bolts 10.
[0006]
In the knife gate valve as described above, when the rod 8 of the hydraulic cylinder 7 is extended from the state shown in FIGS. 4 to 6, the knife plate 3 causes the liquid-tight holding portion 5a of the seat ring 5 in close contact with each other. Is pushed down to open, the flow path 2 is shut off, and the liquid-tight holding portion 5a of the seat ring 5 comes into close contact with both surfaces of the knife plate 3, thereby preventing leakage of fluid such as slurry. When the rod 8 of the hydraulic cylinder 7 is contracted from the state in which the flow path 2 is shut off, the knife plate 3 is raised, the flow path 2 is opened, and the liquid-tight holding portion 5a of the seat ring 5 is opened. Again, they are kept in close contact with each other.
[0007]
It is to be noted that a knife gate valve in which a valve element is moved to open and close by turning a handle is also generally known (for example, see Patent Document 1).
[0008]
[Patent Document 1]
JP-A-59-144876 (pages 1-2, FIG. 1)
[0009]
[Problems to be solved by the invention]
However, as described above, when the knife plate 3 is opened and closed, the liquid-tight holding portions 5a of the seat rings 5 that are in close contact with each other are pushed and opened by the knife plate 3, so that fluid such as slurry flows. If it enters the slit 4 and the annular space 11 formed between the thin portion 5c of the seat ring 5 and the casing 1 and flows down to the bottom of the casing 1 by its own weight and accumulates, it has been used for a long time. The solid content in the fluid such as the slurry which has entered the slit 4 and the annular space 11 is compacted, and the adhesiveness between the knife plate 3 and the liquid-tight holding portion 5a of the seat ring 5 is hindered, resulting in poor tightening. Had the drawback. Furthermore, the solid content in the fluid such as slurry is condensed also in the slit 4 at the valve bottom, and in the worst case, the knife plate 3 does not completely enter the slit 4 at the valve bottom, so that there is a drawback that the cut-off cannot be performed. Was.
[0010]
In view of such circumstances, the present invention can prevent solids in a fluid such as slurry that has entered the slit and the annular space from being compacted, and can maintain good adhesion between the knife plate and the seat ring. Another object of the present invention is to provide a knife gate valve that can improve the shutoff performance.
[0011]
[Means for Solving the Problems]
According to the present invention, a knife plate for blocking a flow path is provided so as to be insertable / removable along a slit with respect to a casing provided in the middle of a pipe through which a fluid flows, and a flow path of the slit through which the knife plate is inserted / removed. A knife gate valve in which a peripheral portion on the inner surface side is provided with a seat ring which is in close contact with each other when the knife plate is not inserted and which is in close contact with both surfaces when the knife plate is inserted to be liquid-tight,
A liquid reservoir communicating with the slit is formed at the bottom of the casing, and a cleaning fluid supply pipe is connected to one end of the liquid reservoir and a cleaning fluid discharge pipe is connected to the other end of the liquid reservoir. The present invention relates to a knife gate valve characterized by the following.
[0012]
According to the above means, the following effects can be obtained.
[0013]
When the knife plate is opened and closed, the sheet rings that are in close contact with each other are pushed and opened by the knife plate, so that fluid such as slurry enters the slit and is formed on the bottom of the casing by its own weight. When the cleaning fluid is supplied from a supply pipe connected to one end of the liquid reservoir, the fluid such as the slurry which has flowed down to the liquid reservoir is discharged together with the cleaning fluid into the liquid reservoir. It is discharged from the discharge pipe connected to the end side.
[0014]
As a result, even when used for a long time, the solid content in the fluid such as the slurry that has entered the slit can be prevented from being consolidated, the adhesion between the knife plate and the seat ring is not hindered, and the tightness is poor. No worries. In addition, the solid content in the fluid such as the slurry that has entered the slit in the valve bottom is prevented from being compacted in the valve bottom, and the knife plate easily enters the slit in the valve bottom.
[0015]
In the knife gate valve, the bottom surface of the liquid reservoir can have a downward slope from one end to the other end, so that the fluid such as the slurry flowing down to the liquid reservoir can be washed. The fluid can be more reliably discharged from the discharge pipe.
[0016]
Furthermore, in the knife gate valve, a cleaning fluid supply pipe is connected to an upper portion of an annular space formed between a seat ring and a casing, and a cleaning fluid discharge pipe is connected to a bottom of the annular space. In this case, not only the fluid such as the slurry that has entered the slit when opening and closing the knife plate, but also the fluid such as the slurry that has entered the annular space and flowed down to the bottom, the upper part of the annular space By supplying the cleaning fluid from the supply pipe connected to the nozzle, it is possible to discharge the cleaning fluid together with the cleaning fluid from the discharge pipe connected to the bottom of the annular space, and to ensure the close contact between the knife plate and the seat ring. More effective.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0018]
1 to 3 show an example of an embodiment of the present invention. In the drawings, portions denoted by the same reference numerals as those in FIGS. 4 to 6 represent the same components, and the basic configuration is shown in FIGS. 6 is the same as the conventional one shown in FIG. 6, but the feature of this example is that, as shown in FIGS. 1 to 3, a liquid reservoir 12 communicating with the slit 4 is formed at the bottom of the casing 1. A supply pipe 13 for a cleaning fluid (eg, water, cleaning slurry, air, etc.) is connected to one end of the liquid reservoir 12, and a discharge pipe 14 for the cleaning fluid is connected to the other end of the liquid reservoir 12. It is in the point which did.
[0019]
In the case of the illustrated example, the bottom surface of the liquid reservoir 12 is provided with a slope (see FIG. 1) having a downward slope from one end to the other end, and further has a thin portion 5c of the seat ring 5. A cleaning fluid supply pipe 15 is connected to an upper portion of an annular space 11 formed between the casing 1 and a cleaning fluid discharge pipe 16 is connected to a bottom of the annular space 11.
[0020]
1 to 3, reference numeral 17 denotes an on-off valve provided in the supply pipe 13, 18 denotes an on-off valve provided in the discharge pipe 14, 19 denotes an on-off valve provided in the supply pipe 15, and 20 denotes This is an opening / closing valve provided in the middle of the discharge pipe 16, and when supplying the cleaning fluid, the opening / closing valves 17, 18 and the opening / closing valves 19, 20 are opened.
[0021]
Next, the operation of the illustrated example will be described.
[0022]
When the knife plate 3 is opened and closed, the liquid tight holding portion 5a of the seat ring 5 that is in close contact with each other is pushed and opened by the knife plate 3, so that a fluid such as slurry enters the slit 4, and By its own weight, it flows down to the liquid reservoir 12 formed at the bottom of the casing 1. When the cleaning fluid is supplied from the supply pipe 13 connected to one end of the liquid reservoir 12, the slurry flowing down to the liquid reservoir 12 The fluid such as is discharged from the discharge pipe 14 connected to the other end of the liquid reservoir 12 together with the cleaning fluid.
[0023]
Here, since the bottom surface of the liquid reservoir 12 is inclined downward from one end to the other end, the fluid such as the slurry flowing down to the liquid reservoir 12 is further washed by the cleaning fluid. It is possible to reliably discharge from the discharge pipe 14.
[0024]
As a result, even when used for a long period of time, the solid content in the fluid such as the slurry that has entered the slit 4 is prevented from being consolidated, and the knife plate 3 and the liquid-tight holding portion 5a of the seat ring 5 are in close contact with each other. There is no fear that the tightness will not be impaired and the tightening will be worse. In addition, the solid matter in the fluid such as the slurry that has entered the slit 4 in the valve bottom is prevented from being consolidated into the valve bottom, and the knife plate 3 easily enters the slit 4 in the valve bottom, so that the deadline is poor. There is no.
[0025]
Further, in the illustrated example, a cleaning fluid supply pipe 15 is connected to an upper portion of an annular space 11 formed between the thin portion 5c of the seat ring 5 and the casing 1, and a cleaning fluid is connected to the bottom of the annular space 11. Since the fluid discharge pipe 16 is connected, not only the fluid such as the slurry entering the slit 4 when opening and closing the knife plate 3 but also the fluid such as the slurry entering the annular space 11 and flowing down to the bottom. By supplying the cleaning fluid from the supply pipe 15 connected to the upper part of the annular space 11, the cleaning fluid can be discharged from the discharge pipe 16 connected to the bottom of the annular space 11 together with the cleaning fluid. This is more effective in securing the adhesion between the seat ring 5 and the liquid-tight holding portion 5a.
[0026]
In this way, it is possible to prevent the solids in the fluid such as the slurry that has entered the slit 4 and the annular space 11 from being compacted, and to improve the adhesion between the knife plate 3 and the liquid-tight holding portion 5 a of the seat ring 5. , And the cutoff performance can be improved.
[0027]
It should be noted that the knife gate valve of the present invention is not limited to the illustrated example described above, and it is needless to say that various changes can be made without departing from the gist of the present invention.
[0028]
【The invention's effect】
As described above, according to the knife gate valve of the present invention, it is possible to prevent the solid content in the fluid such as the slurry, which has entered the slit and the annular space, from being consolidated, and the knife plate and the seat ring are connected to each other. An excellent effect that good adhesion can be maintained and shutoff performance can be achieved can be achieved.
[Brief description of the drawings]
FIG. 1 is a front view of an example of an embodiment of the present invention.
FIG. 2 is a sectional view corresponding to a section taken along line II-II of FIG.
FIG. 3 is a cross-sectional view corresponding to the line III-III in FIG. 1;
FIG. 4 is a front view of an example of a conventional knife gate valve.
FIG. 5 is a view corresponding to a section taken along line VV of FIG. 4;
FIG. 6 is a view corresponding to a section taken along the line VI-VI of FIG. 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Casing 2 Flow path 3 Knife plate 4 Slit 5 Seat ring 5a Liquid tight holding part 5b Flange part 5c Thin part 11 Annular space 12 Liquid reservoir 13 Supply pipe 14 Discharge pipe 15 Supply pipe 16 Discharge pipe

Claims (3)

In the knife gate valve,
A liquid reservoir communicating with the slit is formed at the bottom of the casing, and a cleaning fluid supply pipe is connected to one end of the liquid reservoir and a cleaning fluid discharge pipe is connected to the other end of the liquid reservoir. Knife gate valve characterized by the following. 2. The knife gate valve according to claim 1, wherein the bottom surface of the liquid reservoir is inclined so as to have a downward slope from one end to the other end. 3. The knife gate valve according to claim 1, wherein a cleaning fluid supply pipe is connected to an upper part of an annular space formed between the seat ring and the casing, and a cleaning fluid discharge pipe is connected to a bottom part of the annular space. .

Images