A buffer pressure relief device for descaling pump

Abstract

The present invention belongs to the technical field of high-pressure water descaling systems in the metallurgical industry, and discloses a buffering pressure relief device for a descaling pump to solve the problems of a short service life of a back pressure relief circuit of a primary descaling system, water leakage causing interruption of production, etc. The buffering pressure relief device comprises a pressure relief valve, a three-way pipe joint is connected to the pressure relief valve, one end of the three-way pipe joint is connected to a low-pressure return water pipeline, and the other end of the three-way pipe joint is connected to a buffering pressure relief circuit, the buffering pressure relief circuit comprises a first outer sleeve, one end of the first outer sleeve is connected to the three-way pipe joint, and the other end of the first outer sleeve is connected to a second outer sleeve, a buffer valve core is installed in the inner cavity at the connection between the first outer sleeve and the second outer sleeve, a cut-off hole is provided in the radial direction of the buffer valve core, a valve core flow channel is provided in the axial direction of the buffer valve core, and the inner cavity of the first outer sleeve, the valve core flow channel and the inner cavity of the second outer sleeve are all connected, and a bypass pipeline is connected to the end of the second outer sleeve, and the bypass pipeline is connected to the low-pressure return water pipeline.

Description

Technical Field

[0001] The invention relates to the technical field of high-pressure water descaling systems in the metallurgical industry, and in particular to a buffer pressure relief device for a descaling pump. Background Art

[0002] CSP continuous casting and rolling production line is a relatively advanced production line in the field of modern hot-rolled strip production. It has the characteristics of one-time forming and compact connection. Among them, hot rolling is an important process in the whole production line. It integrates heating, descaling, rolling, layer cooling, coiling and other process steps into one production unit. The high-pressure water descaling system is the top priority to ensure product quality in this production unit. Its function is to use 9 high-pressure pumps to pressurize DC2 cooling water, and then use the descaling machine header nozzle to spray it onto the surface of the hot-rolled strip coming out of the heating furnace, remove all the iron oxide scale on its surface, and then enter the continuous rolling unit for rolling. In the production process, once the one-time descaling system fails, it will directly lead to insufficient descaling pressure, and the iron oxide scale on the surface of the hot-rolled strip cannot be completely removed, which will eventually lead to the quality defect of slag inclusion in the rolled hot-rolled strip, seriously affecting the quality and brand image of the hot-rolled strip products. Sometimes, in order to achieve the purpose of stopping losses, production can only be interrupted.

[0003] The inlet manifold of the high-pressure water descaling system is pressure-regulated by a combination of 3 quantitative pumps and 1 variable frequency pump, and the outlet manifold is pressure-regulated by a combination of 4 quantitative pumps and 1 variable frequency pump. When the system is waiting for steel normally, the pressure is adjusted by each pump outlet. Figure 1 The high-pressure water relief valve A of the back-pressure relief circuit F1 releases pressure to put the system in a low-pressure pre-flushing state. At this time, the inlet header pressure is 23 bar and the outlet header pressure is 31 bar. When the hot-rolled strip passes through the descaling machine, the high-pressure water relief valve A of the back-pressure relief circuit F1 is closed and descaling begins. When descaling is completed, the high-pressure water relief valve A of the back-pressure relief circuit F1 on each pump releases pressure instantly to restore the system to a low-pressure pre-flushing state.

[0004] Since the pressure of high-pressure water descaling is very high, the inlet header is 240bar, and the outlet header is 380bar, the frequency of descaling is also very high, about 500 times per working day, that is, the descaling pump needs to release pressure about 500 times per day, which brings extremely frequent and great impact to the pressure relief circuit pipeline after the high-pressure water pressure relief valve A of the back pressure relief circuit F1. A major problem caused by this working condition is the leakage of the back pressure relief circuit F1 pipeline, which is mainly reflected in the joint D at the outlet of the high-pressure water pressure relief valve A of each pump back pressure relief circuit F1, the three-way pipe joint E part, the back pressure relief circuit F1 pipeline itself and the plug H. The back pressure relief circuit F1 is generally maintained and replaced with new spare parts for a service life of about 25 days, and sometimes there may be serious leakage in less than 25 days. During the production process, water leakage occurs in the back pressure relief circuit F1 of a pump in the primary descaling system, which will directly lead to unstable descaling pressure and incomplete cleaning of the oxide scale on the surface of the hot-rolled strip, resulting in slag inclusion quality defects. Especially when producing steel grades with a tight production rhythm, production can only be interrupted decisively to prevent the production of large quantities of unqualified products, which seriously affects production efficiency. The existing technology cannot solve the above technical problems. Summary of the invention

[0005] The purpose of the present invention is to solve the problems of short service life of the back pressure relief circuit of the prior art primary descaling system and interruption of production caused by water leakage, and to provide a buffer pressure relief device for a descaling pump.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A buffer pressure relief device for a descaling pump comprises a pressure relief valve, a three-way pipe joint is connected to the pressure relief valve, one end of the three-way pipe joint is connected to a low-pressure return water pipeline, and the other end of the three-way pipe joint is connected to a buffer pressure relief circuit, the buffer pressure relief circuit comprises a first outer sleeve, one end of the first outer sleeve is connected to the three-way pipe joint, and the other end of the first outer sleeve is connected to a second outer sleeve, a buffer valve core is installed in the inner cavity at the connection between the first outer sleeve and the second outer sleeve, a cut-off hole is provided in the radial direction of the buffer valve core, a valve core flow channel is provided in the axial direction of the buffer valve core, and the inner cavity of the first outer sleeve, the valve core flow channel and the inner cavity of the second outer sleeve are all connected, and a bypass pipeline is connected to the end of the second outer sleeve, and the bypass pipeline is connected to the low-pressure return water pipeline.

[0008] Furthermore, a large end of the valve core is provided at one end of the buffer valve core, and the large end of the valve core cooperates with a large end mounting cavity arranged on the inner side of the first outer sleeve; a sleeve is provided at one end of the buffer valve core, and the sleeve is installed in cooperation with a small end mounting cavity arranged on the inner side of the second outer sleeve, and a return spring is provided between the large end of the valve core and the end face of the second outer sleeve.

[0009] Furthermore, one end of the second outer sleeve away from the bushing is threadedly connected with a screw plug, and a screw plug channel is provided on the screw plug.

[0010] Furthermore, the screw plug is provided with a screw plug interface, and the screw plug interface is connected to the bypass pipeline.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] The present invention is mainly designed for the return water pipeline of the descaling pump in the hot rolling high-pressure water descaling system. The present invention can extend the maintenance period of the descaling pump pressure relief circuit and improve the reliability of the pressure relief circuit. The back pressure relief circuit of the original pressure relief circuit is designed and transformed into a buffer pressure relief circuit, extending the original 25-day maintenance period to 8-10 months, reducing the frequency of equipment maintenance, and keeping the descaling system pressure in a normal and stable state, thereby ensuring the efficient production rhythm and high-quality product quality of hot-rolled strip steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the present invention.

[0014] Figure 2 This is a schematic diagram of the assembly structure of the buffer pressure relief circuit of the present invention.

[0015] Figure 3 It is a schematic structural diagram of the first outer jacket of the present invention.

[0016] Figure 4 It is a schematic structural diagram of the second outer jacket of the present invention.

[0017] Figure 5 It is a structural schematic diagram of the buffer valve core of the present invention.

[0018] Figure 6 It is a schematic structural diagram of the bushing of the present invention.

[0019] Figure 7 It is a schematic structural diagram of the wire plug of the present invention.

[0020] The meanings of the reference numerals are as follows: 1. first outer sleeve; 2. second outer sleeve; 3. buffer valve core; 4. bushing; 5. screw plug; 6. return spring; 7. shut-off hole; 8. valve core flow channel; 9. screw plug channel; 10. screw plug interface; 11. large end installation cavity; 12. small end installation cavity; 13. valve core large end. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0022] like Figure 1-7As shown, a buffer pressure relief device for a descaling pump includes a pressure relief valve A, a three-way pipe joint E is connected to the pressure relief valve A through a joint D, one end of the three-way pipe joint E is connected to a low-pressure return water pipeline B, and the other end of the three-way pipe joint E is connected to a buffer pressure relief circuit F, the buffer pressure relief circuit F includes a first outer sleeve 1, one end of the first outer sleeve 1 is connected to the three-way pipe joint E through a thread, and the other end of the first outer sleeve 1 is connected to a second outer sleeve 2 through a thread, and a buffer valve core 3 is installed in the inner cavity at the connection between the first outer sleeve 1 and the second outer sleeve 2. A shutoff hole 7 is provided in the radial direction of the punch valve core 3, a valve core flow channel 8 is provided in the axial direction of the buffer valve core 3, and the inner cavity of the first outer sleeve 1, the valve core flow channel 8 and the inner cavity of the second outer sleeve C are all connected, and a valve core big end 13 is provided at one end of the buffer valve core 3, and the valve core big end 13 cooperates with the big end mounting cavity 11 arranged on the inner side of the first outer sleeve 1, and a bushing 4 is installed at one end of the buffer valve core 3, and the bushing 4 is installed in cooperation with the small end mounting cavity 12 arranged on the inner side of the second outer sleeve 2, and a return spring 6 is installed between the valve core big end 13 and the end face of the second outer sleeve 2.

[0023] The end of the second outer sleeve 2 away from the bushing 4 is threadedly connected with a screw plug 5, and a screw plug channel 9 is opened on the screw plug 5. The end of the screw plug 5 is also provided with a screw plug interface 10, which is connected to the bypass pipeline C, and the bypass pipeline C is connected to the low-pressure return water pipeline B.

[0024] In production applications, when high-pressure water is instantly released from the high-pressure water relief valve A, it passes through the joint D and the three-way joint E according to the flow direction of the water, enters the first outer sleeve 1 at the first time, and reaches the position of the buffer valve core 3. Under the thrust of the released water, the buffer valve core 3 begins to move along the direction of the water flow under the guidance of the bushing 4.

[0025] The buffer valve core 3 is provided with a intercepting hole 7 of φ4 in the radial direction. Under the action of the intercepting hole 7 of φ4, the water outside the buffer valve core 3 will flow into the inside of the buffer valve core 3.

[0026] At the same time, the buffer valve core 3 also moves in the direction of the water flow until it approaches the limit position of the return spring 6, at which time the first step of the instantaneous pressure relief process is completed.

[0027] Subsequently, most of the leakage water released from the high-pressure water relief valve A rebounds from the top of the buffer valve core 3, returns to the other side outlet of the three-way joint E and flows back to the low-pressure return water pipeline B.

[0028] Another part of the water flows back to the low-pressure return pipe B through the φ8 valve core flow channel 8 in the middle of the buffer valve core 3, the second outer sleeve 2 cavity, the φ6 wire plug channel 9 and the DN6 bypass pipe C. At this time, the second step of the pressure relief process is completed.

[0029] Then, the buffer valve core 3 is gradually reset under the action of the reset spring 6 until it is completely reset at the beginning of the next descaling, at which time the entire buffer pressure relief process is completed.

[0030] It should be noted that the bypass pipe C installed between the bottom of the buffer pressure relief loop F and the low-pressure return pipe B has a low inlet and a high outlet, that is, the inside of the buffer pressure relief loop F is always filled with water.

Claims

1. A buffer pressure relief device for a descaling pump, comprising a pressure relief valve (A), a three-way pipe joint (E) connected to the pressure relief valve (A), one end of the three-way pipe joint (E) connected to a low-pressure return water pipeline (B), and the other end of the three-way pipe joint (E) connected to a buffer pressure relief circuit (F), wherein: The buffer pressure relief circuit (F) comprises a first outer sleeve (1), one end of the first outer sleeve (1) is connected to a three-way pipe joint (E), the other end of the first outer sleeve (1) is connected to a second outer sleeve (2), a buffer valve core (3) is installed in the inner cavity at the connection between the first outer sleeve (1) and the second outer sleeve (2), one end of the buffer valve core (3) is provided with a valve core large end (13), the valve core large end (13) cooperates with a large end installation cavity (11) arranged inside the first outer sleeve (1), and one end of the buffer valve core (3) is also provided with a bushing (4), the bushing (4) cooperates with a small end installation cavity (11) arranged inside the second outer sleeve (2). 2) are mounted in cooperation with each other, and a return spring (6) is installed between the large end (13) of the valve core and the end surface of the second outer sleeve (2), a shutoff hole (7) is provided in the radial direction of the buffer valve core (3), a valve core flow channel (8) is provided in the axial direction of the buffer valve core (3), and the inner cavity of the first outer sleeve (1), the valve core flow channel (8) and the inner cavity of the second outer sleeve (2) are all connected, a bypass pipeline (C) is connected to the end of the second outer sleeve (2), the bypass pipeline (C) is connected to the low-pressure return pipeline (B), and the bypass pipeline (C) between the bottom of the buffer pressure relief circuit (F) and the low-pressure return pipeline (B) is low-inlet and high-outlet.

2. The buffer pressure relief device for a descaling pump according to claim 1 is characterized in that: One end of the second outer sleeve (2) away from the bushing (4) is threadedly connected to a screw plug (5), and a screw plug channel (9) is provided on the screw plug (5).

3. The buffer pressure relief device for a descaling pump according to claim 2 is characterized in that: The thread plug (5) is provided with a thread plug interface (10), and the thread plug interface (10) is connected to the bypass pipeline (C).

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