A dry screw compressor dry gas seal leakage detection device

Abstract

This invention provides a dry gas seal leakage detection device for a dry screw compressor, relating to the field of dry gas seal technology. The invention includes a dry gas seal structure comprising a primary sealing gas system, a secondary sealing gas system, and an isolation gas system. The secondary sealing gas system includes a secondary sealing inlet pipe and a secondary sealing outlet pipe. The secondary sealing outlet pipe has a branch pipe and a main valve sequentially arranged in the airflow direction. A needle valve is installed on the branch pipe, and the end of the branch pipe is connected to a detection box containing ammonia water as a detection reagent. This invention allows for rapid determination of seal leakage, facilitating timely maintenance and repair.

Description

Technical Field

[0001] This utility model relates to the field of dry gas sealing technology, specifically to a dry gas seal leakage detection device for a dry screw compressor. Background Technology

[0002] Dry gas seals are non-contact end seals composed of a rotating ring, a stationary ring, a spring, a spring seat, a bushing, and a locating ring. A hydrodynamic groove is cut into the sealing surface of the rotating ring. When the rotating ring rotates at high speed, clean gas from the system enters the hydrodynamic groove. Upon encountering the sealing dam, the gas is pressurized, and the increased pressure creates a gap, forming a gas film approximately 3μm thick between the two end faces. The thrust generated by this gas film pushes the rotating and stationary rings apart, preventing the sealing end faces from contacting. The gas film has a certain stiffness; its stiffness is most stable when the closing force formed by the gas force and the spring force equals the gas film reaction force, thus achieving a sealing effect. The grooves on the rotating ring sealing surface mainly come in two forms: unidirectional spiral grooves and bidirectional spiral grooves.

[0003] A dry gas seal may leak under the following conditions:

[0004] 1. If the direction is reversed, the gas cannot enter the groove, and no gas film reaction force will be formed. The gap at the sealing end face cannot be formed, causing friction on the sealing surface. After the spiral groove wears down, the dry gas seal will leak.

[0005] 2. If the pressure in the inner sealing cavity is greater than the pressure in the outer sealing gas, the sealing gas forms an air film that opens the end face. The high-pressure medium inside then flows back into the sealing cavity, destroying the formed air film. If the sealing failure is not detected in time, it will cause contamination of the lubrication system.

[0006] Currently, in the polysilicon production process, each screw-type hydrogen compressor is equipped with four sets of dry gas sealing structures. If the secondary dry gas seal leaks in a certain part, the chlorosilane gas in the material gas will come into contact with the lubricating oil, causing lubricating oil contamination in the lubrication system. If the oil contamination is not detected in time, it will cause serious damage to the friction pairs of the unit, or even an operational accident. At the same time, the contaminated lubricating oil needs to be replaced, increasing operating costs. Utility Model Content

[0007] The purpose of this invention is to develop a dry gas seal leakage detection device for dry screw compressors that can quickly determine whether the seal is leaking, so as to carry out timely maintenance work.

[0008] This utility model is achieved through the following technical solution:

[0009] A dry gas seal leakage detection device for a dry screw compressor includes a dry gas seal structure, which comprises a primary sealing gas system, a secondary sealing gas system, and an isolation gas system. The secondary sealing gas system includes a secondary sealing inlet pipe and a secondary sealing outlet pipe, wherein:

[0010] The secondary sealed exhaust pipe is provided with a branch pipe and a main valve in sequence in the direction of airflow. The branch pipe is equipped with a needle valve, and the end of the branch pipe is connected to a detection box, which contains ammonia water as a detection reagent.

[0011] Optionally, the testing box is equipped with a reagent box, and the testing reagents are placed inside the reagent box.

[0012] Optionally, the reagent box is provided with a conduit at the top, and a through hole communicating with the conduit is opened on the top surface of the reagent box at the bottom end of the conduit. The end of the branch pipe extends into the detection box and is located on the upper side of the conduit.

[0013] Optionally, the tubing and reagent box contain a columnar sponge, the bottom end of which is provided with a support connected to the bottom of the reagent box, and the top end of the sponge extends to the top end of the tubing.

[0014] Optionally, the testing box is made of transparent material, and the top of the testing box is provided with an openable top cover.

[0015] Optionally, the detection box is connected to an air outlet pipe, and a filter and a flame arrester are sequentially installed on the air outlet pipe.

[0016] Optionally, the detection box is equipped with a photoelectric sensor, and the transmitting and receiving parts of the photoelectric sensor are located on the opposite side walls of the two detection boxes.

[0017] Optionally, the photoelectric sensor is located at the top of the conduit, and the light signal emitted by the emitting part is received by the receiving part above the top of the conduit.

[0018] The beneficial effects of this utility model are:

[0019] This invention detects leaks in the sealing gas of a two-stage sealing gas system by passing the sealing gas through ammonia water. Utilizing the characteristic that ammonia water produces white smoke upon contact with chlorosilane, leaks in the sealing gas can be detected in a timely manner, allowing for prompt maintenance. Detection can be performed manually by eye or automatically using photoelectric sensors. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a structural diagram of the present utility model;

[0022] Figure 2 This is a structural diagram of the testing box.

[0023] Reference numerals: 1. Secondary sealed air inlet pipe; 2. Secondary sealed air outlet pipe; 3. Main valve; 4. Branch pipe; 5. Needle valve; 6. Detection box; 7. Top cover; 8. Reagent box; 9. Tubing; 10. Support; 11. Sponge; 12. Photoelectric sensor; 13. Air outlet pipe; 14. Filter; 15. Flame arrester. Detailed Implementation

[0024] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0025] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0026] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0028] like Figure 1 and Figure 2As shown, this utility model discloses a dry gas seal leakage detection device for a dry screw compressor, including a dry gas seal structure. The dry gas seal structure includes an inner primary sealing gas system, a middle secondary sealing gas system, and an outer isolation gas system. The primary sealing gas system includes a primary sealing inlet pipe and a primary sealing exhaust pipe. The secondary sealing gas system includes a secondary sealing inlet pipe 1 and a secondary sealing exhaust pipe 2. The isolation gas system includes an isolation gas inlet pipe. Hydrogen is used as the sealing gas in the primary sealing gas system, and nitrogen is used as the sealing gas in the secondary sealing gas system and the isolation gas system. The sealing gas pressure of the primary sealing gas system, the secondary sealing gas system, and the isolation gas system gradually decreases. The dry gas seal structure is existing technology and will not be described in detail.

[0029] The secondary sealing exhaust pipe 2 is provided with a branch pipe 4 and a main valve 3 in the direction of airflow. The branch pipe 4 is connected to the secondary sealing exhaust pipe 2. When the sealing gas of the secondary sealing gas system flows in the secondary sealing exhaust pipe 2, it first passes through the branch pipe 4 and then through the main valve 3. A needle valve 5 is provided on the branch pipe 4.

[0030] The branch pipe 4 is connected to a detection box 6 at one end. The top of the detection box 6 has an openable top cover 7. A reagent box 8 is placed inside the detection box 6. The detection box 6 is made of transparent material. A vertically arranged conduit 9 is located on the top of the reagent box 8. A through hole communicating with the conduit 9 is opened on the top surface of the reagent box 8 at the bottom of the conduit 9. A sponge 11 is placed inside the conduit 9 and the reagent box 8. The sponge 11 is cylindrical and smaller than the conduit 9. The sponge 11 is vertically arranged. A support 10 connected to the bottom of the reagent box 8 is located at the bottom of the sponge 11. The top of the sponge 11 extends to the top of the conduit 9. The reagent in the reagent box 8 is ammonia water. The sponge 11 is made of alkali-resistant materials such as EPDM rubber or nitrile rubber.

[0031] The end of the branch pipe 4 extends into the detection box 6, and the end of the branch pipe 4 is located on the upper side of the conduit 9. The airflow entering the detection box 6 through the branch pipe 4 passes through the top of the conduit 9.

[0032] The detection box 6 is equipped with a photoelectric sensor 12, which is located at the top of the conduit 9. The emitting part and the receiving part of the photoelectric sensor 12 are located on the side walls of the two opposite detection boxes 6. The light signal emitted by the emitting part is received by the receiving part after passing through the top of the conduit 9.

[0033] The test box 6 is also connected to an air outlet pipe 13, on which a filter 14 and a flame arrester 15 are sequentially installed.

[0034] The detection chamber 6 can detect whether the sealing gas discharged from the secondary sealed exhaust pipe 2 contains chlorosilane gas. During detection, the main valve 3 is closed and the needle valve 5 is opened, allowing the sealing gas to enter the detection chamber 6 through the branch pipe 4. When the primary and secondary sealing gas systems fail, the material gas will enter the secondary sealing gas system, and the chlorosilane in the material gas will mix into the sealing gas discharged from the secondary sealed exhaust pipe 2. After entering the detection chamber 6, the sealing gas is located at the top of the conduit 9. When the ammonia water in the conduit 9 comes into contact with the chlorosilane, it produces white smoke. The white smoke consists of ammonium chloride solid particles. The white smoke is located between the transmitter and receiver of the photoelectric sensor 12, which will change the photoelectric signal received by the receiver of the photoelectric sensor 12. The photoelectric sensor 12 can determine whether white smoke is produced, thereby determining whether chlorosilane is present in the sealing gas. Ultimately, this achieves the purpose of rapid detection of the dry gas sealing structure, so as to carry out timely maintenance and avoid more serious consequences. The detection chamber 6 is made of transparent material, and the white smoke can also be detected by manual visual inspection. The gas and white smoke inside the detection chamber 6 are discharged after passing through the filter 14 and flame arrester 15 of the exhaust pipe 13. The main valve 3 and needle valve 5 can be electrically controlled valves or pneumatic valves, which can realize automatic timed opening and closing to achieve the purpose of timed detection. The photoelectric signal generated by the photoelectric sensor 12 can be transmitted to the central control system or monitoring room by wired or wireless means so that personnel can be informed in a timely manner.

[0035] This invention detects a leak in the sealing gas of a two-stage sealing gas system by drawing out the sealing gas through ammonia water. Utilizing the characteristic that ammonia water produces white smoke upon contact with chlorosilane, it can promptly detect whether a leak has occurred, allowing for timely maintenance and repair. During detection, it can be performed manually by visual inspection or automatically by using a photoelectric sensor 12.

[0036] The above embodiments are merely preferred embodiments of this utility model and are not intended to limit the technical solutions of this utility model. Any technical solution that can be implemented based on the above embodiments without creative effort should be considered to fall within the scope of protection of this utility model patent.

Claims

1. A dry gas seal leakage detection device for a dry screw compressor, characterized in that, The system includes a dry gas sealing structure, comprising a primary sealing gas system, a secondary sealing gas system, and an isolation gas system. The secondary sealing gas system includes a secondary sealing inlet pipe and a secondary sealing exhaust pipe, wherein: The secondary sealed exhaust pipe is provided with a branch pipe and a main valve in sequence in the direction of airflow. The branch pipe is equipped with a needle valve, and the end of the branch pipe is connected to a detection box, which contains ammonia water as a detection reagent.

2. The dry gas seal leakage detection device for a dry screw compressor according to claim 1, characterized in that, The testing box contains a reagent box, and the testing reagents are placed inside the reagent box.

3. The dry gas seal leakage detection device for a dry screw compressor according to claim 2, characterized in that, The reagent box is equipped with a conduit at the top, and a through hole communicating with the conduit is opened on the top surface of the reagent box at the bottom of the conduit. The end of the branch pipe extends into the detection box and is located on the upper side of the conduit.

4. The dry gas seal leakage detection device for a dry screw compressor according to claim 3, characterized in that, The tubing and reagent box contain columnar sponges, with a support at the bottom of the sponge connected to the bottom of the reagent box, and the top of the sponge extending to the top of the tubing.

5. The dry gas seal leakage detection device for a dry screw compressor according to claim 1, characterized in that, The testing box is made of transparent material, and the top of the testing box has an openable top cover.

6. The dry gas seal leakage detection device for a dry screw compressor according to claim 1, characterized in that, The testing box is connected to an air outlet pipe, and a filter and a flame arrester are sequentially installed on the air outlet pipe.

7. The dry gas seal leakage detection device for a dry screw compressor according to claim 3, characterized in that, The detection box is equipped with a photoelectric sensor, and the transmitting and receiving parts of the photoelectric sensor are located on the two opposite side walls of the detection box.

8. The dry gas seal leakage detection device for a dry screw compressor according to claim 7, characterized in that, The photoelectric sensor is located at the top of the conduit, and the light signal emitted by the emitting part is received by the receiving part above the top of the conduit.

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