High internal pressure ratio casing structure of screw compressor

Abstract

This utility model relates to the field of screw compressor technology, specifically to a high internal pressure ratio screw compressor housing structure that can measure the rotor clearance at the discharge port when the internal and external high pressure ratios are matched. It includes a compressor housing, within which a rotor cavity is provided, housing a female rotor and a male rotor. The characteristic feature is that an integrally formed platform is provided above the discharge port of the compressor housing. A through hole is formed on the platform, and a flange cover with a shaft is provided to seal the through hole. The shaft of the flange cover extends into the through hole, and its end is a curved surface that mates with the inner wall of the rotor cavity.

Description

Technical Field

[0001] This utility model relates to the field of screw compressor technology, specifically to a casing structure for a screw compressor with a high internal pressure ratio. Background Technology

[0002] Screw compressors, as rotary positive displacement compressors, are widely used in process gas compression and process flow applications. The matching relationship between the internal and external pressure ratios of a screw compressor is one of the core factors affecting its efficiency. However, under operating conditions with a high external pressure ratio: if the main unit's discharge port is designed for a high internal pressure ratio, the discharge port will be very small, typically with an axial length distance ≤25mm and a radial length distance ≤60mm (e.g., Figure 1 As shown in the figure, this distance is insufficient to insert the feeler gauge from below the housing to measure the rotor clearance; if the main unit outlet is not designed with a high internal pressure ratio, the internal and external pressure ratios will not be perfectly matched, resulting in energy loss. Summary of the Invention

[0003] To solve the above-mentioned technical problems, this utility model provides a casing structure for a screw compressor with a high internal pressure ratio, which can measure the rotor clearance at the discharge port when the internal and external high pressure ratios are matched.

[0004] The technical solution is as follows: a high internal pressure ratio screw compressor housing structure, comprising a compressor housing, a rotor cavity provided inside the compressor housing, and a female rotor and a male rotor provided inside the rotor cavity, characterized in that an integrally formed platform is provided above the discharge port of the compressor housing, a through hole is opened on the platform and a shaft flange cover is provided to seal the through hole, the shaft of the shaft flange cover extends into the through hole and the end is a curved surface that mates with the inner wall of the rotor cavity.

[0005] A further feature is that an O-ring is provided between the flange cover with shaft and the platform; Let L be the distance between the wall of the through hole closest to the exhaust end face and the exhaust end face, D be the nominal diameter of the rotor, and α be the exhaust angle of the female rotor. d The corresponding arc length is L1, and the female rotor lead is T. f L satisfies 0 < L < (L1 / (πD / T)) f )) / 2; The curved surface of the shaft end of the flange cover is concave (0.02~0.05) mm relative to the curved surface of the inner wall of the rotor cavity.

[0006] With this invention, for casings with high internal pressure ratios, a feeler gauge can be inserted directly into the opening above the casing outlet to measure the clearance of the rotor at the exhaust end. The area above the rotor is a low-pressure zone, and a flange cover with a shaft ensures good sealing. At the same time, it can also ensure that the internal and external pressure ratios are matched and are both high pressure ratios, and the gas can be discharged smoothly, reducing energy loss and improving efficiency. Attached Figure Description

[0007] Figure 1 Here is a diagram showing the unfolded spiral of the existing exhaust port; Figure 2 This is a schematic diagram of the structure of this utility model; Figure 3 This is a schematic diagram of the casing opening structure of this utility model (top view). Figure 4 This is a schematic diagram showing the parameters required for the length L in this utility model; Figure 5 This is a schematic diagram of the structure of the flange cover with shaft of this utility model; Figure 6 for Figure 2 Sectional view along the AA direction; Figure 7 for Figure 6 Enlarged diagram of point B in the middle. Detailed Implementation

[0008] See Figures 2 to 7 As shown, a high internal pressure ratio screw compressor housing structure includes a compressor housing 1, a rotor cavity 2 inside the compressor housing 1, and a female rotor and a male rotor inside the rotor cavity 2. An integrally formed platform 4 is provided above the discharge port of the compressor housing 1. A through hole 5 is provided on the platform 4, and a shaft-mounted flange cover 3 is provided to seal the through hole. The diameter of the through hole 5 is d, where d ≥ 120 mm. The shaft 6 of the shaft-mounted flange cover 3 extends into the through hole 5, and its end is a curved surface that mates with the inner wall of the rotor cavity 2. To ensure sealing, an O-ring 7 is provided between the shaft-mounted flange cover 3 and the platform 4.

[0009] To facilitate the insertion of the feeler gauge into the measurement position, let L be the distance between the wall of the through hole closest to the exhaust end face and the exhaust end face. The length of L should be as small as possible while ensuring that platform 4 can be arranged on the compressor housing 1. The size of platform 4 is only required to accommodate the flange cover 3 with shaft. Let the nominal diameter of the rotor be D, the exhaust angle of the female rotor be αd, and the corresponding arc length be L1 (see...). Figure 4 (In the figure, δ represents a fixed angle under different line types), and the female rotor lead is T. f L satisfies 0 < L < (L1 / (πD / T)) f )) / 2.

[0010] Let the radius of the rotor cavity 2 be R, and the radius of the curved surface at the end of the shaft 6 with the shaft flange cover 3 be R + (0.02~0.05). When the shaft flange cover 2 covers the through hole 5, the curved surface at the end of the shaft 6 is concave by 0.02-0.05mm relative to the curved surface of the inner wall of the rotor cavity 2 to ensure safety.

Claims

1. A high internal pressure ratio casing structure for a screw compressor, comprising a compressor casing, wherein a rotor cavity is disposed within the compressor casing, and a female rotor and a male rotor are disposed within the rotor cavity, characterized in that, The compressor housing has an integrally formed platform above the discharge port. The platform has a through hole and a flange cover with a shaft that seals the through hole. The shaft of the flange cover extends into the through hole and its end is a curved surface that mates with the inner wall of the rotor cavity.

2. The casing structure of a screw compressor with a high internal pressure ratio according to claim 1, characterized in that, An O-ring is provided between the flange cover with shaft and the platform.

3. The casing structure of a screw compressor with a high internal pressure ratio according to claim 1, characterized in that, Let L be the distance between the wall of the through hole closest to the exhaust end face and the exhaust end face, D be the nominal diameter of the rotor, and α be the exhaust angle of the female rotor. d The corresponding arc length is L1, and the female rotor lead is T. f L satisfies 0 < L < (L1 / (πD / T)) f )) / 2.

4. The casing structure of a screw compressor with a high internal pressure ratio according to claim 1, characterized in that, The curved surface of the shaft end of the flange cover is concave (0.02~0.05) mm relative to the curved surface of the inner wall of the rotor cavity.

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