Dry type screw main engine exhaust pipe assembly with cooling and noise reduction functions
By designing a combination of exhaust pipe and silencer pipe with a double-wall structure, the problems of high exhaust temperature and high noise in dry screw compressors were solved, achieving noise reduction and cooling effects, and improving the life of seals and exhaust efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-09
- Publication Date
- 2026-03-31
AI Technical Summary
Dry screw compressors have high exhaust temperatures during compression, which reduces the lifespan of seals and causes loud noise. Existing noise reduction solutions are costly and ineffective.
Design an exhaust pipe with a double-wall structure, with an internal silencer pipe composed of a perforated plate and a conical baffle. The gas flow path is divided into multiple chambers. Cooling water flows in the jacket in the opposite direction to the gas flow, using counter-current heat exchange for cooling, and the perforated plate structure absorbs noise.
It effectively reduces exhaust pipe noise, improves the lifespan of seals, and lowers exhaust temperature through jacket cooling, thereby enhancing exhaust efficiency and system stability.
Smart Images
Figure CN224064521U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of dry screw compressor technology, and in particular to a dry screw compressor exhaust pipe assembly with cooling and noise reduction functions. Background Technology
[0002] In the field of dry screw compressors, the dry screw compressor unit does not involve cooling oil during compression. Furthermore, to improve volumetric efficiency, the screw rotor speed can typically reach tens of thousands of revolutions per minute. Due to the short time and high speed of gas compression, it is almost an adiabatic process, resulting in very high exhaust temperatures. This high temperature, transferred to the exhaust pipe, reduces the lifespan of rubber seals, and accidental contact with the hot exhaust pipe can cause burns. When the gas flows at high speed within the compression chamber, pressure pulsations and turbulence (especially near the exhaust port) generate high-frequency noise. When high-pressure gas is suddenly discharged into the pipe, the rapid expansion of the airflow produces a popping sound. Therefore, dry screw compressor units generate significant noise during operation. Existing noise reduction solutions generally involve using thickened exhaust pipes or covering the exhaust pipes with sound-absorbing materials. However, thickened pipes are usually non-standard, difficult to procure, and expensive, with poor noise reduction capabilities. Covering the exhaust pipes with sound-absorbing materials significantly impacts heat dissipation.
[0003] In light of this, engineers in the field have dedicated themselves to developing an exhaust pipe assembly with cooling and noise reduction functions. Utility Model Content
[0004] The purpose of this utility model is to overcome the shortcomings of existing technologies and provide a dry screw compressor exhaust pipe assembly with cooling and noise reduction functions, which solves the problems of poor noise reduction function, high exhaust temperature, and short life of exhaust pipe assembly seals.
[0005] This utility model is achieved through the following technical solution:
[0006] A dry screw compressor exhaust pipe assembly with cooling and noise reduction functions includes an exhaust pipe and a silencer pipe. The exhaust pipe has a double-walled structure with a hollowed-out interlayer in the middle. The outer channel is a liquid channel, and the outer surface of the exhaust pipe has a water inlet and a water outlet. The inner surface is the air intake and exhaust channel, with an air inlet and an exhaust outlet at each end. The silencer pipe is installed inside the air intake and exhaust channel of the exhaust pipe. The silencer pipe includes a seamless steel pipe, a baffle, a circular baffle, a second baffle, a second seamless steel pipe, and a second circular baffle. The upper half of the seamless steel pipe has an elliptical hole circumferentially, and the lower half has a circular through hole. The first baffle is welded to the seamless steel pipe. The seamless steel pipe is located at the boundary between the elliptical through hole and the circular through hole 1 on the outside. The upper and lower halves of the seamless steel pipe 2 are respectively provided with circular through holes 2 and 3 on the circumference, and the diameter of the circular through hole 3 is smaller than the diameter of the circular through hole 2. The baffle 2 is welded to the outside of the seamless steel pipe 2 and is located at the boundary between the circular through holes 2 and 3. The central area of the circular baffle 1 and the circular baffle 2 is a solid structure, and several small holes are evenly distributed on the outer side of the central area. The lower end of the seamless steel pipe 1 is welded to the central solid structure of the circular baffle 1, the upper end of the seamless steel pipe 2 is welded to the central solid structure of the other side of the circular baffle 1, and the lower end of the seamless steel pipe 2 is welded to the central solid structure of the circular baffle 2.
[0007] The two ends of the muffler are respectively fixed in the intake and exhaust channels of the exhaust pipe by retaining rings.
[0008] Both the first baffle and the second baffle are conical plates, with the first baffle having a cone angle of 40 degrees and the second baffle having a cone angle of 60 degrees.
[0009] The diameters of the three circular through holes on the silencer tube decrease sequentially, while the total effective area of all the circular through holes increases sequentially, with an increase ratio of 1.2-1.3 times.
[0010] The axial spacing between the upper baffle, the first circular baffle, the second baffle, and the second circular baffle of the silencer pipe increases sequentially from top to bottom, with an increase ratio of 1.2-1.3 times.
[0011] All exposed surfaces of the exhaust pipe are treated with electrophoresis.
[0012] The cooling water flow direction inside the exhaust pipe is opposite to the flow direction of the high-temperature, high-pressure gas inside.
[0013] Stainless steel is preferred for all parts.
[0014] The advantages of this utility model are:
[0015] 1. The present invention has an internal silencer pipe that effectively reduces noise, and an exhaust pipe with a sandwich structure that greatly reduces noise transmission, thus solving the problem of high exhaust noise in dry screw compressors.
[0016] The exhaust pipe of this utility model has a jacketed structure. The cooling medium flows from the jacket and can effectively cool the high-temperature gas in the exhaust pipe, thus solving the problem of high exhaust temperature of dry screw compressor main unit.
[0017] 3. The cooling medium inside the exhaust pipe jacket of this utility model not only cools the high-temperature gas inside but also cools the exhaust pipe itself, thus solving the problem of short service life of rubber seals due to high temperature. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the exhaust pipe structure;
[0019] Figure 2 This is a schematic diagram of the silencer pipe structure;
[0020] Figure 3 This is a schematic diagram of the exhaust pipe assembly;
[0021] Figure 4 This is a schematic diagram of the exhaust pipe assembly divided into sections AA;
[0022] Figure 5 This is a schematic diagram of the BB section of the silencer pipe;
[0023] The serial numbers in the diagram are labeled as follows:
[0024] 1-Exhaust pipe, 2-Silencer pipe, 3-Snap ring, 4-Water inlet, 5-Drain outlet, 6-Air inlet, 7-Exhaust outlet, 201-Seamless steel pipe one, 202-Baffle one, 203-Circular baffle one, 204-Baffle two, 205-Seamless steel pipe two, 206-Circular baffle two, 207-Oval hole, 208-Circular through hole one, 209-Circular through hole two, 210-Circular through hole three, 211-First chamber, 212-Second chamber, 213-Third chamber. Detailed Implementation
[0025] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer and more understandable, the above technical solution will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for the purpose of describing this utility model in detail and should not be used to limit the scope of protection of this utility model.
[0026] In the exhaust system of a dry screw compressor, the inlet of exhaust pipe 1 is generally installed and fixed at the exhaust port of the dry screw compressor main unit. The exhaust port of exhaust pipe 1 is generally connected to the after-treatment equipment and sealed with O-rings or gaskets to prevent pressurized gas leakage.
[0027] like Figure 1 , 4 As shown, the outer surface of the exhaust pipe 1 is provided with a water inlet 4 and a drain outlet 5, and the inner surface is an air intake and exhaust channel. The two ends are an air intake 6 and an exhaust outlet 7. The muffler pipe 2 is inserted into the gas flow channel of the exhaust pipe 1 through the exhaust outlet 7 and is fixed by the retaining ring 3.
[0028] like Figure 2 , 3 As shown in Figure 4, the muffler pipe 2 is installed inside the intake and exhaust channels of the exhaust pipe 1. The muffler pipe 2 includes a seamless steel pipe 201, a baffle 202, a circular baffle 203, a baffle 204, a seamless steel pipe 205, and a circular baffle 206. The upper half of the seamless steel pipe 201 has an elliptical hole 207 circumferentially, and the lower half has a circular through hole 208 circumferentially. The baffle 202 is welded to the outside of the seamless steel pipe 201 and is located at the boundary between the elliptical through hole 207 and the circular through hole 208. The upper and lower halves of the seamless steel pipe 205 have a circular through hole 209 and a circular through hole 210 circumferentially, respectively, and the diameter of the circular through hole 210 is smaller than the diameter of the circular through hole 209. The second baffle 204 is welded to the outside of the second seamless steel pipe 205 and is located at the boundary between the second circular through hole 209 and the third circular through hole 210; the central areas of the first circular baffle 203 and the second circular baffle 206 are solid structures, and several small holes are evenly distributed on the outer side of the central areas; the lower end of the first seamless steel pipe 201 is welded to the solid structure in the center of the first circular baffle 203; the upper end of the second seamless steel pipe 205 is welded to the solid structure in the center of the other side of the first circular baffle 203; and the lower end of the second seamless steel pipe 205 is welded to the solid structure in the central area of the second circular baffle 206.
[0029] like Figure 2 , 3 As shown in Figure 4, the gas intake passage of the exhaust pipe 1 is divided into several chambers by the muffler pipe 2, which also limits the gas flow path. The chamber between baffle 1 202 and circular baffle 1 203 is the first chamber 211, the chamber between circular baffle 1 203 and baffle 2 204 is the second chamber 212, and the chamber between baffle 2 204 and circular baffle 2 206 is the third chamber 213. Figure 4As shown in the schematic diagram of the gas flow path, when the high-temperature pressure gas from the outlet of the dry screw compressor enters the internal channel of the exhaust pipe 1, the gas first needs to enter the seamless steel pipe 201 through the elliptical hole 207 in the upper half of the seamless steel pipe 201 from the inlet 6. Since the central area of the circular baffle 203 welded to the seamless steel pipe 201 is a solid structure, the gas in the seamless steel pipe 201 can only enter the first chamber 211 through the circular through-hole in the lower half of the seamless steel pipe 201. The gas inside chamber 1 enters the second chamber 212 through the small hole on the circular baffle 203. The gas in the second chamber 212 then enters the seamless steel pipe 205 through the circular through hole 209 in the upper half of the seamless steel pipe 205. Since the central area of the circular baffle 206 welded to the seamless steel pipe 205 is a solid structure, the gas in the seamless steel pipe 205 can only enter the third chamber 213 through the circular through hole 310 in the lower half of the seamless steel pipe 205. The gas in the third chamber 213 is discharged through the small hole on the circular baffle 206.
[0030] Both baffle 1 202 and baffle 2 204 are conical plates, with the cone angle of baffle 1 202 being 40 degrees and the cone angle of baffle 2 204 being 60 degrees.
[0031] The diameters of the circular through holes 208, 209, and 210 on the silencer tube 2 decrease sequentially, while the total effective area of all the circular through holes increases sequentially, with an increase ratio of 1.2-1.3 times.
[0032] The axial spacing between the upper baffle 202, the circular baffle 203, the second baffle 204, and the second circular baffle 206 of the silencer pipe 2 increases sequentially from top to bottom, with an increase ratio of 1.2-1.3 times.
[0033] All exposed surfaces of the exhaust pipe 1 are treated with electrophoresis.
[0034] The flow direction of the cooling water in the exhaust pipe 1 is opposite to the flow direction of the high-temperature and high-pressure gas inside.
[0035] Stainless steel is preferred for all parts.
[0036] Preferably, the cooling water flow direction of the jacket of the exhaust pipe 1 is opposite to the flow direction of the internal high-temperature pressure gas. The stable counter-current temperature difference makes the temperature gradient of the cold and hot fluids more uniform throughout the heat exchange process, resulting in higher heat exchange efficiency.
[0037] The exhaust pipe 1 is electrophoretically treated on all surfaces, and the muffler pipe 2 is made of stainless steel, which effectively isolates the parts from the influence of corrosive media such as air, water vapor, and water, thus effectively increasing the service life of the parts.
[0038] The gas passage of exhaust pipe 1 is divided into several chambers by muffler pipe 2, which lengthens the gas flow path and also requires the gas to flow near the inner wall of the gas passage of exhaust pipe 1, which allows the gas to exchange heat more fully and improves the cooling effect of the gas.
[0039] The gas at the air inlet 6 of exhaust pipe 1 is close to the exhaust port of the dry screw compressor. When the high-pressure gas is instantly discharged into the pipe, the airflow velocity is extremely high, which usually generates high-frequency noise. The diameter of the silencer holes along the gas flow path decreases from large to small, which greatly enhances the absorption efficiency of high-frequency noise. The double-walled sandwich structure of exhaust pipe 1 has short wavelengths of high-frequency sound waves, which are easily reflected and absorbed by the double-walled sandwich structure, thus providing double noise reduction protection for high-frequency noise.
[0040] like Figure 5 As shown, the preferred order is L3 > L2 > L1, with the first, second, and third chambers gradually increasing in size. The change in cross-section causes sound wave reflection, and some sound waves cancel each other out. Different sized chambers correspond to different resonant frequencies, which can effectively improve the noise reduction effect in the mid and low frequencies. The gradually increasing chambers can also reduce airflow disturbance, reduce airflow separation and turbulence, improve system stability, and increase exhaust efficiency.
[0041] like Figure 4 , Figure 5 As shown, both baffle 202 and baffle 204 on the silencer tube are conical, which can cause the cross-sectional area of the chamber to change gradually, resulting in a continuous change in the acoustic impedance (the ratio of sound pressure to volume flow velocity) along the sound wave propagation path, generating partial sound wave reflection and phase shift, which leads to multiple interference attenuations of sound energy in the expansion chamber.
[0042] The most significant feature of this invention is the simple structure of the exhaust pipe assembly. After the perforated plate pre-attenuates the mid-to-high frequencies, the expansion chamber is optimized for low frequencies, forming a wide-band noise reduction. This breaks through the frequency band limitations of traditional single structures, taking into account both high and low frequency noise elimination. It can also effectively cool high-temperature gases, indirectly improving the stability of the gas in the exhaust pipe and increasing exhaust efficiency.
[0043] The above description is only a preferred embodiment of this utility model. Any improvements or modifications made to the structure without innovative changes, provided they do not deviate from the principle of this utility model, shall fall within the protection scope of this patent.
Claims
1. A dry screw mainframe exhaust pipe assembly having cooling and silencing functions, characterized by: The exhaust pipe is a double-wall structure, the outer channel is a liquid channel, the outer surface is provided with a water inlet and a drain, the inner channel is an air inlet and outlet channel, the air inlet and outlet channel is provided with an air inlet and an air outlet at both ends, and the muffler pipe is installed in the air inlet and outlet channel of the exhaust pipe.
2. A dry screw mainframe exhaust pipe assembly with cooling and silencing function according to claim 1, characterized in that: The two ends of the muffler pipe are fixed in the air inlet and outlet channel of the exhaust pipe through a snap ring.
3. A dry screw mainframe exhaust pipe assembly with cooling and silencing function according to claim 1, characterized in that: The baffle one and the baffle two are both conical plates, the cone angle of the baffle one is 40 degrees, and the cone angle of the baffle two is 60 degrees.
4. A dry screw mainframe exhaust pipe assembly with cooling and silencing function according to claim 1, characterized in that: The diameters of the circular through hole one, the circular through hole two and the circular through hole three on the muffler pipe decrease in turn, and the total effective area of all the circular through holes increases in turn by 1.2-1.3 times.
5. A dry screw mainframe exhaust pipe assembly with cooling and silencing function according to claim 1, characterized in that: The axial spacing of the baffle one, the circular baffle one, the baffle two and the circular baffle two on the muffler pipe increases in turn from top to bottom by 1.2-1.3 times.
6. A dry screw mainframe exhaust pipe assembly with cooling and silencing function according to claim 1, characterized in that: All exposed surfaces of the exhaust pipe are electrophoretic treated.
7. A dry screw mainframe exhaust pipe assembly with cooling and silencing function according to claim 1, characterized in that: The cooling water flow direction in the exhaust pipe is opposite to the internal high-temperature pressure gas flow direction.