Sonic Nozzle Assemblies for Gas Flow Control in Vacuum Environments

Abstract

The invention discloses a sound speed nozzle assembly applied to control gas flow in the vacuum environment. The sound speed nozzle assembly comprises an air inlet pipe, a temperature measurement nozzle, a pressure measurement nozzle, an air current stabilizing pipe, a sound speed nozzle spherical joint, an outer sleeved nut and a welding filler neck, wherein one end of the air current stabilizing pipe is fixedly connected with the air inlet pipe, the other end of the air current stabilizing pipe is fixedly connected with the sound speed nozzle spherical joint, a temperature measurement hole and a pressure measurement hole are formed in the air current stabilizing pipe, the temperature measurement nozzle and the pressure measurement nozzle are fixedly connected to the temperature measurement hole and the pressure measurement hole respectively, and the other end of the sound speed nozzle spherical joint is fixedly connected with the welding filler neck through the outer sleeved nut. The sound speed nozzle assembly is integrally made of stainless steel materials, and a sound speed nozzle and a spherical joint are integrally machined and formed. Compared with a conventional sound speed nozzle assembly, the sound speed nozzle assembly is simple in process, the number of sealed faces is decreased from four to one, the sphere of the spherical joint and the conical surface of the welding filler neck form line sealing, the reliability is greatly improved, and the sound speed nozzle assembly can be used in the vacuum and low-temperature environment in a continuous and long-term mode.

Description

technical field [0001] The invention relates to a sonic nozzle assembly used in vacuum environment gas flow control and belongs to the technical field of gas flow control. Background technique [0002] Using a sonic nozzle to control gas flow is a simple, reliable, and fast-response method. When the gas flow velocity at the throat of the sonic nozzle reaches the local sound velocity, the flow through the nozzle reaches the maximum and is not affected by the pressure fluctuation downstream of the nozzle. by the formula Calculate the flow through the sonic nozzle. Among them, q max is flow rate; C d is the flow coefficient; k is specific heat ratio, R is gas constant; p * is the total gas pressure in front of the sonic nozzle; T * is the total temperature of the gas, A t is the cross-sectional area of ​​the nozzle throat. In general, the total gas temperature T * , the specific heat ratio k remains unchanged, therefore, only need to adjust and measure the total gas...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the problem of poor sealing effect and low reliability of conventional sonic nozzles in a vacuum environment, and proposes a structure in which the sonic nozzle and the spherical joint are integrally processed and formed using a spherical-cone sealing form Reliable wire sealing reduces the number of sealing surfaces; the overall use of stainless steel improves processability and weldability, and can be used continuously for a long time in vacuum and low temperature environments

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