Pressure balance type gas ultrasonic transducer

Abstract

A pressure balance type gas ultrasonic transducer comprises a shell. The shell is internally partitioned into a front chamber and a rear chamber, an elastic sound absorbing liner is arranged in the front chamber, a transducer sensitive element is mounted at the front end of the liner, the rear end of the liner extends to the bottom of the front chamber, a signal lead of the sensitive element penetrates through the liner to the rear chamber to be externally connected with a converter, a gap is reserved between the front portion of the liner and the wall of the front chamber, the rear portion of the liner is shrunk to form an inner cavity with the wall of the front chamber, and the wall of the inner cavity is provided with pressure balance holes through which the front chamber and the shell outside are communicated. The pressure balance holes and the gap between the shell and the linear form a pressure balance structure to lower differential pressure of the inner cavity of the transducer and fluid in a to-be-tested pipeline, excellent balance effects and sensitivity are achieved under the condition of frequent pressure changes, the pressure in the shell of the transducer is proximately kept to be the pipeline pressure, and consequently the sensitive element and an electrical element in the transducer can be protected, precision in sonic path distance of an ultrasonic flowmeter is guaranteed, and precision of a gas ultrasonic flowmeter is improved.

Description

technical field [0001] The invention relates to a gas ultrasonic flowmeter, in particular to a pressure-balanced gas ultrasonic transducer on a gas ultrasonic flowmeter. Background technique [0002] The front end of the transducer of the current gas ultrasonic flowmeter is equipped with a matching layer and a vibrator, and a mechanical seal plus a rubber seal is used. For example, a metal threaded sealing cover is added to the front end of the transducer shell, and a sealant is applied to the outer layer of the matching layer. , These sensitive components and electrical components are sealed in the transducer housing. However, such a mechanical seal plus a rubber seal will reduce the amplitude of the effective ultrasonic signal, and also reduce the proper matching degree of the matching layer. In order to ensure a good mechanical sealing effect, the compression degree of the metal seal is generally increased, and the interface of the rubber seal is prone to cracks, which w...

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Problems solved by technology

However, such a mechanical seal plus a rubber seal will reduce the amplitude of the effective ultrasonic signal, and also reduce the appropriate matching degree of the matching layer.

In order to ensure a good mechanical sealing effect, the compression degree of the metal seal is generally increased, and the interface of the rubber seal is prone to cracks, which will damage the sensitive components in the transducer under the pressure of the measured pipeline. ;When the pressure changes frequently or exceeds a certain range, the position of the sensitive element and the electrical element at the front end of the transducer will shift in the housing, and the fixed ultrasonic vibrator will shift together with the rubber lining of the matching layer, thus affecting An important parameter of the ultrasonic flowmeter - the size of the sound path, affects the accuracy of the flowmeter

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