CN212340342U - Outer formula high temperature type ultrasonic sensor that presss from both sides - Google Patents

Abstract

The utility model relates to an outer formula high temperature type ultrasonic sensor that presss from both sides belongs to the sensor field. The sound guide module is made of polyether-ether-ketone, a layer of metal film is electroplated on the outer surface of the sound guide module, a wafer positioning groove forming an included angle of 45 degrees with a horizontal axis is formed in the sound guide module, the piezoelectric ceramic wafer is adhered in the wafer positioning groove through epoxy resin, high-elasticity electronic pouring sealant is filled in a gap on the back surface of the piezoelectric ceramic wafer, a throat hoop positioning groove is formed in the upper portion of the sound guide module, and a circular-arc-shaped pipeline binding surface is arranged below the sound guide module. The piezoelectric ceramic wafer adopts a single-side lead wire, the lead wire is welded on a pin of a wiring terminal, a junction box is fixed on a sound guide module above the electronic pouring sealant, and a signal cable enters the junction box through a waterproof joint and is connected with the wiring terminal. The utility model discloses ultrasonic signal energy loss is little, and is high temperature resistant and can block the heat transfer, effectively shields outside electromagnetic interference signal, simple structure, simple to operate are applicable to the pipeline of various bores.

Description

Outer formula high temperature type ultrasonic sensor that presss from both sides

Technical Field

The utility model relates to an ultrasonic sensor field, a formula of outer clamp high temperature type ultrasonic sensor is explained in detail.

Background

As is well known, an ultrasonic flowmeter calculates a flow rate by measuring a difference between forward and backward velocities of ultrasonic pulses in a fluid to reflect a flow velocity of the fluid using a propagation velocity difference method. The ultrasonic flowmeter is a non-contact measuring instrument, and an external clamp type ultrasonic sensor is directly bound on the outer wall of a measured pipeline, so that the ultrasonic flowmeter has the characteristics of no change of the flowing state of fluid, no pressure loss, no need of pipe breakage and production stop, and simple installation, and can be used for measuring the flow of strong corrosivity, non-conductivity, high temperature and high pressure, flammability and explosiveness and radioactive fluid which are difficult to measure by other types of instruments.

The ultrasonic sensor is used as a core component, and the performance index of the ultrasonic sensor directly influences the measurement accuracy and stability of the ultrasonic flowmeter. In the existing external clamping type ultrasonic sensor technology, a piezoelectric ceramic wafer is directly adhered to a sound wedge, and the sound wedge is generally made of polysulfone material. Due to the physical characteristics of the material, the material has poor temperature resistance and low sound conductivity at high temperature. The sensor does not adopt a heat dissipation measure, heat is conducted to the piezoelectric ceramic wafer through the acoustic wedge, the temperature aging of the piezoelectric ceramic wafer is accelerated, and the permittivity, the dielectric loss and the electromechanical coupling coefficient are reduced along with the temperature rise. The attenuation of the transmitting and receiving signals is large at high temperature, the waveform is distorted, the measurement precision is reduced, and even the measurement cannot be stable. Therefore, the sensor can only measure the fluid below 90 ℃, and the application range is limited.

Disclosure of Invention

In order to overcome the not enough of prior art, the utility model provides an outer formula high temperature type ultrasonic sensor that presss from both sides, ultrasonic signal energy loss is little, and high temperature resistant and can block the heat transfer, effectively shield outside electromagnetic interference signal, simple structure, simple to operate are applicable to the pipeline of various bores.

The utility model provides a technical scheme that its technical problem adopted is: the externally-clamped high-temperature ultrasonic sensor is provided with a sound guide module and is characterized in that the sound guide module is made of polyether-ether-ketone, a metal film is electroplated on the outer surface of the sound guide module, a wafer positioning groove with an included angle of 45 degrees with a horizontal axis is formed in the sound guide module, a piezoelectric ceramic wafer is adhered in the wafer positioning groove through epoxy resin adhesive, high-elasticity electronic pouring sealant is filled in a gap on the back surface of the piezoelectric ceramic wafer, a throat hoop positioning groove is formed in the upper portion of the sound guide module, and an arc-shaped pipeline adhering surface is formed in the lower portion of the sound guide module.

The utility model discloses still can realize through following measure: the piezoelectric ceramic wafer adopts a single-side lead wire, and the lead wire is welded on a pin of the wiring terminal. And a junction box is fixed on the sound guide module above the electronic pouring sealant, and a signal cable enters the junction box through a waterproof joint and is pressed on the wiring terminal by a screw.

The utility model has the advantages that the polyether-ether-ketone is adopted as the sound guide module, the energy loss of ultrasonic signals is small, the sound guide module is high temperature resistant and can block heat transfer, and the outer surface electroplated layer plays a role in heat dissipation and ensures that the piezoelectric ceramic wafer works within a safe temperature; the stainless steel throat hoop connects the sound guide module electroplated layer, the stainless steel junction box and the metal pipeline to be detected into a whole, so that external electromagnetic interference signals are effectively shielded; the back of the piezoelectric ceramic wafer is filled with pouring sealant which is used as a sound absorption material to purify waveforms and has the waterproof and moistureproof effects; the device has the advantages of simple structure, convenience in installation and attractive appearance, is suitable for pipelines with various calibers, and can stably measure the flow speed and the flow of high-temperature fluid of which the temperature is not more than 260 ℃ for a long time.

Drawings

The present invention will be further explained with reference to the drawings and examples.

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a side view of the present invention.

Fig. 3 is an installation diagram of the present invention.

In the figure, 1, a metal film, 2, a sound guide module, 3, a throat hoop positioning groove, 4, a pipeline binding surface, 5, a piezoelectric ceramic wafer, 6, epoxy resin glue, 7, a wafer positioning groove, 8, electronic pouring sealant, 9, a junction box, 10, a wiring terminal, 11, a signal cable, 12, a waterproof joint, 13, a junction box upper cover, 14, a junction box screw, 15, an upper cover screw, 16, a stainless steel throat hoop, 17, a high-temperature coupling agent and 18 are used for a tested pipeline.

Detailed Description

In the figure, the utility model is provided with a sound guide module 2, the whole sound guide module 2 is used as a sound wedge, the sound guide module 2 is made of polyether ether ketone, a layer of metal film 1 is electroplated on the outer surface of the sound guide module 2, a wafer positioning groove 7 forming an included angle of 45 degrees with the horizontal axis is arranged on the sound guide module 2, a piezoelectric ceramic wafer 5 is pasted in the wafer positioning groove 7 through epoxy resin glue 6, the back gap of the piezoelectric ceramic wafer 5 is filled with high-elasticity electronic pouring sealant 8, a throat hoop positioning groove 3 is arranged above the sound guide module 2, a circular arc-shaped pipeline binding surface 4 is arranged below the sound guide module 2, the piezoelectric ceramic wafer 5 adopts a single-sided lead wire, the lead wire is welded on a pin of the wiring terminal 10, the sound guide module 2 above the electronic pouring sealant 8 is fixed with a junction box 9, and a signal cable 11 enters the junction box 9 through a waterproof connector 12 and is pressed on a wiring terminal 10 by screws.

The utility model discloses sound guide module 2 adopts polyether ether ketone panel to make through machine tooling, as ultrasonic sensor's main part, the main function is to conduct ultrasonic signal, retard heat transfer, install fixed sensor; except for the pipeline binding surface 4 and the wafer positioning groove 7, the outer surface of the sound guide module 2 is provided with the metal film 1 which can shield external electromagnetic interference signals and radiate heat conducted by a high-temperature pipeline, and after blocking and radiating, a great temperature difference is generated between the tested pipeline 18 and the piezoelectric ceramic wafer 5, so that the piezoelectric ceramic wafer 5 is not over a safe working temperature; the whole sound guide module 2 is used as a sound wedge, the sound transmission rate is extremely high, the energy loss is small when ultrasonic signals pass through, a wafer positioning groove 7 forming an included angle of 45 degrees with the horizontal axis is formed in the sound wedge, and the piezoelectric ceramic wafer 5 is adhered in the wafer positioning groove 7 through epoxy resin glue 6; the piezoelectric ceramic wafer 5 is made of lead zirconate titanate material, has a round cake shape in appearance, has a diameter of 25mm, a thickness of 2mm, a frequency of 1MHz, a Curie point of 300 ℃, and a safe working temperature within 100 ℃; the back gap of the piezoelectric ceramic wafer 5 is filled with high-elasticity electronic pouring sealant 8 which can absorb and inhibit reverse vibration waves of the piezoelectric ceramic wafer 5 as a sound absorption material to obtain a pure ultrasonic signal waveform and can play a role in water resistance and moisture resistance as a sealing material, so that the piezoelectric ceramic wafer 5 has a stable working environment, and the protection grade can reach IP 68; the piezoelectric ceramic wafer 5 adopts a single-side lead wire, the lead wire is welded to a pin of a wiring terminal 10, a signal cable 11 enters the junction box 9 through a waterproof connector 12 and is pressed on the wiring terminal 10 by a screw; the junction box 9 is made of stainless steel and is fastened on the sound guide module 2 through a junction box screw 14, so that external electromagnetic interference signals can be shielded, internal elements are protected, and wiring is facilitated; the lower part of the sound guide module 2 is provided with a circular arc-shaped pipeline binding surface 4 which ensures that the ultrasonic sensor is well contacted with the outer wall of the pipeline and is bound to the outer wall of a measured pipeline 18 through a high-temperature coupling agent 17; a throat hoop positioning groove 3 is arranged above the sound guide module 2, a stainless steel throat hoop 16 binds the sound guide module 2 and a measured pipeline 18 together through the throat hoop positioning groove 3, an ultrasonic signal enters the position of the measured pipeline 18 below the throat hoop positioning groove 3, and after the stainless steel throat hoop 16 is bound tightly, air between a sensor and the pipe wall is removed through a high-temperature coupling agent 17, so that the ultrasonic signal is smoothly transmitted to the measured pipeline 18.

The method comprises the following steps of: selecting a mounting position meeting the requirements; calculating the installation distance of the ultrasonic sensor according to the outer diameter, the wall thickness, the material and the fluid type of the measured pipeline 18; cleaning an area to be installed, removing rust and paint on the outer wall of the pipeline by using an angle grinder, and wiping off oil stains and dust by dipping clean rags with alcohol; coating sufficient couplant on the pipeline joint surface 4 and the outer wall of the measured pipeline 18; binding the sound guide module 2 and the measured pipeline 18 together by a stainless steel throat hoop 16 through a throat hoop positioning groove 3; a signal cable 11 enters the junction box 9 through a waterproof joint 12 and is pressed on the wiring terminal 10 by screws; and locking the waterproof connector 12, covering the junction box upper cover 13, and fastening an upper cover screw 15 to prevent the junction box 9 from water inflow.

Claims (2)

1. The externally-clamped high-temperature ultrasonic sensor is provided with a sound guide module and is characterized in that the sound guide module is made of polyether-ether-ketone, a metal film is electroplated on the outer surface of the sound guide module, a wafer positioning groove with an included angle of 45 degrees with a horizontal axis is formed in the sound guide module, a piezoelectric ceramic wafer is adhered in the wafer positioning groove through epoxy resin adhesive, high-elasticity electronic pouring sealant is filled in a gap on the back surface of the piezoelectric ceramic wafer, a throat hoop positioning groove is formed in the upper portion of the sound guide module, and an arc-shaped pipeline adhering surface is formed in the lower portion of the sound guide module.

2. The ultrasonic transducer of claim 1, wherein the piezoelectric ceramic chip is a single-sided lead wire, the lead wire is soldered to a pin of a terminal block, the sound guide module above the electronic potting adhesive is fixed with a terminal block, and a signal cable enters the terminal block through a waterproof joint and is pressed on the terminal block by a screw.

Images