Rod type ultrasonic liquid level meter for measuring MO source steel cylinder

Abstract

The invention relates to the field of liquid level meters, in particular to a rod type ultrasonic liquid level meter for measuring an MO source steel cylinder. The device comprises an inner pipe, an ultrasonic transducer, a host, and a VCR welded pipe, an outer pipe, a probe seat and a bottom cap which are sequentially connected from top to bottom, the top of the probe seat is provided with an inner hole, the upper part is provided with a liquid inlet communicated with the inner hole, and the bottom is provided with a mounting groove for mounting an ultrasonic transducer; the pipe diameter of the inner pipe is smaller than that of the outer pipe, the inner pipe is arranged in the outer pipe, the bottom end of the inner pipe is connected to the inner hole of the probe seat and communicated with the liquid inlet, and the top end of the inner pipe penetrates through the peripheral surface of the outer pipe; and the ultrasonic transducer is electrically connected with the host. The liquid level of the MO source liquid can be measured in a non-contact mode through the ultrasonic technology.

Description

Technical Field

[0001] The invention relates to the field of liquid level meters, in particular to a rod-type ultrasonic liquid level meter for measuring MO source cylinders. Background Art

[0002] MO source, i.e., a high-purity metal organic compound, is a supporting source material for the modern compound semiconductor industry. Since the first use of MOCVD (Metal-organic Chemical Vapor Deposition) to prepare GaAs single crystal thin films, this technology has developed rapidly and has now become an important method for producing ultra-thin multi-layer heterostructures and large-scale uniform materials, and for preparing compound semiconductor devices such as GaAs and GaN, microwave devices, optical devices, and optoelectronic devices. The core raw material required for the MOCVD process is a metal organic source (abbreviated as MO source). MO sources are currently divided into three categories: metal oxide MO source, metal nitride MO source, and metal film MO source. The MO source needs to be stored in a MO cylinder supply device with high cleanliness and high packaging effect and at the same time protected by inert gas, with reference to the technology disclosed in Chinese Patent Publication No. CN109852948A.

[0003] Currently, improvements to MO source storage cylinders are mainly reflected in size, sealing, connection, and cleaning, but there is a lack of technology for non-contact measurement of the liquid level of the MO source liquid in the MO source bottle. Summary of the Invention

[0004] The purpose of the present invention is to address the problems existing in the background technology and propose a rod-type ultrasonic level meter for measuring MO source cylinders, which can use ultrasonic technology to perform non-contact measurement of the liquid level of MO source liquid.

[0005] The technical solution of the present invention is a rod-type ultrasonic liquid level meter for measuring MO source cylinders, comprising an inner tube, an ultrasonic transducer, a main unit, and a VCR welded pipe, an outer tube, a probe base and a bottom cap connected in sequence from top to bottom; the probe base has an inner hole at the top, a liquid inlet connected to the inner hole at the upper portion, and a mounting groove for mounting the ultrasonic transducer at the bottom; the inner tube has a diameter smaller than that of the outer tube, the inner tube is arranged inside the outer tube, the bottom end of the inner tube is connected to the inner hole of the probe base, the bottom end of the inner tube is connected to the liquid inlet, and the top end of the inner tube passes through the outer circumference of the outer tube; the ultrasonic transducer is electrically connected to the main unit.

[0006] Preferably, the VCR welded pipe, the outer pipe, the probe seat and the bottom cap are welded together in sequence, and the bottom end of the inner pipe is welded together with the probe seat.

[0007] Preferably, the upper portion of the probe base has a lead hole that is communicated with the mounting groove and passes upward through the top of the probe base, and the lead hole is located on one side of the inner hole.

[0008] Preferably, the inner tube includes a vertically distributed vertical tube portion and a horizontal tube portion horizontally connected to the top of the vertical tube portion. The horizontal tube portion passes through the outer circumference of the outer tube. The outer end of the horizontal tube portion is an exhaust port, and the ultrasonic transducer faces upward toward the vertical tube portion.

[0009] Preferably, a potting area is formed between the inner tube and the outer tube, and a wire is connected between the ultrasonic transducer and the host, passing through the lead hole, the potting area and the VCR welded pipe from bottom to top, and the potting area is potted with epoxy glue.

[0010] Preferably, the ultrasonic transducer transmits ultrasonic waves with a frequency of 500kHz-3MHz. When the ultrasonic waves propagate in the liquid in the inner tube, they encounter the interface at the top of the liquid and are reflected. The reflection time is T, the speed of sound propagation in the liquid is V, and the height of the liquid level in the inner tube is H, then H=VT / 2.

[0011] Compared with the prior art, the present invention has the following beneficial technical effects:

[0012] This liquid level meter utilizes the principles of ultrasonic emission and acoustic theory as its theoretical foundation to perform non-contact measurement of the liquid level within an MO source bottle. To measure the liquid level, the structure below the VCR welded tube in the meter is inserted into the MO source bottle. Liquid enters through the liquid inlet and rises from the bottom of the inner tube, where the liquid level is located within the vertical section of the inner tube. The ultrasonic transducer emits ultrasonic waves, which are reflected when they reach the liquid surface. The liquid level is calculated based on relevant principles and theories and displayed on the host computer, achieving ultrasonic non-contact measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Schematic diagram of the structure of an embodiment of the present invention;

[0014] Figure 2 for Figure 1 Structural cross-sectional view;

[0015] Figure 3 for Figure 2 A magnified view of the structure at point A;

[0016] Figure 4 Schematic diagram of the structure of the inner tube;

[0017] Figure 5 This is a structural diagram of the probe base.

[0018] Figure numerals: 1, VCR welded pipe; 2, outer tube; 3, probe seat; 301, inner hole; 302, mounting groove; 303, lead hole; 304, liquid inlet; 4, bottom cap; 5, inner tube; 6, main unit. DETAILED DESCRIPTION

[0019] like Figure 1-Figure 5As shown, the present embodiment proposes a rod-type ultrasonic level gauge for measuring MO source cylinders, comprising an inner tube 5, an ultrasonic transducer, a main unit 6, and, from top to bottom, a VCR welded pipe 1, an outer tube 2, a probe holder 3, and a bottom cap 4 welded together in sequence. The ultrasonic transducer is electrically connected to the main unit 6, and the liquid level measurement results can be displayed on the display screen of the main unit 6. The bottom end of the inner tube 5 is welded to the probe holder 3. The VCR welded pipe 1, outer tube 2, probe holder 3, and bottom cap 4 are all circular in structure. The VCR welded pipe 1 has a 1 / 2 or 3 / 4 joint. The lower diameter of the VCR welded pipe 1 is larger than that of the outer tube 2. When the outer tube 2 is inserted into the MO source cylinder, the VCR welded pipe 1 can serve as a positioning device at the top, and the structure below the VCR welded pipe 1 extends downward into the MO source cylinder. The position of the VCR welded pipe 1 is determined, the dimensions of the MO source cylinder are known, and the lengths of the remaining structures are known, and the position is determined accordingly. Specifically, the level gauge is inserted to the bottom of the MO source cylinder. The bottom edge of the outer tube 2 is aligned with the top edge of the probe base 3 , and the bottom edge of the probe base 3 is aligned with the top edge of the bottom cap 4 , and they are welded by laser welding.

[0020] like Figure 3 As shown, the probe base 3 has an inner hole 301 at the top, a liquid inlet 304 connected to the inner hole 301 at the top, and a mounting groove 302 for mounting an ultrasonic transducer at the bottom. The ultrasonic transducer can be mounted in the mounting groove 302 by gluing, such as using AB glue. After the ultrasonic transducer is installed in place, a bottom cap 4 is welded to the bottom of the probe base 3. The ultrasonic transducer is encapsulated inside. The ultrasonic transducer emits ultrasonic waves and distinguishes them by the difference in reflected echo energy when there is liquid and when there is no liquid. The upper part of the probe base 3 has a lead hole 303 connected to the mounting groove 302 and extending upward through the top of the probe base 3. The lead hole 303 is located on one side of the inner hole 301. The ultrasonic transducer is connected to a wire that can pass upward through the lead hole 303.

[0021] The inner tube 5 has a smaller diameter than the outer tube 2. Both are 316L EP-grade stainless steel (clean tubes), with bright, seamless inner and outer surfaces. The outer tube 2 has a diameter of 1 / 2 inch, 3 / 4 inch, etc., while the inner tube 5 has a diameter of 1 / 4 inch, 3 / 8 inch, etc. The inner tube 5 is positioned within the outer tube 2. Its bottom end is connected to the inner hole 301 of the probe holder 3 and is connected to the liquid inlet 304, specifically by welding. Liquid enters through the liquid inlet 304 and flows upward into the inner tube 5. The top end of the inner tube 5 penetrates the outer circumference of the outer tube 2, and this penetration can also be welded.

[0022] like Figure 2 and Figure 4 As shown, specifically, the inner tube 5 includes a vertically distributed vertical tube portion and a horizontal tube portion horizontally connected to the top of the vertical tube portion. The horizontal tube portion passes through the outer circumference of the outer tube 2. The outer end of the horizontal tube portion is an exhaust port, and the ultrasonic transducer faces upward toward the vertical tube portion.

[0023] like Figure 2 As shown, a potting area is formed between the inner tube 5 and the outer tube 2, and the potting area is connected to the lead hole 303. The wire passes through the lead hole 303, the potting area and the VCR welded tube 1 from bottom to top, and is led out to the outside and connected to the host 6. Then, epoxy glue is poured into the potting area, and the upper and lower ends are sealed to protect the wire.

[0024] The ultrasonic transducer has a size of 5-10 mm and transmits ultrasonic waves with a frequency of 500 kHz-3 MHz. When the ultrasonic wave propagates in the liquid in the inner tube 5, it encounters the interface at the top of the liquid and is reflected. The reflection time is T, that is, the time from the emission of the ultrasonic wave to the reflection of the ultrasonic wave is T. The speed of sound in the liquid is V, and the height of the liquid level in the inner tube 5 is H, then H=VT / 2.

[0025] This embodiment uses ultrasonic non-contact measurement technology that does not come into contact with the liquid being measured. It utilizes the ultrasonic emission principle and acoustic theory as the theoretical basis for the liquid level meter to perform non-contact measurement of the liquid level in the MO source bottle. When measuring the liquid level, the structure below the VCR welded pipe 1 in this liquid level meter is inserted into the MO source bottle. Liquid enters through the liquid inlet 304 and upwards into the inner tube 5 from the bottom end. Gas squeezed out by the liquid is discharged from the exhaust port at the outer end of the horizontal tube portion, and the liquid level is located in the vertical tube portion of the inner tube 5. The ultrasonic transducer emits ultrasonic waves, which are reflected when they propagate to the liquid surface. The liquid level is calculated based on relevant principles and theories and displayed on the host 6, achieving ultrasonic non-contact measurement.

[0026] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A rod-type ultrasonic level meter for measuring MO source cylinders, characterized in that: It comprises an inner tube (5), an ultrasonic transducer, a main unit (6), and a VCR welded tube (1), an outer tube (2), a probe base (3) and a bottom cap (4) connected in sequence from top to bottom; The probe base (3) has an inner hole (301) at the top, a liquid inlet (304) in communication with the inner hole (301) at the upper portion, and a mounting groove (302) for mounting an ultrasonic transducer at the bottom; The diameter of the inner tube (5) is smaller than that of the outer tube (2). The inner tube (5) is arranged inside the outer tube (2). The bottom end of the inner tube (5) is connected to the inner hole (301) of the probe seat (3). The bottom end of the inner tube (5) is communicated with the liquid inlet (304). The top end of the inner tube (5) passes through the outer peripheral surface of the outer tube (2). The ultrasonic transducer is electrically connected to the host (6).

2. A rod-type ultrasonic level meter for measuring MO source cylinders according to claim 1, characterized in that: The VCR welded pipe (1), the outer pipe (2), the probe seat (3) and the bottom cap (4) are welded and connected in sequence, and the bottom end of the inner pipe (5) is welded and connected to the probe seat (3).

3. The rod-type ultrasonic level meter for measuring MO source cylinder according to claim 1, characterized in that: The upper portion of the probe seat (3) has a lead hole (303) that is in communication with the mounting groove (302) and passes upward through the top of the probe seat (3), and the lead hole (303) is located on one side of the inner hole (301).

4. A rod-type ultrasonic level meter for measuring MO source cylinders according to claim 3, characterized in that: The inner tube (5) comprises a vertically distributed vertical tube portion and a horizontal tube portion horizontally connected to the top end of the vertical tube portion. The horizontal tube portion penetrates the outer peripheral surface of the outer tube (2). The outer end of the horizontal tube portion is an exhaust port, and the ultrasonic transducer faces upward toward the vertical tube portion.

5. A rod-type ultrasonic level meter for measuring MO source cylinders according to claim 4, characterized in that: A potting area is formed between the inner tube (5) and the outer tube (2), and a wire is connected between the ultrasonic transducer and the host (6) and passes through the lead hole (303), the potting area and the VCR welded pipe (1) in sequence from bottom to top, and the potting area is potted with epoxy glue.

6. A rod-type ultrasonic level meter for measuring MO source cylinders according to claim 4, characterized in that: The ultrasonic transducer emits ultrasonic waves with a frequency of 500kHz-3MHz. When the ultrasonic waves propagate in the liquid in the inner tube (5), they are reflected after encountering the interface at the top of the liquid. The reflection time is T, the propagation speed of sound in the liquid is V, and the height of the liquid level in the inner tube (5) is H, then H=VT / 2.

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