Wavelength dispersion X-ray fluorescent tube

Abstract

A wavelength dispersion X-ray fluorescent tube is characterized in that a water spraying assembly is arranged in the center of a tube core, a high-voltage insulation socket is arranged at the lower end of the tube core, a fixed flange is arranged at the lower end of the high-voltage insulation socket, a top cover is arranged at the lower end of the fixed flange, and the top cover is connected with the fixed flange through a screw; a cooling water pipe is arranged on the upper portion of the right side of the top cover, a cooling water connector is arranged on the lower portion of the right side of the top cover, the cooling water connector is communicated with the cooling water pipe, and a high-pressure flange cover is arranged on the lower portion of the center of the top cover. The target surface is vertical to the longitudinal axis of the tube, and the anode and the cathode are respectively provided with a set of cooling system to achieve the purpose of cooling, so that the temperatures of the cathode part and the anode part are always kept within a certain temperature limit when the X-ray tube works.

Description

Technical Field

[0001] The invention relates to an X-ray tube, in particular to a wavelength dispersion X-ray fluorescent tube. Background Art

[0002] Wavelength dispersion X-ray fluorescent tubes are mainly used in ROHS testing, density analysis, military industry, aerospace, geological exploration and other scientific research fields and industrial sectors that require X-ray sources, such as metallurgy, geology, chemical industry, biology, environment, semiconductor electronics industry, etc.

[0003] Wavelength dispersion X-ray fluorescence tubes have a wide range of applications and a broad market prospect. At present, the tubes used in fluorescence analyzers sold by domestic sellers are all produced abroad, with a long delivery cycle and high prices. The demand for fluorescent tubes in the domestic and foreign markets is huge, but native domestic fluorescent tubes have not yet appeared.

[0004] 1. The shell of foreign fluorescent tubes adopts glass structure, which we call glass tubes, and has the following disadvantages: 1. The electrical insulation of glass is low. In high-voltage devices such as X-ray tubes, electrons will scatter and gather on the glass shell. If the roundness of the glass shell is uneven, the distribution of electrons on the shell will also be uneven, which will further reduce the insulation strength of the shell and make the X-ray tube more prone to sparking or breakdown.

[0005] 2. The glass has a low melting point. During high-temperature processing, it is difficult to ensure the overall roundness of the glass tube and the precise dimensions of the assembly with other components. At the same time, the lack of high temperature in the exhaust will lead to incomplete exhaust in the tube, low vacuum and short filament life.

[0006] 3. Glass has low mechanical strength. It is easy to break under mechanical vibration and impact, and the probability of X-ray tube damage is high.

[0007] 2. Foreign fluorescent tubes use high-voltage insulating oil for insulation. The high-voltage insulating oil is filled in the tube container and wrapped around the outside of the tube shell. It is not only large in size and weight, but also has the following disadvantages: 1. Aging of insulating oil. Insulating oil will gradually age under long-term high temperature and high voltage conditions, causing its insulation performance to deteriorate and increasing the risk of breakdown. Aged insulating oil may also produce acidic substances, further corroding the internal structure.

[0008] 2. Difficult maintenance and replacement. The insulating oil needs to be replaced and processed regularly, which increases the complexity of maintenance. Replacing the insulating oil requires professional equipment and technicians, which increases operating costs and affects normal use and production efficiency.

[0009] 3. Thermal management issues. The fluidity and heat dissipation capacity of the insulating oil may be uneven, resulting in uneven heat distribution inside the X-ray tube, affecting the stability and life of the equipment. Especially in high-power applications, the heat generated by the X-ray tube may not be effectively removed, causing certain parts of the X-ray tube to overheat, increasing the risk of failure and equipment loss.

[0010] 4. Oil leakage and pollution risk. The insulating oil system has the risk of oil leakage, especially when the sealing is poor or aging. This not only affects the normal operation of the equipment, but also may pollute the environment.

[0011] 5. Electrical insulation problems. Insulating oil may form uneven electric field distribution under the action of electric field, resulting in local weak insulation area and increasing the risk of breakdown. Insulating oil is prone to form bubbles in high temperature and high voltage environment. The insulation performance of bubbles is low and may cause local breakdown. Summary of the invention

[0012] In view of the above problems, the present invention provides a wavelength dispersion X-ray fluorescent tube with a metal ceramic structure, which has stable electrical properties, can extend the life of the filament, has high mechanical strength, and adopts a high-voltage insulating socket structure. The solid insulating material has more stable insulation performance under high temperature and high voltage environments, is not easy to age, does not need to be regularly replaced and treated like insulating oil, improves the overall availability of the equipment, reduces maintenance costs, and will not leak like insulating oil, has a lower risk of environmental pollution, and is more environmentally friendly.

[0013] The technical measures taken to solve the above technical problems are: A wavelength dispersive X-ray fluorescent tube, characterized in that the X-ray tube consists of a tube core 1, a water spray fitting 2, a high-voltage insulating socket 3, a shell 4, a cooling water pipe 5, a fixing flange 6, a top cover 7, a cooling water joint 8, and a high-voltage flange cover 9. The tube core 1 is arranged on the X-ray tube, a water spray fitting 2 is arranged at the central part of the tube core 1, a high-voltage insulating socket 3 is arranged at the lower end of the tube core 1, a fixing flange 6 is arranged at the lower end of the high-voltage insulating socket 3, a top cover 7 is arranged at the lower end of the fixing flange 6, the top cover 7 is connected to the fixing flange 6 by screws to fix the position of the high-voltage insulating socket 3, a shell 4 is arranged outside the entire X-ray tube, the lower end of the shell 4 is circumferentially connected to the fixing flange 6 by screws, the upper end of the shell 4 is circumferentially connected to the X-ray tube tube core 1, a cooling water pipe 5 is arranged on the upper right side of the top cover 7, and cooling is conducted along the shell 4 to the upper part of the tube core 1, a cooling water joint 8 is arranged on the lower right side of the top cover 7, the cooling water joint 8 is communicated with the cooling water pipe 5, and a high-voltage flange cover 9 is arranged at the central lower part of the top cover 7; The tube core 1 is composed of a ceramic flange 11, a stainless steel tube shell 12, an anode body 13, a tube shell transition ring 14, a cathode body 15, an anode target 16, a cathode head 17, a molybdenum rod 18, a filament 19, a cathode sleeve 110, a cathode body transition piece 111, and a window fitting 112. The ceramic flange 11 is arranged at the lower end of the tube core 1, the inner side of the ceramic flange 11 is connected to the lower end of the anode body 13, and the stainless steel tube shell 12 is welded on the outer side. The anode target 16 is installed at the uppermost end of the anode body 13, and the stainless steel tube shell 12 is welded on the outer side. The upper end is argon-arc welded with the tube shell transition ring 14, the inner side of the tube shell transition ring 14 is brazed with the cathode body 15, the inner side of the cathode body 15 is equipped with a cathode head 17, a molybdenum rod 18 is riveted on the cathode head 17, the filament 19 is spot-welded on the molybdenum rod 18, a cathode sleeve 110 is installed on the inner side of the cathode head 17, a cathode body transition piece 111 is installed between the cathode body 15 and the cathode head 17, and is used to connect the window fitting 112, and the cathode body transition piece 111 and the window fitting 112 are circumferentially welded by argon arc welding; The high-voltage insulating socket 3 is made of solid insulating material, and a lower water inlet hole 31 and a lower water outlet hole 32 are respectively provided on both sides of the lower section of the high-voltage insulating socket 3, and two holes are respectively provided on the top of the high-voltage insulating socket 3, namely an upper water inlet hole 33 and an upper water outlet hole 34, wherein the lower water inlet hole 31 and the upper water inlet hole 33 are connected inside the high-voltage insulating socket 3, and the lower water outlet hole 32 and the upper water outlet hole 34 are connected inside the high-voltage insulating socket 3. Cooling water enters from the lower water inlet hole 31 and flows to the upper water inlet hole 33, and then flows into the water spraying assembly 2 to cool the anode target 16, and then flows into the upper water outlet hole 34, and flows out from the lower water outlet hole 32 through the internal channel of the high-voltage insulating socket 3 to complete the cooling process.

[0014] Positive effects of the present invention: The ceramic flange 11 and the stainless steel tube shell 12 in the wavelength dispersion X-ray fluorescent tube of the present invention form a metal ceramic structure to replace the imported glass tube shell. The volume and weight of the entire tube are greatly reduced by using the metal ceramic structure. It also has the following advantages: 1. Stable electrical performance. The shell of the metal ceramic tube is grounded, which effectively dissipates heat and removes the charge accumulated on the tube wall. Compared with glass blowing, the processing of the metal shell is more controllable, with higher dimensional accuracy and uniform charge scattering distribution. In addition, ceramics have high electrical insulation and a dielectric constant that is twice that of glass. The electrical performance stability of metal ceramic X-ray tubes is much higher than that of glass X-ray tubes.

[0015] 2. Extend the life of the filament. Compared with glass tubes, metal-ceramic X-ray tubes can be exhausted at a higher temperature during the manufacturing process, which can be used to create a higher degree of vacuum. Releasing high voltage in a high vacuum helps reduce positive ions, which will bombard the cathode filament. The higher the vacuum, the less bombardment the filament receives. At the same time, in an oxygen-free environment, the effect of heating and oxidation of the filament will be minimized. Combining the two, the filament life of the metal-ceramic X-ray tube is significantly longer than that of the glass tube.

[0016] 3. High mechanical strength. When the temperature of the X-ray tube rises sharply due to operation, the volume change rate that ceramics can withstand is higher than that of glass. In addition, ceramics are harder than glass, with tensile and bending strengths 2 to 3 times that of glass, and compressive strength 30 times that of glass. Therefore, in X-ray applications that require mobility or portability and are prone to frequent vibrations, the high mechanical strength of metal ceramic X-ray tubes makes them more durable than glass tubes at the physical structure level.

[0017] The high-voltage insulating socket 3 in the wavelength dispersion X-ray fluorescent tube of the present invention adopts solid insulating material to replace the high-voltage insulating oil part in the original imported fluorescent tube, which has the following advantages: 1. Good stability: Solid insulating materials have more stable insulation properties under high temperature and high voltage environments and are not prone to aging.

[0018] 2. Simple maintenance: Solid insulation materials do not need to be replaced and handled regularly like insulating oil, reducing maintenance needs and downtime, improving the overall availability of equipment and reducing maintenance costs.

[0019] 3. Environmental protection: Solid insulating materials will not leak like insulating oil, and the risk of environmental pollution is lower.

[0020] The anode of the wavelength dispersive X-ray fluorescent tube works under positive high voltage, and the anode and cathode each have a cooling system. The filament of the cathode is set in a ring anode shape, and the target surface is perpendicular to the longitudinal axis of the tube. This design emits rays parallel to the longitudinal axis of the tube, which greatly reduces the distance between the detected object and the transmission ray window. The wavelength dispersive X-ray fluorescent tube in the present invention is a transmission-type microfocus X-ray tube, which can emit strong, broad-spectrum X-rays in a short time and can perform high-speed analysis. Unlike other analytical determinations, fluorescence analysis is a non-destructive physical analysis method. During the determination and analysis, it will not cause changes in the chemical state of the analyzed substance, and there will be no sample scattering phenomenon. The same sample can be measured and analyzed repeatedly, and the results are reproducible. At the same time, elements belonging to the same group in chemical properties can also be analyzed. With multiple advantages, the existence of wavelength dispersive X-ray fluorescent tubes is bound to play an irreplaceable role in promoting industrial development and scientific progress. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a cross-sectional view of the overall internal structure of the present invention; Figure 2 It is a cross-sectional view of the internal structure of the tube core of the present invention; Figure 3 It is a cross-sectional view of the internal structure of the high-voltage insulating socket of the present invention. DETAILED DESCRIPTION

[0022] The present invention is described in detail below with reference to the accompanying drawings. A wavelength dispersion X-ray fluorescent tube, the overall internal structure of which is shown in cross-section as follows Figure 1 As shown, the X-ray tube consists of a tube core 1, a water spray fitting 2, a high-voltage insulating socket 3, a shell 4, a cooling water pipe 5, a fixed flange 6, a top cover 7, a cooling water joint 8, and a high-voltage flange cover 9. The tube core 1 is arranged on the X-ray tube, and a water spray fitting 2 is installed at the central part of the tube core 1. The lower end of the tube core 1 is equipped with a high-voltage insulating socket 3, the lower end of the high-voltage insulating socket 3 is equipped with a fixed flange 6, and the lower end of the fixed flange 6 is equipped with a top cover 7. The top cover 7 is connected to the fixed flange 6 by screws to fix the position of the high-voltage insulating socket 3. The outer shell 4 is installed outside the entire X-ray tube, the lower end of the shell 4 is circumferentially connected to the fixed flange 6 by screws, and the upper end is circumferentially connected to the tube core 1 of the X-ray tube, a cooling water pipe 5 is installed on the upper right side of the top cover 7, and is cooled along the shell 4 to the upper part of the tube core 1, a cooling water joint 8 is installed on the lower right side of the top cover 7, and the cooling water joint 8 is communicated with the cooling water pipe 5, and a high-voltage flange cover 9 is installed at the center lower part of the top cover 7.

[0023] Figure 2 The figure is a cross-sectional view of the internal structure of the tube core of the present invention. The tube core 1 is composed of a ceramic flange 11, a stainless steel tube shell 12, an anode body 13, a tube shell transition ring 14, a cathode body 15, an anode target 16, a cathode head 17, a molybdenum rod 18, a filament 19, a cathode sleeve 110, a cathode body transition piece 111, and a window assembly 112. The ceramic flange 11 is arranged at the lower end of the tube core 1, the inner side of the ceramic flange 11 is connected to the lower end of the anode body 13, and the stainless steel tube shell 12 is welded to the outer side. The ceramic flange 11 and the stainless steel tube shell 12 form a metal ceramic structure to replace the imported glass tube shell. The metal ceramic structure greatly reduces the volume and weight of the entire tube, and has the advantages of stable electrical performance, extended filament life, high mechanical strength, etc. The uppermost end of the anode body 13 is provided with an anode target 16, the upper end of the stainless steel tube shell 12 is argon arc welded with the tube shell transition ring 14, the inner side of the tube shell transition ring 14 is brazed with the cathode body 15, the inner side of the cathode body 15 is provided with a cathode head 17, a molybdenum rod 18 is riveted on the cathode head 17, a filament 19 is spot welded on the molybdenum rod 18, a cathode sleeve 110 is provided on the inner side of the cathode head 17, a cathode body transition piece 111 is provided between the cathode body 15 and the cathode head 17, and is used to connect a window fitting 112, and the cathode body transition piece 111 and the window fitting 112 are circumferentially welded by argon arc welding.

[0024] The high-voltage insulating socket 3 is made of solid insulating material, and a lower water inlet hole 31 and a lower water outlet hole 32 are respectively provided on both sides of the lower section of the high-voltage insulating socket 3, and two holes are respectively provided on the top of the high-voltage insulating socket 3, namely an upper water inlet hole 33 and an upper water outlet hole 34, wherein the lower water inlet hole 31 and the upper water inlet hole 33 are connected inside the high-voltage insulating socket 3, and the lower water outlet hole 32 and the upper water outlet hole 34 are connected inside the high-voltage insulating socket 3. The cooling water enters from the lower water inlet hole 31 and flows to the upper water inlet hole 33, and then flows into the water spraying assembly 2 to cool the anode target 16, and then flows into the upper water outlet hole 34, and flows out from the lower water outlet hole 32 through the internal channel of the high-voltage insulating socket 3 to complete the cooling process. The high-voltage insulating socket adopts solid insulating material, which has more stable insulation performance under high temperature and high voltage environment, is not easy to age, does not need to be replaced and treated regularly like insulating oil, improves the overall availability of the equipment, reduces maintenance costs, and will not leak like insulating oil, has a lower risk of environmental pollution, and is more environmentally friendly.

[0025] When the present invention is working, the electrons generated by the cathode filament due to heating are accelerated by high voltage and then fly to the anode target surface, and then the movement is suddenly stopped. A small part of the kinetic energy of the electrons, about 1%, is converted into radiation energy and emitted in the form of X-rays. The rays are irradiated onto the sample to be tested through the beryllium window. The target surface material of this ray tube can be rhodium (Rh), copper (Cu), molybdenum (Mo), tungsten (W), chromium (Cr), platinum (Pt), etc. according to different needs. The remaining 99% of the kinetic energy of the electrons is converted into thermal energy, so a forced cooling structure is required to prevent the target from melting. When the cooling system of the present invention is working, a part of the cooling water enters from the first cooling water joint 8, flows into the upper part of the tube core 1 through the cooling water pipe 5, flows around the outside of the cathode body 17 for one week, and then flows out from the second cooling water joint 8 to ensure that the cathode part of the ray tube is controlled within a certain temperature. Another part of the cooling water enters from the third cooling water joint 8, passes through the top cover 7, flows through the fixed flange 6 and enters the high-voltage insulating socket 3, flows through the internal spiral channel of the high-voltage insulating socket 3, and then passes through the water spraying fitting 5 installed in the central part of the high-voltage insulating socket 3 and is sprayed into the bottom of the anode target 18, so as to achieve the purpose of cooling, so that the temperature of the anode part of the X-ray tube is always kept within a certain temperature limit when it is working.

Claims

1. A wavelength dispersive X-ray fluorescent tube characterized by: The X-ray tube comprises a tube core (1), a water spray fitting (2), a high-voltage insulating socket (3), a housing (4), a cooling water pipe (5), a fixing flange (6), a top cover (7), a cooling water joint (8), and a high-voltage flange cover (9). The tube core (1) is arranged on the X-ray tube, a water spray fitting (2) is arranged at the center of the tube core (1), a high-voltage insulating socket (3) is arranged at the lower end of the tube core (1), a fixing flange (6) is arranged at the lower end of the high-voltage insulating socket (3), a top cover (7) is arranged at the lower end of the fixing flange (6), and the top cover (7) is connected to the fixing flange (6) by screws. The flange (6) is connected to fix the position of the high-voltage insulating socket (3), a shell (4) is installed outside the entire ray tube, the lower end of the shell (4) is circumferentially connected to the fixing flange (6) by screws, and the upper end is circumferentially connected to the tube core (1) of the ray tube, a cooling water pipe (5) is installed on the upper right side of the top cover (7), and is connected to the upper part of the tube core (1) along the shell (4) for cooling, a cooling water joint (8) is installed on the lower right side of the top cover (7), and the cooling water joint (8) is connected to the cooling water pipe (5), and a high-pressure flange cover (9) is installed at the center lower part of the top cover (7); The tube core (1) is composed of a ceramic flange (11), an inner tube (12), an anode body (13), a tube transition ring (14), a cathode body (15), an anode target (16), a cathode head (17), a molybdenum rod (18), a filament (19), a cathode sleeve (110), a cathode body transition piece (111), and a window assembly (112). The ceramic flange (11) is arranged at the lower end of the tube core (1), the ceramic flange (11) is connected to the lower end of the anode body (13), and a stainless steel tube shell (12) is welded on the outer side. The anode target (16) is installed at the uppermost end of the anode body (13). The stainless steel tube shell (12) is welded on the outer side. ) is argon arc welded to the tube shell transition ring (14), the inner side of the tube shell transition ring (14) is brazed to the cathode body (15), a cathode head (17) is mounted on the inner side of the cathode body (15), a molybdenum rod (18) is riveted on the cathode head (17), a filament (19) is spot welded to the molybdenum rod (18), a cathode sleeve (110) is mounted on the inner side of the cathode head (17), a cathode body transition piece (111) is mounted between the cathode body (15) and the cathode head (17) to connect the window assembly (112), and the cathode body transition piece (111) and the window assembly (112) are circumferentially welded by argon arc welding; The high-voltage insulating socket (3) is made of solid insulating material. A lower water inlet hole (31) and a lower water outlet hole (32) are respectively provided on both sides of the lower section of the high-voltage insulating socket (3). Two holes, namely an upper water inlet hole (33) and an upper water outlet hole (34), are respectively provided on the top of the high-voltage insulating socket (3). The lower water inlet hole (31) and the upper water inlet hole (33) are connected inside the high-voltage insulating socket (3), and the lower water outlet hole (32) and the upper water outlet hole (34) are connected inside the high-voltage insulating socket (3). Cooling water enters from the lower water inlet hole (31) and flows to the upper water inlet hole (33), thereby flowing into the water spray assembly (2) to cool the anode target (16). The cooling water then flows into the upper water outlet hole (34), passes through the internal channel of the high-voltage insulating socket (3), and flows out from the lower water outlet hole (32), thereby completing the cooling process.

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