WO2017049782A1 - Flowmeter for laminar flow - Google Patents

Abstract

Provided is a flowmeter for laminar flow, comprising end covers (1), a main body (2), adjustment cylinder bodies (3), an upstream pressure tube (4), gaskets (5), screens (6), a differential pressure transducer (7), a laminar flow element (8) and a downstream pressure tube (9), wherein the laminar flow element (8) is composed of a hollow cylinder body (10) and a solid round bar (11), and two ends of the laminar flow element (8) are each provided with the screen (6), the gasket (5) and the adjustment cylinder body (3) in sequence.

Description

 Title of Invention: A Laminar Flowmeter

 Technical field

 The present invention relates to the field of flow measurement.

 Background technique

 [0002] A laminar flowmeter is a differential pressure flowmeter composed of a laminar flow element and a differential pressure sensor. The fluid flow is measured by measuring the differential pressure across the laminar flow element, characterized by a flow proportional to the differential pressure.

 [0003] At present, the laminar flow element used in the laminar flowmeter is generally made of a capillary tube, allowing a fluid to flow through the capillary to form a laminar flow, and then a plurality of capillary tubes are bundled to form a laminar flow element; or a corrugated plate and a flat plate are rolled, so that The fluid flows through the gap between the corrugated plate and the flat plate to form a laminar flow. The invention patent of the application No. CN201310341942.1 discloses that a laminar flow body for a gas flow meter is rolled with a stainless steel double-layer sheet, one layer. For the thickness of less than 0.1mm corrugated board, the other layer is a smooth flat plate with a thickness smaller than that of the corrugated board; or it is bundled with stainless steel capillary tube, the diameter of the capillary tube is l~3mm, and the wall thickness is 0.05~0.15mm. technical problem

 [0004] The laminar flow element produced by the prior art has high production cost, and the inner surface of the flow path of the existing laminar flow element is difficult to process, the roughness is high, the laminar flow formed is unstable, and the applicable flow range is also narrow. This results in a high price of the laminar flow meter, low measurement accuracy, and difficulty in further increasing the flow range.

 Problem solution

 Technical solution

 [0005] An object of the present invention is to provide a laminar flowmeter that solves the problem that the existing laminar flowmeter is overpriced, and the measurement accuracy and flow rate range are difficult to be further improved.

 [0006] The content of the invention is: a laminar flow meter, comprising an end cap, a main body, an adjustment cylinder, an upstream pressure tube, a gasket, a gauze, a differential pressure sensor, a laminar flow element, a downstream pressure tube, The laminar flow element is composed of a hollow cylinder and a solid round bar, and both ends of the laminar flow element are sequentially provided with a gauze, a gasket and an adjustment cylinder.

 [0007] The end cover is fixed at both ends of the main body, and the main body has two pressure guiding holes, which are respectively fixedly connected with the upstream pressure guiding tube and the downstream bow I pressure tube, and the upstream bow I pressure tube and the downstream bow I pressure tube respectively Fixed connection to both ends of the differential pressure sensor

The laminar flow element is fixed between the two pressure holes inside the main body. [0008] The area of the gauze is larger than the area of the through hole on the hollow cylinder.

 [0009] The diameter of the solid round bar is less than or equal to 3 mm, and the ratio of the length of the solid round bar to the diameter is greater than or equal to 10:1.

 [0010] The solid round bars are arranged in a row.

[0011] The arrangement of the solid round bars is a fork row.

 [0012] The solid round bar and the hollow cylinder are fixed by an interference fit between the solid round bar and the solid round bar.

 [0013] The end cap, the adjustment cylinder, the gasket, the gauze and the laminar flow element are fixed by an interference fit.

 [0014] Applying the present invention to flow measurement, fluid flows through a laminar flow flowmeter, forming a laminar flow in the laminar flow channel in the laminar flow element, and forming a differential pressure across the laminar flow element; differential pressure and fluid flow In proportion to; the differential pressure sensor measures the magnitude of the flow by measuring the magnitude of the differential pressure.

 Advantageous effects of the invention

 Beneficial effect

 [0015] The present invention creatively solves the problems encountered in prior laminar flow meters and greatly reduces the production cost of laminar flow meters. The invention adopts a solid round bar instead of a capillary to form a laminar flow channel, and the cost of the solid round bar is much lower than that of the capillary tube; the processing difficulty of the solid round bar is much lower than that of the capillary tube, and the processing precision is higher; the outer surface of the solid round bar is smooth The degree of smoothness can be higher than the inner surface of the capillary, the laminar flow formed is more stable, and the applicable flow range is wider. Compared with the existing laminar flow meter, the laminar flow flowmeter laminar flowmeter designed by the invention has lower production cost, higher measurement precision and adapts to a wider flow range.

 Brief description of the drawing

 DRAWINGS

 1 is a laminar flow meter of the present invention.

 2 is a laminar flow element of the present invention.

 3 is a further laminar flow element of the present invention.

 4 is a schematic view showing another structure of a hollow cylinder according to the present invention.

[0020] In the figure: 1, end cap, 2, main body, 3, adjustment cylinder, 4, upstream pressure pipe, 5, gasket, 6, gauze, 7, differential pressure sensor, 8, laminar flow components, 9, downstream pressure pipe, 10, hollow cylinder, 11, solid round bar, 12, laminar flow channel. BEST MODE FOR CARRYING OUT THE INVENTION

 BEST MODE FOR CARRYING OUT THE INVENTION

[0021] In order to further understand and understand the structural features and the efficacies of the present invention, the preferred embodiments and the accompanying drawings are described in detail with reference to the following description:

[0022] Embodiment 1

 [0023] The main body 2 adopts a hollow cylinder structure with a wall thickness of 25 mm and a length of 100 mm, and a square through hole having a size of 15*15 mm. Two guiding holes are arranged in the axial direction of the main body 2, and communicate with the through holes in the main body 2, respectively on both sides of the laminar flow element 8, and the diameter of the holes is 3 mm. The main body 2 can be made of stainless steel, aluminum alloy or plastic.

 [0024] The upstream bow I pressure tube 4 and the downstream bow I pressure tube 9 are respectively fixed on the two pressure guiding holes, and the fixing manner may be screw connection or welding. The upstream pressure pipe 4 and the downstream pressure pipe 9 can be made of stainless steel or the like. The upstream bow I pressure tube 4 and the downstream bow I pressure tube 9 are respectively connected to the high pressure end and the low pressure end of the differential pressure sensor 7, and are fixed by screwing or welding.

 [0025] The laminar flow element 8 is fixed in the through hole of the main body 2 between the two pressure guiding holes. The laminar flow element 8 is composed of a hollow cylinder 10 and a solid round bar 11. The hollow cylinder 10 has a wall thickness of 5 mm, a length of 30 mm, and a square through hole size of 10 * 10 mm. The material of the hollow cylinder 10 can be selected from stainless steel, aluminum alloy or ceramics.

[0026] 100 solid smooth rods 11 having a smooth surface, a diameter of 1 mm and a length of 30 mm are closely arranged in the axial direction of the through holes in the hollow cylinder 10. The arrangement of the solid round bars 11 in the hollow cylinder 10 is arranged in a row. The solid round bar U can be made of stainless steel or the like. The hollow cylinder 10 and the solid round bar 11, the solid round bars 11 are fixed to each other by an interference fit. The hollow cylinder 10 and the solid round bar 11, the gap between the solid round bars 11 constitute a laminar flow path 12.

 [0027] The gauze 6 is sized to completely cover the through holes in the hollow cylinder 10 and is slightly larger than the through holes in the hollow cylinder 10. The gauze 6 is disposed at both ends of the laminar flow element 8. The gauze 6 is used to define the axial displacement of the solid round bar in the laminar flow element 8. The material of the gauze 6 can be selected from corrosion-resistant materials such as stainless steel or plastic.

 [0028] The gasket 5 has a size of 15*15 mm and a thickness of lmm. The center of the gasket 5 has a 10*10mm square through hole. The material of the gasket 5 can be selected from corrosion-resistant materials such as stainless steel or plastic.

[0029] The adjustment cylinder 3 can adopt a hollow cylinder structure with a wall thickness of 5 mm and a length of 35 mm. The size of the hole is 10*10 mm. The adjustment cylinder 3 can also adopt a plurality of round bars having a diameter of 2 mm and a length of 35 mm, or two rectangular cylinders having a radial section of l*10 mm and a length of 35 mm. The adjustment cylinder 3 only needs to satisfy the condition that the length between the end cover 1, the adjustment cylinder 3, the spacer 5, the gauze 6, and the laminar flow element 8 in the axial direction can generate an interference fit, and the laminar flow component can be ensured. 8 is fixed at the position inside the main body 2, and ensures that the solid round bar 11 does not cause displacement in the axial direction within the hollow cylinder 10. The adjustment cylinder 3 can be made of stainless steel, aluminum alloy or ceramic.

[0030] The end cap 1 has a radial cross-sectional dimension of 40*40 mm and a length of 10 mm, and a central portion of the radial cross section of the end cap 1 has a through hole having a diameter of 15 mm and is provided with an externally threaded pipe joint of DN15. The end cap 1 can be made of stainless steel, aluminum alloy or plastic.

 [0031] The end cap 1, the adjusting cylinder 3, the spacer 5, the gauze 6, and the laminar flow element 8 are mounted on the main body 2, and the end cap 1, the main body 2, the adjusting cylinder 3, the spacer 5, and the layer are ensured. The respective axes of the flow elements 8 are on the same straight line, and the specific installation manner is as follows: The laminar flow element 8 is placed in the center of the through hole of the main body 2, so that the upstream pressure guiding tube 4 and the downstream pressure guiding tube 9 are located at the laminar flow element. 8 on both sides. On the both sides of the laminar flow element 8, a gauze 6, a spacer 5 and an adjustment cylinder 3 are sequentially placed in order. The two adjustment cylinders 3 need to be perforated at the corresponding positions of the pressure guiding holes on the main body 2, so that the upstream pressure guiding tube 4 and the downstream pressure guiding tube 9 are connected with the through holes on the adjusting cylinder 3, and the two adjusting cylinders 3 are The length is determined on a case-by-case basis and may be inconsistent. The two end caps 1 are respectively mounted at the two ends of the main body 2, and the fixed connection manner may be welding or screwing. The end cap 1, the adjusting cylinder 3, the spacer 5, the gauze 6, and the laminar flow element 8 are fixed by an interference fit, ensuring the fixing of the laminar flow element 8 in the main body 2, and ensuring that the solid round bar 11 is hollow No displacement in the axial direction occurs in the cylinder 10.

 [0032] The laminar flowmeter designed by the present invention uses 吋, the fluid flows through the end cap 1, the adjustment cylinder 3, flows through the laminar flow element 8, and forms a laminar flow in the laminar flow passage 12, and is in the layer. The differential pressure is formed at both ends of the flow element 8; the differential pressure sensor 7 senses the differential pressure across the laminar flow element 8 through the upstream bow I and the downstream bow 9. According to the principle that the differential pressure is proportional to the fluid flow in the laminar flow state, the differential pressure sensor 7 can measure the magnitude of the flow by measuring the magnitude of the differential pressure.

Embodiments of the invention

[0033] Embodiment 2

[0034] In the laminar flowmeter designed by the present invention, the discharge mode of the solid round bar 11 in the laminar flow element 8 can also be adopted. The fork rows are closely arranged, and the specific scheme refers to the practice in the first embodiment. Compared with the first embodiment, the laminar flowmeter designed by the technical scheme adopted in this embodiment has more stable laminar flow, higher measurement precision, and can adapt to a wider flow range.

 [0035] Embodiment 3

 [0036] In the laminar flowmeter designed by the present invention, the laminar flow element 8 can be fabricated by using a solid round rod 11 having a diameter of 3 mm. For the specific embodiment, the laminar flow element can be fabricated by using a solid round rod 11 having a diameter of 1 mm. . Compared with the first embodiment, the laminar flowmeter designed by using the embodiment has poor laminar flow stability, and the adapted flow range is slightly decreased, but the manufacturing cost is reduced.

 [0037] Embodiment 4

 [0038] As shown in FIG. 4, the hollow cylinder 10 and the through hole provided therein can also be formed into other shapes, as long as the placement of the solid round bar 11 can be restricted, and the specific embodiment refers to the first embodiment or the second embodiment. .

 Industrial applicability

 [0039] The laminar flowmeter designed by the present invention creatively uses a solid round bar 11 to make a laminar flow element 8, a solid round bar 1

The cost of 1 is much lower than that of the capillary tube; the processing difficulty of the solid round bar 11 is much lower than that of the capillary tube, and the processing precision is higher; the smoothness of the outer surface of the solid round bar 11 can be higher than the smoothness of the inner surface of the capillary tube, Compared with the existing laminar flowmeter, the production cost is lower, the measurement precision is higher, and the flow range is wider. The flow range that can be adapted in the prior art is 20 to 50 times, and the flow range that can be adapted by the invention reaches 20~ 200 times.

 The above exemplifications are merely illustrative of the specific embodiments of the present invention, and it should be noted that those skilled in the art can make improvements without creative labor without departing from the principles of the present invention. It is considered to fall within the scope of protection of the present invention.

Claims

Claim  [Claim 1] A laminar flow flowmeter comprising an end cap (1), a body (2), an adjustment cylinder (3), an upstream pressure pipe (4), a gasket (5), a gauze (6) a differential pressure sensor (7), a laminar flow element (8), and a downstream pressure tube (9), characterized in that: the laminar flow element (8) consists of a hollow cylinder (10) and a solid round rod (11) The two ends of the laminar flow element (8) are sequentially provided with a gauze (6), a spacer (5) and an adjustment cylinder (3).  [Claim 2] The laminar flowmeter according to claim 1, wherein: at both ends of the main body (2), an end cap (1) is fixed, and the main body (2) has two pressing holes, respectively The upstream pressure pipe (4) and the downstream pressure pipe (9) are fixedly connected, and the upstream pressure pipe (4) and the downstream pressure pipe (9) are respectively fixedly connected with the two ends of the differential pressure sensor (7), and the laminar flow element (8) Fix between the two pressure holes inside the main body (2).  [Claim 3] The laminar flowmeter according to claim 1, wherein: the area of the gauze (6) is larger than the area of the through hole in the hollow cylinder (10).  [Claim 4] The laminar flowmeter according to claim 1, wherein: the diameter of the solid round bar (11) is less than or equal to 3 mm, and the ratio of the length to the diameter of the solid round bar (11) is greater than or equal to 10: 1.  [Claim 5] The laminar flowmeter according to claim 1, wherein the solid round bars (11) are arranged in a line.  [Claim 6] The laminar flowmeter according to claim 1, wherein the solid round bars (11) are arranged in a fork row.  [Claim 7] The laminar flowmeter according to claim 1, characterized in that: the solid round bar (11) and the hollow cylinder (10), the solid round bar (11) and the solid round bar ( 11) Fixed by interference fit.  [Claim 8] The laminar flow flowmeter according to claim 1, characterized in that: the end cap (1), the adjustment cylinder (3), the gasket (5), the gauze (6) and the laminar flow The components (8) are fixed by an interference fit.