CN117686040A - Laminar flow flowmeter - Google Patents
Laminar flow flowmeter Download PDFInfo
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- CN117686040A CN117686040A CN202311699749.5A CN202311699749A CN117686040A CN 117686040 A CN117686040 A CN 117686040A CN 202311699749 A CN202311699749 A CN 202311699749A CN 117686040 A CN117686040 A CN 117686040A
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- 238000011144 upstream manufacturing Methods 0.000 claims abstract description 43
- 239000012530 fluid Substances 0.000 claims abstract description 13
- 238000005192 partition Methods 0.000 claims description 10
- 238000007789 sealing Methods 0.000 claims description 10
- 230000000712 assembly Effects 0.000 claims description 8
- 238000000429 assembly Methods 0.000 claims description 8
- 125000006850 spacer group Chemical group 0.000 claims description 8
- 230000000149 penetrating effect Effects 0.000 claims description 7
- 230000008859 change Effects 0.000 description 7
- 238000009792 diffusion process Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000012545 processing Methods 0.000 description 3
- 230000006978 adaptation Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- 230000008602 contraction Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/05—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects
- G01F1/34—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by measuring pressure or differential pressure
- G01F1/36—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by measuring pressure or differential pressure the pressure or differential pressure being created by the use of flow constriction
- G01F1/40—Details of construction of the flow constriction devices
- G01F1/44—Venturi tubes
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/05—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects
- G01F1/34—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by measuring pressure or differential pressure
- G01F1/36—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by measuring pressure or differential pressure the pressure or differential pressure being created by the use of flow constriction
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F15/00—Details of, or accessories for, apparatus of groups G01F1/00 - G01F13/00 insofar as such details or appliances are not adapted to particular types of such apparatus
- G01F15/02—Compensating or correcting for variations in pressure, density or temperature
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- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Volume Flow (AREA)
Abstract
The invention discloses a laminar flow flowmeter, which comprises a venturi structure and a laminar flow element which are sequentially communicated, and further comprises a differential pressure sensor, wherein two ends of the differential pressure sensor are respectively provided with an upstream pressure collecting port and a downstream pressure collecting port, the upstream pressure collecting port is connected with the throat part of the venturi structure, and the downstream pressure collecting port is connected with the outlet of the laminar flow element; when fluid flows through the Venturi structure, negative pressure generated by the throat is used for compensating secondary linear pressure loss of the laminar flow element, so that the pressure loss and the flow of the laminar flow element are approximately in linear relation, under the restriction that the range of the differential pressure sensor is unchanged, the range of the laminar flow element can be increased only by means of pressure compensation through the Venturi structure, the size of the laminar flow element is not required to be increased, and the outline size of the laminar flow flowmeter can be reduced to a certain extent.
Description
Technical Field
The invention relates to the technical field of flow measurement, in particular to a laminar flow meter.
Background
The laminar flow flowmeter has the advantages of no movable parts, wide measuring range, accurate measurement, quick response and the like, and is widely applied to the industries of semiconductor processing, automobile electronics, food processing, chemical pharmacy, medical treatment and the like.The laminar flow meter works based on the Hagen-Poisson law and consists of a laminar flow element and a differential pressure sensor, wherein when fluid passes through the laminar flow element, the linear relation between the pressure loss and the flow of the laminar flow element is calculated, namely delta P=K 1 * Q, calculating the flow rate of the fluid. Where ΔP is the pressure loss of the laminar flow element (i.e., the difference in front and back pressure of the flow element), K 1 And Q is the flow of the laminar flow element for the linear pressure loss coefficient.
In fact, there is a large difference between the individual laminar flow elements due to processing and assembly variations, coefficient K 1 Is uncertain. Taking a laminar flow element formed by bundled capillary bundles as an example, in a specific flow range, the linear relation between the pressure loss and the flow of the laminar flow element is only established in a fully developed laminar flow stage, and the flow kinetic energy loss of fluid at an inlet and an outlet of the laminar flow element and the flow resistance loss of an inlet section of the capillary tube are approximately quadratic linear, namely the actual formula of the pressure loss and the flow of the laminar flow element is deltaP=K 1 *Q+K 2 *Q 2 Wherein ΔP is the pressure loss, K, of the laminar flow element 1 Is a linear pressure loss coefficient, Q is the flow of the laminar flow element, K 2 Is the quadratic linear pressure loss coefficient. The relationship between the pressure loss and flow of an actual laminar flow element is a superposition of linearity and quadratic linearity. When the measuring range of the differential pressure sensor is fixed, the existence of the secondary linear pressure loss can lead to the reduction of the measuring range of the flow and the deterioration of the precision of the low flow section.
To reduce the secondary linear pressure loss ratio of a laminar flow meter, the existing method is to increase the length of the capillary tube and correspondingly increase the number of the capillary tubes, but this increases the size of the flow laminar flow element, resulting in a larger profile size of the laminar flow meter. Therefore, how to reduce the secondary linear pressure loss of the laminar flow meter on the premise of reducing the outline size of the laminar flow meter is a technical problem to be solved by those skilled in the art.
Disclosure of Invention
In view of the above, an object of the present invention is to provide a laminar flow meter, which compensates the secondary linear pressure loss of a laminar flow element by using a venturi effect so that the pressure loss and the flow rate are approximately linear, and which can reduce the profile size of the laminar flow meter without increasing the size of the laminar flow element.
In order to achieve the above purpose, the invention provides a laminar flow flowmeter, which comprises a venturi structure and a laminar flow element which are sequentially communicated, and further comprises a differential pressure sensor, wherein two ends of the differential pressure sensor are respectively provided with an upstream pressure collecting port and a downstream pressure collecting port, the upstream pressure collecting port is connected with the throat part of the venturi structure, and the downstream pressure collecting port is connected with the outlet of the laminar flow element; the negative pressure created by the throat is used to compensate for the secondary linear pressure loss of the laminar flow element as the fluid flows through the venturi structure.
Preferably, the cross-sectional area of the throat is smaller than the outlet cross-sectional area of the laminar flow element.
Preferably, the device further comprises a first shell, wherein the first shell is a cylindrical shell, a first venturi hole and a first flow passage hole which are coaxially communicated are arranged in the center of the cylindrical shell, an inlet section, a constriction section, a throat and a diffusion section of the first venturi hole are sequentially and coaxially communicated to form a venturi structure, and the throat is a throat; the laminar flow element is specifically capillary bundles, the capillary bundles are concentrically distributed, and the capillary bundles are fixedly arranged in the first flow passage hole; the upstream pressure collecting port and the downstream pressure collecting port are both arranged on the side wall of the cylindrical shell and extend along the radial direction, the upstream pressure collecting port is vertically communicated with the throat, and the downstream pressure collecting port is vertically communicated with one end, far away from the first venturi hole, of the first flow passage hole.
Preferably, the device also comprises a second shell, wherein the second shell is a rectangular shell, the rectangular shell comprises an upper cover and a lower cover which are mutually buckled, and the upstream pressure collecting port and the downstream pressure collecting port are all arranged on the upper cover in a penetrating manner; a second Venturi groove and a second flow channel groove along the flowing direction are formed in the lower cover, the upstream pressure collecting port is vertically communicated with the second Venturi groove, and the downstream pressure collecting port is vertically communicated with the second flow channel groove; the second Venturi groove and the lower side surface of the upper cover are surrounded to form a Venturi structure; the laminar flow element is filled in the second flow channel, and comprises a plurality of groups of laminar flow partition plates which are arranged in a stacked manner, and a rectangular flow channel is formed between any two adjacent laminar flow partition plates; each group of laminar flow partition plates comprises a laminar flow flat plate and two laminar flow partition blocks which are fixedly arranged on the same side of the laminar flow flat plate and are respectively positioned at two ends of the laminar flow flat plate.
Preferably, the portable electronic device further comprises a third shell, wherein the third shell comprises an upper shell and a lower shell which are mutually buckled and detachably connected, the upper shell is provided with a positioning groove, and the lower shell is provided with a positioning protrusion matched with the positioning groove; the upstream pressure production port and the downstream pressure production port are all arranged on the upper shell in a penetrating way; the laminar flow element is sleeved on the positioning protrusion and comprises a plurality of groups of gasket assemblies which are arranged in a stacked mode, and an annular flow channel is formed between any two adjacent groups of gasket assemblies; each group of gasket assemblies comprises layered gaskets and spacing gaskets which are arranged in a stacked manner, and the outer diameter of each spacing gasket is smaller than that of each layered gasket; an air inlet and an air outlet are formed in the bottom of the lower shell, a third venturi groove and a third flow channel groove are formed in the lower shell, a venturi structure is formed by surrounding the third venturi groove and the lower side face of the upper shell, an inlet of the third venturi groove is connected with the air inlet, and an outlet of the third flow channel groove is connected with the air outlet; the third venturi groove is vertically communicated with the upstream pressure production port, and the third runner groove is vertically communicated with the downstream pressure production port.
Preferably, the junction of the upper and lower shells is provided with a seal.
Preferably, the device also comprises a fourth shell, wherein the fourth shell is a plate shell, the plate shell comprises a sealing cover and a bottom cover which are mutually buckled, and the upstream pressure collecting port and the downstream pressure collecting port are all arranged on the sealing cover in a penetrating manner; a fourth Venturi groove and a fourth flow channel groove which are communicated along the length direction of the plate shell are formed in the bottom cover, and the fourth Venturi groove and the lower side surface of the sealing cover enclose a Venturi structure; the laminar flow element is fixedly arranged in the fourth flow channel groove along the linear direction.
Preferably, the laminar flow element comprises a plurality of parallel laminar flow comb plates integrally fixed in the fourth flow channel groove, and a laminar flow channel is formed between any two adjacent laminar flow comb plates; or, the laminar flow element comprises a plurality of capillaries which are linearly and uniformly distributed in the fourth flow channel groove.
Preferably, the device further comprises a fifth shell, a fifth venturi cavity is formed in the fifth shell, at least one of the upper side surface and the lower side surface of the fifth venturi is provided with a trapezoid protrusion, and the trapezoid protrusion extends along the width direction of the fifth shell so that the fifth venturi cavity becomes a venturi structure; a plurality of fifth-layer flow cavities are further arranged in the fifth shell, and the thin-wall grids divide the fifth-layer flow cavities to form laminar flow elements; the fifth laminar flow cavity is communicated with the fifth Venturi cavity along the length direction of the fifth shell; the top of the fifth shell is provided with an upstream pressure collecting port and a downstream pressure collecting port, the upstream pressure collecting port is positioned at the throat part of the venturi structure, and the downstream pressure collecting port is positioned at the rear end of the laminar flow element.
Compared with the background technology, the laminar flow flowmeter provided by the invention comprises a venturi structure, a laminar flow element and a differential pressure sensor, wherein the venturi riser and the laminar flow element are sequentially communicated, the throat part of the venturi structure is provided with an upstream pressure collecting port, the outlet of the laminar flow element is provided with a downstream pressure collecting port, and two ends of the differential pressure sensor are respectively connected with the upstream pressure collecting port and the downstream pressure collecting port.
When fluid flows through the Venturi structure, negative pressure is generated at the throat part of the Venturi structure according to Venturi effect, the static pressure value collected by the upstream pressure collecting port is reduced, the secondary linear pressure loss of the laminar flow element is further compensated, the secondary linear pressure loss proportion of the laminar flow flowmeter is reduced, the pressure loss and the flow of the laminar flow element are approximately in linear relation, the range of the laminar flow element can be increased only by means of pressure compensation through the Venturi structure under the restriction of unchanged range of the differential pressure sensor, the size of the laminar flow element is not required to be increased, and the outline size of the laminar flow flowmeter can be reduced to a certain extent.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of the operation of a laminar flow meter according to an embodiment of the present invention;
FIG. 2 is a cross-sectional view of a laminar flow meter according to a first embodiment of the present invention;
FIG. 3 is a side view of FIG. 1;
FIG. 4 is a top view of a laminar flow meter according to a second embodiment of the present invention;
FIG. 5 is a cross-sectional view taken along line A-A of FIG. 4;
FIG. 6 is a cross-sectional view taken along B-B in FIG. 4;
FIG. 7 is a top view of a laminar flow meter according to a third embodiment of the present invention;
FIG. 8 is a cross-sectional view taken along line C-C of FIG. 7;
FIG. 9 is a top view of a bottom cover of a laminar flow meter according to a fourth embodiment of the present invention;
FIG. 10 is a side view of FIG. 9;
FIG. 11 is another side view of FIG. 9;
FIG. 12 is a top view of a bottom cover of a laminar flow meter according to a fifth embodiment of the present invention;
FIG. 13 is a sectional view taken along the direction D-D in FIG. 12;
fig. 14 is a sectional view taken along the direction E-E in fig. 12.
The reference numerals are as follows:
the venturi structure 1, the first venturi hole 11, the second venturi slot 12, the third venturi slot 13, the fourth venturi slot 14, the fifth venturi chamber 15, the laminar flow member 2, the capillary bundle 21, the laminar flow baffle 22, the gasket assembly 23, the layered gasket 231, the spacer 232, the laminar flow comb plate 241, the capillary 242, the fifth laminar flow chamber 25, the differential pressure sensor 3, the upstream pressure pickup port 31, the downstream pressure pickup port 32, the first housing 41, the first flow passage hole 411, the second housing 42, the upper cover 421, the lower cover 422, the second flow passage slot 423, the third housing 43, the upper housing 431, the positioning groove 4311, the lower housing 432, the positioning protrusion 4321, the air inlet 4322, the air outlet 4323, the third flow passage slot 433, the seal 434, the fourth housing 44, the bottom cover 441, the fourth flow passage slot 4411, and the fifth housing 45.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In order that those skilled in the art will better understand the present invention, the following description will be given in detail with reference to the accompanying drawings and specific embodiments.
The embodiment of the invention discloses a laminar flow flowmeter, which comprises a venturi structure 1, a laminar flow element 2 and a differential pressure sensor 3, wherein the venturi structure 1 and the laminar flow element 2 are sequentially communicated, and fluid flows into the laminar flow element 2 through the venturi structure 1, so that the flowing state of the fluid in the laminar flow element 2 is laminar. The two ends of the differential pressure sensor 3 are respectively provided with an upstream pressure collecting port 31 and a downstream pressure collecting port 32, the upstream pressure collecting port 31 is connected with the throat part of the Venturi structure 1, and the downstream pressure collecting port 32 is connected with the outlet of the laminar flow element 2. The structure and the working principle of the differential pressure sensor 3 are referred to the prior art, and will not be described in detail here.
When fluid flows through the Venturi structure 1, negative pressure is generated at the throat of the Venturi structure 1 according to Venturi effect, negative feedback is provided for the upstream pressure collecting port 31, the static pressure value collected by the upstream pressure collecting port 31 is reduced, the secondary linear pressure loss of the laminar flow element 2 is further compensated, the secondary linear pressure loss ratio of the laminar flow flowmeter is reduced, the pressure loss and the flow of the laminar flow element 2 are approximately in linear relation, furthermore, the throat sectional area of the Venturi structure 1 is reduced, the negative pressure generated by the Venturi effect is increased, the pressure difference and the flow of the laminar flow element 2 can be caused to be large along with the change of the flow, and the pressure difference of the large flow section is small along with the change of the flow.
The cross section area of the throat part is smaller than the outlet cross section area of the laminar flow element 2, so that the pressure loss and the flow of the laminar flow element 2 can be in a linear relation after the venturi structure 1 is added, and the measuring range of the laminar flow flowmeter can be improved.
In a first specific embodiment, as shown in fig. 2 and 3, the laminar flow meter further includes a first housing 41, where the first housing 41 is a cylindrical housing, and a center of the cylindrical housing is provided with a first venturi hole 11 and a first flow hole 411 that are coaxially communicated, that is, central axes of the first venturi hole 11 and the first flow hole 411 coincide. The first venturi hole 11 is a stepped hole, and an inlet section, a constriction section, a throat and a diffusion section of the first venturi hole 11 are sequentially and coaxially communicated to form a venturi structure 1, and the throat is a throat. The inlet section and the throat are cylindrical holes, and the contraction section and the diffusion section are conical holes. The first flow passage hole 411 is a cylindrical hole. The laminar flow member 2 is specifically a capillary bundle 21, the capillary bundles 21 are concentrically and circularly distributed, and the capillary bundle 21 is fixedly arranged in the first flow passage hole 411. Of course, the capillary bundle 21 may be replaced by a grid, a hexagonal honeycomb core, an array of holes, a sintered powder filter core, or the like, without being particularly limited thereto.
The upstream pressure producing port 31 and the downstream pressure producing port 32 are both arranged on the side wall of the cylindrical shell and extend along the radial direction, the upstream pressure producing port 31 is vertically communicated with the throat, and the downstream pressure producing port 32 is vertically communicated with one end of the first flow passage hole 411, which is far away from the first venturi hole 11. It should be noted that the downstream pressure recovery port 32 is located downstream of the outlet of the laminar flow member 2. The upstream pressure producing port 31 and the downstream pressure producing port 32 are linearly distributed along the axial direction of the cylindrical shell.
Compared with the first embodiment, the second embodiment is to change the structure of the housing, and the other technical solutions are the same as those of the first embodiment.
In a second embodiment, as shown in fig. 4 to 6, the laminar flow meter further includes a second housing 42, where the second housing 42 is a rectangular housing, and the rectangular housing includes an upper cover 421 and a lower cover 422 that are fastened to each other. The upstream pressure collecting port 31 and the downstream pressure collecting port 32 are both provided through the upper cover 421.
The lower cover 422 has formed therein a second venturi groove 12 and a second flow path groove 423 which communicate in the flow direction. The second venturi groove 12 and the lower side surface of the upper cover 421 are surrounded to form a venturi structure 1. The second venturi 12 is composed of an inlet section, a constriction section, a throat, and a diffuser section, the throat being the throat. Wherein, entrance section and throat all width unchangeable rectangle groove, shrink section and diffusion section are the trapezoidal groove of width gradual change all. The second flow channel groove 423 is a rectangular groove, and the width of the second flow channel groove 423 is equal to the width of the large end of the diffusion section of the second venturi groove 12. The second venturi groove 12 is vertically communicated with the upstream pressure producing port 31, and the second runner groove 423 is vertically communicated with the downstream pressure producing port 32.
The laminar flow element 2 is filled in the second flow channel 423, the width of the laminar flow element 2 is equal to the width of the second flow channel 423, and the length of the laminar flow element 2 is smaller than the length of the second flow channel 423. The laminar flow element 2 comprises a plurality of groups of laminar flow partition plates 22 which are arranged in a stacked manner, and rectangular flow channels are formed between any two adjacent laminar flow partition plates 22, so that fluid is in a laminar flow state in all the rectangular flow channels. Each group of laminar flow baffle 22 comprises a laminar flow flat plate and two laminar flow baffle blocks which are fixedly arranged on the same side of the laminar flow flat plate and are respectively positioned at two ends of the laminar flow flat plate, and the laminar flow flat plate and the two laminar flow baffle plates enclose a U-shaped groove. Of course, the structure of each set of laminar flow baffle 22 is not limited thereto.
Compared with the first embodiment, the third embodiment is to change the structure of the housing, and the other technical solutions are the same as those of the first embodiment.
In a third embodiment, as shown in fig. 7 and 8, the laminar flow meter further includes a third housing 43, and the third housing 43 is of a split design. The third casing 43 includes an upper casing 431 and a lower casing 432 that are fastened to each other and detachably connected, the upper casing 431 is provided with a positioning groove 4311, and the lower casing 432 is provided with a positioning protrusion 4321 that mates with the positioning groove 4311, so that the upper casing 431 and the lower casing 432 can be quickly installed. A connecting bolt for connecting the upper shell 431 and the lower shell 432 is arranged between the positioning groove 4311 and the positioning protrusion 4321 in a penetrating way, and a locking nut is arranged on the connecting bolt, so that detachable connection between the upper shell 431 and the lower shell 432 is realized, and the disassembly and the assembly are convenient. Of course, the connection manner between the upper case 431 and the lower case 432 is not limited thereto.
The laminar flow element 2 is sleeved on the positioning protrusion 4321, the laminar flow element 2 comprises a plurality of groups of gasket assemblies 23 which are stacked, and annular flow channels are formed between any two adjacent groups of gasket assemblies 23, so that fluid is in a laminar flow state in all the annular flow channels. Each set of shim packs 23 includes layered shims 231 and spacer shims 232 in a stacked arrangement, both layered shims 231 and spacer shims 232 being annular, the outer diameter of spacer shims 232 being smaller than the outer diameter of layered shims 231. Of course, the layered spacer 231 and the spacer 232 are not limited to the annular shape, and may be rectangular or the like, and are not particularly limited herein.
The bottom of the lower shell 432 is formed with an air inlet 4322 and an air outlet 4323, the lower shell 432 is formed with a third venturi groove 13 and a third flow channel groove 433, the lower sides of the third venturi groove 13 and the upper shell 431 are surrounded to form a venturi structure 1, an inlet of the third venturi groove 13 is connected with the air inlet 4322, and an outlet of the third flow channel groove 433 is connected with the air outlet 4323.
The upstream pressure collecting port 31 and the downstream pressure collecting port 32 are both arranged on the upper shell 431 in a penetrating manner, the upstream pressure collecting port 31 is vertically communicated with the third venturi groove 13, and the downstream pressure collecting port 32 is vertically communicated with the third flow channel groove 433.
The joint between the upper case 431 and the lower case 432 is provided with a sealing member 434 to seal the gap between the upper case 431 and the lower case 432, so that the third case 43 has good sealing properties. Specifically, the upper case 431 is provided with an annular groove, and the sealing member 434 is specifically, but not limited to, a rubber packing fitted to the annular groove.
Compared with the first embodiment, the fourth embodiment is to change the structure of the housing, and the other technical solutions are the same as those of the first embodiment.
In a fourth embodiment, as shown in fig. 9 to 11, the laminar flow meter further includes a fourth housing 44, where the fourth housing 44 is a plate-shaped housing, and the plate-shaped housing has a relatively thin thickness. The plate shell comprises a sealing cover and a bottom cover 441 which are mutually buckled, a fourth venturi groove 14 and a fourth runner groove 4411 which are communicated along the length direction of the plate shell are formed in the bottom cover 441, the fourth venturi groove 14 and the lower side surface of the sealing cover enclose a venturi structure 1, and the laminar flow element 2 is fixedly arranged in the fourth runner groove 4411 along the linear direction. The upstream pressure collecting port 31 and the downstream pressure collecting port 32 are all arranged on the sealing cover in a penetrating mode, the upstream pressure collecting port 31 is vertically communicated with the throat part of the fourth venturi groove 14, and the downstream pressure collecting port 32 is vertically communicated with the fourth runner groove 4411. In the fourth embodiment, the fourth housing 44 is preferably provided with only one layer of the laminated element 2.
The laminar flow element 2 comprises a plurality of parallel laminar flow comb plates 241, all the laminar flow comb plates 241 are integrally fixed in the fourth flow channel groove 4411, and a laminar flow channel is formed between any two adjacent laminar flow comb plates 241, so that fluid is in a laminar flow state in the laminar flow channel. Of course, the structure of the laminar flow member 2 is not limited thereto. The laminar flow member 2 includes a plurality of capillaries 242 linearly and uniformly distributed in the fourth flow channel 4411, and still achieves the object of the present invention.
Compared with the first embodiment, the fifth embodiment is to change the structure of the housing, and the other technical solutions are the same as those of the first embodiment.
In a fifth embodiment, as shown in fig. 12 to 14, the laminar flow meter further includes a fifth housing 45, a plate-shaped cavity is formed in the fifth housing 45, a fifth venturi cavity 15 is provided in the plate-shaped cavity, at least one of an upper side surface and a lower side surface of the fifth venturi cavity 15 is provided with a trapezoidal protrusion, and the trapezoidal protrusion extends along a width direction of the fifth housing 45, so that the fifth venturi cavity 15 becomes the venturi structure 1. Preferably, a trapezoidal protrusion is integrally formed at the bottom of the fifth venturi chamber 15.
A plurality of fifth laminar flow cavities 25 are further arranged in the fifth shell 45, and the thin-wall grids divide the fifth laminar flow cavities 25 to form the laminar flow element 2; the fifth laminar flow chamber 25 communicates with the fifth venturi chamber 15 along the length of the fifth housing 45; the top of the fifth housing 45 is provided with an upstream pressure collecting port 31 and a downstream pressure collecting port 32, the upstream pressure collecting port 31 is positioned at the throat part of the venturi structure 1, and the downstream pressure collecting port 32 is positioned at the rear end of the laminar flow element 2.
Of course, the structure of the laminar flow meter is not limited to the above-described five embodiments, but may be replaced by other similar structures, and is not particularly limited herein.
It should be noted that in this specification relational terms such as first and second are used solely to distinguish one entity from another entity without necessarily requiring or implying any actual such relationship or order between such entities.
The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to facilitate an understanding of the method of the present invention and its core ideas. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the invention can be made without departing from the principles of the invention and these modifications and adaptations are intended to be within the scope of the invention as defined in the following claims.
Claims (9)
1. The laminar flow flowmeter is characterized by comprising a venturi structure (1) and a laminar flow element (2) which are sequentially communicated, and further comprising a differential pressure sensor (3) with two ends provided with an upstream pressure collecting port (31) and a downstream pressure collecting port (32) respectively, wherein the upstream pressure collecting port (31) is connected with the throat part of the venturi structure (1), and the downstream pressure collecting port (32) is connected with the outlet of the laminar flow element (2); the negative pressure generated by the throat is used to compensate for the secondary linear pressure loss of the laminar flow element (2) as fluid flows through the venturi structure (1).
2. Laminar flow meter according to claim 1, characterized in that the cross-sectional area of the throat is smaller than the outlet cross-sectional area of the laminar flow element (2).
3. Laminar flow meter according to claim 1, characterized in that it further comprises a first housing (41), said first housing (41) being a cylindrical housing, the centre of which is provided with a first venturi hole (11) and a first flow channel hole (411) which are coaxially communicated, the inlet section, the constriction section, the throat and the diffuser section of said first venturi hole (11) being coaxially communicated in sequence to form said venturi structure (1), said throat being said throat; the laminar flow element (2) is specifically a capillary bundle (21), the capillary bundles (21) are concentrically distributed, and the capillary bundle (21) is fixedly arranged in the first runner hole (411); the upstream pressure collecting port (31) and the downstream pressure collecting port (32) are both arranged on the side wall of the cylindrical shell and extend along the radial direction, the upstream pressure collecting port (31) is vertically communicated with the throat, and the downstream pressure collecting port (32) is vertically communicated with one end, far away from the first venturi hole (11), of the first flow channel hole (411).
4. The laminar flow meter according to claim 1, characterized in that it further comprises a second casing (42), said second casing (42) being a rectangular casing, said rectangular casing comprising an upper cover (421) and a lower cover (422) that are mutually fastened, said upstream pressure collecting port (31) and said downstream pressure collecting port (32) being provided through said upper cover (421); a second Venturi groove (12) and a second flow channel groove (423) along the flowing direction are formed in the lower cover (422), the upstream pressure collecting port (31) is vertically communicated with the second Venturi groove (12), and the downstream pressure collecting port (32) is vertically communicated with the second flow channel groove (423); the second Venturi groove (12) and the lower side surface of the upper cover (421) are surrounded to form the Venturi structure (1); the laminar flow element (2) is filled in the second flow channel (423), the laminar flow element (2) comprises a plurality of groups of laminar flow partition plates (22) which are arranged in a stacked mode, and a rectangular flow channel is formed between any two adjacent laminar flow partition plates (22); each group of laminar flow partition plates (22) comprises a laminar flow flat plate and two laminar flow partition blocks which are fixedly arranged on the same side of the laminar flow flat plate and are respectively positioned at two ends of the laminar flow flat plate.
5. Laminar flow meter according to claim 1, characterized in that it further comprises a third casing (43), said third casing (43) comprising an upper casing (431) and a lower casing (432) which are mutually snap-fitted and detachably connected, said upper casing (431) being provided with a positioning groove (4311), said lower casing (432) being provided with a positioning protrusion (4321) cooperating with said positioning groove (4311); the upstream pressure collecting port (31) and the downstream pressure collecting port (32) are all arranged on the upper shell (431) in a penetrating way; the laminar flow element (2) is sleeved on the positioning protrusion (4321), the laminar flow element (2) comprises a plurality of groups of gasket assemblies (23) which are stacked, and an annular flow channel is formed between any two adjacent groups of gasket assemblies (23); each set of shim assemblies (23) comprises layered shims (231) and spacer shims (232) which are arranged in a stacked manner, wherein the outer diameter of the spacer shims (232) is smaller than the outer diameter of the layered shims (231); an air inlet (4322) and an air outlet (4323) are formed at the bottom of the lower shell (432), a third venturi groove (13) and a third runner groove (433) are formed in the lower shell (432), the venturi structure (1) is formed by surrounding the third venturi groove (13) and the lower side surface of the upper shell (431), an inlet of the third venturi groove (13) is connected with the air inlet (4322), and an outlet of the third runner groove (433) is connected with the air outlet (4323); the third Venturi groove (13) is vertically communicated with the upstream pressure collecting port (31), and the third runner groove (433) is vertically communicated with the downstream pressure collecting port (32).
6. Laminar flow meter according to claim 5, characterized in that the junction of the upper shell (431) and the lower shell (432) is provided with a seal (434).
7. The laminar flow meter according to claim 1, characterized in that it further comprises a fourth housing (44), said fourth housing (44) being a plate housing, said plate housing comprising a cover and a bottom cover (441) that are mutually fastened, said upstream pressure collecting port (31) and said downstream pressure collecting port (32) being provided through said cover; a fourth Venturi groove (14) and a fourth runner groove (4411) which are communicated in the length direction of the plate shell are formed in the bottom cover (441), and the fourth Venturi groove (14) and the lower side surface of the sealing cover enclose the Venturi structure (1); the laminar flow element (2) is fixedly arranged in the fourth runner groove (4411) along the linear direction.
8. The laminar flow meter according to claim 7, characterized in that the laminar flow element (2) comprises a plurality of parallel laminar flow comb plates (241) integrally fixed in the fourth flow channel groove (4411), and a laminar flow channel is formed between any two adjacent laminar flow comb plates (241); or, the laminar flow element (2) comprises a plurality of capillaries (242) which are linearly and uniformly distributed in the fourth runner groove (4411).
9. The laminar flow meter according to claim 1, characterized in that it further comprises a fifth housing (45), a fifth venturi chamber (15) being formed in the fifth housing (45), at least one of an upper side and a lower side of the fifth venturi chamber (15) being provided with a trapezoidal protrusion extending in a width direction of the fifth housing (45) to make the fifth venturi chamber (15) the venturi structure (1); a plurality of fifth-layer flow cavities (25) are further arranged in the fifth shell (45), and the thin-wall grids divide the fifth-layer flow cavities (25) to form the laminar flow element (2); the fifth layer flow chamber (25) is communicated with the fifth venturi chamber (15) along the length direction of the fifth shell (45); the top of fifth shell (45) is equipped with upstream adopts pressure mouth (31) and downstream adopts pressure mouth (32), upstream adopts pressure mouth (31) to be located venturi structure (1)'s throat, downstream adopts pressure mouth (32) to be located laminar flow element (2) rear end.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311699749.5A CN117686040A (en) | 2023-12-12 | 2023-12-12 | Laminar flow flowmeter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311699749.5A CN117686040A (en) | 2023-12-12 | 2023-12-12 | Laminar flow flowmeter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117686040A true CN117686040A (en) | 2024-03-12 |
Family
ID=90129694
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311699749.5A Pending CN117686040A (en) | 2023-12-12 | 2023-12-12 | Laminar flow flowmeter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117686040A (en) |
-
2023
- 2023-12-12 CN CN202311699749.5A patent/CN117686040A/en active Pending
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