CN113252125A

CN113252125A - High measurement accuracy wet-type gas flowmeter and measurement drum slewing mechanism and measurement indicating mechanism

Info

Publication number: CN113252125A
Application number: CN202110570232.0A
Authority: CN
Inventors: 孙鸿; 姜振宇; 孙毓湖
Original assignee: YIBIN MECHATRONICS RESEARCH INSTITUTE
Current assignee: YIBIN MECHATRONICS RESEARCH INSTITUTE
Priority date: 2021-05-25
Filing date: 2021-05-25
Publication date: 2021-08-13
Anticipated expiration: 2041-05-25
Also published as: CN113252125B

Abstract

The invention discloses a high-measurement-accuracy wet gas flowmeter, a metering drum rotating mechanism and a metering indicating mechanism. The shell sealing support assembly comprises a sealing shell, an air inlet interface, an output air pipe, an air outlet interface and a support seat, a metering drum rotating mechanism comprises a metering drum, a sleeve, an inner magnetic disk, a shaft, a ball bearing and a universal ball head, and a metering indicating value indicating mechanism comprises a pointer, a core shaft, a bearing seat, a mounting bracket and an outer magnetic disk. The invention is realized by that the measured gas pushes the metering drum arranged in the shell to rotate, and then the measured value is transmitted to the metering indicating value indicating mechanism outside the shell through magnetic coupling; meanwhile, the manufacturability of the whole structure is improved, and the interchangeability of all large parts of the flowmeter is realized. The invention improves the rotation stability of the metering drum and reduces the influence of liquid level fluctuation on the metering precision.

Description

High measurement accuracy wet-type gas flowmeter and measurement drum slewing mechanism and measurement indicating mechanism

Technical Field

The invention relates to a metering instrument for measuring gas volume, in particular to a wet gas flowmeter with high measurement accuracy, a metering drum slewing mechanism and a metering indicating mechanism.

Technical Field

The wet gas flowmeter is a volumetric gas flowmeter which completely isolates the gas inlet and outlet ends of a metering drum by sealing liquid and has the characteristics of no leakage and stable metering. High accuracy wet gas flow meters are required to have a measurement spread uncertainty of 0.5%, 0.2%, often used as a standard.

The wet gas flowmeter mainly comprises a rotatable drum wheel, the interior of the rotatable drum wheel is divided into 3-5 metering gas chambers by a helical blade, the drum wheel is supported in a sealing liquid with a certain liquid level height and rotates under the action of the pressure difference of gas entering and exiting, the metering chamber leaves the liquid level and is inflated, the gas enters the liquid level and is discharged, the exhaust gas is metered, and finally, the exhaust gas metering value is obtained through mechanical or electronic recording rotation; because the gas inlet and outlet ends of the metering drum are completely isolated by the sealing liquid, the metering drum has the characteristics of no leakage and stable metering, has the measurement expansion uncertainty of 0.5 percent and 0.2 percent, and is often used as a standard device.

Because the structure design of the wet gas flowmeter in the industry is unreasonable, when the gas flow tested by the wet gas flowmeter is increased, the pressure difference between the inside and the outside of the metering chamber is increased, the liquid level difference of the sealing liquid is increased, the volume of the metering chamber is increased, the indicating value error has obvious deviation, and the indicating value error in the actual testing process is generally in a larger range of +/-1% -1.5%.

In addition, when the same flow is continuously measured for multiple times under the same environment and working conditions, the measured error is a random error, and the random error is mainly influenced by the stability of the rotation process of the metering drum wheel, so that the rotation stability of the support bearing of the metering drum wheel must be well ensured in the measurement process to improve the measurement repeatability. However, due to the requirement for lightening the flowmeter, the manufacturing of the shell welding assembly component adopts a thin-wall metal material welding forming process, and the position precision of a supporting bearing mounting hole for supporting a core shaft of the metering drum is difficult to guarantee in the welding process, so that the stability of the rotating process of the metering drum is influenced.

In the existing wet gas flowmeter, oil seals are used between a shaft for supporting a metering drum and a mounting hole for supporting a bearing for sealing treatment, but the oil seals belong to wearing parts and are easy to wear and lose efficacy, so that the hidden danger of leakage of sealing liquid exists; meanwhile, when the oil seal is worn out, the friction force is increased, which affects the rotation stability of the metering drum and causes the poor metering precision.

In summary, the accuracy of the conventional wet gas flowmeter is easily affected in the actual use process, and therefore, a highly accurate wet gas flowmeter with good repeatability is urgently needed.

Disclosure of Invention

In view of the above prior art, an object of the present invention is to provide a wet gas flowmeter with high measurement accuracy, a rotary mechanism of a metering drum, and a technical solution of a metering indicating mechanism, so as to improve measurement indication error, good repeatability, reliable sealing performance, and good structural manufacturability of the wet gas flowmeter.

The technical scheme adopted by the patent technology is mainly as follows:

a high-accuracy wet gas flowmeter is composed of a metering indicating-value indicating mechanism, a casing sealing and supporting assembly and a metering drum rotating mechanism. The shell sealing support assembly comprises a sealing shell, an air inlet interface, an output air pipe, an air outlet interface and a support seat, a metering drum rotating mechanism comprises a metering drum, a sleeve, an inner magnetic disk, a shaft, a ball bearing and a universal ball head, and a metering indicating value indicating mechanism comprises a pointer, a core shaft, a bearing seat, a mounting bracket and an outer magnetic disk. Two ends of a sealing chamber in the shell sealing and supporting component are respectively and symmetrically provided with two supporting seats, and the metering drum rotating mechanism is supported and connected in the shell sealing and supporting component through universal ball heads arranged at two ends of a shaft. The metering indicating value indicating mechanism is installed and connected to the outer portion of the shell sealing and supporting assembly through the installation support. The metering indicating value indicating mechanism and the metering drum slewing mechanism are in magnetic coupling connection with each other through two corresponding non-contact magnetic disks positioned inside and outside the sealed shell.

The wet gas flowmeter with high measurement accuracy is characterized in that: the back exhaust structure layout mode is adopted, and the back exhaust structure layout mode is composed of a flowmeter sealing shell, a metering drum, an output air pipe, an air inlet interface and an air outlet interface which are welded on the flowmeter shell. The metering drum is installed in a sealing cavity of the shell welding assembly through a bearing and becomes a part capable of freely rotating. The sealed liquid level in the cavity divides the inner cavity and the outer cavity of the metering drum into a front bin, a metering chamber and a gas collecting chamber which are directly related to gas metering, and a gas transmission channel for gas media to enter from the front end of the metering drum and to be discharged from the rear end is formed.

The wet gas flowmeter with high measurement accuracy is characterized in that: a metering drum slewing mechanism is adopted and comprises a metering drum, a sleeve, an inner magnetic disc, a shaft, a ball bearing and a universal ball head. The rotary center of the metering drum is welded with the sleeve into a whole through the connecting plate, an inner magnetic disc is installed at the front end of the sleeve, two ball bearings are installed at two ends of the inner side of the sleeve, and a shaft capable of rotating is assembled in the center of each ball bearing. The measuring drum and the shaft are connected and supported through the ball bearings to form a rotating mechanism, two universal ball heads are mounted at two ends of the shaft of the rotating mechanism and mounted in a supporting seat on the central axis of the inner wall of the shell sealing and supporting assembly, and a universal supporting structure capable of completely eliminating errors of the position degree of the supporting seat is formed in the rotating structure mode of the inner and outer double-layer composite bearings.

The wet gas flowmeter with high measurement accuracy is characterized in that: a metering indicating mechanism is adopted. Consists of a pointer, a mandrel, a bearing seat, a supporting plate and an outer magnetic disk. The shell of the shell sealing support assembly is fixedly connected with a support plate, a bearing seat with a double-row structure is installed in the center of the support plate, a pair of bearings are installed in an inner hole of the bearing seat, 1 mandrel is installed and supported in a center hole of the bearing, a magnetic disc is installed at the rear end of the mandrel, and a pointer is installed at the front end of the mandrel. The outer magnetic disk and the inner magnetic disk arranged on the metering drum in the shell sealing cabin are in magnetic coupling connection with each other on the end surface, so that synchronous external transmission of the rotary metering value of the metering drum is realized. The spindle is also provided with a rotation angle acquisition unit, and the acquisition has two modes, one mode is that the spindle is provided with a gear to transmit the rotation angle of the spindle to a mechanical counter positioned on the support plate and display the numerical value, and the other mode is that the spindle is provided with a grating encoder to convert the rotation angle of the spindle into a digital signal for output.

The patent of the invention has the following remarkable effects:

the modular structure design is characterized in that all functional components of the wet gas flowmeter are respectively integrated into three modular structures of a metering indicating value indicating mechanism, a shell welding assembly and a metering drum wheel rotating mechanism, all the modular components are simply connected through bolts, and the components are reliably connected and have strong interchangeability. Therefore, the quick state switching among series products is realized, the assembly production efficiency of the flowmeter is improved, the processing period of parts is shortened, and the daily maintenance of the flowmeter is facilitated.

The rear exhaust structure layout mode arranges the air inlet end of the metering drum which determines the indicating value error size in a front chamber outside the metering drum with relatively large sealing liquid level area, and a narrow space at the rear side inside the metering drum is taken as an air outlet end air collection chamber, so that the amplitude of the sealing liquid level in the metering chamber along with the change of the air inlet and outlet pressure difference is obviously small, and the increase of the indicating value error caused by the space change of the metering chamber due to the change of the air inlet and outlet pressure difference under different flow working conditions is reduced. Tests prove that the invention can stably control the indication error of the full flow range of the flowmeter within +/-0.5%.

The rotary mechanism of the metering drum adopts a supporting structure mode of an inner-outer double-layer composite bearing, a shaft is completely separated from the metering drum wheel, the shaft does not rotate any more and only plays a supporting role, and the shaft is arranged on an outer universal ball head. The problem of the casing because welding deformation leads to two supporting seat axiality errors of symmetrical distribution around on the casing to the bearing with measure the influence of drum running stability is solved, the measurement repeatability precision of flowmeter has been improved by a wide margin, the manufacturing degree of difficulty of the relevant spare part of flowmeter especially casing welded assembly has still been reduced simultaneously, the whole structure manufacturability has been improved.

The metering indicating mechanism transmits the metering value in a mode that the rotary metering characteristic of the metering drum in the sealed chamber of the flowmeter can be transmitted to a counter and a dial outside the flowmeter in a non-contact mode of axial end surface magnetic coupling. The structure solves the problem of the traditional flowmeter that the precision is reduced after the rotation energy loss caused by the friction force of the contact part of the oil seal lip. In addition, the inner disk and the outer disk are flexibly connected in a way that two end faces are mutually attracted in the axial direction, and the structure is simpler and more reliable compared with other radial magnetic attraction connection modes. Therefore, the full sealing of the flowmeter without leakage hidden trouble is realized, and the characteristics of the wet gas flowmeter, such as sealing property, pressure resistance, durability and the like, can be well ensured.

Drawings

FIG. 1 is a schematic diagram of a high measurement accuracy wet gas flowmeter according to an embodiment of the invention;

FIG. 2 is a schematic diagram of a rear exhaust mode structure according to an embodiment of the present invention;

FIG. 3 is a schematic view of a metering drum swing mechanism according to an embodiment of the present invention;

FIG. 4 is a schematic view of a metering indicating mechanism according to an embodiment of the present invention;

FIG. 5 is a schematic view of a metering drum cycle according to an embodiment of the present invention;

in the drawings:

the device comprises a 1 metering indicating mechanism, a 2 shell sealing and supporting component, a 3 metering drum rotating mechanism, a 4 air inlet interface, a 5 front chamber, a 6 sealing shell, a 7 metering chamber, a 8 metering drum, a 9 air collecting chamber, a 10 air outlet pipe, a 11 sealing liquid level surface, a 12 air outlet interface, a 13 sleeve, a 14 inner magnetic disc, a 15 shaft, a 16 ball bearing, a 17 universal ball head, a 18 supporting seat, a 19 pointer, a 20 core shaft, a 21 bearing, a 22 bearing seat, a 23 supporting plate, a 24 outer magnetic disc, a 25 angle quantity acquisition unit, a 26 front blade and a 27 rear blade.

Detailed description of the preferred embodiments

The patent is described in further detail below with reference to the embodiments of the figures.

The invention relates to a high-measurement-accuracy wet gas flowmeter modular structure, which is shown in figure 1: the metering drum rotating mechanism is composed of three modular components, namely a metering indicating value indicating mechanism (1), a shell sealing support assembly (2) and a metering drum rotating mechanism (3). The shell sealing and supporting assembly (2) is used for supporting the metering indicating value indicating mechanism (1) and the metering drum wheel rotating mechanism (3) to rotate in the shell sealing and supporting assembly; and a certain amount of sealing liquid is poured into the shell sealing and supporting component (2), and a plurality of sealing cavities for storing gas are formed by the sealing liquid level and the internal mechanical part. The metering drum wheel rotating mechanism (3) is used as a gas medium volume metering functional component and is installed and connected in the sealed cavity of the shell sealed supporting component (2) through a universal bearing. The metering indicating value indicating mechanism (1) is a functional component for outputting and displaying a metering value and is fixedly arranged outside a sealing cavity of the shell sealing and supporting component (2). The three modular components under the structure are connected and combined by bolts, so that a simple tool can be used for realizing the quick state switching, maintenance and replacement of series products, and the batch standardized production of the modular components can also be realized.

The structure layout of the rear exhaust mode of the wet gas flowmeter with high measurement accuracy is shown in fig. 2: the device adopts a rear exhaust structure layout mode, the mechanism layout is formed by combining two module components of a shell sealing support assembly (2) and a metering drum rotating mechanism (3) in a figure 1, and the rear exhaust structure is divided into an air inlet interface (4), a front cabin (5), a sealing shell (6), a metering chamber (7), a metering drum (8), an air collection chamber (9), an output air pipe (10), a sealing liquid level (11) and an air outlet interface (12) according to the principle. The metering drum (8) is supported by a bearing in the housing seal support assembly (2) as a freely rotatable member. The inner cavity and the outer cavity of the metering drum (8) are divided into a front chamber (5), a metering chamber (7) and a gas collecting chamber (9) by a sealing liquid level (11) in the cavity, wherein the front chamber, the metering chamber and the gas collecting chamber are directly related to gas metering and alternately circulate in the rotating process. The flowmeter with the structural layout mode works in a gas flowing state that the inlet pressure is higher than the outlet pressure, gas enters the front chamber (5) from the inlet interface (4) under the action of pressure, pressure difference is formed inside and outside side blades of the metering chamber (7) of the metering drum (8), the metering drum (8) is pushed to rotate under the action of pressure, then gas enters the metering chamber (7) in the mutual alternate circulation process of the chambers inside the metering drum (8), and is discharged to the gas collection chamber (9) after the metering chamber (7) is gradually filled with the gas, and finally the gas is discharged out of the flowmeter through the outlet gas pipe (10) and the outlet interface (12) at the rear end of the flowmeter.

The most important of the above processes are the metering process of the gas and the cyclic working process of the metering chamber (7) in the metering drum (8). As shown in fig. 5: the method comprises three processes of air intake, switching and air exhaust.

And (3) air inlet process: the gas to be measured enters the interior of the flowmeter through the gas inlet interface (4) under the action of pressure, the gas generates pressure difference on the side blades of the measuring drum (8) to force the measuring drum (8) to integrally rotate to the gas inlet process position shown in the figure 5, the front side blade (26) of the measuring drum (8) is in an open state at the moment, the rear side blade (27) of the measuring drum is in a closed state, the front chamber (5) and the measuring chamber (7) are in a communicated state, and the gas to be measured enters the measuring chamber (7) and gradually fills the measuring chamber (7) along with the rotation of the measuring drum.

And (3) switching process: the metering drum side blade continuously rotates to the switching process position shown in the figure 5 under the action of the gas pressure difference, the front side blade (26) and the rear side blade (27) of the metering drum are in a closed state at the same time, the metering chamber (7) is completely filled with gas at the moment, the volume of the gas in the metering chamber (7) which is closed by the sealing liquid level (11) at the moment is measured once, and the liquid level height at the moment determines the volume of the metered gas in the metering chamber (7).

And (3) an exhaust process: the measuring drum side blade continuously rotates to the exhaust process position shown in the figure 5 under the action of gas pressure difference, in the process, the front side blade (26) of the measuring drum (8) is always in a closed state, the rear side blade (27) of the measuring drum (8) rotates along with the measuring drum (8) to be slowly opened, the measuring chamber (7) is communicated with the gas collecting chamber (9), and the measuring drum continuously rotates to completely exhaust the measured gas from the gas output pipe (10).

According to the rear exhaust mode structure layout shown in the figure 2, the air inlet end of the metering drum (8) determining the indication error is arranged in the front bin (5) on the outer side of the metering drum (8) with relatively large sealed liquid level area, and the air collection chamber (9) of the narrow air storage space on the rear side in the metering drum (8) is used as an air outlet end, so that the relative change of the sealed liquid level height of the air inlet end before and after being pressed is small, and the indication error of the flow meter in the full flow range is reduced.

The metering drum slewing mechanism of the wet gas flowmeter with high measurement accuracy is shown in figure 3: the device consists of a measuring drum (8), a sleeve (13), an inner magnetic disc (14), a shaft (15), a ball bearing (16) and a universal ball head (17). Wherein the rotation center of the metering drum (8) is welded with the sleeve (13) into a whole through a connecting plate, the front end of the sleeve (13) is provided with an inner magnetic disc (14), two ball bearings (16) are arranged at the two ends of the inner side of the sleeve, and the center of each ball bearing (16) is provided with a shaft (15) capable of rotating. The metering drum (8) and the shaft (15) are connected and supported through the ball bearings (16) to form a rotary mechanism, two universal ball heads (17) are mounted at two ends of the rotary mechanism shaft (15), the universal ball heads (17) are mounted in a supporting seat (18) on the central axis of the inner wall of the shell sealing supporting assembly (2), and a universal supporting structure capable of completely eliminating the position error of the supporting seat (18) is formed through the rotating structure mode of the inner-layer and outer-layer composite bearings. The operation stability of the structure supporting rotary component is only influenced by the size precision of the two parts, namely the sleeve (13) and the shaft (15), and the two parts can be well guaranteed through precision machining, so that the influence on the metering precision due to the welding deformation of the flowmeter shell is completely avoided, the manufacturing difficulty of the flowmeter shell is greatly reduced, and the structural manufacturability of the whole machine is improved.

The metering indicating value indicating mechanism of the wet gas flowmeter with high measuring accuracy is shown in figure 3: the magnetic pointer comprises a pointer (19), a mandrel (20), a bearing (21), a bearing seat (22), a support plate (23) and an outer magnetic disc (24). The casing at casing sealing support assembly (2) is connected and is fixed with backup pad (23), and backup pad (23) central point puts bearing frame (22) of installing a double-row structure, and a pair of bearing (21) are installed at the hole both ends of bearing frame (22), and the installation is supported on bearing (21) centre bore has 1 dabber (20), and an outer magnetic disc (24) is installed to the rear end of dabber (20), and pointer (19) are installed to the preceding tip of axle. The outer magnetic disc (24) is in magnetic coupling connection with the inner magnetic disc (14) arranged on the metering drum (8) in the shell sealing bin body, so that real-time external transmission of the rotary metering value of the metering drum (8) is realized. The mandrel (20) is also provided with a rotation angle acquisition unit (25), and the acquisition has two modes, one mode is that the mandrel (20) is provided with a gear, the rotation angle of the mandrel (20) is transmitted to a mechanical counter on the support plate (23) and the mechanical counter displays a numerical value, and the other mode is that the mandrel (20) is provided with a grating encoder, and the rotation angle of the mandrel (20) is converted into a digital signal to be output.

Claims

1. A high measurement accuracy wet gas flowmeter characterized by: the device comprises a metering indication value indicating mechanism (1), a shell sealing supporting component (2) and a metering drum rotating mechanism (3), wherein the shell sealing supporting component (2) comprises a sealing shell (6) and a front chamber (5) positioned inside the sealing shell (6), sealing liquid is filled in the front chamber (5), two supporting seats (18) are symmetrically installed on the inner wall of the front chamber (5) respectively, universal ball heads (17) are installed at two ends of the metering drum rotating mechanism (3), the metering drum rotating mechanism (3) is supported in the front chamber (5) through the universal ball heads (17), a supporting plate (23) is further arranged on the sealing shell (6), the metering indication value indicating mechanism (1) is installed and connected outside the front chamber (5) through the supporting plate (23), an outer magnetic disk (24) is installed on the metering indication value indicating mechanism (1), and an inner magnetic disk (14) is installed on the metering drum mechanism (3), the inner magnetic disk (14) and the outer magnetic disk (24) are coupled magnetically with each other.

2. The high measurement accuracy wet gas flowmeter of claim 1, wherein the housing seal support assembly (2) has a gas outlet port (12) at a rear end thereof, and an output gas pipe (10) is mounted at the gas outlet port (12), the metering drum rotating mechanism (3) comprises a shaft (15) and a metering drum (8) rotating on the shaft (15), the metering drum (8) has a gas collection chamber (9) inside, and the output gas pipe (10) extends into the gas collection chamber (9).

3. The high measurement accuracy wet gas flowmeter of claim 1, wherein the top of the housing seal support assembly (2) is provided with an air inlet interface (4), a pressure measurement device interface and a temperature measurement device interface in communication with a front plenum (5); furthermore, a level gauge is installed at the top of the shell sealing support assembly (2), and a screw capable of adjusting the level is installed at the bottom of the shell sealing support assembly (2); furthermore, the inner magnetic disc (14) and the outer magnetic disc (24) are disc-shaped structures with mounting holes in the centers, and a plurality of magnets are uniformly distributed and embedded on the disc surfaces of the disc-shaped structures.

4. The utility model provides a measurement drum rotation mechanism, its characterized in that comprises measurement drum (8), sleeve (13), interior magnetic disc (14), axle (15), ball bearing (16), universal bulb (17), and measurement drum (8) are circular, and sleeve (13) are installed and are established on axle (15) in the rotation center department of measurement drum (8), and install ball bearing (16) to sleeve (13) both ends rotation support respectively on axle (15), and universal bulb (17) are installed respectively at the both ends of axle (15).

5. The metering drum rotating mechanism as claimed in claim 4, further comprising a metering drum rotating mechanism (3), wherein the housing sealing support assembly (2) comprises a sealing housing (6) and a front chamber (5) positioned inside the sealing housing (6), two support seats (18) are respectively and symmetrically arranged on the inner wall of the front chamber (5), and two ends of the shaft (15) are respectively supported on the two support seats (18) through universal bulbs (17); furthermore, 3-5 hollow metering chambers (7) are uniformly distributed on the inner circumference of the metering drum (8), an air collecting chamber (9) is arranged at the rear end of each metering chamber (7), and a round hole for avoiding the shaft (15) and the output air pipe (10) is formed in the center of the air collecting chamber (9); furthermore, the sleeve (13) is of a tubular hollow structure, two ends of the sleeve are respectively provided with a bearing mounting hole site, and the middle part of the sleeve is provided with a plurality of round holes for guiding sealing liquid.

6. The utility model provides a measurement indicating value indicating mechanism, a serial communication port, including casing seal supporting component (2) and backup pad (23) of installing on casing seal supporting component (2), backup pad (23) central point puts and installs a bearing frame (22), bearing frame (22) are frame construction, install a pair of bearing (21) on bearing frame (22) hole, the erection bracing has 1 dabber (20) on the hole of bearing (21), install rotation angle volume acquisition unit (25) on dabber (20), a reading structure is installed to the preceding tip of dabber (20).

7. The metrological reading indication mechanism of claim 6, characterized in that the reading structure is a pointer (19) mounted on a spindle (20).

8. The measurement indicating mechanism of claim 6 wherein the reading structure comprises a mechanical counter, the reading structure being geared with the mechanical counter.

9. The measurement indication mechanism according to claim 6, wherein the reading structure is a digital display screen of the reading structure, and the spindle (20) is provided with a grating encoder for converting a rotation angle into a digital signal and outputting the digital signal.

10. The measurement indication mechanism according to claim 6, wherein the bearing seat (22) is a double-row bearing seat, and two hole sites for mounting the bearing are arranged in the support plate (23).