Combined throttling device

Abstract

The utility model relates to a combined throttling device which comprises a first measuring tube, a second measuring tube arranged on one side of the first measuring tube, a first flange arranged on the first measuring tube, a second flange arranged on the second measuring tube, a pore plate arranged between the second flange and the first flange, a first pressure tapping tube arranged on the first flange and the first measuring tube, and a second pressure tapping tube arranged on the second flange and the second measuring tube. A first pressure taking pipe is arranged on the first flange, a first grading ring is arranged on the first pressure taking pipe, a second pressure taking pipe is arranged on the second flange and the second measuring pipe, a second grading ring is arranged on the second pressure taking pipe, a contraction taper pipe is arranged on the first measuring pipe, an expansion taper pipe is arranged on the second measuring pipe, and a third measuring pipe is arranged on the first grading ring and the second grading ring. And a differential pressure transmitter is arranged on the third measuring tube. According to the product, fluid contraction combing is achieved through the contraction taper pipe, vortexes are eliminated, and a flow field is homogenized; the length of the straight pipe section can be greatly reduced, the signal stability and the measurement accuracy are improved, and the market prospect is wide.

Description

TECHNICAL FIELD

[0001] The utility model relates to throttling device flowmeter field, specifically relates to a combined throttling device. BACKGROUND

[0002] Throttling device flowmeter is based on throttling principle of fluid flow, utilizes the pressure difference generated when fluid flows through throttling device to realize flow measurement. It is one of the most mature and most commonly used methods for measuring flow. Usually it is composed of throttling device that can convert measured flow into differential pressure signal and differential pressure meter and display instrument that can convert the differential pressure into corresponding flow value display. In unit combination instrument, the differential pressure signal generated by throttling device is often converted into corresponding standard signal through differential pressure transmitter for display, recording or control. There are many kinds of differential pressure flowmeters, and the differential pressure flowmeters frequently used in the market at present are: orifice flowmeter, nozzle flowmeter, V-cone flowmeter, annubar flowmeter, multi-hole balanced flowmeter and the like. The orifice flowmeter is widely used in flow measurement of gas, steam and liquid as a form of differential pressure flowmeter. It has the characteristics of simple structure, convenient maintenance, stable performance and reliable use, but needs a long straight pipe section, which seriously affects its application field.

[0003] Because fluid medium will produce vortex and eccentric flow when passing through local resistance parts such as elbow, which affects flow measurement, in the original technology, vortex and eccentric flow need to be eliminated by means of friction resistance of pipe wall and viscous force of fluid in the straight pipe section before entering the throttling device for flow measurement, but the effect is very small, only by lengthening the length of straight pipe section. For the space small hot blast furnace, gas distribution station, pump station and other sites, it is difficult to install a straight pipe section of sufficient length, and the phenomenon that the flow signal output by the throttling device fluctuates greatly so as to be unable to measure occurs. For the case of large pipe diameter conveying gas, water, steam and other fluids, vortex will also be produced due to the local resistance parts, and to eliminate these vortexes, a straight pipe section several times or ten times longer than the inner diameter size of the conveying pipeline needs to be laid, and the length of straight pipe section still cannot meet the requirement in the site. These users urgently need a flowmeter with short straight pipe section length, simple installation, stable and reliable measurement signal, high measurement accuracy. SUMMARY

[0004] In view of the defects of the prior art, the utility model provides a combined throttling device capable of reducing the length of straight pipe section and eliminating vortex carried by fluid medium, which is used for overcoming the defects in the prior art.

[0005] The utility model discloses a technical scheme that a combined throttling device is adopted, comprising a first measuring pipe, one side of the first measuring pipe is provided with a second measuring pipe, one end of the first measuring pipe close to the second measuring pipe is provided with a first flange, one end of the second measuring pipe close to the first measuring pipe is provided with a second flange, a hole plate is arranged between the second flange and the first flange, a first pressure tapping pipe is arranged on the first flange and the first measuring pipe, the number of the first pressure tapping pipe is several, a first pressure equalizing ring is arranged on the several first pressure tapping pipes, a second pressure tapping pipe is arranged on the second flange and the second measuring pipe, the number of the second pressure tapping pipe is several, a second pressure equalizing ring is arranged on the several second pressure tapping pipes, a contraction cone pipe is arranged on one end of the first measuring pipe away from the second measuring pipe, the inner diameter of the contraction cone pipe gradually increases as the contraction cone pipe gradually moves away from the first measuring pipe, an expansion cone pipe is arranged on one end of the second measuring pipe away from the first measuring pipe, the inner diameter of the expansion cone pipe gradually increases as the expansion cone pipe gradually moves away from the second measuring pipe, a third measuring pipe is arranged on the first pressure equalizing ring and the second pressure equalizing ring, and a differential pressure transmitter is arranged on the third measuring pipe.

[0006] Preferably, the central axis of the first measuring pipe and the central axis of the second measuring pipe are located on the same axis, the several first pressure tapping pipes and the several second pressure tapping pipes are uniformly distributed in the outer periphery of the central axis of the first measuring pipe in a star shape, the inlet end of the several first pressure tapping pipes is located between the top of the first measuring pipe and the bottom of the first measuring pipe, and the inlet end of the several second pressure tapping pipes is located between the top of the second measuring pipe and the bottom of the second measuring pipe.

[0007] Preferably, the top of the first pressure equalizing ring and the top of the second pressure equalizing ring are respectively provided with exhaust pipes, and the bottom of the first pressure equalizing ring and the bottom of the second pressure equalizing ring are respectively provided with blowdown pipes.

[0008] Preferably, sealing rings are arranged between the first flange and the hole plate and between the hole plate and the second flange.

[0009] Preferably, the hole plate is a standard hole plate, a tapered inlet hole plate, a circular hole plate or an eccentric hole plate.

[0010] Preferably, one end of the contraction cone pipe away from the hole plate and / or one end of the expansion cone pipe away from the hole plate is respectively provided with a length compensation mechanism, the length compensation mechanism comprises a connecting pipe arranged on one end of the contraction cone pipe away from the hole plate or one end of the expansion cone pipe away from the hole plate, a third flange arranged on the connecting pipe, an extension pipe arranged in one end of the connecting pipe away from the hole plate, a fourth flange arranged on one end of the extension pipe away from the hole plate, a fifth flange arranged on the extension pipe between the fourth flange and the connecting pipe, a second bolt arranged on the third flange and the fifth flange, and a spring arranged on the second bolt between the fourth flange and the fifth flange.

[0011] Preferably, the length compensation mechanism further comprises a sealing groove in the form of a ring formed on the inner side of the connecting pipe away from the one end of the orifice plate, a sealing filler arranged in the sealing groove, a pressing sleeve arranged on the sealing groove outside the sealing filler, a sixth flange arranged on the pressing sleeve, and a third bolt arranged on the sixth flange and the third flange.

[0012] The utility model discloses beneficial effect is: first, the utility model discloses realized that the fluid medium gradually reduces in the process of passing through the contraction cone pipe, first measuring pipe and orifice plate in turn, and flow velocity gradually increases, and the flow area is smaller when passing through orifice plate and flow velocity further increases. And the flow area becomes larger and flow velocity reduces after the fluid medium passes through orifice plate and enters second measuring pipe, and then the flow area further increases and flow velocity further reduces in the process of entering the expansion cone pipe through second measuring pipe. Just because the product has the gradual contraction of the contraction cone pipe, so can eliminate the vortex area and the deflection area of the first measuring pipe cavity on one side of orifice plate in the shorter straight pipe section, and the flow field distribution is homogenized, and it is favorable to improve the stability and accuracy of measurement. Still because the product has the expansion cone pipe, and it is favorable to the recovery of static pressure, and the pressure loss caused by measurement is reduced.

[0013] Secondly, the utility model discloses that the first flange and orifice plate and orifice plate and second flange are all respectively provided with sealing ring, and the sealing ring adopts the annular structure made of rubber or graphite material, thereby improve the sealing effect between the first flange and orifice plate and orifice plate and second flange.

[0014] Thirdly, the utility model discloses that the top of first pressure equalizing ring and the top of second pressure equalizing ring all are respectively provided with exhaust pipe, and the bottom of first pressure equalizing ring and the bottom of second pressure equalizing ring all are respectively provided with blowdown pipe, and the exhaust pipe and blowdown pipe all are divided and are provided with valve or pipe plug, thereby convenient for discharging the particulate impurities, air or cooling liquefied medium contained in first pressure equalizing ring or second pressure equalizing ring.

[0015] The utility model has the advantages of convenient installation, short required straight pipe length, stable and reliable measurement signal, high measurement accuracy, good social and economic benefits, and is a product easy to popularize and use. DRAWINGS

[0016] Fig. 1 It is the cross section structure schematic drawing of the utility model parts.

[0017] Fig. 2 It is the component composition schematic drawing of the utility model.

[0018] Fig. 3 It is the cross section schematic drawing of the utility model length compensation mechanism. PREFERRED EMBODIMENT

[0019] AsFigs. 1-3 As shown in the figure, the combined throttling device comprises a first measuring pipe 1, one side of the first measuring pipe 1 is provided with a second measuring pipe 2, one end of the first measuring pipe 1 close to the second measuring pipe 2 is provided with a first flange 3, one end of the second measuring pipe 2 close to the first measuring pipe 1 is provided with a second flange 4, a hole plate 5 is arranged between the second flange 4 and the first flange 3, a first pressure taking pipe 6 is arranged on the first flange 3 and the first measuring pipe 1, the number of the first pressure taking pipe 6 is several, a first equalizing ring 7 is arranged on the several first pressure taking pipes 6, a second pressure taking pipe 8 is arranged on the second flange 4 and the second measuring pipe 2, the number of the second pressure taking pipe 8 is several, a second equalizing ring 9 is arranged on the several second pressure taking pipes 8, a converging cone pipe 10 is arranged on one end of the first measuring pipe 1 away from the second measuring pipe 2, the inner diameter of the converging cone pipe 10 gradually increases as the converging cone pipe 10 gradually moves away from the first measuring pipe 1, an expanding cone pipe 11 is arranged on one end of the second measuring pipe 2 away from the first measuring pipe 1, the inner diameter of the expanding cone pipe 11 gradually increases as the expanding cone pipe 11 gradually moves away from the second measuring pipe 2, a third measuring pipe 12 is arranged on the first equalizing ring 7 and the second equalizing ring 9, and a differential pressure transmitter 13 is arranged on the third measuring pipe 12. According to the field requirements, the hole plate 5 adopts a standard hole plate, a tapered inlet hole plate, a circular hole plate or an eccentric hole plate.

[0020] The central axis of the first measuring pipe 1 and the central axis of the second measuring pipe 2 are located on the same axis, the several first pressure taking pipes 6 and the several second pressure taking pipes 8 are uniformly distributed on the outer periphery of the central axis of the first measuring pipe 1 in a star shape, the inlet ends of the several first pressure taking pipes 6 are located between the top of the first measuring pipe 1 and the bottom of the first measuring pipe 1, and the inlet ends of the several second pressure taking pipes 8 are located between the top of the second measuring pipe 2 and the bottom of the second measuring pipe 2, that is, avoiding the uppermost end and the lowermost end to prevent air or solid impurities from entering the first equalizing ring 7 or the second equalizing ring 9 through the first pressure taking pipe 6 or the second pressure taking pipe 8 to cause measurement signal fluctuation.

[0021] The top of the first equalizing ring 7 and the top of the second equalizing ring 9 are respectively provided with an exhaust pipe 14, and the bottom of the first equalizing ring 7 and the bottom of the second equalizing ring 9 are respectively provided with a blowdown pipe 15. Valves or pipe plugs are arranged on the exhaust pipe 14 and the blowdown pipe 15, so as to facilitate the discharge of particulate impurities, gas impurities or cooled and liquefied impurities contained in the first equalizing ring 7 or the second equalizing ring 9.

[0022] Sealing rings 16 are arranged between the first flange 3 and the hole plate 5 and between the hole plate 5 and the second flange 4, respectively, the sealing ring 16 adopts an annular structure made of rubber or graphite material, and first bolts 17 are arranged on the first flange 3 and the second flange 4; thereby improving the sealing effect between the first flange 3 and the hole plate 5 and between the hole plate 5 and the second flange 4.

[0023] As an optional embodiment of the product, for the throttle device used for the hot blast stove, since the temperature difference of the pipeline connected to the hot blast stove is large in the open state and the closed state of the hot blast stove, the pipeline will expand and contract in the temperature change process. In order to compensate the expansion and contraction amount of the pipeline, the product can be provided with a length compensation mechanism at the end of the converging cone pipe 10 away from the orifice plate 5 and / or the end of the diverging cone pipe 11 away from the orifice plate 5, respectively. The number of the length compensation mechanism is one or two. The length compensation mechanism comprises a connecting pipe 18 provided at the end of the converging cone pipe 10 away from the orifice plate 5 or the end of the diverging cone pipe 11 away from the orifice plate 5, a third flange 19 provided on the connecting pipe 18, an expansion pipe 20 provided in the end of the connecting pipe 18 away from the orifice plate 5, a fourth flange 21 provided on the end of the expansion pipe 20 away from the orifice plate 5, a fifth flange 22 provided on the expansion pipe 20 between the fourth flange 21 and the connecting pipe 18, a second bolt 23 provided on the third flange 19 and the fifth flange 22, and a spring 24 provided on the second bolt 23 between the fourth flange 21 and the fifth flange 22.

[0024] Further, the length compensation mechanism further comprises a sealing groove 25 in the form of a ring provided on the inner side of the end of the connecting pipe 18 away from the orifice plate 5, a sealing packing 26 provided in the sealing groove 25, a pressing sleeve 27 provided on the sealing groove 25 outside the sealing packing 26, a sixth flange 28 provided on the pressing sleeve 27, and a third bolt 29 provided on the sixth flange 28 and the third flange 19. Thus, the gap between the connecting pipe 18 and the expansion pipe 20 is reduced by the sealing packing 26, and the leakage of the medium during the displacement of the expansion pipe 20 is reduced. The inner diameter of the end of the expansion pipe 20 close to the orifice plate 5 gradually increases as the expansion pipe 20 gradually approaches the orifice plate 5. Thus, the turbulence caused by the difference in the inner diameter between the expansion pipe 20 and the connecting pipe 18 during the process of the fluid medium entering the connecting pipe 18 through the expansion pipe 20 is reduced. The central axis of the first measuring pipe 1, the central axis of the second measuring pipe 2, the central axis of the converging cone pipe 10, the central axis of the diverging cone pipe 11, the central axis of the connecting pipe 18, the central axis of the expansion pipe 20, and the central axis of the pressing sleeve 27 are located on the same axis. The number of the first bolts 17, the number of the first bolts 17 and the number of the second bolts 23 are several. The several first bolts 17, the several second bolts 23 and the several third bolts 29 are distributed in a star shape outside the central axis of the connecting pipe 18. The sealing packing 26 is in the form of a ring made of braided graphite or flexible graphite.

[0025] As Figs. 1-3As shown, the product is installed in the preset installation position, the upstream pipeline is connected by the fourth flange 21 in the length compensation mechanism on the contraction taper pipe 10, the downstream pipeline is connected by the fourth flange 21 in the length compensation mechanism on the expansion taper pipe 11, the second bolt 23 in the two length compensation mechanisms is adjusted, and the compression amount of the spring 24 in the length compensation mechanism is adjusted; thereby the installation work of the product is completed.

[0026] During the formal use, the upstream pipeline transports the fluid medium, which sequentially passes through the telescopic pipe 20 and the connecting pipe 18 in the length compensation mechanism on the contraction taper pipe 10 and then enters into the contraction taper pipe 10, is gradually blocked and combed and vortex is resolved by the pipe wall of the contraction taper pipe 10, and then enters into the first measuring pipe 1, is throttled by the orifice plate 5, is transported to the second measuring pipe 2, is transported to the length compensation mechanism on the contraction taper pipe 10 through the expansion taper pipe 11, is transported to the downstream pipeline through the connecting pipe 18 and the telescopic pipe 20 in the length compensation mechanism on the contraction taper pipe 10. During the period, the first static pressure in the first static pressure area on the side of the orifice plate 5 in the first measuring pipe 1 is collected by the first pressure tapping pipe 6 and is transported into the first pressure equalizing ring 7; the second static pressure in the second static pressure area on the side of the orifice plate 5 in the second measuring pipe 2 is collected by the second pressure tapping pipe 8 and is transported into the second pressure equalizing ring 9, the first static pressure is transported to the third measuring pipe 12 between the differential pressure transmitter 13 and the first pressure equalizing ring 7 by the first pressure equalizing ring 7, the second static pressure is transported to the third measuring pipe 12 between the differential pressure transmitter 13 and the second pressure equalizing ring 9 by the second pressure equalizing ring 9; the differential pressure transmitter 13 outputs the flow signal according to the difference between the received second static pressure and the first static pressure.

[0027] Through the embodiment, the fluid medium gradually reduces the flow area and gradually increases the flow velocity in the process of sequentially passing through the contraction taper pipe 10, the first measuring pipe 1 and the orifice plate 5, the flow area is smaller and the flow velocity is further increased after passing through the orifice plate 5; the flow area is larger and the flow velocity is reduced after the fluid medium passes through the orifice plate 5 and enters into the second measuring pipe 2; the flow area is further increased and the flow velocity is further reduced in the process of entering into the expansion taper pipe 11 through the second measuring pipe 2. Due to the shorter straight pipe section of the contraction taper pipe 10 of the product, the vortex area and the deflection area in the cavity of the first measuring pipe 1 on the side of the orifice plate 5 are reduced, and the flow field distribution is homogenized, which is beneficial to improve the measurement stability and accuracy. Due to the existence of the expansion taper pipe 11 of the product, the static pressure is recovered, and the pressure loss caused by the measurement is reduced.

[0028] The above-described embodiments are only preferred embodiments of the present application, and are not intended to limit the scope of the present application, so that equivalent changes or modifications made in the structure, features and principles described in the patent range of the present application should be included in the patent range of the present application.

Claims

1. A combined throttling device, characterized in that: Includes a first measuring tube (1), a second measuring tube (2) is provided on one side of the first measuring tube (1), a first flange (3) is provided at the end of the first measuring tube (1) near the second measuring tube (2), a second flange (4) is provided at the end of the second measuring tube (2) near the first measuring tube (1), an orifice plate (5) is provided between the second flange (4) and the first flange (3), a first pressure tapping tube (6) is provided on the first flange (3) and the first measuring tube (1), the number of first pressure tapping tubes (6) is several, a first equalizing ring (7) is provided on several first pressure tapping tubes (6), a second pressure tapping tube (8) is provided on the second flange (4) and the second measuring tube (2), the second pressure tapping tube (8) 8) The quantity is several, and several second pressure tapping tubes (8) are provided with second equalizing rings (9). The end of the first measuring tube (1) away from the second measuring tube (2) is provided with a shrinking cone tube (10). The inner diameter of the shrinking cone tube (10) gradually increases as the shrinking cone tube (10) gradually moves away from the first measuring tube (1). The end of the second measuring tube (2) away from the first measuring tube (1) is provided with an expanding cone tube (11). The inner diameter of the expanding cone tube (11) gradually increases as the expanding cone tube (11) gradually moves away from the second measuring tube (2). The first equalizing ring (7) and the second equalizing ring (9) are provided with a third measuring tube (12). The third measuring tube (12) is provided with a differential pressure transmitter (13).

2. The combined throttling device according to claim 1, characterized in that: The central axis of the first measuring tube (1) and the central axis of the second measuring tube (2) are located on the same axis. Several first pressure tapping tubes (6) and several second pressure tapping tubes (8) are evenly distributed in a star shape around the central axis of the first measuring tube (1) and the second measuring tube (2).

3. The combined throttling device according to claim 1, characterized in that: The top of the first equalizing ring (7) and the top of the second equalizing ring (9) are respectively provided with exhaust pipes (14), and the bottom of the first equalizing ring (7) and the bottom of the second equalizing ring (9) are respectively provided with drain pipes (15).

4. The combined throttling device according to claim 1, characterized in that: A sealing ring (16) is provided between the first flange (3) and the orifice plate (5) and between the orifice plate (5) and the second flange (4).

5. The combined throttling device according to claim 1, characterized in that: The orifice plate (5) mentioned above can be a standard orifice plate, a conical inlet orifice plate, a segmental orifice plate, or an eccentric orifice plate.

6. The combined throttling device according to claim 1, characterized in that: The contraction tapered tube (10) and / or the expansion tapered tube (11) are respectively provided with length compensation mechanisms at the ends away from the orifice plate (5). The length compensation mechanisms include a connecting tube (18) provided on the end away from the orifice plate (5) of the contraction tapered tube (10) or the end away from the orifice plate (5) of the expansion tapered tube (11), a third flange (19) provided on the connecting tube (18), a telescopic tube (20) provided inside the end away from the orifice plate (5) of the connecting tube (18), a fourth flange (21) provided on the end away from the orifice plate (5) of the telescopic tube (20), a fifth flange (22) provided on the telescopic tube (20) between the fourth flange (21) and the connecting tube (18), a second bolt (23) provided on the third flange (19) and the fifth flange (22), and a spring (24) provided on the second bolt (23) between the fourth flange (21) and the fifth flange (22).

7. The combined throttling device according to claim 6, characterized in that: The length compensation mechanism also includes an annular sealing groove (25) opened on the inner side of the end of the connecting pipe (18) away from the orifice plate (5), a sealing filler (26) provided in the sealing groove (25), a pressure sleeve (27) provided on the sealing groove (25) outside the sealing filler (26), a sixth flange (28) provided on the pressure sleeve (27), and a third bolt (29) provided on the sixth flange (28) and the third flange (19).

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