CN103925954A

CN103925954A - Venturi orifice plate

Info

Publication number: CN103925954A
Application number: CN201410086901.7A
Authority: CN
Inventors: 邵朋诚; 翟小金; 沈新建
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-05-08
Filing date: 2014-05-08
Publication date: 2014-07-16

Abstract

The invention discloses a venturi orifice plate. The venturi orifice plate is mainly characterized in that an inlet straight pipe is connected with a venturi through a shrinkage taper pipe, the venturi is connected with an expansion taper pipe with an outlet straight pipe, upper pressure holes in mutual communication are distributed on the inlet straight pipe and connected with one end of a differential pressure transmitter through an upper pressure lead pipe, a partial shrinkage orifice plate is arranged in the venturi, and lower pressure holes in mutual communication are distributed on the venturi on the lower face of the partial shrinkage orifice plate and connected with the other end of the differential pressure transmitter through a lower pressure lead pipe. Pressure loss can be reduced while larger differential pressure signals can be obtained effectively, and energy consumption is lowered as far as possible while accuracy in flow measurement is achieved. Additionally, the venturi orifice plate has the advantages of simplicity and convenience in mounting, stability and reliability in operation, high flow measurement precision, wide application range, low pressure loss, low energy consumption and the like, can be used for measuring flow of various pipe diameters and various fluids under various pressures and at various temperatures, and is especially high in flow measurement precision for large-diameter pipes and low-speed fluids.

Description

Venturi orifice plate

Technical field

The present invention relates to a kind of fluid flow rate measurement apparatus, particularly venturi orifice plate.It is applicable to the flow measurement of various fluids, is a kind of novel throttling device formula flowmeter.

Background technology

Conventionally, the flowmeter kind adopting for the flow measurement of fluid is a lot, restriction device formula flowmeter is exactly one wherein, it is numerous in variety, complete in specifications, widely used flow measurement device, mainly comprise orifice plate, nozzle, long-radius nozzle, Venturi tube, five kinds, Venturi nozzle etc., now taking orifice plate as example, it is by straight tube and embed its inner center and open round-meshed flat board and form, in the time that fluid is flowed through this orifice plate, because flow area is in the sudden contraction of circular hole place, fluid accelerates to cause static pressure to reduce herein, static pressure perisystolic static pressure and after shrinking is just causing respectively differential pressure measuring installation (differential pressure transmitter), negative pressure tappings, can obtain current signal, and then learn the size of fluid flow.Although this restriction device formula flowmeter has advantages of simple in structure, firm, reliable operation, but existing signal and be by force differential pressure value brings the pressure loss large large time, it is the shortcoming that energy consumption is large, cannot meet not only the large but also little requirement of the pressure loss of differential pressure value simultaneously, greatly restrict its application.

Summary of the invention

The object of the invention is to a kind of restriction device---venturi orifice plate of innovative design, it can overcome the deficiency of prior art, has that cost is lower, accommodation is wide, install and use easy feature.Can effectively obtain larger differential pressure signal and can make again the pressure loss less, in Measurement accuracy flow, reduce as much as possible energy consumption, thereby can reach the flow measurement precision height low object of energy consumption again.

Its solution is: through shrinking, Taper Pipe is connected with trunnion entrance straight tube, trunnion is connected again with the expansion Taper Pipe of outlet straight tube, on entrance straight tube, be distributed with the upstream pressure port being interconnected, the upstream pressure port that this is interconnected connects one end of differential pressure transmitter by upstream pressure guiding pipe, and in trunnion, be provided with local contraction orifice plate, on the trunnion of local contraction orifice plate downstream face, be distributed with the downstream pressure port being interconnected, the downstream pressure port that this is interconnected connects the other end of differential pressure transmitter by downstream pressure guiding pipe.Can conduct two static pressures of fluid from upstream and downstream pressure port, then be sent to differential pressure transmitter, by differential pressure transmitter output current signal, sequential operation as calculated, can predict the size of fluid flow.

The present invention adopts technique scheme, owing to utilizing slow contraction and the expansion of shrinking Taper Pipe and expansion Taper Pipe, to dwindle the whirlpool district of both sides, local contraction orifice plate upstream and downstream, thereby reduce the fluctuation that whirlpool district volume and intensity reduce the pressure loss, weaken differential pressure signal.On the other hand, due to fluid upstream circulating face slowly shrink and part among a small circle sudden contraction combine, in addition annular balancing slit pressure, can effectively reduce upstream shock resistance part as elbow, the impact of valve on differential pressure signal, significantly reduce the requirement to flow development length, scene in the narrow space such as gas distribution station, pumping plant or heavy-caliber pipeline flow development length deficiency also can normally be used, and the low discharge section that is conducive to heavy-caliber pipeline is measured.This flowmeter not only has installs and uses that easy, working stability is reliable, flow measurement degree of accuracy is high, accommodation is wide, the pressure loss is little, energy consumption is low, save the advantages such as the energy, and can effectively obtain larger differential pressure signal and can make again the pressure loss less, in Measurement accuracy flow, reduce as much as possible energy consumption, thereby reach the flow measurement precision height low object of energy consumption again.Can measure various calibers, various fluid as gas, liquid, the flow of steam at various pressure, temperature.Particularly the measurement of, fluid flow that flow velocity low large to bore, has higher degree of accuracy than existing measurement mechanism.

Brief description of the drawings

Fig. 1 is the main cut-open view of the structural representation of venturi orifice plate.

Embodiment

Describe the specific embodiment of the present invention in detail below in conjunction with accompanying drawing.

In Fig. 1, the present invention is installed on to internal diameter as the flow process pipeline section of 300mm is as example.The flow process pipeline section that the entrance straight tube 11 of internal diameter 300mm and axially long 300mm is 300mm with internal diameter is connected.Be distributed with along its even circumferential the upstream pressure port 1 that 4 diameters are Φ 14 in entrance straight tube 11 center, and by grading ring 10, this upstream pressure port 1 is connected, be communicated with grading ring 10 and diameter is one end that the upstream pressure guiding pipe 2 of Φ 22 connects differential pressure transmitter and indicate H.Entrance straight tube 11 by the contraction Taper Pipe 9 being communicated with it and cone angle is 30, axial length is 280mm be 150mm with internal diameter, axially the trunnion 8 of long 150mm is communicated with, this trunnion 8 is communicated with the expansion Taper Pipe 6 that with outlet straight tube and cone angle is 20, axial length is 425.3mm again.The outlet straight tube end of expansion Taper Pipe 6 and the flow process pipeline section welding that internal diameter is 300mm.Described trunnion 8 is embedded in the local contraction orifice plate 3 that a thickness of slab is 4mm, and the circular hole internal diameter that is positioned at local contraction orifice plate 3 centers is 80mm.The downstream pressure port 5 that is 10mm along 4 internal diameters of its circumference uniform distribution on the trunnion 8 of local contraction orifice plate 3 downstream faces, and by ring groove 7, these 4 downstream pressure ports 5 are communicated with, be communicated with ring groove 7 and diameter is the other end that the downstream pressure guiding pipe 4 of Φ 22 connects differential pressure transmitter and indicate L.

In the time that the fluid inflow entrance straight tube 11 in the flow process pipeline section of upstream is interior, at the original flow velocity of the interior maintenance of entrance straight tube 11, flow through subsequently and shrink Taper Pipe 9, when the circulation area of fluid reduces gradually, its flow velocity increases and hydrostatic pressure reduces simultaneously gradually, in the time that fluid is flowed through local contraction orifice plate 3 in trunnion 8, its circulation area is less, flow velocity further increases, and further reduces in the downstream face hydrostatic pressure of local contraction orifice plate 3.Can measure two static pressure signals at upstream pressure port 1 and downstream pressure port 5 places respectively, between both differential pressures and the flow value of fluid, there is a corresponding relation, according to the general Bernoulli equation of restriction device and fluid continuity equation, the fundamental equation of flow measurement can be derived by current techique, institute's measurement of discharge can be calculated accurately.

Claims

1.-kind of venturi orifice plate, it is characterized in that entrance Zhi Guan ﹙ 11 ﹚ are connected with Hou Guan ﹙ 8 ﹚ through shrinking Zhui Guan ﹙ 9 ﹚, larynx pipe ﹙ 8 ﹚ are connected again with expansion Taper Pipe ﹙ 6 ﹚ of outlet straight tube, on entrance Zhi Guan ﹙ 11 ﹚, be distributed with upstream pressure Kong ﹙ 1 ﹚ being interconnected, this upstream pressure Kong ﹙ 1 ﹚ connects one end of differential pressure transmitter by upstream impulse Guan ﹙ 2 ﹚, and in Hou Guan ﹙ 8 ﹚, be provided with local contraction Kong Ban ﹙ 3 ﹚, on Hou Guan ﹙ 8 ﹚ of local contraction Kong Ban ﹙ 3 ﹚ downstream faces, be distributed with downstream pressure Kong ﹙ 5 ﹚ that are interconnected, this downstream pressure Kong ﹙ 5 ﹚ connect the other end of differential pressure transmitter by downstream impulse Guan ﹙ 4 ﹚, from upper, downstream pressure Kong ﹙ 1 ﹚ is with ﹙ 5 ﹚ can conduct two static pressures of fluid, be sent to again differential pressure transmitter, by differential pressure transmitter output current signal, sequential operation as calculated, predict the size of fluid flow.