CN216309087U

CN216309087U - Back-to-back pitot tube flow transmitter

Info

Publication number: CN216309087U
Application number: CN202121469239.5U
Authority: CN
Inventors: 不公告发明人
Original assignee: Ningbo Jingfeng Measurement And Control Technology Co ltd
Current assignee: Ningbo Jingfeng Measurement And Control Technology Co ltd
Priority date: 2021-06-30
Filing date: 2021-06-30
Publication date: 2022-04-15
Anticipated expiration: 2031-06-30

Abstract

The utility model provides a back-to-back pitot tube flow transmitter, comprising: the explosion-proof junction box comprises an explosion-proof junction box body and an upper circuit board and a lower circuit board which are arranged in the explosion-proof junction box body, and a micro differential pressure sensor, a pressure sensor and an amplifying circuit board are arranged on the lower layer. The adoption of a back-to-back pitot tube is beneficial to increasing the collected signals so as to improve the measurement precision, the adoption of a micro differential pressure sensor and a pressure sensor, the pressure sensor collects the internal pressure of the pipeline, the signals are taken from one of two channels of the micro differential pressure sensor, and a temperature sensor arranged below an installation joint collects the internal temperature signals of the pipeline, so that the simultaneous sampling and collection of the three signals are realized, and the functions are more; the pitot tube flow transmitter belongs to the field of back-to-back pitot type flow transmitters; the backrest tube type measuring principle is more advanced than the Pitot tube type measuring principle; compared with the existing three-valve group, the three-valve group formed by the miniature ball valves has the advantages of smaller volume, lighter weight, lower cost and more reasonable overall structure.

Description

Back-to-back pitot tube flow transmitter

Technical Field

The utility model relates to the technical field of metering instruments, in particular to a back-to-back pitot tube flow transmitter integrating temperature, pressure and flow.

Background

At present, when monitoring the flow rate of a gas pipeline, a diffusing pipe and the like, various flow meters are often installed by cutting off a pipeline, welding a flange at the front and rear cut-off parts, and fastening a meter detection main body by using a plurality of bolts during installation. The flow meter adopting the installation mode is inconvenient to install and maintain. In addition, pitot tube (pitot tube) probe type flow meters such as a split type combined parameter meter 2020100552394 and a split type flow monitor 2020100552534 appear on the market at present, although convenience is brought to installation, the pitot tube probe type flow meter has the defects of large volume, high cost, unadjustable installation direction of a fixed joint and unsuitability for installation of small pipelines.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problems and provides a back-to-back pitot tube flow transmitter which has the advantages of high precision, small volume, light weight, multiple parameters, low cost, compact structure, convenience in installation, cable connection, probe replacement and the like.

The technical scheme adopted by the utility model is as follows:

a back-to-back pitot tube flow transmitter comprising: the explosion-proof junction box comprises an explosion-proof junction box body, an upper circuit board and a lower circuit board which are arranged in the explosion-proof junction box body, wherein the lower circuit board is provided with a micro differential pressure sensor, a pressure sensor and an amplifying circuit board, the upper circuit board is provided with a voltage stabilizing circuit board and a wiring terminal, and an electric wire explosion-proof leading-out wire hole is formed in the rear side of the explosion-proof junction box; the micro differential pressure sensor, the pressure sensor and the amplifying circuit board form a sensor combined amplifying circuit board; the signal input ports of the micro differential pressure sensor and the pressure sensor are respectively inserted into three sealing holes on the top end face of an upper pressing block of a combined three-valve set fixed at the lower end of an explosion-proof box body, a front ball valve and a rear ball valve are respectively clamped between the upper pressing block and the lower pressing block with sealing rings and are pressed and fixed by 4 screws, a balance ball valve component is arranged in the upper pressing block and is integrated with the upper pressing block, left and right vertical channels penetrate through holes in the upper pressing block and the lower pressing block from bottom to top, two ends of a balance valve in the upper pressing block are communicated with the left and right channels to form the combined three-valve set together with the left and right ball valves, the lower end faces of the left and right through holes in the lower pressing block are screwed with two inner wire holes of a stainless steel back-leaning pitot tube, the small-diameter part at the lower part of the lower pressing block is arranged in a sealing ring groove and a screw fastening groove, an outer sleeve is provided with a stainless steel mounting head with an outer wire, and the inner channel passes through the upper end faces of the lower pressing block and the left and right pressing block, two ends of the balance valve are communicated with the left channel and the right channel to form a combined three-valve set.

The temperature sensor lead-out wire passes through the upper pressing block threading hole and the outer thread sealing pressing sleeve threading hole of the lower pressing block to the upper part and the circuit board, and the temperature sensor is fixed at the lower end of the lower pressing block.

The utility model has the beneficial effects that:

1. according to the utility model, by arranging the back-to-back type pitot tube probe, a sampling joint of an original pressure gauge of a measured pipeline can be directly utilized, or an installation joint is additionally arranged on the measured pipeline by pre-forming an installation hole, so that the installation of a pipe cutting welding flange is not needed, and the directions of installing and adjusting the pitot tube are simple; through the integral design of the explosion-proof junction box, the micro differential pressure sensor, the amplifying circuit board, the combined three-valve set and the pitot type back rest pipe probe part, the length of the pitot pipe probe can be conveniently replaced according to the caliber of a pipeline, and convenience is brought to use and maintenance; adopt and lean against formula pitot tube and be favorable to increasing the collection signal so that improve measurement accuracy, adopt little differential pressure sensor and pressure sensor, and pressure sensor gathers pipeline internal pressure, and the signal is got from one of them passageway of two passageways of little differential pressure sensor, and the temperature sensor that the erection joint below set up gathers pipeline internal temperature signal, and the sampling collection when realizing three kinds of signals is more.

2. In this patent, the pitot tube flow transmitter belongs to and leans against the pipe pitot formula flow transmitter category.

3. The back-rest tube measurement principle is more advanced than the pitot tube measurement principle.

4. Compared with the existing three-valve group, the three-valve group formed by the miniature ball valves has the advantages of smaller volume, lighter weight, lower cost and more reasonable overall structure.

Drawings

FIGS. 1-2 are external views of a back-to-back Pitot flow transmitter in accordance with one embodiment of the present invention;

FIGS. 3-4 are cross-sectional views of a back-to-back Pitot tube flow transmitter in accordance with one embodiment of the present invention;

FIGS. 5-6 are schematic views of the exploded structure of FIGS. 3-4 in combination with a sensor and a counter balance valve;

reference numerals:

an explosion-proof junction box 1, a combined three-valve group 2, a balanced ball valve handle 3, a front ball valve handle 4, a rear ball valve handle 5, a mounting joint 6, a temperature sensor 7, a back-to-back pitot tube forward probe 8, a back-to-back pitot tube reverse probe 9, an upper pressing block 10, a front ball valve 11, a rear ball valve 12, an outgoing line sealing screw 13, a pressing screw 14, a lower pressing block 15, a wiring terminal and voltage-stabilized source circuit board 16, a operational amplifier circuit board 17, a micro differential pressure sensor 18, a pressure sensor 19, a front channel 20, a rear channel 21, a balanced ball valve 22, a ball valve sealing gasket 23, a first channel 25, a second channel 26, a ball pad 27, a pressing screw sleeve 28, a ball center 29, an outgoing line 30, a through hole 31 and a fastening screw 32; the pressure sensor comprises a sealing ring 33, a sealing ring 101 of an upper pressing block and explosion-proof junction box, a temperature outgoing line protective tube 102, a protective tube opening sealing nut 103, a protective tube opening 104, an upper pressing block and explosion-proof junction box fastening screw hole 105, a micro differential pressure sensor sealing ring 181, a micro differential pressure sensor mounting hole 182, a pressure sensor sealing ring 191 and a pressure sensor mounting hole 192.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1-2, the back-to-back pitot tube flow transmitter of the embodiment of the utility model comprises a circuit board 16 provided with a wiring terminal and a stabilized voltage power supply and an operational amplifier circuit board 17 provided with a micro differential pressure sensor 18 and a pressure sensor 19, wherein the circuit board 16 is arranged in an explosion-proof junction box 1;

the upper part of the combined three-valve group 2 is fixed with the explosion-proof junction box 1, the lower part is sleeved with an installation joint 6 with a fixing screw 32 on the side surface, a front ball valve 11 and a rear ball valve 12 in the middle are respectively clamped between an upper pressing block 10 and a lower pressing block 15 which are provided with a sealing ring 23, and are pressed and fixed 32 by 4 screws, as shown in figure 2, a balance ball valve 22, a ball center 29, a ball pad 27 and a pressing screw sleeve 28 are arranged in the upper pressing block 10, the balance ball valve 22 is communicated with a front channel 20 and a rear channel 21, and a sealing ring groove and a fixing screw groove are arranged at the lower part of the lower pressing block 15 sleeved with the installation joint 6;

the back-to-back type pitot tube forward probe 8 and the back-to-back type pitot tube reverse probe 9 are respectively fixed in end face screw holes of the first channel 25 and the second channel 26 below the lower pressing block 15. An outgoing line 30 of the temperature sensor 7 penetrates through a threading hole of the lower pressing block 15 and is tightly pressed by an outgoing line sealing screw 13;

as shown in fig. 3 to 4, the explosion-proof junction box 1 includes a voltage stabilizing circuit board 16, a micro differential pressure sensor 18, a pressure sensor 19 and an amplifying circuit board 17 which are arranged in the explosion-proof junction box 1, and the combined three-valve set 2 is clamped by an upper pressing block 10 and a lower pressing block 15 between a front ball valve 11 and a rear ball valve 12 and is fastened by a compression screw 14;

the lower pressing block 15 is provided with a through hole 31 and a sealing screw 13, the temperature sensor is fixed at the lower end of the lower pressing block (15), the outgoing line 30 penetrates through the through hole of the lower pressing block (15) to the upper pressing block (10) of the outgoing line protection tube (102) to the upper circuit board, and the sealing nut (103) is used for isolating and fixing the tube protection opening (104) and the through hole of the upper pressing block (10);

as shown in fig. 5 to 6, in an embodiment of the present invention, the explosion-proof junction box 1 is an explosion-proof aluminum housing, and as shown in fig. 1, an explosion-proof wire outlet hole is formed at the rear side of the explosion-proof junction box 1, so that the safety of the back-to-back pitot tube flow transmitter can be improved when the back-to-back pitot tube flow transmitter is applied to various gas pipelines, diffusing pipes and other scenes of a gas pressure regulating station.

As shown in fig. 3 to 4, in an embodiment of the present invention, a small stainless steel high-pressure ball valve is used for the front ball valve 11, the rear ball valve 12 and the balance valve 22 of the combined three-valve group 2, and a stainless steel sheath is arranged outside the combined three-valve group 2;

in one embodiment of the utility model, a sealing ring is arranged at the joint of the lower part of the explosion-proof junction box 1 and the upper pressing block 10, and the upper part and the lower part of the explosion-proof junction box 1 are fixed through screws 18.

As shown in fig. 5 to 6, in an embodiment of the present invention, a valve seat with 3 channels is disposed in an upper pressing block 10 of a combined three-valve set 2, wherein 2 channels are differential pressure signal input channels of a front ball valve 11 and a rear ball valve 12, an input channel is disposed below the combined three-valve set 2, an output channel is disposed above the combined three-valve set, a balance ball valve 22 is disposed across a middle section of the 2 output channels, and another is a threading through hole of an outgoing line 30 of a temperature sensor 7.

As shown in fig. 2, a micro differential pressure sensor 18 and a pressure sensor 19 in the explosion-proof junction box 1 are respectively sleeved with a sealing ring and inserted into a jack at the top end of an upper pressing block 10, and are fixed and pressed by 4 screws of a circuit board;

the back-to-back pitot tube forward probe 8 and the lower detection hole of the back-to-back pitot tube reverse probe 9 which are parallelly and vertically arranged on the lower end surface of the lower pressing block 15 of the combined three-valve group 2 are opposite to each other;

in one embodiment of the present invention, the back-to-back pitot forward probe 8 and the back-to-back pitot reverse probe 9 are both stainless steel.

When the device is used, after a field pipeline of the back-to-back pitot tube flow transmitter is installed, the depth and the angle can be adjusted, then a fastening screw of an installation joint is screwed, an electric wire explosion-proof leading-out wire hole is screwed on the rear side of an explosion-proof junction box 1, a 5-core glue wire penetrates through the explosion-proof joint to be connected with a wiring terminal, a 16V-24V direct-current stabilized voltage power supply, a differential pressure signal, a pressure signal and a temperature signal output end are respectively connected, a cover of the explosion-proof junction box 1 is covered, the other end of the 5-core glue wire is connected with a nearby display instrument or a measurement and control room display instrument, a balance valve of a combined three-valve set is required to be opened before the back-to-back pitot tube flow transmitter is electrified, a front ball valve 11 and a rear ball 12 are closed, so that a micro differential pressure sensor 18 and a pressure sensor 19 in the back-to-back pitot tube flow transmitter are in a zero pressure state, and zero point detection and maintenance are facilitated.

The embodiment of the utility model has three independent signal outputs of micro-differential pressure, pressure and temperature, can realize remote monitoring and data storage functions by adopting an RS485 communication protocol, and is suitable for measurement, control, configuration and management of a field nearby display instrument or a remote display instrument.

The embodiment of the utility model carries out micro differential pressure detection on the flow of the gas pipeline by using a back-to-back pitot tube measuring principle, can acquire the central fluid flow velocity (total pressure-static pressure is equal to dynamic pressure) of the pipeline, and then multiplies the central fluid flow velocity by the sectional area of the pipeline to be detected, according to the Bernoulli equation: the flow rate is the central flow velocity multiplied by the sectional area, the flow rate is automatically converted into the working condition flow rate of the fluid, PV/T is a constant C, and the working condition flow rate is automatically converted into the standard condition flow rate by a formula P1V1/T1 or P2V 2/T2.

According to the split type combined parameter instrument, the back-to-back pitot tube probe is arranged, so that a sampling joint of an original pressure gauge of a pipeline to be measured can be directly utilized, or an installation joint is additionally arranged on the pipeline to be measured by pre-forming an installation hole, therefore, the installation of a pipe cutting welding flange is not needed, the installation is simple, the anti-explosion junction box internally provided with the micro differential pressure sensor and the pressure sensor, the combined three-valve set and the back-to-back pitot tube probe form an integrated design, the on-site installation can be conveniently carried out, the anti-explosion junction box can be replaced, or other parts are modified, and the installation and maintenance are simple and convenient; the pressure sensor shares one channel of the micro differential pressure sensor, the sampling of the pressure signal is also considered while the sampling of the differential pressure signal is obtained, meanwhile, the smoothness of a signal line of the temperature sensor is considered by arranging the temperature sensor, the simultaneous acquisition of three signals can be realized, and the functions are multiple.

1. In the patent, a pitot tube flow transmitter is within the category of a back to back tube pitot type flow transmitter.

2. The back-rest tube measurement principle is more advanced than the pitot tube measurement principle.

3. Compared with the existing three-valve group, the three-valve group formed by the miniature ball valves has the advantages of smaller volume, lighter weight, lower cost and more reasonable overall structure.

In the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the utility model, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A back-to-back pitot tube flow transmitter, comprising:

the explosion-proof junction box (1), the pressure sensor (19), the micro differential pressure sensor (18), the temperature signal line, the signal conversion circuit and the wiring terminal are arranged in the explosion-proof junction box (1), and the wire explosion-proof leading-out wire hole is arranged at the rear side;

a left ball valve and a right ball valve of the combined three-valve set (2) are respectively clamped between an upper pressing block (15) and a lower pressing block (15) which are provided with sealing rings and are pressed and fixed through 4 screws, a balance ball valve component is arranged in the upper pressing block (10) and is integrated with the upper pressing block (10), the upper pressing block (10) and the lower pressing block (15) are internally provided with a left vertical channel and a right vertical channel which are penetrated through by through holes from bottom to top, two ends of a balance valve in the upper pressing block (10) are communicated with the left channel and the right channel, the combined three-valve group (2) is formed together with a left ball valve and a right ball valve, inner thread holes of two stainless steel pitot tubes are screwed on the lower end surfaces of a left through hole and a right through hole in a lower pressing block (15), the small-diameter part of the lower pressing block (15) is arranged in a sealing ring groove and a screw fastening groove, a stainless steel mounting joint with outer threads is sleeved outside the lower pressing block (15), and a pipeline channel passes through the lower pressing block (15) and the upper end surfaces of a left ball valve upper pressing block (10) and a right ball valve upper pressing block (10) to form the combined three-valve group (2);

the temperature sensor lead wire (30) penetrates through a lead wire protective tube (102) of the lower pressing block (15) and passes through a through hole of the upper pressing block (10) to the upper circuit board, the temperature sensor is fixed at the lower end of the lower pressing block (15), and a pipe protective opening (104) and the through hole of the upper pressing block (10) are isolated and fixed through a sealing nut (103);

the back-to-back type pitot tube probe is arranged at the lower end of the combined three-valve group (2) through the probe and an adjustable joint for installation, and a temperature sensor is arranged beside the back-to-back type pitot tube probe.

2. The back-to-back pitot tube flow transmitter of claim 1 wherein the housing is that of an explosion proof junction box (1), the explosion proof junction box (1) having an electrical wire explosion proof outlet hole in the rear side.

3. The back-to-back pitot tube flow transmitter of claim 1 wherein a loose joint is mounted below the combined three valve group (2), the loose joint being a loose joint with a sealing fastener.

4. The back-to-back pitot tube flow transmitter of claim 1, characterized in that, the left and right ball valves of the combined three-valve set (2) are clamped between the upper and lower pressing blocks (15) with sealing rings and are pressed and fixed by 4 screws, the balance ball valve components are installed in the upper pressing block (10) and integrated with the upper pressing block (10), the upper pressing block (10) and the lower pressing block (15) are provided with left and right vertical channels penetrating through from bottom to top, two ends of the balance valve in the upper pressing block (10) are communicated with the left and right channels, and form the combined three-valve set (2) together with the left and right ball valves.

5. The back-to-back pitot tube flow transmitter of claim 1 wherein the upper and lower pressure blocks (10, 15) have temperature sensor lead-out perforations therein and through-hole compression screws for sealing.