Bend flow meter

One, the introduction:
BWG series of bend flow meter as a kind of both young and old measurement products, it has the advantages of measurement are obtained, and gradually widely used in petroleum, chemical, electric power, textile, papermaking, pharmaceutical and other industries liquid, gas and steam flow measurement, utilities and other fields.Is a simple structure, reliable performance, small pressure loss, especially suitable for large diameter, large flow, pressure loss, low viscosity liquid.A sensing element - elbow flowmeter bend sensor suitable for harsh industrial environments, for high temperature and high pressure, humidity, dust, vibration, has good applicability to various harsh conditions in the field, its application and development prospect.
Second, the measuring principle:
BWG series bending tube flowmeter measurement principle is when a fluid at a certain temperature under the condition of a certain pressure flow through a pipe, when it flows through a turn, the fluid will make a corresponding circumferential rotation movement. According to the theory of fluid forced vortex, fluid in a circular motion in pipe and solid state operating in the space circular motion, so fluid will inevitably produce inertial centrifugal force, the size of the centrifugal force and flow velocity of fluid, fluid density and a circular motion the curvature radius of curvature radius (that is, bend sensor) and other factors.
Due to the bend radius of curvature sensor is known, and through the bend sensor density but also by means of the determination of fluid parameters such as temperature, pressure, accurately obtained with host computer so on bend sensor produced by centrifugal force function is just the size of the fluid velocity.As long as you measure the size of the centrifugal force, the centrifugal force can be measured by the size of the bent tube of the lateral pressure difference to characterization.Fluid can be measured in bend pipe flow velocity, velocity multiplied by the cross-sectional area of the pipe and the density of fluid, fluid flow can be degrees are determined.
Three, measuring medium:
1, liquid: hot and cold water, chemical liquid, light body oil.
2, gas, blast furnace gas, coke oven gas, all kinds of single-component multicomponent gas.
3, superheated steam and saturated steam.
4, compressed air.
5, natural gas, the torch gas, liquefied petroleum gas.
Fourth, the basic advantages of bend flow meter:
1, no additional resistance loss, save fluid conveying power consumption, to reduce the operation cost;
2, easy installation, no leakage, no maintenance, wear resistance, can be directly installed on the pipeline welding;
3, high temperature resistance, corrosion resistance, good resistance to vibration, shock, resistance to magnetic;
4, strong adaptability, low range wide, straight pipe requirements;
5, high measuring accuracy, good reproducibility;Measuring accuracy can reach more than plus or minus 1%, reproducibility is as high as 0.2%;
6, long service life.
Five, the structure characteristics and adaptability:
Structure features:
1, bend sensor with + 1.5%, the second table has repeatability accuracy + 0.2%, is the basis of measurement results to guarantee high precision tube flowmeter.Bend flow meter system measurement precision can be up to + 1.0%
2, is a kind of energy-saving of the flow measurement device.Wear-resisting bend sensor, stay to ensure stable jobs for a long period of time.
3, bend sensor can be used directly welded to install, or use flange connection installation, to solve the problem such as "PaoMaoDiLou", greatly reduce the workload of on-site maintenance, save maintenance cost.
Good adaptability:
1, curved pipe flowmeter can measure the steam, gases, liquids and other fluids, its ability of high temperature, high pressure, corrosion, even with a small amount of particles in the fluid and floc can also work.
2, bend sensor can almost work in any complex, poor environmental conditions, such as high temperature, dust, vibration, humidity, such as adverse factors, bend sensor can work normally, above range than 10:1.
3, to the requirement of straight pipe bend sensor is relatively low, generally after reaching top 5 D 2 D can work normally.
4, no matter which kind of bend sensor, bend arc grew up a party for the positive pressure side, connect the positive pressure differential pressure transmitter, differential pressure transmitter prospectus medium and labeling) in detail.In fact, bend sensor is installed in the measurement of ninety degrees of corner, install state in principle can be arbitrary, the space that is in bend sensors as orientation or direction of no strict requirements.
Six, the applicable scope, special pipes can have a wider scope of application)
1, medium: all single-phase fluid, or can be considered a single-phase fluid media such as gas, liquid and steam can be applied elbow flowmeter for flow measurement.
2, pipe diameter, from 25 to 2000 mm (or rectangular pipe).
3, flow velocity, 0.3 ~ 8 m/s (liquid medium), 7 ~ 80 m/s (gas and steam).
4, temperature: 0 ~ 600 ℃.
5, pressure: 0 ~ 10 mpa.
Seven, measuring accuracy:
Elbow flowmeter measurement precision: bend sensor repeat conversion accuracy + 0.2% or less, secondary instrument accuracy + 0.2%, elbow flowmeter supporting the use of differential pressure, temperature, pressure transmitter should reach the accuracy grade of + 0.5% more or less accuracy requirement.System measuring accuracy of 0.5 ~ 0.5 on the Richter scale are unlikely.
Structure:
Bend sensor is divided into "L" type and "S" type two kinds big.Two funding table as you load and wall and guide rail type converter two kinds, including plate mounted is divided into horizontal and vertical type two kinds.(or on-site installation instrument box, meter box size 360 x260x160)
Eight, the classification of bend sensor:
A sensing element - elbow flowmeter bend sensor according to the difference of the installed pipeline is divided into the following three:
1, 90 ° bend sensor used for process pipeline in 90 ° Angle joint, to replace the original bend;
2, 180 ° bend sensor used for straight line, straight pipe replacement parts;
3, 135 ° bend sensor used for process pipeline in 135 ° Angle joint, instead of the elbow.
Two small pieces of different bend sensor welding straight call take pressure, bend arc length larger bearing a positive pressure measuring 90 ° and 135 ° bend sensor based on plane which is formed by the installation process pipeline turn subdivided into the following three types:
1, the positive pressure measurement in vertical bend sensor installation - turn on the formation of the plane for the vertical plane and turning elbow arc grew up a party in the above;
2, negative pressure measurement in vertical bend sensor installation - turn on the formation of the plane for the vertical plane and turning elbow arc grew up a party in the following;
3, horizontal bend sensor - turn the formation of plane for level 180 ° bend sensor only horizontal form, other installations meaningless.
Nine, bend flow meter of the basic composition and function of different parts:
: 1, the bend sensor output rectifier and differential pressure signal, the accuracy of its geometry size is the guarantee of accuracy of measurement.
2, a valve: liquid and gas measurement generally choose straight needle type or Angle valves, steam with high temperature type needle valve or valve welding.
3, drain valve: liquid and gas measurement generally choose two type needle valve, steam with high temperature type needle valve or valve welding.
4, guide pressure pipe: differential pressure transmitter and bend the clamp connection with;Using 14 x2 x3 or 16 of seamless steel tube, the length of parallax pressure transducer and the bend sensor installation distance surface, usually by the user should bring along their own.
5, disc condenser, steam measurement necessary accessories;Connect to bend sensor, liquid level balance is negative pressure side.
Six, three groups: connected to the differential pressure transmitter, degree to the zero point.
7, differential pressure transmitter: bend sensor measurement inside and outside differential pressure, converted to standard 4 ~ 20 ma current signal.
8, pressure transmitter, superheated steam and other gas measurement, the pressure fluctuation is bigger as necessary;Saturated vapor pressure transmitter can be selected and applied to measure the medium pressure, real-time compensation of flow.
9, temperature components: when the temperature of the measured medium is volatile for spare parts, when used in heating metering, need to choose two component temperature, medium temperature, real-time compensation of flow and to participate in the calculation of heat heating water.
10, secondary instrument (or flow converter) : through signal lines connected with the transmitter, the signal lines: the diameter of 1.0 m ㎡ double Yi shielded cable, its length depending on the transducer and secondary instrument distance, generally by the user should bring along their own.Computing (display) parameters such as flow rate, heat, temperature, pressure, RS232 and RS485 serial interface, can match a computer system, 4-20 ma analog output have or 1-5 v, for the user to choose from.
Of the bend flow meter, flow sensor installation requirements:
Bend sensor welding method is used to install the measuring pipe of ninety degrees of corner, install state in principle can be arbitrary, the space that is in the bend sensors as orientation or direction of no strict requirements, generally has the following four install state to choose from:
1, turn level;
2, positive pressure measurement on the vertical installation;
3, positive pressure measurement in vertical installation;
4, any space.
Above four state in bend sensor in principle can be used when installation, but for some of the measured medium, choose the appropriate installation condition, can greatly simplify the installation, debugging, and is of great benefit to improve the system measurement accuracy.So how to choose correct bend sensor installation status is very important.

Eleven, bend flow meter technical parameters:

Twelve, selection of coding: before the bent pipe flowmeter selection, make sure the following content, and fill out the form below.
(1) the name of the measured medium, medium ingredients or density.
(2) the minimum flow, maximum flow, flow, temperature and pressure.
(3) process pipe diameter, wall thickness, material, sensor installation position.
Note: according to the customer's specific requirements, our company can undertake the bend sensor renovation project, for big diameter, users will be decreased and the purchasing cost.

13, curved pipe flowmeter selection table:

Twenty, nominal diameter code table:

Notes on 14, design selection and order

1, pipe size: diameter x wall thickness (mm);
2, measuring medium name: medium density (kg/m3);
3, set the maximum flow: meter on the range of limit (kg/h or m3 / h);
4, process of minimum flow: (kg/h or m3 / h);
5, work pressure (Mpa);
6, work temperature: (° C);
7, such as with our company, please provide together: intelligent flow totalizer.especially pressure range, or pressure transmitter type, range;Temperature range, or models, range temperature transmitter.