The integration of bend flow meter

Products overview:
ZW - LGW seriesThe integration of bend flow meterAs 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 working principle:
ZW - LGW seriesIntegration of bend flow meter 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.The calculation is as follows:
Type (1) through the pipe bending is given the average flow velocity of fluid and the differential value of function:
V = a (P1, P2)/rho beta -- -- -- -- -- -- -- -- (1)
Among them: V - average flow velocity of fluid;
A - the integrated flow coefficient, a = f (bend bend diameter ratio, Reynolds number and power of medium viscosity, pipe roughness, etc.), especially to the influence of the bending diameter ratio zui is important:
P1 and P2 - curved pipe, the lateral pressure difference;
The density of rho - fluid;
Beta - index;
Calculate the average flow velocity V, can function expression for computing the flow:
Q = S * V * rho -- -- -- -- -- -- -- -- -- -- - (2)
Type:
S - bend cross-sectional area;
V - average flow velocity of fluid;
Applications:
ZW - LGW seriesIntegration of bend flow meter in conjunction with the special intelligent instrument or conversion module, can meet the electrical, thermal, metallurgical, chemical industry, urban water supply heating, various measurement of different industries such as building air conditioning, output, etc.
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.
Four, the main features:
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 technical parameters:
Suitable for special pipes (may be 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.
6, the accuracy of measurement: 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 ~ 1.5 on the Richter scale are unlikely.
Six, 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.

Seven, 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.
Eight, 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.
Nine, 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.
Ten, bend flow sensor installation:

Liquid measurement series:

1, the differential pressure transmitter should be installed at the bottom of the bend of the sensor, make the gases in the pressure tube
Get back in the pipeline.If the condition is differential pressure transmitter must be installed above the bend sensor, and a valve connection leads to pressure pipe should be down, and then slowly turn up, connected to the differential pressure transmitter.
Above 2, measured liquid temperature higher than 100 ℃, the root valve selects high temperature type and add the cooling plate.
Gas measurement system:

1, for installation and maintenance convenience, differential pressure transmitter installed in the pipe bending down to the bottom of the sensor.
2, in order to make the moisture in the gas of less as far as possible into the guide tube, with body tilted upward around 15 ° Angle.
More than 3, measured gas temperature higher than 100 ℃, the root valve selects high temperature type and add the cooling plate.
The steam measurement system:

1, disc condenser disk to level, and take the pressure at the same horizontal plane.
2, differential pressure transmitter should be installed at the bottom of the bend of the sensor, the gas emissions back to the pipe in the pipe.If the condition is differential pressure transmitter must be installed above the bend sensor, the requirements and root valve connection of pressure pipe should be down, and then slowly turn up, connected to the differential pressure transmitter.
Temperature transmitter installation:

1, temperature transmitter for two wire system 4 ~ 20 ma output.
2, the installation position should be 2 d ~ 5 d bend sensor downstream.
3, temperature transmitter with vertical pipe or sloping direction of fluid flow and the pipe reverse installation.
4, pipe at high temperature, try to stay away from heat flow in pipe by insulation when necessary, make the transducer working environment temperature is lower than 60 ℃.

Pressure transmitter installation:

1, two wire pressure transmitter for 4 ~ 20 ma output.

2, the installation position should be bent pipe sensor is less than 2 d.
3, measured medium is liquid, gas pressure position should be the upper surface of the pipe, apply pressure when the steam measurement location in the side of the pipe.
4, measured medium temperature over 80 ℃, the cut-off valve and transmitter and condensation between curved cooled to below 80 ℃.

Eleven, parameter table:

Selection code: 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 big flow, small 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.

Twelve, selection of coding:

Nominal diameter code table:

13 order, design notes:

When you place an order, please provide the following conditions in order to help the correct choice of the specifications of the flowmeter and coefficient.

1, pipe size: diameter x wall thickness (mm);

2, measuring medium name: medium density (kg/m3);

3, set the flow range: meter range of upper limit and lower limit (kg/h or m3 / h);

5, work pressure (Mpa);

6, work temperature: (° C);

7, such as wei in my company, please provide together: intelligent flow totalizer.especially pressure range, or pressure transmitter type, range;Temperature range, or models, range temperature transmitter.

After-sales service commitment:

1, from the date of signing of the contract, I in the way provided for products of the company offers free maintenance and maintenance service, commitment to lifelong maintenance service;

2, jiangsu wei measurement and control instrument co., LTD. Sales manager will be in regular contact with customers, understａnd the usage of products, and solve the problems of the customers to use in the process of produce, free of charge to provide technical support;

3 the man-made damage is found, the warranty period, our company is responsible for the maintenance, and the resulting maintenance fee;

4, product quality problems or are not satisfied with product, the user can choose unconditional return, wei tt&c don't charge any fees, appear quality problem, bear the freight back and forth.