Probe flowmeter

Products overview:

ZW - TRB seriesProbe flowmeterUsed for high temperature of superheated steam flow measurement.The meter adopts the calibration in advance good, can feel the speed of total pressure and static pressure and temperature sensor as the feeling, the secondary instrument used for signal processing, according to a certain operation formula calculation, and the results show that flow integrating instrument, the transmitting unit with piezoelectric type pressure and differential pressure transmitter.The utility model compared with the orifice meter, wide measuring range, high precision, not affected by the flow change.Without the loss of pressure, can save a lot of energy.Small volume, good reliability, stable operation, easy installation and maintenance.

Second, the working principle:

ZW series - TRB probe flowmeter remarkable trap technology is still in its advanced sensor structure, due to take pressure hole at the end of the cut bamboo probe only pipe center, the tube without any other electronic components and pressure components, and to 16 mm hole and the total pressure from pressure 14 mm of hydrostatic pressure hole completion ideal scheme of double general formula prevents clogging.Formed between the piping and testing stem and extremely stable differential pressure signal extraction process, ensure the probe precise measurement.Probe is according to the working principle of dynamic pressure shift static pressure, flow measuring head surface measuring hole measure of total pressure, fluid flow after measuring head surface holes to measure static pressure of the fluid.According to the "hard equation can get velocity and differential pressure gauge head place has the following relationship:

V: velocity measuring head, m/s

Δ Ρ: probe flowmeter flowmeter to measure differential pressure, Pa

Rho: density measured medium, kg/m3

Kv: coefficient of flow meter

Differential pressure flow meter, according to the following formula to calculate the flow: Q = alpha beta gamma AV x 3600

Q: fluid and flow, m3 / h

Alpha: velocity distribution coefficient

Beta: blocking coefficient

Gamma: sectional correction coefficient

A: pipe nominal cross-sectional area, the m2

V: velocity measuring head, m/s

Applications:

ZW series - TRB probe flowmeter is widely used in petroleum, petrochemical, chemical, natural gas, water treatment, brewing and other industrial sectors in all kinds of liquid, gas, steam flow of accurate measurement and measurement.Is an ideal version of the traditional flowmeter.

Four, the main features:

1, the precision is high.Accuracy can reach above 1%.Because of its main parts machining accuracy high, with three over ten thousａnd of the standard instrument for accurate calibration table, to avoid the probe error measurement error brought by production technology, and selects the high precision differential pressure transmitter and pressure transmitter, ensures that each product of high precision.These high-tech advantages, tsinghua university, especially the table calibration system, such as orifice plate, vortex street flowmeter can achieve.

In range and high precision in a wide range, namely in the rated flow range of 5% 99% are to keep the measuring accuracy of 1%.The orifice meter under 30% rated flow basic cannot be used.

Maintain high precision for long.Basic principle is to probe flowmeter total pressure, static pressure through the pinhole and guide tube to differential pressure, pressure sensors, as long as the aperture jams, even with sundry, hang dirty, can accurate transmission pressure without affecting the accuracy.For conducting medium pressure tube do not flow, sundry difficult in jams, so can keep for a long time and high precision.

2, wide applicable scope.A wide applicable medium: measurable vapor (saturated, overheating), air, gas, natural gas, all kinds of chemical material solution, all kinds of gas, liquid, water, oil, etc.;High medium temperature zui allowed 650 degrees Celsius, high pressure zui allow 25 mpa.Secondly, wide flow range of application: medium flow measuring 0.1 ton /, can measure 5000 tons /.Three wide applicable medium pipeline cross section shape is: the meter geometry of medium pipeline section requirements, such as round, oval, square, rectangle, lozenge, etc are applicable.

3, high reliability.All electronic components of the flowmeter from the test medium and pipeline, and only stainless steel probe in the medium, the reliability is high.By contrast, vortex, such as electromagnetic, ultrasonic flowmeter, electronic measuring element must be placed in the measured media such as steam inside or close to the measured medium pipeline, poor working conditions.Such as external vibration or high medium temperature, impurities, such as vortex flowmeter accuracy will drop even unable to work.

4, no pressure loss.A measuring element is 10-20 mm diameter of the probe, the cross-sectional area is small, almost no resistance, no pressure loss.And after the throttle orifice flowmeter pressure loss is very large.

5, simple structure, convenient installation.The meter just punch a diameter of 30 mm holes in medium pipeline, weld the flange at around the base, the probe can be easily through the tight, loose bolts packing and unpacking, maintenance is very convenient.

6 and intelligent.Directly by the digital instrument display medium pressure, temperature, pressure difference, the instantaneous flow and cumulative flow, etc., and can be stored through a computer, printing and other processing.

Five, the technical parameters:

1, specifications: (- DN5000 (mm);Insert: DN500 - DN5000 (mm);

2, the measurement accuracy: + / - 6.0%;Repeatability: + / - 0.1%;

3, scope: volume flow: 10:1;Mass flow rate: 8;

4, work stress: velocity-equalizing tube without functional: 20 mpa or less;Velocity-equalizing tube can be put forward: 10 mpa or less;

5, fluid temperature: 450 ℃ or less;

6, medium viscosity: 30 or less cp (crude oil);

Main components:

1, probe according to pipe diameter custom, with flange installed on the pipe, made of stainless steel refined but become, according to the various parameters of the users with high precision wind tunnel laboratory simulation in tsinghua university, probe characteristic curve and database, used for calculation.

2 is to display the measured results, flow totalizer.especially secondary instrument.Through wires connected to each transmitter and thermometer, the motherboard is equipped with advanced CPU and the application software, can use the display window and switch button to setup, calibration and the parameters display.

3, differential pressure transmitter will probe the differential pressure signal is converted into 4-20 madc analog current signal.

4, pressure transmitter in the gas flow measurement with pressure compensation.

5 in gas flow measurement, temperature transmitter temperature compensation.

6, dc power supply for pressure transmitter, differential pressure transmitter power and thermal resistance thermometer.

Seven, operation and maintenance:

The preparing work before put into operation:

1, sensors installed correctly:

Complete sensors installed in the line, must carefully check before put into operation, require welding is firm, in the right direction, not leak, strictly proper insertion depth, etc.

2, instrument calibration:

Sensor matching instrument differential pressure transmitter and intelligent flow integrating instrument (there could be pressure transmitter and temperature transmitter), etc.Must be after inspection and calibration, can be put into use.The instrument measuring range to conform to the requirements of the sensors and the measured medium.Such as measured zui large air flow Qmax = 5000 m3 / h, the calculation to calculate differential zui big value of sensor

Delta Pmax = 0.6 Kpa, the measuring range of differential pressure transmitter should be set-up of 0 ~ 0.6 Kpa, the corresponding output 4 ~ 20 madc current signal.For universal, flow totalizer.especially should according to the real-time flow range, differential pressure range, medium density, temperature, pressure, flow operation requirements, etc., prior programming configuration, input totalizer.especially can correct operation and make sure totalizer.especially display traffic.

3, instrument wiring correct:

Sensor and differential pressure transmitter, flow integrating instrument of measuring system, such as supporting the power cord, signal output to the input line between instrument, control and alarm, etc., in various instrument wiring board (also known as terminal board) are clearly marked, is must confirm and don't choose to use, before the operation of the instrument connection to check again and again.In order to do the preparing work before put into operation, in addition to read the instruction for use, you should also read the differential pressure transmitter operation instruction handbook ", "operation instruction handbook" intelligent flow totalizer.especially etc, comply with the instruction manual for the guidance of work.

The flow operation of work:

1, the measurement system is closed:

Operation of preparatory work has been completed, the medium to be measured with flow process piping, sensor measuring system is temporarily closed, then should make three balancing valve is fully open valve group, high pressure valve Pl P2 and low pressure valve closed.Meter is in a state of power supply, preheating about 15 minutes.

2, open measurement systems:

Instrument after preheating, open measurement system.Open the Pl on three valve group and P2 valves, balance valve is still in the open.At this time, the differential pressure transmitter has filling the measured medium (gas or liquid), open the drain valve on the transmitter, quickly closed after discharge dirty liquid or gas.Then close three the balance valve on the valve group, transmitter that is entered into a state of differential pressure measurement.Output and the corresponding signal current differential delta P I delta P from the signal current value (m A) to calculate the pressure delta P values (KP) A.Also flow totalizer.especially into work state, show the measured medium flow.

If the above work all goes well, the flow meter works well, commissioning work is complete, delivery production use.

Eight, and blockage of the sensor design.

Probe flow probe's unique design thoroughly get rid of the past several average probe easily blocked, the characteristics of accuracy is not high, make a source of measurement accuracy, repeatability and reliability to a new height.

Just when switched on, the fluid in the pipeline under the action of static pressure, into the pipe bending, quickly formed a pressure balance state.When pressure balance formation fluid in high pressure pipe inlet, detour, no longer into the bend.

Probe type of flow sensor is high, low take pressure hole held in nature

In general, dust, sａnd and particles under the action of the vortex street force, concentrated in the very back of the probe.This is why the autumn leaves are always in the leeward behind the house.Held in the probe's unique design, coupled with the nature of gravity whereabouts, prevents the particles into, this design essentially prevent the congestion and can create a very stable low voltage signal.

Work continuously probe fundamentally eliminate the possibility of the wall, but in the following cases, still should pay attention to prevent:

1, when the pressure pipe leaking, probe high pressure balance to destruction of impurities in the diameter of the smaller particles are likely to enter the hole.

2, when the pipeline was shut down, because of the brown movement of molecules, small particles of impurities may enter the hole.

3, and frequent system key, formed in high, small particles of impurities may enter the hole, accumulate over a long period, it is possible to probe the jam.

4, medium contains a large number of biological species, or containing fibrous material, may also cause the probe of the jam.

Nine, form a complete set of scheme selection:

1, is according to the measured medium, and the user use the pipe inner diameter, working temperature, working pressure and flow design and production.

2, ZW - 3051/1151 dp series differential pressure transmitter or other types of differential pressure transmitter.

3, ZW - 308 series pressure transmitter, or other type of pressure transmitter.

4, temperature transmitter, or other type of temperature transmitter.

5, ZW - XMJA series or other types of flow totalizer.especially flow integrating instrument.

6, of this intelligent velocity-equalizing tube flowmeter, pressure compensation can take temperature, and can show the instantaneous flow and cumulative flow medium medium temperature, the pipe, the pipe pressure and differential pressure equivalent, equipped with communication interface and 4 ~ 20 ma output.

Ten, device:

1, velocity-equalizing tube flow sensor 1;

1 2, velocity-equalizing tube flow sensor operating instructions;

3, 1 certificate;

4, form a complete set of transmitter instrument and manual and certificate of approval (which can be ordered by the users themselves).

Eleven, product maintenance instructions:

Flow sensor should be performed in the process piping overhaul regular cleaning, there are a number of ways for cleaning, such as air blow test tube accumulated filth;Scrub with kerosene and soft silk net, make each hole to maintain patency.May produce the cause of the failure and remove methods: serial number of failure causes clear way.

1, differential pressure signal output: high and low pressure valve is not open, open the high and low pressure valve.

2, high and low pressure balance valves did not tighten, tighten balance valve.

3, differential pressure signal output is too small, pressure system has a leak phenomenon;Seriously looking for, eliminate the leakage.

4, improper secondary table range selection: uninteresting facts limit pressure transmitter.

5, differential pressure signal output is too large, secondary table range matching is undeserved, augmenting the upper limit, differential pressure transmitter back-pressure aperture jams, cleaning velocity-equalizing tube, eliminate congestion.

Twelve, use notice:

1, the current body shall be full of pipe flow and stability.

2, the fluid being measured should be single phase, the phase constant, the composition of complex fluid must be similar to a single component of fluid can be used.

3, the current body under actual conditions of ReD should be greater than 3 x 104.

4, should guarantee the sensor before and after the straight pipe length requirements.

5, pipe diameter greater than 100 ㎜ as well.

6, 2 d in front of the sensor on the surface of the pipe, should be clean and smooth.

13, selection of coding:

14, design selection and order notes:

1, the name of the measured medium;

2, the biggest, commonly used, flow range (m3 / h);

3, work pressure (Mpa), temperature (℃), the maximum pressure (Mpa), upper and lower temperature (℃);

4, medium density, viscosity,

5, pipe material, inner diameter, outside diameter;

6, the pipe laying and local resistance.

7, you need to display instrument of the measurement and control of form a complete set, please refer to the corresponding specifications, choose the right model or the information provided by our company technical personnel according to your designs for you selection.

8, if you have special want to, please contact our sales department.

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.