The target type flowmeter in low temperature

Products overview:
ZW - BSL seriesThe target type flowmeter in low temperatureIs integrating flow, temperature and pressure detection, the use of advanced microcontroller technology and capacitive pressure sensor, the products have no moving parts, vibration resistance, resistance to impurities, strong anti-interference ability;With simple operation, easy to install, free maintenance, breakdown self check, low operating cost of a series of characteristics.BSL series target flowmeter is the original strain chip (capacitive) target flowmeter measurement principle on the basis of using zui new capacitive force sensor as measure and sensitive components, and use of modern digital intelligent processing technology and developed a new type of flow meters.
Second, the structure and working principle:
1, structure,
ZW - BSL seriesThe target type flowmeter in low temperatureMainly by the measuring tube (shell), new sensors (including choke element), integrating display and output parts.According to the different medium and condition, must choose appropriate sensors, therefore, provide accurate object and parameter measurement, and manufacturers to choose appropriate sensor is the key of the products can be accurate measurement.
2, working principle
When medium in the measurement of pipe flow, because of its kinetic energy and target plate pressure difference, and produce on the target plate force, make the target board of trace amounts of displacement, the force is proportional to the square of the velocity with the media, the size of the target plate force of the target bar transfer, make the sensor elastomer produces trace changes, thereby breaking patches of capacitance bridge balance.Generation and corresponding voltage signal flow force on the target board: by the fluid flow characteristics, the influence of flow rate and is proportional to the square of the voltage produced by the bridge.Its mathematical expression is as follows: F = CdA rho?V2/2,
Type: F choke a force (kg) of
Drag coefficient Cd object
A choke pieces on the measuring tube axial projection area (was)
Rho conditions of medium density (kg/m3)
V medium in the measuring tube average flow velocity (m/s)
Choke (target) accept force F, the rigid connection of transfer (rod) to the sensor, the sensor produces voltage signal output: V = KF
Type: V - sensor output voltage (mV), K - proportionality constant, F - choke piece (target) by force (kg),
The voltage signal after preamplifier, AD conversion and computer treatment, obtains the corresponding instantaneous flow and cumulative total.

Applications:
ZW - BSL seriesThe target type flowmeter in low temperatureHas been widely used in semi water gas, coke oven gas, heavy oil, residual oil metering, asphalt, liquid paraffin, toluene, sulfuric acid, natural gas, methane chloride, flue gas, sewage, water, etc, and other special medium measurement, resolves the problem for many years the industry flow metering.

Four, the main features:
1, suitable for all kinds of pipe diameter: 15-2000 - mm to bigger.
2, suitable for high and low temperature medium: - 196 ℃ to + 450 ℃.Can accurately measure all kinds of room temperature, high temperature, low temperature condition of the liquid, gas, steam, viscous medium and all kinds of fluid flow.
3, high sensitivity, can measure small flow rate, it can measure the low velocity of 0.08 m/s.
4, suitable for high pressure conditions: 0-42 mpa.
5, have no moving parts, high accuracy.
6, good repeatability, is 0.1 0.08% commonly, fast measurement.
Total 7, accurate measurement, high accuracy, measurement can reach 0.2%.
8, good vibration resistance to electromagnetic interference, can dry calibration, and farmar hanging weight method.
9, body material: carbon steel, 304316316 L.
10, mode of power supply: 3.6 V lithium batteries;24 VDC power supply;Double power supply: 3.6 V lithium battery + 24 VDC power supply.
Five, the technical parameters:
1, the measured medium: liquid.Gas;steam
2, nominal diameter pipeline: 15 ~ 300 mm clamp mounting type: 15-600 - mm plug-in: 100 ~ 2000 mm
3, nominal pressure: 0.6 ~ 42 mpa
4, medium temperature: - 20 ℃ ~ 70 ℃ (room temperature).- 196 ℃ ~ + 450 ℃ (high and low temperature type)
5, accuracy: + / - 0.2%, plus or minus 0.5%, plus or minus 1.0%, plus or minus 1.5%, plus or minus 2.5%
6, scope: 1:3, 1:5, 1:10, 1:10 (gas), 1:10 (steam)
7, compensation type: temperature compensation;Pressure compensation
8, repeatability: 0.1% ~ 0.08%
9, the power supply: machine with a built-in 3.6 V lithium batteries;The 24 VDC power supply source;220 vac (only for fission digital tube display)
10, output form: the display reading values;4 ~ 20 ma (two wire system);Pulse;0 ~ 10 v.RS232 / RS485 (optional)
11, the measuring tube material: carbon steel;304;316 l;Can also according to user requirements to provide
12, explosion-proof marks: the Ann model (ExiallCT4) flameproof (ExiallBT4)
13, protection grade: IP65;IP67
Note: meter flange specifications implement GB/T9115.1-9115.4-2000 series standards, pipeline according to user needs production DN6, DN8, DN10 small flow meter, etc.
Six, installation instructions:
1, normal temperature, low temperature, high temperature type flowmeter depending on the different working conditions using horizontal, vertical or inverted type installation (the factory check list shall prevail);
2, medium temperature when + 300 degrees above, the user response to flowmeter shell heat insulation measures are taken to prevent thermal radiation damage to the header (header working temperature for 30 to + 70 degrees c), the same work under medium temperature - 100 degrees, also should adopt anti-freezing measures;
3, to guarantee the accuracy of the flowmeter measurement, requirement set straight pipe before and after;
4, in order to ensure the flowmeter in inspection and replacement does not affect the system work, should try to set the by-pass valve (3) and the cut-off valve (1, 2);
5, due to the need of technology can be used vertical installation, the flow direction of medium under test can be bottom-up, also can from top to bottom, but when ordering should explain to the supplier;
6, flow meter diameter and connected to the pipe diameter size is the same as far as possible, to reduce the flow disturbance, caused by measurement error;
7, flowmeter shell must be reliable grounding, without ground conditions should explain to the manufacturer.
Seven, notable matters of installation:
1, measurement before and after the pipe should be straight pipe, the pipe diameter of straight pipe shall be the flowmeter measurement tube diameter is equal, such as pipe diameter with different pipe diameter same reducer connected to the entrance.Meter length of straight pipe upstream side is generally not less than 6 ~ 20 d, according to different upstream choke typing, downstream straight pipe not less than 3-4 d.Is according to the horizontal position calibration, the flowmeter is generally installed in horizontal pipe is used, when must be installed in vertical pipe, must use weighing method for flow meter vertical install state calibrated, direction of flow shall be from bottom to top.
2, for ease of use and maintenance to prevent flowmeter enabled one-way bearing, downstream of the bypass pipe flow meter installed in parallel the installation of a drain pipe, easy cleaning and scavenging for instrument, for measuring smudgy fluid or easy to solidification and crystallization medium more necessary.Target plate and the measuring tube (table) should coaxial installation, according to a certain diameter of the experiment proved that the target plate and pipe center if deviation from 1 mm up and down, can result in a 1% to 2% of the flow coefficient of deviation, but around 1 mm deviation, the effect is obvious;
3, install, explosion-proof target type flow time, should pay attention to check for explosion-proof marks and explosion-proof certification, explosion-proof equipment are in good condition.
4, for small diameter flowmeter, due to the small diameter flowmeter is relatively heavy, in order to prevent the pipe deformation or vibrate at work, should be on the brace flowmeter.For large diameter flowmeter can not setting up support.

Eight, fault handling:

With breakdown self check program, the user through the display screen can be found in part:

1, when the pipe velocity is zero, the measured medium flow meter of instantaneous flow rate of values are not zero, the main cause of this phenomenon are as follows:

A, levelness, before and after installation flowmeter and target and target pole caused by tilting and produce axial horizontal component of the instantaneous flow exists;

B, flow meter run for a long time, the sensor inner stress release production micro changes;

C, in the process of installation or operation, serious overload caused by zero drift;

You may refer to the above three ways are about flow meter reset steps and methods of treatment.

D, bad earth flowmeter shell;

Processing method: users to ground.

E, target, target and measurement is sundry stuck between;

Processing method: before and after the valve closed flowmeter, excessive parts with tools to loosen flowmeter and bolt connection of the measuring tube, and gently shaking the transition parts or remove and clean up the clutter can be reset as is after.

2, the working process of the flowmeter in appear abnormal value increases, the main cause of this phenomenon are as follows:

A, target and target stem with filamentous and banded sundry;

Methods: reference to deal with sundry method.

B, under the condition of high knot engine-grease, target and target pole have serious engine-grease, make the stress components on the target plate along the measuring pipe axis projection area increase, namely the target piece between the measuring tube and annular flow area is reduced, and under the same flow rate, the sensor stress increases, zui has led to an increased flow of abnormal value;

Processing method: remove the transition parts, use tool to target and target rod and the measuring tube wall engine-grease things clear.

3, measurement error is large, some of the reasons for this phenomenon, its zui the main reason for the following:

A, when installation flowmeter and connection pipe concentricity appear relatively large displacement, sealing gasket is not concentric, thus forming the throttle resistance, greatly influence the flow measured medium;

Methods: adjust the install state.

B, the straight pipe before and after the flowmeter is too short, and directly installed the bend before the flow meter, valve, such as great interference flow components measured medium;

Methods: according to the specifications for installation or real flow field to calibrate the flowmeter.

C, by-pass pipe leakage;

Methods: inspection and replace the by-pass pipe.

D, target sheet wrapped around have banded sundry, increases the target bearing;

Processing method clutter processing method: with reference to the front.

4, flow meter with no signal or no, value for its reason mainly has the following four:

A, power poor contact or fall off;

Methods: for the onboard battery meter, check whether the battery pack, contacts are in good condition, and whether there is a battery.For the power converter,

Check the connection between the connecting wires are in good condition, whether the wire conduction, external power supply source is normal.

B, flow meter circuit damage;

Methods: to return factory repair.

C, screen damage;

Methods: change back to factory.

D, customer reception system failure;

Processing method: check, troubleshooting.

5, flowmeter has zero value, during the operation of the main reasons for this phenomenon are as follows:

A, stress components (target) fall off, lead to weak inductive sensor;

Methods: assembly specifications of the same target.

B, no voltage meter sensor output signal;

Processing method: first of all determine whether the sensor is damaged, the specific method is to see the sensor data have any change.

C, the medium flow rate is too small to be tested, below zui small scale flow meter;

Methods: returned to the factory to replace the mechanical components.

Nine, use notice:
1, before the fluid flow, downstream of the valve should be closed flowmeter, open the upstream of the valve, let the fluid into the meter section.Then slowly open the downstream of the flow meter, valve closed bypass valve at the same time, make the fluid increase slowly, avoid by all means is suddenly opened the valve impact target board damage the instrument.
2, flowmeter after running for a long time, in addition to the target plate, measuring pipe cleaning fouling, hanging heavy method should be adopted to check if there is a change characteristics of the power converter.Hanging method is applied in the center of the target plate is the same as the flow direction of Jordan farmar gravity, adjust instrument, corresponding to the flow force of the upper limit of the flow meter, which according to the type (16.6) to calculate F a, other traffic point are related to weight, read the output signal, check the basic error of each point and linearity."Hang heavy method" in the factory the product specification or other information on the 'is described, also can see.
3, fluid force acting on the target board and the function of the hanging heavy force or have difference, so hang heavy method can not completely replace real flow calibration.To obtain high accuracy, the necessary of real flow calibration is needed.
4, when copying or restructured board, attention should be paid to the machining precision of target board, otherwise will affect the flow coefficient.Experimental data show that for target flowmeter mouth = 0.8, pipe diameter DN = 25 mm, if target 0 01 mm diameter deviation, flow coefficient is 1%.Target plate machining accuracy and surface roughness also have influence on the discharge coefficient.
5, flow meter is running, if discover the output value, check the power conversion system is normal, may be due to the fluid flowing through the target board at its downstream vortex street, caused by vibration in the target bearing, it is about the size and velocity, medium physical parameters (density and viscosity) and so on, can be in force transformation and electrical signals take measures to improve the damping in the system.