Liquid turbine flowmeter

I. product overview
ZW series - LWGY liquid turbine flowmeter is adopted advanced ultra low power single chip microcomputer technology of turbine flow sensor and display the integration of integrating new intelligent instrument, adopts double row at the scene of the liquid crystal display, with compact bodies, intuitive and clear reading, high reliability, without external power supply interference, lightning resistance, low cost, obvious advantages. The instrument is equipped with three-point correction of instrument coefficient, intelligent compensation of non-linear instrument coefficient and field correction. The high definition liquid crystal display displays instantaneous flow rate (4 significant digits) and cumulative flow rate (8 significant digits with zero clearing function) at the same time. All valid data is held for 10 years after power failure. All these turbine flowmeters are explosion-proof products, and the explosion-proof grade is ExdIIBT6.
This type of turbine flowmeter can be divided into lwgy-b type and lwgy-c type according to the power supply mode and whether it has remote signal output.
Type B: power supply adopts 3.2v10ah lithium battery (it can run for more than 4 years continuously); No signal output function.
Type C: the power supply USES 24VDC external power supply, output 4-20ma standard two-wire current signal, and according to different site needs, can increase RS485 or HART communication.
Ii. Working principle
The working principle of ZW - LWGY series liquid turbine flow meter is a fluid flowing through the sensor shell, as a result of the impeller blade and flow to a certain point of view, the impact of fluid blade with rotational torque, to overcome the friction torque and fluid resistance, blade rotation speed stability after the moment balance, under certain conditions, the speed is proportional to the velocity of flow, because the blade has a magnetic conductivity, it is in the signal detector (composed of * magnetic steel and coil) magnetic field, rotating blade cutting lines, periodically changing coil magnetic flux, so that the coil ends induction electrical pulse signal, the signal after amplifier amplification plastic, A continuous rectangular pulse wave with a certain amplitude can be formed, which can be transmitted to the display instrument to display the instantaneous flow of the fluid and the cumulative amount. Within a certain flow range, the pulse frequency f is proportional to the instantaneous flow rate Q of the fluid flowing through the sensor, and the flow equation is: Q=3600 f/k; Type:
F -- pulse frequency [Hz];
K -- instrument coefficient of the sensor [1/m3], given by the check list. If I take 1/L as the unit
Q -- instantaneous flow rate of fluid (under working condition) [m3/h];
3600 -- the conversion factor.
The instrument coefficient of each sensor is filled in by the manufacturer in the verification certificate, and the value of k is set in the supporting display instrument to show the instantaneous flow and cumulative total.
Iii. Application:
Zw-lwgy series liquid turbine flowmeters are widely used in petroleum, chemical industry, metallurgy, water supply, papermaking, environmental protection, food and other fields. They are suitable for measuring the liquid in the closed pipeline which has no corrosive effect with stainless steel, corundum and hard alloy, and has no impurities such as fiber and particle. If it is used together with the display instrument with special function, it can be used for automatic quantitative control, over-alarm and other purposes.
Iv. Main features:
1. High quality alloy turbine flowmeter has higher stability and corrosion resistance;
2. Imported high-quality special bearing with long service life;
3. The metering room is isolated from the ventilation room to ensure the safety of the instrument;
4. It can detect the temperature, pressure and flow rate of the measured gas, and can automatically track and compensate the flow rate, and display the gas volume accumulation under standard conditions (Pb=101.325KPa,Tb=293.15K); Real-time query temperature and pressure value.
V. technical parameters:
1. High accuracy, generally up to 1%R, 0.5%R, high precision up to 0.2%R;
2, good repeatability, short-term repeatability up to 0.05%~0.2%, is due to the good repeatability, such as regular calibration or online calibration can get very high accuracy, in the trade settlement is the preferred choice of the flow meter;
3. It is equipped with three-point correction of instrument coefficient, intelligent compensation of non-linear instrument coefficient and on-site correction
4. Keep all valid data for 10 years after power failure;
5. Wide range, medium and large caliber up to 1:20, small diameter 1:10;
6, compact and lightweight structure, easy installation and maintenance, circulation capacity;
7, suitable for high pressure measurement, the meter body does not need to open, easy to make high pressure instrument;
8. There are many types of special-purpose sensors, which can be designed according to the special needs of users for various types of special-purpose sensors, such as low-temperature type, two-way type, downhole type, sａnd mixing special-purpose type, etc.;
9, can be made into insert type, suitable for large diameter measurement, pressure loss is small, low price, can be taken out, installation and maintenance is convenient.
Vi. Display function:
1. Display standard instantaneous flow and standard cumulative flow;
2. Display instantaneous flow and cumulative flow under working conditions;
3. Display current pressure, temperature and battery voltage;
Display date and clock.
Vii. Model and standard configuration:
Zw-lwgy type: basic type sensor. No field display, output pulse signal. Standard for non - explosion - proof products.
Zw-lwgy-a type: 4-20ma transmitter. Note: without field display, output 4-20ma standard current signal. Standard for explosion-proof products (ExdIIBT6).
Type zw-lwgy-b: intelligent field display. Description: double LCD head, display instantaneous flow and cumulative flow at the same time, lithium battery power supply, battery power can be used for more than three years, no signal output. Standard for explosion-proof products (ExdIIBT6).
Zw-lwgy-c type: intelligent integrated type. Description: double LCD head, display instantaneous flow and cumulative flow at the same time, external supply 24VDC, output 4-20 mA standard current signal, standard for explosion-proof products (ExdIIBT6).
Viii. Possible problems caused by installation:
1. Insufficient length of upstream and downstream straight pipe segments;
2. There is a big deviation between the inside diameter of the instrument measuring pipe and that of the pipe fitting;
3, installation of different heart, sealing pad convex tube;
4. Reverse instrument flow direction;
5. Detection elements are covered with impurities;
6. Low detection sensitivity and low flow rate;
7, pipeline leakage (such as installed in the underground pipeline, small leakage is not found), valve leakage, bypass valve leakage caused by the cumulative flow (total) is small;
8. Accurately measure the influence of two-phase flow and pulsating flow.

Ix. Precautions for installation and use:
1. Before operation, the instrument coefficient shall be set, and the power can be transmitted only after careful inspection to ensure the correct connection and good grounding of the flow meter;
2. The flow meter should be cleaned, inspected and rectification regularly. For the flow meter with lubricating oil or cleaning liquid injection port, the lubricating oil or cleaning liquid should be injected regularly according to the requirements of the manual to maintain the good operation of the impeller;
3. Monitor the status of the display instrument, evaluate the reading of the display instrument, and timely check any abnormality;
4. Keep the filter unblocked. The blockage of the filter can be judged from the increase of the pressure gauge reading difference at the inlet and outlet.
5. Turbine flowmeters for trade settlement must be calibrated regularly to ensure accuracy and reliability of measurement.

X. structure and installation:
1. The instrument is installed with threaded connection and flange link;
2. During installation, the direction of liquid flow should be consistent with the direction of arrow indicating the flow direction on the sensor housing, and the upstream straight pipe segment should be 6D, and the downstream straight pipe segment should be 5D (D is the measured inner diameter of the tested pipe).
3, the sensor should be away from the external magnetic field, if it can not be avoided, should take necessary measures;
4. In order not to affect the normal delivery of liquid during maintenance, bypass pipes shall be installed outside the straight pipe section at both ends of the sensor;
5. When the sensor is installed in the open air, please make the amplifier plug waterproof;
6. The connection between the sensor and the display instrument shall be selected according to the power supply of the amplifier. Please refer to the relevant operating instructions for details.
11. The following points shall be noted during use or after shutdown:
1. Keep the tested liquid clean and free from impurities such as fiber and particles.
2. At the beginning of use, the sensor should be slowly filled with liquid, and then open the outlet valve, the sensor is prohibited in the state of no liquid by high-speed fluid impact.
3. The maintenance cycle is generally half a year. During maintenance and cleaning, please pay attention not to damage the parts in the measuring chamber, especially the impeller. Please pay attention to the position relation of guide piece and impeller when assembling.