LWGY series turbine flow sensor (hereinafter referred to as sensor) is based on the principle of moment balance and belongs to velocity flow meter. The sensor has the characteristics of simple structure, light weight, high precision, good reproducibility, sensitive response, easy installation, maintenance and use, etc. It is widely used in petroleum, chemical, metallurgy, water supply, papermaking and other industries, and is an ideal instrument for flow measurement and energy saving.

The sensor is used together with the display instrument and is suitable for measuring the temperature of the closed pipeline with stainless steel 1Cr18Ni9Ti, 2Cr13 and corundum Al2THE3, hard alloy will not corrode, and there is no fiber, particle and other impurities in the liquid. If it is matched with a display instrument with special functions, it can also perform quantitative control, over-quantity alarm, etc. The explosion-proof type (ExmIIT6) of this product can be used in an environment with explosion hazard.

The sensor is suitable for liquids with a viscosity less than 5×10-6m2/s, for media with a viscosity greater than 5×10-6m2/s liquid, the sensor must be calibrated with real liquid before use.

If the user requires a special type of sensor, the order can be negotiated. If an explosion-proof sensor is required, please indicate it in the order.

LWGY basic turbine flow sensor

1. Structural features and working principles

(1) Structural characteristics

The sensor is of carbide bearing thrust type, which not only ensures accuracy and improves wear resistance, but also has the characteristics of simple and firm structure and easy disassembly and assembly.

(2) Working principle

The fluid flows through the sensor housing. Since the impeller blades have a certain angle with the flow direction, the fluid's impulse causes the blades to have a rotational torque. After overcoming the friction torque and fluid resistance, the blades rotate. After the torque is balanced, the speed stabilizes. Under certain conditions, the speed is proportional to the flow rate. Since the blades are magnetically conductive, they are in the magnetic field of the signal detector (composed of permanent magnets and coils). The rotating blades cut the magnetic lines of force and periodically change the magnetic flux of the coil, thereby inducing an electrical pulse signal at both ends of the coil. This signal is amplified and shaped by the amplifier to form a continuous rectangular pulse wave with a certain amplitude, which can be transmitted to the display instrument to show the instantaneous flow rate or total amount of the fluid. 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:

Where:

f——Pulse frequency [Hz]

k——Instrument factor of sensor [1/m3], given by the calibration sheet. If the unit is [1/L]

Q——Instantaneous flow rate of fluid (under working condition) [m3/h]

3600——Conversion factor

The instrument coefficient of each sensor is filled in by the manufacturer in the calibration certificate, and the k value is set in the matching display instrument to display the instantaneous flow rate and cumulative total.

2. Basic parameters and technical performance

(1) Basic parameters:See Table 1

Table 1

The sensor with diameter of DN 4-DN40 is threaded and has a maximum working pressure of 6.3Mpa;

The sensors with diameters of DN50-DN200 are flange-connected, and the maximum working pressure is 2.5Mpa;

The sensor with a diameter of DN 4-DN10 is equipped with front and rear straight pipe sections and filters.

Our company can provide front and rear straight pipe sections for sensors with a diameter of DN15 or above.

(2) Medium temperature:-20～＋120℃.

(3) Ambient temperature：-20～＋55℃.

(4) Power supply:Voltage: +5-24VDC, Current: ≤10mA.

(5) Transmission distance:The distance from the sensor to the display instrument can reach 1000m.

3. Installation, use and adjustment

(1) Installation

The installation method of the sensor is different according to the specifications, using threaded or flange connection. The installation method is shown in Figure 1, Figure 2, and Figure 3. The installation dimensions are shown in Table 2.

1. Filter 2. Front straight pipe section 3. Impeller 4. Preamplifier 5. Housing 6. Rear straight pipe section

Whole table structure diagram

1. Clamping ring 2. Bolt 4×14 3. Washer 4. Sealing washer 5. Steel wire 1Cr18Ni9Ti-0.8×2.5 6. Filter 7. Seat

Filter structure diagram

Figure 1 Schematic diagram of LWGY-4~10 sensor structure and installation dimensions

Casing 2. Front guide 3. Impeller 4. Rear guide 5. Preamplifier

Figure 2 Schematic diagram of LWGY-15~40 sensor structure and installation dimensions

1. Ball bearing 2. Front guide 3. Expanding ring 4. Housing 5. Preamplifier 6. Impeller 7. Bearing 8. Shaft

Figure 3 Schematic diagram of LWGY-50~200 sensor structure and installation dimensions

Figure 4 Schematic diagram of sensor and display instrument wiring

Table 2

The sensor can be installed horizontally or vertically. When installed vertically, the fluid direction must be upward.The pipe should be full and free of air bubbles.During installation, the liquid flow direction should be consistent with the direction of the arrow indicating the flow direction on the sensor housing. The upstream end of the sensor should have a straight pipe section of at least 20 times the nominal diameter, and the downstream end should have a straight pipe section of no less than 5 times the nominal diameter. The inner wall should be smooth and clean, without defects such as dents, scale and peeling. The sensor's pipe axis should be aligned with the adjacent pipe axis, and the gasket used for connection and sealing should not penetrate deep into the pipe cavity.

The sensor should be kept away from external electric and magnetic fields, and effective shielding measures should be taken when necessary to avoid external interference.

In order to ensure that the normal liquid transportation is not affected during maintenance, it is recommended to install a bypass pipe at the installation location of the sensor.

When the sensor is installed outdoors, please make sure that the amplifier and the plug are waterproof. The wiring of the sensor and the display instrument is shown in Figure 4.

When the fluid contains impurities, a filter should be installed. The filter mesh is determined according to the flow impurities, generally 20 to 60 mesh. When the fluid is mixed with free gas, a gas eliminator should be installed. The entire pipeline system should be well sealed.

Users should fully understand the corrosion conditions of the measured medium and strictly prevent the sensor from corrosion.

⑵ Use and adjustment

◆ When using, the liquid to be tested should be kept clean and free of impurities such as fibers and particles.

◆ When the sensor is used for the first time, the sensor should be slowly filled with liquid, and then the outlet valve should be opened.

It is strictly forbidden to subject the sensor to the impact of high-speed fluid when it is in a liquid-free state.

◆ The maintenance period of the sensor is generally half a year. When inspecting and cleaning, please be careful not to damage the parts in the measuring chamber, especially

Especially the impeller. Please pay attention to the position relationship between the guide and the impeller during assembly.

◆ When the sensor is not in use, clean the internal liquid and add protective covers on both ends of the sensor to prevent dust from entering.

Then store in a dry place.

◆ The filter should be cleaned regularly when in use. When not in use, the liquid inside should be cleaned. Like the sensor, add a dust cover and store in a dry place.

◆ The transmission cable of the sensor can be laid overhead or buried underground (when buried underground, it should be covered with an iron pipe.)

◆ Before installing the sensor, first connect it to the display instrument or oscilloscope, turn on the power, blow or turn the impeller by hand to make it rotate quickly and observe whether there is any display. If there is a display, install the sensor. If there is no display, check the relevant parts and eliminate the fault.

3. LWGYA turbine flow transmitter

LWGYA turbine flow sensor is based on LWGY basic turbine flow sensor and adds 24VDC power supply and 4-20mA two-wire current transmission function. It is particularly suitable for use with display instruments, industrial computers, DCS and other computer control systems.

Please read the second part of this manual "LWGY Basic Turbine Flow Sensor" for the flow measurement range of each caliber of this transmitter, sensor structure size, installation method, maintenance, etc.

Flow calculation formula: Q=QF

Where: Q ——actual flow, m3/h

      QF——Flow measurement upper limit, m3/h, see Table 1

I ——current output, mA

Transmitter power supply voltage: 24V, (12V-30V)

Relationship between supply voltage and load resistance: RLMAX=-50

Where: RLMAX——Maximum load resistance,Oh

U ——supply voltage, V

Figure 5

Transmitter wiring: A(+)———24V+ B(-)———0V

4. LWGYB turbine flow sensor

   LWGYB on-site display turbine sensor is based on LWGY basic turbine flow sensor, powered by battery, and adds on-site display function. This flow meter is a new flow measurement instrument that integrates sensor and display calculation, developed using advanced ultra-low power single-chip microcomputer technology. Compared with the traditional measurement system composed of turbine flow sensor and secondary instrument, it has obvious advantages such as small size, light weight, intuitive and clear display reading, high reliability, no influence from external power supply, lightning resistance, and low set cost. It can be widely used in liquid flow measurement in petroleum, chemical, light industry, food and other industries. This product has superior performance and reaches the advanced level of similar international products.

1. Main technical indicators

(1) Display mode:

Double-row LCD display, the method is as follows:

L XXX.X Four-digit instantaneous flow rate (m3/h)

XX.XXXXXX eight-digit cumulative flow (m3）

Figure 6

(2) System low power operation:A 3.3V10AH lithium battery can be used continuously for more than 5 years.

(3) Cumulative flow:The display accuracy is automatically expanded and the accumulated flow value can be cleared.

(4) Instrument factor:Can be inserted on site.

(5) Power-off protection:The instrument coefficient and accumulated flow value will be retained for ten years even if the power is off.

2. Method for setting the three-point coefficient double-row LCD display (only for authorized engineers):

    Open the front cover of the instrument and pressKey andFThe instrument enters the setting state. The first digit of the upper row shows 1, indicating that the instrument coefficient of the first point can be set. The last four digits of the upper row can set the sensor output pulse frequency value of the corresponding point, and the eight digits of the lower row can set the instrument coefficient value of the point.

First the highest bit flashes, press the, add 1 to the desired value, press the shift key, the flashing position moves right, and then useWhen the flashing bit moves to the last digit, pressThe parameter can be reset by pressing the key. The instrument coefficient format is XXXXXX.XX

After checking, pressFkey to enter the setting of the next instrument coefficient. The setting method and format are the same as above.

After setting the three-point coefficients, continue to pressFThe instrument enters working state, the upper row displays four digits of instantaneous flow, and the lower row displays eight digits of accumulated flow.

In working state, pressFkey to clear the accumulated total.

Note: Using three-point instrument coefficients to correct the nonlinearity of the flow sensor requires the user to clearly know the instrument coefficients corresponding to different flow points (frequency points) of the sensor, namely F1——K1, F2——K2, F3——K3.

5. LWGYC turbine flowmeter (with transmitter)

LWGYC turbine flow sensor is based on LWGYB turbine flow sensor and adds 24VDC power supply and 4-20mA two-wire current transmission function. It is particularly suitable for use with display instruments, industrial computers, DCS and other computer control systems.

It has the functions of on-site display and remote transmission.

The operation method of setting the instrument coefficient refers to the instructions in the setting part of "IV. LWY type turbine flow sensor", the differences are as follows: 

Three-point coefficient double-row LCD display operation method:

Open the front cover of the instrument and pressFKey andkey, the instrument enters the setting state.

At this time, the first digit in the upper row is 1, and the other four positions are used to enter the sensor frequency value of this point. The instrument coefficient of this point can be placed in the lower row. The instrument coefficient format is XXXXXX.XX.

First the highest bit flashes, press the, add 1 to the desired value, press the shift key, move the flashing position to the right, and then use the keySelect the value of this digit..., when the flashing bit moves to the last digit, presskey to reset the parameter;

After checking, pressFPress the key to enter the next group of coefficient settings. The first number on the upper row displays 2, and the rest are the same as above.

After checking, pressFPress the key to enter the next group of coefficient settings. The first number on the upper row displays 3, and the rest are the same as above.

If you continue to pressFThe instrument sets the fourth parameter - full-scale flow. At this time, the full-scale flow value corresponding to 20mA is entered in the lower row. For example, if a 4mm instrument corresponds to 250L/h, 250 can be entered at this time; if 50 is set, 50L/h automatically corresponds to 20mA.

After setting the parameters and checking that they are correct, pressFThe upper row displays five digits of instantaneous flow and the lower row displays eight digits of accumulated flow.

In working state, pressFkey to clear the accumulated total.

Th