的用途：JL－LWGY涡轮流量传感器与显示仪表配套组成涡轮流量计。 First, the use of turbine flowmeter : JL-LWGY turbine flow sensor and display instruments supporting the turbine flowmeter. The sensor has the characteristics of high accuracy, good repeatability, long life and simple operation. The turbine flowmeter can be widely used in petroleum, chemical, metallurgy, papermaking and other industries to measure the instantaneous flow volume and total volume of liquids.
Second, the principle of turbine flowmeter: A turbine is placed in the center of the pipeline, and both ends are supported by bearings. When the fluid passes through the pipeline, it impinges on the turbine flowmeter blades and generates a driving torque to the turbine flowmeter, which causes the turbine flowmeter to overcome the frictional torque and the fluid resistance torque to generate rotation. In a certain flow range, for a certain fluid medium viscosity, the rotational angular velocity of the turbine flowmeter is proportional to the fluid flow velocity. Therefore, the fluid flow velocity can be obtained by the rotational angular velocity of the turbine flowmeter, so that the fluid flow rate through the pipeline can be calculated. The rotational speed of the turbine flowmeter is detected by a sensing coil installed outside the casing. When the turbine flowmeter blade cuts the magnetic field lines generated by the permanent magnetic steel in the casing, it will cause the magnetic flux in the sensing coil to change. The sensor coil sends the detected magnetic flux periodic change signal to the preamplifier, amplifies and shapes the signal, generates a pulse signal proportional to the flow velocity, and sends it to the unit conversion and flow accumulation circuit to obtain and display the accumulated flow value; At the same time, the pulse signal is also sent to the frequency current conversion circuit, which converts the pulse signal into an analog current quantity, and then indicates the instantaneous flow value.
Third, the characteristics of the turbine flow meter: ★ Small pressure loss. ★ It has high anti-electromagnetic interference and anti-vibration ability, reliable performance and long working life. ★ Adopting advanced ultra-low power single-chip microcomputer technology, the machine has strong functions, low power consumption and superior performance. Intelligent flow display with non-linear accuracy compensation. The accuracy of the correction formula is better than ± 0.02%. ★ The meter coefficient can be set online by keys and can be displayed on the LCD screen. The LCD screen is intuitive and clear with high reliability. ★ Use EEPROM to protect the accumulated flow and meter coefficient from power failure. Protection time is more than 10 years.
Main technical parameters of turbine flowmeter:
★ Flowmeter specifications, basic parameters and performance indicators ★ Accuracy: 0.5, 1.0; ★ Conditions of use:
1. Ambient temperature: -20 ℃ ～ 50 ℃; 2. Measured medium temperature: -20 ℃ ～ 120 ℃; 3. Atmospheric pressure: 86Kpa ～ 106Kpa; 4. Explosion-proof grade: ibⅡBT4. ★ Signal transmission distance: sensor to display The distance can reach 1000m.
V. Turbine flowmeter electrical characteristics: 1. Turbine flowmeter display mode: (1) LWGY remote transmission display: pulse output (with display instrument); (2) LWY on-site display: liquid crystal display cumulative flow rate, unit (m³) liquid crystal display Instantaneous flow, unit (m³ / h) (3) LWGB turbine flow transmitter: (with display instrument). 2. Turbine flowmeter output function: (1) LWGY pulse output, pp value is determined by the power supply; (2) LWY can have pulse output or 4 ~ 20mA two-wire current output; (3) LWGB 4 ~ 20mA two-wire system Current output. 3. Turbine flowmeter power supply: (1) LWGY: DC5 ~ 24V; (2) LWY: 3V lithium battery installed in the instrument can be used continuously for 3 to 5 years; (3) LWGB: DC24V.
仪表结构及安装方式：1、 仪表安装采用法兰连接、螺纹连接及夹装式；2、 安装时液体流动方向应与传感器外壳上指示流向的箭头方向一致，且上游直管段应≥6DS，下游直管段应≥5DS(DS为被测管道实测内径)。 6. Turbine flowmeter instrument structure and installation method: 1. The instrument installation adopts flange connection, screw connection and clamping type; 2. The direction of liquid flow during installation should be consistent with the direction of the arrow on the sensor housing, and the upstream straight pipe section It should be ≥6DS, and the downstream straight pipe section should be ≥5DS (DS is the measured inner diameter of the pipe under test). 3. The sensor should be kept away from the external magnetic field. If it is unavoidable, necessary measures should be taken; 4. In order to prevent the normal transportation of liquid during maintenance, bypass pipes should be installed outside the straight pipe sections at both ends of the sensor; 5. When the sensor is installed in the open air , Please do a good waterproof treatment of the amplifier plug; 6, the sensor and display instrument wiring, should be based on the power supply of the amplifier to select the wiring method, see the relevant "instruction manual".
7. Model and specification of turbine flowmeter:
LW X X- XXX XX
LW stands for turbine flow sensor;
XX: GY means remote transmission display type;
Y indicates on-site display type;
GB means transmitter;
XXX: indicates the caliber of the turbine flow sensor;
XX: B means explosion-proof type; E means clip-on type;
Such as: LWGY-50-BE: indicates that the caliber is 50mm, explosion-proof, clip-on turbine flow sensor;
LWGB-50: Means 50mm, turbine flow transmitter.
The liquid turbine flowmeter transmitter is a high-accuracy flow transmitter. It is used in conjunction with corresponding flow indicators and accumulation instruments to measure the instantaneous flow and total flow of clean liquids. It is widely used in chemical industry, light industry, etc. department. When the measured liquid passes the sensor, the turbine is driven to rotate. Because the spiral turbine is made of magnetically permeable material, the magnetic flux of the coil is periodically increased or decreased after the rotation, and the pulsed electric current whose frequency is proportional to the flow is induced by the coil signal. This electrical signal is weak (about 20mV ~ 500mV), it needs to be amplified by the pre-amplifier (the amplification factor is about 400), and then sent to the flow indicator and accumulation instrument for processing. The sensor consists of a mechanical device (turbine, deflector, housing, etc.) and an electronic device (preamplifier). The preamplifier is installed in the upper part of the housing, and the two devices are connected by a screw.
传感器按不同的工作要求，往往会安装在距地面较高的管道上，检查和拆修较困难。 Turbine flowmeter sensors are often installed on pipes higher than the ground according to different work requirements, making inspection and repair difficult. When the sensor has an abnormal situation, although the indication and accumulation instrument are normal at this time (general indication, the accumulation instrument is installed in the control room far from the transmitter), there is still no indication and flow accumulation. At this time, you can take a simple method to quickly check the sensor and troubleshoot in time. The method is: first unscrew the preamp from the housing to separate it from the housing, and then use a screwdriver to continuously touch the bottom surface of the core where the coil L is located (the bottom surface near the turbine). At this time, the following conditions must be met: One of them appears: 1. The display meter has an indication, and the cumulative meter has a digital accumulation, which indicates that the sensor is working normally. 2. There is no digital accumulation of the accumulated flow, which indicates that the sensor is faulty. The reason is that when the iron core of the coil L is touched with a screwdriver, it actually simulates the situation when the medium passes through the sensor, which changes the magnetic flux passing through the coil L, thereby generating a pulsed electrical signal, which is amplified by the preamplifier and sent. Enter the instructions, accumulate the meter to make it work. If the speed at which the screwdriver touches the L iron core of the coil increases, the accumulating speed of the accumulated meter numbers will also increase. When the core of the coil is touched, and there is no digital accumulation in the accumulator, the coil can be checked with emphasis. Because the coil has many turns and the wire diameter is small, it is easy to break the circuit and cause no pulse electric signal. At this time, it can be replaced according to the original specifications or re-wound according to the original wire diameter and turns. Another situation is that when the iron core of the coil is touched, the accumulation meter has a digital accumulation, which has shown that the sensor is normal, but the actual operation (medium through the transmitter) has no digital accumulation, which is possible in the sensor. The turbine is blocked by foreign matter and cannot rotate or becomes too slow. At this time, only the inside of the casing needs to be cleaned to ensure that the turbine can rotate normally. In fact, there will still be a small amount of impurities in the clean medium. To ensure that the sensor can work normally for a long time, you can install a filter with the same diameter on the front of the sensor to block the impurities in the medium and make them filtered. It will not affect the normal rotation of the turbine.