Vortex street flowmeter installation instructions
Stress type vortex flowmeter is a kind of speed meter, based on the of karman vortex street, using piezoelectric crystal test fluid through the pipe produced during the triangular prism of the vortex frequency, so as to measure the fluid flow, vortex flowmeters are widely used in petroleum, chemical industry, light industry, power, heating, etc.
Vortex street flowmeter has the following characteristics: 1, high measurement precision, wide range; 2, measuring medium widely, can measure liquid, gas and steam; 3, high working temperature, medium temperature can reach 350 ℃; 4, no moving parts, no wear and high reliability. 5, table body is made of stainless steel materials, corrosion resistance.
Vortex street flowmeter measurement principle: when the fluid medium in the pipeline through the spiral body occurs, due to the local velocity of accelerate production vortex phenomenon, the spiral into two columns appear alternately, the spiral column is become the karman vortex street. Vortex separation staggered, in the wake behind the cylinder pressure pulsation, in the back of the cylinder, adhere to the role of fluctuation pressure probe received the tiny, buried within the probe of the piezoelectric crystal will receive alternating stress effect and alternating charge signal generation. Adhere to the amplifier to the signal conversion, amplification, filter and the signal after plastic processing, the output frequency and voltage pulse signal frequency of vortex separation, or the transformation process output is proportional to the separation and vortex frequency current signal. Output meter each pulse or a certain amount of current will represent a certain volume of the current body. Over a period of time the output to the total number of pulses or electrical flow integration, will represent the time flow of fluid combined.
The release of the karman vortex street frequency and width of triangular prism size and speed of fluid flow, and has nothing to do with the medium parameters such as temperature, pressure.
Installation methods and steps:
A, select installation location: when choosing installation position, the following points should be paid attention to
1, the installation location try to choose in the absence of the location of the pipeline vibration or small vibration, vibration acceleration is not greater than 2 g, such as vibration requires the anti-vibration measures;
2, sensors, upstream and downstream straight pipe must have enough;
3, repair valve installed in the upstream of sensor and flow control valve installed in the downstream of the sensor;
4, try to choose the location of the ease of installation and maintenance;
5, should choose the location of the dry environment;
6, the sensor can be installed in horizontal pipe runs, can also be installed in vertical pipe runs. But when installed in vertical pipe runs, medium must flow from bottom to top.
7, sensor installation indoors as far as possible, must be waterproof should be paid attention to when outdoor, outside the amplifier cables should be bent into a U;
8, sensors, stay away from electrical noise, such as high power inverter, power transformer, electric motor and power wireless transceiver , etc.
Second, the installation notice:
A, flange and straight pipe welding, should remove sensor, not with the sensor welding.
B, sensor installation, should make to indicate the direction of flow and the pipe on the shell.
C, flange welding has been completed, the pipe to clean there shall not be welding slag and other sundry.
D, before the installation of sensor and flange groove must be put in good sealing washer.
Three, sensor debug:
Sensor has been set, generally do not need to be zero, but the working conditions of the scene changes, generally run found abnormal, should be according to the following method is zero.
Sensors through to power supply, full of medium in the process piping, close the sensor downstream flow regulating valve (unconditional clearance downstream flow regulating valve, also may be shut valve upstream repair), first the potentiometer SF (beside the terminal) counterclockwise to an end, the sensor for interference pulse output signal. And then slowly clockwise SF, until no output can, just open the valve instrument should work properly.
Four, troubleshooting:
Failure 1: with flow in pipes, sensor output or don't show: intelligent flow totalizer.especially
A, first determine the pipe flow, and the lower limit is greater than the measured flow sensor.
B, see if instrument internal wiring is wrong or disconnection: method is to look at lines or with a hammer hit pipeline or sticks to the integrating instrument to display frequency, see if there is a frequency display, if there is, according to the wiring is correct, no frequency shows that it could line is wrong, need to check the wiring.
C, judge amplifier: plate method is to amplify the probe line to be removed, to see if the sensor output, or whether there is intelligent flow totalizer.especially 50 hz frequency display, if not, then you need to change amplification board, if there is output, then seven normal method.
D, judge sensor: the method is to head two lead from amplification board removed, sensing head resistance between the two leads is measured with a multimeter and sensing head two lead resistance of casing, respectively, should be larger than 2 m Ω, otherwise you need to replace the sensor head.
E, if the sensor is no problem, then check whether the pressure transmitter and platinum thermal resistance is damaged, the pressure and temperature on first see totalizer.especially display is correct if no problem, can judge the damage of intelligent flow totalizer.especially.
Fault 2: no flow in the pipe, a sensor output or intelligent flow totalizer.especially display
A, see if sensor installation position of vibration is too large, if the vibration is too large, can consider to install the anti-vibration stents.
B, instrument bad earth introduce interference.
C, in setting to remove small signal excision.
D, other fault can contact with the company's technical team to solve the method.
Fault 3: the pipe flow is normal, the instrument shows flow oscillation is too big
A, incorrect or improper installation.
B, amplifier, triggering sensitivity or improper gain adjustment, need appropriate adjustments to dial the code switch.
HD - 1000 - b size is low display is SIKE series vortex flowmeter measurement and control technology co., LTD. One of the dedicated circuit, it USES MSP430 series chips and double row sections of LCD, password can be set to medium, so as to accurately measure the flow rate at the scene. Less of a complete set of display by the micro power amplification board (for any diameter vortex street) and display board two boards, the function of the amplifier board is general, namely through the thin code switch can match all kinds of diameter of gas, liquid. The role of the display board is complete set, calculation and display function.