越来越广泛地应用于工业生产中的各种流体介质的检测。 With the advancement and development of detection technology and manufacturing technology, pressure-sensitive strain gauge target flow meters are more and more widely used in the detection of various fluid media in industrial production. It has the characteristics of sturdy structure, small resistance drop, less leakage points than other flow meters, high measurement accuracy and sensitivity, and easy maintenance. The torch chemical plant has special process media and has high requirements for the reliability and leakage prevention of the flow meter. The plant used about 70 WFV series pipeline and plug-in target flow meters from the American Welkin Company in its expansion project in 2001. , Mainly used for the measurement of process media, water and steam and other media.
1 Causes of errors
During the commissioning of the new device in 2002, the author summarized the experience of using some target flowmeters. After the target type flowmeter is installed in accordance with the technical conditions, the target type flowmeter is calibrated according to the design requirements when it leaves the factory, and it is put into operation according to the operating steps. A small number of meters show a large error and some alarms show full scale. Disassembled at the site and verified by removing the weight and finding that the flowmeter is good. After analysis, the main reasons are as follows.
1 Some large debris in the fluid is wound on the target rod, and it is easy to indicate the full range under the state of flow. This phenomenon mainly exists in the measurement of circulating water, which is due to the direct extraction of river water without filtering.
2 Due to installation errors, the target plate of all plug-in target flowmeters cannot be guaranteed to be located in the center of the pipeline, nor can the target plate be completely perpendicular to the pipeline. Therefore, there is a difference between the operating conditions and the calibration conditions before leaving the factory, which causes a measurement error of the target flow meter.
In view of the above reasons, considering that the plant's flow measurement points are not bypassed to reduce leakage points and reduce investment, the plant has formulated the following solutions.
1 In order to prevent larger debris in the fluid from getting entangled with the target plate rod, a filter screen is installed at the pump outlet to filter out these larger debris.
的误差。 2 Use the comparison method to correct the error of the target flowmeter at the production site. The instrument used: a 4 and a half digital multimeter; a portable ultrasonic flowmeter; necessary wiring clamps and tools.
The specific operation steps are described below.
First install the portable ultrasonic flowmeter according to the requirements. Pay special attention to the electrodes installed, and calibrate and adjust the ultrasonic flowmeter. Then check the target flowmeter installed in place with a digital multimeter according to the calibration book provided by the factory to check and adjust the zero position, range, damping, etc., and finally set the work switch to the measurement position.
Application analysis of target flowmeter Anti-condensation in the petroleum industry-measurement of high viscosity fluids Application of target flowmeter First of all, I have to understand the characteristics of the measurement medium. First of all, we have to understand the characteristics of crude oil. Reynolds number, our products have superior performance in measuring crude oil. Firstly, no filter is needed, and the flow meter can pass impurities. Then it is not sensitive to the Reynolds number, as long as the fluid has flow, it can basically be measured. In addition, the integrated structure design is light and easy to install, the sensor and the housing can be quickly separated, and no moving parts are nearly maintenance-free. This is the real reason why more and more field personnel are gradually adopting target flow meters. For intermittent working conditions and the medium is easy to condense and block at low temperatures, a target type flow meter with a thermal insulation sandwich can be selected to eliminate solidification and crystallization of the medium in the pipeline or process insulation.
Application of anti-corrosion-acid-base target flowmeters in the chemical industry: in the most demanding and complex chemical sites, measuring liquids and gases with corrosive media such as acids and alkalis. Target flowmeters made of special materials After years of field use data, it shows that its stable measurement performance has been widely praised by customers. Metallurgical industry Application of maintenance-free high-precision gas measurement flowmeters such as coke oven gas, semi-water gas, blast furnace gas, etc. contain impurities such as tar, naphthalene, ammonia, sulfide, etc. The sticky corrosion characteristics make flow measurement difficult. The target flow meter uses a capacitive force sensor to measure the gas flow rate, which is an innovation in itself, which makes gas measurement very easy. Adhesive and perishable media adhered to the sensor will not affect the flow measurement performance. The anti-vibration-air volume target flowmeter in the power industry is used for primary air volume. In most cases, secondary air volume detection has a short straight pipe section, a large amount of fluid containing dust, and large vibration. The plug-in target type flowmeter has strong anti-impurity and anti-interference functions, and can work normally under strong vibration conditions. You no longer have to worry about selection difficulties. Application of target flowmeters in the water supply and drainage industry During the industrialized production process, a large number of applications are made to water resources. Target flowmeters have gained a portion of the market with their unique advantages.
The integrated design of the food and pharmaceutical industries, inductive measurement, coupled with the sensor not in contact with the medium, uses a fully welded form of the flowmeter housing without dead angles. 完全可满足卫生条件的要求 Whether it is high or low temperature, high viscosity or low viscosity, with impurities and corrosion, the target flow meter can fully meet the requirements of hygienic conditions