Choice of protection level
The protection level of the electromagnetic flowmeter should be selected according to the actual situation. If the sensor is required to be installed below the ground and is often flooded, IP68 should be selected. If the sensor is installed above the ground, IP65 and IP67 should be selected. In any case, the display area of ??the electromagnetic flowmeter cannot be used with water or enter the water, which may cause damage to the electromagnetic flowmeter. As a chemical company, the workshop produces high humidity, but IP65 (IP65 is a water-proof type. The electromagnetic flowmeter sensor housing allows the faucet to spray water from the sensor in any direction of the sensor of the electromagnetic flowmeter. The pressure of the water spray is 30Kpa, the water output It is 12.5L/S and the distance is 3 meters.) The electromagnetic flowmeter of the protection grade fully meets the requirements of on-site measurement.
Choice of connection method
Electromagnetic flowmeters have threaded connections, flanged connections, clamps, etc. In the chemical industry, flange-connected electromagnetic flowmeters are generally used. The selection must be consistent with the process-flange engineering pressure and standards.
Conclusion, with the maturity of the domestic instrument industry, chemical companies such as lithium carbonate, boric acid and potash will also enter the market in line with the domestic market. As an important industrial flow measuring instrument, electromagnetic flowmeter should play its role in DCS control. The right selection is especially important to provide accurate measurement data, reduce labor costs and increase production efficiency.
Steam vortex flowmeter measurement requirements
Keywords: steam vortex flowmeter, saturated steam vortex flowmeter, superheated steam vortex flowmeter
What should I pay attention to when measuring vortex flowmeter? What is the best way to measure steam installation by vortex flowmeter? Can vortex flowmeters be used for steam metering? The vortex flowmeters are evaluated for their measurement performance under single-phase flow conditions. There is currently no single-phase flowmeter for measuring the system variation of two-phase flow. However, the two-phase flow exists objectively, and its influence on flow measurement is unavoidable. Despite the difficulties, people are still trying to study the mechanism of its influence on flow measurement, and take corresponding countermeasures to improve the accuracy of flow measurement.
First, steam flow measurement difficulties
During long-distance transportation, dry steam will partially condense due to heat loss, resulting in reduced steam dryness and become wet steam. The gas-liquid two-phase flow structure in the horizontal pipe is related to the gas-liquid two-phase volume ratio and the flow velocity. In the steam pipe, since the volume ratio of the condensed water in the wet steam is small, the drain pipe drawn from the bottom of the horizontal pipe is made. , can receive a good hydrophobic effect. When the flow rate is particularly high, it will also behave as a circular flow, that is, there is a liquid film on the pipe wall, and the central part of the pipe is a gas core with droplets. Due to the influence of gravity during horizontal flow, the lower liquid film is higher than the upper pipe. The thickness of the wall, in the vertical ascending pipeline, the basic structure of the gas-liquid two-phase flow has a fine bubble flow structure, a bullet-like flow structure, a block flow structure, a ring-shaped flow structure with fibers, and an annular flow structure.
Selection of measurement types for special industrial and commercial users
2. Case 2: A heavy machine tool factory
The main gas plant of the heavy-duty machine tool factory is 13 production kiln, and there is also a machine repair workshop and 63 mobile burners. The total gas load of all gas facilities is 1837m3/h. See Table 1 for details. The customer promised that all gas facilities could not be fully activated at the same time, the maximum gas consumption required was 1200m3/h, and the minimum pressure required before the furnace was 0.055MPa. The pressure regulator used in the on-site pressure regulating metering box is opened and ready, and the flow meter is in the form of a G1600 turbine table plus bypass.
When debugging the kiln, it was found that the flowmeter in the pressure regulating metering box had a stop-and-go phenomenon. If only some of the kiln was opened or only some of the kiln was used, there would be a phenomenon that the flowmeter did not measure or the measurement error was large.