Installation of turbo flowmeter
In order to give full play to the characteristics of the turbine flowmeter, the flowmeter installation must also be used to pay full attention. The following is an overview of this issue.
(1) measured medium
Turbine flowmeter measured liquid, generally low viscosity (generally should be less than 15 × l0-6m2 / s), low corrosive liquid. Although there are already used for a variety of media measurement of the turbine flowmeter, but the high temperature, high viscosity, strong corrosive media measurement still need to carefully consider, take appropriate measures. When the medium viscosity v is greater than 15 × l0-6m2 / s, the flow meter meter coefficient must be real liquid calibration, otherwise it will produce a larger error.
Vapor-liquid two-phase flow, gas-solid two-phase flow, concentrated-solid two-phase flow can not be measured with a turbine flowmeter.
(2) Installation piping requirements
The installation of the flowmeter has a great influence on the measurement accuracy of the flowmeter.
The uneven distribution of flow velocity and the presence of secondary flow in the tube are important factors influencing the measurement accuracy of turbine flowmeter. Therefore, the turbine flowmeter on the upper and lower straight pipe section has - set requirements. For industrial measurement, the general requirements of the upstream 10D, downstream 5D straight pipe length. To eliminate the secondary flow, it is best to install the rectifier at the upstream end. If the upstream side can ensure that there are about 10D straight pipe, and install the rectifier, the flowmeter measurement accuracy can be achieved when the accuracy of calibration level.
② Turbine flowmeter on the cleanliness of the fluid have higher requirements, in the flowmeter must be installed before the filter to ensure that the fluid clean. Filter can be used funnel type, its own cleanliness, can be measured at both ends of the differential pressure change.
③ To ensure that the liquid through the flow meter is a single phase, that is, can not let air or steam into the flow meter, upstream of the flowmeter should be installed when the gasifier. For easy to vaporize the liquid, downstream of the flowmeter must ensure a certain back pressure. The size of the back pressure is at least twice the pressure drop of the flow sensor at the maximum flow rate plus 1.2 times the maximum vapor pressure at the highest temperature.