Steam vortex flowmeter flow range and upper limit flow, application range

Posted by hw on May 26th, 2021

The upper limit flow of the vortex flow meter refers to the full range of flow. The diameter of the steam flowmeter should be selected according to the flow range of the pipe to be tested, and the upper limit flow and lower limit flow of the selected instrument are selected, not the simple selection according to the size of the connection.

The maximum flow rate of the pipe fluid is usually designed to be determined by the economic flow rate. Since the traffic is too low, the pipe diameter is large, the investment is large, the traffic is too high, the transmission power is large, and the operating cost is increased.

The upper limit flow of most mass flow meters is close or slightly higher than the economic flow of the pipeline. Therefore, the selected instrument has the same probability as the diameter of the pipe diameter, and is convenient to install. Even if the diameters are different, there is no difference between them. Typically, the neighboring single size specification can be selected. In this case, a different diameter pipe connection should be used.

Some instrument traffic upper limit (or lower limits) cannot be changed after it is determined. Some instruments can be recalibrated by the user without actual traffic calibration. After designing the differential pressure gauge, the lower limit flow cannot be changed, but the upper limit flow can be adjusted by adjusting the differential pressure transmitter range.

What is the range?

The so-called range is the ratio of the upper limit flow and the lower limit flow, the greater the value, the wider the flow range. Linear instruments have a wide range, nonlinear instruments have a small range, which can meet energy saving and commercial accounting accumulation flow measurements. However, in some cases, the tools of business accounting have a wide range of tools.

If you use a differential pressure, you cannot adjust it. However, in recent years, various differential pressure gauges have been broken, mainly applied to differential pressure transmitters and microcomputer technology, but their prices have doubled.

In some turbine flow meter manufacturers, the upper limit flow has a high range and does not use high flow rates. The key is whether the lower limit flow is suitable for measurement requirements. Typically, when this range is required, the lower limit flow rate is preferably as low as possible.

Application range of vortex flow meter different media

The vortex flowmeter can accurately measure the flow of liquids, gases, and steam. In actual work, due to various external reasons, the medium is not pure, the liquid and gas are so simple, which will be unfavorable due to various factors. The flow measurement of the instrument (such as water-containing steam affects the accuracy of the vortex flow gauge).

Below we will analyze possible factors in detail.

1. When the fluid contains a solid

When the fluid contains a smiling solid particles, the fluid flowing through the instrument conduit will cause the vortex generator and the sensor to be cleaned, and the noise generated by the flow signal is irrelevant. Wear eddy current generator and instrument factor affect the measurement error of the instrument. When this happens, consider install the filter or periodically test meter upstream. If the fluid contains fibers, avoid filament winding vortex generators or sensors;

2. Fluid that is easy to precipitate or fouling

When measuring the flow rate of such fluids, the eddy current generator should be prevented from covering the surface due to long-term deposits or scale, affecting the shape and size of the vortex generator, thereby changing the flow meter factor, resulting in reduced flow rate. Sensor sensitivity. , Requires regular cleaning tools;

3. Mixed phase fluid

1. Our vortex flow meter can measure fluid containing uniformly dispersed minute bubbles, but must ensure that the volume gas content between the gas and the liquid two phase flow should be less than 70. If it exceeds 2, a metering coefficient correction is required;

2, can measure uniformly distributed solid micromaterials, but the content must be less than 2AS-solid, liquid solid two-phase flow;

3, can measure the two components (such as oil and water) that can be measured, but must be guaranteed that the flow rate is greater than 5m / s, otherwise the accuracy can be affected.

4, fluid contain pulse flow

When the power machine such as a blower or a water pump is installed in the mounting tube of the vortex flowmeter, a strong pulsation flow will be produced in the fluid. If the pulsation frequency is within the signal frequency of the vortex, it will occur seriously. It may result in the formation of the card gate vortex.