与管道内径不相匹配的时候，先找合适的管道，并对原管道进行合理的改造，如果改造比较麻烦时，可以在现场装上大小合适的接头作为过渡段，并保证有足够的直管段，这样就能使流速分布恢复到足够的正常状态，我们在平时生产V锥流量计的时候，必须知道现场管道具体规格或者是直管段的具体规格，以便我们在生产的时候尽量减少这些外部因素所带来的不必要的麻烦。 When the v-cone flowmeter does not match the inner diameter of the pipeline, first find a suitable pipeline and make a reasonable transformation of the original pipeline. If the transformation is more troublesome, you can install a suitable size connector on the site as a transition section and ensure that There are enough straight pipe sections, so that the flow velocity distribution can be restored to a sufficient normal state. When we usually produce V-cone flowmeters, we must know the specific specifications of the field pipe or the straight pipe section so that we can Minimize unnecessary trouble caused by these external factors. .
Wide range ratio: The range of the V-cone type flowmeter is much larger than that of other types of differential pressure flowmeters, which is 10: 1 under normal circumstances, and can be increased if necessary. When the Reynolds number is higher than 8000, the output signal is linear. If it is lower than 8000, it can be measured, but the output signal needs to be corrected according to the curve. Straight pipe section requirements are low: the Boer equation requires that the measured fluid is an ideal fluid, which is simply impossible in practical applications. In many cases, the fluid distribution is uneven, such as elbows, valves, shrinkage, expansion, pumps, Tee and so on, for other instruments, this is a difficult problem to solve. The V-cone flowmeter can evenly distribute the fluid under extremely harsh conditions. For example, there are single elbows and double elbows immediately upstream of the meter. After the cone “rectification”, the fluid distribution is more uniform to ensure that the meter can obtain under severe conditions. Higher measurement accuracy. Because the V-type flowmeter can evenly distribute the fluid curve, compared with other types of differential pressure flowmeters, the requirements for the upstream and downstream straight pipe sections are less. It is recommended to leave 0-3D straight pipe sections upstream during installation. , Leave a straight tube of 0-1D downstream. When the size of the user's pipeline is large, the price of the pipeline is high, or the straight pipe section is not enough, the V-cone flowmeter will be the best choice. In the past ten years, the test has been performed on a single bent pipe at 90 ° C or two double bent pipes that are not on a plane upstream of the V-type flowmeter. The test results show that the V-cone type flowmeter can be used next to it. There is an elbow or a double elbow that is not on the same plane without affecting the measurement accuracy. The boundary layer effect formed by the unique structure of the flow meter prevents the key parts of the throttle from being worn, so it can keep the geometric size unchanged for a long time, so it can work stably for a long time without calibration. The flow meter is a purely mechanical body, so it is resistant to high temperature, high pressure, corrosion and vibration.
等节流装置根据现场参数计算开孔直径的时候，会涉及到这么一个问题，就是差压变送器的最大差压值如何选取的问题？ Manufacturers of production throttling devices all know that when calculating the opening diameter based on field parameters for orifice devices such as orifice plate flow meters and V-cone flow meters , such a problem is related to the maximum differential pressure of the differential pressure transmitter. How to choose the value? How to choose the differential pressure value, and how big should I choose? It is related to many factors, such as uncertainty, straight forward and backward pipe sections, etc. Therefore, when calculating the opening diameter of orifice plate flowmeters and V-cone flowmeters, you must not blindly choose a large differential pressure, but comprehensive consideration Some related factors.
How to choose the differential pressure value in the design and calculation of V-cone flowmeter and orifice flowmeter
的直管段要求就比较低，即使短些的话，相比而言的话，也不存在了2.差压值大时，β值变小，推荐使用的最小雷诺数较小。 1. When the differential pressure value is large, the minimum straight pipe section required can be shorter. For this feature, for orifice plate flow meters, considering the economic factors in all aspects, the opening value with the largest differential pressure should be selected; and V The cone flowmeter is relatively better. If the on-site fluid is Newtonian fluid, the straight tube requirements of the V-cone flowmeter itself are relatively low. Even if it is shorter, in comparison, there is no 2. differential pressure value. When the value is larger, the β value becomes smaller, and the minimum recommended Reynolds number is smaller. In this case, the actual Reynolds number may be much larger than the recommended Reynolds number, so the flow coefficient becomes stable and the measurement accuracy is improved. 3. For a differential pressure transmitter, a large differential pressure is more stable than a small differential pressure. 4. The basics introduced above are all the advantages when the differential pressure is large, but many times, when they have reached a certain level, they will definitely bring certain disadvantages. Those who are familiar with the process technology of orifice plate flowmeters and V-cone flowmeters should know that when the differential pressure is too large, the direct consequence is that the openings become small, and the relative pressure loss is also large. The plate flow meter has a large pressure loss. If this is added, the cost caused by this pressure loss is considerable for the entire process system. Compared with the V-cone flow meter, it is slightly more moderate.