Determining the effect of a new type flow conditioner on the accuracy of flow measurement by experimental method to reduce the upstream distance in orifice flow meters

Orifice flow meters: They become the most preferred flow meters since they are of simple use, low budget, durable and can be used in many flow types (liquid, gas, liquid + gas etc.). However, their long pipe installation poses an obstacle for them to be used in the limited space flow systems. Long pipe can be greatly shortened by using flow conditioners as a solution. Although many flow conditioners have been developed, flow conditioners are still being investigated in terms of pressure loss and short flow distance. In this dissertation, multi-hole flow conditioning plates that have low pressure loss (1x7, 1x6x12) were analyzed empirically to ensure the high measurement accuracy. One 1x7 unchamfered plate and four chamfered plates (15o, 30o, 45o, 55o ) were manufactured in order to investigate the impact of hole chamfer angle on the pressure loss. Additionally, one 1x7 (Porosity Ratio=0.25) plate that has a bigger porosity ratio was also manufactured. One common 1x6x12 Laws plate was used for comparison purpose. In the experiment, the impacts of a conditioner plate positioned in D downstream of a ball valve on orifice flow meters were investigated at two downstream distances (2D and 3D). Orifice plate (β=0.346, 0.480) inserted in test pipe of 52 mm in diameter was tested in three different flow rate (1000, 1500, 2000L/h) and at two valve positions. As a result of the empirical data, flow rate measurement error and conditioner plate pressure losses were analyzed. According to analysis results, minimum pressure loss occurred at chamfer angles around 20o and the pressure loss was 30 % less when compared with the unchamfered plate. In reference to results, even though 1x6x12 plate showed a flow rate measurement error below 0.5% in 50 % open valve position in all flow tests, that error could increase 5-10 times when the valve position is 20 %. This showed that velocity profile of 1x6x12 plate is very sensitive to distortion level. 1x7 (porosity ratio=0.25) plate showed very low flow rate measurement error below 0.5 % only when it was in L1 position and when the β=0.48 plate was inserted. It was observed that it is a better flow conditioner when compared with 1x6x12 plate since it was affected from valve position less in L1 position in all flow tests. Although chamfered conditioner plates of 30o and 45o showed flow rate measurement error below 1 % in all flow tests when β=0.346 orifice plate was inserted in L2 position, 15o chamfered plate showed better flow conditioner quality with flow rate measurement error below 1 % in L2 position in all flow tests. Since15o chamfered plate was affected less from the position of valve when compared with 1x6x12 plate, it was understood within the scope of this study that it is a very good flow conditioner within overflow distance like L2=3D.