Dec 01 2014

The structure and working principle of the meter

Rotor type water meter is a speed type water meter, water meter varieties in the world is the most used.

Turbine Woltman Type Water Meter

In the national standard, the definition of velocity meter for “installed in the closed pipe, consisting of a power element, a water meter and flow speed by directly makes its obtain movement”. When the water flow through the meter, driving the impeller (rotor or spiral wing) rotation, and flow rate and impeller flow speed is proportional to, because the section area of nozzle flow driving impeller for constant speed and flow is also proportional to the impeller. Through the linkage components on the impeller shaft is connected with a counting mechanism, make the counting mechanism (cumulative impeller rotor or spiral wing) rpm, so write down through the meter of water.

Rotor multi beam type water meter is composed of a case, Turbine Woltman Type Water Meter, table glass, sealing washers, a measuring mechanism, a counting mechanism and strainer etc.

Rotor type water meter gear box at the bottom of the general had about three of the fixed rib, its main function is to, when the water meter in the large flow operation, on the impeller rotation damping effect, to improve the water meter in the performance curve of large flow area. Because when very small flow through the meter, the flow rate is very low, the minimum kinetic energy flow, not enough to overcome the inertia of the impeller, impeller without rotation. The question slightly increase velocity, impeller is rotating, but cannot accurately measure the range of flow meter, so the minimum flow following a slow phenomenon. Then gradually increase velocity, water meter to the fast development trend, if there is no gear box on the bar to damping, this trend will continue until around 10% ~ 15% after partial fast (compared with rib damping), the performance curve will tend to smooth.

In recent years, the Woltman Type Bulk Cold(Hot) Water Meter  improved significantly, but part of the pipeline is also the existence of rust, flax, iron and sand and other impurities, these impurities with the flow meter inlet end to. In order to prevent impurities from entering the meter movement, causing water fault, so on the water inlet end are provided with filtering net. Is a bowl shaped strainer used, set outside in the impeller box, this structure the dirt holding capacity is bigger, and even blocked a part of mesh after measurement capability also less affected; the other is a barrel shaped filtering net is arranged on the water meter shell, water inlet side, effect than the bowl shaped strainer differential.

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