Oval Wheel Flow Meters - Flow Measurement of High Viscous Resins

Production processes in manufacturing of abrasives and superabrasives require precise dosage of even high viscous resins (e.g. 1500 cP). The adjacent application picture shows one dosing skid in such application.

Each skid comprises of the following components:

1. Main tank
2. Secondary tank with low level alarm, always ensuring enough products and no air in the circuit
3.  Manual valve to close the circuit
4. Peristaltic pump
5. Oval Wheel Flowmeter
6. Pressure Switch (safety against high pressure)
7. 3-way valve (for manual or automated operation)
8. Outlet pipes for manual product collection

Task

At higher viscosities and depending on temperature fluctuations, the peristaltic pump (positive displacement pump comprising of flexible tube and of roller(s) displacing the medium from one end of the flexible tube to the other) is not able to displace the medium completely. This means that some part of the medium flows back through the flowmeter resulting in error readings. In addition, the operating pressure developed by the small sized peristaltic pump is quite low.

Solution

Oval wheel flowmeters model DON can be provided with special cut rotors reducing the pressure drop by 50%. Choosing the optional Quad Hall Sensor Dual Pulse Output provides two out of phase pulse outputs „A” and „B”, so that net flow rate „A-B” may be computed correctly by the PLC. Net flow rate could also be computed using ZOK-Z3 electronic with a pulse discriminator in between. With these features, we are in a position to solve all problems associated with this application and conduct very fine dosing of resins, resulting in an improved repeatability and quality of the finished abrasives.