DEA
Engineering Company |
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| Phone:(951) 552-0102 | Fax:(951) 763-1263 | E-mail: dealigio@deaengineering.com |
Mechanical Installation & Operating Considerations
Electronic Installation & Operating Considerations
APPLICATION
DATA SHEET 40520
DEA Positive Displacement Microflowmeters are generally limited to direct measurement usage in relatively clean, low viscosity liquid applications. If the fluid to be metered is other than this, an alternative, inferential method utilizing a barrier is recommended. The barrier is in the form of a fluid driven positive displacement pump.
Shown below are two diaphragm pumps. They are selected for purposes of simplicity and, generally, economics. Piston pumps would work as well. These pumps are normally driven by compressed air. In the alternative recommended, herein, hydraulic pressure replaces the compressed air as the motive force in the primary pump. A secondary pump is employed to provide this hydraulic pressure.
The primary pump displaces the high viscosity, unclean liquid or slurry to meet system requirements. The secondary pump displaces a clean, low viscosity liquid, such as, isopropyl alcohol. A DEA Microflowmeter is installed between the secondary and primary pumps to measure the flow of the benign liquid. Every displaced unit volume from the secondary pump will displace an equal amount in the primary pump. Including any reasonable discrepancies due to fluid compressibilities, elastomeric moduli, hysteresis, etc., the accuracy of such an approach should be well within ± 3 %. Repeatability should be substantially better than that.
Flow control
can be effected by down stream process system throttling, pressure control
to the secondary pump or through a closed loop feedback control system
controlling the flow through the Microflowmeter.
| Flowmetering of High Viscosity Fluids |
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