Measurement of Abrasive Fluids for Flocculent Dosing
Application Report | Metal & Mining
- Concentration measurement of abrasive slurry in sand production
- Improved measurement accuracy gives savings on expensive chemicals
Rådasand AB is a Swedish producer and supplier of fine sand to various industries including concrete, filtration manufacture, etc. The fine sand is gained from sand/clay slurry which is the raw material for the process.
To be able to get the fine sand out of the water, they have to add the right amount of flocculent chemicals to settle the sand. Therefore, Rådasand required an accurate measurement of the mass concentration of the sand mixture to provide an input to the controller which governs the ratio of flocculent addition to the mixture. The mass concentration controls the whole process in a ratio with the volume flow measurement of the highly abrasive slurry.
- Process Parameters
- Media: Sand/Clay slurry (< 10 % Sand, > 90 % Water)
- Pressure: 2 bar (29 psi)
- Temperature: 15 °C (Ambient) (59° F)
- Flow capacity: 15000l/h (3963 gal/h)
- Sand content: 800 kg/h (1763 lbs/h)
For a direct mass concentration measurement, KROHNE suggested a Coriolis mass flowmeter. The only equipment suitable for the application was the OPTIMASS 7000 series due to its single straight tube, which is less susceptible to abrasion in comparison to a double straight or bent tube meter. In addition, the delivered DN 40 (1 1/2‘’) meter featured a measuring tube made of Titanium.
With this measurement solution, Rådasand was able to reduce the dosing of the high-priced flocculent (inorganic coagulant) and save costs due to improved accuracy. Furthermore, the improved efficiency in the process resulted in a better end product. Pressure drops were reduced due to the single straight tube meter and its design also allows for a high durability and long lifespan even with the abrasive medium.