Colcrete stuck on Krohne flowmeter

London -- Colcrete Eurodrill Ltd has standardised on installing an electromagnetic flowmeter from Krohne in its specialist pumping stations. The systems are used to inject grout underground to fill the gap between tunnel ring segments and the ground around them and to construct grout curtains.

Colcrete Eurodrill’s equipment is designed to ensure that a precise ratio of grout and additive are combined together so that the mixture will gel correctly. The mixing stations typically comprise an automated mixing system, fed by big bag discharge stations or silos. Mixed product then passes to agitated storage tanks that feed high-pressure injection pumps.

Pumps inject the grout mixture to its final destination via the Krohne’s Optiflux 5300 flowmeters at rates between 0.2 and 600 litres per minute and pressures ranging between 40 and 100bar, depending on the application.

The Optiflux electromagnetic flowmeters incorporate three levels of diagnostics and, claims Krohne, set new industry standards of metrological performance and accuracy. The units are designed to provide engineers with comprehensive data towards anticipating and rectifying potential problems before they affect production

Additives can simultaneously be added to 'gel' the grout mixture as it enters the ground and these are fed through separate Optiflux flowmeters. Precise application of the additives is essential to ensure that the grout recipe meets the correct specifications for its applications. As well as monitoring the flow rate of grout and additives, the Optiflux flowmeters provide an output feed to a datalogger which records detailed information for future use.

According to Krohne, Colcrete Eurodrill opted to standardise on the Optiflux 5300 because its ceramic lining provides high level of resistance to wear, particularly in high solid applications. The company, it adds, now has over 100 Optiflux flowmeters operating in equipment around the world.

“Our equipment is exported throughout the world for specialist grouting contracts and their reliable operation is essential,” said Mark Rex, general manager at Colcrete Eurodrill. “We have tried several makes of flowmeter over the years and we have chosen to standardise on Krohne’s Optiflux because it gives the reliability and accuracy we need.”