NOV Mono provides offshore sewage handling solution

Three TR Munchers and three Compact C range pumps from NOV Mono have been chosen for a demanding sewage handling operation in the Caspian Sea. They will be used to macerate and pump black water on a deepwater semi-submersible drilling rig which is located there.

The equipment has been selected by Wärtsilä Water Systems of Poole, England, which provides products and solutions for offshore facilities used in oil and gas exploration, development and production, as well as marine vessels. The company’s projects manager, Jeremy Freeman, said the equipment would “have to withstand some extremely harsh offshore conditions and comply with environmental legislation”.

“We know Mono’s equipment very well, and we would always consider it for a project of this kind,” Freeman continued. “We also receive very proactive support from Mono, and this was another factor in our decision. Rather than just supplying pumps, they look carefully at each specific application and suggest the most appropriate solution that will deliver the performance that’s required.”

The Mono TR Munchers will be used to macerate the black and grey water produced on the platform at a capacity of 8.8 m³/h. They are designed for the efficient maceration of abrasive sludges and are effective in capturing irregular-shaped objects, due to their layback cutter shafts which are set at an angle to the incoming flow. The shafts operate at different speeds to tear apart any solids, while a cantilever shaft design reduces the number of wearing components by eliminating the need for bottom bearings and seals.

The Muncher also features Mono’s EZstrip technology, which allows the unit to be maintained in place, reducing the maintenance time required and maximising availability. Any rejected objects are allowed to fall into an easy-access waste trap that is set below the cutter stacks to prevent damage. Munchers can be supplied to comply with the ATEX Directive 94/9/EC for this type of hazardous area application.

The three Mono Compact C Range progressing cavity pumps, which operate with a Wärtsilä Water Systems membrane bioreactor, provide a fluid transfer solution that will fit into the compact space of the platform, yet still perform reliably and efficiently at 2 bar pressure. Available in cast iron or stainless steel, and with a choice of rotor and stator materials for different applications, the high-pressure pumps eliminate the need for a series of pumps when pumping over long distances or with high head requirements. As with the TR Muncher, pumps can be supplied to comply with the ATEX Directive 94/9/EC.