Submersible mixers deployable even in restricted area tanks
Semisubmersible mixer as supplied for the two Sedco Transocean drilling rigs.
ITT Flygt has recently supplied 14 electrical submersible mixers to Sedco Transocean for two semisubmersible drilling rigs currently operating in the UK Atlantic Margin. The company seems certain that business will continue to grow in the UK sector.
The high viscosity and gel properties of modern drilling muds increases the importance of ensuring that sedimentation is not allowed to occur in the tank. This requires the mud to be kept in motion continuously, but the irregular shape of many tanks can make this difficult and they may contain areas where circulation is restricted. Any part of a tank that is occupied by settled mud can be quantified in financial terms as it represents lost mud and storage volume with a correspondingly higher cost of mud transportation per gallon.
The ITT Flygt's submersible mud mixers have been designed to overcome any circulation problems through their ability to be located virtually anywhere inside a tank. The motor and propeller are integrated in a single compact unit which offers unlimited flexibility since each mixer can be positioned anywhere in the tank.
As a result, the mixer's energy is not dissipated against tank floors, baffles, or facing walls - which can be a problem with conventional mud-mixing systems. The flow can be steered so that it follows the shape of the tank. With correct positioning and sizing of the mixer, the entire contents of the tank can be set in motion to prevent solids from settling with a minimum power input.
Easy retrofit
The ITT mixer range extends from 1.9 kW to 30 kW. They can also be retrofitted to replace conventional mud-mixing systems, like mud guns, or installed in tanks that were never designed to accommodate mixers. The designer also gains further flexibility through being able to stack tanks as top access is not necessary. Access to a Flygt submersible mixer can be achieved through a small aperture through which it can be raised in a matter of minutes without having to empty the tank.
The efficiency of ITT Flygt's mixers is partly due to their robust construction and high performance and also to the investment that the company has made in defining the fluid dynamics of submersible mixing. With the help of PC-based sizing programs and a network of regional test laboratories, Flygt project engineers are able to work closely with customers to configure a mixing system that prevents sedimentation in any tank of any shape and size.
The company also makes a range of heavy duty pumps in a wide variety of materials to meet varied corrosion, abrasion, and temperature requirements. They are available in a range of models from portable 1.9 kW units delivering 150 l/min to mammoth 450 kW machines with capacities of up to 150,000 l/min.
For further information contact Magnus Hermansson, ITT Flygt. Tel: +46 8 475 6000/6714, Fax: +46 8 475 6900, Email: [email protected]
