Elemental (pure) sulphur is a valuable by-product recovered during the refinement of oil and gas and is sold on to be used in the manufacture of many products including fertilisers, chemicals, pharmaceuticals, asphalt and concrete. The sulphur is extracted and transported around the processing plant in liquid form at a temperature of some 140C. However, sulphur only remains in its liquid state suitable for pumping within a narrow temperature band of approximately ±20C. At lower temperatures the liquid will start to revert to a solid and at higher temperatures its viscosity actually increases due to the formation of polymers, all of which creates unique challenges for sulphur pumps. To date, many sulphur pumps have been simple adaptions of VS4 vertical pumps or other standard designs but these have brought with them maintenance and reliability issues for operators.
Three years ago, Amarinth decided to draw on its extensive expertise in designing bespoke pumping solutions for the oil and gas industry and apply this knowledge to produce an API 610 VS4 vertical pump that could meet the challenges of reliably pumping molten sulphur. Amarinth first undertook a detailed study of existing sulphur pumps (usually simple adaptions of existing designs) and how they were used and maintained to determine where issues occurred. Users reported high incidents of bearing failures, shaft problems and having to run significantly shorter maintenance periods to try and minimize failures, all of which resulted in increased downtime for the plants.
To deliver a robust, reliable and easily maintainable pump, Amarinth then embarked on an 18 month design and test study resulting in a pump which includes:
- A new arrangement for the shaft bearings and lubrication film which reduces the previous bearing and shaft issues operators had reported.
- Redesigned jacket to maintain the temperature of the molten sulphur and hence its viscosity, reducing the solidification of the sulphur around the pump particularly when it’s lifted for maintenance.
- New design of impeller optimised for best efficiency for molten sulphur.
- Amarinth’s proven modular column design that enables the rapid production of bespoke pump lengths and greatly simplifies maintenance and removal of the pump.
- Improved access so that regular maintenance can be completed quickly and with less disruption to the associated pipework and plant.
Following three years and an investment of over £1M, Amarinth has now launched its new range of API 610 VS4 vertical sulphur pumps giving oil and gas operators for the first time a cost-effective, efficient and reliable pump for the transportation of molten sulphur from point of extraction to ongoing processing.
Oliver Brigginshaw, Managing Director of Amarinth, commented:
“We are delighted to add these sulphur pumps to our range of pumps for the oil and gas industry. Drawing on our many years of experience with vertical pumps it is the culmination of three years research and development by our team of dedicated engineers and we look forward to leveraging the technologies we have pioneered on this project into other products to deliver even more effective pumping solutions for other applications.”