Summary
The reliability and versatility of the advanced echo processing technology in Pulsars non-contact ultrasonic range has been utilised at the Swansea Waste Water Treatment Works, in a 23m deep application where other manufacturers had failed to provide a reliable low level signal. In order to minimise problems, such as pump clogging, resulting from solids accumulations, a wet well cleaning cycle routine was designed into the pump cycle, requiring low level control below the pump heads. The Pulsar Ultra 3 and dB40 transducer now provide continuous and reliable low level measurement allowing the above routine to be included in the normal pump cycle.

Swansea Waste Water Treatment Works is the main works for the City of Swansea, with a capacity of 165,000 population quivalent. The treatment works includes a deodorisation plant to ensure there are no bad smells in the vicinity and ultraviolet disinfection of the treated effluent before it is discharged to the sea, making it one of the most technologically advanced sewerage works in Europe. The Swansea project has brought significant improvements to the bathing waters in Swansea Bay and along the Gower Coast. This is a “flagship” project for the Green Sea Initiative – a unique partnership of private, government and environmental groups. Langdon Road pumping station is 23m deep and houses six 250 kw variable and fixed speed pumps, each capable of delivering 650 litres/s. Existing ultrasonic level control systems were proving unreliable at low level, because they were not discriminating the liquid level against the competing echoes from other items in the well. The measurement problems were leading the operators to consider the introduction of pressure transducers. This was not the preferred option to solve this problem as it would involve a continuous regime of costly planned maintenance Swansea bay installed a Pulsar non-contacting ultrasonic level measurement system, combining the company's Ultra 3 control unit with the dB40 transducer effective over 40 metres. The compact and easily installed dB40 provided a strong and reliable signal, while Pulsar’s in-built DATEM echo analysis software overcame the challenge that all ultrasonic level control manufacturers were posed when confronted with modern wet well design: to recognise the true process level, while ignoring all other competing signals from pump heads, girders, pipe work and the like. Pulsar’s unique DATEM system excels by interrupting the echo profile to maintain the true process level all the way down to the empty level, and by partnering the dB40 transducer provides a formidable solution to the problem of very deep well control.