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UK POWER & PROCESS ENGINEERING (issue 3) 2008

Our solution: Baviera Condensation Recovery Unit (CRU)
Site: Norwich, England
Energy type: Natural Gas
Date: Early 2008
Result: 22% savings in Gas consumption and 74% savings in Water consumption

Steam is used across a vast range of manufacturing processes, and the production of steam consumes a great deal of energy. Traditionally, steam is simply released into the atmosphere once it has been used, together with its precious heat energy. However, with the inexorable rise in energy costs and with water's migration from a cheap, disposable commodity to an increasingly expensive resource, this waste is becoming less and less acceptable.

Smurfit Kappa UK (SKG) is one of the country's leading manufacturers of corrugated packaging, and also operates a successful recycling division complete with paper mills. Their plant at Norwich produces packaging and specialises in high quality 'microfluted' cardboard used for retail and marketing display purposes. The company has a clear environmental policy, and one of the stated aims is to 'make efficient use of energy and convert wastes to energy whenever possible'. It is with this background in mind that the Enersol Corporation proposed a solution.

The steam production process means that condensate at high temperature is returned to the boiler 'make-up' tank and the greater part of the heat energy contained is simply wasted by being released into the atmosphere. The energy taken to heat the water, together with the chemical treatments applied to ensure the water is suitable for production purposes is similarly wasted.

Enersol proposed a Condensate Recovery Unit (CRU) which interrupts this waste process by capturing the condensate and pumping it back into the boiler, thereby feeding the boiler with clean, treated hot water that requires less energy to bring it to process operational temperatures. On start-up, the system is automatically bypassed until a set point is reached. This is identified by a temperature and pressure sensor in the system, which returns the condensate once the return temperature reaches the set point of 130°C. The specially designed KSB pump has a mechanical seal which is cooled both by passing water over it and with airflow from the pump motor. This means that the mechanical seal operates at between 60 & 70°C even though the pump is operating with water temperatures of 180°C.

Where temperature or pressure control is required, steam pumps are utilised. These have no moving parts and are controlled by level sensors. The outputs are monitored via a panel which clearly shows the operation of the pumping system. As with the CRU, the steam pumps are bypassed until the pre-set operational pressure is reached.

The system has been developed by Baviera of Spain, and the consultancy and project management was conducted by Enersol Flomar, the Enersol Corporation's steam systems division based in Fleckney, near Leicester. Enersol Flomar are Baviera's exclusive representatives for the UK and Ireland. Installation was carried out over two weekends with one week of normal running between. There was no loss of production. After two months of operation, the system achieved outstanding savings with an energy (natural gas) saving of 22%, and a 74% saving in water.

On similar continued performance, the investment will be returned in significantly less than a year. This success has led to more plants placing orders to reduce operating costs.

SKG Engineering Manager David Wilde stated that he is 'delighted' with the total project and has not had to touch the system since the day it was commissioned.