process heating for the future

When 2K Manufacturing developed a pioneering new plastic recycling method, it required equally ground breaking engineering solutions to make the process work efficiently, smoothly and safely.  Working with industrial process heating specialist Babcock Wanson UK, an innovative thermal fluid based heating and cooling system was designed and manufactured that could work effectively at the upper  and lower ends of the heating cycle, yet remain efficient and simple to operate.

The world is littered with waste plastics.  The UK alone uses over 5 million tonnes of plastic per annum, with just 20-25% recovered or recycled.  The vast majority of this recycling figure applies to thermoplastics which can be repeatedly melted down and re used.  Thermosets such as Polymers and Epoxy based plastics, on the other hand, cannot be separated back into their constituent elements once cured and continue to head for landfill. 

Clearly bad for the environment, landfill is also bad for business as landfill costs continue to rise, along with taxes on waste.  ‘Going green’ is no longer a vaguely pleasant concept, but has genuine financial benefits and, for the construction industry that generates about one third of all landfill, is an increasingly important factor in winning construction tenders.

2K Manufacturing was formed in January 2007 to manufacture industrial products from recovered waste plastics and has since developed the ground breaking technology - Powder Impression Moulding (PIM) - which takes unwanted co-mingled polymer waste and re-manufactures it into high-performance, environmentally sustainable EcoSheet panels.

EcoSheet panels are hard-wearing, smooth-faced, versatile 8’x4’ boards suitable for a variety of applications in construction and beyond.  EcoSheet is engineered to perform as an alternative to imported plywood or to virgin plastic panels, yet in turn is fully recyclable at end-of-life.  In fact, 2K claims EcoSheet is not just an environmentally friendly alternative to plywood but is actually a superior product as it has similar technical properties to plywood, but is rot proof, easy to cut on site with no splintering or dust, holds paint longer and more evenly and can be readily fixed with screws.

As you might expect, it’s slightly dearer than plywood for the initial outlay (about 10%), but life time costs more than make up for that as the product’s durability means it has a considerably longer life span and can be recycled again and again.  And again for that matter!

EcoSheet has certainly generated a huge amount of interest amongst environmentalists and the building and construction industry at large and has won a number of awards for its innovation and sustainability.  But the patented Powder Impression Moulding technology is still in its infancy and faces all the challenges that go with developing a completely new process.  Developing close working relationships with engineering and technology providers has therefore been a key strategy for 2K Manufacturing.

Babcock Wanson UK is one such partner that has worked with 2K from its inception.  Chris Horsley, Managing Director of Babcock Wanson UK, explains: “we were introduced to 2K in 2007 and worked together to develop an indirect heating and cooling system for the moulds.  Planning was key here and, I’m pleased to say, the original plan is very similar to the finished process, although the Luton based factory is a quite a bit larger than the original concept.  It’s been very much a process of evolution, not revolution”.

Babcock Wanson designed and built the entire heating and cooling process to operate the Powder Impression Moulding system based around its EPC2000 ES Thermal Fluid Heater.  The production process is fed with pulverised waste mixed plastics and requires heating following a fixed profile to melt the plastic, held at a close control temperature for a period and then cooled at a fixed profile to ensure a perfect product.  “With that amount of temperature change in a very short cycle,” states Chris, “you are limited in what you can use – steam or high pressure hot water are just not ideal to achieve such temperatures.”

Instead, the EPC2000 ES Thermal Fluid Heater with integral exhaust gas to combustion air recuperator was selected due to its high overall operating efficiency and total output easily meeting the process demand.  A vertical fired heater, the EPC2000 ES is constructed from continuous concentric coils with flame reversal combustion chamber and three gas passes.  Its double combustion air preheating provides high combustion efficiency of up to 92% whilst its complete insulation of the external shell ensures minimal heat loss. 

The thermal fluid system has been designed with a separate cooling circuit (although using the same fluid) using air blast coolers, each fitted with two axial cooling fans to provide the cooling load. 

Ten independent Temperature Control Units have been connected to the heating and cooling distribution mains to automatically feed the hot and cold fluid to the production line, meaning that each part of the line can be at a different part of the thermal cycle at any given time; a key factor for the flow line production system needed by 2K.

The EPC2000 ES and cooling system currently operates one production line but has capacity for a second. Eventually further production can be added with additional heating and cooling capacity being simply added as production ramps up to meet demand.

One of the key challenges for Babcock Wanson in this installation was to source a single fluid capable of both heating and cooling the moulds.  “To reach these extremes of temperature whilst still maintaining good heat transfer properties and no pressurisation using just one heat transfer fluid was never going to be easy” claims Chris.  “We researched worldwide and used thermodynamic modelling to select suitable fluids.  Eventually we found a specialist fluid that was up to the job and it has performed extremely well.”

But for 2K Manufacturing and Babcock Wanson, this is an ongoing project to refine the process, to improve efficiency and reduce energy consumption.  Despite very good first results, neither company are resting on their laurels.  As a result, Babcock Wanson is looking to incorporate a heat exchange process into the design.  This is likely to involve an intermediary fluid loop which is run through the production line at key points in the cycle.   This system will transfer energy between computer selected points, therefore giving a head start to the heating or cooling cycle and helping to reduce the energy consumption of the process by up to 40% according to initial calculations.

2K Manufacturing CEO Omer Kutluoglu explains further: “We very much see Babcock Wanson as a partner for all our process heating and cooling requirements and have worked closely with them to get this part of the process right and to build flexibility into the system.  So, for example, we can expand production using the existing system and we can use both bio diesel and natural gas as our primary fuel and are even looking at cryogenically frozen natural gas from landfill as a fuel.  We are also looking to invest in a heat exchange system to keep energy bills down.  All of this will allow us in time to expand both the existing factory and to open new sites. Babcock Wanson are a key development partner for us.”

And there is certainly a market for the product.  When the EcoSheet plant is running at full capacity it will produce up to 160,000 boards per annum.  But when you realise the UK buys up to 30 million sheets of plywood per year – all shipped from overseas, including Brazil, Africa, China and Russia, at considerable environmental cost – EcoSheet certainly has plenty of scope for expansion.

Babcock Wanson has been supplying products and services for boiler houses for over 50 years, from steam boilers, thermal fluid heaters, rapid steam generators and hot water boilers to VOC and odour treatment by thermal oxidation, water treatment or process air heating solutions.  For more information, please contact Babcock Wanson on 020 8953 7111 or info@babcock-wanson.co.uk or go to www.babcock-wanson.co.uk.

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