Waste disposal costs have always been a necessary evil for food processing plants, but the situation is set to get tougher with an ever increasing landfill tax, stricter regulations covering the disposal of animal by-products, and the stringent penalties they carry.

Manchester manufacturer, Mono Pumps, has supplied equipment to food processing plants for many years, and has become increasingly aware of the costly issues surrounding waste handling and disposal in the industry.  The company has researched the technical problems facing waste handlers and determined how progressing cavity pumps and grinders - designed to handle biodegradable waste - can provide effective solutions.

Mono discovered that the need  for food processors to comply with legislation and reduce waste disposal costs is prompting many processing plants to replace their labour intensive and ineffective waste handling methods, with low maintenance, environmentally friendly alternatives, enabling  cost effective waste handling and disposal. Cost reduction across the whole waste handling process, improved hygiene, and  the reduction of unpleasant odours when moving waste products across site are also becoming priorities for food manufacturers and processors. 

Independent research suggested that the majority of food processing plants in the UK currently pay out far more than necessary on waste handling and disposal.  Mono Pumps business development manager, Ian Hallows, explains: “Simply by installing a macerator to effectively reduce the solids size of various on-site waste material, most of the plants we visit could reduce their volume of waste by up to 40%, thereby substantially reducing transport and collection costs.

“Maceration also improves the  homogeneous consistency of biodegradable waste, making it far simpler to recycle, re-use as agricultural fertilizer, or employ as a means for producing methane gas in a digester, which in turn can be utilised as a valuable fuel on site.”

Waste Reduction

Biodegradable waste is fed into a  grinder via a hopper to pass through a series of cutters, which revolve at differential speeds to pull apart, crop and shear any solids, such as bones, feathers, offal and vegetable waste. Liquid passes through the cutter stacks, whilst the solids are trapped and  ground to a small, consistent particle size, to help comply with animal by-product legislation and improve process efficiency. 

A heavy duty macerator such as the Series F Muncher® can grind up to 10 tonnes of bulky waste product per hour, breaking it down into small particles. Ian Hallows comments: “It can  process whole ‘off field’ products such as lettuces and cabbages in a matter of seconds, and make easy work of large cylindrical produce, such as coconuts and melons, which are often considered problematical to dispose of.  When extra fine maceration is required for recycling purposes, the waste can be fed through a secondary  grinder – such as a Mono TR Muncher® – to break it down into 3mm particles.”

Waste Transfer  

Already well-proven in food production processes and many mainstream waste and sewerage applications, progressing cavity pumps are increasingly finding their way into processes where waste material from food production must be moved and disposed of quickly, efficiently and reliably, reducing the need for manual waste handling.

Progressing cavity pumps have a unique ability to handle hard, angular and abrasive solids, such as crunched up carcasses and bones.  They provide outstanding performance with highly viscous, fatty or greasy materials, and their low maintenance ensures huge advantages in terms of whole life operational costs. 

The Widethroat W Range of positive displacement pumps is ideal for use with bulky materials, such as animal by-products, brewery and fruit and vegetable waste.  The rotary action generates pressure at any speed and does not require centrifugal force or high rotational speeds to operate effectively. This also eliminates large changes in the velocity of the pumped material, minimises any agitation and turbulence and provides a consistent flow.

3 step solution

Food processors are typically looking at a 3 stage solution to reduce manual handling, enable recycling and speed the whole process: a preliminary  grinder to break the waste down into a manageable size, a progressing cavity pump to transport the waste across site, and a secondary  grinder to  produce finer pieces.

Animal by-product regulations and rising disposal costs led Scottish tannery W J & W Langs to install a Mono Muncher® at its plant in Paisley to reduce bulk waste and improve the efficiency of composting as an alternative to landfill.

Each month the tannery produces approximately 500 tonnes of fleshings - a bulky waste product stripped from the hides prior to tanning.  More stringent restrictions on disposal led the tannery management to look for a better way of dealing with the waste, and so they turned to Mono’s Scottish distributor, Clyde Associated Engineers, who had previously helped this customer to improve their waste handling on site.

Eight years ago a Mono W Range widethroat pump was installed to pump tannery waste 30 metres directly to a waste disposal area, creating a more hygienic and enclosed waste disposal system.   The W range pump removed the need for manual handling of the fleshings and replaced the constant 30-minute cycle of filling and fork-lifting away skips full of the material. 

A Series A Muncher® has now been installed on the vertical pipeline of the pump discharge to process the waste fleshings.  The fleshings are macerated to a small particle size to assist the biological breakdown of the material, and collected by a waste management company and composted for use as top soil for extinct landfill sites, or as fertilizer.

Tannery engineering manager William Alexander is delighted with the efficiency of the new process.  He explains: “The cost of waste disposal has been substantially reduced by macerating the fleshings and sending them on for composting, but the benefits are more than just monetary. The process is far more efficient, easy to maintain, and has resulted in a safer working environment.”

The need to act now

Expectations of waste disposal are changing, and manufacturers need to start looking seriously at how they handle and dispose of their waste now, to ensure they comply with legislation. With its  knowledge of the food and waste industry, and valuable years of experience as a leading equipment manufacturer, Mono is  equipped to deliver low maintenance and cost effective grinding and pumping solutions designed to effectively handle biodegradable waste, reducing bulk and making it easier to recycle.

To arrange for a Mono bulk waste reduction survey please call Mono on 0161 214 2267.