Process plant design and Mixer specialist, J R Boone Ltd, has recently completed one of its more difficult assignments - building to a strict specification, a 1,500-litre capacity horizontal helical blade mixer (HHBM) - and all done in double-quick time. 

Adams Foods, part of Kerrygold, chose the company to supply equipment for mixing milk powders with up to 35 per cent fat content and minor additives in batch sizes ranging from 400 litres to 1,500 litres, with bulk densities of up to 1,050kg/m3. J R Boone had previously developed a completely new short aspect ratio Ribbon Mixer (HHBM) by adopting a scientific approach to maximise mixing efficiency, with only four helical blades for any machine size. This combined with the company’s comprehensive knowledge - gained over 40 years supplying mixers to the food processing industries - provided machines with the versatility to mix powders, pastes and slurries with simplified cleaning and maintenance. The resulting wide range of mixers based on common design element could then be produced at a competitive price. This was the ideal starting point for the company to start developing a custom model to meet the specific requirements of Adams Foods. Boone’s managing director, Chris Boone, explains: “Adams wanted to retain their existing feed hoppers and their conveying and discharging systems, while at the same time increasing the mixing capacity from 1,200 litres with their old machine to 1,500. Because of all these factors, we could only work to the same limited height as the old machine.

So we took one of our 1,250 HHBM models and re-designed it into a U-trough. Which increased its capacity to 1,500 litres, and we gave it an ATEX rating to ensure that it complied with the EU directive on installation into an area where small amounts of sugar can create a potentially explosive atmosphere.” One of the main stipulations from Adams Foods was that the new mixer should not suffer the same irritating problems as the old one. 

The company wanted an end to sealing and maintenance difficulties, to troubles caused by pressurisation and occasional overfill, and to problems of re-starting when the machine had to be stopped with a full load on board.
Chris Boone says: ”We fitted air-purged, packed gland seals and wear sleeves to give long life and easy maintenance. And the mixer can be subjected to over-pressure and regular full-load starts without any problems - or leaks.” All this and our speedy installation too. “Our redesign took just a few days and we cut our manufacturing time to eight weeks,” adds Mr Boone. The new HHBM machines from J R Boone are nothing if adaptable. They can handle a large range of products from breakfast foods to molassed sugar, and from cake mixes to instant potato. Things like frozen foods, powdered drinks and dough for dog biscuits are also taken in their stride, and in a non-food context - the machines can tackle car body fillers, the formation of thick slurries and fine chemicals. Over at Adams Foods, John Vernon, the factory engineer is more than pleased. He said “from the first day in production to the present time, the mixer has exceeded all our expectations, greatly reducing maintenance and increasing productive time.”

John R Boone supplied a HHBM (Horizontal Helical Blade Mixer) to Adams Foods, increasing batch size, reducing maintenance costs and improving the productive time available for production. Cost-effective, reliable and flexible, test, design and manufacture took only a shade over eight weeks to complete.

John R Boone and GC Hahn – a great combination

Summary:

John R Boone Ltd worked closely with GC Hahn UK, a major manufacturer of food ingredients and additives, to design and install a mixing system to meet exacting standards of hygiene and to handle very demanding formulations. The end result has been a great success, mixing Hahn’s most difficult materials to high standards while immediately reducing mixing the time by more than 25%.

Detail:

GC Hahn is a family company with a history that stretches back more than 150 years, supplying the global food industry with products that help determine the taste, texture and stability of foodstuffs from yoghurt and mousse to scones and bread. With offices in 32 countries, they are at the forefront of ingredient and additive technology. In the UK, they are celebrating their tenth anniversary at purpose-built premises in Mold, North Wales. GC Hahn holds the highest Halal accreditation outside Malaysia, as well as the highest Kosher standards, requiring stringent DNA testing on batches produced. A wide range of raw materials, including liquid oils, waxes and difficult, pressure-sensitive powders need to be blended to create free-flowing powders or granules. The nature of the food industry also means that as requirements vary, GC Hahn often has to respond to urgent requirements from customers, changing production plans.

When GC Hahn looked to increase mixing capacity, they therefore had a very demanding set of criteria to satisfy. No cross contamination, excellent mixing performance to ensure a homogenous final product, rapid mixing with the flexibility to blend a variety of materials. ATEX hazardous area approval for Zone 22 powder hazard was another pre-requisite. The UK operation is also keen to maintain a reputation as the technical leaders even within their own company – the UK operation being trusted with the most difficult products that GC Hahn makes anywhere.

John R Boone supported GC Hahn throughout the project, from early evaluation of production materials, testing of mixer types and design of mixer blade configuration to supplying a test mixer for production trials to assisting with the design of the entire blending complex within the factory.

At the heart of the installation is a Boone 2000 model horizontal helical blade mixer, HHBM for short, tailored to suit GC Hahn’s exact requirements.

Components of some blends are pressure sensitive and need to be mixed gently to make sure they don’t agglomerate, other mixtures require a higher level of shear and with this in mind John R Boone designed the mixer with a replaceable mixer centre to enable the Paddle Blade or Delta Blade type agitator to be fitted and give GC Hahn complete flexibility. In Helical blade configuration, the product is lifted equally inwardly, outwardly and obliquely, with a very gentle action.

Overall, mixing time has been reduced by more than 25%, and tests are under way with the intention of reducing mixing time still further.

To meet ATEX criteria, the mixer is pressure rated to PED PD 5500. To meet the hygiene standards, which mean that the mixer has to be cleaned regularly by hand rather than using a CIP system, large access doors are required. John R Boone developed a clever pivot system to make sure that the doors are both large enough for access and easy to open yet close with little effort and form a gas tight pressure rated seal.

John R Boone installed and commissioned the system, including all the support structure, feed system and a hopper to discharge to the packaging line.

A very good working relationship has been built up between GC Hahn and JR Boone. As Darrel Wynne, UK Plant Manager of GC Hahn UK put it, “ Our business is a living thing, it’s moving and we have to move with our customers. John R Boone have worked with us every step of the way, and they continue to help us refine and develop the process”.