Roger Bracewell, owner of GA Pet Food Partners in England, wishes to be able to guarantee that the produced petfood contains the exact prescribed recipe. To achieve that contamination-free production is imperative. Since the company works with almost 400 ingredients and over 800 different formulas, far-reaching changes were required, as well as joining forces by different professionals.
An impressive factory expansion, realised by ground-breaking collaboration. This is probably the best way to describe the expansion at GA Pet Food Partners in Bretherton, Lancashire (England). The British private label manufacturer was facing a capacity issue for its storage of
raw materials and wanted to improve the exploitation of the capacity of the three extrusion lines. At the same time Roger Bracewell, the company owner, wanted to have full control over the tracking and tracing of the raw materials within the plant. He wants to be able to guarantee that the food produced contains the exact prescribed recipe. This requires a contamination-free production. “This whole thing exacted a major change at this customer”, says Dirk Zoontjens of KSE. “Mainly because he has an annual operation of 600,000 manual weighings, nearly 400 ingredients over 800 different formulas that increase and change continuously. These are quite unusual numbers for a pet food manufacturer.” There was a lot involved to make everything traceable within the plant.
Bracewell was aware that this was an unusual project. So, for the realisation of the so-called Ingredients Kitchen, he chose to bring different professionals together. Eep Van Kooten, working with Van Mourik: “he wanted an expert for each section, for instance, transport, routes, storage and mixing. There is not one single party that is utterly skilled in everything.” Bracewell contacted KSE in 2013. Zoontjens: “We were approached to think together about the concept. Since the customer indicated straight away that he wanted the best available in every field, we fairly quickly approached other companies that seemed to fit into the project and would be capable of adequate collaboration”. Van Mourik (intake & transport), Dinnissen (mixing and grinding), SCE (storage silos) and KSE (dosing and weighing, container transport and automation) became the main parties involved.
Koen Verbrugge of SCE infers: “As such we had all renowned names together”.
Together with the owner, the four parties started a pre-engineering process, “a unique process”, as Van Kooten calls it. “Normally you make the best possible estimation of the situation. This does not prevent though that during the engineering phase modification appears to be required. The construction, for instance, must be made more solid than was thought beforehand”, he says. “Hence, uncertainties are always there. To anticipate that, we started a pre-engineering process, which eventually lasted a year. We had biweekly meetings with parties involved and GA Pet Food Partners. We wanted to get a good focus on everything and create a flow scheme as well as an installation drawing.” After a year of intensive talks and alignment, we received a green light for the realization of the project.
Preventing contamination was the key issue. “It was a challenge for all parties to get the product across the production line without it getting contaminated”, says Peter Raeven, working at Dinnissen Process Technology. So, it was decided to keep the weighed raw material together as a batch, during the entire process.
Raw materials that arrive as bulk, are stored in one of the 90 silos for raw materials, which are loaded by two different intake lines. The bulk raw materials are weighed in a transport container (weighing station) and then end up in the grinding/mixing line. All raw materials arriving as bagged goods or in big bags are transhipped, into plastic pallet boxes of around 1.5 cubic meters. When these raw materials are required for a production batch, the pallet box is unloaded into a dosing container, after which the raw materials are dosed and weighed and further processed via one of the 150 transport containers. Such a transport container is lifted to the top of the mixing/grinding line to be unloaded. Zoontjens: “So dosing takes place straight from the dosing containers. As such the remaining residues while filling the product silos are foreclosed. The batches are collected completely in one of the transport containers. After mixing, sieving and grinding the very same container picks up the batch for the extrusion process.”
The transport containers carrying the batch are taken to the extruders, some 300 metres away, by AGV’s, Automatically Guided Vehicles. “After the transport containers have been unloaded, they are automatically cleaned, making them ready to be used for the next batch. A perfect isolation is created between one product and the other. Simultaneously complete disconnection is ensured between collecting batches and the actual extrusion process. Advantage of this is that the extruder capacity can be optimally used.”
Christian Rietman, project leader at Van Mourik, is impressed by the enormous warehouses. “The 30,000 pallet boxes move fully automatically, via a rail system with sensors. It is an incredible sight.” Raeven adds: “this container system is unique. Many pet food manufacturers attempt to prevent contamination. This company even goes a step further in minimizing contamination by strict isolation of products and cleaning of containers.”
Special chain conveyors
The use of transport containers strongly contributes to hygienic operation and preventing contamination. In addition, in their own field the parties involved have contributed to keep contamination at a minimum level. This started with the transport. Van Mourik supplied the conveyor chains towards the raw material silos and dosing silos. Each of the intake lines has a pit, allowing 100% isolated transport routes, with dust extraction on the walls. The material that is shaken off last will be the last to end up in the silo. Magnets and trammel screens help to remove any physical pollution.
“In total there is about a kilometre of conveyor chains installed”, according to Van Kooten. “In order to prevent cross-contamination special chain conveyors, with minimal residue, were used. This mainly implies that a larger type of chain was used than would be required based on capacity. This allows working at lower transport speed, so that the product ends up at exactly the right spot.” In addition, the slack between the guide strip and the chain was reduced, realizing less shaking of the conveyor chain and the transport system was equipped with a rinsing device in the tensioner. “Using this high-pressure cleaning system, at the end of a batch, the residues can be blown from the system.”
SCE supplied 90 raw material silos and 60 dosing silos. Also, here hygiene was a major point of attention. “We can supply silos that drain perfectly, are maintenance-friendly and self-cleaning.” The silos were adapted to a design that is also used in the flower industry. “For that reason, we designed a special type of funnel, the patented butterfly funnels. Classic funnels have an inclination of 60 degrees and 55 degrees in the corners. For the butterfly funnels the angle is equal everywhere, namely 70 degrees. This ensures excellent draining”, according to Verbrugge.
Mixing and grinding
Dinnissen’s challenge was to keep the batches together during the grinding and mixing process. “We have made use of special mixers and small bunkers that leave little product residue. We use a pre-screen and automatic screen changing on the hammer mills. To reduce erratic grinding, mixing also takes place before grinding, using double axel paddle mixers. During the mixing period, the system is self-cleaning because of adjusting the swirl”, Raeven tells. In addition, Dinnissen has optimised the standard machines. “We took a good look at our grinding/mixing lines and analysed where optimisation was possible. Eventually making many small changes has resulted in negligible contamination”.
The Ingredients Kitchen of GA Pet Food Partners is fully automated. “The warehouses functions fully automatically, just like other parts of the plant”, Zoontjens explains. “Unmanned forklifts and trucks are driving around.” Three software companies were engaged to automate the entire plant. “All this just to exclude human errors.”
Currently the work activities in England are at the concluding stage. SCE have finished their part already. “The silos were completed early 2017. We built 150 silos in just four months. Quite a few”, Verbrugge states. Van Mourik too has completed the mechanical work activities. KSE is still working on it. “We have started connecting the electrical installation. This spring we will start the implementation of the controller”, according to Zoontjens. We expect to have finished the expansion of the plant by mid-2018.
But that is not all. “GA has a significant expansion drive”, says Rietman. “In the design, a capacity growth of 100% was taken into account. In addition, the extrusion lines will be equipped with a mixing/grinding station that processes ‘rework’ of the extruder directly, within the same batch of future batches”, Raeven tells. This mainly concerns starting material that is just not good enough yet. This product will be directed back into the current run, grinded, mixed and reprocessed. As such, high-quality material is optimally exploited. Zoontjens: “GA Pet Food Partners wants to handle rework in a smarter and better way. This way they can maximise the use of the raw materials.”
Each of the parties involved is excited about the collaboration. “The market has shown great interest in transparent cooperation. We have heard this many times. For KSE such cooperation is unique, yet certainly worth repeating.” Verbrugge agrees: “collaborations like this are far too rare. One customer wants it all from one single party, while the other demands a specialist in every field. The great advantage of the latter is that the customers gets the best solutions.
Who did what?
Van Mourik: supply of intake transport system, with a capacity of 100 tonnes per hour. Consisting of: two intake lines for bulk raw materials poured via the pit, with extraction walls. Every line is fitted with a casca-demagnetiser and drum sieve, some five elevators, 32 conveyor chains (approx. 1 km in total).
KSE: supply of the entire dosing systems (from containers and silos), the container handling system for dosing containers and transport containers and the overall plant operation (PROMAS ST). In addition, KSE takes care of the coordination between the customer and the Belgian and Dutch partners.
SCE: supply of 90 raw material silos (with a total content of some 10,000 tons) and 60 dosing silos (with a total content of approx. 3,600 tons). In addition, SCE ensured the engineering of the entire steel construction of the storage building and the production lines. The steel construction is on a concrete floor for the sake of fire safety.
Dinnissen: supply of three grinding and mixing lines, consisting of paddle mixer, pre-screens, hammer mills with automatic screen changer, and pneumatic transports for the Ingredients Kitchen. Dinnissen also supplied the rework- systems for the extrusion lines.
Other: For ATEX and safety aspects external advisors were hired. The mechanical engineering businesses themselves provided the hygienic parts for the installations, such as hatches and cleaning nozzles.
Source: De Molenaar