R.CIP - α-jEt



Around three years ago the people at De Graafstroom decided to further automate their production process of the cheesemaking. A existing production line was optimised with the wish of reducing from two operators to one operator. Especially with the wrongel dissolvers, eight tanks in a row, things didn't go according to plan. Operations manager B. Lavrijsen, Maintenance manager C. de Jong of the dairy factory and J. Wijnveldt from ContratEch Cleaning Solutions look back on three years of collabaration. 

In the dairy factory De Graafstroom in Bleskensgraaf (The Netherlands)  sixty employees in groups of four prepare nature matured round and rectangular cheeses from all the deliverd Milk by the dairy farmers, from Sundaynight 22.00 till Saterdaynight 22.00. B. Lavrijsen as the Operations manager is also responible for process innovations. "With the optimalisation of the existing factory we decided to automate everything, from the filling, dosing of ingrediënts and emptying till the labor intensive hosing of the wrongel dissolvers. Our goal of reducing our amount of operators has already succeeded and thanks to a lot of counseling with ContratEch the tanks are cleaned even better than before. 

The processes
In the factory there is a comprehensive line of production. The milk first transforms for 90 minutes in wrongel. That happens in eight tanks, each having the form of an eight, where in each of the curves of the eight there is a blade turning. After this the mass is transported to a buffer tank to connect the batchproduction from the wrongel dissolvers to the continuous production of the casomatics, where further preperation takes place. Finally the mass gets transported to a vessel where the cheese gets pressed and whereafter the immersion follows. C. de Jong, Maintenance manager at De Graafstroom since one year, as a technician is responsible for the machinery and the buildings. He leads a team of ten people from the Technical service and in the meanwhile already knows a lot about the process. "When I came in here a year ago, there had been a lot of consultations betwee Bas and John for two years".  

The biggest problem was not the principles of the intelligent automatic tank cleaning machine (A-jet), they found that out quickly. But to clean the eight shaped tanks as quick as possible including the knives with the least amount of water, with no residual formed a challenge!. An extra complication arised with the sieve that hangs in the top of the tank and that withdraws moisture during the wrongelprocess. The sieve quickly obstructed because of lumps and had to be toroughly and cleaned manual every time. Eventually De Jong settled the matter by seperating the assignement. "Altough the process isn't quicker, like we wanted it to be in the first place, the cleaning is now more torough and more reliable than the manual cleaning that was done before".

J. Wijnveldt from ContratEch has lots of praise for the people of De Graafstroom. "They have thought with us and collaberated with us for a long time. What a patience". Lavrijsen adds to that: "You're going in a project together, and both put a lot of time and money in it. Than you don't stop so easily". But the patience has been rewarded and the α-jEt now runs to full satisfaction. Where before an operator was needed to keep the cleaningprocedures in check and starting and stopping, it's now done fully automatic. Lavrijsen: "The operator had to work accurately at the second. He had to continuously empty eight tanks and had to know exactly in which phase of the process every tank was in." Now that all happens fully automatic, set on the worst scenario, because all the different kinds of cheese varies in fat content and therefor also in cleaning intensity.

At the top of the tank the sprayhead is mounted in such a way, that it can reach the entire tank from one position. During two minutes the sprayhead produces a jet with 5 Barg that has sophisticated pattern that sprays the knives and the flat bottom of the tank, imitating the operator. At first the knives continue to turn during de wrongel removal procedure, to avoid leaving remaining wrongel on the bottom or just under the knives. Wijnveldt: "De α-jEt is combined with a sophisticated spraybus. In total the installation uses a maxium of about 300 liter water every time. More would burden the system to much. The tanks are placed with a slight slope, to quickly let the water flow away. Where before there was a sieve that had to be cleaned by hand with a maximum of 80% cleaning, now the Inline cleaner (A sanitary clip-on installed, fixed tubular structure) that is attached around the sieve takes care of this automatically. The Wheysieve is retracted upwars because of its own standard driving.

The Inline Cleansystem works with a laserburned tube that is provided with special slots and is laid around the sieve with an angle of 350 degrees. The nozzles create a water curtain (This still with only 5 Barg) and where with cleaning by hand you can't reach, now that's no problem. The thirth improvement point in the tanks is the bushings at the bottom, on which the knives rotate. Formerly there happened all kinds of product accumulation. This to is now a thing of the past, because of specially developed PEEK- busses. Now the tanks have no "dead space" and in combination with specific jets a torough cleaning is created,.. and that completely autonomous.

In these three years both parties have learned quit a bit. Wijnveldt: "I believe we can now handle every dairy project. We've become so much wise but also much grayer". The operating system also formed a challenge. Wijnveldt: "W. van Hoek from the company Van Hoek Innovatieve Elektronica, our help and support, is origininally from ow and has developed the electronics specially for the α-jEtOf course this all had to fit in the existing system that is used by De Graafstroom. "At De Graafstroom we coupled all the α-jEt's with a Can bus. But in nowadays it seems wiser that every machine functions as a stand alone. Every piece with it's own direction as a matter of fact. But that is something for the next time, the technics are available. Of course others follow our developments with suspicion. But even now it appears that they can't offer a payable total concept. In the beginning we did speak intensively with the big players in the market, because it would make the marketintroduction that much easier. Sadly, with the execption of a couple of vague promises and squeeshing out of our knowledge nothing came out".