Case study: edible rapeseed oil filtration
The customer is producing rape seed oil (raffinated and hardened oil) for the Food Industry. Common production process with seed pressing, crude oil filtration via vertical pressure leaf filters (54V type) and a raffination step with filtration of bleaching earth via vertical pressure leaf filters (NVD1200-type). Finally a part of the oil is being hardened in a hydrogenation step with Ni-Cat. Ni-Cat is being filtered out by a cricketfilter.
The different end products are pumped via polishing filters (bag filters with filter bags) into storage tanks. From there the end products will be pumped into trucks. Required capacity to be able to load trucks in time is 70m³/h. The viscosities are moderate, approximately at 35-40mPas. The refined oil is being filtered at ambient temperature of ca. 20-30°C while the hardened Oil has to be filtered at 90-100°C because at temperatures below 80°C the fluid starts to become distinctly more viscous and below 70°C it is already almost solid fat.
The customer often found remaining particles in their storage tanks due to accumulated impurities from pumps/ piping and other process equipment between the polishing filters and the storage tanks. Analysis of the content of impurities and also some claims from their customers forced them to look for a reliable filter system between the high capacity truck loading pumps with 70m³/h capacity and the trucks itself.
Filtration Group Process Systems – amafilter – LFC Lochem designed, engineered and built 2 different types of tailor made Multi Bag filter housings, each suitable for 6 filter bags. For the high temperature application of the hardened rape seed oil Filtration Group supplied steam jacketed housings. This included preparation for on site installation of thermal insulation to give customer the opportunity to keep the product temperature at 90-100°C.
One of the challenges during planning and engineering was the very, very limited floor space at the site. The customer did not plan any extra space for installation of the new safety filters. The solution was to install the filters directly between the storage tanks and the piping in the storage tank space, which was quite challenging.
Filtration Group and its in house engineers were the right partner here to find a tailor made solution for this customer.
Considerable additional value was achieved by recirculation and re-filtration and a better product quality . Claims for our customer went down to zero due to the final safety filtration step.
Other positive effect
A benefit of AP filter bags (with stainless steel snap collar ring) is that they are steam sterilizable (for short periods like required here in this application).