For the production of gelatine products, LEWA provides a series of solutions for various process steps:
How is gelatine produced?
There is a distinction made between bone gelatin, which is obtained from long bones of the legs of calves and cattles and dermic gelatin, which is derived from tanneries waste, pork rind and cows’ and cattles’ heads.
The bones are cleaned, shredded and macerated. The tricalcium phosphate in the bone tissue is removed with dilute hydrochloric acid. Then, it is multiply watered and treated with lime water (“liming”). The next steps are the neutralization of the acid and further washing procedures.
The gelatin is extracted from the washed-out bone collagen in multiple steps, pre-cleaned in separators and afterwards filtrated.
The filtration is a typical application for metering pumps: Diatomaceous earth or perlite slurries are added to the alluvial filter. Flow rates are below 360 l/h and pressures are below 8 bar.
The separation yields an aqueous gelatin solution with a concentration of approximately 6 %. The gelatin content is increased to approx. 30 % in a single or multi-stage vacuum evaporation column. The viscosity goes up to 1500 mPa∙s. This solution now is fed to a drying process.
This is the main application area for multiplex pumps. The task of these pumps is the germ-free metering of the gelatin into a cooler with subsequent fragmentation and drying. The transition from gel-type state to solid state leads to back pressures from 20 to 50 bar.