Industrial saponification plant in Crutcher (batch system) is the widely diffused and cheapest system to produce industrial soap with variable capacities from 1 to 6 Tons of semi boiled soap per hour. It is an easy saponification system, because offers the possibility to check (and correct if required) the batch at the end of the saponification reaction. In this type of saponification plant, the reaction is done at about 90°C.
Filtered vegetable oils or animal fats are pumped into the Saponification Crutcher by means of, then the caustic soda solution is pumped gradually through a distributor ring installed on the top of the crutcher. The fatty materials and the caustic soda are pumped by means of two pumps with one Flow-meter for each pump, to ensure the stoichiometric quantity of each reagent.
During the feeding of caustic soda solution, the mixing screw rotates.
The Saponification Crutcher has a cylindrical shape with a cone on the bottom part. It is equipped with internal enclosed screw stirrer driven by a gear motor to provide for vigorous mixing necessary for a complete reaction. The Saponification Crutcher is equipped with heating jacket or half-pipe coils for the steam that is necessary to heat the mixture of raw materials to speed up the saponification reaction.
Usually the Crutcher works in Atmospheric pressure, but some advanced models are pressurized, in order to work with a high temperature, to speed-up the reaction and fix viscosity problems.
Upon completion of the reaction inside the Saponification Crutcher, it is possible to add Fillers, mainly for laundry soap; after that the the soap is pumped in a feed tank, used as buffer, to provide continuously the soap to the down-stream equipment.
Usually the semi-boiled soap produced with this saponification plant has a TFM of about 61%.
When the capacity is big, a valid alternative is to use two Saponification Crutchers that work in tandem system, instead to use one Saponification Crutcher and one Buffer Tank. During the saponification reaction in the first crutcher, the semi boiled soap in the second crutcher is pumped out from the plant. Also this system provide continuously the soap to the down-stream equipment.