It is used for extraction of liquor from Khair wood/Cashew peel which then used to make kattha. Material which you want to boil is put into VAT manually or Via an Electrically powered Transfer Pump, this material is then Steam boiled (@80-90C)with 3 times more water than material for 4-5 hours after  which the extracted liquor is transfered to storage tanks or online filter for recirculation via a pump.