The use of vacuum technologies and equipment in the processing of agricultural products can significantly reduce the loss of biologically active substances and functional components in the final product. Liquid ring vacuum pumps (LHVN) are considered in the work. A significant disadvantage of the LHVN is its low efficiency (about 50%), which is due to hydraulic losses due to friction of the liquid against the stationary pump casing and excessive power consumption for compressing the gas phase. A new design of a combined LHVN with a kinematic lock and an adjustable discharge window (LHVN KM) is proposed. The design allows to reduce the power consumption for the friction of the working fluid against the body; in the initial modes of operation - to minimize over compression and overflow of the gas phase from the injection area to the suction area; at limiting operating modes - to ensure the displacement of the gas phase from the working cavity and eliminate the effect of "locking", accompanied by destabilization of the working process. A standard size range of LHVN KM for various technological processes is presented. For LHVN KM of especially high speed of action, it is proposed to carry out the working process by rotating the body with blades through the designed drive. The scheme and methodology for calculating the drive on the basis of GOSTs and known methods for calculating gearing are described. In order to reduce the weight and size parameters of the LHVN KM, it is proposed to manufacture drive and pump parts from polymeric materials with subsequent hardening by a magnetothermal method.