FIELD: procedure of industrial processing mainly of hydrocarbon liquids. SUBSTANCE: method of resonance excitation of liquid consists in transfer of the energy of mechanical oscillations to it with the aid of their source engageable with the liquid and operating at one of the fundamental frequencies submitting to general relationship FN = F1N-1/2, where N ≥ 1- selected integral number, F1= 63.992420 kHz - fundamental frequency of oscillations at N= 1. At a use of a rotor hydrodynamic source of oscillations resonance excitation of liquid is accomplished at observance of relationship nR= 1.16141 F, where n[1/C] - rotational speed of the impeller, R[m] -radius of the impeller peripheral surface. The device for resonance excitation of liquid has a rotor with an impeller made in the form of a disk and a ring wall with a number of outlets, and a stator with an inlet communicating with the impeller cavity, and the coaxial wall forming an annular chamber with the impeller communicating with the outlet. R = 2,8477729 n-2/3• 104, mm and the value of the fillet radius of the coaxial wall makes up R1 = R+BS(2π)-1 mm, where B ≥ 1 is selected integral number, S= 7,2973531 mm is pitch of impeller outlets. The method for fractioning of liquid consists in preliminary treatment of it with the aid of the above preswitched device for resonance excitation, feeding of the preliminarily treated liquid to the rectifying column and discharge of distilled and residual fractions. Subjected to preliminary treatment is mainly the partial flow of liquid branched out from the main flow. The plant for fractioning of liquids has a feed pump, at least one rectifying column and the above preswitched device for resonance excitation successively connected between the outlet of the feed pump and the inlet of the rectifying column. Provision is made for closing-adjusting controls for branching of the partial flow of liquid and its combining after preliminary treatment with the general flow. EFFECT: maximized efficiency of preliminary treatment of liquid and thus maximized output of the most valuable light fractions. 16 cl, 4 dwg, 1 tbl
