METHOD FOR CLEANING METAL SURFACES FROM DIELECTRIC DEPOSITS Russian patent published in 1998 - IPC

FIELD: cleaning inner surfaces of metal tubes. SUBSTANCE: deposits are exposed to cylindrical shock waves during electrical breakdown effected at points located in at least two rows. These rows and points in each row are spaced apart through maximum 3.2-fold thickness of deposit material. Parameters of high-voltage pulses applied between metal surface and needle electrodes meet inequalities $$$, $$$, $$$, where W is high-voltage pulse energy, J; n is number of discharge channels; $$$ is ultimate strength of deposit material at uniaxial tension, N/sq.m; $$$ is pulse amplitude, V; $$$ is generator equivalent pulse length corresponding to 50% of its stored energy, s; H is distance between pointed ends of electrodes and surface, m; E is electric field strength meeting inequality $$$, V/m; $$$ is electric field breakdown voltage in deposit material, V/m; h is averaged thickness of deposit layer, m; V is velocity of longitudinal sonic wave in deposit material, m/s; K is factor equal to $$$, s/V; $$$ is pulse rise time, s. EFFECT: facilitated manufacture, reduced power requirement more than zone of high mechanical energy concentration produced in deposit layer simultaneously to destroy deposit material. 4 cl, 4 dwg