METHOD OF TREATMENT Russian patent published in 2012 - IPC B08B9/93 B08B3/08 B08B3/10 

FIELD: process engineering.

SUBSTANCE: invention relates to degreasing surfaces and cavities by solvents, preparing to high-sensitivity tightness tests, and may be used in space engineering, aircraft engineering, instrument making, etc. Proposed method comprises placing rocket to be cleaned on rotary device to revolve rocket body about horizontal lengthwise axis, filling rocket tanks partially with solvent to revolve the rocket about said horizontal axis. Rocket body bottom zone in contact with solvent is heated while surface of tanks is cooled. Proposed method differs from prior art in that MINIMUM amount of solvent M_s makes where C_F is initial (before cleaning) mean-statistical specific amount of soluble impurities on inner surface of tanks, kg/m²; C_Ftol is tolerable residual amount (after cleaning) of soluble impurities, kg/m²; F is total area of inner surface of tanks, m²; δ is mean thickness of solvent film on aforesaid said inner surfaces in cleaning tanks, m; p_v,p_f are densities of vapor and fluid phases of solvent in cleaning, respectively, kg/m³; V is free inner volume of tanks, m³, while linear rotational speed of rocket cylindrical shell about axis is set to allow evaporation per unit time of maximum amount of solvent G_max(kg/s): where v is linear rotational speed of rocket cylindrical shell about axis, (m/s); λ is factor of heat transfer from shell outer wall to solvent, kJ/m² s K; t_SMmax is maximum tolerable temperature of tank structural material heating, °C; F_c is total area of contact of solvent with tank inner surface, m²; r is solvent specific evaporation heat, kJ/kg; c_SM is heat capacity of rocket tank material, kJ/kg K; t_s is solvent temperature in tank necessary for efficient washing effect, °C; t_H is tank shell temperature in area not in contact with solvent ( equal to ambient temperature), °C; A is mean thickness of tank shell, m; V is linear speed of tank wall rotation, m/s; L is tank cylindrical section length, m; ρ_sm is density of tank structural material, kg/m³.

EFFECT: higher quality of cleaning and preparation for high-sensitivity tightness tests, minimised consumption of power and materials, lower costs.

3 cl, 1 dwg