METHOD TO PREPARE FUEL STORAGE TANK FOR LEAKAGE CHECKING Russian patent published in 2015 - IPC B08B3/00 

FIELD: machine building.

SUBSTANCE: proposed method to prepare a fuel storage tank for leakage checking involves the following: tanks 11 are put into a sealed chamber 1, atmospheric air is removed from the chamber and the tank 1 by vacuum pump 4, 5. Then the tank 11 surfaces are treated by solvent supplied through nozzle units 6, 7 provided that flow rates of the supplied and removed solvent are equal. At the first stage of the preparation process the tank 11 surfaces are treated by solvent jets heated up to the permissible temperature with the total flow rate providing for the removal of surface contaminations and heating of the tank 11 up to the temperature of the supplied solvent during the specified process time. The next stage involves alternating operations of affecting the surfaces by atomized solvent with its total flow rate providing for keeping of laminar-flowing down solvent film on the tank surfaces, and vacuum drying operations. The total duration of periodic treatment operations τ_t, regardless of the total time required for the removal of residual liquid and steam solvent phases from the tank before every vacuum drying operation, τ_d=τ_e+τ_m+τ_s, where τ_e - required total duration of time to remove soluble clogging contaminations from the channel of through microleaks by extraction with the solvent; τ_m - required total duration of time to remove capillary moisture from the channel of through microleaks at vacuum drying; τ_s - required total duration of time to remove solvent from the channel of through microleaks at vacuum drying. Duration of every period of solvent action and vacuum drying $${\tau }_i=\frac{{\tau }_d}{n},$$ where n - total number of affection periods determined by the condition: $$n\le \frac{{\tau }_d-{\tau }_e}{{\tau }_r},$$ where τ_r - duration of time required for the removal of residual liquid and steam solvent phases from the tank before every vacuum drying operation; the duration of treatment by solvent τ_ie and of vacuum drying τ_id in each period are determined as $${\tau }_{ie}=\frac{{\tau }_e}{n};$$ $${\tau }_{id}=\frac{{\tau }_m+{\tau }_s}{n}.$$

EFFECT: increased efficiency and reliability of preparing fuel storage tanks for leakage checking, reduction of labour and financial expenditures on the performance of such works.

1 dwg, 1 tbl