Removal of Contamination by Washing Surfaces

In our own investigations we determined the efficiency of the removal of adhering particles as a function of the structure of the jet (continuous or in drops), the specific pressure, and various other factors. 

For creating a continuous jet we used a conical-cylindrical nozzle 8 mm in diameter for a drop-type jet we used hydropneumatic and ejector nozzles The size of the drops was determined by trapping them with a sticky compoimd. (The median diameter of the drops obtained after emerging from the hydropneumatic nozzle was 275 M.) The specific pressure over the cross section of the jet was measured by means of a system of detectors and an MPO-2 oscillograph. 

The average specific pressure of the continuous jet created by the conical—cylindrical nozzle, for a water pressure of 3 kg/cm in front of the nozzle, became 0.22 kg/cm at a distance of 1 m from the latter (or 0.15 and 0.03 kg/cm at distances of 2 and 3 m respectively). 

Under these conditions a fair degree of cleaning with a continuous jet requires a water flow of 15-20 liters/m [350, 351], while Kn exceeds several thousands, i.e., an oil-free surface is cleaned almost completely. If the washing is accompanied by rubbing with brushes, the water flow may be reduced by a factor of about 10 [352]. 

Below we present the values of and Kj for cleaning an oil-free surface with jets of drop structure generated by a hydropneumatic nozzle (distance to painted plates, 1 m water pressure, 2.5 kg/cm air pressure, 1 kg/cm )  

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