Abstract
Physical factors affecting on the washing effect of the spray and soaking washing were investigated for the purpose to design effective washing installations. The following results were obtained.
1. Spray washing: 1) The washing time and the gravity flow rate of water had much influence on the washing effect, whereas the temperature of water had less influence. 2) Following ex- perimental equqtion was obtained. η:washing effect (%), υ: the mean velosity of sprayed water at nozzle outlet (cm/sec), G: the gravity flow rate of water (g/sec), θ: washing time (sec), g: gravity acceleration (cm/sec2).
2. Soaking washing: 1) The effects on the soaking washing were much less than that on the spray washing at the same washing time. 2) The washing effect, passing a certain washing time, reached to a state of equilibrium. And then the higher water temperature, the longer the time to a state of equilibrium and the larger the value of equilibrium washing effect was. 3) The washing driving force was related to the gradient of concentration in the film between the agricultural chemicals on the material surface and washing water. 4) Adding a very small quantity of acid (HCL)in the washing water, the washing effect reached to more than 90% in a minute.
