Vegetable cleaning is one of the essential processes in vegetable processing and cleaned vegetable production. At present, vegetable cleaning mainly relies on hand and its mechanization procedure is lower. Now, there are vibration spraying and drum type vegetable washing machine. The vibration spraying type vegetable washing machine has two cleaning pools. Vegetables in vibration cleaning pools first make repeated movement for preliminary cleaning, and then get into the spray pool with water spraying to complete the whole cleaning process. This type of vegetable washing machine uses large amount of water and has great damage to leaf vegetables.
In the liquid containing a lot of bubbles, huge instantaneous pressure would be generated when the bubble in liquid collapses and bounces back. When the collapsed bubble is close to the solid boundary of the flow, the repeated action of high-pressure of the collapsing bubbles in the water flow can destroy the surface of the solid, thus producing cavitation phenomenon. The bubble bursts near the surface of vegetables, the spherical bubble moves along the jet flow to the rigid solid surface. Due to submerged jets on the solid surface that form a thin layer of sheetflood, so there is crossflow of the liquid between the bubbles and the surface of vegetables, which makes the liquid pressure of the bubble wall near the surface of vegetables (called near wall) lower than the end of far (called far wall) and the centripetal movement speed is slower than other parts. When the bubble center moves to the vegetables, the distance between the near wall and the surface of vegetables is almost invariant. To maintain the momentum conservation (not considering the influence of liquid viscosity), the bubble must make accelerated motion and the far wall caves inward near the near-wall. High speed micro jet would be formed when the near wall is penetrated. This kind of micro jet points at vegetables, its damage and erosion ability are very strong. Through calculation and measurement, the velocity of the micro jet near the solid wall can reach 70~180MPa when the moving bubble collapses. Such high dynamic pressure can completely wash off the contaminants on the vegetable surface and shorten the cleaning time. Moreover, this is only the effect of micro jet on the surface of vegetables for one time; when the bubbles in the water continue to produce, increase and burst, the impact pressure of bubble collapse continuously acts on the vegetable surface, effectively removing the pollutants from the vegetable surface.
The bubble vegetable washing machine produced by our company has compact structure, high degree of automation with circulating pump and filter tank to implement clean water cycle and water conservation. Add new water according to the actual production situation. The motor of conveyor belt can be adjusted with the speed change function. Vegetables are washed when being transported through the net chain with automatic feeding and discharging. The conveying speed of conveyor belt can be adjusted according to the production needs. Simple operation and maintenance, high efficiency of vegetable washing machine make it an ideal food cleaning equipment.