1.Steaming ingredients and making cakes

The characteristics of hydraulic press oil pressing are the forming and pressing of the material embryo and the insulation of the workshop. Oil also needs to be pre-treated, rolled and steamed. Different from other oil production methods, the steamed cooked embryo must be shaped into a cake base, which can be effectively pressed after being stacked.There are three methods of making cakes: manual, semi-mechanized and mechanized.

 2.Hydraulic press

It includes the operation of the oil press body (vertical or horizontal) and the hydraulic system.

The pressing process of each press is divided into three stages: fast pressing, slow pressing and oil draining. The key points of operation are to discharge oil quickly at the beginning, apply low pressure first, then apply high pressure, and then drain oil under steady pressure. After squeezing, once the oil flows out, it is necessary to "press frequently, press lightly, loosen first and then tighten". There must be a rhythm when pressurizing. When the pressure rises to the highest level (such as 35.5MPa of ZQ35 type), the pressure must be stabilized for enough time to drain the oil.

3 .Unloading, “planing and re-pressing” and workshop insulation

After unsqueezing, the edge of the cake will easily absorb oil and affect the residual oil, so it is usually necessary to "plan the edge and press again." The long pressing time of the hydraulic press will cause the loss of temperature and moisture, so the insulation and moisturizing of the workshop are very important. Generally, the temperature is required to be above 30℃ and the relative humidity is about 65%~70%. This shows that the working conditions are poor.