Core Technology Analysis of Medium-sized Screw Oil Presses and the Flexible Application Guide of Pretreatment Processes

The pretreatment stage of medium-sized screw oil presses directly impacts the oil yield and quality. This article delves deep into the three key technical points of raw material cleaning, crushing, and steaming, and through the comparison of actual cases of sunflower seeds and sesame, reveals the process differences and optimization strategies of different oilseeds in pretreatment. It also provides practical on - site solutions for common problems such as material blockage and high oil content in oil residues, helping small and medium - sized oil mills establish standardized operating procedures (SOP) to improve the efficiency and stability of the entire production line.

Key Technical Points of Pretreatment

The pretreatment of medium - sized screw oil presses mainly includes raw material cleaning, crushing, and steaming. Raw material cleaning is the first step, which can remove impurities such as stones, dust, and stems in the oilseeds. For example, in a well - run oil mill, after strict cleaning, the impurity content of oilseeds can be reduced to less than 1%, which effectively protects the subsequent equipment and improves the oil quality.

Crushing is to control the particle size of oilseeds. Different oilseeds have different requirements for crushing particle size. Sunflower seeds generally need to be crushed into a relatively fine state, about 2 - 3mm in diameter, while sesame can be slightly coarser, around 3 - 4mm. This is because the internal structure of different oilseeds is different, and appropriate particle size can better release oil during the subsequent steaming and pressing processes.

Steaming is a crucial process that directly affects the oil yield. By adjusting parameters such as temperature and time, the physical and chemical properties of oilseeds can be changed. For sunflower seeds, the steaming temperature is usually controlled at 100 - 110°C for about 30 - 40 minutes, while for sesame, the temperature can be slightly higher, around 110 - 120°C, and the time can be about 20 - 30 minutes.

Differences in Pretreatment for Different Oilseeds

Let's take sunflower seeds and sesame as examples. Sunflower seeds have a relatively hard shell and high oil content. In the pretreatment process, more attention should be paid to shelling and crushing. After proper shelling and crushing, the oil yield of sunflower seeds can reach about 40 - 45%. Sesame, on the other hand, has a smaller size and a special flavor. The steaming process needs to be carefully controlled to preserve its unique flavor while ensuring a high oil yield, which can generally reach about 45 - 50%.

Solutions to Common Problems

Material blockage is a common problem in the operation of oil presses. This is often caused by improper particle size or excessive moisture content of the oilseeds. To solve this problem, it is necessary to adjust the crushing particle size and drying degree of the oilseeds. For example, if the moisture content of the oilseeds is too high, they can be dried in a dryer at a temperature of about 60 - 70°C for 1 - 2 hours.

High oil content in oil residues is also a headache for oil mills. This may be due to improper steaming parameters or problems with the pressing process. By optimizing the steaming parameters and adjusting the pressure of the oil press, the oil content in oil residues can be reduced. For example, in some oil mills, after optimizing the process, the oil content in oil residues has been reduced from 10% to about 5%.

"The key to improving the oil yield and quality lies in the strict control of the pretreatment process," said an industry expert. "Each step has its own scientific basis, and only by following these rules can we achieve good results."

Whether you are a novice in the industry or an experienced operator seeking efficiency breakthroughs, this practical guide can answer your questions and empower your production decisions. Click here to learn how to develop your own pretreatment SOP and improve the efficiency of your oil production line!