What is the decisive factor for using a screw press to press dry and wet?
Screw press has become the main equipment for solid-liquid separation and extrusion dehydration in industry because of its continuity, environmental protection and durability.The screw shape of the press plays a key role in dewatering. In addition to the previously mentioned single screw press for solid materials and variable diameter screw press for fluid and slimy materials, these simple classifications are not enough to make the material reach the required dryness. That is to say, the drier the material is squeezed, on the one hand, it is determined by its nature, and at the same time, The particle size, stick-slip, moisture content and hardness of the material are all important factors for dehydration.It is very important that the material should be in good condition if the material is to be squeezed dry with a screw press.
For example: kitchen waste, the squeezing of domestic waste, kitchen waste has been exposed to three categories: the waste directly dumped on the table, after screening and crushing, after complete crushing and cooking, the state of these kitchen waste can be divided into solid, semi-liquid and completely liquid. If the vegetable leaves and chopsticks account for a large proportion, the single screw press can be used, and the rest can use the single curve conveying screw and the hyperbolic conveying screw in the special screw press respectively. But now the difference is that although all can squeeze out water, in the test, we found that after a variety of squeezing, the moisture content is 75-80%, two below 75%, the third 60-70%, and because of the different gaps of the screen required by customers, the squeezing dryness data will also change.
The traditional Chinese medicine dregs are generally required to be crushed and then burned after being squeezed, and the required moisture content is relatively low, so the traditional Chinese medicine dregs are generally required to be crushed before entering the squeezer, and the particle size is preferably 2-3mm, so that after being squeezed, the dryness can reach about 40%, which reduces the waste of resources for later drying.
Cabbage leaves, fruits and vegetables, etc., except that the particles should not be less than 2-3mm in crushing.In the case of loss in the screen, it should be noted that the fermentation of these acidic sugary materials plays a decisive role, such as figs, mulberries, blueberries, etc. In the initial fermentation, the fibers in the material are hard enough to squeeze and will not be lost from the screen, and with the passage of time, the organic matter in the material is further damaged by fermentation. O that the material forms a soybean-milk-type fluid, and the special screw press loses the efficacy.
Therefore, the suitable pressing state of the material also determines the type of screw press and the pressing dryness.