Centre Bar Oil Expeller

A center bar oil expeller, also known as a central bar oil expeller or simply a screw press, is a mechanical device used in the extraction of oil from various oilseeds, nuts, and oil-bearing materials. It operates on the principle of compressing and forcing oil out of the raw materials by using a rotating screw or worm shaft within a cylindrical barrel or cage. Here is a description of the key components and the operation of a center bar oil expeller:

• Hopper: The raw material (such as seeds or nuts) is loaded into the hopper, which feeds it into the expeller chamber.
• Expeller Chamber: The expeller chamber is a cylindrical enclosure where the oilseed is subjected to pressure and friction. It contains the central bar or screw, which is the heart of the expeller.
• Central Bar or Screw: The central bar, often referred to as the worm or screw, is a helical shaft that rotates within the expeller chamber. As it turns, it pushes the material along the chamber, compressing it and gradually reducing the size of the oil-bearing cells.
• Cage or Barrel: The central bar is surrounded by a cylindrical cage or barrel with perforations or slots through which the oil can flow. The cage keeps the material within the chamber while allowing the oil to escape.
• Pressure Adjustment: Many oil expellers have an adjustable pressure mechanism that allows operators to control the level of pressure applied to the material. This is important for optimizing oil extraction efficiency.
• Drive Mechanism: The central bar is typically connected to a motor or an external power source, which rotates it at a controlled speed.
• Oil Outlet: As the material is compressed and heated due to the friction generated by the rotating screw, oil is forced out of the oil-bearing cells. The oil flows through the perforations in the cage and collects in a receptacle or trough at the bottom of the expeller.
• Residue Outlet: The remaining solid material, often referred to as the cake, exits the expeller through a separate outlet. This cake can be used as animal feed or further processed for various applications.
• Heating: In some applications, the expeller may include a heating component to help reduce the viscosity of the oil and improve extraction efficiency, especially when working with materials that are high in oil content but have low free-flowing characteristics.

The operation of a center bar oil expeller involves continuously feeding the raw material into the hopper, which is then conveyed into the expeller chamber by the rotating central bar. The pressure and friction generated within the chamber cause the oil to be expelled from the material, while the residue (cake) is pushed out through a separate outlet. The extracted oil is collected, and the process continues until the desired amount of oil has been obtained.

Center bar oil expellers are commonly used for extracting oil from a variety of oilseeds, including soybeans, sunflower seeds, rapeseed, peanuts, and more. They are widely used in small to medium-scale oil extraction operations due to their simplicity, efficiency, and versatility.