Double screw extruder selection criteria and extrusion technology principle

Extrusion technology, as an economical and efficient processing method, has been widely used in food and feed industry in recent years. The twin screw extruder has incomparable advantages over the single screw extruder. Its advantages such as wide processing range, high curing, strong self-cleaning ability and stable operation control are gradually recognized by everyone. For the food industry with high requirements, these advantages of twin screw extruder can be better played. At present, in the processing of extruder products such as breakfast cereal, tissue protein, puffed rice flour, snack food, many manufacturers are gradually inclined to use twin screw extruder.

At present, there are many types of twin-screw extruder on the market, but its performance is quite different. As a food industry manufacturers how to choose a suitable for their own twin screw extruder? What are the characteristics of a high standard, superior performance, twin screw extrusion machine that can bring high returns to the manufacturers?

1. Conditioning equipment is an essential configuration of high performance twin-screw extruder system.

Since the first extruder was used to extrude corn in the 1930s, with the development of extrusion technology, the output of extruder has been greatly improved, and an important performance index of extruder -- ton of material power consumption has been doubled compared with the initial extruder. The reason, of course, is related to the improvement of extrusion technology, but another important factor is the use of conditioning equipment, and conditioning technology has been rapidly improved over the years. Without the development of temperers, it would be difficult to produce large volume extruders today. Tempering through steam to improve material temperature, soften material, reduce material friction resistance, thereby reducing extrusion energy consumption, improve production, improve the stability of the extrusion machine, but also extend the service life of each part of the extrusion machine.

2. Characteristics of high performance twin screw extruder host.

The main index to measure the performance of a twin-screw extruder is whether it can steadily process the qualified extruded products with uniform quality, and whether its output, power consumption per unit output and other indicators are superior. For the food industry, the main index of uniform quality is to control the bulk density of the expanded product within ±5 g/L, the size and color of the expanded particles are consistent, and the size and distribution of the pores inside the expanded particles are consistent. There is a direct relationship between the characteristics of extrusion host and the quality of extruded products.

In order to improve the controllability of the extruder and increase the processing range of the product, the main motor of the general twin-screw extruder is equipped with variable frequency motor which can regulate the speed. For twin screw extruder, the greater the power of the main motor configuration, it is limited by many aspects, such as transmission box restrictions, spindle strength restrictions. The shear and friction of the material in the extrusion chamber are provided by the mechanical energy of the extruder, and the size of the mechanical energy is determined by the power of the main motor.