Interrupted flight extruders

An interrupted flight extruder is mechanically different from other extruders because it was developed from a screw-press. A screw-press and an interrupted... 

Fig. 19.8. Cross-section of an interrupted-flight extruder used for producing toasted full-fat soy flour (Source Provided by the Anderson International Corporation, Cleveland, OH).

Introduction of the expander, a high-shear extruder with an interrupted-flight screw, in the mid-1980s revolutionized oilseed extraction practices. Essentially all solvent-extracted cottonseed, and approximately 70 percent of domestic soybean tonnage now are processed... 

The majority of these parameters are closely interrelated, and the key to obtaining a quality product is to find the best combination of three different types of extraders, namely dry extruders, segmented single-screw extruders, and interrupted flight extraders/expanders, which are discussed in this chapter. 

There are mainly two types of wet extruders that are being used to process soybeans (1) segmented single-screw extruders and (2) interrupted flight extmders/ expanders. 

Several types of extruders are used to prepare FFSFs, including the interrupted-cut flight extruder shown in Fig. 19.8. A flow diagram for making extruded FFSF is shown in Fig. 19.9. 

B) Brabender DSK 42/7 Counterrotating twin-screw extruder, closely intermeshing 42 7 0.86 With interrupted flights... 

An exceptional type of single-screw extrader is the pin extruder. In this extruder the screw has interrupted flights and it rotates in a barrel with stationary pins. The effect is twofold because of the rotation of the screw a good mixing action can be achieved, and because of the increased resistance against slip the throughput is more stable than in ordinary single-screw extruders. However, the pressure built up in this type of machine is rather poor. In some special types the screw not only rotates but also oscillates in an axial direction. 

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