02-20-2023, 01:25 PM
The feed formulation can be fed raw into the extruder, and water or live steam, or both, are injected directly into the extruder to elevate the moisture. The live steam also contains heat. It, and the heat generated by friction as the shaft rotates through the material, elevates the temperature. High-quality fish food in pellets has increased water resistance and low swelling in water, so they are not destroyed.
The shaft forces the material against the discharge end of the barrel thereby placing it under pressure. There are small die openings in the plate covering the end of the extruder through which the moist hot material, now cooked, (actually it is pressure cooked) can exit. The elevated pressure within the extruder can keep all the water in a liquid state.
Even the steam is compressed into liquid water. When the product exits into the atmosphere, the water immediately vaporizes. If the starch is sufficiently cooked to form a gel it will inflate with thousands of tiny pores which cause the product to be of low bulk density.
https://www.floatingfeedmachine.com/sink...d-machine/
The shaft forces the material against the discharge end of the barrel thereby placing it under pressure. There are small die openings in the plate covering the end of the extruder through which the moist hot material, now cooked, (actually it is pressure cooked) can exit. The elevated pressure within the extruder can keep all the water in a liquid state.
Even the steam is compressed into liquid water. When the product exits into the atmosphere, the water immediately vaporizes. If the starch is sufficiently cooked to form a gel it will inflate with thousands of tiny pores which cause the product to be of low bulk density.
https://www.floatingfeedmachine.com/sink...d-machine/