The purpose of this piece of equipment is to indirectly heat, cool, or dry a variety of materials in the form of sludge, paste, cakes and bulk solids. These machines are provided for the chemical, industrial, and mineral industries. The hollow flight system utilizes fluid flow internal to the screw flights that is in counter flow to the continuous metering of material that is being conveyed. The hollow flight system can be equipped with speed control, mixing paddles, insulation, spray bars, external heat jackets, etc. based on the process needs. The unique benefit of the hollow flight system is that material contamination is avoided by keeping the hot or cold fluid separate and sealed. This system has proven to be a high efficiency solution for temperature and moisture control. Variable frequency drives (VFD’s) are often used to control variance in feed rates, or material infeed conditions if retention time within the unit needs to be increased or decreased. The screw and paddle design surrounding the shaft flights can be designed for volumetric flow or continuous metering flow, which can increase or decrease your retention time desired. Variances in the units design include single, dual and quad screw designs. Increasing the number of screws will effectively increase the surface area of heat transfer and allow for increased material throughput.
Materials known to be effectively used in this system are: molybdenum, petroleum coke, limestone, ash, pesticides, potassium chloride, carbon black, sodium, alumina, iron oxide, sodium tripolyphosphate, calcium carbonate, polymers and plastics, clay, and more. Please give us a call with you application specific inquiries so we can size the best piece of equipment per your application.