Some processes require preliminary treatment of raw materials before going through the twin-screw extruder. The preconditioner is used mainly for food products : flakes or pellets for cereals and snacks. It is also used for ingredients used in pet food and fish feed.
The preconditioner heats, hydrates and mixes the dry raw materials before extrusion and automatically doses the pre-treated product into the extruder. It optimizes the capacities and the performance of the extruder and enhances final product features.
Functions of preconditioner in twin-screw extrusion process
Introduction of various liquid or dry ingredients in a homogenous mixDepending on the features required for the final product, the pre-conditioner carries out the following functions:
- Heating of raw materials at a controlled temperature
- Pre-humidification of flours before their introduction into the extruder
- Start of starch pre-gelatinization
Technical features of a preconditioner
- The preconditioner carries out a continuous mix upstream, thus optimizing the processing of the product in the extruder
- The mix is done with a counter-rotating screws with adjustable rotor blades, thus producing a more homogenous blend
- Variable blade profiles and speed to adjust for optimal residence time
- Adjustment of various injection points, making it possible to add different liquids: water, steam, oils, etc.
Advantages of Clextral pre-conditioners
- Choice of a complete range of preconditioners adapted to the specifications of the lines or the products being processed
- Variable output speeds from 50 to 20 000kg/h for volumes of 25L to 3000L
Easy to use, ergonomic and safe for operators, with secured equipment upstream and downstream
- Preconditioners are custom-designed by experts to optimize efficiency and enhance the quality of finished extruded products by:
- Ensuring optimal conversion of starches
- Destroying certain enzymes and micro-organisms to ensure food safety and taste features
- Minimizing wear and production breakdowns since preconditioned products are perfectly homogenous and ensure consistent recipes