Soaking screw conveyor for rice boiling

Soacking screw conveyor for rice boiling. The screw conveyor is used in a process combining:

1. Material transport
2. A process – in this case soaking of rice as a pre-process for boling

Key designing point for the soaking screw conveyor

1. The speed of the screw rotor must be controllable by using a frequency inverter
2. In a process screw conveyor you do not only control the mass flow, but also the process – in the case the retention time

A process screw conveyor is always soling 2 functions – the mass flow and the process. Therefor you shall be cautious, when you work this. In worst case you cannot deliver the needed mass flow if the process takes longer time!

Features for the soaking screw rotor

1. The screw rotor is manufactured after the same concept like a cylinder lawnmower
2. This concept acts like a scraper in the bottom
3. On one of the pictures you can see a hole through the screw flights. This has been made for easier cleaning

BEMA have experience for many types of process screw conveyors over the years. Designing these requires a close cooperation with the end customer. BEMA is not a process specialist. BEMA is a machine builder with specialized in screw conveyors and related components.

See another example of a cooking screw conveyor

What is in generally needed when designing process screw conveyors?

1. Design the screw conveyor long enough
2. Increase the diameter of the screw conveyor

Following these guidelines you can always increase the retention time by increasing by reducing the speed. If the diameter is conservative, you can increase the filling degree. If you need more of the same machine, start to manufacture one and check the function carefully. You can afterwards improve the design, when you are comfortable with process.

FAQ – Soaking Screw Conveyor for Rice Boiling (Approx. 250 words)

1. What is the primary purpose of a soaking screw conveyor in rice‑processing lines?

A soaking screw conveyor is designed to gently transport rice while simultaneously submerging it in water to achieve uniform hydration before boiling. This controlled soaking phase is essential for ensuring consistent cooking results, reducing breakage, and improving the final product’s texture. By combining transport and soaking in a single unit, processors gain a more compact, hygienic, and energy‑efficient solution compared to traditional soaking tanks.

2. How does the system ensure uniform soaking and product quality?

The conveyor’s design maintains a steady, controlled residence time, allowing each grain to absorb water evenly. Adjustable parameters—such as water temperature, flow rate, and screw speed—enable operators to fine‑tune the process for different rice varieties. The continuous movement prevents clumping and sediment buildup, ensuring a cleaner process and more predictable quality outcomes.

3. Can the soaking screw conveyor be integrated into existing production lines?

Yes. The system is typically engineered for seamless integration with upstream washing units and downstream boiling or steaming equipment. Its modular construction allows customization of length, capacity, and inlet/outlet configurations, making it suitable for both new installations and retrofits. Integration also supports automation, enabling consistent throughput and reduced manual handling.

4. What maintenance requirements should operators expect?

Maintenance is generally straightforward. The conveyor is built with durable, food‑grade materials and designed for easy access during cleaning. Routine tasks include inspecting bearings, seals, and drive components, as well as flushing the system to remove starch residues. With proper upkeep, the equipment delivers long service life and stable performance.