Soy Milk Pulp Sludge Decanter Centrifuge Discharging Low Moisture Okara Continuously

In a traditional soy milk plant the slurry leaving the grinding and cooking stage carries between fifteen and twenty five percent dry matter, most of it insoluble okara pulp. Screw presses and rotary screens recover part of the soy milk from this pulp, but the cake that leaves them still contains around eighty percent water, which means a large proportion of the soluble protein and solids is carried away with the waste. The HD-DEC-420 decanter centrifuge replaces that equipment with a continuous, high G-force separation that recovers the liquid phase efficiently and discharges okara at a moisture level of only sixty five to seventy percent.

The machine works by feeding hot soy slurry directly from the cooking tank into the rotating bowl. Because the bowl turns at 4400 rpm and develops 3450 G, the fine okara particles that pass through a 100 mesh screen are captured in the clarified liquid stream and pushed back into the cake by the scroll conveyor, so the liquid leaving the centrifuge is a clean soy milk ready for formulation, while the solids leave the cone in a crumbly, easy to handle form. The result is a double benefit: more soy solids stay in the product, and the waste stream is smaller, drier and cheaper to transport, compost or sell as a by-product to feed and fermentation industries.

• Low Moisture Okara Discharge: A long conical drying section combined with an adjustable differential speed compacts the okara to sixty five or seventy percent moisture before discharge, reducing waste volume by up to forty percent compared with conventional screw presses.
• High Speed Fine Particle Capture: The 3450 G centrifugal field retains particles well below the cut point of vibrating screens, which raises protein recovery in the soy milk stream and improves the body and mouthfeel of the finished beverage.
• Automatic Torque Control: The back drive measures scroll torque continuously and adjusts the differential speed automatically, keeping cake dryness stable when the grinder load, water ratio or bean variety changes during a shift.
• Food Grade Hygienic Construction: All product contact parts are AISI 304 with a smooth, crevice free finish, welded and polished to food standards, and the bowl housing is designed for full drainage so that no residual slurry remains after cleaning.
• Hot Slurry Capability: Bearings, seals and elastomers are specified for continuous operation with slurry at up to ninety five degrees Celsius, which allows the decanter to be installed directly after the cooking stage without an intermediate cooling step.
• Low Maintenance Drive: A fixed ratio gearbox with an oil lubrication circuit, together with ABB frequency converters, gives reliable operation with a service interval of four thousand hours and simple access to wear parts through the housing covers.

The unit is used in soy milk and soy beverage plants, in tofu and yuba factories where pulp must be separated from the protein slurry, and in plants producing soy protein isolates and concentrates. It also suits other plant based milk processes, including oat, rice and mung bean slurries, where the same fibre and starch pulp has to be dewatered and the liquid phase recovered. Because the discharge cake is dry and friable, many customers sell it to local feed producers or use it as a fermentation substrate, converting a disposal cost into a small income stream while simultaneously raising the yield of the primary product.

The decanter is cleaned, drained and treated with a food safe corrosion preventive agent on machined surfaces, then mounted on a fumigated wooden skid and enclosed in a seaworthy plywood case with desiccant and a vapour barrier. Control cabinets, spare screens and tools are packed in a separate crate. Documentation covers the operation and maintenance manual, cleaning procedure, electrical and instrumentation drawings, material certificates and a spare part list. A water run test with vibration and temperature records is performed before dispatch, and the warranty period is twelve months from commissioning under normal operating conditions.