What is the SLG85-A twin-screw main unit suitable for?

The SLG85-A large twin-screw extruder main unit is used for food extrusion and puffing processing.The applications listed in the manual include fully expanded snacks, cereal granule porridges and flake porridges, as well as fillings for cold foods, pastry fillings, and solid powder fillings.The equipment consists of a main unit with an automatic feeding device, an extrusion main unit, a control cabinet, an automatic water injection machine, and a cooling water tower. The materials must be uniformly mixed before entering the main unit.

Working Principle

The raw material is forcibly conveyed within the sealed barrel by two co-rotating, intermeshing twin screws, while simultaneously subjected to mechanical shear and barrel heating.The material forms a rheological body under high temperature and high pressure, and expands after being extruded through the die into an ambient temperature and pressure environment.The manual states that during the extrusion process, starch can undergo gelatinization, resulting in a fluffy texture of the material.The screw features a combination of double-start arc-shaped grooves, kneading blocks, and shear rings to accomplish the processes of conveying, mixing, kneading, and shearing.

Core Technical Parameters

The total power of the main equipment is 121 kW, the main drive power is 90 kW, and the heating power is 6 × 4 kW;The screw diameter is φ85mm, the length-to-diameter ratio is 1:21, the screw speed is 0–406rpm, and the processing capacity is 500–800kg/h.The main unit's temperature control range is 0 to 399°C, and it employs variable frequency speed regulation.The overall dimensions of the extrusion main unit are 4800×1300×2500mm, with a machine center height of 1200mm and a workbench height of 2400mm.

Main Structure and Auxiliary Units

The drive power of the forced feeding device is 2.2 kW, the screw diameter is φ81 mm, it adopts variable frequency speed regulation, and the screw speed is 75 rpm.The barrel consists of six sections, equipped with four 6KW infrared stainless steel heating rings and zone cooling.The lubrication system consists of a gear pump, oil tank, oil passages, and a dedicated oil cooling device.The automatic water injection machine is used to quantitatively add water or other liquids to the barrel. Its screw pump drive power is 0.55 kW, the stirrer drive power is 0.37 kW, and the flow rate range is 0.06–0.8 m³/h.

Key Points for Startup and Maintenance

Before conducting an empty-load test, inspect the feed screw, barrel, and screw for foreign objects, and check the electrical components, lubrication connections, and transmission parts.The main unit preheating should adopt segmented heating;Before starting the main motor, the oil pump must be turned on and allowed to supply oil for 5 minutes.During production, monitor the main unit's current; the manual specifies that the operating current must not exceed 165A.Before stopping the machine, reduce the feed and add water. Only stop the main unit after the die head has ceased extruding material.The reducer lubricating oil is recommended to be changed every six months, and the thrust box and distribution box should be regularly inspected, cleaned, and have their oil changed.