Tubular Chain Conveyors: Working Principle, Core Structure and Classification Explained

A tubular chain conveyor is a flexible, enclosed powder conveying machine, classed as continuous conveying equipment. Its core design revolves around three principles: enclosure, low degradation and flexibility. Compact in structure and smooth in operation, it can be arranged horizontally, on an incline or vertically in combination, overcoming the space limitations of conventional conveyors. The detailed working principle, core structure and model classifications are set out below to give industry users a complete understanding.

I. Core Working Principle

A tubular chain conveyor uses a high-strength transmission chain as the traction element, with wear-resistant discs mounted at regular intervals along it. The whole traction assembly is enclosed inside a round or square steel pipe. The head drive unit turns a sprocket that pulls the chain and discs in a continuous cycle inside the pipe. Material entering through the inlet is pushed along by the discs in sync with the traction assembly until it reaches the outlet and is discharged. Throughout the process the material is enclosed within the pipe, so it never contacts outside air and there is no dust or leakage.

This is a low-speed plug-flow conveying principle. The gentle running speed causes no impact, friction or re-grinding of ultrafine desulfurization agents or light powders, largely preserving the original fineness and flowability of the powder. It is especially suitable for conveying micron-grade ultrafine powders used in dry desulfurization, avoiding any degradation of powder performance during conveying that would affect desulfurization efficiency.

II. Core Structure

A complete tubular chain conveyor consists of six core components, each with its own role in ensuring stable operation: first, the drive unit, comprising motor, reducer and sprocket assembly, which provides stable power and supports variable-frequency speed control; second, the traction assembly, including the chain and discs, made of wear- and corrosion-resistant materials for long continuous running; third, the conveying pipe, a fully enclosed seamless steel tube that prevents dust leakage and can be spliced and turned as required; fourth, the tensioning device, installed at the tail, which automatically adjusts chain tension to prevent slack and chain jumping; fifth, the inlet and outlet devices, which connect to upstream and downstream equipment and can be fitted with sealing valves to prevent backflow; and sixth, the electrical control system, which provides start/stop control, overload protection and fault alarms and supports automated interlocking.

III. Main Model Classifications

By conveying layout and structure, tubular chain conveyors are mainly divided into three categories: horizontal, vertical and loop (ring) types. By application, they are available as general-purpose, wear-resistant, corrosion-resistant and explosion-proof models. The dry desulfurization industry prefers wear-resistant, explosion-proof models to meet the anti-static and wear-resistance requirements of powders. Based on site space and conveying distance, combined horizontal + inclined + vertical configurations can be customized to flexibly suit a wide range of complex working conditions.