GB2505520A - Belt anti-wrapping system - Google Patents

Abstract

A system comprises two or more shrouds (fig.4) applied to two or more rotatable shafts (fig.1) of a mechanical material processing system, with a belts, marked with a X in fig.7, around the shrouds (fig.4) and an idler roller, such that material passing adjacent the shafts (fig.1), cannot snag upon, or become wrapped around, the shafts (fig.1). The mechanical material processing system may be a disc screen waste processing device.

Description

Anti-Wrapping Unit This invention is a system, comprising of new and standard components, the operation of the system eliminates the wrapping of material around a rotating part which cannot be protected by means of a fixed shaft as the rotation is part of the operational function. One of the systems applications would be in the material recovery process (recycling industry).

One of the machines the invention could be installed on would be a disc screen which, is a series of parallel shafts mounted at each end by fixed bearings. The shafts are driven at one end by a series of motors, with each motor driving a multiple number of shafts. Each shaft has discs mounted across its length at specified distances. The discs are mounted by sliding them onto the shaft with shrouds regulating the distance between discs.

Every other shaft has an offset disc pattern to allow the disc to run inside the spaces of the previous shafts discs when the shafts rotate. Disc screens are utilised in the separation of household and commercial waste in a material recovery facility. When the screen is operational waste is carried over the screen by the rotation of the discs, different types of waste will be carried over the screen to be processed whilst others will fall through onto a lower conveyor where the waste will be carried and processed in another part of the facility.

* : Due to the shafts rotating at approximately 2500 rpm waste such as film) textiles and plastic have a *....: high tendency of rapping around the shrouds. Once material has wrapped around the shrouds it is * necessary to de-activate the disc screen in order for a human operative to access the shrouds and remove the wrapped material. The material wrapping around the shrouds increases the likelihood of S...

: damage, wear and impeded operation of disc screen.

ro overcome the problem, the present invention proposes an anti-wrapping system. The design allows it to be attached to the shafts of the disc screen, an new shroud which replaces the existing * shrouds is slid along the shafts between the discs, an idle roller is fitted on a tension unit below the * . shafts at a said distance and the angle at which the centre line is taken can vary, and a belt which : runs around the shroud/s and the idle roller. The belt removes the ability of the material to wrap around the shroud as it will be carried onto the conveyor belt below. The addition of the system will eliminate the need to de-activate the screen for cleaning and will reduce the risk of damage and wear to the parts of the disc screen and improve the ojeration of the disc screen.

The invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 shows a shaft Figure 2 shows a belt Figure 3 shows the mountable disc Figure 4 shows the shroud FigureS shows a tensioning unit Figure 6 shows the idle roller Figure 7 shows the belt fitted around the shroud and idle roller In figure 1, the shaft is one of a series of shafts from inside the disc screen which the discs and shrouds are fitted to. rhis is one type of shaft that the system may be attached to.

In figure 2, the belt is a specialist belt selected for the application described.

In figure 3, the mountable disc is one of standard size and shape.

In figure 4, the shroud consists of a cylindrical tube of said length (dependent upon the disc spacing), at either end of the tube is a plate cut with an interference fit to the inside diameter of the cylindrical tube, the plate is set in slightly from the end of the cylindrical tube. In the centre of the plate is a cut out of the profile of the shaft, the profile is also cut with an interference fit to the shaft in order to eliminate any slipping which may be caused by the belt in figure 2 slipping on the outside edge of the shroud.

The plate set in at either end of the cylindrical tube allows for a stable balance across the shroud eliminating any pivot effect which may occur once the shroud rotates on the shaft which eliminates damage to the shaft.

Constructing the shroud in such a manner means that the weight of the shroud is minimal and does not add unnecessary extra weight to the shaft. The plates set inside the cylindrical tube with an interference fit to the shaft add stability to the shaft when rotational.

* The shroud is lagged on its outside face with rubber, the rubber has a nobble' effect to aid drivability and to reduce slippage of the belt in figure 2, when it runs around the outside of the : shroud.

In figure 5, the idle roller has with 2 welded solid stub shafts at either end. The roller has integral (internal) bearings. The stub shafts are fixed (non-rotational) and the roller rotates on the fixed stub * shafts, eliminating the risk of material wrapping around the rotating parts. The rollers diameter is less than half of the diameter of the shroud in figure 4, this creates a V' effect when the belt in * .: figure 2 is fitted. The belt will have a larger circumference around the shroud and V-ing' (necking) down around the idle roller. This assists the drivability of the belt and also means that the material ejected by the belt when it runs over the shroud should not fall onto the lower idle roller.

In figure 6, a multi tension unit which can carry up to five idle rollers and will locate the rollers at the same centre point as their corresponding shafts. The tension unit consists of a U' channel where a hole is made squarely through the two side walls of the U' channel and repeated at corresponding centre points to the shafts. Tension is applied by means of a threaded rod through the side walls of the channel and on one end of the threaded rod is a piece of box section where the stub shaft of the idle roller in figures is bolted through. The tension is applied by winding a nut against the opposite side wall to the one carrying the roller.

In figure 7 the mountable disc in figure 2 is mounted on the shaft in figure 1. The apela shroud' in figure 4 is fitted to the shaft in figure 1 between the mountable discs. The belt in figure 2 is fitted around the shroud and the idle roller in figure 6 which is mounted on the tension plate in figure 5.

Claims (2)

1. CLAIMS1. An Anti-Wrapping Unit comprising attachment means for attaching to the shafts of a disc screen, the operation of the system eliminates the wrapping of material around a rotating part which cannot be protected by means of a fixed shaft as the rotation is part of the operational function.
2. 2. An Anti-Wrapping Unit which removes the need to de-activate the disc screen in order for a human operative to access the shrouds and remove the wrapped material.