GB2163410A

GB2163410A - A particulate solids sampling system

Info

Publication number: GB2163410A
Application number: GB08421209A
Authority: GB
Inventors: Thomas Bernard Mccallum; Michael Roger Birch; Terrence Barry Sheen; John Keery
Original assignee: Coal Industry Patents Ltd
Current assignee: Coal Industry Patents Ltd
Priority date: 1984-08-21
Filing date: 1984-08-21
Publication date: 1986-02-26
Also published as: GB8421209D0; GB2163410B

Abstract

A batch of coal on a conveyor (2) is sensed by a material sensor unit (1) which signals a controller (not shown). The controller activates a pneumatic ram (4) whose attached scoop (3) moves transversely across the conveyor (2) taking a sample as it moves and depositing the sample into a collection hopper (6). When the ribbon of coal has passed the material sensor unit (1) signals the controller (not shown) which activates the ram (4) retracting it with its scoop (3). The controller may be programmed as to which batches of coal are sampled and where the sample is taken from within each batch. <IMAGE>

Description

SPECIFICATION A particulate solids sampling system This invention relates to a particulate solids sampling system In particularthis invention relates to a system for sampling particulate coal from a moving conveyor.

After coal has been mined it is necessary, before it can be sold, to process it through a coal preparation plant. In such a plant the coal may be crushed, washed, graded and sized according to the markets for which it is destined. The specification of coal for different markets is tightly controlled in terms of parameters such as, size range, calorific value, ash content, moisture content etc. To keep these parameters within specification it is necessary to sample the output coals from the preparation plant and perform various analyses on the product coal. The coal is generally transported between processes within a coal preparation plant by conveyor. It is therefore convenient to sample the coal from a suitable moving conveyor at a convenient point within the coal preparation plant.Commonly coal from a main stream may be periodically sampled onto a separate conveyor, this conveyor leading to sample preparation apparatus. In some coal preparation plants it is necessary to take a sample from this sampling conveyor for moisture analysis. As the flow of coal on this sampling conveyor is discontinuous it is not possible to use a simple sampling method.

It is an object of the present invention to provide a novel sampling system for sampling particulate solids from a belt type conveyor.

Accordingly the present invention provides a particulate solids sampling system for sampling solids from a belt type conveyor, comprising material sensor means arranged to detect the presence of solid material on a conveyor, scoop means connected to a drive ram arranged to traverse said scoop across the conveyor, collector means arranged to receive material from the scoop, and ram control means the system being arranged to operate such that when the material sensor detects the presence of solids on the conveyor it activates the ram control means which in turn operates the drive ram causing the scoop to move across the conveyor, scooping up a sample of the solids as it moves, and depositing the sample into the collector means.

Conveniently the collector means comprises a collection hopper with a gravity filled sample container below.

Conveniently there is a sealing valve between the collection hopper and the sample container whose status is controlled by the control means such that the valve is opened on activation of the drive ram and closed after the sample has dropped into the sample container.

The controller may be programmable with respect to all its control functions.

Preferably the controller may only be programm able with respect to; (1) Whether or not a sample will be taken upon receipt of a signal from the material sensor; and; (2) If a sample is to be taken, where, along the solids on the conveyor, the sample is to be taken from.

Conveniently the drive ram is double acting such that after sampling the ram and scoop can be withdrawn in readiness for the next sample.

Conveniently the material sensor means is positioned up stream of the drive ram, scoop and collector means, with respect to the direction of flow of material on the conveyor.

The present invention will now be described by way of example only with reference to the accompanying drawings in which; Figure 1 shows a plan view of a particulate solids sampling system according to the present invention and; Figure 2 shows a schematic diagram of the sampling system.

Referring now to the drawings the particulate solids sampling system comprises a material sensing unit I adjacent a belt conveyor 2. A sampling scoop 3 is mounted on the piston rod of a double acting pneumatic ram 4 and arranged, downstream of the materials sensing unit 1, also adjacent the conveyor 2.

Collector means comprised by a hopper 6 is mounted opposite the sampling scoop 3 (see Figure 1) and has below it a sealing valve 7 and sample container 8. (see Figure 2).

The double acting ram 4 and sealing valve 7 are both connected via pneumatic lines to a programmable controller 9. The material sensing unit 1 is also connected to the programmable controller 9 via an electrical line. Electricity and pressurised air are fed into the controller 9 via input lines 10 and 11 respectively. In use the system operates as follows; The conveyor 2 is a primary sampling device in a coal washery. It is fed a large sample of product coal at predetermined intervals thus a ribbon of coal periodically appears on it. When this occurs the material sensing unit 1 signals the programmable controller 9 that there is coal on the conveyor 2.The controller 9 then consults its programme, which has been previously loaded into the controller, as to whether or not this particular primary sample on conveyor 2 needs sampling and if so where along the ribbon of coal the sample needs to be taken.

Assuming a sample is to be taken the controller 9 signals the double acting pneumatic ram 4 to operate, at the same instant the controller 9 signals the sealing valve 7 to open. The ram 4 pushes the sampling scoop 3 across the carrying surface of the conveyor 2 thus removing a sample of the coal from the conveyor. The scoop 3 is pushed right over the collection hopper 6 and, the scoop 3 having no bottom, the coal sample drops into the collection hopper 6, through the open sealing valve 7 and finally into the sample container 8. When the primary sample of coal has moved the past sampling system the material sensor unit 1 signals the controller 9 and the controller 9, in turn, signals the ram 4 to retreat and sealing valve 7 to close. In this way a sample of coal is taken from the conveyor 2 and stored in a sealed vessel, to prevent sample de terioration, entirely automatically.

The sampling system may be used in any process involving transport of particulate solids on conveyors. If used to sample a continuous flow of solids provision must be made for the retraction of the ram and scoop through the solids.

Claims

1. A particulate solids sampling system for sampling solids from a belttype conveyor, comprising material sensor means arranged to detect the presence of solid material on a conveyor, scoop means connected to a drive ram arranged to traverse said scoop across the conveyor, collector means arranged to receive material from the scoop, and ram control means, the system being arranged to operate such that when the material sensor detects the presence of solids on the conveyor it activates the ram control means which in turn operates the drive ram causing the scoop to move across the conveyor, scooping up a sample of the solids as it moves, and depositing the sample into the collector means.

2. A sampling system according to claim 1, wherein the collector means comprises a collection hopper with a gravity filled sample container below.

3. A sampling system according to claim 2, wherein there is a sealing valve between the collection hopper and the sample container whose status is controlled by the control means such that the valve is opened on activation of the drive ram and closed after the sample has dropped into the sample container.

4. A sampling system according to any of the preceding claims, wherein the controller is programmable in respect of all its control functions.

5. A sampling system according to claim 4, wherein the controller is only programmable with respect to (1 ) whether or not a sample will be taken upon receipt of a signal from the material sensor and (2) if a sample is to be taken, where, along the solids on the conveyor the sample is to be taken from.

6. A sampling system according to any of the preceding claims, wherein the drive ram is double acting such that after sampling the ram and scoop can be withdrawn in readiness for the next sample.

7. A sampling system according to any of the preceding claims, wherein the material sensor means is positioned upstream of the drive ram, scoop and collector means, with respect to the direction of flow of material on the conveyor.

8. A particulate solids sampling system substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.