GB2096085A

GB2096085A - A system for transporting coal for charging into coking ovens

Info

Publication number: GB2096085A
Application number: GB8207655A
Authority: GB
Original assignee: Otto Simon Carves Ltd; Carves Simon Ltd
Current assignee: Otto Simon Carves Ltd; Carves Simon Ltd
Priority date: 1981-04-01
Filing date: 1982-03-16
Publication date: 1982-10-13
Also published as: IT1150511B; GB2096085B; IT8220542A0; NL8201388A; DE3211426A1; FR2503107A1; FR2503107B1

Abstract

A system for transporting dried and preheated coal into a battery of coking ovens (16), comprising a charge bin (10) which receives coal to a desired level, means (20) for injecting into the charge bin a gas or vapour to establish therein a conveying pressure, a pipeline (14) extending from a valved outlet (13) of the charge bin to the coking oven chambers to be charged and means (21) for injecting the gas or vapour into the pipeline at spaced positions therealong to maintain the conveying pressure therein, the system in use serving to transport coal throughout the pipeline as a dense phase wherein the ratio of solids to conveying medium in the pipeline is maintained greater than 750:1 by weight. <IMAGE>

Description

SPECIFICATION A system for transporting coal for charging into coking ovens This invention concerns the charging of coking ovens with coal, and particularly, a method and apparatus for transporting the coal in an enclosed pipeline towards the individual ovens of a coking oven battery, as a dense phase, i.e. where the ratio of solids to conveying medium is maintained greater than 750:1 by weight.

It is known to transport coal to coking ovens in a lean phase, i.e. by dispersing it in a stream of high velocity, low pressure conveying medium such as superheated steam.

Thus, a considerable volume of steam is injected into the pipeline at a number of spaced positions in order to keep the coal finely dispersed in the conveying stream, and this results in a number of disadvantages. For example, the cost of maintaining the high volume of carrier medium is excessive. The high velocity of the system causes the coal particles to be reduced and degraded, and the collision of the coal particles with the walls of the pipeline causes rapid wear of the system.

Also, it is necessary to prevent the considerable volume of steam entering the oven, and so means must be provided for extracting a large volume of the steam from the pipeline at positions close to its entry into the ovens.

An object of the present invention is to provide a system for charging coal into a battery of coking ovens, wherein the aforementioned disadvantages are at least substantially avoided.

According to the present invention, there is provided a system for transporting coal to be charged into a battery of coking ovens, comprising a charge bin in which the coal is stored, a pipeline extending from the outlet of the charge bin towards a plurality of coal charging positions adjacent the coke ovens, means for injecting a gas or vapour into the charge bin to establish therein a conveying pressure, means for injecting said gas or vapour into the pipeline at a plurality of spaced positions along the length thereof to maintain said conveying pressure, and valve means for releasing the coal from the charge bin as a mass substantially filling the pipeline or a part thereof, such that the coal is transported substantially throughout said pipeline as a dense phase wherein the ratio of solids to gas or vapour in the pipeline is maintained greater than 750:1 by weight.

Further, according to the invention, there is provided a method of transporting coal to be charged into a battery of coke ovens, comprising the steps of storing the coal in a charge bin, injecting a gas or vapour into the charge bin to establish therein a conveying pressure, releasing the coal from the charge bin into a pipeline extending from an outlet of the charge bin towards a plurality of coal charging positions adjacent the coking ovens, said coal being released into said pipeline as a mass substantially filling the latter or a part thereof, and injecting said gas or vapour into the pipeline at a plurality of spaced positions along the length thereof thus to maintain said conveying pressure therein, whereby the coal is transported substantially throughout said pipeline as a dense phase wherein the ratio of solids to gas or vapour in the pipeline is maintained greater than 750:1 by weight.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying schematic drawing which illustrates a charging system for pre-heated coal.

Referring now to the drawings there is provided a charge bin 10 mounted on load cells 1 ova, and adapted to receive pre-heated coal from a pre-heating system (not shown) via an input line 11. The base of the charge bin 10 is formed as a hopper 1 2 which has an outlet at its base and a valve 1 3 to control the flow of coal from the bin.

A continuous pipeline 14 connects the valve 1 3 to a number of branch pipes 1 5 at charging positions above a battery 1 6 of coking ovens. The pipeline can include, if necessary, a vertical or upwardly inclined section and preferably is downwardly inclined in a portion 1 4a above the battery, to assist the flow of material therein.

A supply of superheated steam is introduced via a line 20 which is connected to the charge bin 10 and to a plurality of inlet points 21 spaced along the length of the pipeline 14. A conventional system of valves and regulators (not shown) forming no part of the present invention is provided in the usual way to control the introduction of the steam into the charge bin and the pipeline at the various positions, and the pressure at which the steam is introduced.

In use, the charge bin 10 is filled with preheated coal to a desired level which is detected by the load cells 1 ova. Superheated steam is introduced into the bin until a conveying pressure in the region of 1 5 to 100 p.s.i.g. is established.

When valve 1 3 is opened the coal is forced into the pipeline 14 by the pressurised steam in the bin, and induced to flow along athe pipe as a substantially integral mass, towards the oven chambers to be charged. The further introduction of steam at the spaced positions 21 along the length of the pipe 14, serves to maintain the required conveying pressure in the pipe.

The establishment of a dense phase charging system wherein the ratio of solids to steam is in the range of 750:1 to 2000:1 by weight, when compared with lean phase charging where the particles are accelerated into a steam of high velocity carrier gas or vapour and the solids to gas ratio can be 100:1 by weight or less, ensures a considerably increased charging rate and improves the bulk density of the charge in the oven. The increased charging rate in turn enhances the self levelling characteristics of the coal upon entering the oven thus producing a more uniform charge.

The low proportion of carrier steam in the pipeline avoids the need for a deliberate takeoff of steam from the pipe prior to its entry into the oven, and the general reduction in the quantity of steam entering the oven reduces the effect of coal dust being carried over into the gas collecting mains associated with the battery.

The system is not restricted to use for transporting pre-heated coal, and may be used for otherwise dried coal, or even coal in a moist condition.

It is envisaged that the coal transported by pipeline towards the coking ovens can be either fed direct to the ovens or stored or bunkered adjacent to the oven battery and delivered to the ovens via a charge car, screw conveyor or the like.

Claims

1. A system for transporting coal to be charged into a battery of coking ovens, comprising a charge bin in which the coal is stored, a pipeline extending from the outlet of the charge bin towards a plurality of coal charging positions adjacent the coke ovens, means for injecting a gas or vapour into the charge bin to establish therein a conveying pressure, means for injecting said gas or vapour into the pipeline at a plurality of spaced positions along the length thereof to maintain said conveying pressure, and valve means for releasing the coal from the charge bin as a mass substantially filling the pipeline or a part thereof, such that the coal is transported substantially throughout said pipeline as a dense phase wherein the ratio of solids to gas or vapour in the pipeline is maintained greater than 750:1 by weight.

2. A system according to Claim 1, wherein said charge bin includes means for detecting the level of coal therein.

3. A system according to Claim 1 or Claim 2 wherein said pipeline includes a vertical section.

4. A system according to Claim 1 or Claim 2, wherein said pipeline includes an upwardly inclined section.

5. A system according to any preceding claim, wherein the pipeline is continuous and connects the charge bin to a plurality of branch pipes at charging positions above the coking ovens thus to enable transport of the coal from the charge bin directly into the oven chambers to be charged.

6. A system according to Claim 5, wherein said continuous pipeline includes a section inclined downwardly above the coking ovens to assist the flow of coal thereto.

7. A system according to Claim 2, wherein said detecting means comprises one or more load cells upon which the charge bin is mounted.

8. A system according to any preceding claim, wherein said means for injecting said gas or vapour into the charge bin is adapted to establish therein a conveying pressure in the region of 1 5 to 100 p.s.i.g.

9. A method of transporting coal to be charged into a battery of coke ovens, comprising the steps of storing the coal in a charge bin, injecting a gas or vapour into the charge bin to establish therein a conveying pressure, releasing the coal from the charge bin into a pipeline extending from an outlet of the charge bin towards a plurality of coal charging positions adjacent the coking ovens, said coal being released into said pipeline as a mass substantially filling the latter or a part thereof, and injecting said gas or vapour into the pipeline at a plurality of spaced positions along the length thereof thus to maintain said conveying pressure therein, whereby the coal is transported substantially throughout said pipeline as a dense phase wherein the ratio of solids to gas or vapour in the pipeline is maintained greater than 750:1 by weight.

10. A method according to Claim 9, wherein said conveying pressure is established in the region of 15 to 1000 p.s.i.g.

11. A method according to Claim 9 or Claim 10, wherein in a section or said pipeline, said mass of coal is transported upwardly.

1 2. A method according to any one of Claims 9 to 11, wherein the coal is maintained in said charge bin until it attains therein a desired level, whereupon a valve is opened to release the coal into said pipeline.

1 3. A method according to any one of Claims 9 to 12, wherein said gas or vapour is superheated steam and is transported directly into the oven chambers along with said coal.

14. A method according to any one of Claims 9 to 12, wherein said coal, after transportation in said pipeline, is stored or bunkered prior to delivery into said coking ovens.

1 5. A system for transporting coal to be charged into a battery of coking ovens, substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawing.