GB2145008A

GB2145008A - Apparatus for removing liquids from slurries

Info

Publication number: GB2145008A
Application number: GB08420998A
Authority: GB
Inventors: David Alan Brookes
Original assignee: BP PLC
Current assignee: BP PLC
Priority date: 1983-08-18
Filing date: 1984-08-17
Publication date: 1985-03-20
Also published as: GB8322275D0; GB8420998D0

Abstract

Apparatus for the removal of liquid from a slurry of solid particles in a liquid comprises (a) an elongated internal tubular chamber 2 for the passage of slurry, the walls of the chamber being permeable to liquid, (b) an external annular chamber 4 surrounding the internal chamber 2, for receiving the permeated liquid and (c) an outlet or outlets 6, 7 from the external annular chamber 4. The apparatus is particularly suitable for fitting to the end of a pipeline 1 to dewater slurries of coal in water. <IMAGE>

Description

SPECIFICATION Apparatus for removing liquids from slurries This invention relates to apparatus for removing liquid material from a slurry and more particularly to apparatus for removing water from an aqueous slurry containing mineral particles.

Several proposals have been made for the transportation of coal by preparing slurries of particles of coal in water and pumping the slurries through pipelines.

Our copending European patent application no 8330266.9 discloses a pumpable slurry of mineral particles in water comprising coarse mineral particles having a particle size in the range 5 to 50 mm and fine mineral particles having a size less than 200 micron wherein the slurry contains 50 to 85% by weight of mineral particles based on the combined weight of mineral particles and water, at least 30% by weight of the mineral particles being in the form of coarse particles, 10 to 40% by weight being in the form of fine particles and the balance to 100% by weight being intermediate sized particles.

In order to use or treat the mineral particles after transportation it is frequently necessary to remove at least some of the liquid associated with the solid particles in the slurry.

According to the present invention there is provided apparatus for the removal of liquid from a slurry of solid particles in a liquid which apparatus comprises (a) an elongated internal tubular chamber for the passage of slurry, the walls of the chamber being permeable to liquid, (b) an external annular chamber surrounding the internal chamber, for receiving the permeated liquid and (c) an outlet or outlets from the external annular chamber.

A limited amount of fines may permeate with the liquid.

Preferably the external chamber is divided into at least two non-communicating sections with outlet(s) from each or every section.

Preferably a plurality of outlets are provided from each section equidistantly spaced across a section of the chamber.

Preferably the internal chamber is supported by support rings mounted in the external chamber which permit the passage of liquid.

The internal chamber may be constructed from a series of wire mesh screens. Alternatively, and preferably for large scale operation, the chamber may be constructed from a wedge wire screen rolled into a tube. A wedge wire screen consists essentially of a number of tapered wire rods lying parallel to one another and fixed to supports, at least at their ends.

The apparatus may be used in connection with a pipeline carrying a slurry of mineral particles in water according to European patent application No 8330266.9 and the diameter of the internal chamber should in that case correspond to the internal diameter of the pipepline.

It is believed that in motion the fine particles concentrate at the wall of the pipeline and the coarse particles at the core. The fines at the pipeline wall act-as- a lubricant for the coarse particles at the core. When the slurry reaches the apparatus, the annular layer bleeds off initially up to the point where a high back pressure builds up sufficient to force out the water and possibly some fines.

The invention is illustrated with reference to Figs. 1 and 2 of the accompanying drawings wherein Fig. 1 is a sectional elevation of a coal dewatering device and Fig. 2 is an end elevation. For ease of representation, Fig. 1 has been divided into Fig. 1A and Fig. 1 B which should be viewed as adjoining.

The device is connected to the end of a coal water slurry pipeline 1. It comprises an internal chamber 2 formed by layers of wire mesh supported on a backing screen. The internal chamber 2 is surrounded by an outer shell 3 providing an annulus 4 between them.

The slurry emerges from the pipeline 1 and into the dewatering device. As it progresses along the latter water permeates through the wall of the chamber 2 and into the annulus 4.

Eventually a slurry with a relatively high content of coal and low content of water is discharged from the outlet 5.

Water passing into the annulus 4 is discharged from it by three nozzles 6 and three nozzles 7 equidistantly situated along a cross section of the outer shell 3 and connected to manifolds 8.

The annulus 4 is divided into two noncommunicating sections by a full bore support ring 9. The internal chamber 2 is further supported by partial bore support rings 10 having channels to permit the flow of liquid.

1. Apparatus for the removal of liquid from a slurry of solid particles in a liquid which apparatus comprises (a) an elongated internal tubular chamber for the passage of slurry, the walls of the chamber being permeable to liquid, (b) an external annular chamber surrounding the internal chamber, for receiving the permeated liquid and (c) an outlet or outlets from the external annular chamber.

2. Apparatus according to claim 1 wherein the external chamber is divided into at least two non-communicating sections with outlets from each or every section.

3. Apparatus according to claim 2 wherein a plurality of outlets are provided from each section equidistantly spaced across a section of the chamber.

4. Apparatus according to any of the preceding claims wherein the internal chamber is supported by support rings mounted in the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Apparatus for removing liquids from slurries This invention relates to apparatus for removing liquid material from a slurry and more particularly to apparatus for removing water from an aqueous slurry containing mineral particles. Several proposals have been made for the transportation of coal by preparing slurries of particles of coal in water and pumping the slurries through pipelines. Our copending European patent application no 8330266.9 discloses a pumpable slurry of mineral particles in water comprising coarse mineral particles having a particle size in the range 5 to 50 mm and fine mineral particles having a size less than 200 micron wherein the slurry contains 50 to 85% by weight of mineral particles based on the combined weight of mineral particles and water, at least 30% by weight of the mineral particles being in the form of coarse particles, 10 to 40% by weight being in the form of fine particles and the balance to 100% by weight being intermediate sized particles. In order to use or treat the mineral particles after transportation it is frequently necessary to remove at least some of the liquid associated with the solid particles in the slurry. According to the present invention there is provided apparatus for the removal of liquid from a slurry of solid particles in a liquid which apparatus comprises (a) an elongated internal tubular chamber for the passage of slurry, the walls of the chamber being permeable to liquid, (b) an external annular chamber surrounding the internal chamber, for receiving the permeated liquid and (c) an outlet or outlets from the external annular chamber. A limited amount of fines may permeate with the liquid. Preferably the external chamber is divided into at least two non-communicating sections with outlet(s) from each or every section. Preferably a plurality of outlets are provided from each section equidistantly spaced across a section of the chamber. Preferably the internal chamber is supported by support rings mounted in the external chamber which permit the passage of liquid. The internal chamber may be constructed from a series of wire mesh screens. Alternatively, and preferably for large scale operation, the chamber may be constructed from a wedge wire screen rolled into a tube. A wedge wire screen consists essentially of a number of tapered wire rods lying parallel to one another and fixed to supports, at least at their ends. The apparatus may be used in connection with a pipeline carrying a slurry of mineral particles in water according to European patent application No 8330266.9 and the diameter of the internal chamber should in that case correspond to the internal diameter of the pipepline. It is believed that in motion the fine particles concentrate at the wall of the pipeline and the coarse particles at the core. The fines at the pipeline wall act-as- a lubricant for the coarse particles at the core. When the slurry reaches the apparatus, the annular layer bleeds off initially up to the point where a high back pressure builds up sufficient to force out the water and possibly some fines. The invention is illustrated with reference to Figs. 1 and 2 of the accompanying drawings wherein Fig. 1 is a sectional elevation of a coal dewatering device and Fig. 2 is an end elevation. For ease of representation, Fig. 1 has been divided into Fig. 1A and Fig. 1 B which should be viewed as adjoining. The device is connected to the end of a coal water slurry pipeline 1. It comprises an internal chamber 2 formed by layers of wire mesh supported on a backing screen. The internal chamber 2 is surrounded by an outer shell 3 providing an annulus 4 between them. The slurry emerges from the pipeline 1 and into the dewatering device. As it progresses along the latter water permeates through the wall of the chamber 2 and into the annulus 4. Eventually a slurry with a relatively high content of coal and low content of water is discharged from the outlet 5. Water passing into the annulus 4 is discharged from it by three nozzles 6 and three nozzles 7 equidistantly situated along a cross section of the outer shell 3 and connected to manifolds 8. The annulus 4 is divided into two noncommunicating sections by a full bore support ring 9. The internal chamber 2 is further supported by partial bore support rings 10 having channels to permit the flow of liquid. CLAIMS

4. Apparatus according to any of the preceding claims wherein the internal chamber is supported by support rings mounted in the external chamber which permit the passage of liquid.

5. Apparatus according to any of the preceding claims wherein the internal chamber is constructed from a wedge wire screen tube.

6. Apparatus as hereinbefore described with reference to Figs. 1 and 2 of the accompanying drawings.