Liquid purification or separation – Processes – Using magnetic force
Patent
1987-07-27
1989-05-09
Jones, W. Gary
Liquid purification or separation
Processes
Using magnetic force
55 3, 55100, 209214, 2092231, 2092232, 209232, 210222, B03C 108
Patent
active
048287113
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
This invention concerns magnetic separators and methods of use thereof. The invention applies to the separation of relatively magnetic and relatively non-magnetic materials which occur as particulate admixtures suspended in gaseous media. The invention further applies to the separation of such admixtures suspended in liquids, provided that sufficient magnetic force is available for overcoming fluid drag. The invention further applies to the separation of relatively magnetic fluids from relatively non-magnetic fluids. The invention further applies to the separation of particles from a fluid, if there is sufficient magnetic force for overcoming fluid drag and if there is sufficient difference in magnetic susceptibility, either the particles or the fluid exhibiting relatively higher magnetic susceptibility. The fluid may be a liquid, e.g. water or hydrocarbon compounds such as fuel oils, or it may be a suspension or an emulsion. The term "particle" as used above and throughout the specification refers to sizes ranging from sub-micrometres to several centimetres or more, unless particle size is more closely dictated in a specific context.
SUMMARY OF THE INVENTION
The invention, comprising apparatus design and method of separation, applies especially but not exclusively to the separation of particles bearing sulphur and iron impurities from pulverised coal. It is common practice to grind coal to fine sizes, typically below 200 micrometres, for combustion in electric power generation. The pulverised coal may be suspended in an air stream, or it may form a suspension in water or in fuel oil. In the pulverised coal, impurities such as waste stone, shale and iron sulphides occur as partly or fully liberated particles. One purpose of this invention is to enable such impurities to be removed as a magnetic reject, thus rendering cleaner coal for combustion, with higher calorific value and with lower sulphur content. The impurities can be removed by magnetic separation because typically they have higher magnetic susceptibilities than coal which is feebly diamagnetic. However, the magnetic susceptibilities of the impurities are generally weak and hence it is necessary to employ very strong magnetic forces. The preferred embodiment of this invention therefore employs a superconducting magnet so as to generate field strengths in excess of 2 Tesla. Normal copper coil magnets, or even permanent magnets may be used in other applications where the magnetic product may be of sufficiently high magnetic susceptibility. In general, stronger magnetic forces will permit higher rates of throughput for any given feed material.
According to the invention in its broadest aspect, separation is effected by feeding a stream of material containing relatively magnetic and relatively non-magnetic materials (hereinafter referred to simply as magnetic and non-magnetic materials) across at least one face of a solenoid coil magnet in a manner such as to cause the magnetic and non-magnetic materials to diverge during their passage past the magnet, and to be directed into separate collector channels.
The rate of feed and the magnetic force should, of course, be chosen such as to prevent magnetic material adhering to the magnet face or faces to any appreciable extent.
The solenoid coil magnet is conveniently associated with a duct through which the mixed material is fed at a controlled rate, the directional effects of the shape of the duct and the magnetic forces causing the divergence in the directions of travel of the non-magnetic and magnetic materials, such that they are directed into respective discharge channels from the duct.
Preferably the solenoid coil magnet is disposed in such a position within the duct that the stream of materials passes across the two faces of the solenoid coil magnet, so that the magnetic material is deflected both axially and radially inwards and passes to a central discharge channel, whilst the non-magnetic matrial passes to an outer discharge channel on each side of the solenoid.
Pre
REFERENCES:
patent: 263131 (1882-08-01), Edison
patent: 1103358 (1914-07-01), Hess
patent: 3608718 (1971-09-01), Aubrey et al.
patent: 3767545 (1973-10-01), Lucero
patent: 4478711 (1984-10-01), Cohen
Hise, E. C., IEEE Transactions on Magnetics, vol. Mag 18, No. 3, May, 1982, "Development of High Gradient . . . ".
GEC Mechanical Handling Limited
Jones W. Gary
LandOfFree
Method and apparatus for separating relatively magnetic and rela does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for separating relatively magnetic and rela, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for separating relatively magnetic and rela will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-88074