Liquid purification or separation – Processes – Using magnetic force
Reexamination Certificate
2001-05-21
2003-02-04
Savage, Matthew O. (Department: 1723)
Liquid purification or separation
Processes
Using magnetic force
C210S748080, C210S772000
Reexamination Certificate
active
06514417
ABSTRACT:
The present invention relates generally to treatment of industrial wastes, and more particularly to microwave assisted cleaning and reclamation of oily metallic industrial wastes.
BACKGROUND OF THE INVENTION
Several industrial processes produce oily mixed wastes. One example is hot strip rolling steel mills. Cooling water from these mills generally contains oily metallic particles. Typical treatment processes for these wastes use tanks and chemicals for flocculating, settling, thickening, de-watering, and stiffening to produce concentrated waste sludge.
FIG. 1
shows a block diagram of a typical treatment plant for processing oily cooling water from a hot strip rolling mill. The waste effluent enters a rapid mix tank
20
, as shown by arrow
22
, where it is mixed with an anionic polymer. From there, it proceeds through conduits
24
to clarifying tanks
26
, as shown by arrows
25
, where oil is skimmed off, as shown by arrows
28
, and water is removed, as shown by arrows
30
, and directed to a wet well
32
. From the wet well
32
, the water is directed through pressure filters
34
, a cooling tower
36
, and into a cold well
38
, as shown by arrows
33
,
35
and
37
, to provide a source of cooling water for the mill again.
The remaining waste
39
from the clarifying tanks
26
is directed through conduits
40
to thickening tank
42
, as shown by arrows
41
, where anionic and/or cationic polymers, and/or sulfuric acid are added. The thickened waste
44
is then directed through conduit
46
to drum filter
48
, as shown by arrow
47
, and finally deposited as a waste sludge cake in receptacle
50
, as shown by arrow
49
.
The sludge volume is typically approximately ⅓ water, ⅓ oil, and ⅓ iron metal and iron oxides, to which lime is added for stiffening. The waste sludge is typically disposed of in a special landfill or trucked to a special processing plant external to the producing, company.
A typical hot strip rolling mill can generate 50 tons of sludge per day and more than 7,000 tons per year. The costs associated with production and disposal of this sludge are significant.
Moreover, conventional water treatment processes are time consuming, and plant equipment is very bulky, requiring extensive housing space at mill facilities. Also, as land fills reach capacity, the cost of disposal of mill waste sludge can be expected to increase.
Accordingly, there is a need for faster, smaller and more economical industrial waste water treatment systems.
There are many known processes for the separation of oil and water emulsions. These processes are commonly referred to as emulsion cracking. Emulsion cracking typically needs the addition of heat and frequently requires deemulsifying chemical agents. Processing times using gravity settling methods often require 4 to 24 hours for better than 90% separation.
Recently, oil/water emulsion cracking systems using microwave energy have been successfully field tested and are currently being developed, mainly for the petroleum industry. Microwave emulsion cracking systems are compact and have demonstrated rapid, continuous, processing at flow rates to beyond 50 gallons-per-minute (gpm), through the use of flow through microwave applicators. Efficient microwave processing typically requires only a 20° C. process temperature rise and uses power, for example, at an 8 to 12 kilowatts per gallon per minute (kW/gpm)power processing rate. For some applications, microwave emulsion cracking has the added benefit of not requiring the addition of chemicals.
While these methods may improve the separation of oil-water emulsions, they do not address the distinct problem of additionally separating oil from metallic solids frequently present in industrial waste effluents, such as cooling water from hot strip rolling mills. Accordingly, it is an object of the present invention to provide a method for treating industrial wastes containing oily metallic solids by separating a waste into its various components for reclamation and reuse, thereby significantly reducing or eliminating waste sludge. It is also an object of the present invention to provide waste water treatment process equipment that is faster and more compact than that presently typically used.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the claims.
The present invention provides a process and apparatus for cleaning and reclamation of an industrial waste containing oily metallic solids by magnetically concentrating the oily magnetic solids, mixing the concentrated solids with a chemical release agent, applying microwave radiation to the mixture, and separately collecting the clean metallic solids and recovered oil components.
REFERENCES:
patent: 4582629 (1986-04-01), Wolf
patent: 4810375 (1989-03-01), Hudgins et al.
patent: 4853119 (1989-08-01), Wolf et al.
patent: 4853507 (1989-08-01), Samardzija
patent: 4855695 (1989-08-01), Samardzija
patent: 4889639 (1989-12-01), Hudgins et al.
patent: 5147554 (1992-09-01), Heck
patent: 5785847 (1998-07-01), Purta et al.
patent: 12905 (1978-05-01), None
patent: 53-12905 (1978-06-01), None
patent: 59-115716 (1982-12-01), None
Guzman Alberto M.
Purta David A.
Electric Power Research Institute Inc.
Fish & Richardson P.C.
Savage Matthew O.
LandOfFree
Microwave assisted cleaning and reclamation of industrial... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Microwave assisted cleaning and reclamation of industrial..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Microwave assisted cleaning and reclamation of industrial... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3124242