US3848813A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Continuous process for mechanically separating materials contained in urban refuse
Assignee: United States Department of the Interior
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Filing: 1973-03-09
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Granted: 1974-11-19
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Expires: 1993-03-09
Abstract
Abstract Urban waste, such as that collected from households in urban areas, is processed in the dry ''''as collected'''' state to recover ferrous metals, nonferrous metals, glass and paper fractions of suitable quality for sale and recycling. Waste is first shredded without balling or crushing tin cans and is thereafter subjected to a series of separations based upon differences in the physical properties of the waste materials.
Inventors
- 👤 M Stanczyk
- 👤 P Sullivan
- 👤 M Spendlove
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:34
CPC Classifications
B; B03; B03B; B03B9/00; B03B9/06; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/52; Y10; Y10S; Y10S241/00; Y10S241/38
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
177 words
A process for the treatment of unburned urban refuse to separate and recover components thereof which comprises: a. Shredding the refuse to shatter glass objects while avoiding the balling up of metal cans; b. discharging the shredded product into a first pneumatic separation zone wherein light pieces of shredded refuse comprising paper and plastics are removed; c. subjecting the shredded refuse to a magnetic separation wherein a ferrous metal fraction comprising tin cans is removed; d. passing the refuse to an air classification zone and separating said portion into three fractions, a heavy fraction comprising massive metals, an intermediate fraction comprising glass, aluminum and heavy organic materials and a light fraction comprising paper and plastics; e. assorting the intermediate fraction by size to recover a small particle size fraction comprising glass and a large particle size fraction; f. comminuting the large particle size fraction and passing the comminuted product to a second pneumatic separation zone, and g. recovering from the second pneumatic separation zone a light fraction comprising paper and plastics and a heavy fraction comprising aluminum.
Claim 2
Dependent Claim
177 words
A process for the treatment of unburned urban refuse to separate and recover components thereof which comprises: a. Shredding the refuse to shatter glass objects while avoiding the balling up of metal cans; b. discharging the shredded product into a first pneumatic separation zone wherein light pieces of shredded refuse comprising paper and plastics are removed; c. subjecting the shredded refuse to a magnetic separation wherein a ferrous metal fraction comprising tin cans is removed; d. passing the refuse to an air classification zone and separating said portion into three fractions, a heavy fraction comprising massive metals, an intermediate fraction comprising glass, aluminum and heavy organic materials and a light fraction comprising paper and plastics; e. assorting the intermediate fraction by size to recover a small particle size fraction comprising glass and a large particle size fraction; f. comminuting the large particle size fraction and passing the comminuted product to a second pneumatic separation zone, and g. recovering from the second pneumatic separation zone a light fraction comprising paper and plastics and a heavy fraction comprising aluminum.
Claim 3
Dependent Claim
26 words
The process of claim 1 wherein light pieces of shredded refuse are removed from the first pneumatic separation zone in air suspension and are thereafter collected.
Claim 4
Dependent Claim
26 words
The process of claim 2 wherein said light fraction from the air classification zone is removed from that zone in air suspension and is thereafter collected.
Claim 5
Dependent Claim
27 words
The process of claim 3 wherein the light fraction from the second pneumatic separation zone is removed from that zone in air suspension and is thereafter collected.
Claim 6
Dependent Claim
49 words
The process oF claim 4 wherein the light fractions collected from the first pneumatic separation zone, the air classification zone and the second pneumatic separation zone are merged to form a combustible waste stream containing substantially all of the paper and light plastics present in the unburned urban waste.
Claim 7
Dependent Claim
16 words
The process of claim 5 wherein the combustible waste stream is burned to recover heat energy.
Claim 8
Dependent Claim
40 words
The process of claim 3 wherein the light shredded refuse collected from the first pneumatic separation zone is merged with the light fraction from the air classification zone and the combined fractions are thereafter subjected to an additional shredding step.
Claim 9
Dependent Claim
39 words
The process of claim 7 wherein the shredded fractions from the first pneumatic separation zone and the air classification zone are subjected to an electrodynamic separation to produce a paper fraction substantially free of plastics and a plastics fraction.
Claim 10
Dependent Claim
37 words
The process of claim 3 wherein the heavy fraction comprising massive metals recovered from the air classification zone is subjected to a second magnetic separation to recover a heavy iron fraction and a heavy, nonferrous metals fraction.
Claim 11
Dependent Claim
33 words
The process of claim 4 wherein the small particle size fraction obtained in the assorting step is further purified by water elutriation to recover a clean glass product and an organic waste fraction.
Claim 12
Dependent Claim
29 words
The process of claim 10 wherein the organic waste fraction is combined with the light fraction recovered from the second pneumatic separation zone to form a combustible waste fraction.
Claim 13
Dependent Claim
35 words
The process of claim 4 wherein the heavy fraction recovered from the second pneumatic separation zone is further purified by water elutriation to recover a clean product fraction comprising aluminum and an organic waste fraction.
Claim 14
Dependent Claim
29 words
The process of claim 12 wherein the organic waste fraction is combined with the light fraction recovered from the second pneumatic separation zone to form a combustible waste fraction.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |