US3913500A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat treatment of waste sludges
Assignee: Chicago Bridge and Iron Co
•
Filing: 1974-05-01
•
Granted: 1975-10-21
•
Expires: 1994-05-01
Abstract
Abstract The present invention relates to the disposal of sewage sludges or the like, by thermally conditioning the sludges, dewatering the sludges and subsequently incinerating the organic content of the sludges. More particularly the present invention is directed to a waste disposal process which employs the heat from the incineration step to condition the sludges, followed by dewatering the conditioned sludge in order to form a supraautogeneous feed to the incinerator.
Inventors
- 👤 James Dennis Paccione
- 👤 David Moore O'meara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:30
CPC Classifications
F; F23; F23G; F23G7/00; F23G7/001; B; B01; B01J; B01J8/00; B01J8/18; B01J8/24; C; C02; C02F; C02F11/00; C02F11/12; C02F11/13
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
127 words
A METHOD OF INCINERATING HIGH MOISTURE SEWAGE SLUDGE WHICH COMPRISES: PROVIDING A COMBUSTION CHAMBER CONTAINING A BODY OF HOT INERT GRANULAR MATERIAL HAVING HEAT-STORING AND HEAT RADIATING CAPABILITY, SUPPLYING AN OXYGEN CONTAINING FLUIDIZING GAS TO SAID GRANLAR MATERIAL IN ORDER TO FROM A FLUIDIZED BED THEREOF, CONTINULOSLY FEEDING HIGH MOISTURE SEWAGE SLUDGE THROUGH A HEAT EXCHANGE MEANS LOCATED IN HEAT EXCHANGE RELATIONSHIP WITH SAID FLUIDIZED BED,WHEREBY SAID SLUDGE IS HEATED TO AN ELEVATED TEMPERATURE AND AN ELEVATED PRESSURE, HOLDING SAID HEATED SLUDGE AT AN ELEVATED TEMPERATURE AND AN ELEVATED PRESSURE FOR A TIME SUFFICIENT TO PERMIT EFFECTIVE CONDITIONING, DEWATERING SAID CONDITIONED SLUDGE TO RAISE THE SOLIDS LEVEL TO AT LEAST 10 PERCENT BY WEIGHT, FEEDING SAID DEWATERED SLUDGE INTO SAID FLUIDIZED BED, WHEREIN SAID SLUDGE IS INCINERATED.
Claim 2
Independent Claim
127 words
A METHOD OF INCINERATING HIGH MOISTURE SEWAGE SLUDGE WHICH COMPRISES: PROVIDING A COMBUSTION CHAMBER CONTAINING A BODY OF HOT INERT GRANULAR MATERIAL HAVING HEAT-STORING AND HEAT RADIATING CAPABILITY, SUPPLYING AN OXYGEN CONTAINING FLUIDIZING GAS TO SAID GRANLAR MATERIAL IN ORDER TO FROM A FLUIDIZED BED THEREOF, CONTINULOSLY FEEDING HIGH MOISTURE SEWAGE SLUDGE THROUGH A HEAT EXCHANGE MEANS LOCATED IN HEAT EXCHANGE RELATIONSHIP WITH SAID FLUIDIZED BED,WHEREBY SAID SLUDGE IS HEATED TO AN ELEVATED TEMPERATURE AND AN ELEVATED PRESSURE, HOLDING SAID HEATED SLUDGE AT AN ELEVATED TEMPERATURE AND AN ELEVATED PRESSURE FOR A TIME SUFFICIENT TO PERMIT EFFECTIVE CONDITIONING, DEWATERING SAID CONDITIONED SLUDGE TO RAISE THE SOLIDS LEVEL TO AT LEAST 10 PERCENT BY WEIGHT, FEEDING SAID DEWATERED SLUDGE INTO SAID FLUIDIZED BED, WHEREIN SAID SLUDGE IS INCINERATED.
Claim 3
Dependent Claim
23 words
A method, as described in claim 1, wherein said high moisture sludge contains from about 1 to about 8 percent solids, by weight.
Claim 4
Dependent Claim
21 words
A method, as described in claim 1, wherein said bed is maintained at a temperature of from about 650* to 980*C.
Claim 5
Dependent Claim
26 words
A method, as described in claim 1, wherein the residence time of said sludge in said heat exchange means is no more than about 25 seconds.
Claim 6
Dependent Claim
27 words
A method, as described in claim 1, wherein said sludge passes through said heat exchange means at a velocity between about 0.3 and 3.0 meters per second.
Claim 7
Dependent Claim
30 words
A method, as described in claim 1, wherein said sludge in said heat exchange means is heated at a pressure high enough to avoid flashing in said heat exchange means.
Claim 8
Dependent Claim
17 words
A method, as described in claim 1, wherein said conditioning temperature is between about 180* and 220*C.
Claim 9
Dependent Claim
19 words
A method, as described in claim 1, wherein said heated sludge is conditioned for between 30 and 90 minutes.
Claim 10
Dependent Claim
20 words
A method, as described in claim 1, wherein said dewatered sludge has a solids content of at least 30 percent.
Claim 11
Dependent Claim
15 words
A method, as described in claim 1, wherein said conditioned sludge is dewatered by sedimentation.
Claim 12
Dependent Claim
15 words
A method, as described in claim 1, wherein said conditioned sludge is dewatered by filtration.
Claim 13
Dependent Claim
15 words
A method, as described in claim 1, wherein said conditioned sludge is dewatered by centrifugation.
Claim 14
Independent Claim
121 words
AN APPARATUS FOR HEAT TREATMENT AND INCINERATION OF HIGH MOISTURE SEWAGE SLUDGES CONTAINING FROM ABOUT 1 TO ABOUT 8 PERCENT SOLIDS WHICH COMPRISES: A FLUIDIZED-BED REACTOR HAVING HEAT EXCHANGE MEANS THEREIN, SAID HEAT EXCHANGE MEANS ADAPTED TO CONTINUOUSLY HEAT HIGH MOISTURE SLUDGE TO ELEVATED TEMPERATURES AND ELEVATED PRESSURES, MEANS TO HOLD SAID SLUDGE AT ELEVATED TEMPERATURES AND ELEVATED PRESSURES FOR A TIME SUFFICIENT TO EFFECTIVELY CONDITION SAID HIGH MOISTURE SLUDGE, SEWATERING MEANS IN FLUID COMMUNICATION WITH SAID SLUDGE HOLDING MEANS, SAID DEWATERING MEANS ADAPTED TO RAISE THE SOLIDS LEVEL OF SAID CONDITIONED SLUDGE TO AT LEAST 10 PPERCENT BY WEIGHT, AND MEANS TO CONTINUOUSLY FEED SAID DEWATERED SLUDGE TO THE REACTION ZONE OF SAID FLUIDIZED BED WHEREBY SAID SLUDGE IS INCINERATED.
Claim 15
Independent Claim
121 words
AN APPARATUS FOR HEAT TREATMENT AND INCINERATION OF HIGH MOISTURE SEWAGE SLUDGES CONTAINING FROM ABOUT 1 TO ABOUT 8 PERCENT SOLIDS WHICH COMPRISES: A FLUIDIZED-BED REACTOR HAVING HEAT EXCHANGE MEANS THEREIN, SAID HEAT EXCHANGE MEANS ADAPTED TO CONTINUOUSLY HEAT HIGH MOISTURE SLUDGE TO ELEVATED TEMPERATURES AND ELEVATED PRESSURES, MEANS TO HOLD SAID SLUDGE AT ELEVATED TEMPERATURES AND ELEVATED PRESSURES FOR A TIME SUFFICIENT TO EFFECTIVELY CONDITION SAID HIGH MOISTURE SLUDGE, SEWATERING MEANS IN FLUID COMMUNICATION WITH SAID SLUDGE HOLDING MEANS, SAID DEWATERING MEANS ADAPTED TO RAISE THE SOLIDS LEVEL OF SAID CONDITIONED SLUDGE TO AT LEAST 10 PPERCENT BY WEIGHT, AND MEANS TO CONTINUOUSLY FEED SAID DEWATERED SLUDGE TO THE REACTION ZONE OF SAID FLUIDIZED BED WHEREBY SAID SLUDGE IS INCINERATED.
Claim 16
Dependent Claim
20 words
An apparatus as described in claim 13, wherein said heat exchanger is located within the bed of said fluidized-bed reactor.
Claim 17
Dependent Claim
21 words
An apparatus as described in claim 13, wherein sludge is supplied to said heat exchange means by a positive displacement pump.
Claim 18
Dependent Claim
25 words
An apparatus, as described in claim 13, which includes means to supply water to said heat exchange means when the supply of sludge becomes inadequate.
Claim 19
Dependent Claim
33 words
An apparatus as described in claim 13, which includes pressure control means for said heat exchange means adapted to hold the pressure in said heat exchange means high enough to avoid flashing therein.
Claim 20
Dependent Claim
20 words
An apparatus as described in claim 17, wherein said pressure control means controls the pressure in said sludge holding means.
Claim 21
Dependent Claim
15 words
An apparatus as described in claim 13, wherein said dewatering means comprises a sedimentation chamber.
Claim 22
Dependent Claim
14 words
An apparatus as described in claim 13, wherein said dewatering means comprises a filter.
Claim 23
Dependent Claim
14 words
An apparatus, as described in claim 13, wherein said dewatering means comprises a centrifuge.
Claim 24
Dependent Claim
29 words
An apparatus, as described in claim 13, wherein said dewatering means raise the solids level of said conditioned sludge to from about 30 to about 70 percent by weight.
Claim 25
Dependent Claim
13 words
A method as described in claim 1 wherein said dewatered sludge is supra-autogeneous.
References Cited (Backward Citations)
US3319586A
Cited
US3589313A
Cited
US3733271A
Cited
US3815522A
Cited
US3779181A
Cited
US3805715A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |