US3672067A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for steam drying filter cake
Assignee: Envirotech Corp
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Filing: 1970-10-30
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Granted: 1972-06-27
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Expires: 1990-10-30
Abstract
Abstract A method is disclosed for steam drying filter cake on a drum or disc type vacuum filter having a steam drying cycle wherein optimum cake thickness and moisture content is obtained at optimum thermal efficiency by controlling steam condensation within the cake at constant steam input, through control of the vacuum on the filter during cake formation and during filter cake drying with generally constant speed of rotation of the filter element.
Inventors
- 👤 Robert C Emmett Jr
- 👤 Donald A Dahlstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:24
CPC Classifications
B; B01; B01D; B01D35/00; B01D35/14; B01D35/143; B01D33/00; B01D33/15; B01D33/21; B01D33/23; B01D33/58; B01D33/62; B01D33/66; B01D33/663; B01D33/80; B01D33/801; B01D33/804; B01D33/809; B01D2201/00; B01D2201/28; B01D2201/282
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
95 words
A method for drying a filter cake formed by continuous filtration of a feed slurry on a closed hood type rotary vacuum filter comprising: a. passing steam at a constant input rate through the filter cake in a zone above the surface of the feed slurry; b. controlling condensation of the steam within the filter cake by applying a vacuum to the under surface of the filter cake in said zone; c. continuously monitoring and controlling the applied vacuum to the filter cake in said zone to maintain optimum thermal efficiency of the apPlied steam.
Claim 2
Independent Claim
95 words
A method for drying a filter cake formed by continuous filtration of a feed slurry on a closed hood type rotary vacuum filter comprising: a. passing steam at a constant input rate through the filter cake in a zone above the surface of the feed slurry; b. controlling condensation of the steam within the filter cake by applying a vacuum to the under surface of the filter cake in said zone; c. continuously monitoring and controlling the applied vacuum to the filter cake in said zone to maintain optimum thermal efficiency of the apPlied steam.
Claim 3
Independent Claim
130 words
A method for drying a filter cake formed by continuous filtration of a feed slurry on a closed hood type rotary vacuum filter comprising: a. continuously monitoring and controlling the vacuum applied to the filter element in a zone below the surface of the feed slurry to maintain an optimized cake thickness in a zone above the surface of the feed slurry; b. further controlling the filtration rate by continuously monitoring and controlling the vacuum applied to the filter cake in a zone above the surface of the slurry; c. directing live steam in the zone above the feed slurry at a rate such that substantially all of the steam is condensed in passing through the filter cake to maintain the condensation front in the zone of the filter medium.
Claim 4
Independent Claim
130 words
A method for drying a filter cake formed by continuous filtration of a feed slurry on a closed hood type rotary vacuum filter comprising: a. continuously monitoring and controlling the vacuum applied to the filter element in a zone below the surface of the feed slurry to maintain an optimized cake thickness in a zone above the surface of the feed slurry; b. further controlling the filtration rate by continuously monitoring and controlling the vacuum applied to the filter cake in a zone above the surface of the slurry; c. directing live steam in the zone above the feed slurry at a rate such that substantially all of the steam is condensed in passing through the filter cake to maintain the condensation front in the zone of the filter medium.
Claim 5
Dependent Claim
45 words
The method defined in claim 2 wherein the steam passed to the filter cake is at a temperature of about 225* to 250* fahrenheit and the steam is passed at an amount of 50 to 100 Kg. of steam per metric ton of filter cake.
Claim 6
Dependent Claim
20 words
The invention defined in claim 3 wherein the dry filter cake is from about one-fourth to 2 inches in thickness.
Claim 7
Dependent Claim
42 words
The invention defined in claim 4 wherein the formed cake is about one-fourth to about one-half inch in thickness when the particles in the slurry to be filtered are in the range of 30 to 40 percent or more at -200 mesh.
References Cited (Backward Citations)
US3186103A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |