US3781518A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vacuum pumps
Assignee: BOC Group Ltd
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Filing: 1972-06-29
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Granted: 1973-12-25
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Expires: 1992-06-29
Abstract
Abstract An electrically heated vaporiser particularly for a vapour vacuum pump, comprising a porous electrical heating element through which the liquid to be vaporised is pumped and having means for retaining the mechanical integrity of the heating element despite thermal movements and for reducing heat losses.
Inventors
- 👤 B Power
- 👤 R Oswald
- 👤 D Tooth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:51
CPC Classifications
F; F22; F22B; F22B1/00; F22B1/28
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
156 words
An electrically heated vaporizer comprising an elongated support tube through which the liquid to be vaporized passes, a casing enclosing the lower portion of said tube, a tubular, porous electrical heating element within said casing and encircling said support tube at the lower portion thereof, means placing said electrical heating element under axial compression, at least one layer of porous insulating material in intimate contact with the inner surface of said heating element and radially spaced from said tube at the lower end thereof, a first collar member welded to said tube portion that extends outside said casing, a second collar in sliding, fluid tight engagement with a portion of said tube that extends outside said casing and below and adjacent said first collar, means connecting said electrical heating element to said second collar, and spring means betwEen said first collar and said second collar to retain said heating element under axial compression during thermal movements.
Claim 2
Dependent Claim
156 words
An electrically heated vaporizer comprising an elongated support tube through which the liquid to be vaporized passes, a casing enclosing the lower portion of said tube, a tubular, porous electrical heating element within said casing and encircling said support tube at the lower portion thereof, means placing said electrical heating element under axial compression, at least one layer of porous insulating material in intimate contact with the inner surface of said heating element and radially spaced from said tube at the lower end thereof, a first collar member welded to said tube portion that extends outside said casing, a second collar in sliding, fluid tight engagement with a portion of said tube that extends outside said casing and below and adjacent said first collar, means connecting said electrical heating element to said second collar, and spring means betwEen said first collar and said second collar to retain said heating element under axial compression during thermal movements.
Claim 3
Dependent Claim
26 words
An electrically heated vaporiser as claimed in claim 1 wherein said porous electrical insulation material is made of a ceramic fibre in the form of paper.
Claim 4
Dependent Claim
95 words
The vaporizer set forth in claim 1 in which said support tube comprises an inlet tube for the liquid to be vaporized, said tube having passages formed in the walls thereof for the passage of liquid therethrough, means forming a chamber encircling said tube and having a portion extending within said casing, said portion within said casing disposed within said heating element, whereby said chamber is in communication with the inner surface of said heating element to thereby cool the inner and outer surfaces of said tube as liquid is passed to said heating element.
Claim 5
Dependent Claim
69 words
The vaporizer of claim 1 and further including a metal cap secured to said tubular, porous heating element at each end thereof in electroconductive contact therewith, means for sealing the joints between the respective ends of said tubular, porous heating element and the caps secured thereto, said sealing means comprising an annular gasket of flexible electrically conductive material between each cap and the respective ends of said tubular element.
Claim 6
Dependent Claim
134 words
The vaporizer of claim 1 and further including a flange outside said casing and exposed to ambient temperature to be thereby maintained relatively cool, means interconnecting said flange to said tubular, porous electrical heating element, said interconnecting means comprising a first tubular member of low thermal conductivity connected at one end to said flange and at the other end to said heating element, and a second tubular member of low thermal conductivity connected at one end to said flange and closely spaced from said first tubular member at the flange connected end and forms a supporting means at the other end for a nozzle through which vaporized liquid is passed, said close spacing between the respective ends of the first and second tubular members inhibiting the passage of vapor to the relatively cool flange.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |