US4218016A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lance tube construction
Assignee: Diamond Power International Inc
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Filing: 1978-07-26
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Granted: 1980-08-19
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Expires: 1998-07-26
Abstract
Abstract A lance tube for use in long retracting cleaning devices of the soot blower type which in operation discharge jets of liquid against the fouled surfaces of heat exchangers such as the slag-coated surfaces of boiler tubes and the like incorporates a light weight hollow filler tube mounted in the lance tube by a helical spacer rib.
Inventors
- 👤 Melvin A. Freund
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:39
CPC Classifications
F; F28; F28G; F28G3/00; F28G3/16; Y; Y10; Y10S; Y10S239/00; Y10S239/13
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
131 words
A lance tube for cleaning apparatus for boilers and the like, which apparatus is designed to project an aqueous liquid, comprising an elongated tube having an inlet end and a discharge end, discharge orifice means appurtenant to the discharge end thereof and through which tube liquid is adapted to be conducted for discharge through such orifice means, characterized by a filler tube extending longitudinally within the lance tube and comprising a sealed hollow enclosure, the filler tube being of lesser diameter than the lance tube and having a total weight less than the weight of water displaceable thereby, means being provided to space the filler tube from the internal wall of the lance tube, whereby liquid may flow between the lance tube and filler tube for discharge through such orifice means.
Claim 2
Dependent Claim
131 words
A lance tube for cleaning apparatus for boilers and the like, which apparatus is designed to project an aqueous liquid, comprising an elongated tube having an inlet end and a discharge end, discharge orifice means appurtenant to the discharge end thereof and through which tube liquid is adapted to be conducted for discharge through such orifice means, characterized by a filler tube extending longitudinally within the lance tube and comprising a sealed hollow enclosure, the filler tube being of lesser diameter than the lance tube and having a total weight less than the weight of water displaceable thereby, means being provided to space the filler tube from the internal wall of the lance tube, whereby liquid may flow between the lance tube and filler tube for discharge through such orifice means.
Claim 3
Dependent Claim
24 words
A lance tube as defined in claim 1 wherein the filler tube extends a substantial proportion of the full length of the lance tube.
Claim 4
Dependent Claim
53 words
A lance tube as defined in claim 1, including helically disposed spacing means carried by the filler tube and substantially bridging the radial distance between the filler tube and the internal wall of the lance tube, whereby liquid moving longitudinally between the tubes is conducted in a helical path by such spacing means.
Claim 5
Dependent Claim
35 words
A lance tube as defined in claim 1, including means attaching the filler tube at one end thereof only to the lance tube, whereby differential expansion is permitted between the filler tube and lance tube.
Claim 6
Dependent Claim
18 words
A lance tube as defined in claim 1 wherein the filler tube is formed of light weight material.
Claim 7
Dependent Claim
28 words
A lance tube as defined in claim 1 wherein the filler tube is formed of material of relatively thin gauge, the interior of the filler tube being pressurized.
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) | 1983-08-19 | 1984-02-18 | 1984-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-19 | 1988-02-18 | 1988-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-19 | 1992-02-18 | 1992-08-19 | $7700.00 | Window Closed / Lapsed |