Patent US3275404A successfully refreshed from Google Patents.
Patent US3859842A successfully refreshed from Google Patents.
US3859842A
Expired / Lapsed
US
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System for determining the dust content of gases
Assignee: Frieseke and Hoepfner GmbH
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Filing: 1973-08-01
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Granted: 1975-01-14
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Expires: 1993-08-01
Abstract
Abstract A system for measuring the dust content of gases traversing a stack or other duct, e.g., a chimney stack, before release of the gases into the atmosphere, comprises a conduit arrangement with pumps establishing a circulation of air from and to the atmosphere which is unbalanced between the intake and discharge branches to permit induction of the sampled stream of gas from the stack between these branches and upstream of a dust detector. A device for generating an output representing a pressure differential receives one input representing the static pressure of the stack and another input representing the total flow pressure (static pressure + dynamic pressure) therein controls a throttle which, in turn, is followed by an adjustable flowcontrol means for producing the imbalance in accordance with the dynamic pressure of the gases in the stack.
Inventors
- 👤 Julius Bosch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:42
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/06; G01N15/0606; G01N15/0618; G01N1/00; G01N1/02; G01N1/22; G01N1/2247; G01N2001/225
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
266 words
A system for measuring the dust content of a gas stream traversing a duct, said system comprising: a pair of motor-driven pumps, each having an inlet and an outlet, the inlet of one of said pumps and the outlet of the other pump forming respEctive branches communicating with the atmosphere; a dust detector having an input side connected to the outlet of said one of said pumps and an output side connected to the inlet of said other pump; a sampling tube open into said duct and communicating with said input side of said dust detector downstream of said one of said pumps; a first hrottle located at said inlet branch downstream of its communication with the atmosphere and a second throttle located at said outlet branch upstream of its communication with the atmosphere; means for varying the effective flow cross section of one of said throttles; operating means responsive to the flow velocity of said gas stream in said duct and operatively connected to said means for varying said cross section for adjusting said cross section of said one of said throttles to generate a flow-rate differential between said inlet branch and said outlet branch in dependence upon said flow velocity; and an automatic differential controller including: an adjustable-cross section further throttle in one of said branches, a control member shiftable in response to a pressure differential across said branches, and means operatively connecting said control member to said first throttle for increasing the flow-rate differential across said branches in conjunction with said operating means upon an increase in said flow velocity and vice versa.
Claim 2
Independent Claim
266 words
A system for measuring the dust content of a gas stream traversing a duct, said system comprising: a pair of motor-driven pumps, each having an inlet and an outlet, the inlet of one of said pumps and the outlet of the other pump forming respEctive branches communicating with the atmosphere; a dust detector having an input side connected to the outlet of said one of said pumps and an output side connected to the inlet of said other pump; a sampling tube open into said duct and communicating with said input side of said dust detector downstream of said one of said pumps; a first hrottle located at said inlet branch downstream of its communication with the atmosphere and a second throttle located at said outlet branch upstream of its communication with the atmosphere; means for varying the effective flow cross section of one of said throttles; operating means responsive to the flow velocity of said gas stream in said duct and operatively connected to said means for varying said cross section for adjusting said cross section of said one of said throttles to generate a flow-rate differential between said inlet branch and said outlet branch in dependence upon said flow velocity; and an automatic differential controller including: an adjustable-cross section further throttle in one of said branches, a control member shiftable in response to a pressure differential across said branches, and means operatively connecting said control member to said first throttle for increasing the flow-rate differential across said branches in conjunction with said operating means upon an increase in said flow velocity and vice versa.
Claim 3
Dependent Claim
68 words
The system defined in claim 1 wherein said operating means includes: a pressure-sensing capsule responsive to pressures applied to opposite sides thereof for producing an output representing the differential of the latter pressures; means for applying the static pressure in said duct to one side of said pressure-sensing capsule; and means for applying the total velocity pressure in said duct to the other side of said pressure-sensing capsule.
Claim 4
Dependent Claim
34 words
The system defined in claim 2 wherein said automatic differential controller further comprises respective pneumatic bellows having tubes bridged on opposite sides of said first and second throttles in said inlet and outlet branches.
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) | 1978-01-13 | 1978-07-15 | 1979-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-13 | 1982-07-15 | 1983-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-13 | 1986-07-15 | 1987-01-14 | $7700.00 | Window Closed / Lapsed |