Patent US4211340A successfully refreshed from Google Patents.
US4211340A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Catalyst regeneration
Assignee: Shell USA Inc
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Filing: 1978-08-21
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Granted: 1980-07-08
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Expires: 1998-08-21
Abstract
Abstract A system for controlling the addition of small amounts of material to process using the loss-in-weight method. The system uses digital control in combination with an on-off solenoid valve whose on time can be varied to meter the material uniformly at low rates.
Inventors
- 👤 Julius J. Szakasits
- 👤 Thomas C. Wadham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:25
CPC Classifications
G; G05; G05D; G05D7/00; G05D7/06; G05D7/0617; G05D7/0629; G05D7/0635
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
126 words
A system for controlling the addition of small amounts of material to a process comprising: a container for said material, said container being connected to said process to supply the material thereto; weighing means disposed to weigh said container and material; a valve means disposed in the connection between said container and said process to control the flow of material to said process; and, a control system, said control system being coupled to said weighing means and said valve means to intermittently open and close the valve means at a preselected modulation frequency to provide a controlled flow of said material to said process and further suspending operation of the valve means in response to sensing a predetermined change in weight of said container and material.
Claim 2
Independent Claim
126 words
A system for controlling the addition of small amounts of material to a process comprising: a container for said material, said container being connected to said process to supply the material thereto; weighing means disposed to weigh said container and material; a valve means disposed in the connection between said container and said process to control the flow of material to said process; and, a control system, said control system being coupled to said weighing means and said valve means to intermittently open and close the valve means at a preselected modulation frequency to provide a controlled flow of said material to said process and further suspending operation of the valve means in response to sensing a predetermined change in weight of said container and material.
Claim 3
Dependent Claim
25 words
The system of claim 1 wherein said valve means is a solenoid valve pulsed in an on-off mode to control the flow of said material.
Claim 4
Dependent Claim
29 words
The system of claim 2 and in addition said control system including means for varying the on cycle of said solenoid valve while maintaining the same preselected modulation frequency.
Claim 5
Dependent Claim
27 words
The system of claim 3 and in addition said control system including means for varying the quantity of material added to said process per unit of time.
Claim 6
Dependent Claim
73 words
The system of claim 4 wherein said control system comprises, a clock, a first controllable frequency synthesizer coupled to said clock for producing a first frequency; a second controllable frequency synthesizer coupled to said clock for producing said preselected modulation frequency, said first frequency being used to control the operation and suspension of operation of said solenoid valve and said modulation frequency being used to control the frequency of operation of said solenoid.
Claim 7
Dependent Claim
50 words
The system of claim 5 and in addition a comparing circuit, both said first controllable frequency synthesizer and said weighing means being coupled to said comparing circuit; said comparing circuit being coupled to a valve control circuit disposed to control the operation and suspension of operation of said solenoid valve.
Claim 8
Dependent Claim
18 words
The system of claim 1 wherin said material is a gas contained in a storage vessel under pressure.
Claim 9
Dependent Claim
27 words
The system of claim 7 wherein said storage vessel is suspended at one end from a fixed beam and at the other end by a load cell.
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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) | 1983-07-08 | 1984-01-07 | 1984-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-07-08 | 1988-01-07 | 1988-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-07-08 | 1992-01-07 | 1992-07-08 | $7700.00 | Window Closed / Lapsed |