US 4,306,888 AGranted

Method for filtering dust

AssigneePhillips Petroleum Company

InventorPaul J. Cheng

Life of this patent

Estimating the term…

Abstract

A method for filtering dust from a dust-laden gas stream utilizing a tubular fabric filter is provided wherein cleaning of said filter is accomplished by backflow of gas through the filter wall and axial pulsations of gas along the longitudinal axis of the tubular filter.

Claims6

Dependent claims

A method for filtering dust from a stream of dust-laden gas, which comprises:

(a) flowing a first stream of dust-laden gas into an interior volume of a first tubular fabric filter positioned in a first chamber and a second tubular fabric filter positioned in a second chamber, each of said first and second tubular fabric filters having a filter wall with an interior upstream surface and an exterior downstream surface, supported at longitudinally spaced apart positions against inward collapse by supportive rings adjacent the filter wall and tensioned along its longitudinal axis to a tension of between about 1 and 10 pounds per inch of circumference at the open end of the filter;
(b) collecting adjacent the interior upstream surface of each filter wall at least a portion of the dust from the dust-laden first stream of gas and allowing at least a portion of the gas to pass through each filter wall;
(c) intervallically repressuring at least a portion of the gas which passes through the filter wall of the first filter and flowing said gas from the exterior downstream surface of the second tubular fabric filter to the interior upstream surface of the second tubular fabric filter, the repressurized gas being at insufficient pressure to collapse the second tubular fabric filter;
(d) intervallically repressurizing at least a portion of the gas which passes through the filter wall of the second filter and flowing said gas from the exterior downstream surface of the first tubular fabric filter to the interior upstream surface of the first tubular fabric filter, the repressurized gas being at insufficient pressure to collapse the first tubular fabric filter;
(e) continuing steps (a), (b), and (c) for a number of times and then, while performing step (c),
(f) introducing a pulse of gas axially and downwardly into the second tubular fabric filter;
(g) continuing steps (a), (b), and (d) for a number of times and then, while performing step (d),
(h) introducing a pulse of gas axially and downwardly into the first tubular fabric filter.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/114,927Filed 24 Jan 1980
Granted: 22 Dec 1981
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

B01D 46/2411
Characterised by the physical shape or structure of the filtering element: filter cartridges
B01D 46/58
With multiple filtering elements, characterised by their mutual disposition: connected in parallel
B01D 46/71
By acting counter-currently on the filtering surface, e.g. by flushing on the non-cake side of the filter: with pressurised gas, e.g. pulsed air
B01D 2265/028
Non-permanent measures for connecting different parts of the filter: snap, latch or clip connecting means

Family

No related US applications are recorded in the indexed filing history.

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Abstract

A method for filtering dust from a stream of dust-laden gas, which comprises:

(a) flowing a first stream of dust-laden gas into an interior volume of a first tubular fabric filter positioned in a first chamber and a second tubular fabric filter positioned in a second chamber, each of said first and second tubular fabric filters having a filter wall with an interior upstream surface and an exterior downstream surface, supported at longitudinally spaced apart positions against inward collapse by supportive rings adjacent the filter wall and tensioned along its longitudinal axis to a tension of between about 1 and 10 pounds per inch of circumference at the open end of the filter;
(b) collecting adjacent the interior upstream surface of each filter wall at least a portion of the dust from the dust-laden first stream of gas and allowing at least a portion of the gas to pass through each filter wall;
(c) intervallically repressuring at least a portion of the gas which passes through the filter wall of the first filter and flowing said gas from the exterior downstream surface of the second tubular fabric filter to the interior upstream surface of the second tubular fabric filter, the repressurized gas being at insufficient pressure to collapse the second tubular fabric filter;
(d) intervallically repressurizing at least a portion of the gas which passes through the filter wall of the second filter and flowing said gas from the exterior downstream surface of the first tubular fabric filter to the interior upstream surface of the first tubular fabric filter, the repressurized gas being at insufficient pressure to collapse the first tubular fabric filter;
(e) continuing steps (a), (b), and (c) for a number of times and then, while performing step (c),
(f) introducing a pulse of gas axially and downwardly into the second tubular fabric filter;
(g) continuing steps (a), (b), and (d) for a number of times and then, while performing step (d),
(h) introducing a pulse of gas axially and downwardly into the first tubular fabric filter.

5 more elements

Facts

Application

06/114,927Filed 24 Jan 1980

Granted

22 Dec 1981

Term ends

Not estimatedThe source records don’t support an estimate.

Classification6 codes

B01D 46/2411
Characterised by the physical shape or structure of the filtering element: filter cartridges
B01D 46/58
With multiple filtering elements, characterised by their mutual disposition: connected in parallel
B01D 46/71
By acting counter-currently on the filtering surface, e.g. by flushing on the non-cake side of the filter: with pressurised gas, e.g. pulsed air
B01D 2265/028
Non-permanent measures for connecting different parts of the filter: snap, latch or clip connecting means