Filter device with scavenger system

Claim 2

In a filter device which makes use of a housing divided into a dirty gas chamber and a clean gas chamber, an inlet communicating with the dirty gas chamber and an outlet connected by a passage with the clean gas chamber, a plurality of filter tubes extending into the dirty gas chamber and withdrawal means communicating with the outlet to cause flow of gas from the dirty gas chamber through the filter tubes into the clean gas chamber and through the passage to the outlet with the separation of solid particles on the ingoing side of the filter tubes as the gas filters therethrough, and means operable periodically to dislodge collected particles from the ingoing side of the filter tubes during a cleaning cycle, the improvement which comprises a scavenger hood, a passage communicating the scavenger hood with the clean gas chamber, a gas withdrawal means in communication with the scavenger hood, valve means mounted for movement between blocking and unblocking position with respect to the passage communicating the clean gas chamber with the scavenger hood and unblocking and blocking positions respectively with respect to the passage communicating the clean gas chamber with the outlet, in such manner that when the valve means is in blocking position with respect to the scavenger passage, it is in unblocking position with respect to the outlet passage to enable gas to pass from the clean gas plenum chamber to the outlet while blocking passage to the scavenger hood, and when the valve means is in unblocking position with respect to the scavenger passage, it is in blocking position with respect to the outlet passage to enable gas to pass from the clean gas plenum chamber to the scavenger hood while blocking passage to the outlet while gas continues to flow in one direction from the dirty gas chamber, through the filter tubes and into the clean gas chamber and then from the clean gas chamber to the scavenger hood or the passage connecting the clean gas chamber with the outlet, depending upon the position of the valve means.

Claim 3

A filter device as claimed in claim 1 in which the filter tubes extend vertically into the dirty gas chamber with the tubes closed at their bottom ends and open at their top ends with the open ends in communication with the clean gas chamber.

Claim 4

A filter device as claimed in claim 1 in which the means operable periodically to dislodge particles collected on the ingoing side of the filter tubes comprises means for introducing a pulse of high pressure gas into the open ends of the filter tubes.

Claim 5

A filter device as claimed in claim 3 which comprises a source of high pressure gas, nozzle means communicating with the source and extending into the clean gas chamber, and valve means for controlling the issuance of a short burst of high pressure gas from the nozzle.

Claim 6

A filter device as claimed in claim 1 which includes vertical walls in the housing for subdividing the housing into a number of modules common with the dirTy gas chamber, with each module having a separate passage communicating with the exhaust and a separate passage communicating with the scavenger hood.

Claim 7

In a filter device which makes use of a housing divided into a dirty gas chamber and a clean gas chamber, an inlet communicating with the dirty gas chamber and an outlet connected by a passage with the clean gas chamber, a plurality of filter tubes within the housing extending to within the dirty gas chamber and means to cause flow of gas from the dirty gas chamber through the filter tubes into the clean gas chamber with the separation of solid particles on the ingoing side of the filter tubes as the gas filters therethrough and means operative periodically to dislodge collected particles from the ingoing side of the filter tubes during a cleaning cycle, the improvement which comprises a scavenger hood, a passage communicating the scavenger hood with the clean gas chamber, a gas withdrawal means in communication with the scavenger hood, scavenger valve means mounted within said scavenger hood between the withdrawal means and the passage communicating the scavenger hood with the clean gas chamber for movement between open position to enable communication between said scavenger hood and the withdrawal means and closed position for blocking communication between said scavenger hood and withdrawal means, other valve means mounted for movement between blocking and unblocking position with respect to the passage communicating the clean gas chamber with the scavenger hood and with respect to the passage communicating the clean gas chamber with the outlet, such that at least during the initial portion of the filter cycle immediately following the cleaning cycle, said other valve means operates to block the passage communicating the clean gas chamber with the outlet and to unblock the passage between the clean gas chamber and the scavenger hood, and movement of the scavenger valve to open position, and after the cleaning cycle, said other valve means operates to unblock the passage communicating the clean gas chamber with the outlet and to block the passage between the clean gas chamber and the scavenger hood, and movement of the scavenger valve to closed position, which includes a return passage communicating withdrawal means with the dirty gas chamber for recycling the gas from the scavenger hood to the dirty gas chamber.

Claim 8

In a filter device which makes use of a housing divided into a dirty gas chamber and a clean gas chamber, an inlet communicating with the dirty gas chamber and an outlet connected by a passage with the clean gas chamber, a plurality of filter tubes within the housing extending to within the dirty gas chamber and means to cause flow of gas from the dirty gas chamber through the filter tubes into the clean gas chamber with the separation of solid particles on the ingoing side of the filter tubes as the gas filters therethrough and means operative periodically to dislodge collected particles from the ingoing side of the filter tubes during a cleaning cycle, the improvement which comprises a scavenger hood, a passage communicating the scavenger hood with the clean gas chamber, a gas withdrawal means in communication with the scavenger hood, scavenger valve means mounted within said scavenger hood between the withdrawal means and the passage communicating the scavenger hood with the clean gas chamber for movement between open position to enable communication between said scavenger hood and the withdrawal means and closed position for blocking communication between said scavenger hood and withdrawal means, other valve means mounted for movement between blocking and unblocking position with respect to the passage communicating the clean gas chamber with the scavenger hood and with respect to the passage communicating the clean gas chamber with the outlet, such that at least during the initial portion of the filter cycle immediately following the cleaning cycle, said other valve means operates to block the passage communicating the clean gas chamber with the outlet and to unblock the passage between the clean gas chamber and the scavenger hood, and movement of the scavenger valve to open position, and after the cleaning cycle, said other valve means operates to unblock the passage communicating the clean gas chamber with the outlet and to block the passage between the clean gas chamber and the scavenger hood, and movement of the scavenger valve to closed position, which includes a return passage communicating withdrawal means with the dirty gas chamber for recycling the gas from the scavenger hood to the dirty gas chamber.

Claim 9

In a filter device which makes use of a housing divided into a dirty gas chamber and a clean gas chamber, an inlet communicating with the dirty gas chamber and an outlet connected by a passage with the clean gas chamber, a plurality of filter tubes within the housing extending to within the dirty gas chamber and means to cause flow of gas from the dirty gas chamber through the filter tubes into the clean gas chamber with the separation of solid particles on the ingoing side of the filter tubes as the gas filters therethrough, and means operative periodically to dislodge collected particles from the ingoing side of the filter tubes during a cleaning cycle, the improvement which comprises a scavenger hood, a passage communicating the scavenger hood with the clean gas chamber, a gas withdrawal means in communication with the scavenger hood, scavenger valve means mounted within said scavenger hood between the withdrawal means and the passage communicating the scavenger hood with the clean gas chamber for movement between open position to enable communication between said scavenger hood and the withdrawal means and closed position for blocking communication between said scavenger hood and withdrawal means, other valve means mounted for movement between blocking and unblocking position with respect to the passage communicating the clean gas chamber with the scavenger hood and with respect to the passage communicating the clean gas chamber with the outlet, such that at least during the initial portion of the filter cycle immediately following the cleaning cycle, said other valve means operates to block the pasSage communicating the clean gas chamber with the outlet and to unblock the passage between the clean gas chamber and the scavenger hood, and movement of the scavenger valve to open position, and after the cleaning cycle, said other valve means operates to unblock the passage communicating the clean gas chamber with the outlet and to block the passage between the clean gas chamber and the scavenger hood, and movement of the scavenger valve to closed position, which includes that the passage communicating the clean gas chamber with the outlet and the passage communicating the clean gas chamber with the scavenger hood are arranged in spaced face to face relation and in which said other valve means comprises a single valve means mounted for movement between said passages to open one and close the other during the filtering operation and to close the one and open the other during the cleaning operation and for a short period of time thereafter.

Claim 10

In a filter device which makes use of a housing divided into a dirty gas chamber and a clean gas chamber, an inlet communicating with the dirty gas chamber and an outlet connected by a passage with the clean gas chamber, a plurality of filter tubes within the housing extending to within the dirty gas chamber and means to cause flow of gas from the dirty gas chamber through the filter tubes into the clean gas chamber with the separation of solid particles on the ingoing side of the filter tubes as the gas filters therethrough, and means operative periodically to dislodge collected particles from the ingoing side of the filter tubes during a cleaning cycle, the improvement which comprises a scavenger hood, a passage communicating the scavenger hood with the clean gas chamber, a gas withdrawal means in communication with the scavenger hood, scavenger valve means mounted within said scavenger hood between the withdrawal means and the passage communicating the scavenger hood with the clean gas chamber for movement between open position to enable communication between said scavenger hood and the withdrawal means and closed position for blocking communication between said scavenger hood and withdrawal means, other valve means mounted for movement between blocking and unblocking position with respect to the passage communicating the clean gas chamber with the scavenger hood and with respect to the passage communicating the clean gas chamber with the outlet, such that at least during the initial portion of the filter cycle immediately following the cleaning cycle, said other valve means operates to block the pasSage communicating the clean gas chamber with the outlet and to unblock the passage between the clean gas chamber and the scavenger hood, and movement of the scavenger valve to open position, and after the cleaning cycle, said other valve means operates to unblock the passage communicating the clean gas chamber with the outlet and to block the passage between the clean gas chamber and the scavenger hood, and movement of the scavenger valve to closed position, which includes that the passage communicating the clean gas chamber with the outlet and the passage communicating the clean gas chamber with the scavenger hood are arranged in spaced face to face relation and in which said other valve means comprises a single valve means mounted for movement between said passages to open one and close the other during the filtering operation and to close the one and open the other during the cleaning operation and for a short period of time thereafter.