Gas separation – With nonliquid cleaning means for separating media – Solid agent cleaning member movingly contacts apparatus
Patent
1995-12-18
1997-12-09
Bushey, C. Scott
Gas separation
With nonliquid cleaning means for separating media
Solid agent cleaning member movingly contacts apparatus
55283, 55338, 55414, 55417, 95 20, 95 26, B01D 35147
Patent
active
056955340
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention concerns air filtration installations of the type including a device for recycling the filtered air.
2. Discussion of the Background Information
Recycling air inside buildings allows savings to be made because of the recovery of heat carried by the filtered air.
This type of recycling imposes a filtration quality governed by standards which, at the present time, requires a maximum limit of 0.6 mg of dust per m3 of recycled air.
This standard changes over time. For example, the upper limit soon to be reduced by a factor of three.
All filtration systems of the type described in documents DE-A-2704377 and 2831167, U.S. Pat. No. 3,383,840 can be used with recycling of the filtered air, as can the one described in document EP-A-0 343 061 filed by the Applicant.
However, the drawback of all these installations is that they cause a large amount of dust to be released during the filter sleeve cleaning operations.
It is known, through document FR-A-2 666 246 filed by the Applicant, that the dust ratio in the recycled air during filter unclogging operations can be reduced. This reduction in the dust ratio is obtained by exhausting the filtered air towards the outside atmosphere whenever this filtered air is abnormally and temporarily laden with dust.
The last of the above mentioned documents proposes a bypass device made up of a shutter housed in the air circulation shafts specifically, the shutter that is articulated about an axis located at the level of the head of a kind of T formed by the filtered air inlet shaft and two other shafts. One of the shafts recycles the filtered air and the other shaft exhausts the air towards the outside atmosphere.
SUMMARY OF THE INVENTION
This invention proposes an installation that makes it possible to better control the air exhausting phase to the atmosphere during the filter medium cleaning operation. It provides highly reliable operation that eliminates any risk of dust being accidentally exhausted into the recycled air.
This invention also proposes an installation designed to better control the air flows for recycling or exhausting to the atmosphere.
According to the invention, the installation may include a control device to control a bypass device including an adjustable time delay device used to establish a bypass cycle, and in particular: seconds, for example, and corresponding to a length of time separating an unclogging order and an unclogging operation and during which the bypass device is implemented in order to channel the filtered air towards the atmosphere; 6 to 10 seconds, for example, and which corresponds to a length of time at the end of which the bypass device is again implemented in order to recycle the filtered air.
According to another embodiment of the invention, a device for controlling a bypass device may include a time delay for establishing a time interval of length t3 corresponding to a minimum length of time between an unclogging operation and a starting up of a new bypass cycle.
According to a further embodiment of the invention, a control device is operated by a pressure-operated switch designed to monitor the caking up of the filters. Alternatively, the control device may be operated by a timer which can be adjusted according to a type of dust to be processed.
According to yet a further embodiment of the invention, a device for controlling a bypass device can also be brought into operation when the installation is started up, for example, for unclogging A bypass cycle, i.e. an opening of the bypass device to exhaust air to the outside atmosphere, may be included for controlling the bypass device. The device may also include a time delay establishing a length of time corresponding to t1+t2 for implementing recycling.
The invention also concerns an installation and in particular an installation in which the bypass device includes two shutters. One shutter controls recycling and the other shutter controls exhausting to the atmosphere, and a device for controlling the shutters.
T
REFERENCES:
patent: 2964129 (1960-12-01), Labbe
patent: 3383840 (1968-05-01), Johnson et al.
patent: 4461633 (1984-07-01), Bodovsky
patent: 5032153 (1991-07-01), Cattin
patent: 5120333 (1992-06-01), Davis
patent: 5405421 (1995-04-01), Swisher, Jr.
Bushey C. Scott
Societe Cattinair
LandOfFree
Air filtration installation with recycling of filtered air does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Air filtration installation with recycling of filtered air, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Air filtration installation with recycling of filtered air will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1604000