CA1069835A - Dust collector - Google Patents
Dust collectorInfo
- Publication number
- CA1069835A CA1069835A CA230,345A CA230345A CA1069835A CA 1069835 A CA1069835 A CA 1069835A CA 230345 A CA230345 A CA 230345A CA 1069835 A CA1069835 A CA 1069835A
- Authority
- CA
- Canada
- Prior art keywords
- filter
- air
- elements
- chamber
- filter elements
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/52—Particle separators, e.g. dust precipitators, using filters embodying folded corrugated or wound sheet material
- B01D46/521—Particle separators, e.g. dust precipitators, using filters embodying folded corrugated or wound sheet material using folded, pleated material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/24—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies
- B01D46/2403—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies characterised by the physical shape or structure of the filtering element
- B01D46/2411—Filter cartridges
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/42—Auxiliary equipment or operation thereof
- B01D46/4281—Venturi's or systems showing a venturi effect
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/66—Regeneration of the filtering material or filter elements inside the filter
- B01D46/70—Regeneration of the filtering material or filter elements inside the filter by acting counter-currently on the filtering surface, e.g. by flushing on the non-cake side of the filter
- B01D46/71—Regeneration of the filtering material or filter elements inside the filter 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D50/00—Combinations of methods or devices for separating particles from gases or vapours
- B01D50/20—Combinations of devices covered by groups B01D45/00 and B01D46/00
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2201/00—Details relating to filtering apparatus
- B01D2201/31—Other construction details
- B01D2201/313—Means for protecting the filter from the incoming fluid, e.g. shields
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2265/00—Casings, housings or mounting for filters specially adapted for separating dispersed particles from gases or vapours
- B01D2265/02—Non-permanent measures for connecting different parts of the filter
- B01D2265/024—Mounting aids
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Physics & Mathematics (AREA)
- Geometry (AREA)
- Filtering Of Dispersed Particles In Gases (AREA)
- Filtering Materials (AREA)
Abstract
Abstract An air filter for removing particulate matter from air with continuous cleaning of the filter element:
the size of the filter is greatly reduced compared to conventional bag type filters by the use of pleated paper filter elements constructed to withstand the sudden pulsating forces inherent in reverse flow cleaning, and operated at derated velocities. Also included is a novel arrangement for mounting the filter elements in a manner which facili-tates their removal and replacement without tools or accessories.
the size of the filter is greatly reduced compared to conventional bag type filters by the use of pleated paper filter elements constructed to withstand the sudden pulsating forces inherent in reverse flow cleaning, and operated at derated velocities. Also included is a novel arrangement for mounting the filter elements in a manner which facili-tates their removal and replacement without tools or accessories.
Description
3~3~j Background~of the In~ention The current interest in avoidance of air polution hasin a sense only emphasized an ongoing trend to prevent massi~e discharge of particulate matter, often of commercial value, into the ambient atmosphere. Air filters of many types are known, more or less specially adapted for widely varying uses.
There are numerous situations where a large volume of air must be treated on a continuous-basis. In order to handle several thousand cubic feet per minute a large filter area must be available, and even then a very considerable pressure drop takes place across the filter. From a practical viewpoint it is necessar~ that some form of continued cleaning of the filter medium be pro~ided, as duplication of equipment to permit shutdown for cleaning is prohibitively expensive both in cost and in space, while the period of operation of a ~ilter unit before its efficiency is reduced to an intolerable~ level by the matter accumulated thereon is not long.
A standard way of constructing air filters has been to provide a housing divided into inlet and clean air chambers by a partition having a plurality of apertures. A sock or bag of suitable fabric, often on a wire frame, is suspended in each aperture, and a suitable pump or blower causes air flow through the bags, so that the undesired particulate matter collects on the outer surfaces of the bags. Cleaning is accomplished by directing brief jets of air into the bags , a few at a time, in a predetermined sequence, thus reversing the flow through the bays and subjecting them ko a minor physical shaking. This removes the deposited material, most .. . .
. . . .
of which falls to the bottom o~ the inlet chambex for removal either intermittently or continuously with a rotary air lock, In a typical example, a filter of this sort to handle approximately 8000 cuhic feet of air perminute with a flow velocity of 8-lO cubic feet per minute per s~uare foot of area of medium,requires 770 square feet of bag surface, a total of 81 bags 4-1~2 inches in diameter and 8 feet long.
Thus even apart from the continuous cleaning component.s, the filter elements ~alone-70ccupy a housing of very considerable size.
It also became obvious very quickly that the filter bags, and their supporting frames, are bulky and awkward to ;~
deal with, difficult to install and replace, and subject to rapid wear.
Efforts have been made to find substitutes for filter bags, and some of these alternatives have been successful to a limited exten-~ in laboratory situations. Thus porus metal and ceramic media turned out to have too low a capacity, and woven metal media are prohibitively expensive. Pleated filters ; 20 made of paper ~ave some promise, but had too short a lifetime to be practical.
Summary of the Invention The present invention greatly reduces the dimensions of air filters and increases their convenience and efficiency by the use of pleated paper filter elements having special structure to extend their service life, by operating the filter elements at a derated flow velocity~ and hy providing improved means for mounting khe elements in readily replaceable ~` fashion. The elements in question were developed for the ` 30 .
' ' ' , entirel~ different field of protecking the engines of motor vehicles such as trucks and o~f-the-road vehicles ~rom road dust and other particulate matter, and accordin~ly are of suitably rugged construction for that purpose~ In their intended use, however, they were not subject to the rigors of reverse jet cleaning.
It is the discovery of this invention that these pleated paper ~ilters, when subjected to a reduced flow velocity of 1-3 cubic feet per minute per square foot of filter area, are comparable to cloth bags in volume oE air handled, that they can withstand the stresses of continuous cleaning by -reverse jets, and that they markedly reduce the total size of a filter unit, often by a factor of two. Sixteen of such elements present 3060 feet of filtering surface, in a height of 28 inches rather than 8 feet, and replace the 81 bags mentioned above. The pleated paper filters are also less expensive than the cloth bags.
It is accordingly a principal object of the invention to provide a new and improved air filter capable of handling large volumes of air while occupying a smaller space than previous filters. Another object is to provide such a filter capable of using pleated paper filter elements of improved construction. A more specific object of the invention is to provide such a filter including novel means for mounting said elements in readily replaceable ~ashion.
Accordingly, the present invention comprises, in a pulse jet cleaned air filter, the improvement which comprises a derated pleated papex filte~ element. The meaning of the term "derated" can be better understood with the a5sistance of the following explanation: In any filter design problem, the .
~LOt~9l~5 volume of air -to be filtered is a known ~uantity, and the effective porosity of the filter medium in operation on con-taminated gas is determined, somewhat pragmatically, by the nature, fineness, and concentration of the contaminant, the temperature of the air passing through the filter and any characteristics peculiar to the specific application. The porosity being known, it becomes possible to determine the area of medium required to pass the necessary volume of air. The quotient of air volume in cubic feet per minute divided by the filter area in square feet is the filter "rating" in feet per minute. The rating not only has the climensions of velocity, but is in fact a measure of the speed of air passing through the filter.
"Deratiny" a filter is simply operating it at less than its normal capacity. Practically, this means using more filter area than normal, since the total air volume cannot be reduced.
A numerical example may be instructive. Suppose it is necessary to filter 900 cubic feet of air per minute through a medium of such porosity that 100 square feet of filter area is necessary:
the filter rating and the speed of air through the filter are 9 fpm. If now the filter area is increased to 300 square feet, the functional filter rating is now 3 fpm, so that the filter - has been derated by a factor of 3, and the speed of air through the filter is reduced to 1/3 its former value. This has the further advantage of increasing the filter efficiency, since at the lower air velocity contaminant particles are less likely to be ~arried through the filter medium, and are more easily removed in cleaning.
The present invention is directed to a filter to be used in an application requiring a known volumetric filtering rate. The filter comprises, in part, a housing divided into - , - 3a -' 10~ 5 first and secon~ chambers by a parti~ion having a plurality of apertures. The filter contains a number of hollow cylindrical filter elements of pleated, porous, non-woven shee~ material (e.g. paper) of known rating-filtering capacity per unit area.
The folds between the pleats of each cylinder are arranged parallel to the axis of the cylinder. A ring and a disc of imperforate material are secured to the shells and the pleats, the ring at one end of the cylinder and the disc at the other end of the cylinder. The foregoing assists to prevent any significant movement of the material in the element and thereby maintains the rigidity and effective filtering area of the elements. The filter also includes means to removably mount a filter element in each aperture of the partition. The number of filter elements should be such as to give the filter a total capacity greater than the known volumetric rate by a factor of about four. Means are also provided to admit a fluid laden with particulate material to the first chamber.
In addition, means are provided to exhaust fluid from the second chamber whereby fluid normally flows radially through the elements and matter collects on their surfaces. Aligned with each aperture are means for providing brief pulses of fluid to the elements in a predetermined sequence in a direction opposite to the normal fluid flow. This causes the matter collected on the surfaces of the elements to be released.
The pulse generating means of the above described filter may be located in the second chamber and the filter elements in the first chamber so that the normal fluid flow through the cylinders is radially inward. Further, access means may be pravided to the interior of the housiny to enable removal and replacement of the filter e].ements. ~n addition, ~ - 3b -.
the ~irst chamber may include a hopper, a deflector, and a discharge valve serving -to receive, separate and remove particulate matter present in the fluid sought to be filtered.
It will be appreciated that the above described invention may be adapted to perform as an air cleaning apparatus. Reverse jet cleaning means are provided in the housing to periodically remove the matter collected on the filter element surfaces. This is achieved by directing brief pulses of high pressure air into the elements at pre-determined intervals in the opposite direction from thenormal air flow.
Means in the air cleanin~ apparatus are also provided for reducing the impact of ~he particulate matter on the pleated paper filter medium. This is accomplished by grossly derating the filter elements so that the particulate matter can be periodically removed during reverse jet cleaning and so that the pleated paper filter medium can withstand the stresses placed upon it by continuous reverse jet cleaning. The required means may be effected by having the plurality of filter elements possess a total filter area sufficient to reduce the velocity of air flow through each filter element to a velocity substantially lower than the normal rated velocity.
The foregoing air cleaning apparatus may be further adapted to comprise a dust collector apparatus. The reverse jet cleaning means would also include a nozzle aligned with each aperture to effect the high pressure intermittent pulse cleaning of dust from the filter element surfaces. The velocity of air flowing khrough each filter element may be between about one to three cubic feet per minute per square foot of filter area.
3c -' . - ' . .
;983~i various other objec-ts, advantages, and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part - 3d -: '` `
- ~0~ 5 hereof. However, for a better understanding of the invention, its advantages, and objects attained by its use, reference should be had to the drawing which forms a further part hereof, and to the accompanying descriptive matter, in which khere is illus-trated and described a preferred embodiment of the invention.
srief ~escription of the Drawings In the drawing Figure 1 is a front elevational view of an air filter embodying the invention, parts being broken away for clarity;
Figure 2 is a similiar side elevation;
Figure 3 is a similiar plan view;
Figure 4 is a fragmentary sectional view taken a].ong the axis of a filter element; and Figure 5 is a fragmentary sectional view taken along the line 5-5 of Figure 4.
Description of the Preferred Embodiment ~ ~ -Turning first to Figures 1-3, a filter according to the invention is shown to comprise a housing 10 mounted on suitable legs 11 and provided with access doors 12. The housing is divided 1~; ` , ~ ` , :
by a horizontal partition or tube sheet 13 into an inlet chamber or plenum 14 and a clean air chamber or plenum 15. The lower ~ .
-~ portion of chamber 14 is formed as a hopper 16, having at its bottom a discharge valve 17 of the usual type which may be driven :~
. by a suitable motor. Air containing particulate matter is admitted ;~
to chamber 14 at an inlet 20 which includes a deflector 21 made up of a semicylinder 22 of perforated metal carrying at its end a ~`
~- disc 23 of imperforate metal preferably arranged at an angle of ; about 77 with respect to the axix of the inlet. The perforations - in semicylinder 22 may conveniently be half an inch in diameter, ~ 30 and may occupy about 50~ of the area.
.
,.............................. . .
1(169835 Partition 13 is shown as havin~ an array or apertures 24 for passage o~ air from chamber 1~ into chamber 15, from which it is removed through an outlet 25 which alc;o serves to give access to dust to chamber 15. Flow of air through the ilter may be produced by a fan or pump drawing the air from outlet 25 or forcing it into inlet 20 at the choice of the user.
In one embodiment of the invention inlet 20 had a diameter of 18 inches and outlet 25 had a diameter of 20 inches. For a flow of 6600 cubic feet per minute this resulted in inlet velocity of 3730 feet per minute and exhaust velocity of 3025 feet per minute.
Mounted in chamber 14 below the apertures in partition 13 is an array of pleated paper filter elements 26, best shown in Figures 2, 4 and 5. Each filter element is shown to comprise a hollow cylinder 27 of pleated porous paper, which is the actual filter media, the folds in the pleats running parallel to axis of the cylinderr and the first-and last pleats be~ng ` cemented or otherwise secured together as suggested at 30.
Cylinder 27 is contained between an inner screen 31 and an outer screen 32, both of perforated metal. The inner folds of the pleats are secured to the inner screen 31 at intervals of a few inches along the cylinder by beads of adhesive 33, and the outer folds are similarly secured to the outer screen 32 by beads 34. At one end of the element the screens and the pleats are secured to a ring 35 of imperforate material by adhesive 36, and at the other end the screens and the pleats are secured to a disc 37 by adhesive 40. Disc 37 has a central depression 41 which is apertured to pass a tie rod 42 secured to the disc by . .
3~
a pair of nuts ~3 and 44 and a suitable lock washer 45.
The free end of tie rod 42 threadealy engages a barrel nut 47 which is received in notchés 47 in a three legged spider 50 secured to the lower surface o- partition 13 and centered in aperture 24. As shown in Figure 5 the spider is an assembIy of two members 51 and 52 spot welded together ~-to form a generally Y-shaped unit having three legs which are welded on edge to partition 13. Near the center of the spider, where notches` 47 for barrel nut ~6 are Iocated, members 51 and 52 are bent to define a smaller U-shaped opening, the legs of which are spaced by slightly more than the diameter of '~
tie rod 42. At their outer ends the legs of spider 50 are cut away as at 53 to accomodate the inside diameter of element 26. .
Associated with each aperture is an annulus 54 of compressible material such as rubber, which makes a seal between the '~
partition and the adjacent end of the circular element when the element, and therefore rod 42, is screwed tightly into the barrel nut 46.
It will be seen that the path for air flow from '~
chamber 14 to chamber 15 is radially inward through screens 32 cylinders 27 and screens 31 of the filter elements, then through -the insides of these elements and past spiders 50. Dust and other particulate matter collects on the outer surfaces of the filter elements, and must periodically be removed to clean the elements and restore their efficiency. ..
The cleaning is accomplished by means including an ejector pump such as a venturi 55 associated with each aperture in partition 13. The venturis are located in chamber 15 and are secured to partition 13 in centered relati.on to thQ apertures ~y rivets 56. Spaced from and coaxial with the venturis are nozzles 57 through'which'short bursts of jets of' clean compressed ai`r are projected through the venturi into the filter elements in a . , : ~ ' predetermined, timed sequence. The nozzles may conveniently be no more than properly positioned radial hol~s in pipes extending laterally above the venturis.
It has been found that when sixteen Eilter elements are used, as indicated in Figure 3, efficient system operation can be accomplished when ~o eIements are cleaned at once, fourteen elements remaining in normal service. Accordingly 8 cleaning pipes 60, 61 extend into chamber 15 from a like number of solenoid valves 62 which may be energized ~o place the pipes in communication with a manifold 63 supplying air at 90-lO0 PSIG. Pipes 60 are short and straight, passing directly over the centers of venturis nearer the manifold, and pipes 61 are longer and offset to pass directly over the centers of venturis removed from the manifold. Each pipe has two nozzles, properly ; located to supply jets to its associated venturis.
; Valves 62 are connected by suitable electrical conductors 64 to a junction box 65 which contains or is suitably connected to a timer for energizing the valves in a predetermined sequence. It has been found that an electrical pulse of 50 milliseconds long results in valve opening for about l/lO of a second, and that the resulting air pulse oE
say 3/4 SCFM is brief enough and abrupt enough to have the desired cleaning effect in the two filter elements. The valves are repeatedly operated in a predetermined order. It is a matter of choice, to be deterrnined by the user, how often the cycle of operation of all eight valves takes place: they preferably operate at equal intervals, and the cycle length ;`~ may vary bet~Jeen half a minute and eight minutes or more.
Although element~ 26 are shown as of pleated paper, it will be understood that other fibrous materials, more especially non-woven materials such as felt, for example, .:
',:
3~3~
may be used.
Numexous ob~ect~ and advan~ages, o~ the in~enti.on have been set forth in the ~oregoin~ description, together with the details of the structure and ~unction o~ the invention, and th~ novel ~eatures there~ are pointed out in the appended claims. The dis,closure, ho~ever, i~ illustrat~ve onl~, and ~:~
chang.es ma~ be made in detail especiall~ in matters of shape, size, and arrangement of parts, within the princi~le of the ~: ;
invention, to the full extent indicated by the broad ~eneral meaning .;.:of the terms in wh~.ch the appended claims are expressed.
',' ~ ' ' . ' ~.
- . .
~ , . ~ .
, .~ , . 30 ~ .
There are numerous situations where a large volume of air must be treated on a continuous-basis. In order to handle several thousand cubic feet per minute a large filter area must be available, and even then a very considerable pressure drop takes place across the filter. From a practical viewpoint it is necessar~ that some form of continued cleaning of the filter medium be pro~ided, as duplication of equipment to permit shutdown for cleaning is prohibitively expensive both in cost and in space, while the period of operation of a ~ilter unit before its efficiency is reduced to an intolerable~ level by the matter accumulated thereon is not long.
A standard way of constructing air filters has been to provide a housing divided into inlet and clean air chambers by a partition having a plurality of apertures. A sock or bag of suitable fabric, often on a wire frame, is suspended in each aperture, and a suitable pump or blower causes air flow through the bags, so that the undesired particulate matter collects on the outer surfaces of the bags. Cleaning is accomplished by directing brief jets of air into the bags , a few at a time, in a predetermined sequence, thus reversing the flow through the bays and subjecting them ko a minor physical shaking. This removes the deposited material, most .. . .
. . . .
of which falls to the bottom o~ the inlet chambex for removal either intermittently or continuously with a rotary air lock, In a typical example, a filter of this sort to handle approximately 8000 cuhic feet of air perminute with a flow velocity of 8-lO cubic feet per minute per s~uare foot of area of medium,requires 770 square feet of bag surface, a total of 81 bags 4-1~2 inches in diameter and 8 feet long.
Thus even apart from the continuous cleaning component.s, the filter elements ~alone-70ccupy a housing of very considerable size.
It also became obvious very quickly that the filter bags, and their supporting frames, are bulky and awkward to ;~
deal with, difficult to install and replace, and subject to rapid wear.
Efforts have been made to find substitutes for filter bags, and some of these alternatives have been successful to a limited exten-~ in laboratory situations. Thus porus metal and ceramic media turned out to have too low a capacity, and woven metal media are prohibitively expensive. Pleated filters ; 20 made of paper ~ave some promise, but had too short a lifetime to be practical.
Summary of the Invention The present invention greatly reduces the dimensions of air filters and increases their convenience and efficiency by the use of pleated paper filter elements having special structure to extend their service life, by operating the filter elements at a derated flow velocity~ and hy providing improved means for mounting khe elements in readily replaceable ~` fashion. The elements in question were developed for the ` 30 .
' ' ' , entirel~ different field of protecking the engines of motor vehicles such as trucks and o~f-the-road vehicles ~rom road dust and other particulate matter, and accordin~ly are of suitably rugged construction for that purpose~ In their intended use, however, they were not subject to the rigors of reverse jet cleaning.
It is the discovery of this invention that these pleated paper ~ilters, when subjected to a reduced flow velocity of 1-3 cubic feet per minute per square foot of filter area, are comparable to cloth bags in volume oE air handled, that they can withstand the stresses of continuous cleaning by -reverse jets, and that they markedly reduce the total size of a filter unit, often by a factor of two. Sixteen of such elements present 3060 feet of filtering surface, in a height of 28 inches rather than 8 feet, and replace the 81 bags mentioned above. The pleated paper filters are also less expensive than the cloth bags.
It is accordingly a principal object of the invention to provide a new and improved air filter capable of handling large volumes of air while occupying a smaller space than previous filters. Another object is to provide such a filter capable of using pleated paper filter elements of improved construction. A more specific object of the invention is to provide such a filter including novel means for mounting said elements in readily replaceable ~ashion.
Accordingly, the present invention comprises, in a pulse jet cleaned air filter, the improvement which comprises a derated pleated papex filte~ element. The meaning of the term "derated" can be better understood with the a5sistance of the following explanation: In any filter design problem, the .
~LOt~9l~5 volume of air -to be filtered is a known ~uantity, and the effective porosity of the filter medium in operation on con-taminated gas is determined, somewhat pragmatically, by the nature, fineness, and concentration of the contaminant, the temperature of the air passing through the filter and any characteristics peculiar to the specific application. The porosity being known, it becomes possible to determine the area of medium required to pass the necessary volume of air. The quotient of air volume in cubic feet per minute divided by the filter area in square feet is the filter "rating" in feet per minute. The rating not only has the climensions of velocity, but is in fact a measure of the speed of air passing through the filter.
"Deratiny" a filter is simply operating it at less than its normal capacity. Practically, this means using more filter area than normal, since the total air volume cannot be reduced.
A numerical example may be instructive. Suppose it is necessary to filter 900 cubic feet of air per minute through a medium of such porosity that 100 square feet of filter area is necessary:
the filter rating and the speed of air through the filter are 9 fpm. If now the filter area is increased to 300 square feet, the functional filter rating is now 3 fpm, so that the filter - has been derated by a factor of 3, and the speed of air through the filter is reduced to 1/3 its former value. This has the further advantage of increasing the filter efficiency, since at the lower air velocity contaminant particles are less likely to be ~arried through the filter medium, and are more easily removed in cleaning.
The present invention is directed to a filter to be used in an application requiring a known volumetric filtering rate. The filter comprises, in part, a housing divided into - , - 3a -' 10~ 5 first and secon~ chambers by a parti~ion having a plurality of apertures. The filter contains a number of hollow cylindrical filter elements of pleated, porous, non-woven shee~ material (e.g. paper) of known rating-filtering capacity per unit area.
The folds between the pleats of each cylinder are arranged parallel to the axis of the cylinder. A ring and a disc of imperforate material are secured to the shells and the pleats, the ring at one end of the cylinder and the disc at the other end of the cylinder. The foregoing assists to prevent any significant movement of the material in the element and thereby maintains the rigidity and effective filtering area of the elements. The filter also includes means to removably mount a filter element in each aperture of the partition. The number of filter elements should be such as to give the filter a total capacity greater than the known volumetric rate by a factor of about four. Means are also provided to admit a fluid laden with particulate material to the first chamber.
In addition, means are provided to exhaust fluid from the second chamber whereby fluid normally flows radially through the elements and matter collects on their surfaces. Aligned with each aperture are means for providing brief pulses of fluid to the elements in a predetermined sequence in a direction opposite to the normal fluid flow. This causes the matter collected on the surfaces of the elements to be released.
The pulse generating means of the above described filter may be located in the second chamber and the filter elements in the first chamber so that the normal fluid flow through the cylinders is radially inward. Further, access means may be pravided to the interior of the housiny to enable removal and replacement of the filter e].ements. ~n addition, ~ - 3b -.
the ~irst chamber may include a hopper, a deflector, and a discharge valve serving -to receive, separate and remove particulate matter present in the fluid sought to be filtered.
It will be appreciated that the above described invention may be adapted to perform as an air cleaning apparatus. Reverse jet cleaning means are provided in the housing to periodically remove the matter collected on the filter element surfaces. This is achieved by directing brief pulses of high pressure air into the elements at pre-determined intervals in the opposite direction from thenormal air flow.
Means in the air cleanin~ apparatus are also provided for reducing the impact of ~he particulate matter on the pleated paper filter medium. This is accomplished by grossly derating the filter elements so that the particulate matter can be periodically removed during reverse jet cleaning and so that the pleated paper filter medium can withstand the stresses placed upon it by continuous reverse jet cleaning. The required means may be effected by having the plurality of filter elements possess a total filter area sufficient to reduce the velocity of air flow through each filter element to a velocity substantially lower than the normal rated velocity.
The foregoing air cleaning apparatus may be further adapted to comprise a dust collector apparatus. The reverse jet cleaning means would also include a nozzle aligned with each aperture to effect the high pressure intermittent pulse cleaning of dust from the filter element surfaces. The velocity of air flowing khrough each filter element may be between about one to three cubic feet per minute per square foot of filter area.
3c -' . - ' . .
;983~i various other objec-ts, advantages, and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part - 3d -: '` `
- ~0~ 5 hereof. However, for a better understanding of the invention, its advantages, and objects attained by its use, reference should be had to the drawing which forms a further part hereof, and to the accompanying descriptive matter, in which khere is illus-trated and described a preferred embodiment of the invention.
srief ~escription of the Drawings In the drawing Figure 1 is a front elevational view of an air filter embodying the invention, parts being broken away for clarity;
Figure 2 is a similiar side elevation;
Figure 3 is a similiar plan view;
Figure 4 is a fragmentary sectional view taken a].ong the axis of a filter element; and Figure 5 is a fragmentary sectional view taken along the line 5-5 of Figure 4.
Description of the Preferred Embodiment ~ ~ -Turning first to Figures 1-3, a filter according to the invention is shown to comprise a housing 10 mounted on suitable legs 11 and provided with access doors 12. The housing is divided 1~; ` , ~ ` , :
by a horizontal partition or tube sheet 13 into an inlet chamber or plenum 14 and a clean air chamber or plenum 15. The lower ~ .
-~ portion of chamber 14 is formed as a hopper 16, having at its bottom a discharge valve 17 of the usual type which may be driven :~
. by a suitable motor. Air containing particulate matter is admitted ;~
to chamber 14 at an inlet 20 which includes a deflector 21 made up of a semicylinder 22 of perforated metal carrying at its end a ~`
~- disc 23 of imperforate metal preferably arranged at an angle of ; about 77 with respect to the axix of the inlet. The perforations - in semicylinder 22 may conveniently be half an inch in diameter, ~ 30 and may occupy about 50~ of the area.
.
,.............................. . .
1(169835 Partition 13 is shown as havin~ an array or apertures 24 for passage o~ air from chamber 1~ into chamber 15, from which it is removed through an outlet 25 which alc;o serves to give access to dust to chamber 15. Flow of air through the ilter may be produced by a fan or pump drawing the air from outlet 25 or forcing it into inlet 20 at the choice of the user.
In one embodiment of the invention inlet 20 had a diameter of 18 inches and outlet 25 had a diameter of 20 inches. For a flow of 6600 cubic feet per minute this resulted in inlet velocity of 3730 feet per minute and exhaust velocity of 3025 feet per minute.
Mounted in chamber 14 below the apertures in partition 13 is an array of pleated paper filter elements 26, best shown in Figures 2, 4 and 5. Each filter element is shown to comprise a hollow cylinder 27 of pleated porous paper, which is the actual filter media, the folds in the pleats running parallel to axis of the cylinderr and the first-and last pleats be~ng ` cemented or otherwise secured together as suggested at 30.
Cylinder 27 is contained between an inner screen 31 and an outer screen 32, both of perforated metal. The inner folds of the pleats are secured to the inner screen 31 at intervals of a few inches along the cylinder by beads of adhesive 33, and the outer folds are similarly secured to the outer screen 32 by beads 34. At one end of the element the screens and the pleats are secured to a ring 35 of imperforate material by adhesive 36, and at the other end the screens and the pleats are secured to a disc 37 by adhesive 40. Disc 37 has a central depression 41 which is apertured to pass a tie rod 42 secured to the disc by . .
3~
a pair of nuts ~3 and 44 and a suitable lock washer 45.
The free end of tie rod 42 threadealy engages a barrel nut 47 which is received in notchés 47 in a three legged spider 50 secured to the lower surface o- partition 13 and centered in aperture 24. As shown in Figure 5 the spider is an assembIy of two members 51 and 52 spot welded together ~-to form a generally Y-shaped unit having three legs which are welded on edge to partition 13. Near the center of the spider, where notches` 47 for barrel nut ~6 are Iocated, members 51 and 52 are bent to define a smaller U-shaped opening, the legs of which are spaced by slightly more than the diameter of '~
tie rod 42. At their outer ends the legs of spider 50 are cut away as at 53 to accomodate the inside diameter of element 26. .
Associated with each aperture is an annulus 54 of compressible material such as rubber, which makes a seal between the '~
partition and the adjacent end of the circular element when the element, and therefore rod 42, is screwed tightly into the barrel nut 46.
It will be seen that the path for air flow from '~
chamber 14 to chamber 15 is radially inward through screens 32 cylinders 27 and screens 31 of the filter elements, then through -the insides of these elements and past spiders 50. Dust and other particulate matter collects on the outer surfaces of the filter elements, and must periodically be removed to clean the elements and restore their efficiency. ..
The cleaning is accomplished by means including an ejector pump such as a venturi 55 associated with each aperture in partition 13. The venturis are located in chamber 15 and are secured to partition 13 in centered relati.on to thQ apertures ~y rivets 56. Spaced from and coaxial with the venturis are nozzles 57 through'which'short bursts of jets of' clean compressed ai`r are projected through the venturi into the filter elements in a . , : ~ ' predetermined, timed sequence. The nozzles may conveniently be no more than properly positioned radial hol~s in pipes extending laterally above the venturis.
It has been found that when sixteen Eilter elements are used, as indicated in Figure 3, efficient system operation can be accomplished when ~o eIements are cleaned at once, fourteen elements remaining in normal service. Accordingly 8 cleaning pipes 60, 61 extend into chamber 15 from a like number of solenoid valves 62 which may be energized ~o place the pipes in communication with a manifold 63 supplying air at 90-lO0 PSIG. Pipes 60 are short and straight, passing directly over the centers of venturis nearer the manifold, and pipes 61 are longer and offset to pass directly over the centers of venturis removed from the manifold. Each pipe has two nozzles, properly ; located to supply jets to its associated venturis.
; Valves 62 are connected by suitable electrical conductors 64 to a junction box 65 which contains or is suitably connected to a timer for energizing the valves in a predetermined sequence. It has been found that an electrical pulse of 50 milliseconds long results in valve opening for about l/lO of a second, and that the resulting air pulse oE
say 3/4 SCFM is brief enough and abrupt enough to have the desired cleaning effect in the two filter elements. The valves are repeatedly operated in a predetermined order. It is a matter of choice, to be deterrnined by the user, how often the cycle of operation of all eight valves takes place: they preferably operate at equal intervals, and the cycle length ;`~ may vary bet~Jeen half a minute and eight minutes or more.
Although element~ 26 are shown as of pleated paper, it will be understood that other fibrous materials, more especially non-woven materials such as felt, for example, .:
',:
3~3~
may be used.
Numexous ob~ect~ and advan~ages, o~ the in~enti.on have been set forth in the ~oregoin~ description, together with the details of the structure and ~unction o~ the invention, and th~ novel ~eatures there~ are pointed out in the appended claims. The dis,closure, ho~ever, i~ illustrat~ve onl~, and ~:~
chang.es ma~ be made in detail especiall~ in matters of shape, size, and arrangement of parts, within the princi~le of the ~: ;
invention, to the full extent indicated by the broad ~eneral meaning .;.:of the terms in wh~.ch the appended claims are expressed.
',' ~ ' ' . ' ~.
- . .
~ , . ~ .
, .~ , . 30 ~ .
Claims (14)
1. A filter for use in an application requiring a known volumetric filtering rate comprising, in combination:
a housing;
a partition dividing said housing into first and second chambers, and having a plurality of apertures, a like plurality of filter elements each comprising a hollow cylinder of pleased, porous, non-woven sheet material of known rating - filtering capacity per unit area - arranged with the folds between the pleats parallel to the axis of the cylinder, a ring of imperforate material secured to the shells and the pleats at one end of the cylinder, and a disc of im-perforate material secured to the shells and the pleats at the other end of the cylinder, all whereby to prevent any significant movement of the material in the element and hence to maintain the rigidity and effective filtering area of the elements;
means removably mounting a filter element in each aperture in said partition, the total number of said elements being such as to give the filter a total capacity greater than said known volumetric rate by a factor of about four;
means admitting a fluid laden with particulate material to the first chamber;
means exhausting fluid from the second chamber, whereby fluid normally flows radially through said elements and said matter collects on the surfaces of said elements;
and means aligned with each aperture for providing brief pulses of fluid to said elements in a predetermined sequence in a direction opposite to that of the normal fluid flow, to release from the surfaces of said elements the matter collected thereon.
a housing;
a partition dividing said housing into first and second chambers, and having a plurality of apertures, a like plurality of filter elements each comprising a hollow cylinder of pleased, porous, non-woven sheet material of known rating - filtering capacity per unit area - arranged with the folds between the pleats parallel to the axis of the cylinder, a ring of imperforate material secured to the shells and the pleats at one end of the cylinder, and a disc of im-perforate material secured to the shells and the pleats at the other end of the cylinder, all whereby to prevent any significant movement of the material in the element and hence to maintain the rigidity and effective filtering area of the elements;
means removably mounting a filter element in each aperture in said partition, the total number of said elements being such as to give the filter a total capacity greater than said known volumetric rate by a factor of about four;
means admitting a fluid laden with particulate material to the first chamber;
means exhausting fluid from the second chamber, whereby fluid normally flows radially through said elements and said matter collects on the surfaces of said elements;
and means aligned with each aperture for providing brief pulses of fluid to said elements in a predetermined sequence in a direction opposite to that of the normal fluid flow, to release from the surfaces of said elements the matter collected thereon.
2. Apparatus according to claim 1 in which the last named means is located in the second chamber and said filter elements are located in the first chamber, so that the normal fluid flow through said cylinders is radially inward.
3. Apparatus according to claim 1 together with means giving access to the interior of said housing to enable removal and replacement of said filter elements.
4. Apparatus according to claim 1 in which the pleated material of said filter elements is paper.
5. Apparatus according to claim 1 in which the first chamber includes a hopper for receiving matter released from said surfaces and a discharge valve for continuously removing matter from said hopper.
6. Apparatus according to claim 6 in which the first chamber includes a deflector for directing the flow of fluid and removing a considerable initial portion of said matter from the fluid by inertial separation.
7. Apparatus for cleaning air at a predetermined rate in terms of volume per unit time, comprising in combination with a housing:
means forming first and second chambers in said housing including a partition having a plurality of apertures therein;
means for admitting said air into said first chamber, and means for exhausting air from said second chamber, whereby air normally flows through said apertures and through said second chamber at said predetermined rate;
a like plurality of hollow filter elements each capable of providing a normal filtering function, each comprising a pleated porous paper filter medium and having an open end and a closed end, and each filter element having a rated velocity for its normal filtering function and a known filter area;
means mounting said filter elements in the first chamber with their open ends communicating with said apertures so that said air normally flows radially through said filter elements at said predetermined rate and particulate matter carried by the air collects on surfaces of said elements;
reverse jet cleaning means in said housing for periodically removing the matter collected on surfaces of said filter elements by directing brief pulses of air at high pressure into said elements at predetermined intervals in a direction opposite to that of the normal air flow; and means for reducing the impact of the particulate matter on said pleated paper filter medium by grossly derating said filter elements so that the particulate matter can be periodically removed during reverse jet cleaning and said pleated paper filter medium can withstand the stresses placed upon said pleated paper filter medium by continuous reverse jet cleaning comprising said plurality of filter elements having a total filter area sufficient to reduce the velocity of air flow through each filter element to a velocity substantially lower than said normal rated velocity.
means forming first and second chambers in said housing including a partition having a plurality of apertures therein;
means for admitting said air into said first chamber, and means for exhausting air from said second chamber, whereby air normally flows through said apertures and through said second chamber at said predetermined rate;
a like plurality of hollow filter elements each capable of providing a normal filtering function, each comprising a pleated porous paper filter medium and having an open end and a closed end, and each filter element having a rated velocity for its normal filtering function and a known filter area;
means mounting said filter elements in the first chamber with their open ends communicating with said apertures so that said air normally flows radially through said filter elements at said predetermined rate and particulate matter carried by the air collects on surfaces of said elements;
reverse jet cleaning means in said housing for periodically removing the matter collected on surfaces of said filter elements by directing brief pulses of air at high pressure into said elements at predetermined intervals in a direction opposite to that of the normal air flow; and means for reducing the impact of the particulate matter on said pleated paper filter medium by grossly derating said filter elements so that the particulate matter can be periodically removed during reverse jet cleaning and said pleated paper filter medium can withstand the stresses placed upon said pleated paper filter medium by continuous reverse jet cleaning comprising said plurality of filter elements having a total filter area sufficient to reduce the velocity of air flow through each filter element to a velocity substantially lower than said normal rated velocity.
8. Dust collector apparatus for cleaning air at a predetermined rate in terms of volume per unit time, comprising in combination:
means forming a chamber including a sheet having a plurality of apertures therein for admitting air into said chamber;
means for exhausting air from said chamber, whereby air normally flows through said apertures and said chamber at said predetermined rate;
a like plurality of hollow filter elements each capable of providing a normal filtering function, each comprising a pleated porous paper filter and having a closed end and an open end, and each filter element having a known filter area and a rated velocity for its normal filtering function;
means mounting said filter elements with their open ends communicating with said apertures so that said air normally flows radially through said filter elements at said predetermined rate and dust in the air collects on surfaces of said elements;
reverse jet cleaning means in said chamber, including a nozzle aligned with each said aperture, for periodically remov-ing the dust collected on surfaces of said filter elements by directing brief pulses of air at high pressure into said elements at predetermined intervals in a direction opposite to that of the normal air flow;
said plurality of filter elements having a total filter area sufficient to reduce the velocity of air flowing through each filter element to approximately one-quarter of said normal rated velocity to reduce the impact of said dust on said pleated filters so that the dust can be periodically removed during reverse jet cleaning and the filter elements can withstand the stresses placed upon said pleated paper filters by the reverse jet cleaning.
means forming a chamber including a sheet having a plurality of apertures therein for admitting air into said chamber;
means for exhausting air from said chamber, whereby air normally flows through said apertures and said chamber at said predetermined rate;
a like plurality of hollow filter elements each capable of providing a normal filtering function, each comprising a pleated porous paper filter and having a closed end and an open end, and each filter element having a known filter area and a rated velocity for its normal filtering function;
means mounting said filter elements with their open ends communicating with said apertures so that said air normally flows radially through said filter elements at said predetermined rate and dust in the air collects on surfaces of said elements;
reverse jet cleaning means in said chamber, including a nozzle aligned with each said aperture, for periodically remov-ing the dust collected on surfaces of said filter elements by directing brief pulses of air at high pressure into said elements at predetermined intervals in a direction opposite to that of the normal air flow;
said plurality of filter elements having a total filter area sufficient to reduce the velocity of air flowing through each filter element to approximately one-quarter of said normal rated velocity to reduce the impact of said dust on said pleated filters so that the dust can be periodically removed during reverse jet cleaning and the filter elements can withstand the stresses placed upon said pleated paper filters by the reverse jet cleaning.
9. Apparatus for cleaning air at a predetermined rate in terms of volume per unit time, comprising in combination:
means forming a chamber including a sheet having a plurality of apertures therein for admitting air into said chamber;
a like plurality of hollow filter elements each capable of providing a normal filtering function, each comprising a pleated porous paper filter and having a closed end and an open end, and each filter element having a rated velocity for its normal filtering function and a known filter area;
means mounting said filter elements with their open ends communicating with said apertures;
means for exhausting air from said chamber so that said air normally flows radially through said filter elements at said predetermined rate and particulate matter carried by the air collects on surfaces of said elements;
reverse jet cleaning means in said chamber for period-ically removing the matter collected on surfaces of said filter elements by directing brief pulses of air at high pressure into said elements at predetermined intervals in a direction opposite to that of the normal air flow; and means for reducing the impact of the particulate matter on said pleated filters, including grossly derating said filter elements so that the particulate matter can be periodically removed during reverse jet cleaning and said pleated paper filters can withstand the stresses placed upon them by the reverse jet cleaning, comprising said plurality of filter ele-ments having a total filter area sufficient to reduce the velocity of air flow through each filter element to a velocity substantially lower than said normal rated velocity.
means forming a chamber including a sheet having a plurality of apertures therein for admitting air into said chamber;
a like plurality of hollow filter elements each capable of providing a normal filtering function, each comprising a pleated porous paper filter and having a closed end and an open end, and each filter element having a rated velocity for its normal filtering function and a known filter area;
means mounting said filter elements with their open ends communicating with said apertures;
means for exhausting air from said chamber so that said air normally flows radially through said filter elements at said predetermined rate and particulate matter carried by the air collects on surfaces of said elements;
reverse jet cleaning means in said chamber for period-ically removing the matter collected on surfaces of said filter elements by directing brief pulses of air at high pressure into said elements at predetermined intervals in a direction opposite to that of the normal air flow; and means for reducing the impact of the particulate matter on said pleated filters, including grossly derating said filter elements so that the particulate matter can be periodically removed during reverse jet cleaning and said pleated paper filters can withstand the stresses placed upon them by the reverse jet cleaning, comprising said plurality of filter ele-ments having a total filter area sufficient to reduce the velocity of air flow through each filter element to a velocity substantially lower than said normal rated velocity.
10. Apparatus for cleaning air at a predetermined rate in terms of volume per unit time, comprising in combination:
means forming a chamber including a sheet having a plurality of apertures therein for admitting air into said chamber;
a like plurality of hollow filter elements each capable of providing a normal filtering function, each comprising a pleated porous paper filter and having a closed end and an open end, and each filter element having a known filter area;
means mounting said filter elements with their open ends communicating with said apertures;
means for exhausting air from said chamber so that said air normally flows radially through said filter elements at said predetermined rate and particulate matter carried by the air collects on surfaces of said elements;
reverse jet cleaning means in said chamber for period-ically removing the matter collected on surfaces of said filter elements by directing brief pulses of air at high pressure into said elements at predetermined intervals in a direction opposite to that of the normal air flow; and means for grossly derating said filter elements compris-ing said plurality of filter elements having a total filter area sufficient to reduce the velocity of air flow through each filter element to a velocity at which said pleated paper filters can withstand the stresses placed upon them by the reverse jet clean-ing.
means forming a chamber including a sheet having a plurality of apertures therein for admitting air into said chamber;
a like plurality of hollow filter elements each capable of providing a normal filtering function, each comprising a pleated porous paper filter and having a closed end and an open end, and each filter element having a known filter area;
means mounting said filter elements with their open ends communicating with said apertures;
means for exhausting air from said chamber so that said air normally flows radially through said filter elements at said predetermined rate and particulate matter carried by the air collects on surfaces of said elements;
reverse jet cleaning means in said chamber for period-ically removing the matter collected on surfaces of said filter elements by directing brief pulses of air at high pressure into said elements at predetermined intervals in a direction opposite to that of the normal air flow; and means for grossly derating said filter elements compris-ing said plurality of filter elements having a total filter area sufficient to reduce the velocity of air flow through each filter element to a velocity at which said pleated paper filters can withstand the stresses placed upon them by the reverse jet clean-ing.
11. The apparatus of claim 10 wherein the velocity of air flowing through each filter element is between about one to three cubic feet per minute per square foot of filter area.
12. The apparatus of claim 10 wherein the total filter area is increased by a factor of about four as compared to filters used at normal rated velocities.
13. The apparatus of claim 10 wherein the velocity of air flowing through each filter element is about two feet per minute.
14. The apparatus of claim 10 wherein each filter element has a rated velocity for its normal filtering function and the velocity is reduced to approximately one-quarter of said normal rated velocity.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US48621574A | 1974-07-05 | 1974-07-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1069835A true CA1069835A (en) | 1980-01-15 |
Family
ID=23931045
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA230,345A Expired CA1069835A (en) | 1974-07-05 | 1975-06-27 | Dust collector |
Country Status (9)
| Country | Link |
|---|---|
| JP (2) | JPS6012886B2 (en) |
| BR (1) | BR7504216A (en) |
| CA (1) | CA1069835A (en) |
| DE (2) | DE7520127U (en) |
| ES (1) | ES439138A1 (en) |
| FR (1) | FR2276861A1 (en) |
| GB (1) | GB1516721A (en) |
| IT (1) | IT1040808B (en) |
| ZA (1) | ZA754327B (en) |
Families Citing this family (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6012886B2 (en) * | 1974-07-05 | 1985-04-04 | ダナルドソン、カムパニ、インコーパレイテイド | Air cleaning device with reverse jet cleaning means |
| JPS5631311Y2 (en) * | 1977-01-28 | 1981-07-25 | ||
| JPS5423267A (en) * | 1977-07-21 | 1979-02-21 | Nippon Seimitsu Kogyo | Dusting device |
| US4174204A (en) * | 1978-08-04 | 1979-11-13 | Donaldson Company, Inc. | Pulse jet cleaned air filter assembly with integral air compressor |
| US4214882A (en) * | 1978-08-08 | 1980-07-29 | Donaldson Company, Inc. | Portable air filter assembly with pulse jet self-cleaning filters |
| CA1133691A (en) * | 1978-11-20 | 1982-10-19 | Gunter J. Lissy | Powder spray booth |
| US4272262A (en) * | 1979-09-27 | 1981-06-09 | American Air Filter Company, Inc. | Gas-separation filter device |
| SE421488B (en) * | 1979-11-16 | 1982-01-04 | Loeoef Ingemar | FILTER RECOVERY FOR RECOVERY OF MATERIAL MATERIAL CURRENT OF A AIR FLOW FROM A SPRAYBOX |
| JPS57173819U (en) * | 1981-04-23 | 1982-11-02 | ||
| JPS6287724U (en) * | 1985-11-21 | 1987-06-04 | ||
| JPS6320922U (en) * | 1986-07-24 | 1988-02-12 | ||
| GB2250454B (en) * | 1988-09-16 | 1993-03-03 | Atomic Energy Authority Uk | Air filter |
| JP2010240524A (en) * | 2009-04-01 | 2010-10-28 | Amc:Kk | Cartridge filter element for filtration |
| CN102390692A (en) * | 2011-07-07 | 2012-03-28 | 昆明冶金研究院 | Dust catcher for belt conveyor with large inclined angle |
| US8673037B2 (en) | 2011-10-18 | 2014-03-18 | Camfil Farr, Inc. | Air filter with balanced seal |
| CN103405967A (en) * | 2013-08-16 | 2013-11-27 | 山东天元压力容器有限公司 | Melamine hot gas filter |
| US20160303501A1 (en) | 2015-04-16 | 2016-10-20 | Clark Filter, Inc. | End cap and air filter incorporating same |
| KR20240005169A (en) * | 2016-05-13 | 2024-01-11 | 도날드슨 컴파니, 인코포레이티드 | Filter medium |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS545052B2 (en) * | 1972-02-08 | 1979-03-13 | ||
| JPS6012886B2 (en) * | 1974-07-05 | 1985-04-04 | ダナルドソン、カムパニ、インコーパレイテイド | Air cleaning device with reverse jet cleaning means |
-
1975
- 1975-06-24 JP JP50078489A patent/JPS6012886B2/en not_active Expired
- 1975-06-25 DE DE19757520127U patent/DE7520127U/en not_active Expired
- 1975-06-25 DE DE19752528220 patent/DE2528220A1/en active Pending
- 1975-06-27 CA CA230,345A patent/CA1069835A/en not_active Expired
- 1975-07-02 FR FR7520755A patent/FR2276861A1/en active Granted
- 1975-07-02 GB GB27834/75A patent/GB1516721A/en not_active Expired
- 1975-07-03 IT IT50339/75A patent/IT1040808B/en active
- 1975-07-04 ES ES439138A patent/ES439138A1/en not_active Expired
- 1975-07-04 BR BR5396/75D patent/BR7504216A/en unknown
- 1975-07-07 ZA ZA754327A patent/ZA754327B/en unknown
-
1980
- 1980-04-01 JP JP4126180A patent/JPS56129024A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| ZA754327B (en) | 1977-02-23 |
| BR7504216A (en) | 1976-05-25 |
| FR2276861A1 (en) | 1976-01-30 |
| IT1040808B (en) | 1979-12-20 |
| ES439138A1 (en) | 1977-06-01 |
| DE7520127U (en) | 1976-04-22 |
| JPS6012886B2 (en) | 1985-04-04 |
| JPS5133361A (en) | 1976-03-22 |
| DE2528220A1 (en) | 1976-01-22 |
| JPS56129024A (en) | 1981-10-08 |
| FR2276861B1 (en) | 1977-07-08 |
| GB1516721A (en) | 1978-07-05 |
| AU8258375A (en) | 1977-01-20 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |