JP2948243B2 - HEPA air filter for high temperature environment and manufacturing method thereof - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-efficiency air filter, and more particularly to an assembly of a filter core and a frame suitable for use in a high-temperature environment.

Conventional technology So-called HEPA (High Efficiency Particulate Air)
Type air filter must be operated with an airborne particle removal efficiency of 99.97% or more, but in the general structure of this type of filter, the filter core bends a continuous thin filter medium in a zigzag shape, and each pleat faces each other. A thin corrugated spacer plate is arranged between the walls to form a plurality of accordion fleets of equal dimensions.

The filter core is supported in sealing engagement with a box-shaped frame surrounding the filter core over the entire circumference including the pleats at both ends and the entire length of the edge of the filter medium. In this case, complete sealing between the filter core and the frame is important in preventing unfiltered air from bypassing the filter.

Depending on the application, this type of air filter is, for example, 53
Installed in a location exposed to high temperatures of 7.8 ° C (generally 1000 ° F). Problems typically encountered with filter assemblies used under such conditions include separation between the encapsulant and the frame member and associated air leakage, cracks in the encapsulant, and powdering of the adhesive or There is crushing. These problems are believed to be due to the high temperatures and the lack of strength of the structure of the filter assembly, and are due to differences in the coefficients of thermal expansion, insufficient adhesion, and insufficient strength.

An early approach to solving the problem of providing the necessary seal between the filter core and the frame to withstand high temperatures is disclosed in U.S. Pat. No. 2,884,091 to Baldwin.

Another filter structure intended for use at elevated temperatures is disclosed in U.S. Pat. No. 4,199,387 to Ladike.

On the other hand, a filter structure and a method of assembling the filter structure in which the zigzag edge of the filter medium is dipped in a liquid sealant and the sealant is cured to seal the space between the filter medium and the frame are disclosed in U.S. Pat. U.S. Patent No. 4,227,953.

In the structure disclosed in the aforementioned U.S. Pat.No. 2,884,091,
An elastic mat or fabric insulation made of fine glass fibers is compression inserted between the filter core and the surrounding metal frame. However, at 537.8 ° C (generally 1000 ° F
After prolonged exposure to high temperatures, tempering occurs in the glass fibers, causing the mat to lose its elasticity, resulting in air leakage between the filter core and the frame.

The technique disclosed in the above-mentioned U.S. Pat. No. 4,199,387 includes a step of applying a ceramic-based adhesive to a zigzag edge of a filter medium and a spacer member sandwiched between the filter media using a gold iron.

The U.S. Pat.No. 3,581,479 discloses that grooves or channels are formed on the inner surfaces of upper and lower frame members, a long nozzle is inserted into the groove or the like, and the liquid adhesive is applied to the nozzle when the nozzle is pulled out of the groove. Inject through.

The method of assembling the filter of U.S. Pat.No. 4,227,953,
A step of filling a shallow dish with a liquid adhesive and dipping a zigzag edge of the pleated filter medium in the adhesive. The lower member of the shallow dish becomes the end of the case of the filter, and the side member adheres to the end pleat of the filter medium so as to be in close contact with the end member of the case.

Means for Solving the Problems It is a main object of the present invention to provide a structure of an HEPA type air filter capable of maintaining structural rigidity and filtration efficiency even when exposed to a high temperature for a relatively long time. .

Another object of the present invention is to provide a high-efficiency air filter having an improved means for enabling a filter medium formed with accordion pleats to be tightly engaged with the surrounding frame all around and maintained effectively at normal and high temperatures. It is.

It is a further object of the present invention to enhance the ability of the frame to initially seal and engage a pleated filter core with a sealant that is initially liquid and hardens into an air-impermeable solid. An object of the present invention is to provide a frame structure of an air filter having the same.

Others will be self-explanatory on some other occasions, and others will become apparent from the description below.

The filter structure of the present invention includes a conventional filter core comprising a sheet-like filter medium having a continuous accordion pleat with a corrugated spacer member disposed between opposing walls of each pleat in both the upstream and downstream directions of the airflow. The filter core is hermetically supported in an enclosing frame including a general side case member and end (upper and lower) case members. These side and end case members are held together with the filter core by a high strength and heat resistant adhesive. These members forming the frame are preferably made of a material which is also suitable for high-temperature applications, for example a plate of calcium silicate which is easy to machine.

The end case member is machined into a shallow dish and has a central recess bounded by a relatively narrow side wall. The end case member is machined to be deeper with mortises extending along both ends of the recess, and extends between and communicates with the deeply machined mortises at each end of the recess. Parallel grooves are machined. These grooves have a groove cross section that is wider at the bottom than at the top of the opening.

The side case member is machined so that the tenon extending from each end face is dimensioned to fit into the deepest mortise at both ends of the concave portion of the end case member. The filter unit is configured such that each outer surface of the pleat at the end of the filter medium is adhered to the inner surface of the side case member in an adhesive manner, and the liquid is contained in a concave portion including the deepest mortise and a groove at both ends of the end case member. Fill with sealant and assemble. The zigzag edge of the filter medium and the edge of the spacer member at one end of the filter core are arranged in the recess, and the tenons at both ends of the side case member are inserted into the deepest mortises at both ends of the recess. Then, the sealant is solidified to house the end and tenon of the filter core in the end case member, and a mortise joint is formed between both ends of the end case member and the side case member.

Next, the concave portion of the second end case member is filled with the liquid sealant, the intermediate assembly is inverted, and the tenon of the opposite end of the filter core and the tenon of the side case member are inserted into the concave portion. The assembly is completed when the sealant of the second end case member is hardened.

In accordance with the present invention, an air filter assembly includes: a) forming a plurality of adjacent pleats having a zigzag edge on two opposite sides and a flat panel on the other two opposite sides. A filter core comprising a single sheet of air permeable filter media folded in accordion form and spacers disposed between opposing walls of the continuous pleats; b) airtightly engaging the filter media from four sides A box-shaped frame surrounding the assembly and defining an airflow opening extending between an upstream side and a downstream side of the assembly; i) a pair of frames each having a length L, a width W, and a thickness T; Ii) formed at both ends of each of said side casings;
A tenon having a length L ', a width W', and a thickness T ', respectively; iii) a pair of identical and generally rectangular end casings having a length l, a width w, and a thickness t; iv) said ends. A recess formed on each main surface of the end casing and inward from the periphery of the end casing, wherein the recess has a generally uniform depth d from the main surface, and each side of the end casing A mortise having a generally uniform depth D 'greater than the depth d from the major surface at each end of the end casing, the mortise bordering a wall comprising the outer edge of the end casing at a portion thereof. V) a plurality of grooves, wherein each groove has an opening portion communicating with the concave portion, and the groove has a substantially uniform depth D greater than the depth d from the main surface. A bottom having a plurality of grooves, the plurality of grooves communicating with the mortise at both ends thereof, C) an outer surface of the panel-like portion of the air-permeable filter medium is hermetically sealed to an opposing inner surface of the side casing, and the zigzag edge of the filter medium. Is located in the recess, the tenon of the side casing is located in the mortise at both ends of the recess, thereby forming a mortise joint between the side casing and the end casing; d. A) a solid adhesive filled in each of the concave portion, the mortise, and the groove of the end casing, wherein the solid adhesive wraps the zigzag edge and the tenon; And the air filter assembly comprising:

According to another aspect of the invention, there is provided an air filter assembly comprising: a) a plurality of adjacent filters having zigzag edges on two opposite sides and a flat panel on the other two opposite sides. A filter core comprising: a single sheet of air permeable filter material folded in an accordion to form a pleated sheet; and a spacer disposed between opposing walls of the continuous pleats. A box-shaped frame surrounding the surface in airtight engagement to define an airflow opening extending between the upstream and downstream sides of the assembly; i) opposing an outer surface of the flat panel portion; A pair of identical and generally rectangular side casings having an inner surface that hermetically adhesively engages the outer surface; ii) an end casing having substantially the same width as the side casing; Right angle between side casing and end A pair of identical and generally rectangular end casings disposed to form the box-shaped frame; iii) recesses formed in opposing inner surfaces of the end casings, the recesses being the air permeable filter media. And iv) a mortise joint extending from each end of the side casing into the recess and adjacent end of the side and end casings. And c) a solid adhesive filled in at least one of the recesses to completely embed the zig-zag edge and the tenon. 3D is obtained.

According to yet another aspect of the present invention, there is provided a method of manufacturing an air filter assembly, comprising: a) folding a single sheet of air permeable filter material into an accordion shape and forming a zigzag shape on a common surface of two opposing ends. B) providing a plurality of adjacent pleats each having a flat panel-like portion on the other two opposite sides; b) forming a pair of identical and generally rectangular side casings, the smaller of said side casings; Forming said side casing having a width and a thickness and having a tenon extending outwardly from each end of said side casing; c) forming a pair of identical and generally rectangular end casings; The recess having a width equal to the side casing and a recess formed in the main surface of the end casing, each of the side and the end having the recess bordering the outer peripheral side wall of the end casing. End casing D) adhesively fixing the flat panel-shaped portion to the inner surface of the side casing in an airtight manner, and e) a fluidity capable of solidifying the concave portion of one of the end casings. F) arranging the side casing such that one end casing and one end are at an angle of 90 degrees with each other, the tenon at one end of each of the side casings and the filter medium; G) fully embedding the zigzag edge at one end of the adhesive in the adhesive; g) fully curing the adhesive in the one end casing until it is non-flowable; Filling the recess of the end casing with the liquid adhesive; i) inverting the filter medium, the side casing, and one end casing, and replacing the side casing with the other end casing; 90 degrees end to end So that the tenon at the other end of each of the side casings and the zigzag edge at the other end of the filter media are completely embedded in the adhesive; j) the end casings A method of manufacturing the air filter assembly, comprising curing each of the adhesives to a solid state.

The present invention will be described below with reference to the drawings.

FIG. 1 shows a conventional filter core, generally designated by the reference numeral 10, comprising a continuous filter media 12 formed in a plurality of identically sized accordion pleats folded in a zigzag. This filter medium 12 has a spacer member 14 disposed between opposing and continuous wall surfaces of the continuous pleats. Although the spacer member 14 is not shown in FIG.
This is shown in FIGS. 4 and 7. In the filter structure of the present invention, the filter medium 12 is preferably made of glass fiber, and the spacer member 14 is preferably made of corrugated aluminum or stainless steel foil. The material and manufacturing method of the filter core are the same as the conventional one.

The filter core 10 is composed of a pair of side case members 18 having the same shape.
The four sides are surrounded by a frame 16 composed of a pair of end case members 20 having the same shape. Both the side and end case members 18 and 20 are, for example, 648.89.
Manufactured from refractory materials that are dimensionally stable at temperatures below 1200 ° C (1200 ° F). The material must also be readily machinable, a suitable method for forming the side and end case members 18, 20 into the desired shape. Such materials include, for example, Jones
There is a plate made of calcium silicate manufactured by Manville under the trademark "Marinite 1".

As shown in FIG. 2 and FIG.
Machine a rectangular piece of length L, width W, and thickness T to provide tenons 22 of length L ', width W', and thickness T 'at each end. The end case member 20 also has a length l, a width w,
And a rectangular material piece having a thickness t (see FIG. 1).

The central concave portion 24 forms a main surface by machining each end case member 20 to a depth d so that the side portion and the end portion are in contact with the wall 26 and the wall 27, respectively (see FIG. 6). ). The end case member 20 is further machined in its recess 24,
A mortise 28 extending along each end of the recess 24 and a plurality of parallel grooves 30 extending between the two mortises 28 and communicating with them at both ends.
Is provided. As shown in FIG. 7, groove 30 is preferably recessed
At a depth D at least twice the depth d of 24, and a mortise 28
Is machined to a depth D 'that is deeper than the depth D of the groove. The groove 30 has a bottom surface 32 wider than the open upper surface 34 and communicates directly with the recess 24 through the open upper surface 34.

To assemble the components of the filter core 10 and the frame 16, the outer surfaces of the flaps or pleats 12 ′ of the filter medium 12 on each surface of the filter core 10 are fixed to the corresponding inner surfaces of the side case members 18 in an airtight manner. . As shown in FIG.
The height of the filter core 10 is equal to the length L of the side cable member 18 plus the depth of the central recess 24 of the case member d20 at both ends.

The recess 24 including the mortise 28 and the groove 30 of the one end case member 20 is filled with a liquid or slurry-like curable adhesive to approximately the height of the walls 26 and 27. This adhesive may be the same adhesive used to hermetically seal the pleats 12 'at both ends to the side case member 18, such as that sold by Soleilson of Pittsburgh, Pennsylvania, USA as adhesive # 360. It is preferable to use high-strength, high-heat-resistant inorganic sodium silicate as a main component. Such an adhesive has a concentration similar to that of a wet mortar and has a high viscosity even in a flowable state. Then
The zigzag edge of the filter medium 12 on one side of the filter core 10 is recessed
Soak in the adhesive in 24. The tenon 22 at one end of each end case member 18 is similarly dipped. Mortise 22 extends into mortise 28 and forms a mortise joint between side and end case members 18,20. Since the inclined surface 35 is provided, when the side and end case members 18 and 20 are joined, the adhesive easily flows out from the joined portion.

The relative dimensions of the side and end case members 18, 20 are
Is set so that the end surface of the side case member 18 adjacent to the tenon 22 is seated on the end wall 27 of the end case member 20 in a state of contacting the inner surface of the end wall 27 of the end case member 20. Is preferred. The widths of the side and end case members 18, 20 are equal (W = w), and similarly, the mortise 22 and the mortise hole 28 are also equal (W '= w'). Also, the side and end case members 18, 20
Are equal (T = t), and the thickness of the tenon 22 is half the thickness of the case member 18. The thickness of the tenon 22 is, as shown by 1 / 2t in FIG.
It also corresponds to the thickness. The radius of one side of each end of the tenon 22 is equal to the radius of both ends of the tenon 28, and the length (L ') of the tenon 22 is smaller than the depth of the tenon 28 (L'<
D '). Therefore, as shown in FIG. 7, the tenon 22 does not extend completely to the lower surface of the mortise 28, but also occupies a portion slightly larger than half of its plan view area.

After the adhesive has hardened sufficiently so as not to flow out of the end case member 20, the recesses 24 of the second end case member 20 including the grooves 30 and the mortise holes 28 are also substantially covered with the same liquid adhesive as the walls 26. And fill to a height of 27. The assembly comprising the filter core 10, the side case members 18 and the one end case member 20 is turned over after the adhesive is cured, and the zigzag edge on the opposite side of the filter medium 12 and the side case adjacent thereto are removed. The tenon 22 of the member 18 is dipped in the adhesive in the second end case member 20. After completion of the assembly in other ways, the adhesive may be applied in strips and beads along each side edge where the end flap of the filter media 12 matches the side casing. It is preferable to apply such a bead-like adhesive to the downstream surface of the filter unit as shown by the thick line 37 in FIG. The bead-like adhesive preferably extends to and surrounds the edge of the outermost corrugated spacer member on each side of the filter unit. When the adhesive cures, the assembly of the filter unit is completed and ready for use.

The state of the adhesive inside the end case member 20 is shown in FIGS. 6 and 7. FIG. The adhesive in the recess 24 in which the edge of the filter medium 12 is embedded is indicated by reference numeral 36, and the adhesive in the mortise 28 and the groove 30 is indicated by reference numerals 38 and 40, respectively. The different parts of the adhesive are indicated using different reference numbers, but the grooves 30
Communicates with the recess 24 through its open side 34 and at both ends with the mortise 28, so that the mortise 28
Therefore, the adhesive in each end case member 20 is formed into one continuous mass as a whole.

The relationship between the length (L and l) of the side case member 18 and the end case member 20 may be any ratio as long as it defines a square or rectangular air flow opening, Although the width of the case member 18 and the width of the case member 20 are equal to each other, filter units having various depths can be provided by changing the values.

For example, 60.56cm x 60.56cm x 30.48cm (24
For a filter unit of inches x 24 inches x 12 inches, typical dimensions are L = 58.89 cm (23.188 inches), 1
= 68.80 cm (23.938 inches) and W = w = 29.21 cm (1
1.5 inches).

Nominal dimensions 30.48cm x 30.48cm x 15.24cm (12 inches x 12
For inches by 6 inches units, typical dimensions are L = 28.42 cm (11.188 inches), l = 30.32 cm (11.938 inches), and W = w = 6. Other dimensions are constant regardless of the nominal outer dimensions of the filter unit, for example, T = t = 1 '= 1.91 cm, (0.750 inch), (0.375 inch), W ′ = w ′ = W−2.22 cm (0.876 inch) (1.11 cm (0.438 inch) on each side), d = 0.48 cm (0.1
88 inches), and D = 1.11 cm (0.438 inches), area 28
The radius of each end and the radius of each end 1 of handle 2 are 0.95 cm (0.37
5 inches), the width of the groove 30 is 0.95 cm (0.375) at the open top
Inches) and 1.27 cm (0.500 inches) at the bottom and walls 27
The width of (0.375 inch) and the width of wall 26 is 0.64 cm (0.250 inch)
It is.

The outer groove 30 is located 1.5 inches inward from the outer edge of the end case member 20 parallel thereto, and the third groove 30 is located between the outer edges of the member 20 and thus 2 inches. It is located in the center between the outer grooves 30 of the book.

The adhesive is fixed to the end case member 20 by the groove 30, and the four corner portions are structurally strong and stable by mortise joints, so that a highly rigid filter assembly can be obtained. In addition, since the end case member 20 has a dish-shaped design provided with the groove 30, the filter material 12 is cut or trimmed (zigzag-shaped). Assembly of the core is possible.

Effect of the Invention As described in detail above, according to the present invention, the filter medium applied to the accordion pleats is placed in a sealing engagement over the entire circumference by the surrounding frame, and can be effectively used at normal temperature and high temperature. A highly efficient air filter can be obtained. The pleated filter core is maintained in a sealing engagement with a sealant that is initially liquid but gradually cures to an air-impermeable solid,
As a result, a frame structure of the air filter in which the function of the frame is improved can be obtained.

Also, the present invention does not require the use of additional fasteners or restrainers for maintaining structural stability and integrity. Since the mortise joint is not provided over the entire width of the side and end case members between the upstream and downstream sides of the completed filter assembly, it may be in the adhesive or the adhesive and the case member. Can prevent the formation of a potential leak path in the event of a crack between them.

[Brief description of the drawings]

1 is an exploded perspective view of the components of the filter tree of the present invention, FIG. 2 is a perspective view of one of the side casings of the filter structure of FIG. 1, and FIG. 3 is an end of the filter structure of FIG. FIG. 4 is a front view of the filter structure in an assembled state, FIG. 5 is a side view of the same, FIG.
FIG. 7 is a partially enlarged sectional view taken along line 6-6 in FIG. 7, and FIG. 7 is a partially enlarged sectional view taken along line 7-7 in FIG. 10 Filter core 12 Filter medium 14 Spacer member 16 Frame 18 Side casing 20 End casing 22 Mortise 24 Recess 26 Wall 28 Mortise 30 Groove 32 ... Bottom (groove) 34 ... Top (groove) 36 ... Glue in recess 38 ... Glue in mortise 28 40 ... Glue in groove 30

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Joseph Dourillo United States 13027 New York Baldwindsville Transit Lane (58) Fields studied (Int. Cl. ⁶ , DB name) B01D 46/52

Claims (26)

(57) [Claims] 1. An air filter assembly comprising: a) a plurality of adjacent pleats having zigzag edges on two opposite sides and a flat panel on the other two opposite sides. A filter core comprising a single sheet of air permeable filter media folded in accordion form and a spacer disposed between opposing walls of said continuous pleats; b) said filter media in airtight engagement from four sides A) a box-shaped frame surrounding the assembly to define an airflow opening extending between the upstream and downstream sides of the assembly; i) a pair of frames each having a length L, a width W, and a thickness T; Identical and generally rectangular side casings; ii) formed at both ends of each of said side casings;
A tenon having a length L ', a width W', and a thickness T ', respectively; iii) a pair of identical and generally rectangular end casings having a length l, a width w, and a thickness t; iv) said ends. A recess formed on each main surface of the end casing and inward from the periphery of the end casing, wherein the recess has a generally uniform depth d from the main surface, and each side of the end casing A mortise having a generally uniform depth D 'greater than the depth d from the major surface at each end of the end casing, the mortise bordering a wall comprising the outer edge of the end casing at a portion thereof. V) a plurality of grooves, each opening of which communicates with the recess, wherein the groove has a generally uniform depth D greater than the depth d from the main surface. A plurality of grooves having a bottom, wherein the plurality of grooves communicate with the mortise at both ends thereof; C) an outer surface of the panel-like portion of the air-permeable filter medium is hermetically sealed to an opposing inner surface of the side casing, and the zigzag edge of the filter medium. Is located in the recess, the tenon of the side casing is located in the mortise at both ends of the recess, thereby forming a mortise joint between the side casing and the end casing; d. A) a solid adhesive filled in each of the concave portion, the mortise, and the groove of the end casing, wherein the solid adhesive wraps the zigzag edge and the tenon; The air filter assembly comprising: 2. The air filter assembly according to claim 1, wherein said adhesive is an adhesive mainly composed of sodium silicate having high strength at high temperature. 3. The end casing and the side casing are made of a plate made of calcium silicate.
An air filter assembly according to any of the preceding claims. 4. The air filter assembly according to claim 1, wherein said depth D is at least twice as large as said depth d. 5. The filter assembly of claim 4, wherein said grooves are parallel to each other and to a side edge of said end casing. 6. The air filter assembly according to claim 5, wherein the width of the opening of the groove is smaller than the width of the bottom of the groove. 7. The air filter assembly according to claim 6, wherein said depth D 'is larger than said depth D. 8. The air filter assembly according to claim 7, wherein said length L 'is larger than said depth d and smaller than said depth D. 9. An air filter assembly comprising: a) forming a plurality of adjacent pleats having zigzag edges on two opposite sides and a flat panel on the other two opposite sides. A filter core comprising a single sheet of air permeable filter media folded in accordion form and spacers disposed between opposing walls of the continuous pleats; b) hermetically engaging the filter media from four sides. A box-shaped frame surrounding the assembly and defining an airflow opening extending between an upstream side and a downstream side of the assembly; i) opposing an outer surface of the flat panel-shaped portion; A pair of identical and generally rectangular side casings having an inner surface that hermetically adhesively engages; ii) an end casing having substantially the same width as the side casing, wherein the side casing and the end Are arranged at right angles to each other Iii) a pair of identical and generally rectangular end casings forming a zigzag frame, iii) recesses formed in opposing inner surfaces of the end casings, the recesses being the zigzag edges of the air permeable filter media. And iv) a tenon extending from each end of the side casing into the recess to form a mortise joint between adjacent ends of the side and end casings. The air filter assembly comprising: the box-shaped frame; and c) a solid adhesive filled into at least one of the recesses and completely embedding the zig-zag edge and the tenon. 10. The mortise according to claim 9, wherein the recess has a central portion in which the zigzag edge of the filter medium is entirely disposed, and the tenon is inserted into a tenon at each end of the central portion. Air filter assembly. 11. The mortise is formed deeper than the central portion on the opposed inner surfaces of the end casing.
10. The air filter assembly according to 10. 12. The air filter assembly according to claim 11, wherein said zigzag edge of said filter medium extends to a substantially deepest portion of said central portion of said recess. 13. The air filter assembly of claim 12, wherein said mortise extends into said mortise but does not extend substantially to the deepest portion of said mortise. 14. The end casing further includes at least one groove formed deeper than the recess in each of the opposed inner surfaces of the end casing, the groove communicating with the recess at a side portion and at both ends. 12. The air filter assembly according to claim 11, wherein the air filter assembly communicates with the mortise. 15. The air filter assembly according to claim 14, wherein said mortise extends deeper than said groove in said opposed inner surface of said end casing. 16. The air filter assembly according to claim 15, wherein said groove has a groove having a groove width on one side smaller than that of the other side. 17. The plurality of grooves extend parallel to and spaced from each other on each of the opposing inner surfaces of the end casing and parallel to opposing side edges of the end casing. 16. The air filter assembly according to 16. 18. The air filter assembly according to claim 17, wherein each of said grooves has a constant cross section along the longitudinal direction. 19. A method of manufacturing an air filter assembly, comprising: a) folding a single sheet of air permeable filter media into an accordion shape, with a zigzag edge on the common surface of the two opposing ends and the other end. B) providing a plurality of adjacent pleats, each having a flat panel-like portion on two opposite sides thereof, b) a pair of identical, generally rectangular side casings having a smaller width and thickness than the side casings. And forming said side casing with a tenon extending outwardly from each end of said side casing; c) making a pair of identical and generally rectangular end casings equal to said side casings; Forming the end casing having a width and a recess formed in the main surface of the end casing, the side and the end each having the recess bordering the outer peripheral side wall of the end casing. , D) before The flat panel-like portion is adhesively fixed to the inner side surface of the side casing so as to hermetically engage with the opposite side surface. E) The concave portion of one of the end casings is filled with a flowable adhesive which can be hardened in a solid state. F) arranging the side casing such that one end casing and one end are at an angle of 90 degrees, and a tenon at one end of each of the side casings and one end of the filter medium; G) fully embedding the zigzag edge of the adhesive in the adhesive; g) fully curing the adhesive in the one end casing until it is non-flowing; h) the other end casing. Filling said recess with said liquid adhesive; i) inverting said filter medium, said side casing and one end casing, and said end casing with said other end casing 90 And place them at a degree angle. The tenon at the other end of each of the side casings and the zigzag edge at the other end of the filter media are completely embedded in the adhesive; j) the adhesive in each of the end casings; Curing the air filter assembly into a solid state. 20. The method according to claim 20, further comprising the step of arranging a corrugated spacer member on an opposite side of a continuous pleat of the filter medium before fixing the flat panel portion to the side casing.
20. The method for manufacturing the air filter assembly according to 19. 21. The concave portion of each of the end casings has a central portion formed from the main surface to a predetermined depth, and at each end of the central portion, a depth greater than the predetermined depth over the entire width of the central portion. 21. The air filter assembly of claim 20, further comprising a mortise, wherein the mortise is disposed within the mortise and the zigzag edge of the filter media is disposed at the central portion between the mortises. Production method. 22. At least one side of said recessed portion of said end casing having one side communicating with said central portion and an opposite end communicating with said mortise at an opposite end of said central portion. 22. The method for manufacturing an air filter assembly according to claim 21, further comprising a step of forming one groove. 23. The method of claim 22, wherein the groove has a uniform groove cross section over its entire length. 24. The method of claim 23, wherein said grooves are parallel to opposite side edges of said end casing. 25. The adhesive according to claim 22, wherein said flat panel portion abuts said side casing and extends along at least one side of said assembly along each side of said assembly in a region extending between said end casings. 20. The method for manufacturing an air-filter assembly according to claim 19, further comprising the step of placing a bead-shaped portion. 26. The method according to claim 25, wherein the bead-shaped portion of the adhesive is applied only on the downstream side along each side of the filter assembly.