JPH07144111A - Production of integrally formed filter element - Google Patents

Abstract

PURPOSE:To provide a production method of a filter element without necessitating a sealing work and a fitting work of a can body mounting fitment which require a manpower and a time to set up the element by forming a filter part and a can body mounting part integrally. CONSTITUTION:The filter part and the can body mounting part are first devided, and a bag-like body made of a felt sheet of a high heat resistant polyimide fiber is formed, and the filter part of the bag-like body is edged to plural bag- like cells which are vertically long, opened at a single side and arranged in parallel, and plural permeable bar-shaped or tubular core fins having desired section shape are disposed to the bag-like cell, and a can body mounting fitment is disposed to the can body mounting part of bag-like cell. Then, the integrally formed filter element having self-supportable and rigid parallel-arranged structure obtained by integrating under heating the bag-like body into one body is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter element used in a dust collector for collecting dust from air or other gas (gas) containing dust, and particularly for collecting soot and other fine particles in exhaust gas from an incinerator. It relates to a method of manufacturing a suitable filter element.

[0002]

2. Description of the Related Art As a filter element used in a dust collector, there is a cartridge type filter element which is self-supporting and self-supporting and easy to replace. These filter elements have various shapes, for example, cylindrical shapes and envelope shapes, and in many cases, the filter itself has a corrugated surface to increase the filtration area. As the material of the filter, natural fiber, synthetic fiber, glass fiber or the like is used. The fibers are carded into paper or processed into a non-woven fabric, which is formed into a corrugated shape, and the bellows-shaped filter material is arranged into a cylindrical shape, an envelope shape, or the like, and the ends thereof are made of metal or synthetic resin. A manufacturing method is known in which a cartridge-type element is formed by adhering or pressure-bonding to a frame material (frame) and a can body attachment portion, and sealing.

[0003] Further, by molding a granular polyethylene mold,
A filter element is manufactured by arranging a corrugated filter material formed into a corrugated shape into an envelope shape, and further filling a filler made of polytetrafluoroethylene in the air bubbles between the granular polyethylenes and adjusting the filtration pore size. How to do it is fair 2-
It is described in Japanese Patent Publication No. 39926. When a filter material is molded from a granular material using a mold as described above, it is necessary to manufacture a precise mold, which is expensive, and in the above-described filter material manufacturing, a molded product that has been once molded by the mold is used. Since it requires a step of filling with a filler, the manufacturing cost is higher and the manufacturing time is long.
Further, since it has a polyethylene molded body as a skeleton, it cannot withstand a temperature of 100 ° C. and cannot be said to be a heat resistant filter element.

Aromatic polyimide is a raw material polymer having excellent properties such as excellent thermal stability and flame retardancy. However, this aromatic polyimide is difficult to melt without decomposition, and because it is soluble only in a polar solvent having a high boiling point, for example, in the case of film formation, a usual melt film formation method or solution film formation The method is difficult to use. Therefore, when a molded body is molded using a polyimide powder material such as granular polyethylene in the case of manufacturing the filter element described in JP-B-2-39926, it is necessary to process it into a pre-molded body. As described above, molding of a molded body is not easy.

A non-woven fabric or felt sheet made of high heat-resistant polyimide fiber is used as a starting raw material, and a non-woven fabric or felt sheet made of high heat-resistant polyimide fiber is heated at a temperature exceeding the glass transition point of polyimide for an appropriate period of time to give an aroma. Japanese Patent Application Laid-Open No. 2-503333 discloses a method for molding a breathable molded article by the mutual fusion of the shrinkage of the group-polyimide fibers and the promotion of the fibers. Although it is possible to mold a simple molded product such as a flat plate shape or a cylindrical shape using this technique, it is difficult to manufacture a filter having a surface corrugation that can stand on its own. Further, since the method for producing the breathable molded product uses a mold, a great deal of labor is required to attach the nonwoven fabric or the felt, and further, it takes a long time for heating, heating and cooling, which results in a production cost. Becomes higher.

The present inventors have conducted research to manufacture a high heat resistant filter, and after forming a felt sheet or a nonwoven fabric (hereinafter simply referred to as felt sheet) of high heat resistant polyimide fiber, preheating the felt sheet, After forming the corrugated corrugated product through each step of molding and cooling, cut the corrugated corrugated molded product to the required size, fix two by facing this with a support frame, leave one side and leave a gap between the molded products. A box-shaped filter element was manufactured by sealingly adhering, and a method for attaching a can body mounting bracket to this element was completed.

Further, as shown in FIG. 15, two felt sheets 5 made of high heat resistant polyimide fiber are superposed,
As shown in FIG. 16, two felt sheets 5 are sewn in a line shape, and are edged into a plurality of vertically elongated bag-shaped cells 10 each having one open side. As shown in FIG. 1 has a tubular core 19 having a desired cross-sectional shape, and is internally supported and then heat-shrinked, or FIG.
As shown in 8, after being sandwiched between metal molds 20 and subjected to heat compression molding, the fitted tubular core 19 is pulled out to produce a filter element, and the filter element is brought into close contact with the outside of the open end portion thereof, A method for manufacturing an external filter element 22 shown in FIG. 19 is completed by sandwiching a pair of upper and lower can body mounting members 21 and heating or welding the can body mounting members 21. (Japanese Patent Application No. 5-170
(974)

[0008]

However, the previously proposed method for manufacturing a filter element for manufacturing the above-mentioned box-shaped filter element or a filter element to which a can body mounting member is externally attached has the following problems. Have. That is, (1) a great deal of labor and time are required for the sealing operation for sealing the gap between the molded products when assembling the filter element, or for the sealing work required when mounting the can body mounting member on the element. (2) In the sealing work, individual differences occur among workers, resulting in uneven quality of the filter element. (3) Mechanization of the sealing work is not impossible, but it requires a great deal of cost. (4) Although pinholes are generated by adhesion, it is difficult to confirm and inspect these pinhole failures. (5) The sealing operation requires elastic and expensive heat-resistant adhesive or heat-resistant sealant. (6) After the heat compression molding, the work of pulling out the fitted tubular core is a difficult work and takes time. It is such a problem.

The object of the present invention is to solve the problems of the previously proposed method of manufacturing the filter element, and to perform a sealing work required for assembly and a work requiring a lot of labor and time such as mounting a can body mounting member. It is an object of the present invention to provide a method of manufacturing a filter element in which a filtration portion and a can body mounting portion are integrally molded by heating, which does not require.

[0010]

The above object is achieved by the method for manufacturing an integrally molded filter element according to the present invention. That is, the method for producing the integrally molded filter element, which is the object of the present invention, comprises: 1) a felt sheet 2 made of highly heat-resistant polyimide fiber.
The two sheets are piled up, and the two felt sheets are edged in a bag shape with one side open, and a plurality of vertically elongated one side open bag cells are arranged in a parallel arrangement, leaving a blank part for mounting fittings. After inserting a breathable rod-shaped or tubular core made of a heat-resistant rigid material having a desired cross-sectional shape from the open end into the bag-shaped cell for internal support, and then inserting a mounting member in the blank portion. , A self-supporting rigid parallel array structure having a plurality of protruding cells, characterized in that the open end of the bag-like felt sheet is fixed to the inlet of the fitting, and the filter and the fitting are integrally molded by heating. A method of manufacturing an integrally formed filter element having

Or 2) The breathable rod-shaped or tubular core is inserted into the plurality of bag-shaped cells of one-sided bag-shaped body composed of two felt sheets of the high heat-resistant polyimide fiber, and the blank portion is inserted. After fitting the mounting member into the inside, when fixing the open end of the bag-shaped felt sheet to the inlet portion of the mounting member, the open end of the bag-shaped felt sheet is sealed with a homogenous felt sheet piece by stitching or heat bonding. It is achieved by the method for producing an integrally molded filter element having a self-supportingly rigid parallel array structure according to 1), which is characterized by stopping and fixing.

The steps of edging the two felt sheets as a whole into one open bag shape and the step of edging into a plurality of vertically-oriented one-side open bag-shaped cells in a parallel arrangement leaving a blank portion in which a mounting fitting is inserted. The steps may be performed simultaneously, or as a separate step, the steps may be performed in two steps. Examples of the heat-resistant rigid body material include metal materials, heat-resistant resin materials, and ceramic materials. Examples of the air-permeable tubular or rod-shaped core include hollow perforated tubular cores, porous tubular cores or rod-shaped cores made of fiber aggregate. Therefore, if a breathable rod-shaped or tubular core made of a heat-resistant rigid material is more specifically shown, a punching metal tubular core, a carbon fiber aggregate rod-shaped core, or the like can be exemplified.

A method of fixing the open end of the felt sheet bag to the inlet portion of the mounting member after fitting the mounting member into the blank portion of the felt sheet bag will be described with reference to FIG. Various methods such as folding the felt sheet 5 and fixing it by using a metal flat plate 15 and a fastener 16 as shown in FIG. 10 can be adopted. However, as will be described later in detail using an example, the open end of the bag-like felt sheet is sealed with a homogenous felt sheet piece by stitching or thermal bonding on the outside of the fitting fitting inlet portion, and then heat-molded and fixed. The method is preferable because it does not require a special jig and can be tightly fixed.

In the case of edging the felt sheet in a bag shape and further edging in a plurality of vertically elongated one-sided open bag-shaped cells in parallel arrangement, the edging method may be stitching or heat bonding in a line shape. . Further, in a plurality of vertically-oriented one-side open bag-shaped cells of a parallel array bordered on the bag-shaped felt sheet, the rod-shaped core is inserted from the open end, as the cross-sectional shape of the rod-shaped core to be inserted, Various cross-sectional shapes such as a rhombus, a circle, an ellipse, a rectangle, and a polygon can be mentioned. In the previously proposed method for manufacturing the filter element, the metal tubular core 19 fitted into each bag-shaped cell from the open end is pulled out after molding, but a hollow core such as a hollow perforated core is used. In this case, even if the filter element is completed while remaining in the filter element, quality problems such as filtration characteristics of the filter do not occur.

The highly heat-resistant polyimide fiber used in the present invention can be any polyimide fiber having a heat resistance of at least 280 ° C. and capable of achieving the object of the present invention. A preferred example is a fiber made of a polyimide having a repeating unit represented by the general formula (1).

[0016]

[Chemical 1]

A method for obtaining a structure-free fleece from the polyimide fiber used in the present invention is described in US Pat. No. 4,188,690. A method for producing felt from this fleece is described in West German Patent 1,785,165.
Further, the sheet made of the high heat-resistant polyimide fiber used in the present invention may be not only a felt sheet but also a sheet made of non-woven fabric.

The method for manufacturing the integrated filter element of the present invention will be specifically described below with reference to FIGS. However, the following description is for deepening the understanding of the present invention and does not limit the invention.

(Description of Specific Manufacturing Method) Felt sheet 5 made of high heat-resistant polyimide fiber shown in FIG.
Are sewn into a bag shape, leaving one end thereof, for example, by sewing, and then a plurality of vertically long one-side open bag-shaped cells arranged in parallel are left, leaving a portion forming a tubular portion and a bag margin portion 7 as shown in FIG. The edging 10 is performed, for example, by sewing. Then, the blank portion on the opposite side of the bag blank portion 7 is rolled to form the tubular portion 6.
(FIG. 4) FIG. 5 illustrates a hollow perforated core 4 and a mounting member 2 used for manufacturing the integral filter element of the present invention. The hollow cored core 4 illustrated is a tubular core made of punching metal having a rhombic cross-section, but as described above, the cross-sectional shape may be rhombic, round, elliptical, rectangular or polygonal. good. Further, in order to make the core 4 air-permeable, a rod-shaped core made of another fiber assembly having a hollow perforated tubular structure, a porous tubular core, or the like may be used. If the punching metal has a thickness of 0.3 mm, it may not be able to withstand the pressure during processing.
The thickness is preferably m or more, and 0.5 mm is particularly preferable.

The mounting member 2 shown in FIG. 5 is a mounting member for mounting the filter element of the present invention on the can body of the dust collector, and is not particularly limited as long as it is made of a material having high heat resistance and rigidity. However, it is usually made of metal.
The recesses on both side surfaces of the mounting member 2 are necessary for positioning when fixed to the can body. The opening 9 is an opening for discharging the dust-removed gas. FIG. 6 shows a state in which, for example, a metal cylindrical rod 18 is inserted into the tubular portion 6 of the bag-shaped felt sheet formed by sewing, for example, as shown in FIG. Inserting the cylindrical rod 18 into the tubular portion 6 is not an essential step in the production of the integral filter element of the present invention, but the end of the end portion of the element opposite to the fitting 2 of the element when it is thermoformed. It prevents excessive shrinkage and the tubular part 6 later serves as a cushioning material during the use of the filter element. Therefore, as long as it is a component having such an action, it is not necessary to insert the cylindrical rod 18 into the tubular portion 6, and for example, a thick metal plate may be passed through the tubular portion 6 to prevent various types of shrinkage. A method can be considered.

For example, a rod-shaped core 4 made of punching metal having a rhombic cross section shown in FIG. 5 is inserted into the bag-shaped cell 10 of the formed bag-shaped felt sheet shown in FIG. The mounting member 2 made of, for example, metal shown in FIG. FIG. 7 is a view of this state viewed from the open end side of the bag-like felt sheet. As shown in FIG. 7, the rod-shaped core 4 inserted into the bag-shaped cell 10 through the mounting member 2 can be seen. In this state, for example, a felt sheet of the same quality is applied to the opening of the bag-shaped felt sheet, and the both are sewn together to seal the opening. Further, in this state, as shown in FIG. 9, the holding metal fitting 1 is attached to the elbow portion of the mounting member 2.
2, the bolt 13 is passed through the concave portion of the mounting member 2, and the nut 14 is tightened to complete the pre-preparation state of the integrally molded filter element of the present invention as shown in FIG. 8 before thermoforming.

To the filter element in the ready state shown in FIG. 8, for example, metal flat plates are placed on the upper and lower surfaces of the element, and the metal flat plate 15 is pressed down by the metal fittings 16 at its main portions, and placed on the frame in the thermoforming chamber. , Supports the cylindrical rod 18 appropriately. (FIG. 10) In the state of FIG. 10, the temperature of the heating molding chamber is raised to raise the temperature of the filter element in the ready state to 250 to 430 ° C.
Shrink molding is performed by heating to an appropriate temperature within the range. The time required for heating / shrink molding is usually 10 minutes to 2 hours, but heating / shrink molding may be performed for a time determined by the characteristics such as air permeability of the filter element, and is not particularly limited.

Thus, the metal flat plate 15 and the press fitting 12
The cylindrical rod 18 is removed to complete the outer shape of the integrally molded filter element 1 of the present invention shown in FIG. FIG. 2 shows a deployed state of the attachment member 2 and the hollow perforated core 4 in the integrally molded filter element 1 of the present invention in this state. The breathable film (felt sheet 5) on the upper end of the attachment member 2 of the filter element 1 shown in FIG.
Is a breathable film obtained by heating and shrink molding. 11) is cut out as shown in FIG. 11 to form the opening 9 to complete the integrally molded filter element 1 of the present invention.
Here, the shape of the opening 9 formed by cutting out the breathable film on the upper end portion of the attachment member 2 of the filter element 1 may be a single elongated elliptical shape as shown in FIG. There is no particular limitation as long as the dust-excluded gas can be passed without resistance, such as openings in which square openings are arranged in a line.

FIG. 12 shows a front view of the integrally molded filter element 1 of the present invention, and FIG. 14 shows a side view thereof. Further, FIG. 13 is a schematic view showing a cross-sectional shape of the filtering portion of the integrally molded filter element 1 of the present invention. However, this schematic cross-sectional view is one example in the description of this specific embodiment, and as described above, the cross-sectional shape is a rhombus, a round shape, an oval shape,
It may have various sectional shapes such as a rectangle or a polygon.

[0025]

EXAMPLE An example of a method for producing an integrally molded filter element composed of the air-permeable, highly heat-resistant polyimide molded body of the present invention will be described below with reference to Examples. However, the present invention is not limited to the examples below.

Example 1 80 g of benzophenone-3,3 ', 4,4 was previously added to a container.
500 g of a basis weight preformed from a polyimide fiber having a draw ratio of 1: 5 and a thickness of 30 μm prepared from ′ -tetracarboxylic dianhydride and 4,4′-methylene-bis- (tolylene isocyanate) by a needle punch method. / M ² , felt sheet 2.2 mm thick, width 3,500 m
A test piece having a length of m and a length of 1,500 mm was cut out. The chemical structural formula of the polyimide constituting the above polyimide fiber is shown below.

[0027]

[Chemical 2]

Two test pieces are superposed and sewn together
A sewn area around each of three felt sheets is sewn together, and a blank space of 350 mm for inserting a mounting member and a blank space of 100 mm for providing a cylindrical portion for inserting a cylindrical rod.
The center width is 3,500 mm and the length is 1,050 m
Width 70mm, length 1,050mm by sewing on m part
50 bag-shaped cells were produced in parallel so as to have an open end on the open side of the original felt sheet bag, and these bag-shaped cells had a rhombic cross-section with a diagonal length of 50 mm × 20 mm, A punching metal rod-shaped core having a length of 1,000 mm and a thickness of 0.5 mm is inserted. The punching metal rod-shaped core made of punching metal has four holes with a diameter of 3 mm.
They are provided with a pitch of mm and the open area ratio is 51%.

Furthermore, a metal mounting member having a width of 1080 mm, a thickness side having an opening and a recess of 62 mm and a height of 55 mm is provided in the bag margin portion above the bag-shaped cell into which the rod-shaped core is inserted (the thickness side thereof). (With the open side of the bag), and the open part of the felt sheet bag is sewn and sealed with a felt sheet of the same quality as the felt sheet and similar in size to the thickness side surface of the attachment member. By enclosing the metal mounting member in the bag margin, the pressing metal fitting shown in FIG. 9 is applied to the elbow portion of the mounting portion generated in the bag, and the notch of the pressing metal fitting and the concave portion of the mounting material are applied. Thread the bolt (over the felt sheet covered with the felt sheet), tighten with the nut, and shape the mount as shown in FIG.

First, in the description of the concrete manufacturing method of the present invention,
As shown in FIG. 10, a metal flat plate is placed on both upper and lower surfaces of the filter element that has been shaped in the ready state, and the metal flat plate is held down by the metal fittings at its main part, and placed on the pedestal in the thermoforming chamber, and the cylindrical rod is attached. It is placed in a thermoforming chamber while being properly supported, the temperature inside the thermoforming chamber is raised, and the temperature of the ready-state filter element is heated to 330 ° C. to perform shrink molding for 1 hour. The temperature of the heat molding chamber is cooled to room temperature, the metal flat plate and the pressing metal fitting are removed, and the cylindrical rod is pulled out from the tubular portion. Subsequently, in the portion corresponding to the opening of the attachment member, 18 circular openings having a diameter of 30 mmφ are provided at a pitch of 50 mm to form a breathable sheet made of polyimide to form the ventilation opening. Thus, a filter element having 50 protruding cells and having a filtration area of about 6 m ^{2 and} an integrated attachment portion is completed. The ventilation opening of the filter element may be a slit-shaped opening having a width of 50 mm and a length of about 1000 mm.

[0031]

【The invention's effect】

(1) In the integrally formed filter element of the present invention, the constituent members are inserted into a bag made of a raw material felt sheet, the whole is wrapped with the felt sheet, and the felt sheet is heat-shrinked, so that the filtration portion and the attachment portion are provided. Since it is molded as one piece, it is easy to assemble and it is possible to stably manufacture a good quality element. (2) In the integrally molded filter element of the present invention, there is no concern that seal leakage will occur between element members. (3) The step of assembling the filtration unit and other members unlike the box-shaped filter element is unnecessary. (4) It is not necessary to bond and seal the gap between the molded products as in the case of the box-shaped filter element or the filter element to which the mounting member is externally attached. (5) Since it is not necessary to seal the gap between the molded products,
No sealing material or sealant is required. (6) The step of pulling out the core of the filtration section and the device therefor are unnecessary. (7) When the upper seal of the attachment member is sewn with a breathable felt sheet of the same quality for sealing, the sealing surface is flat, and this portion can be cut to easily form an opening. (8) When the mounting portion is sealed by the sealing method of (7), since the sealing surface is flat, the surface of the mounting member of the dust remover and the filter element mounting member are The surface can be tightly sealed with a gasket, and the leakage of dust can be prevented.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of an integrally molded filter element of the present invention.

FIG. 2 is an explanatory view showing the constitution of an example of the integrally molded filter element of the present invention.

FIG. 3 is a perspective view showing a state where a felt sheet, which is a raw material of the filter element of the present invention, is sewn.

FIG. 4 is a perspective view showing a state in which a tubular portion is formed on the sewn felt sheet of FIG.

FIG. 5 is an explanatory view showing constituent members of the integrally molded filter element of the present invention.

FIG. 6 is an explanatory view showing an intermediate step of manufacturing the filter element of the present invention.

FIG. 7 is an explanatory view showing an intermediate assembly step of manufacturing the filter element of the present invention.

FIG. 8 is a perspective view showing an assembled state of the integrally molded filter element of the present invention before heat molding.

FIG. 9 is a perspective view showing a state of curing before heat molding in the vicinity of a mounting portion of the integrally molded filter element of the present invention.

FIG. 10 is a perspective view showing a curing state of the entire integrally-formed filter element of the present invention before heating and molding.

FIG. 11 is a view of the integrally formed filter element of the present invention as seen from the exhaust port side.

FIG. 12 is a front view of the integrally molded filter element of the present invention.

FIG. 13 is a schematic cross-sectional view of a filtration portion of the integrally molded filter element of the present invention.

FIG. 14 is a side view of the integrally formed filter element of the present invention.

FIG. 15 is a perspective view showing a state in which raw material felt sheets of the attachment member outer type filter element are stacked.

16 is a perspective view showing a state in which the raw material felt sheets of FIG. 15 are sewn together.

FIG. 17 is a perspective view showing a state in which a core is inserted into a bag-shaped cell in manufacturing the mounting member outer type filter element.

FIG. 18 is an explanatory view showing a manufacturing process of heating / pressurizing the mounting member outer filter element.

FIG. 19 is an explanatory view showing a step of attaching the attachment member in the production of the attachment member external type filter element.

FIG. 20 is a perspective view showing an attachment member external filter element.

[Explanation of symbols]

 1 integrally formed filter element 2 of the present invention 2 attachment member 3 seam 4 hollow core 5 felt sheet 6 tubular portion 7 bag margin portion 8 attachment portion 9 attachment member opening portion 10 bag-shaped cell 11 filtration portion 12 presser metal fitting 13 Bolts 14 Nuts 15 Flat plates 16 Clamps 17 Stands 18 Cylindrical rods 19 Tubular cores 20 Metal molds 21 External mounting members 22 Mounting members External filter elements

Claims (2)

[Claims] 1. Felt sheets made of high heat resistant polyimide fibers are superposed on each other, and the two felt sheets are edged in a bag shape with one side open, and a parallel arrangement is made, leaving a blank part into which a fitting is inserted. Edged into a plurality of vertically long one-side open bag-shaped cells, insert a breathable rod-shaped or tubular core made of heat-resistant rigid material having a desired cross-sectional shape from the open end into the plurality of bag-shaped cells After supporting and then fitting the mounting member into the margin, the open end of the bag-like felt sheet is fixed to the inlet of the mounting metal fitting, and the filtration part and the mounting part are integrally molded by heating. A method for manufacturing an integrally molded filter element having a rigid parallel array structure. 2. The breathable rod-shaped or tubular core is inserted into the plurality of bag-shaped cells of one-sided bag-shaped body composed of two felt sheets of the high heat-resistant polyimide fiber, and the inside of the blank portion is inserted. After fitting the mounting member into the mounting member, the opening end of the bag-shaped felt sheet is fixed in fixing the opening end of the bag-shaped felt sheet to the mounting member inlet portion.
The method for producing an integrally molded filter element having a rigid parallel array structure capable of self-sustaining according to claim 1, wherein the felt sheet pieces of the same quality are sealed and fixed by stitching or heat bonding.