Manhole Interrupting Devic Of Sewage and Stench Countercurrent

Abstract

The present invention relates to a sewage and odor backflow blocking device for a manhole that is installed at the bottom of a grating installed at the top of a manhole or sewage collection outlet, so that rainwater is drained smoothly during rain and odors or sewage backflow are prevented. The device is composed of a body located at the bottom of a grating installed in a manhole and fixed by being pressed by the weight of the grating, and a drainage hole blocking device having a size larger than the size of the drainage hole that blocks or opens the drainage hole.

Description

Technology Field

[0001] The present invention relates to a sewage and odor backflow blocking device for a manhole, which is installed at the bottom of a grating installed at the top of a manhole or wastewater collection outlet to smoothly drain rainwater during rain and prevent backflow of odors or wastewater. Background Technology

[0003] Generally, a manhole is connected to a drainage channel or sewer to drain rainwater or sewage, and a grating is installed on top of the manhole to prevent various types of debris from entering along with the rainwater.

[0004] However, the above grating can drain rainwater or sewage and filter out large debris on the ground, but it cannot prevent odors or sewage backflow from the manhole.

[0005] Therefore, in order to resolve the above-mentioned problems, a "manhole odor blocking device" of Korean Registered Patent No. 10-2354746 (Patent Document 1), as shown in Fig. 1, has recently been provided, and its configuration is as follows.

[0006] - under -

[0007] A grating (30) having at least one through hole (31) formed therein for rainwater to flow in, which is combined with a manhole (20), and

[0008] A plate-shaped main body (62) having a plate-shaped upper surface formed in a flat shape so as to be in close contact with the lower surface of the grating (30) and a plurality of inlets (61) formed therein,

[0009] Blocking doors (67) that open and close the inlets, with a hinge shaft (66) rotatably installed on the lower surface of the main body (62), and

[0010] A weight member (68) installed on each of the above-mentioned blocking doors (67) and pressing the blocking doors (67) against the main body in a closing direction due to their own weight, and

[0011] It includes an auxiliary weight member (68a) capable of controlling the rotational force for blocking the inlet by the above-mentioned blocking door,

[0012] A blocking unit (60) having a lip (68) that is in close contact with the main body part (62) at the edge of the blocking door (67) to increase the sealing force, and

[0013] A coupling unit (100) is provided to combine the above grating (30) and the main body (62) of the above blocking unit (60) so that the main body (62) is in close contact with the lower surface of the grating (30).

[0014] The above coupling unit (100) comprises a locking member (101) supported on the rib of the grating (30), and a coupling member (104) supported on each locking member (101) and screw-coupled to a fixing part (103) formed by insert-molding a nut into the main body part (62).

[0015] The surface of the main body (62) or the blocking door (67) corresponding to the through hole (31) of the grating (30) is formed with a protrusion that prevents debris from adhering to the surface of the main body (62) or the blocking door (67) when the vacuum suction force of the cleaning vehicle is applied.

[0016] The conventional "manhole odor blocking device" with the above configuration has a complex structure, and the operation of the blocking door (67) is not smooth, and the blocking of odors generated from the manhole does not meet expectations. Prior art literature

[0018] Republic of Korea Registered Patent 10-2354746 (Publication Date: Jan. 24, 2022) Republic of Korea Registered Patent 10-1266114 (Publication Date: May 27, 2013) The problem to be solved

[0019] The present invention was invented to resolve the above-mentioned problems, and its purpose is,

[0020] First, rainwater drains smoothly into the grating installed above the manhole or sewage collection channel, and prevents the backflow of odors, and

[0021] Second, since it is not damaged or broken by high loads or impacts, the vehicle can be driven or parked freely, and

[0022] Third, the invention provides a sewage and odor backflow blocking device for manholes capable of sterilizing harmful bacteria generated in manholes or sewage collection outlets. means of solving the problem

[0023] The configuration of the means for solving the problem of the present invention for achieving the above objective comprises: a plurality of drainage holes (120) formed at regular intervals along the length or width direction of a flat cover (110) located at the bottom of a grating installed in a manhole and fixed by being pressed by the weight of the grating; pin fixing members (130) formed at both ends of each drainage hole on the back surface of the cover, wherein each pin fixing member on one side has a pin hole (131) formed to rotatably insert a fixing pin (250), and each pin fixing member on the other side has mutually facing elastic pieces (132a), and a rotation hole (132b) formed on the inner side of the elastic pieces to rotatably seat the fixing pin, and mutually facing protrusions (132c) formed on the lower two elastic pieces of the rotation holes to prevent the fixing pin from detaching, and a lock hole (132) formed from the protrusions to the bottom, wherein a heavy object entry opening (132d) is formed in which the spacing between the elastic pieces gradually increases. A body (100) is provided with a seating ledge (140) formed on the edge of each drain hole on the back side of the cover, on which the outer edge of the damper is seated, and a damper (210) having a size larger than the size of the drain hole that blocks or opens each drain hole is provided, and a pocket (230) is formed such that a weight (220) in the shape of a round bar (221) is seated and fixed in the longitudinal direction of one side of the damper, with one end in the longitudinal direction closed and the other end open, and a weight-holding member (231) is formed in multiple places along the open longitudinal direction to hold the weight, and a rotational inducer (240) that is heavier than the weight of the damper and lighter than the weight of the water filling the drain hole between the cover and the grating is formed to descend in a continuous manner with the damper, and a fixing pin (250) that is rotatably fitted and installed in the pin fixing member is formed on both ends of the damper on the side where the rotational inducer is formed, and the outer edge of the damper excluding the side where the rotational inducer is formed A sealing portion (260) is formed on the surface and coupled to the above-mentioned seating ledge to maintain the airtightness of the above-mentioned drainage hole, and between the rear surface of the damper and the rotation inducer,A drain hole blocker (200) having a plurality of reinforcing ribs (211) formed at regular intervals to improve the durability of the damper, and the cover (110) and damper (210) comprise 100 parts by weight of one synthetic resin selected from vinyl chloride, polyethylene, polystyrene, polyester, polypropylene, and polycarbonate; 3.5 to 6.5 parts by weight of a stabilizer selected from one or two types selected from Ba-Zn (barium-zinc) system, Ca-Zn (calcium-zinc) system, triazole system, benzophenone system, and HALS system; and 5 to 10 parts by weight of an MBS (methacrylate butadiene styrene) system, CPE (chlorinated polyethylene) system, or ABS (acrylonitrile butadiene styreneterpolymer) system impact reinforcing agent. 2 to 10 parts by weight of maifan stone powder with a particle size of 1000 mesh or larger and coated with stearic acid; 0.5 to 1.5 parts by weight of a processing aid obtained by emulsion polymerization of an acrylate-based monomer; and 100 to 125 ppm by weight of silver nanopowder with a particle size of 21 to 500 nm; wherein the maifan stone powder is prepared by mixing 100 parts by weight of maifan stone powder with 2 parts by weight of stearic acid, stirring at room temperature up to 65 to 70°C for 10 minutes, and then cooling for 15 to 25 minutes.

[0024] delete

[0025] delete

[0026] delete Effects of the invention

[0027] The sewage and odor backflow blocking device of the present invention, configured as described above, allows rainwater to be smoothly drained into the grating installed above the manhole or sewage collection outlet as explained in the purpose above, blocks the backflow of odors, and enables the free driving or parking of vehicles by preventing damage or destruction due to high loads or impacts, and has the effect of sterilizing harmful bacteria generated in the manhole or sewage collection outlet. Brief explanation of the drawing

[0029] Exploded perspective view of a conventional manhole odor blocking device of FIG. 1, FIG. 2 is an exploded perspective view of a part of the sewage and odor backflow blocking device of the present invention. FIG. 3 is a plan perspective view of the sewage and odor backflow blocking device of the present invention. FIG. 4 is a bottom perspective view of the sewage and odor backflow blocking device of the present invention. FIG. 5 is a cross-sectional configuration diagram of the sewage and odor backflow blocking device of the present invention. FIG. 6 is a perspective view of a rock hole excerpt in the sewage and odor backflow blocking device of the present invention. FIGS. 7A and 7B are cross-sectional views showing the sewage and odor backflow blocking device of the present invention installed in a manhole and operating. Specific details for implementing the invention

[0030] The present invention relates to a sewage and odor backflow blocking device for a manhole, which is installed at the bottom of a grating installed at the top of a manhole or wastewater collection outlet to ensure smooth drainage of rainwater during rain and to prevent backflow of odors or wastewater. An embodiment thereof is described below with reference to the attached drawings.

[0031] The sewage and odor backflow blocking device for a manhole according to the present invention comprises, as shown in FIGS. 2 to 7b, a flat cover (110) located at the bottom of a grating installed in a manhole and fixed by being pressed by the weight of the grating, having a plurality of drainage holes (120) formed at regular intervals along the length or width direction, and a pin fixing member (130) formed on one side of each end of each drainage hole on the back surface of the cover, wherein each pin fixing member on one side has a pin hole (131) formed to rotatably insert a fixing pin (250), and each pin fixing member on the other side has a lock hole (132) formed to rotatably insert and detachably insert the fixing pin, and a seating ledge (140) formed on the edge of each drainage hole on the back surface of the cover to rest the outer edge of a damper, and a damper (210) having a size larger than the size of the drainage hole that blocks or opens each drainage hole is provided, and A damper is configured with a drain hole blocker (200) having a pocket (230) formed in a lengthwise direction such that a weight (220) in the shape of a round bar (221) is fixedly seated in a pocket (230) with a weight-holding member (231) formed in multiple places along the open lengthwise direction to hold the weight, a rotational inducer (240) that is heavier than the weight of the damper and lighter than the weight of the water filling the drain hole between the cover and the grating is formed to descend in a continuous manner with the damper, a fixing pin (250) that is rotatably fitted and installed in the pin fixing member is formed on both ends of the damper on the side where the rotational inducer is formed, and an airtightness maintaining member (260) that is coupled to the seated ledge and maintains the airtightness of the drain hole is formed on the outer surface of the damper excluding the side where the rotational inducer is formed.

[0032] delete

[0033] In the above configuration, the cover (110) forming the body (100) is formed with a flat upper surface and the four outer lower ends of the grating (G) are placed on the edge of the flat upper surface and fixed by being pressed by the weight of the grating (G), and the location where the body (100) and the grating (G) are installed is a manhole or a sewage collection port.

[0034] Additionally, a plurality of drainage holes (120) formed along the length or width direction of the cover (110) drain rainwater or wastewater flowing into the drainage holes (H) of the grating (G), and it is preferable that the direction of the drainage holes (120) be formed in the same direction as the direction of the drainage holes (H) of the grating (G).

[0035] And on the back side of the cover (110), each pin fixing member (130) is formed at one end of each drainage hole (120). Among the pin fixing members (130), each pin fixing member on one side has a pin hole (131) formed so that a fixing pin (250), described below, is rotatably inserted and installed, and each pin fixing member on the other side has a lock hole (132) formed so that the fixing pin (250) is detachably coupled and rotatably inserted and installed. Thus, the fixing pin (250) on one side is inserted and fixed into the pin hole (131), and the fixing pin (250) on the other side is inserted and fixed into the lock hole (132).

[0036] Meanwhile, in one embodiment of the lock hole (132), mutually facing elastic pieces (132a) are formed on the cover (110), and on the inner side of each elastic piece (132a), a rotation hole (132b) is formed facing each other so that the fixing pin (250) can be rotatably seated, and on the lower two elastic pieces (132a) of the rotation hole (132b), a protrusion (132c) is formed facing each other to prevent the fixing pin (250) from coming off.

[0037] From the above protrusion (132c) to the bottom, a weight entry opening (132d) is formed in which the spacing of the elastic piece (132a) gradually widens, and the fixing pin (250) is seated in the rotation hole (132b) through the weight entry opening (132d) and the protrusion (132c), and the fixing pin (250) seated in the rotation hole (132b) is not dislodged by the protrusion (132c) and rotates within the rotation hole (132b) according to the rotation direction of the damper (210).

[0038] The reason the above-mentioned heavy object entry port (132d) is spaced further apart from the protrusion (132c) to the bottom of the elastic piece (132a) is to allow the fixing pin (250) to be easily seated in the rotation hole (132b).

[0039] In addition, a seating ledge (140) is formed on the edge of each drainage hole (120) on the back side of the cover (110) so that the outer edge of the damper (210) is seated thereon and combined with the airtight sealing part (260) formed on the damper (210), thereby maintaining airtightness between the seating ledge (140) and the airtight sealing part (260), so as to block the backflow of odors as well as the backflow of wastewater.

[0040] Preferably, the shape of the above-mentioned airtight sealing part (260) is formed in the shape of a connecting jaw that is closely coupled with the seating jaw (140).

[0041] In addition, the damper (210) forming the drain hole blocker (200) of the present invention is formed with a size larger than the size of the drain hole (120) that blocks or opens each drain hole (120). If the force pressing the damper (210) is greater than the rotational inducer (240), the damper (210) rotates and the drain hole (120) opens, and if the force pressing the damper (210) is less than the rotational inducer (240), the damper (210) does not rotate and the drain hole (120) remains in a blocked state.

[0042] Pressurizing the above damper (210) means that rainwater flows into the drainage hole (H) formed in the grating (G), and the rainwater flowing into the drainage hole (H) pressurizes the damper (210).

[0043] In addition, a heavy object (220) is installed along the longitudinal direction of one side of the damper (210). The reason for installing the heavy object (220) is that when the damper (210) is not being pressed, the damper (210) blocks the drainage hole (120) due to the weight of the heavy object (220). However, when rainwater flows into the drainage hole (H) formed in the grating (G) and the weight of the flowing rainwater becomes heavier than the weight of the heavy object (220), the damper (210) rotates to open the drainage hole (120) that was blocking it, thereby draining the rainwater flowing into the drainage hole (H) of the grating (G).

[0044] A heavy object (220) having the above-mentioned function is fixed in a pocket (230) formed in a rotational inducer (240), and a fixing pin (250) is formed at both ends of the damper (210) on the side where the rotational inducer (240) is formed, which is rotatably fitted into the pin fixing member (130), so that the damper (210) rotates around the fixing pin (250) as an axis.

[0045] In addition, on the outer surface excluding the side where the rotation guide (240) of the damper (210) is formed, a sealing part (260) is formed that is coupled to the seating ledge (140) to maintain the airtightness of the drainage hole (120).

[0046] The function and structure of the above-mentioned confidentiality unit (260) have been explained above, so a redundant explanation thereof is omitted.

[0047] Meanwhile, the pocket (230) has one end in the longitudinal direction sealed and the other end open so that the heavy object (220) is seated and fixed, and a plurality of weight-holding parts (231) are formed in the open longitudinal direction to hold the heavy object (220) so that the heavy object (220) does not move out of the pocket (230).

[0048] Additionally, the above-mentioned weight (220) is preferably formed in the shape of a round bar (221) having a length equal to the length of the pocket (230) so as to be fitted and coupled into a weight-holding member (231) formed along the longitudinal direction of the pocket (230), but it may also be formed and used as a square bar if necessary.

[0049] And the weight of the rotary inducer (240) on which the above-mentioned heavy object (220) is installed is heavier than the weight of the damper (210) and lighter than the weight of the water that fills the drain hole (H) between the cover (110) and the grating (G), so that when rainwater is received in the drain hole (H), the damper (210) rotates due to the weight of the received rainwater and opens the drain hole (120).

[0050] In addition, between the back surface of the damper (210) and the rotation guide (240), a plurality of reinforcing ribs (211) are formed at regular intervals to improve the durability of the damper (210) and prevent deformation of the damper (210).

[0051] The cover (110) and damper (210) forming the sewage and odor backflow blocking device of the manhole according to the present invention as described above,

[0052] 100 parts by weight of one synthetic resin selected from vinyl chloride, polyethylene, polystyrene, polyester, polypropylene, and polycarbonate;

[0053] 3.5 to 6.5 parts by weight of a stabilizer selected from one or two types among Ba-Zn (barium-zinc) system, Ca-Zn (calcium-zinc) system, triazole system, benzophenone system, and HALS system;

[0054] 5 to 10 parts by weight of MBS (Methacrylate butadiene styrene)-based, CPE (Chlorinated Poly Ethylene)-based, or ABS (Acrylonitrile butadiene styreneterpolymer)-based impact modifiers;

[0055] 2 to 10 parts by weight of maifan stone powder with a particle size of 1000 mesh or larger and coated with stearic acid;

[0056] 0.5 to 1.5 parts by weight of a processing aid obtained by emulsion polymerization of an acrylate-based monomer;

[0057] 100 to 125 ppm by weight of silver nanopowder having a particle size of 21 to 500 nm; comprising,

[0058] It is preferable to use the above maifan stone powder prepared by mixing 100 parts by weight of maifan stone powder with 2 parts by weight of stearic acid, stirring at room temperature up to 65-70°C for 10 minutes, and then cooling for 15-25 minutes.

[0059] The reason is to provide excellent antibacterial properties while maintaining the basic physical properties of the synthetic resin forming the cover (110) and damper (210) to antibacterialize harmful bacteria occurring in manholes or sewage collection outlets.

[0060] Since rainwater or wastewater stagnates in the aforementioned manholes or wastewater collection points and bacteria harmful to the human body proliferate, it is desirable to antibacterialize the said harmful bacteria.

[0061] 3.5 to 6.5 parts by weight of a stabilizer made by mixing one or two types among the above Ba-Zn (barium-zinc) system, Ca-Zn (calcium-zinc) system, triazole system, benzophenone system, and HALS system. If the amount of the stabilizer is less than 3.5 parts by weight, stability including thermal stability decreases, and if it exceeds 6.5 parts by weight, problems such as poor processability occur, so it is preferable to use 3.5 to 6.5 parts by weight of the above stabilizer.

[0062] The above impact modifier is a fibrous, insoluble material added to synthetic resins to increase the impact strength of a product; thermosetting resins require the largest amount of reinforcing agent, and thermoplastic resins and plastic foams are also reinforced.

[0063] Since most polyvinyl chloride (PVC) is structurally weak in terms of impact resistance, processing fluidity, and heat deformation resistance, improvements in physical properties and processability through the development of additives must be supported.

[0064] Impact modifiers are generally added to synthetic resins to reinforce impact resistance, and generally, impact modifiers are classified into three types depending on their composition.

[0065] First, there are polymer rubber systems in which MMA and SM are graft-polymerized onto diene-based rubber, such as MBS systems (Methacrylate butadiene styrene) using SBR, MMA, and SM, and ABS systems (Acrylonitrile butadiene styrene terpolymer) produced using BA, MMA, and SM as raw materials.

[0066] Second, there are chlorinated plasticizing polymers such as CPE-based (Chlorinated Polyethylene) and EVA-based (Ethene Vinyl Acetate).

[0067] Third, there are also inorganic impact-resistant modifiers coated with calcium carbonate.

[0068] The above processing aids and UV inhibitors are known ones used in synthetic resin compositions for synthetic resin pipe extrusion molding, and these components may be increased or decreased as needed.

[0069] The above maifan stone powder is coated with stearic acid so that it can be homogeneously mixed with the synthetic resin and prevent a deterioration of physical properties. That is, when maifan stone powder is added to the synthetic resin and stirred, the maifan stone powder cannot be uniformly dispersed within the synthetic resin due to the absorbency of the maifan stone powder.

[0070] The present invention is designed to improve the dispersibility of maifan stone powder within a synthetic resin by undergoing a special coating treatment process in which maifan stone powder is mixed in a ratio of 2 parts by weight of stearic acid to 100 parts by weight of maifan stone powder, stirred at room temperature up to 65–70°C for 10 minutes using a super mixer, and then cooled for 15–25 minutes to ensure uniform dispersion of such maifan stone powder.

[0071] Unlike extender fillers added in large quantities for the purpose of cost reduction, the above-mentioned maifan stone powder specially coated with stearic acid acts as a reinforcing filler added to improve processability, thereby improving physical properties and processability, resulting in less wear on the mixing processing device, and has the advantage of low volume cost due to its relatively low specific gravity.

[0072] In addition, the above maifan stone powder is used with a particle size of 1000 mesh or larger, and if mixed in an amount of less than 2 parts by weight, the antibacterial power is reduced, and if mixed in an amount exceeding 10 parts by weight, an enhanced effect cannot be expected.

[0073] In addition, conventional maifan stone powder has a particle size of approximately 325 mesh. Since maifan stone powder of this particle size causes significant wear on the extruder screw during the production of synthetic resin pipes and also significantly degrades the physical properties of the synthetic resin pipes, the present invention uses maifan stone powder that has been reprocessed to have an average particle size of 1,000 mesh or more.

[0074] The above silver (Ag) possesses antibacterial properties, and since no resistance to silver develops in bacteria and the duration of the antibacterial effect is almost semi-permanent, its scope of use is expanding. However, it has recently been revealed that excessive consumption of silver nanopowder is harmful to the human body, so the appropriate use of silver nanopowder is necessary. Accordingly, the present invention establishes an optimal composition of silver (Ag) nanopowder by considering the amount of maifan stone added, so that it is harmless to the human body and maintains antibacterial properties.

[0075] That is, the present invention is designed to add silver nanopowder in addition to the antibacterial function of maifan stone powder to maintain optimal antibacterial properties, and in order to ensure that such silver nanopowder is harmless to the human body and possesses antibacterial properties, 100 to 125 ppm by weight of silver nanopowder with a particle size of 21 to 500 nm is added. At this time, if the silver nanopowder is mixed in an amount less than 100 ppm by weight, the antibacterial activity against specific strains decreases, and if it is mixed in an amount exceeding 125 ppm by weight, an enhanced effect cannot be expected.

[0076] In addition, the fineness of the silver nanopowder mentioned above takes into account the particle size of the maifan stone powder for uniform mixing. That is, when the silver nanopowder with a particle size of 21 to 500 nm is stirred and mixed, it is positioned between the porous maifan stone powder that has been reprocessed to a mesh size of 1,000 or more, and is uniformly dispersed together with the maifan stone powder within the synthetic resin.

[0077] The antibacterial synthetic resin composition of the present invention, as described above, comprises 100 parts by weight of synthetic resin, 3.5 to 6.5 parts by weight of stabilizer, 5 to 10 parts by weight of impact modifier, 2 to 10 parts by weight of maifan stone powder coated with stearic acid having a particle size of 1000 mesh or more, and 0.5 to 1.5 parts by weight of processing aid, which are then added to a mixer, and 100 to 125 ppm by weight of silver nano powder having a particle size of 21 to 500 nm are further added to the mixer, and then stirred at a speed of 580 to 680 rpm for about 8 to 10 minutes, causing the particles to float within the mixer and generate frictional heat between them, and they are welded together and mixed by this frictional heat.

[0078] Once uniform mixing is achieved in the mixer in this manner, the mixture is naturally cooled (air cooled) to maintain the temperature inside the mixer at approximately 50 to 70°C.

[0079] As described above, the sewage and odor backflow blocking device of the present invention for manholes has the advantage of smoothly draining rainwater into the grating installed above the manhole or wastewater collection outlet as described in the effects above, blocking the backflow of odors, allowing for the free driving or parking of vehicles as it is not damaged or broken by high loads or impacts, and sterilizing harmful bacteria generated in the manhole or wastewater collection outlet. Explanation of the symbols

[0081] 100 : Body 110 : Cover 120: Drainage hole 130: Pin fixing device 131 : Pinhole 132 : Rockhole 132a: Elastic piece 132b: Rotating hole 132c: Protrusion 132d: Heavy load entry 140 : Seating ledge 200 : Drain hole blocker 210 : Damper 211 : Reinforcement rib 220 : Heavy object 221 : Round bar 230 : Pocket 231 : Heavyweight Water Breaker 240 : Rotation inducer 250 : Fixing pin 260 : Confidentiality Department

Claims

Claim 1 A flat cover (110) is positioned at the bottom of a grating installed in a manhole and fixed by being pressed down by the weight of the grating. A plurality of drainage holes (120) are formed at regular intervals along the length or width direction of the cover. Pin fixing members (130) are formed at both ends of each drainage hole on the back surface of the cover. Each pin fixing member on one side has a pin hole (131) into which a fixing pin (250) is rotatably inserted, and each pin fixing member on the other side has mutually facing elastic pieces (132a). A rotation hole (132b) is formed on the inner side of the elastic pieces to which the fixing pin is rotatably seated. On the lower sides of the elastic pieces of the rotation holes, protrusions (132c) are formed facing each other to prevent the fixing pin from detaching. A lock hole (132) is formed from the protrusions to the bottom, with a heavy object entry opening (132d) formed where the spacing between the elastic pieces gradually increases. On the edges of each drainage hole on the back surface of the cover A body (100) is provided with a seating ledge (140) formed on which the outer edge of the damper is seated, and a damper (210) having a size larger than the size of the drainage hole that blocks or opens each drainage hole. A pocket (230) is formed such that a weight (220) in the shape of a round bar (221) is seated and fixed along the longitudinal direction of one end of the damper, with one end in the longitudinal direction closed and the other end open, and a weight-holding member (231) is formed in multiple places along the open longitudinal direction to hold the weight. A rotational inducer (240) that is lighter than the weight of the damper and fills the space between the cover and the grating drain is formed to descend in a continuous manner with the damper, and a fixing pin (250) that is rotatably fitted and installed in the pin fixing member is formed on both ends of the damper on the side where the rotational inducer is formed. On the outer surface of the damper excluding the side where the rotational inducer is formed, the drainage is coupled to the seating ledge. A sealing portion (260) that maintains the airtightness of the hole is formed, and between the back surface of the damper and the rotation inducer,A drain hole blocker (200) having a plurality of reinforcing ribs (211) formed at regular intervals to improve the durability of the damper, and the cover (110) and damper (210) comprise 100 parts by weight of one synthetic resin selected from vinyl chloride, polyethylene, polystyrene, polyester, polypropylene, and polycarbonate; 3.5 to 6.5 parts by weight of a stabilizer selected from one or two types selected from Ba-Zn (barium-zinc) system, Ca-Zn (calcium-zinc) system, triazole system, benzophenone system, and HALS system; and 5 to 10 parts by weight of an MBS (methacrylate butadiene styrene) system, CPE (chlorinated polyethylene) system, or ABS (acrylonitrile butadiene styreneterpolymer) system impact reinforcing agent. A sewage and odor backflow blocking device for a manhole comprising: 2 to 10 parts by weight of maifan stone powder with a particle size of 1000 mesh or more and coated with stearic acid; 0.5 to 1.5 parts by weight of a processing aid obtained by emulsion polymerization of an acrylate-based monomer; and 100 to 125 ppm by weight of silver nano powder with a particle size of 21 to 500 nm; wherein the maifan stone powder is prepared by mixing 100 parts by weight of maifan stone powder with 2 parts by weight of stearic acid, stirring at room temperature up to 65 to 70°C for 10 minutes, and then cooling for 15 to 25 minutes. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 delete

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