JP2006002342A - Culvert and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a culvert which prevents a pipe displacement in a joint section and which possesses an anti-clogging function, and a manufacturing method therefor. <P>SOLUTION: In this culvert drain pipe which is equipped with a cylindrical pipe body, the pipe body or a thin film layer on the surface of the pipe body contains one or more anti-clogging agents which are selected from the group consisting of an alkaline earth metal, a group 11 transition metal and a group 10 transition metal, so as to prevent the deposition of iron deposits in the culvert; one end surface is equipped with an outer round surface; the other end surface is equipped with an inner round surface; both the round surfaces are made insertable; and a circular dent is formed in each of both the round surfaces. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a dark drainage pipe buried in farmland as a drainage channel and a method for producing the same.

  Agricultural land such as peat soil, glai soil, and wet volcanic soil widely distributed in Japan exhibits poor drainage. For farmlands with poor drainage, a dark drainage method has been implemented as a drainage improvement to avoid poor growth due to moisture damage of crops and to secure good crop production. For example, it is disclosed in Patent Document 1.

  FIG. 17 is a partially cutaway perspective view showing a state of implementation of a conventional dark drainage method. The gutter drainage method is the only method for eliminating the surplus water 8 that is excess water in the soil. In the dark drainage method, the farmland is excavated in a groove shape with a gradient of 1/100 to 1/1000 at a depth of a minimum of 0.6 m or less, and then the dark drainage pipe 100 is buried, and the periphery and upper part are hydrophobic. In this method, the material 12 is covered and buried. In order to quickly remove the surplus water 8 from the farmland, it is required that the water absorption and water flow capacity of the dark drainage pipe 100 located at the lowermost part in the excavation groove is maintained high.

  The cause of the decline in the water absorption and water flow function of the dark drainage pipe 100 is, for example, the displacement of the joint portion 7 of the dark drainage pipe 100 and the vertical and horizontal directions of the dark drainage pipe 100 as indicated by reference numeral 107B in FIG. As shown in FIG. 19, the arrangement in the meandering state, the inflow of fine particles such as clay and silt contained in the drainage of surplus water, the deposition of the fine particle deposit 13B, the iron complex and the bivalent Deposition of iron deposits 13A of iron oxides with iron has been pointed out.

  As shown in FIG. 17, the surplus water 8 penetrates the top soil 10, the lower soil 11, and the hydrophobic material 12, while containing clay, silt, iron complex, divalent iron, fine particles of the hydrophobic material 12, and the like in the soil. It flows into the pipe running water W containing fine particles and iron. Usually, like the running water 9 around the dark drainage pipe, it becomes normal running water 9A and flows into the dark drainage pipe 100 through the gap of the appropriate joint 107A, and may be referred to as the running water W in the dark drainage pipe (hereinafter simply referred to as “pipe running water W”). )

  However, when there is a pipe misalignment joint 107B in the joint 107 of the dark drainage pipe 100, a large amount of water flows out from one place like the pipe misalignment outflow water 9B from the pipe misalignment joint 107B vacated by the pipe misalignment. At the same time, clay and silt of the surrounding subsoil 11 and the hydrophobic material 12 and fine particles of the hydrophobic material 12 are scoured and included in a large amount of water, and then flow again into the dark drainage pipe 100 as the inflow water 9C.

  FIG. 18 is a side cross-sectional view showing a pipe misalignment state in the conventional dark drainage pipe 100. As described above, in the conventional shape, the joint portion 107 of the dark drainage pipe 100 is often the pipe misalignment joint portion 107B, and a gap of the pipe misalignment occurs depending on the connection angle θ.

  Due to such a pipe shift, the pipe running water W that has flowed again into the dark drainage pipe 100 has a condition that a large amount of clay, silt, fine particles of a hydrophobic material, iron complex, divalent iron, and the like are contained. FIG. 19 is a perspective view showing a blockage state by a deposit in the conventional dark drainage pipe 100. As shown in FIG. 19, in the pipe, the iron complex, divalent iron, etc. contained in the pipe running water W come into contact with the atmosphere, so that the dark drainage pipe is formed as iron deposits 13A of iron oxides by the iron-oxidizing bacteria FeG of the genus Gallionella. Deposit on the inner surface of 100. Thereby, the flow velocity of the in-pipe water W decreases, clay, silt, and fine particles are easily deposited, and these fine particle deposits 13B are deposited. This cycle is repeated each time it rains, and the deposit 13 is deposited, thereby closing the dark drainage pipe 100.

  In Hokkaido, about 750,000 ha of dark drainage has been constructed since the cultivation of the colonists. According to a survey report by the Hokkaido Central Agricultural Experiment Station, 13.5% of the drainage was deposited in the drainage pipe 100. In some cases, the dark drainage pipe 100 was completely blocked. When such a situation has been reached, it has often been carried out again to construct a similar drainage method at a high cost.

The conventional technique for avoiding such re-construction is as follows.
(i) Prevention of misalignment of the dark drainage pipe, such as making the joint of the pipe into a socket, connecting it completely using another socket, or inserting the joint into a trumpet or triangle A method has been devised in which protrusions are provided on the outside of a circular tube, or the outer shape of the tube is made polygonal to prevent lateral displacement.
(ii) For fine particle deposits such as clay and silt and iron deposits in a dark drainage pipe, there is a method of cleaning the inside of the pipe with a machine (Patent Document 2, etc.).

Japanese Patent Laid-Open No. 10-37168 JP 2003-10803 A

  However, in the above prior art (i), the appearance shape of the dark drainage pipe becomes complicated or requires a separate part.Therefore, damage may occur due to chipping of the product at the time of manufacture, construction and after construction. is there. In addition, it cannot cope with pipe displacement prevention due to terrain deformation during and after construction. In the above prior art (ii), the work load is large, and even if the deposit is cleaned and temporarily removed, the blockage due to the deposit will reoccur.

  In addition, according to the above prior art, reducing and preventing the pipe displacement of the dark drainage pipe and removing the deposits of the dark drainage pipe by washing can be performed separately, but the dark drainage pipe In general, when there is a blockage, both the drainage of the dark drainage pipe and the deposition of iron oxide or the like have occurred. Therefore, it is possible to prevent only the pipe displacement of the dark drainage pipe, or prevent both the pipe drainage of the dark drainage pipe and the blockage by deposits of fine particles and iron oxides over a long period of time even if the deposit is washed away. It was impossible to do and was not a fundamental solution.

  Therefore, the present invention prevents pipe misalignment by improving the shape of the dark drainage pipe without greatly changing the external shape of the dark drainage pipe, and the pipe body of the dark drainage pipe or the material of the surface of the pipe body. An object of the present invention is to provide a dark drainage pipe and a method of manufacturing the same, which retains the function of preventing blockage of the dark drainage pipe by deposits and secures water absorption and water flow functions over a long period of time.

(1) The invention according to claim 1 is a dark drainage pipe having a cylindrical pipe body, wherein the pipe body is an alkaline earth metal and a group 11 transition to prevent deposition of iron deposits in the dark drainage pipe. It contains one or a plurality of clogging preventing agents selected from the group consisting of metals and Group 10 transition metals.

(2) The invention according to claim 2 is a dark drainage pipe comprising a cylindrical pipe body, wherein alkaline earth metal is used with respect to the pipe body surface to prevent deposition of iron deposits in the dark drainage pipe, A thin film layer containing one or more clogging preventing agents selected from the group consisting of Group 11 transition metals and Group 10 transition metals is attached.

(3) The invention according to claim 3 is the dark drainage pipe according to claim 1 or 2, wherein one end face of the dark drainage pipe is a curved surface protruding outward, and the other end face is inside. When the plurality of dark drainage pipes are connected to each other, the other dark drainage with respect to the inner R face of one dark drainage pipe at the joint between adjacent dark drainage pipes. The outer R surface of the tube can be inserted.

(4) The invention according to claim 4 is characterized in that, in the dark drainage pipe of claim 3, an allowable connection angle between the adjacent dark drainage pipes is 7.5 ° at the maximum.

(5) The invention according to claim 5 is the dark drainage pipe according to claim 3, wherein a plurality of connected pipes are connected by inserting the outer R face into the inner R face at the joint portion between the adjacent dark drainage pipes. The allowable elongation of the entire dark drainage pipe is 0.45% at the maximum.

(6) The invention according to claim 6 is the dark drainage pipe according to claim 3, wherein a plurality of circular depressions are provided along the circumferential direction on each of the outer R surface and the inner R surface of the dark drainage pipe. Is formed.

(7) The invention according to claim 7 is the dark drainage pipe according to claim 3, wherein wavy undulations are formed in the circumferential direction on each of the outer R surface and the inner R surface of the dark drainage pipe. It is characterized by that.

(8) The invention according to claim 8 is characterized in that the dark drainage pipe according to any one of claims 1 to 7 contains a substance having a magnetic force with respect to the pipe body of the dark drainage pipe.

(9) The invention according to claim 9 is directed to a method for manufacturing a drainage pipe for dark drainage capable of preventing deposition of iron deposits.
A first step of preparing a tube material of the dark drainage pipe by mixing a clay containing a powder containing an alkaline earth metal which is an anti-clogging agent;
A second step of depositing the tubular material for a certain period of time and then spraying the saturated solution of the clogging inhibitor onto the tubular material;
A third step of mixing sandy silica sand with the tubular material sprayed with the saturated solution of the blocking prevention agent;
A fourth step of forming the tubular material mixed with the sandy silica sand into the shape of the dark drainage pipe, drying, and firing;
And a fifth step of leaving the fired dark drainage pipe for a certain period of time.

(10) The invention according to claim 10 is directed to a method for manufacturing a drainage pipe for dark drainage capable of preventing deposition of iron deposits.
A tube material for the dark drainage pipe is prepared by mixing clay and a powder containing one or more elements selected from the group consisting of Group 11 transition metals and Group 10 transition metals, which are blockage prevention agents. 1 process,
And a second step of forming the tube material into the shape of the dark drainage pipe, drying, and firing.

(11) The invention according to claim 11 is directed to a method for manufacturing a drainage pipe for dark drainage capable of preventing deposition of iron deposits.
A first step of forming and drying a dark drainage pipe that does not contain an anti-blocking agent;
In a bath of a liquid clogging inhibitor mixed material in which a powder containing one or more clogging inhibitors selected from the group consisting of an alkaline earth metal, a group 11 transition metal and a group 10 transition metal is mixed with a clay-based liquid binder And a second step of immersing the dark drainage pipe,
And a third step of firing the dark drainage pipe taken out from the bath.

(12) The invention according to claim 12 is directed to a method for manufacturing a drainage pipe for dark drainage capable of preventing deposition of iron deposits.
A first step of forming and drying a dark drainage pipe that does not contain an anti-blocking agent;
Liquid clogging inhibitor mixed material in which a powder containing one or more clogging inhibitors selected from the group consisting of alkaline earth metals, Group 11 transition metals and Group 10 transition metals is mixed with a clay-based liquid binder, or A second step of depositing a thin film layer on the pipe body of the dark drainage pipe by spraying any of the powdered blockage-preventing agent mixed material which is a powder containing the blockage-preventing agent;
And a third step of firing the dark drainage pipe.

(13) The invention according to claim 13 is the manufacturing method according to any one of claims 9 to 12, wherein after the dark drainage pipe is baked, the curved surface protrudes outward from one end face of the dark drainage pipe. The method further includes the step of forming an inner R surface which is a curved surface recessed inward with respect to the other end surface.

(14) The invention according to claim 14 is the manufacturing method according to claim 13, wherein a plurality of circular depressions are provided along the circumferential direction on each of the outer R surface and the inner R surface of the dark drainage pipe. It further has the process of forming, It is characterized by the above-mentioned.

(15) The invention according to claim 15 is the manufacturing method according to any one of claims 9 to 12, wherein after the dark drainage pipe is molded and before firing, the outside of one end face of the dark drainage pipe is outside. The method further includes a step of forming an outer R surface that is a protruding curved surface into an inner R surface that is a curved surface that is recessed inwardly with respect to the other end surface.

(16) The invention according to claim 16 is the manufacturing method according to claim 15, wherein a plurality of circular depressions are provided along the circumferential direction on each of the outer R surface and the inner R surface of the dark drainage pipe. It further has the process of forming, It is characterized by the above-mentioned.

(I) According to the invention according to claim 1 or 2, alkaline earth metal (calcium etc.), 11 transition metals (copper, silver etc.), group 10 By containing one or more clogging inhibitors selected from the group consisting of transition metals (such as nickel), the effect of suppressing the growth of iron-oxidizing bacteria FeGs can be obtained, and the deposition of iron deposits can be prevented.

(Ii) According to the invention according to claims 3 to 5, in addition to the above-mentioned claim 1 or 2, the shape of the joint portion of the dark drainage pipe is the outer R surface 5A and the inner R surface 5B, and adjacent dark drainage pipes. By making the end faces of each other insertable, pipe misalignment is prevented by the supporting force of the contact at the joint. In addition, by ensuring a certain range of allowable connection angle and allowable insertion amount, if it is within these ranges, an inclination angle may occur between the axes of adjacent dark drainage pipes at the time of construction and after construction, Inappropriate pipe displacement does not occur even if elongation occurs. As a result, inflow into the dark drainage pipe due to inappropriate pipe displacement can be prevented. The preferred allowable connection angle is a maximum of 7.5 ° and the preferred allowable elongation is 0.45%.

(Iii) According to the invention according to claim 6 or 7, in addition to the above-mentioned claim 3, both the R surfaces are formed by forming a circular depression or a wave shape on each of the outer R surface and the inner R surface. A moderate water flow space is secured by avoiding the close contact state.

(Iv) According to the invention according to claim 8, in addition to any of the above-mentioned claims 1-7, the underground drainage pipe or the metal detector is obtained because the tube body of the dark drainage pipe contains a magnetic substance. It is possible to enhance the detection reaction such as reflected waves. This makes it easy to detect the location where the drainage pipe is buried and repair it when a malfunction such as a pipe misalignment of the drainage pipe after the completion of the drainage.

(V) The invention according to claims 9 to 12 is a method for manufacturing a dark drainage pipe, wherein the manufactured dark drainage pipe is an alkaline earth metal (calcium or the like) on a tubular body or a thin film layer on the surface of the tubular body, By containing one or more clogging inhibitors selected from the group consisting of 11 transition metals (copper, silver, etc.) and group 10 transition metals (nickel, etc.), the effect of inhibiting the reproduction of iron-oxidizing bacteria FeGs can be obtained. Can prevent the deposit of iron deposits.

(Vi) In the invention according to claim 13 or 15, in addition to the manufacturing method according to any one of claims 9 to 12, the outer R surface 5A and the inner R surface 5B are formed in the shape of the joint portion of the dark drainage pipe. Therefore, the pipe displacement is prevented by the supporting force of the contact of the joint portion. In addition, by ensuring a certain range of allowable connection angle and allowable insertion amount, if it is within these ranges, an inclination angle may occur between the axes of adjacent dark drainage pipes at the time of construction and after construction, Inappropriate pipe displacement does not occur even if elongation occurs. As a result, inflow into the dark drainage pipe due to inappropriate pipe displacement can be prevented.

(Vii) In the invention according to claim 14 or 16, in addition to the manufacturing method of claim 13 or 15, both the outer R surface and the inner R surface are provided with a circular depression or a wave shape, A moderate water flow space is secured by avoiding the close contact state of the R surface.

(Viii) As described above, according to the dark drainage pipe and the manufacturing method thereof of the present invention, blockage due to sedimentation of deposits in the dark drainage pipe is prevented, and adjacent dark drainage pipes are firmly connected during and after construction. As well as being secured to a moderate amount, a proper water passage space is secured, and inappropriate pipe displacement is prevented. As a result, the drainage function of the dark drainage pipe can be maintained over a long period of time, and the burden of washing and reconstructing deposits can be greatly reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1A is a partially cutaway perspective view of a dark drainage pipe showing an embodiment of the present invention. The tube body 2 of the dark drainage pipe 1 has a cylindrical shape having a predetermined tube wall thickness and length and open at both ends.

  One feature of the dark drainage pipe 1 shown in FIG. 1A is the substance contained in the pipe body 2. The tubular body 2 contains an anti-occlusion agent 3 that has an effect of inhibiting the growth of iron-oxidizing bacteria FeG, that is, an effect of preventing the deposition of iron deposits 13A of iron oxides. The blockage preventing agent 3 can be contained in the tubular body 2 as follows, for example. In a dark drainage pipe using a conventional clay pot, clay occupies 80 to 90% by weight of the material of the pipe body 2. The clay has a cation exchange capacity in the range of 20 to 80 me / 100 g. In the present invention, up to nearly 100% of the cation exchange capacity of clay in this tubular material, alkaline earth metals (calcium Ca, etc.), group 11 transition metals (copper Cu, silver Ag, etc.), and group 10 transitions are used. Substitution is made with one or more elements selected from the group consisting of metals (such as nickel Ni). These elements such as calcium Ca function as a clogging preventing agent. In the present embodiment, as shown in the figure, the blocking prevention agent 3 is dispersed over the entire tube wall thickness of the tube 2 and is also exposed on the surface of the tube 2.

  An example in which the blocking prevention agent is calcium Ca will be described. Here, the ratio occupied by calcium Ca in the cation exchange capacity is referred to as lime saturation. In order to make the lime saturation of clay about 100%, a calcium-containing powder such as calcium carbonate, calcium silicate or calcium oxide and a saturated solution thereof are added to clay which is one of tube materials in the manufacturing process. Mix. In the case of calcium carbonate powder, it is mixed within 30% by weight with respect to clay. Thereafter, sandy silica sand containing a large amount of silicon is mixed in an amount of 10 to 20% by weight, molded, dried and fired. When calcium Ca reacts with silicon in the firing process, and moisture and carbon dioxide in the atmosphere react after firing, water solubility is lowered by gently chemically stabilizing calcium Ca. Thereby, the function of maintaining the pH of the surface of the tubular body 2 high for a long period of time is provided.

  For clogging prevention agents other than calcium Ca, such as copper Cu, silver Ag, etc. of group 11 transition metals or nickel nickel, etc. of group 10 transition metals, these powders and saturated solutions thereof are used in the manufacture of dark water drainage pipes. By mixing the body material with dry matter within 1% by weight, it is present in the tube 2 and exposed to the surface of the tube 2.

  When the tube material of the dark drainage pipe is a synthetic resin, the blocking agent 3 to be used is copper Cu, Ag or the like of group 11 transition metal or nickel Ni or the like of group 10 transition metal. By mixing the powder containing these elements with the tube body material, the blockage preventing agent 3 is present in the tube body 2 and exposed to the surface of the tube body 2.

  A method for manufacturing the dark drainage pipe 1 of the embodiment shown in FIG. 1A will be described in detail in FIGS. 9 and 10 to be described later.

  FIG. 1B is a partially cutaway perspective view showing another embodiment of the dark drainage pipe 1 of the present invention. The shape of the tube body 2 of the dark drainage pipe 1 of FIG. 1B is the same as that of FIG. 1A, but in the embodiment of FIG. 1B, the inner surface thin film layer 4A and the outer surface thin film layer respectively coated on the inner surface and the outer surface of the tube body 2 4B contains the blocking prevention agent 3 which has the effect of preventing the reproduction of the iron-oxidizing bacteria FeG, that is, the effect of preventing the iron deposits 13A from being deposited. Therefore, in the form of FIG. 1B, the tube body 2 itself may be made of a conventional unglazed earth tube or synthetic resin.

  The inner surface thin film layer 4A and the outer surface thin film layer 4B (both are collectively referred to as “thin film layer 4”) include, for example, a liquid clogging inhibitor mixed material obtained by mixing a clogging inhibitor powder into a binder liquid. It is formed by adhering to the surface of the pipe body 2 of the dark drainage pipe 1. For example, the tube body 2 is applied by immersing it in a bath of a liquid clogging inhibitor mixed material or spraying a liquid clogging agent mixed material on the tube body 2. The manufacturing method will be described in detail with reference to FIGS. The form of FIG. 1B can reduce the usage amount of the blocking agent 3 as compared with the form of FIG. 1A. 1B, it is essential to provide the inner thin film layer 4A, but the outer thin film layer 4B is optional. As the blockage preventing agent in the form of FIG. 1B, as in the form of FIG. 1A, an alkaline earth metal (calcium Ca, etc.), a group 11 transition metal (copper Cu, silver Ag, etc.), and a group 10 transition metal (nickel Ni) Etc.) can be used. One or more elements selected from the group consisting of:

  The shape of both ends of the dark drainage pipe 1, which is a feature common to both the embodiments of FIGS. 1A and 1B, will be described. Both ends of the dark drainage pipe 1 are used as seams when connecting a plurality of dark drainage pipes. In the dark drainage pipe 1, an outer R surface 5A that is a curved surface protruding outward is provided on one end surface of the tube body 2, and an inner R surface 5B that is a curved surface recessed inward with respect to the other end surface.

  FIG. 2 is a cross-sectional view showing a state in which a plurality of dark drainage pipes 1 shown in FIG. 1B are connected to each other. Of the adjacent dark drainage pipes 1, the other outer R surface 5 </ b> A can be inserted into one inner R surface 5 </ b> B. Adjacent dark drainage pipes 1 are firmly fixed by the supporting force of the contact 14 when the outer R surface 5A is inserted into the inner R surface. Thereby, the pipe | tube shift at the time of construction and after construction can be prevented. In addition, in the plurality of connected dark drainage pipes 1, both of the opposing outer R face 5A and inner R face 5B of the adjacent dark drainage pipes 1 are collectively referred to as “both R faces 5”.

  In FIG. 1A and FIG. 1B, a plurality of circular depressions are further provided on each of the outer R surface 5A and the inner R surface 5B at predetermined intervals along the circumferential direction at the center position of the tube wall thickness of the tube body 2. 6 is formed. By providing this circular depression 6, it is possible to prevent the capillary tension of water from occurring between the two R surfaces 5 facing each other between the adjacent dark drainage pipes 1, and to avoid the close contact between the two R surfaces 5. Secure.

  With reference to FIGS. 2-5, the pipe | tube deviation prevention means in this invention is demonstrated in detail. In order to form the pipe misalignment prevention structure of the present invention, for example, an outer R surface polishing machine 24 and an inner R surface polishing machine 31, and an outer R surface molding tool 33 and an inner R molding shown in FIGS. As shown in FIGS. 1A and 1B, the shape of the joint portion 7 of the dark drainage pipe 1 is defined as an outer R surface 5A and an inner R surface 5B using the instrument 37. As shown in FIG. 2, in the joint portion 7 between the adjacent dark drainage pipes 1, both dark drainages are supported by the support force of the contact 14 at the insertion portion (allowable insertion amount ΔL) of the outer R surface 5A and the inner R surface 5B. The tube 1 is fixed to prevent tube displacement. By ensuring an appropriate amount of insertion (for example, 2.7 mm) between the outer R surface 5A and the inner R surface 5B, the vertical lateral resistance strength that prevents tube misalignment between the dark drainage pipes is the body of the unglazed clay tube. In this case, it is about 100 N / cm. With this level of resistance strength, pipe displacement and crushing due to external pressure during construction and after construction will not occur.

  Further, an outer R surface circular recess polishing machine 38, an inner R surface circular recess polishing machine 46, an outer R surface circular recess molding instrument 47, and an inner R surface circular recess molding instrument 50 shown in FIG. As shown in FIG. 1, a plurality of circular depressions 6 are formed on each of the two R surfaces 5 along the circumferential direction at the center position of the tube wall thickness. Thereby, moderate water flow space is ensured by preventing the contact 14 from being completely sealed.

  FIG. 3 is a partial view of the tubular body 2 showing another embodiment of the shape of the joint portion 7 of the dark drainage pipe 1, that is, the shape of each end face of the tubular body 2. As shown in FIG. 3, the outer R surface 5A and the inner R surface 5B are formed on each end surface of the tube body 2, and the water flow space can be obtained by providing a wave-shaped undulation 6A in the circumferential direction on both R surfaces 5. Can be secured.

  FIG. 4 is a cross-sectional view showing a pipe misalignment state at a connection angle within an allowable range in the plurality of connected drain pipes 1 of the present invention. As shown in FIG. 4, the outer R surface 5A and the inner R surface 5B can relatively slide and displace with the R surfaces 5 in contact with the contact points 14. Therefore, in the range where the connection angle, which is the angle formed by the shafts of both dark drainage pipes 1, is within the allowable connection angle θA, an excessive gap due to pipe displacement does not occur in the joint portion 7. This allowable connection angle θA is a maximum of 7.5 ° vertically and horizontally. Thereby, it can respond to the micro distortion of a digging groove. On the other hand, in the shape of the dark drainage pipe 100 shown in FIG. 18 as the prior art, the seam portion 107 of the dark drainage pipe 100 is often the pipe misalignment seam portion 107B, and the connection angle θ is a little. However, there was an unacceptable gap between the pipes.

  FIG. 5 is a cross-sectional view showing a pipe misalignment state due to elongation within an allowable range in a plurality of dark drainage pipes 1 of the present invention connected together. As shown in the upper diagram of FIG. 5, the length of the state where the two R surfaces 5 of the adjacent dark drainage pipes 1 are most inserted into each other is defined as L1 (minimum connecting tube length), and as shown in the lower diagram of FIG. Assuming that the length after the maximum possible elongation deformation occurs is L2 (maximum connection pipe length), the allowable insertion amount ΔL, which is the maximum value of the insertion amount of the dark drainage pipe 1, is about 2.7 mm. By providing this permissible insertion amount ΔL, a maximum of 0.45% permissible elongation is secured as a margin that can prevent the pipes from being connected to each other from being dropped out. This permissible elongation can cope with terrain deformation such as earthquake after construction and land subsidence due to drying.

  As described above, even when the connection angle and the elongation are the same as those of the prior art at the time of construction and after construction due to the effect of the joint portion 7 due to the end face shape of the dark drainage pipe 1, the proper seam state Since the allowable range that can be maintained is wide, inflow of earth and sand from the joint portion 7B where the pipe misalignment has occurred is prevented.

  Still referring to FIG. Drainage that flows from the joint 7 of the dark drainage pipe 1 flows down the pipeline, but the dark drainage has a gradient of about 1/100 to 1/1000. In the joint portion 7, the outer R surface 5A of the dark drainage pipe 1 installed on the upstream side is inserted into the inner R surface 5B of the dark drainage pipe 1 installed on the downstream side. Accordingly, as shown in the upper diagram of FIG. 5, the inflow direction 9D of the wastewater flowing into the pipe line is at an acute angle with respect to the downflow direction of the in-pipe water W. On the other hand, conventionally, since the opposing end surfaces of the joint portion of the dark drainage pipe are perpendicular to each other, the drainage flowing into the pipe is bent in a 90-degree direction. Therefore, in this invention, the inflow property into the pipe | tube from the seam part 7 becomes higher than the case where it bends and flows in in the conventional 90 degree | times direction.

  Further, as shown in the upper diagram of FIG. 5, the outflow direction 9E that flows out from the pipe running water W again to the outside of the pipe must be bent at an angle of 90 degrees or more, and thus is difficult to flow out. Conventionally, even when it flows out, it is bent by 90 degrees and flows out. Therefore, when the amount of water flowing into the dark drainage pipe is large, the phenomenon of flowing out of the pipe again is reduced from the conventional dark drainage pipe, and irregular flowing water around the dark drainage pipe is eliminated. As a result, the phenomenon that clay, silt, fine particles, etc. are agitated by flowing water and flow into the pipe is reduced compared to the conventional drainage pipe.

  Next, the principle of the effect of inhibiting the growth of the iron-oxidizing bacteria FeG by the blocking agent according to the present invention, that is, the principle of the effect of preventing the deposition of iron deposits of iron oxides will be described with reference to FIGS.

  FIG. 6 is a schematic diagram showing the action and effect of each of the pipe body 2 (right side) of the dark drainage pipe of the present invention and the pipe body 102 (left side) of the conventional dark drainage pipe shown in FIG. 1A on the iron-oxidizing bacteria FeG. FIG.

  As shown in FIG. 6, in the conventional dark drainage pipe, the iron complex and divalent iron contained in the collected drainage water W in the dark drainage pipe are oxidized by the iron-oxidizing bacteria FeG to form iron deposits 13A of iron oxides. It deposits, the flow velocity of the in-pipe water W is reduced, and the fine particle deposit 13B is easily deposited. In contrast, in the dark drainage pipe of the present invention, by adding calcium Ca as the blockage preventing agent 3 to the pipe body 2 of the dark drainage pipe, the pH of the surface of the pipe body 2 is increased, and the adhesion of the iron-oxidizing bacteria FeG is prevented. By suppressing the activity and not oxidizing the iron complex and divalent iron contained in the in-pipe water W, the iron deposit 13A is not deposited and is excluded from the dark drainage.

Moreover, since the presence form of calcium Ca contained in the tubular body 2 of the dark drainage pipe is calcium carbonate and calcium silicate, it gradually dissolves in the in-pipe water W. This also raises the pH in the wastewater and can suppress the propagation of iron-oxidizing bacteria FeG. In addition, when the pipe body 2 is an unglazed earth pipe, since the saturation hydraulic conductivity of the pipe body 2 is as small as less than 10 ⁻⁷ cm / s, the leaching amount of calcium ions Ca ²⁺ is not so large and the effect is maintained for a long time.

Furthermore, since the calcium ion Ca ²⁺ dissolved in the in-pipe water W has a low concentration, it reacts with the hydrogen carbonate ion HCO ₃ ⁻ derived from carbon dioxide in the atmosphere dissolved in the in-pipe water W, and becomes porous. The unglazed surface is recrystallized in the form of a film as calcite crystals of calcium carbonate CaCO ₃ , and the calcium carbonate film CaCO _{3 of the} crystals further suppresses the adhesion and propagation of iron-oxidizing bacteria FeG. The thickness of this thin film is in an equilibrium state with the carbon dioxide concentration in the atmosphere and is almost constant.

FIG. 7 is another schematic cross-sectional view showing the action and effect on the iron-oxidizing bacteria FeG in the pipe body 2 of the dark drainage pipe of the present invention shown in FIG. 1A. In this case, the clogging preventing agent 3 is copper Cu. When the blockage preventing agent 3 is copper Cu, as shown in FIG. 7, the components of the blockage preventing agent 3 are present in the tube body 2 and are exposed on the surface of the tube body 2. The copper Cu particles themselves and the copper ions Cu ²⁺ sterilize the iron-oxidizing bacteria FeG so as not to oxidize the divalent iron. These prevent the deposition of iron deposits by iron oxides in the dark drainage pipe.

  Examples of the clogging preventing agent 3 other than those shown in FIGS. 6 and 7 include group 11 transition metal silver Ag and the like, group 10 transition metal nickel and the like. Further, in the tube containing these blockage preventing agents 3, each metal ion gradually decreases, but its water solubility is extremely low, so that a long-term function can be maintained.

  FIG. 8 is a schematic cross-sectional view showing the action of the dark drainage pipe of the present invention shown in FIG. 1B on the iron-oxidizing bacteria FeG. The left side shows the case where the blocking agent 3 contained in the thin film layer 4 formed on the surface of the tubular body 2 is calcium Ca, and the right side shows the case where the blocking agent 3 is copper Cu. About the effect with respect to iron oxidation bacteria FeG, it is the same as the effect described in FIG.6 and FIG.7, respectively.

  Examples of the blocking agent 3 other than those shown in FIG. 8 include group 11 transition metal silver Ag and the like, group 10 transition metal nickel and the like. Further, in the thin film layer 4 containing these blockage preventing agents 3, each metal ion gradually decreases, but since its water solubility is extremely low, it can maintain a long-term function.

  As a further embodiment of the dark drainage pipe of the present invention, an underground exploration radar or a metal detector or the like can be obtained by adding a magnetic substance to the pipe body 2 in the form shown in FIG. 1A or 1B. Detection reaction such as reflected waves can be strengthened. As a result, when a malfunction such as a pipe displacement of the dark drainage pipe 1 after completion of the dark drainage occurs, it becomes easy to detect the buried place of the dark drainage pipe and repair is possible.

  Next, the manufacturing method of the dark drainage pipe of the present invention described above will be described with reference to FIGS.

[Manufacturing method 1: When the tube contains an anti-blocking agent (alkaline earth metal)]
FIG. 9 is a schematic diagram showing an example of a preparation process of a tube material containing an alkaline earth metal blockage inhibitor 3 in the manufacturing process of the dark drainage pipe of the present invention shown in FIG. 1A. The case where the blocking prevention agent 3 is calcium Ca is shown as an example. As shown in FIG. 9, the clay 16 occupying 80 to 90% of the pipe material of the dark drainage pipe is mined from the earth taking site and is transported by the transport truck 15, and the clay 16 is deposited. Next, calcium carbonate containing calcium used as the anti-occlusion agent 3, calcium Ca-containing powder such as calcium silicate or calcium oxide, lime cake, shell finely pulverized powder or the like or a mixture thereof is put on the clay 16. After spraying, an operation of mixing the clay 16 and the clogging preventing agent 3 is performed using a forced stirrer 17 such as a rotary (first step). Thereby, the tube material 18 containing the blocking prevention agent 3 is prepared. The tube material 18 is deposited in a place where it hits rainwater.

  FIG. 10 is a schematic diagram showing a manufacturing process subsequent to FIG. As shown in FIG. 10, a saturated solution 20 of an anti-blocking agent is further sprayed onto the deposited tube material 18 using a sprinkler 19 or the like, and the anti-blocking agent 3 containing calcium Ca in the clay is further added. (Second step). The final amount of calcium Ca added is within 30% by weight based on the clay. Thereafter, 10 to 20% by weight of sandy silica sand containing a large amount of silicon is mixed with the tube material 18 to adjust the water content (third step), and thereafter, molded, dried and fired by a normal dark drainage pipe manufacturing process. (4th process).

  The fired dark drainage pipes are piled up in a rain-proof state and left in a rain-proof state for about one month, and are gently and chemically stabilized by moisture and carbon dioxide in the atmosphere (fifth step).

[Manufacturing method 2: When the tube contains an anti-blocking agent (other than alkaline earth metal)]
In the case of adding a powder of a copper Cu, silver Ag, nickel Ni or the like, or a mixture thereof, which is a group 11 transition metal or a group 10 transition metal other than an alkaline earth metal such as calcium Ca, as a clogging preventive agent, clay In the mixing operation, the mixture is mixed within 1% by weight (first step), and is molded, dried and fired in a normal dark drainage pipe manufacturing process (second step).

[Manufacturing method 3: In the case where the tubular body has a clogging preventive agent thin film layer]
FIG. 11 is a schematic view showing an example of a manufacturing process of the dark drainage pipe of the present invention shown in FIG. 1B. In order to form a thin film layer containing an anti-blocking agent on the surface of the pipe body of the dark drainage pipe 1, the anti-blocking agent mixed material 21 containing an appropriate anti-blocking agent is applied or sprayed onto the pipe body. . There are two types of the clogging prevention agent mixed material 21, that is, a liquid clogging prevention agent mixed material 21 </ b> A or a powdery clogging prevention agent mixed material 21 </ b> B, and one of them is used.

  In FIG. 11, the thin film layer formation method by application | coating of liquid obstruction | occlusion inhibitor mixed material 21A is shown. The liquid clogging inhibitor mixed material 21A is one or more selected from the group consisting of alkaline earth metals such as calcium Ca, group 11 transition metals such as copper Cu and silver Ag, and group 10 transition metals such as nickel Ni. A powder containing an inhibitor is mixed with a clay-based liquid binder. First, according to the manufacturing process of the normal dark drainage pipe 1, shaping | molding and drying are performed (1st process). Next, the thin film layer 4 is adhered on the pipe body 2 by submerging the dark drainage pipe 1 in a semi-plastic or solidified state after drying in a bath of the liquid blocking agent mixed material 21A (second step). Thereafter, the dark drainage pipe 1 taken out of the bath is fired (third step).

[Manufacturing method 4: When the obstructing agent thin film layer is provided on the tube surface]
FIG. 12 is a schematic view showing another example of the manufacturing process of the dark drainage pipe of the present invention shown in FIG. 1B. FIG. 12 shows a thin film layer forming method by spraying the liquid clogging agent mixed material 21A or the powdery clogging agent mixed material 21B. The liquid clogging agent mixed material 21A is the same as that described with reference to FIG. One or more powder clogging inhibitor mixed materials 21B were selected from the group consisting of alkaline earth metals such as calcium Ca, group 11 transition metals such as copper Cu and silver Ag, and group 10 transition metals such as nickel Ni. It is a mixture of powders containing an anti-occlusion agent. First, according to the manufacturing process of the normal dark drainage pipe 1, shaping | molding and drying are performed (1st process). Next, the liquid blockage preventing agent mixed material 21A or the powdery blockage preventing agent mixed material 21B is applied to the pipe inner surface spraying device 22 and the outer surface of the pipe body with respect to the dark drainage pipe 1 which is in a semi-plastic or solidified state after drying. By spraying using the spraying device 23, the thin film layer 4 is made to adhere on the pipe body 2 (2nd process). Thereafter, firing is performed (third step).

  When the thin film layer 4 is adhered and baked by the method shown in FIGS. 11 and 12 and the clogging preventive agent mixed material 21 containing an alkaline earth metal such as calcium Ca is used, a dark drainage pipe is used. Stack in the rain-proof state and leave it in the rain-proof state for more than one month. On the other hand, when the blockage preventing agent mixed material 21 containing a Group 11 transition metal such as copper or silver or a Group 10 transition metal such as nickel is used, it is handled in the same manner as the ordinary dark drainage pipe 1.

  With reference to FIGS. 13 to 16, a method for forming both end face shapes of the dark drainage pipe of the present invention will be described.

  FIG. 13 is a diagram schematically showing an example of a method for forming the shape of the outer R surface and the inner R surface in the solidified state after firing in the dark drainage pipe of the present invention. For one end surface of the dark drainage pipe 1 after firing, the outer R surface polishing portion 25 provided in the outer R surface polishing machine 24 such as a hard cutter or a grinder is used to form the outer R surface 5A. . And the shape of the inner R surface 5B is shape | molded with respect to the other end surface using the inner R surface grinding | polishing part 32 which the inner R surface grinding machine 31 comprises.

  FIG. 14 is a diagram schematically showing an example of a method for forming the shape of the outer R surface and the inner R surface before firing in the dark drainage pipe of the present invention. In the plastic state immediately after forming the dark drainage pipe 1 into a cylindrical tube body, the outer R surface 5A is scraped off with respect to one end surface using the R surface molding cutter 34 provided in the outer R surface molding tool 33. Mold. For the other end surface, the inner R surface 5B is scraped and molded using the R surface molding cutter 34 provided in the inner R molding tool 37. Alternatively, in the semi-plastic state after the dark drainage pipe 1 is formed into a cylindrical tube and dried, the outer R surface and the inner R surface are similarly scraped off by the outer R surface molding device 33 and the inner R molding device 37, respectively. Mold.

  FIG. 15 is a diagram schematically showing an example of a method for forming the shape of the circular depression 6 on each of the R surfaces 5 in the solid state after firing in the dark drainage pipe of the present invention. After forming both the R surfaces 5 on the fired dark drainage pipe 1 by the method shown in FIG. 13, a circular dent 6 is formed on the outer R surface 5A on one end surface using a circular dent polishing machine 38 for the outer R surface. Then, the circular recess 6 is formed on the inner R surface 5B on the other end surface using the circular recess polishing machine 46 for the inner R surface.

  FIG. 16 is a diagram schematically showing an example of a method for forming the shape of the circular depression 6 on each of the R surfaces 5 before firing in the dark drainage pipe of the present invention. After forming both R surfaces 5 by the method shown in FIG. 14 for the dark drainage pipe 1 in the plastic state immediately after forming before firing, the outer R surface is rounded to one end surface using a circular dimple grinder 47 for the outer R surface. The circular dent 6 is formed on the surface 5A, and the circular dent 6 is formed on the inner R surface 5B at the other end surface by using the circular dent polishing machine 50 for the inner R surface. Alternatively, after forming both R surfaces 5 by the method shown in FIG. 14 with respect to the dark drainage pipe 1 in a semi-plastic state after molding before drying and drying, using a circular dent polishing machine 47 for the outer R surface, The circular recess 6 is formed on the outer R surface 5A at the end surface of the inner surface, and the circular recess 6 is formed on the inner R surface 5B at the other end surface using the circular recess polishing machine 50 for the inner R surface.

  The dark drainage pipe of the present invention is different from the socket type and the trumpet type that have been proposed so far, and the leading edge of both R surfaces 5 at both ends in a state where the dark drainage pipe 1 in a plastic or semi-plastic state after molding is erected. Since the edge is a circle and is horizontal, it has a feature that it can be manufactured without impairing the shape of both R surfaces 5 even by firing in an upright state. In addition, since the appearance shape is the same as before, the number of bundles as a product and the volume and weight after binding are almost the same as before, and product accumulation, transportability and subsequent workability are ensured as before. The

  The dark drainage pipe 1 manufactured in this way is inserted and fixed by the two R surfaces 5 of the joint portion 7, thereby preventing inappropriate pipe displacement and ensuring an appropriate water passage space by the circular recess 6. Thus, even if the surplus water 8 shown in FIG. 17 contains soil, subsoil, fine particles of clay or silt that have permeated the hydrophobic material, iron complex or divalent iron, excess around the pipe Without increasing the fine particles of clay and silt due to scouring, the flow rate of the in-pipe water W in the dark drainage pipe 1 can be appropriately secured, so that no sedimentation occurs. In addition, by including the blocking agent 3 on the surface of the dark drainage pipe 1 that comes into contact with the wastewater, the iron complex and divalent iron in the wastewater are not deposited as iron deposits of iron oxides by iron-oxidizing bacteria. Excluded from gutter drainage. The dissolution of the component of the blockage preventing agent 3 contained in the tube body 2 of the dark drainage pipe 1 is extremely gentle from the solute mobility in the case of the unglazed tube body, and the blockage preventing effect is extended over a long period of time.

  An unglazed plate was prepared using the tube material of the dark drainage pipe used in the present invention, and its physicochemical properties were tested. This is a Pleistocene sediment used for the production of ordinary dark drainage pipes. The cation exchange capacity is 40me / 100g, and the Agricultural Society of Japan soil characteristics are 8 parts by weight of HC clay. 5 wt%, 10 wt%, 20 wt% of calcium carbonate rock powder (produced by Hokkaido Agricultural Materials Industry Co., Ltd.), which is a fine calcium carbonate powder, as a clogging preventive agent for clay materials mixed with 2 parts by weight of silica sand. % And 30 wt% mixed calcium containing tube material was used to prepare a 5 cm wide × 10 cm long unglazed plate specimen. Similarly, a 5 cm wide by 10 cm long unglazed plate specimen was prepared using a lime cake-containing tube material in which 5% by weight of dehydrated and dried lime cake powder was mixed as an anti-blocking agent.

  Also, a specimen of an unglazed plate having a width of 5 cm and a length of 10 cm was prepared for a copper-attached tube material in which fine powder containing copper as a clogging preventing agent was attached to the surface of a 0% calcium tube material.

When the physicochemical characteristics of the dark drainage pipe body of the present invention were analyzed by each of these test bodies, it was as shown in Table 1 below. In addition, the crushing strength of the test specimen in which each clogging inhibitor was mixed within the range of 20% by weight or less exceeded the quality control index value 80 N / cm of the conventional unglazed tube, and an appropriate strength could be secured.
Table 1 is a table showing the physicochemical properties of the dark drainage pipe of the present invention.

Next, these test specimens are fixed to the bottom of a large tank with a width of 1m, a length of 2.5m, and a depth of 0.6m, and drainage discharged from the dark drainage that was constructed on farmland in Biei-cho, Hokkaido. (PH 3.7, divalent iron concentration 20 mg / L, total iron concentration 220 mg / L) and the bacterial membrane of the iron-oxidizing bacteria belonging to the genus Gallionella collected from the dark drainage pipe are put in a water tank and then filled with water. Water was passed for 4 weeks at an average of 0.13 m ³ / day so that the pH of the water tank was maintained at 3 with an aqueous iron sulfate solution.

  5% by weight, 10% by weight, 20% by weight, 30% by weight calcium test specimen, 5% by weight lime cake-containing test specimen, and copper adhesion test specimen fixed to the bottom of a large water tank Although there was less than 1 mm of suspended solids on the body, the growth of iron-oxidizing bacteria belonging to the genus Gallionella was not confirmed on the specimen itself by light microscopy (1000 times). The other 5 wt%, 10 wt%, 20 wt%, 30 wt% calcium content test and copper adhesion test specimens were confirmed that no deposits were found, and the growth of iron-oxidizing bacteria was also confirmed by optical microscope (1000 times). There wasn't. In addition, adhesion of iron-oxidizing bacteria was observed on the inner wall of the large tank.

The same specimens used in Example 1, 5 wt%, 10 wt%, 20 wt%, 30 wt% calcium containing specimen, and 5 wt% lime cake containing test, copper adhesion specimen, as soil conditions (i) 0-35 cm surface layer, (ii) 35-55 cm mud flow layer, (iii) 55-95 cm peat layer, (iv) 95 cm-Gly layer bottom surface in two dark drainage pipes installed on farmland Each test specimen was installed in duplicate, and the presence or absence of the bacterial film of iron-oxidizing bacteria on the test specimen was compared with the situation. Table 2 shows the soil conditions of the test site, and Table 3 shows the water quality in the dark drainage pipe of the test site.
Table 2 is a table | surface which shows the soil physicochemical characteristic of the farmland which implemented one Example of this invention.

  Table 3 is a table | surface which shows the water quality in the dark drainage pipe which implemented one Example of this invention.

  This test site has a lot of total iron, water-soluble iron, and water-soluble sulfuric acid in the soil, and since the pH is low, the wastewater that flows into the dark drainage water is also low in pH, the total iron concentration and the divalent iron ion concentration are high, and iron oxidation It is a condition where bacteria can easily propagate. For this reason, it has been confirmed that a dark drainage pipe having an inner diameter of 60 mm is completely blocked by iron oxide within a short period of one year.

  At this test site, a dark drainage pipe with an inner diameter of 90 mm is installed in a trench of dark drainage with an excavation width of 0.2 m, an average excavation depth of 0.85 m, and an average gradient of 1/100. By filling up to 30cm from the ground surface and backfilling with topsoil, two 267m long dark drainage (dark drainage 1 and dark drainage 2) were constructed. A removable synthetic resin tube having an inner diameter of 10 cm is attached 5 m from the outlet of each dark drainage, and 5 wt%, 10 wt%, 20 wt%, 30 wt% calcium-containing test specimen, 5 wt% in the transparent tube. A lime cake-containing test specimen and a copper adhesion test specimen were fixedly installed, and were always in contact with the drainage in the dark drainage pipe.

Deposits of iron oxides are deposited in the dark drainage pipe after one month has passed since the test body was installed and in the transparent synthetic resin pipe used for the test, and this deposit is 89.4 to 93.1%. When the deposit was observed with an optical microscope, it was an iron deposit of an iron-oxidizing bacterium belonging to the genus Gallionella.
Table 4 is a table showing the effects in one embodiment of the dark drainage pipe of the present invention.

  In Table 4, the presence or absence of iron-oxidizing bacteria was described according to the following criteria. -: Bacteria not confirmed with no deposit, +: Bacteria not confirmed with deposit, or bacteria confirmed with no deposit, ++: Bacteria confirmed with deposit, ++: Bacteria confirmed with complete deposit.

  One month has passed for 5 wt%, 10 wt%, 20 wt%, 30 wt% calcium-containing test specimen, 5 wt% lime cake-containing test specimen, and copper adhesion test specimen fixedly installed in the transparent synthetic resin tube. No change was observed in the pH, CaO, or Cu content of the test specimens, confirming that there was no sudden component change in the anti-occlusive agent. In addition, the propagation state of iron-oxidizing bacteria on the surface of the test specimen is 5% by weight, 10% by weight, 20% by weight, 30% by weight calcium test specimen and 5% by weight lime cake containing test. Although black spots were observed on the body, no obvious propagation of the iron bacterium belonging to the genus Gallionella was confirmed in the test specimen itself by a light microscope (1000 times).

  Other 5 wt%, 10 wt%, 20 wt%, 30 wt% calcium test specimens and copper adhesion test specimens did not show any deposits, etc. It was not confirmed. In particular, the transparent synthetic resin tube around the copper adhesion test specimen was found not to have iron-oxidizing bacteria attached, and the effect of preventing iron deposits was high.

Grinding so that one end face of an unglazed tube having an inner diameter of 60 mm, an outer diameter of 90 mm, and a length of 300 mm is taken as the outer R face and the opposite end face as the inner R face, and both R faces are formed so as to enter about 2 mm from each other. A dark drainage pipe was manufactured.
When the dark drainage pipes formed on both R surfaces were attached and inserted by the same human power as in the dark drainage construction, there was no displacement between adjacent pipes. The force required to shift the tubes horizontally and laterally was 82 N / cm, which is close to the crushing strength of the tube. The maximum permissible angle of connection in the state where there is no gap when the drained dark pipes are connected in a slightly oblique direction was about 7 °. As a result, it was possible to completely eliminate tube misalignment. Therefore, it is possible to prevent inflow of earth and sand from the pipe line exposed by the pipe deviation into the pipe. Further, since the insertion portions on both R surfaces are about 2 mm, lateral rolling can be prevented even in a state where they are loosely inserted and are not completely adhered. At this time, the margin for the calculation of the completely tight insertion amount was 0.2% of the tube length.

[Comparative Example 1]
As in Example 1, it is a Pleistocene sediment used when producing a conventional dark drainage pipe, a cation exchange capacity of 40 me / 100 g, a soil of the Agricultural Society of Japan with 8 parts by weight of clay, and a Pleistocene sediment. Using a tube material mixed with 2 parts by weight of SL of silica sand of the Japanese Agricultural Society of Japan, a test piece of unglazed plate equivalent to a conventional dark drainage pipe with a width of 5 cm and a length of 10 cm (hereinafter referred to as “conventional test sample”) Was prepared). The physicochemical characteristics of this conventional test specimen were analyzed, and the results were as shown in Table 5 below.
Table 5 is a table showing a comparative example in the case of a conventional dark drainage pipe.

Next, this conventional test specimen was fixed to the bottom of a large aquarium with a width of 1 m, a length of 2.5 m and a depth of 0.6 m in the same manner as in Example 1, and the dark drainage constructed on farmland in Biei-cho, Hokkaido. Waste water (pH 3.7, divalent iron concentration 20 mg / L, total iron concentration 220 mg / L) and the bacterial membrane of Gallionella iron-oxidizing bacteria collected from the dark drainage pipe are filled in the aquarium. Then, water was passed for 4 weeks at 0.13 m ³ / day so as to keep the inside of the water tank at pH 3 with an aqueous ferrous sulfate solution.

  In the conventional test specimen (0% by weight of anti-occlusion agent) fixed to the bottom of a large water tank, reddish brown deposits were observed on the surface in a thickness of about 5 mm in the water state, and an iron of Gallionella genus was observed with an optical microscope (1000 times). It was confirmed that it was a breeding of oxidizing bacteria.

[Comparative Example 2]
Similar to Example 2, the conventional test body (0% by weight of anti-occlusion agent) used in Comparative Example 1 was fixed and installed on the bottom of the two drainage pipes twice, and iron oxidation to the conventional test body was performed. The presence or absence of bacterial film adhesion and its situation were compared.

The conventional test specimens that have passed one month after fixed installation are the pH and CaO, Cu shown in Table 6. There is no difference from Table 5 in Comparative Example 1, and the same iron oxides as those in Comparative Example 1 are attached. Kimono was confirmed, and 90% of the deposit was iron. When the deposit was observed with an optical microscope, it was an iron deposit of an iron-oxidizing bacterium of the genus Gallionella.
Table 6 is a table showing a comparative example in the case of a conventional dark drainage pipe.

  In Table 6, the presence or absence of iron-oxidizing bacteria was described according to the following criteria. -: Bacteria not confirmed with no deposit, +: Bacteria not confirmed with deposit, or bacteria confirmed with no deposit, ++: Bacteria confirmed with deposit, ++: Bacteria confirmed with complete deposit.

[Comparative Example 3]
As a comparison with Example 3, an excavation investigation was conducted on the occurrence of pipe misalignment in a conventional drainage pipe having a conventional shape with a flat connection. A survey of sewage drainage constructed on 155 farms in Hokkaido revealed that the rate of pipe spillage between the sewage sewage pipes was 6.5%. It was 5.1 ° when converted to a shift angle per one joint at 0.7 cm. The occurrence of this pipe misalignment has nothing to do with the number of years since construction, the form of use of farmland, or the type of soil, and most have occurred during the construction of dark drainage. This is because the conventional dark drainage pipes roll in horizontal and horizontal directions without applying force. From this, the function of preventing misalignment by both R surfaces of the present invention is effective in preventing misalignment during construction.

It is a partially cutaway perspective view of a dark drainage pipe showing an embodiment of the present invention. It is a partially cutaway perspective view of a dark drainage pipe showing another embodiment of the present invention. It is sectional drawing which showed the condition which connects the plurality of dark drainage pipes shown in FIG. 1B. FIG. 6 is a partial view of a tubular body showing another embodiment of the shape of the joint portion of the dark drainage pipe, that is, each end surface shape of the tubular body. It is sectional drawing which shows the pipe | tube misalignment state in the connection angle | corner in a tolerance | permissible_range in the dark drainage pipe of this invention connected two or more. It is sectional drawing which shows the pipe | tube shift | offset | difference state by extension within tolerance in the dark drainage pipe of this invention connected two or more. It is typical sectional drawing which shows the effect with respect to the iron oxidation bacteria FeG in each of the pipe body (right side) of the dark drainage pipe of this invention shown in FIG. 1A, and the pipe body (left side) of the conventional dark drainage pipe. It is another schematic sectional drawing which shows the effect with respect to the iron oxidation bacteria FeG in the tubular body of the dark drainage pipe of this invention shown to FIG. 1A. It is typical sectional drawing which shows the effect | action with respect to the iron oxidation bacteria FeG in the tubular body of the dark drainage pipe of this invention shown to FIG. 1B. It is a schematic diagram which shows an example of the preparation process of the tubular body material containing the blocking agent of alkaline-earth metal in the manufacturing process of the dark drainage pipe of this invention shown to FIG. 1A. FIG. 10 is a schematic diagram illustrating a manufacturing process subsequent to FIG. 9. It is a schematic diagram which shows an example of the manufacturing process of the dark drainage pipe of this invention shown to FIG. 1B. It is a schematic diagram which shows another example of the manufacturing process of the dark drainage pipe of this invention shown to FIG. 1B. In the dark drainage pipe of this invention, it is a figure which shows schematically an example of the method of shape | molding the shape of an outer R surface and an inner R surface in the solidified state after baking. In the dark drainage pipe of this invention, it is a figure which shows roughly an example of the method of shape | molding the shape of an outer R surface and an inner R surface before baking. In the dark drainage pipe of this invention, it is a figure which shows roughly an example of the method of shape | molding the shape of a circular hollow on each of both R surface in the solidified state after baking. In the dark drainage pipe of this invention, it is a figure which shows roughly an example of the method of shape | molding the shape of a circular depression on each of both R surface before baking. It is a partially notched perspective view which shows the implementation condition of the conventional dark drainage construction method. It is a sectional side view of the dark drainage which shows the implementation situation using the conventional dark drainage pipe. It is a perspective view which shows the obstruction | occlusion condition by the deposit in the conventional dark drainage pipe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dark drainage pipe 2 Tubing body 3 Block | blocking prevention agent 4 Thin film layer 4A Inner surface thin film layer 4B Outer surface thin film layer 5 Both R surface 5A Outer R surface 5B Inner R surface 6 Circular depression 6A Wavy undulation 7 Seam part 7A Proper seam part 7B Pipe slip State seam 8 Surplus water 9 Flow around the dark drainage pipe 9A Normal flow 9B Pipe slippage 9C Pipe drainage water 10 Topsoil 11 Lower soil 12 Hydrophobic material W Dark drainage drainage 13 Sediment 13A Iron deposit 13B Fine particles Sludge 14 Contact ΔL Permissible insertion amount L1 Minimum connection pipe length L2 Maximum connection pipe length θ Connection angle θA Permissible connection angle 15 Transport truck 16 Clay 17 Mixing work 18 Tubular material 19 Sprinkler 20 Occlusion inhibitor saturated solution 21 Occlusion prevention agent mixed material 21A Liquid blockage mixture material 21B Powder blockage mixture material 22 Tubular inner surface spray device 23 Tubular outer surface jet Fog device 24 Outer R surface polishing machine 25 Outer R surface polishing unit 26 R surface polishing unit connection shaft 27 Rotating motor
28 Rotating motor-fixed cylinder 29 Rotating motor cushion plate 30 Impact pressure absorbing spring 31 Inner R surface polishing machine 32 Inner R surface polishing part 33 Outer R surface molding tool 34 R surface molding cutter 35 Central cavity guide 36 R surface molding tool outer frame 37 Inner R surface molding tool 38 Circular recess polishing machine for outer R surface 39 Circular recess polishing ball 40 Circular recess polishing ball rotation power transmission surface 41 Circular recess polishing ball rotation power transmission plate 42 Circular recess polishing ball rotation power transmission plate connection shaft 43 Circular dent polishing ball rotation support shaft 44 Circular dent polishing ball fixed bearing 45 Circular dent polishing ball support shaft process nut 46 Circular dent polishing machine for inner R surface 47 Circular dent molding tool for outer R surface 48 Circular dent molding sphere 49 Circular dent molding Instrument outer frame 50 Circular recess molding instrument for inner R surface

Claims (16)

In the dark drainage pipe with a cylindrical tube body,
The pipe body contains one or more clogging preventive agents selected from the group consisting of alkaline earth metals, Group 11 transition metals and Group 10 transition metals in order to prevent deposition of iron deposits in the drainage pipe. Dark drainage pipe characterized by In the dark drainage pipe with a cylindrical tube body,
One or more clogging inhibitors selected from the group consisting of alkaline earth metals, Group 11 transition metals, and Group 10 transition metals are provided on the surface of the pipe body to prevent the deposition of iron deposits in the dark drainage pipe. A dark drainage pipe characterized by adhering a thin film layer containing it. The dark drainage pipe has an outer R surface, which is a curved surface protruding outward, and an inner R surface, which is a curved surface, the other end surface of which is recessed inward, and connects the plurality of dark drainage pipes. The outer R surface of the other dark drainage pipe can be inserted into the inner R surface of one dark drainage pipe at the joint between adjacent dark drainage pipes. The dark drainage pipe described.   4. The dark drainage pipe according to claim 3, wherein an allowable connection angle between the adjacent dark drainage pipes is a maximum of 7.5 [deg.]. By inserting the outer R surface into the inner R surface at the joint between the adjacent dark drainage pipes, the allowable elongation of the whole of the connected dark drainage pipes is a maximum of 0.45%. The dark drainage pipe according to claim 3. The dark drainage pipe according to claim 3, further comprising a plurality of circular depressions along a circumferential direction on each of the outer R face and the inner R face of the dark drainage pipe. 4. The drainage pipe according to claim 3, further comprising wavy undulations in the circumferential direction on each of the outer R surface and the inner R surface of the drainage pipe. 5.   8. The dark drainage pipe according to claim 1, wherein the pipe body of the dark drainage pipe contains a substance having magnetic force. In the manufacturing method of the dark drainage pipe that can prevent the deposition of iron deposits,
A first step of preparing a tube material of the dark drainage pipe by mixing a clay containing a powder containing an alkaline earth metal which is an anti-clogging agent;
A second step of depositing the tubular material for a certain period of time and then spraying the saturated solution of the clogging inhibitor onto the tubular material;
A third step of mixing sandy silica sand with the tubular material sprayed with the saturated solution of the blocking prevention agent;
A fourth step of forming the tubular material mixed with the sandy silica sand into the shape of the dark drainage pipe, drying, and firing;
And a fifth step of leaving the baked dark drainage pipe for a certain period of time. In the manufacturing method of the dark drainage pipe that can prevent the deposition of iron deposits,
A tube material for the dark drainage pipe is prepared by mixing clay and a powder containing one or more elements selected from the group consisting of Group 11 transition metals and Group 10 transition metals, which are blockage prevention agents. 1 process,
And a second step of forming the tube material into the shape of the dark drainage pipe, drying, and firing. In the manufacturing method of the dark drainage pipe that can prevent the deposition of iron deposits,
A first step of forming and drying a dark drainage pipe that does not contain an anti-blocking agent;
In a bath of a liquid clogging inhibitor mixed material in which a powder containing one or more clogging inhibitors selected from the group consisting of an alkaline earth metal, a group 11 transition metal and a group 10 transition metal is mixed with a clay-based liquid binder And a second step of immersing the dark drainage pipe,
And a third step of firing the dark drainage pipe taken out from the bath. A method for producing a dark drainage pipe. In the manufacturing method of the dark drainage pipe that can prevent the deposition of iron deposits,
A first step of forming and drying a dark drainage pipe that does not contain an anti-blocking agent;
Liquid clogging inhibitor mixed material in which a powder containing one or more clogging inhibitors selected from the group consisting of alkaline earth metals, Group 11 transition metals and Group 10 transition metals is mixed with a clay-based liquid binder, or A second step of depositing a thin film layer on the pipe body of the dark drainage pipe by spraying any of the powdered blockage-preventing agent mixed material which is a powder containing the blockage-preventing agent;
And a third step of firing the dark drainage pipe. A method for producing a dark drainage pipe. After firing the dark drainage pipe, an outer R surface, which is a curved surface projecting outward with respect to one end face of the dark drainage pipe, and an inner R surface, which is a curved surface recessed inward with respect to the other end face, are formed. It further has the process to do. The manufacturing method of the underdrain drainage pipe in any one of Claims 9-12 characterized by the above-mentioned. 14. The dark water drainage according to claim 13, further comprising a step of forming a plurality of circular depressions along a circumferential direction on each of the outer R surface and the inner R surface of the dark water drain pipe. A method of manufacturing a tube. The outer R surface, which is a curved surface projecting outward with respect to one end surface of the dark drainage tube, after the molding of the dark drainage tube and before firing, is a curved surface that is recessed inward with respect to the other end surface. The method for producing a drainage pipe for drainage according to any one of claims 9 to 12, further comprising a step of forming an inner R surface. The drainage of dark water according to claim 15, further comprising a step of forming a plurality of circular depressions along the circumferential direction on each of the outer R surface and the inner R surface of the dark drainage pipe. A method of manufacturing a tube.

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