Ground resistance reducing material and grounding device

Abstract

The invention provides a ground resistance reducing material and a grounding device using the ground resistance reducing material, which can contribute to reducing emission of carbon dioxide, can be used equally to a ground resistance reducing material using fossil fuel coke, and further provides a ground resistance reducing material capable of realizing weight reduction, and a grounding device using the ground resistance reducing material. The ground resistance reducing material (14) is used for being disposed between a ground electrode (11) buried in soil (12) and the soil (12), and contains carbide powder particles obtained by incomplete combustion of biomass.

Description

Technical Field

[0001] The present invention relates to a grounding resistance reducing material and a grounding device using the grounding resistance reducing material. Background Art

[0002] It is known that when a grounding electrode such as a bare copper wire is buried in the soil, a grounding resistance reducing material is arranged between the grounding electrode and the soil to reduce the grounding resistance. For example, Patent Document 1 proposes a method of burying a grounding resistance reducing material in a slot in the ground by spreading a carbon particle powder such as coke produced from coal or petroleum and a cement powder as an alkaline consolidating material as a conductive material in the grounding electrode.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent document 1: Japanese Patent Application Laid-Open No. 61-165975. Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, since the powder of coke and the like used in the grounding resistance reducing material is extracted from fossil fuels, a large amount of carbon dioxide is generated during the manufacturing process, which cannot contribute to the realization of carbon neutrality. In addition, the price of coke powder and the like has sometimes risen in recent years, and a substitute is desired. In addition, since the weight of the conventional grounding resistance reducing material has increased, when the grounding electrode is buried in mountainous areas where transportation vehicles cannot be used, it is desired to reduce the weight so as to help reduce the burden of manual transportation of the grounding resistance reducing material.

[0008] Therefore, the present invention aims to provide a ground resistance reducing material that can contribute to reducing carbon dioxide emissions and can be used on an equal footing with a ground resistance reducing material using fossil fuel coke. Another object is to reduce the weight of such a ground resistance reducing material.

[0009] Means for solving problems

[0010] In order to solve the above-mentioned problems, a ground resistance reducing material of the present invention is arranged between a ground electrode buried in soil and soil, and is characterized in that the ground resistance reducing material contains carbonized particles obtained by incomplete combustion of biomass.

[0011] According to the present invention, the carbide powder is obtained by incomplete combustion of biomass, so it is possible to reduce carbon dioxide emissions generated during the manufacturing process compared to fossil fuel coke. In addition, since the biomass is carbonized and placed in the soil, it can prevent corruption, decomposition, etc. and remain in the soil stably for a long time. Therefore, it can help reduce carbon dioxide emissions for a long time. Moreover, even if the carbide powder from biomass is used, the resistivity as a ground resistance reducing material can be suppressed to the same resistivity as when using fossil fuel coke, so a sufficient ground resistance reduction effect can be obtained.

[0012] Therefore, according to the present invention, it is possible to provide a ground resistance reducing material that can contribute to CO 2 reduction for a long period of time and can be used in the same manner as a ground resistance reducing material using coke.

[0013] The resistivity of the carbide powder of the ground resistance reducing material of the present invention can be 430 Ω·cm or less. By suppressing the resistivity to a low level, the ground resistance reducing effect can be easily ensured.

[0014] In addition, in the ground resistance reducing material of the present invention, the bulk density (bulk density) of the carbide powder can be 0.40 g / cm 3 the following.

[0015] The carbide powder obtained by the incomplete combustion of biomass has a smaller bulk density than the coke of fossil fuels, so the grounding resistance reducing material can be lightweight. The grounding resistance reducing material is easy to carry and convenient to handle before construction. During construction, the labor and time of the operation can be reduced, the grounding electrode can be easily buried and fixed, and the labor and time of construction can be simplified.

[0016] In the ground resistance reducing material of the present invention, the mass fraction of water contained in the carbide powder or granular material is preferably 7.5 wt % or less.

[0017] In this way, the solidification of the hydraulic component can be suppressed before the ground resistance reducing material is used. In addition, in the carbide powder with a high mass fraction of water, agglomerates are easily formed when the ground resistance reducing material is kneaded with water. However, by setting the mass fraction of water to the above range, the kneading operation can also be easily performed.

[0018] The ground resistance reducing material of the present invention preferably contains the above-mentioned carbide powder and hydraulic powder in a mixed state, and can integrate the ground electrode by curing.

[0019] In this way, the carbide powder and granular material can be held at a certain position by solidification, and the ground electrode and the ground resistance reducing material can be integrated to increase the area of ​​the ground electrode in contact with the soil, thereby improving the effect of reducing the ground resistance.

[0020] In this case, the carbide powder and the hydraulic powder are preferably mixed in a weight ratio of 10:90 to 50:50.

[0021] If the carbide powder and the hydraulic powder are mixed in such a mixing ratio to form a grounding resistance reducing material, the strength of the grounding resistance reducing material can be ensured when solidified in the soil, and a sufficient grounding resistance reducing effect can be ensured. In addition, the grounding electrode is buried in the grounding resistance reducing material and can be easily maintained in an integrally fixed state, so the resistivity can be suppressed to a low level and the grounding resistance reducing effect can be improved.

[0022] The grounding device of the present invention is a device in which the grounding resistance reducing material as described above is solidified and buried in soil, and a grounding electrode and the grounding resistance reducing material are integrated.

[0023] Effects of the Invention

[0024] According to the present invention, a grounding resistance reducing material that can greatly contribute to reducing carbon dioxide emissions and can be used with the same performance as a grounding resistance reducing material using coke of fossil fuel, and a grounding device using the grounding resistance reducing material can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a longitudinal sectional view showing a grounding device formed using the ground resistance reducing material according to the embodiment of the present invention.

[0026] Figure 2 It is a diagram for explaining a ground electrode of a ground device according to an embodiment of the present invention.

[0027] Figure 3 It is a diagram for explaining a method for manufacturing a grounding device according to an embodiment of the present invention.

[0028] Figure 4 It is a longitudinal sectional view showing a grounding device according to a modified example of the embodiment of the present invention.

[0029] Figure 5 It is a diagram for explaining the arrangement of ground electrodes according to another modified example of the embodiment of the present invention.

[0030] Figure 6 It is a diagram for explaining a ground electrode of a ground device according to another embodiment of the present invention.

[0031] Figure 7 This is a graph showing the change in resistivity with respect to the mixing ratio of carbide powder and cement in Example 1.

[0032] Figure 8This is a graph showing the results of measuring the change in ground resistance over time in Example 1 and Comparative Example 1.

[0033] Fig. 9 This is a graph showing the results of measuring the change in ground resistance over time in Example 2, Example 3, and Comparative Example 2.

[0034] Reference numerals:

[0035] 10: Grounding device;

[0036] 11: ground electrode;

[0037] 12, 12': soil;

[0038] 13: concave part;

[0039] 14: Ground resistance reduction material;

[0040] 15: Coated wire;

[0041] 16: Connect metal. DETAILED DESCRIPTION

[0042] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0043] The grounding resistance reducing material of this embodiment is a material used to reduce the grounding resistance by being arranged between the grounding electrode and the soil when the grounding electrodes of various electrical equipment, lightning protection equipment, etc. are buried in the soil. In this embodiment, the grounding electrode is fixed and integrated in a state of being buried inside the grounding resistance reducing material.

[0044] The ground resistance reducing material contains carbide powder and granular material obtained by incomplete combustion of biomass and hydraulic powder in a mixed state.

[0045] When placed on the soil, the material may be in a powdery or granular state or in a slurry state mixed with an aqueous liquid, but needs to solidify over time after being placed on the soil.

[0046] The carbonized powder is a powder prepared by incomplete combustion of biomass. However, it is known that various properties of the raw material biomass may change. Therefore, the inventors of the present invention investigated the conductivity, particle size, etc. using various biomasses, and confirmed that as described in the present embodiment, as the carbonized powder, for example, a carbonized powder of woody biomass such as cedar (Sugi) and cypress (Hinoki) can be used.

[0047] The incomplete combustion in producing the carbonized powder or granule may be any heat treatment that allows at least a portion of the biomass to be carbonized, and for example, a treatment in which the oxygen supply is appropriately limited and heating is performed to achieve incomplete combustion may be performed.

[0048] As such carbide powder, it is preferred to use a material having a resistivity of 430 Ω·cm or less. This is because if the resistivity of the carbide powder is too high, it is difficult to obtain a sufficient effect of reducing the ground resistance. The resistivity of the carbide powder can be measured by, for example, a four-electrode method, in a state where the carbide powder absorbs water.

[0049] The carbide powder is preferably 100 Ω·cm or less in resistivity when mixed with hydraulic powder. As long as the resistivity is 100 Ω·cm or less when mixed with hydraulic powder, charcoal, bamboo charcoal, and biochar powder materials derived from rice husks, livestock excrement, etc. may also be used.

[0050] In addition, carbide powder and granules may have a particle size in the range of 998 μm to 0.291 μm (passing 16 mesh or less). The particle size may be measured, for example, by classification using a sieve, laser diffraction, etc. (for example, laser diffraction measuring device "SALD-3100", manufactured by Shimadzu Corporation).

[0051] Such carbide powder and granules have good affinity with water, and when mixed with hydraulic powder, uneven stirring is unlikely to occur when water is added.

[0052] In addition, the bulk density of carbide powder is preferably 0.40 g / cm 3 the following.

[0053] Thus, if the density of the carbide powder is small, the grounding resistance reducing material can be made much lighter than the coke of fossil fuels, and can be easily handled and constructed. Furthermore, if the volume of the grounding resistance reducing material can be ensured, the contact area with the soil can be ensured in the state of solidification in the soil, thereby achieving a sufficient grounding resistance reducing effect.

[0054] Furthermore, the mass fraction of water contained in the carbide powder or granule is preferably 7.5 wt % or less. The mass fraction of water contained in the carbide powder or granule can be measured by a measurement method in accordance with JISM 8812:2004, for example.

[0055] When the mass fraction of water is within this range, it is possible to suppress the hardening of the hydraulic component due to the water contained in the carbide powder and particulate matter before the ground resistance reducing material is used.

[0056] In addition, in carbide powders with a high mass fraction of water, when the ground resistance reducing material is mixed with water and then placed in the soil in a slurry state, there is a tendency for agglomerates to form during the mixing operation. Therefore, by setting the mass fraction of water to less than 7.5wt%, the formation of agglomerates can be suppressed and the mixing operation can be facilitated.

[0057] On the other hand, hydraulic powder is a material that can be cured over time by mixing with water or by supplying water from the surrounding in the soil. The hydraulic powder can be cured in a state of being mixed with carbide powder and granules, thereby fixing the carbide powder and granules at a certain position in the soil and fixing the buried ground electrode at a certain position. Here, as mentioned above, the resistivity of the carbide powder and granules is at least 430Ω·cm or less, and the bulk density is 0.40g / cm 3 The carbide powder and granules preferably satisfy two or more of the above-mentioned conditions of resistivity, bulk density and mass fraction of water contained. Furthermore, the carbide powder and granules preferably satisfy all of the above-mentioned conditions of resistivity, bulk density and mass fraction of water contained.

[0058] As the hydraulic powder, any material that can be cured by water can be used as appropriate, and examples thereof include Portland cement, blast furnace cement, mixed cement such as fly ash cement, and various cements such as eco-friendly cement.

[0059] The ground resistance reducing material is a powder containing these carbide powder and hydraulic powder in a mixed state. The carbide powder satisfies any one of the above-mentioned resistivity, bulk density and mass fraction of water contained. More preferably, the carbide powder satisfies two or more of the above-mentioned resistivity, bulk density and mass fraction of water contained. Furthermore, it is preferred that the carbide powder satisfies all of the above-mentioned resistivity, bulk density and mass fraction of water contained. Other materials may be contained, for example, bentonite, inorganic salts, etc.

[0060] The mixing ratio of the carbide powder and the hydraulic powder can be set to a ratio of carbide powder:hydraulic powder of 10:90 to 50:50 by weight.

[0061] When the ratio of carbide powder and granular bodies is increased, although the effect of reducing the grounding resistance is improved, the hydraulic powder is reduced relative to the carbide powder and granular bodies, and the strength of the grounding resistance reducing material solidified when it is arranged in the soil and solidified is sometimes insufficient. In addition, sometimes the strength for burying and fixing the grounding electrode in the grounding resistance reducing material to maintain integration is insufficient, for example, sometimes cracks and breakages occur after solidification, or a gap is formed between the grounding electrode and the grounding electrode, and moisture and humidity infiltrate the soil, thereby causing corrosion to the grounding electrode. On the other hand, when the ratio of hydraulic powder is increased, although the strength is improved, the hydraulic powder becomes more relative to the carbide powder and granular bodies, and the resistivity tends to become higher, and sometimes it is difficult to obtain the effect of reducing the grounding resistance.

[0062] Next, use Figures 1 to 3 A grounding device according to the present embodiment using such a grounding resistance reducing material will be described.

[0063] The grounding device 10 is a device that buries a grounding electrode 11 connected to a grounded body in soil 12. Figure 1 As shown, the grounding device 10 has a grounding electrode 11 disposed along a groove-shaped recess 13 provided in soil 12 , and a grounding resistance reducing material 14 is laid in the recess 13 to bury the grounding electrode 11 , and the grounding resistance reducing material 14 is buried in soil 12 ′.

[0064] In the grounding device 10, a covered wire 15 connected to an electrical device, a lightning protection device, etc. (not shown) is extended, and a grounding electrode 11 is connected to the front end side of the covered wire 15. Figure 2 As shown, the ground electrode 11 is composed of a bare copper stranded wire connected to the covered wire 15 at the end thereof via a connecting metal 16, and the entire length of the bare copper stranded wire is buried in the ground resistance reducing material 14 in the soil.

[0065] The ground resistance reducing material 14 is cured over time in the soil 12 by the mixed hydraulic powder. In a completely cured state, it becomes a continuous strip-shaped cured product, and the ground electrode 11 is fixed to the soil 12 as a whole.

[0066] In order to make such a grounding device 10, Figure 3 As shown, a groove-shaped recess 13 is dug in the soil 12, a ground electrode 11 connected to a covered wire 15 is arranged along the recess 13, and a ground resistance reducing material 14 is laid in the recess 13 in such a manner as to bury the ground electrode 11. At this time, the ground resistance reducing material 14 may be laid in the recess 13 in the form of a powder or granular material, or in the form of a slurry pre-kneaded with water.

[0067] After that, the soil 12' is backfilled and compacted, and the soil 12' is further added to completely backfill the groove-shaped recess 13, thereby completing the production. Then, the grounding resistance reducing material 14 completely solidifies over time, and the grounding device 10 is completed.

[0068] According to the grounding device 10 of the present invention, electricity from the grounding electrode 11 flows to the soil 12 through the grounding resistance reducing material 14. At this time, the grounding resistance reducing material 14 with a low resistivity is arranged in a solidified state surrounding the grounding electrode 11, and the wide surface of the grounding resistance reducing material 14 is in contact with the soil, so that a sufficient grounding resistance reduction effect can be obtained.

[0069] According to the grounding resistance reducing material 14 and the grounding device 10 of the present embodiment as described above, the carbide powder is obtained by incomplete combustion of biomass, so compared with fossil fuel coke, it is possible to reduce carbon dioxide emissions generated during the manufacturing process. In addition, since the biomass is carbonized and arranged in the soil 12, it can prevent corruption, decomposition, etc. and remain in the soil 12 stably for a long time. Therefore, it can help reduce carbon dioxide emissions for a long time and contribute to the realization of carbon neutrality. Moreover, even if the carbide powder from biomass is used, the resistivity of the grounding resistance reducing material 14 can be suppressed to the same resistivity as when using fossil fuel coke, so that a sufficient grounding resistance reduction effect can be obtained.

[0070] In the present embodiment, the grounding resistance reducing material 14 contains carbide powder and hydraulic powder in a mixed state, and by solidifying them, the grounding electrode 11 and the grounding resistance reducing material 11 can be integrated. Therefore, the carbide powder can be maintained at a certain position by solidification, and by integrating the grounding electrode 11 and the grounding resistance reducing material 14, the contact area with the soil 12 can be expanded, thereby improving the effect of reducing the grounding resistance.

[0071] In addition, the carbide powder obtained by incomplete combustion of biomass has a much lower density than coke of fossil fuels, so it is possible to achieve a lighter grounding resistance reducing material 14. Therefore, the grounding resistance reducing material can be easily transported before construction, and the operation is also easy, which can reduce the labor and time of the operation during construction, and the grounding electrode can be easily buried and fixed, so the labor and time of construction are greatly simplified.

[0072] In addition, the above-mentioned embodiment can be modified appropriately within the scope of the present invention.

[0073] In the above embodiment, an example is described in which the groove-shaped recessed portion 13 is provided in the soil 12 in the horizontal direction, the grounding resistance reducing material 14 is arranged along the groove-shaped recessed portion 13, and the grounding electrode 11 is buried. Figure 4 In this case, the concave portion 13 may be filled with a grounding resistance reducing material 14 pre-mixed with water to form a slurry, and the grounding electrode 11 may be buried therein and cured to form an integrated structure.

[0074] In addition, in the above-mentioned grounding device 10, an example in which one grounding electrode 11 is buried in the soil 12 is described, but the number of grounding electrodes 11 is not particularly limited. For example, in order to reduce the grounding resistance, Figure 5 As shown, a ground electrode 11 branched into a plurality of electrodes may be buried.

[0075] In this case, if Figure 6 As shown, a connection metal 16 may be used to connect the bare copper stranded wire as the ground electrode 11 to the covered wire 15 at the middle position, thereby branching the ground electrode 11 and connecting a plurality of them in parallel, and burying them in the ground resistance reducing material 14 and arranging them in the soil 12.

[0076] Furthermore, in the above description, an example of using bare copper stranded wire as the ground electrode 11 is described, but the material and shape of the ground electrode 11 are not particularly limited as long as the conductive material is not easily corroded even when buried in the soil 12 or the ground resistance reducing material 14.

[0077] In the above-mentioned embodiment, the example in which the carbide powder and the hydraulic powder are contained in a predetermined mixed state as the ground resistance reducing material is described, but the present invention is not particularly limited to this embodiment.

[0078] Example

[0079] Hereinafter, the invention will be described in more detail by way of examples.

[0080] [Example 1]

[0081] (Manufacturing of Ground Resistance Reduction Materials)

[0082] The ground resistance reducing material 14 is prepared by mixing carbide powder particles composed of biochar A (derived from wood chips of cedar, cypress, etc.) with cement.

[0083] The resistivity change with the mixing ratio of carbide powder and cement was measured. Figure 7 As shown, if the blending ratio of biochar A is 10% or more, that is, the mixing ratio of biochar A:cement is in the range of 10:90 to 100:0, the resistivity can be made less than 100 Ω·cm.

[0084] Therefore, in Example 1, the grounding resistance reducing material 14 was prepared by uniformly mixing carbide powder and cement at a mixing ratio of 45:55, also in consideration of the above-mentioned strength relationship.

[0085] Biochar A is a powdery form of carbonized residue obtained from the thermal decomposition of wood chips to generate synthesis gas, with a bulk density of 0.15 g / cm 3 The mass fraction of water contained in the carbide powder and particles is 5.20~7.47wt%.

[0086] In addition, the resistivity of the carbide powder is 12Ω·cm. The resistivity is measured by adding water to the carbide powder and kneading it with water to absorb water. 30g of the carbide powder is placed in a test container, water is added and kneaded uniformly, and stirred. Water is absorbed in an amount that does not float, and the measurement is performed by a four-electrode method.

[0087] On the other hand, the cement is blast furnace cement type B (Portland cement is more than 40% and less than 70%, and blast furnace slag is more than 30% and less than 40%).

[0088] The ground resistance reducing material 14 uniformly mixed with biochar A and cement is packed into bags and prepared in plurality. The storage capacity of one bag is 24000cm 3 , weight: 13kg.

[0089] (Manufacture of grounding device)

[0090] like Figure 1 and Figure 2 As shown, a groove-shaped recess 13 with a width of 0.5 m, a depth of 0.7 m, and a length of 2.6 m is dug in the soil 12, and a bare copper stranded wire with a length of 2.6 m is laid along the groove-shaped recess 13 as a grounding electrode 11 connected to the covered wire 15. On the bare copper stranded wire of the grounding electrode 11, one bag of grounding resistance reducing material 14 is laid in the form of powder or granular material.

[0091] Then, soil was backfilled to a thickness of 10 cm and compacted, and the groove-shaped recessed portion 13 was completely backfilled.

[0092] (Measurement of ground resistance value)

[0093] After the grounding device was manufactured, the grounding resistance value was measured over time. The measurement results are shown in Table 1 and Figure 8 The ground resistance value was measured using a direct-reading ground resistance meter (manufactured by Hioki Electric Co., Ltd., model FT6031).

[0094] [Comparative Example 1]

[0095] The grounding device 10 was prepared in the same manner as in Example 1 except that a grounding resistance reducing material using coal coke powder (trademark "SAN-EARTH M5C", manufactured by SANKOSHA Co., Ltd.) was used, and the grounding resistance value was measured over time. The measurement results are shown in Tables 1 and 2. Figure 8 .

[0096] The bulk density of the coal coke powder that constitutes the ground resistance reduction material "SAN-EARTH M5C" is 0.72g / cm 3The mass fraction of water contained in the carbide powder was 0.5 wt %. The resistivity of the carbide powder in the kneaded state with water was 430 Ω·cm. The same cement as in Example 1 was used.

[0097] The ground resistance reduction material "SAN-EARTH M5C" is a material made by mixing coal coke powder and cement in a ratio of 45:55.

[0098] The ground resistance reducing material "SAN-EARTH M5C" is in a bagged form, and the storage capacity of one bag is the same as that of Example 1, and the weight is 25 kg.

[0099] [Table 1]

[0100]

[0101] [Example 2]

[0102] The ground resistance reducing material 14 is prepared by mixing with water in advance to form a slurry. Figure 4 The grounding device 10 shown is the same as that of the first embodiment except for the above, and the grounding resistance value is measured.

[0103] The grounding device 10 is excavated with a longitudinal hole-shaped recess 13 having a diameter of 100 mm and a depth of 3 m. A 2.6 m bare copper stranded wire is inserted into the longitudinal hole-shaped recess 13 as the grounding electrode 11. A bag of grounding resistance reducing material 14 is made into a slurry with 25 kg of water and filled into the longitudinal hole-shaped recess 13, and the soil is completely backfilled to produce the device.

[0104] After the grounding device 10 was manufactured, the grounding resistance value was measured over time. The measurement results are shown in Tables 2 and Fig. 9 The grounding resistance value is measured by the above-mentioned direct-reading grounding resistance meter.

[0105] [Example 3]

[0106] The grounding resistance reducing material 14 was prepared in the same manner as in Embodiment 2 except that the carbide powder composed of biochar B (derived from wood chips of cedar, cypress, etc.) was used, and the grounding device 10 was prepared and the grounding resistance value was measured over time. The results are shown in Tables 2 and Fig. 9 .

[0107] The biochar B that constitutes the carbonized powder is a carbonized powder obtained from the residue generated by pyrolysis of wood chips to generate synthesis gas, and its bulk density is 0.17 g / cm 3 The mass fraction of water contained in the carbide powder was 13.08%. In addition, the resistivity of the carbide powder in the state of being kneaded with water was 99 Ω·cm. The cement was the same as that in Example 2.

[0108] The ground resistance reducing material 14 uniformly mixed with the biochar B and cement was packed into bags and prepared in plurality. The storage capacity of one bag was the same as that of Example 1, and the weight was 10 kg.

[0109] In order to make the ground resistance reducing material 14 into a slurry suitable for use, 20 kg of water is required for one bag of 10 kg of the ground resistance reducing material 14 .

[0110] [Comparative Example 2]

[0111] The grounding device 10 was prepared in the same manner as in Example 2 except that the same grounding resistance reducing material (trademark "SAN-EARTH M5C", manufactured by SANKOSHA Co., Ltd.) as in Comparative Example 1 using coal coke powder was used, and the grounding resistance value was measured over time. The measurement results are shown in Tables 2 and Fig. 9 .

[0112] In order to make the ground resistance reducing material into a slurry suitable for use, 20 kg of water is required for one bag of 25 kg of the ground resistance reducing material 14 .

[0113] [Table 2]

[0114]

[0115] From the above results, it is understood that the ground resistance reducing material 14 using the biochar A or the biochar B can achieve weight reduction with the same volume as the ground resistance reducing material using coal coke.

[0116] Furthermore, when the grounding electrode 11 is buried in the soil 12 with the same volume as the grounding resistance reducing material using the biochar A or biochar B, the grounding resistance value can be achieved to the same degree as the grounding resistance reducing material using the coal coke.

[0117] As a result, it was confirmed that the grounding resistance reducing material 14 of the example can be used in the same manner as the grounding resistance reducing material using fossil fuel coke in the comparative example.

Claims

1. A ground resistance reducing material, characterized in that: The carbonized material is used to be arranged between a ground electrode buried in the soil and the soil, and contains carbonized particles obtained by incomplete combustion of biomass.

2. The ground resistance reducing material according to claim 1, wherein: The resistivity of the carbide powder is 430 Ω·cm or less.

3. The ground resistance reducing material according to claim 2, wherein: The bulk density of the carbide powder is 0.40 g / cm 3 the following.

4. The ground resistance reducing material according to claim 3, wherein: The mass fraction of water contained in the carbide powder is less than 7.5wt%.

5. The ground resistance reducing material according to claim 1, wherein: The carbide powder and hydraulic powder are contained in a mixed state, and the ground electrode can be integrated by solidification.

6. The ground resistance reducing material according to claim 2, wherein: The carbide powder and hydraulic powder are contained in a mixed state, and the ground electrode can be integrated by solidification.

7. The ground resistance reducing material according to claim 3, wherein: The carbide powder and hydraulic powder are contained in a mixed state, and the ground electrode can be integrated by solidification.

8. The ground resistance reducing material according to claim 4, wherein: The carbide powder and hydraulic powder are contained in a mixed state, and the ground electrode can be integrated by solidification.

9. The ground resistance reducing material according to claim 5, wherein: The carbide powder and the hydraulic powder are mixed at a weight ratio of 10:90 to 50:

50.

10. The ground resistance reducing material according to claim 6, wherein: The carbide powder and the hydraulic powder are mixed at a weight ratio of 10:90 to 50:

50.

11. The ground resistance reducing material according to claim 7, wherein: The carbide powder and the hydraulic powder are mixed at a weight ratio of 10:90 to 50:

50.

12. The ground resistance reducing material according to claim 8, wherein: The carbide powder and the hydraulic powder are mixed at a weight ratio of 10:90 to 50:

50.

13. A grounding device, wherein: The grounding resistance reducing material according to any one of claims 1 to 12 is solidified and buried in soil, and the grounding electrode is integrated with the grounding resistance reducing material.

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