JPS62172684A - Resistance heating unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resistance heating element that utilizes the heat generation effect produced by passing a current through a conductive resistor.

Electrical conductors (conductive resistors) with appropriate resistivity, such as carbon, graphite, silicon carbide, germanium, nickel chromium,
When current is passed through iron chromium, molybdenum silicide, zirconia heating elements, tank chromite heating elements, etc., heat is generated. Direct resistance heating is internal heating of the heating element itself, so it is easy to obtain high temperatures and has high thermal efficiency, so it can be used as a various heat source. has been done. However, the above-mentioned direct resistance heating involves passing a current directly through a conductive resistor, and its applications are limited.

The object of the present invention is to provide a resistance heating element capable of generating heat even in a hydraulic system, a magnesium cement system, a sintered system, a metal system, a glass system, or a synthetic resin system. One of the resistance heating elements of the present invention that meets the purpose is characterized by being composed of a uniformly dispersed system of a conductive resistor and a conductor, and the other one is characterized by having an anti-oxidation layer or an insulating layer on the surface of the resistance heating element. It is characterized by having a layer.

Example 1 10 parts by weight of a 20% citric acid aqueous solution was added to 5 parts by weight of a 20% cobalt chloride aqueous solution, and then an ammonia content of 2.8% was added.
An additive was prepared by adding 20 parts by weight of ammonia water, and 100 parts by weight of water containing 2 to 20% of the additive was kneaded with 400 parts by weight of Portland cement. After curing, when an electric current was applied, heat was generated.

Example 2 250 parts by weight of Portland cement was added to 125 parts by weight of water containing 2 to 20% of the additive of Example 1 and kneaded to make a slurry. 50 parts by weight of graphite was added to the slurry and kneaded, and after hardening. When a current was passed through it, it generated heat.

Example 3 250 parts by weight of Portland cement was added to 125 parts by weight of water containing 2 to 20% of the additive of Example 1 and kneaded to make a slurry, and 30 parts by weight of graphite and 30 parts by weight of silicon carbide were added to the slurry.
Parts by weight were added and kneaded, and when an electric current was applied after curing, heat was generated.

Example 4 A citric acid aqueous solution was prepared by adding 95 parts by weight of water to 4 parts by weight of citric acid, 1 part by weight of manganese was added to the citric acid aqueous solution to dissolve it, and then 20 parts by weight of ammonia water with an ammonia content of 2.8% was added. Add 2 to 20 parts by weight to make an additive.
100 parts by weight of water and 400 parts by weight of Portland cement were mixed, and after curing, an electric current was applied to generate heat.

Example 5 250 parts by weight of Portland cement was added to 125 parts by weight of water containing 2 to 20% of the additive of Example 4 and kneaded to make a slurry. 50 parts by weight of graphite was added to the slurry and kneaded, and after hardening. When a current was passed through it, it generated heat.

Example 6 250 parts by weight of Portland cement was added to 125 parts by weight of water containing 2 to 20% of the additive of Example 4 and kneaded to make a slurry, and 30 parts by weight of graphite and 30 parts by weight of silicon carbide were added to the slurry.
Parts by weight were added and kneaded, and when an electric current was applied after curing, heat was generated.

Six examples of hydraulic resistance heating bodies have been described above, and in all of them, metals (cobalt, manganese) or metal compounds are uniformly dispersed between solid cement particles as ions or colloids in a solution state. It is thought that the cement-based cured material is made into a conductor by solidifying or reacting due to reduction or the like, bonding or filling the spaces between cement particles, and solidifying or by the continuity of the reactant. When an electric current is passed through a conductor, it generates heat according to its resistivity, so adding a conductive resistor such as graphite or silicon carbide will naturally generate heat, but when a conductive resistor is added, the solidification of the conductor Alternatively, the reactant causes a current to flow through the conductive resistor and the conductive resistor also generates heat.

In addition to Portland cement, hydraulic materials used in hydraulic resistance heating elements include blast furnace cement, fly-ash cement, jet cement, early-strength Portland cement, alumina cement, gypsum, water, calcium hydroxide, pozzolan, etc. Those that harden reactively or in the presence of water can be used, as well as magnesium cement (a concentrated solution of magnesium chloride is kneaded with magnesium oxide), and solutions of metals or metal compounds include cobalt chloride, nickel chloride. , aqueous solutions of metal chlorides such as ferric chloride, aluminum chloride, manganese chloride, chromic chloride, magnesium chloride, calcium chloride, strontium chloride, barium chloride, lithium chloride, sodium chloride, potassium chloride, rubidium chloride, and aluminum sulfate. aqueous solution,
A solution of manganese dissolved in acid, or a solution of manganese dissolved in acid and aqueous ammonia added, or two of these.
The above mixture or mixed reaction solution is used. Conductive resistors include carbon, graphite, silicon carbide, molybdenum silicide, germanium, nickel chromium, iron chromium, chromium,
One or more of iron oxide, silicon nitride, zirconia heating element, tanchromite heating element, etc. can be used.

The reason why citric acid was added to the additive in the above example is that if the cobalt chloride aqueous solution is added directly, it will react with the alkaline solution of cement and immediately gel, making it difficult to disperse the metal compound well. This is because adding citric acid slows down the reaction and seems to improve dispersion, and the reason why citric acid was added to manganese was to dissolve manganese. The reason why ammonia water was added to both was to prevent the strength of the cement-based cured product from decreasing due to the addition of citric acid. The acid added is not limited to citric acid, but also hydroxycarboxylic acids including sugar acids and their salts (specifically tartronic acid, malic acid, tartaric acid, citric acid, gluconic acid, glucosaccharic acid, gulonic acid, Glucuronic acid, ascorbic acid, glycolic acid, glyceric acid, trihydroxyglutaric acid, tetrahydroxyacibic acid, 2-ketoglutaric acid,
An aqueous solution of 2-ketogluconic acid, oxalacetic acid, and their salts such as sodium, potassium, calcium, lithium, ammonium, magnesium, etc., and a very diluted solution of sulfuric acid or nitric acid are used. Further, the alkaline liquid to be added is not limited to aqueous ammonia, and one or more of alkaline liquids such as aqueous ammonia, aqueous sodium bicarbonate solution, aqueous caustic soda solution, and aqueous soda carbonate solution can be added. If the additives react to form a gel and precipitate, multiple additives can be added to the water used. In addition, in the example, 1 part of acidic liquid was added to the additive.
Citric acid aqueous solution was added as an example, and ammonia water was added as an example of alkaline liquid, but the properties of hydraulic substances such as gypsum and alumina cement are different, and when acidic liquid and alkaline liquid are added, not added, and when added. The amount of addition can be selected depending on the properties of the hydraulic substance. For example, in the case of gypsum, ammonia water is not necessarily necessary. Further, since the cured magnesium cement material is itself a conductor, it is not necessarily necessary to add additives, and it can be made into a heating element simply by adding a conductive resistor, kneading, and hardening.

Next, the synthetic resin resistance heating body will be explained.

Example 7 20 parts by weight of Mohiton manufactured by Hoechst Synthesis Co., Ltd. was added to 10 parts by weight of the additive used in Example 1 and mixed, 25 parts by weight of graphite was added thereto, kneaded, and then heated and cured to harden. When a current was applied after curing, it generated heat.

Example 8 35 parts by weight of Mohitone was added to 20 parts by weight of the additive used in Example 4 and mixed, and 35 parts by weight of graphite was added thereto and kneaded, heated and cured, and after curing, an electric current was applied. Then I developed a fever.

Example 9 5 parts by weight of the additive used in Example 1 and 25 parts by weight of Mohiton were mixed, 20 parts by weight of Portland cement was added to this, kneaded, 10 parts by weight of graphite was added and kneaded, and after hardening. When a current was passed through it, it generated heat.

Example 10 10 parts by weight of the additive used in Example 4 and 20 parts by weight of Mohitone were mixed, 20 parts by weight of Portland cement was added thereto and kneaded, and then 10 parts by weight of graphite was added and kneaded. When I flushed it, it developed a fever.

Although four examples of synthetic resin resistance heating bodies have been described above, the additives do not necessarily include alkaline liquids such as ammonia and acidic liquids such as citric acid. It goes without saying that solutions of other metals or metal compounds may be used as additives, and those without the addition of a conductive resistor such as graphite or silicon carbide can also be used as a resistance heating element.

Further, the synthetic resin system may be thermosetting or thermoplastic. A synthetic resin resistance heating element can be used as a relatively low-temperature heating element. Next, the sintered resistance heating element will be explained.

Example 11 A pottery raw material was kneaded with water containing 2 to 20% of the additive used in Example 1 or 4, shaped, dried, and fired to obtain a pottery-based resistance heating body.

Example 12 A mixture of Portland cement and the same weight of pottery raw material was kneaded with water containing 2 to 20% of the additive used in Example 1 or 4, molded, hardened, and fired to obtain a pottery-based resistance heating body. Ta.

Example 13 Graphite and silicon carbide were mixed in the mixture of Examples 11 and 12, dried or hardened, and then fired in a non-acid atmosphere to obtain a sintered resistance heating element.

Although we have described the sintered resistance heating element above, other additives may be used as additives, such as silica-based hardened products using a silica reaction or cement-based hardened products that are heated and fired to create a sintered resistance heating element. It can also be a heating body. Depending on the type, solidified or reacted metals or metal compounds can become roasting agents;
Binds particles such as cement.

Metals such as gold, silver, copper, iron, and nickel are conductors, and when a conductive resistor such as carbon, silicon carbide, graphite, and silicon nitride is uniformly dispersed in the metal, a resistance heating element is obtained.

Example 14 25 parts by volume of graphite, 25 parts by volume of silicon carbide, 50 parts by volume of stainless steel
A volumetric portion of the homogeneous mixture was sintered using a powder metallurgy method to obtain a metal resistance heating element.

It goes without saying that in the above embodiments, stainless steel may be replaced with other metals, and graphite and silicon carbide may be replaced with other conductive resistors. Also, if the specific gravity of the conductive resistor and the metal are approximately the same,
It can be made by dispersing a conductive resistor in molten metal and solidifying it.

Glass also becomes a conductive resistor at high temperatures. Colored glass is made by dispersing colloidal particles of metal into the glass. For example, colored glass is made by dispersing copper or gold in potassium lead glass, and yellow glass is made by dispersing selenium oxide, uranium oxide, and so on in soda lime glass. Blue glass is made with cobalt, blue-green glass is made with copper oxide, and green glass is made with chromium. However, increasing the amount of metal or metal compound added increases conductivity. It becomes a body and generates heat when an electric current is passed through it. A glass resistance heating element is obtained by mixing and solidifying a conductive resistor such as molybdenum silicide.

Example 15 90 parts by weight of molten soda lime glass and 1 to 1 part of cobalt
0 parts by weight was added and kneaded to uniformly disperse cobalt in colloidal form, and the cobalt was cooled and solidified to obtain a glass resistance heating element.

Example 16 90 parts by weight of molten soda lime glass and 1 to 1 part of cobalt
0 parts by weight was added and kneaded to make cobalt into a colloid and dispersed, then the same amount of molybdenum silicide was added and kneaded, and the mixture was cooled and solidified to obtain a glass resistance heating element.

Although we have explained the glass-based resistance heating element above, water glass, which is a type of glass, is also made by adding a metal compound solution to it and solidifying it, or by adding a metal or metal compound to molten water glass and dispersing it, then cooling and solidifying it. Alternatively, by adding and dispersing a conductive resistor thereto, a glass-based resistance heating body can be obtained.

The above explanation has been about a cured resistance heating body in which a conductive resistor and a conductive conductor are integrated. It flowed. It goes without saying that an insulating layer is provided on the surface of the resistance heating element. Further, the resistance heating body is not limited to a cured product, and may be a powder or fiber in which a conductive resistor and a conductor are uniformly dispersed.

Figure 1 shows a homogeneous dispersion system 1 of 1 volume part of graphite powder, 1 volume part of silicon carbide powder, and 2 volume parts of stainless steel powder compressed and filled into an insulating box 2, where 2a is an insulating lid and 3 is an electrode. , 4 is a power supply. FIG. 2 shows the same homogeneous dispersion system 1' as in FIG. 1, with plate electrodes 3, 3' provided on both sides of the compressed body, 2' being an insulating frame, and 4 being a power source. In the homogeneous dispersion system 1.1' in Figures 1 and 2, the conductive resistor and the conductor are powders, such as graphite powder and stainless steel fibers, silicon carbide fibers and stainless fibers, carbon fibers and stainless steel powder, etc. Alternatively, it may be a uniformly dispersed system of fibers. When the electrodes on both sides are connected to a power source, they generate heat. In addition, in Figures 1 and 2, only a conductive resistor such as carbon is used in the form of powder or fiber instead of a uniformly dispersed system.
Oxidation can be prevented by filling in nitrogen gas or by vacuum suction. In particular, in Fig. 2, the plate electrode is made of a thin metal sheet such as metal foil, the insulating frame 2' is made of insulating adhesive, and a flammable resistance heating element is used. Although both of them generate heat when energized, a uniformly dispersed system is considered to be more effective. In addition, even when using a uniform dispersion system as shown in FIGS. 1 and 2, oxidation may be prevented by nitrogen gas injection or vacuum suction. An insulating layer is provided on the surface.

Next, specific examples of solidified or cured material-based resistance heating bodies will be described. Figures 3 and 4 show two examples of resistance heating bodies, 1
'' is a solidified or hardened material-based resistance heating element, 3'' is an electrode embedded in the solidified or cured material-based resistance heating material 1'', 4 is a power source, and when the electrodes 3'' and 3'' on both sides are connected to the power source 4. Electric current flows through the solidified or cured material resistance heating element to generate heat.The electrodes can be attached to both sides of the resistance heating element removably or by pressure bonding.Also, as shown in FIG.
The resistance heating element 1'' may be manufactured by casting the raw material using molds ', 3''' and solidifying or hardening it.

An insulating layer is provided on the surface.

Figure 6 shows an example of an electrode, in which electrodes 3'', 3'' on both sides are fixed in place by weaving, knitting or other suitable means with insulated wire 5, forming a resistance heating element. Solidify or harden by embedding it in the raw material to solidify or harden it,
It can be a resistance heating element.

Although many examples of resistance heating bodies have been described above, stainless steel electrodes, artificial graphite electrodes, carbon electrodes, self-firing electrodes, etc. can be used as the electrodes, and the current may be direct current or alternating current. Further, the solidified or cured resistance heating body may be a foam-containing body, or may be one in which fibers are dispersed for the purpose of reinforcement. The fibers may also be electrically conductive or electrically conductive resistors. Hydraulic type, magnesium cement type, synthetic resin type and sintered type resistance heating elements are
It can be produced by further adding a metal oxide such as iron oxide, a metal conductive powder, or a silicate-based liquid such as silicate sol, water glass, or silicon to the raw material. In addition, when the resistance heating element is hydraulic, the raw material may be injection molded, press molded, press demolded, or vibration press molded.
For curing, normal curing, underwater curing, autoclave curing, etc. can be performed. In addition, by placing a resistor or other body in the water and connecting the electrode to a power source to generate heat, underwater temperature curing can be achieved.

Further, the resistance heating element can be provided with an insulating layer or an anti-oxidation layer on its surface. Incorporating a uniformly dispersed powder or fibrous system within nitrogen gas is one way to configure the antioxidant layer. The insulating layer or antioxidant layer can be made by applying an insulating paint or an antioxidant paint to the surface of the resistance heating element, or by applying an insulating or antioxidant property and baking it, or by applying an insulating or antioxidant paint to the surface of the resistance heating element and baking it. It can be produced by depositing an antioxidant and an antioxidant on the surface of the resistance heating element by physical vapor deposition, chemical vapor deposition, or physicochemical vapor deposition.

Glass and various oxides can be used as the deposited material. When the insulating layer also serves as an anti-oxidation layer, it may be a single layer, but the insulating layer and the anti-oxidation layer may be provided separately.

If something or a method used in one embodiment of the present invention is appropriate for another embodiment, it can be used, utilized, or applied to the other embodiments without changing the gist thereof.

The present invention is configured as described above, and can generate heat in a hydraulic system, a magnesium cement system, a sintered system, a synthetic resin system, a glass system, or a metal system, and can select the type of conductive resistor and conductor. The exothermic temperature can be adjusted to a desired temperature by adjusting the formulation, and a thermostat is not necessarily required. Also, a conductive resistor and a conductor may have the same low efficiency, and heat will be generated regardless of whether the low efficiency of the conductor is greater or less than the low efficiency of the conductive resistor, but the low efficiency of the conductor When is larger, the current flows more uniformly through the conductor and the conductor resistor, and heat is generated more uniformly in a shorter time. Furthermore, in a solidified or cured material-based resistance heating element, even if the blending ratio of the metal or metal compound is small, as long as the conductive resistors are in direct contact with each other, current will flow and heat will be generated. Additionally, additives made by adding an acidic liquid such as citric acid to a metal or metal compound solution, and additives made by adding an alkaline liquid such as aqueous ammonia, for example, the additives used in Examples 1 and 4, and conductive resistors, such as Phosphorous graphite is a well-mixed slurry,
If it is sealed, it will remain muddy. Even if a small amount of Portland cement or clay is added, it remains muddy when sealed. Furthermore, when the muddy material is left in the air or heated, it solidifies or hardens, and the solidified or hardened material, its crushed material, and the muddy material also serve as resistance heating bodies.

That is, even if the material is mud-like, it is included in the present invention as long as it is a uniformly dispersed system of a conductor and a conductive resistor. When mixing a conductive resistor such as phosphorescent graphite or earthy graphite with a conductor such as a metal or a metal compound, use a solution of the metal or metal compound directly, or an acidic liquid such as citric acid aqueous solution or ammonia water. An alkaline liquid may be added to mix or mix with the conductive resistor. The resistance heating body of the present invention can be used in the form of a solidified or cured product, in the form of fibers or powder, or in the form of mud, and can be used on roofs, roads, pedestrian bridges, overpasses, runways, It can be installed on water pipes, railroad crossing points, ship decks, water gates, stairs, etc. to melt snow,
In addition to being able to prevent freezing, it can also be used as a heat source for floor heating, heaters, food vending machines, cookers, kettle pots, rice cookers, heating combination magic, dryers, boilers, pig farming, incubation, fish farming, greenhouses, etc. It has many uses, including being able to be used for cultivation. In particular, when a resistance heating element is set at the bottom of a container such as a bowl, plate, pot, cauldron, or bathtub, the contents can be efficiently heated and the container itself can generate heat. When the resistance heating element is made of metal, it can be insulated and prevented from oxidation by enameling, etc., and is excellent in economy, cleanliness, and fire resistance.

[Brief explanation of drawings]

FIGS. 1 to 5 are explanatory views of five examples of resistance heating bodies, and FIG. 6 is an explanatory view of one example of electrodes.

Claims (8)

[Claims] (1) A resistance heating body comprising a uniformly dispersed system of a conductive resistor and a conductor. (2) The resistance heating body according to claim 1, wherein the conductive resistor and the conductor are uniformly dispersed in powder or fiber form. (3) The resistance heating body according to claim 1, which is a solidified or cured product in which a uniformly dispersed system of a conductive resistor and a conductor is integrated. (4) The resistance heating element according to claim 1, wherein the solidified or hardened material is hydraulic, magnesium cement, sintered, metal, glass, or synthetic resin. . (5) The resistance heating body according to claims 3 and 4, wherein the solidified or cured product is a foam-containing body. (6) The resistance heating body according to claims 3 to 5, characterized in that fibers are dispersed in the solidified or cured product. (7) The resistance heating body according to claim 6, wherein the fibers dispersed in the solidified or cured product are a conductive resistor or a conductor. (8) A resistance heating body characterized in that an anti-oxidation layer or an insulating layer is provided on the surface of a uniformly dispersed system of a conductive resistor and a conductor.