CUI, Cheng-Zhe (Shinyongsan Bldg, 511196, Hangangno 2-ga, Yongsan-g, Seoul-si 140-749, KR)
CUI, Cheng-Zhe (Shinyongsan Bldg, 511196, Hangangno 2-ga, Yongsan-g, Seoul-si 140-749, KR)
| CLAIMS
[Claim 1 ]
A heating element, comprising: a frame made of a quartz or ceramic component; a heating film deposited on an outer surface of the frame in the form of a coating film and made of metal composition containing tin as a main component; and electrode bands formed at both ends of the heating element and connected to an external power source.
[Claim 2]
The heating element as claimed in claim 1, wherein the heating film is formed through vapor deposition of metal composition, which comprises:
30 to 50 weight % of stannic chloride (SnCl 4 ); 2 to 5 weight % of antimony chloride (SbCl 3 );
0.5 to 2 weight % of boric acid (H 3 BO 3 ); 0.1 to 1 weight % of ferric chloride (FeCl 3 ); and an ethanol solvent.
[Claim 3]
The heating element as claimed in claim 1 , wherein the frame is any one selected from the group consisting of a quartz tube, a ceramic tube, and a porcelain enamel tube.
[Claim 4] The heating element as claimed in claim 1, wherein the heating film has a power density range of 0.25 to 1.00 W/cm 2 .
[Claim 5]
The heating element as claimed in claim 1, wherein the frame has a sectional shape selected from the group consisting of circle, ellipse, triangle, quadrangle, pentagon and hexagon.
[Claim 6]
The heating element as claimed in claim 5, wherein the frame has upper and lower ends with different diameters.
[Claim 7]
The heating element as claimed in claim 5, wherein the frame is a circular rod.
[Claim 8]
The heating element as claimed in claim 1 , wherein the electrode band is formed of an adhesive which comprises 10 weight % of silica, 60 weight % of silver and 30 weight % of pine resin.
[Claim 9]
The heating element as claimed in claim 1, wherein the number of electrode bands varies from two to three depending on a length of the frame and a required amount of heat.
[Claim 10]
A fluid heating apparatus, comprising: a heating element according to any one of claims 1 to 6, 8 and 9, through which fluid flows; and an assembling fixture coupled to both ends of the heating element and formed with a fluid passage therein to communicate with the interior of the heating element such that the fluid flows through the fluid passage and the interior of the heating element.
[Claim 11 ]
The fluid heating apparatus as claimed in claim 10, wherein metal electrode rings are coupled around the electrode bands of the heating element to supply electric power to the heating film.
[Claim 12]
The fluid heating apparatus as claimed in claim 10, wherein the assembling fixtures are provided in pair, and each of the assembling fixtures includes a thread for allowing the end of the heating element to be fitted therein, a connection port which communicates with the fluid passage and is formed in an inner side of the assembling fixture facing each other, and a fluid inlet or outlet hole for the fluid formed at an opposite outer side of the assembling fixture.
[Claim 13]
The fluid heating apparatus as claimed in claim 10, wherein the heating element and the assembling fixture are coupled to each other by means of a heat-resistant gasket which surrounds both ends of the heating element and is fitted into a connection port to hermetically seal a coupling portion between the heating element and the assembling fixture, and a flange joint which is positioned on the heat-resistant gasket and is engaged with a thread formed in the connection port of the assembling fixture when an end of the heating element is inserted therein.
[Claim 14]
The fluid heating apparatus as claimed in claim 10, wherein the heating element and the assembling fixture are coupled to each other using fixing bolts which pass through a plurality of fixing holes formed in an outer periphery of the assembling fixture and are engaged with nuts.
[Claim 15]
The fluid heating apparatus as claimed in claim 10, wherein the fluid passage of the assembling fixture is configured to connect inner passages of the heating elements in series with each other. [Claim 16]
The fluid heating apparatus as claimed in claim 10, wherein the fluid passage of the assembling fixture is configured to connect inner passages of the heating elements in parallel with each other.
[Claim 17]
The fluid heating apparatus as claimed in claim 10, wherein the electrode bands of the heating element are formed by causing adhesives to be coated on the heating film at both ends and the middle of the heating film. |
HEATING ELEMENT AND FLUID HEATING APPARATUS USING THE SAME
Technical Field The present invention relates to a heating element and a fluid heating apparatus using the same, and more particularly, to a heating element and a fluid heating apparatus using the same wherein a heating film is formed on a surface of a frame to generate heat which in turn is transferred to a fluid to heat the fluid.
Background Art
Conventional heating elements have been divided into a type in which a nichrome wire installed within a quartz tube to generate heat using electric energy and a type in which an adhesive mixed with carbon powders is coated on an outer surface of a quartz tube. In the former case, a heating element using a nichrome wire generates heat at a high temperature of 800°C or above, and thus, there are some problems of large power consumption due to heat radiation, very low heat conversion efficiency due to a small heating area, and a short service life due to very frequent occurrence of the short-circuit of coils. Further, in the latter case, a heating element in which an adhesive and carbon powders serving as main components are mixed with each other and then coated on an outer surface of a quartz tube exhibits very lowered adhesive force of the adhesive at a high temperature, and thus, a heating film (also referred to as a "heating layer") coated on the quartz tube comes off from a wall of the quartz tube to cause a gap therebetween, thereby greatly deteriorating heating effects.
Disclosure Technical Problem
Accordingly, the present invention is conceived to solve the problems in the prior art. An object of the present invention is to provide a heating element capable of
generating heat at a relatively low temperature.
Another object of the present invention is to provide a heating element in which a heating film can be firmly attached to a surface of a frame for a long time.
A further object of the present invention is to provide a fluid heating apparatus using a heating element capable of achieving the above objects.
Technical Solution
According to an aspect of the present invention for achieving the objects, there is provided a heating element comprise a frame made of a quartz or ceramic component; a heating film deposited on an outer surface of the frame in the form of a coating film and made of metal composition containing tin as a main component; and electrode bands formed at both ends of the heating element and connected to an external power source.
The heating film is formed through vapor deposition of metal composition, which comprises: 30 to 50 weight % of stannic chloride (SnCl 4 ); 2 to 5 weight % of antimony chloride (SbCl 3 ); 0.5 to 2 weight % of boric acid (H 3 BO 3 ); 0.1 to 1 weight % of ferric chloride (FeCl 3 ); and an ethanol solvent.
The frame is any one selected from the group consisting of a quartz tube, a ceramic tube, and a porcelain enamel tube.
The heating film has a power density range of 0.25 to 1.00 W/cm 2 . The frame has a sectional shape selected from the group consisting of circle, ellipse, triangle, quadrangle, pentagon and hexagon.
The frame has upper and lower ends with different diameters. The frame is a circular rod.
The electrode band is formed of an adhesive which comprises 10 weight % of silica, 60 weight % of silver and 30 weight % of pine resin.
The number of electrode bands varies from two to three depending on a length of the frame and a required amount of heat.
According to other aspect of the present invention for achieving the objects, there is provided a fluid heating apparatus comprise a heating element according to any one of claims 1 to 6, 8 and 9, through which fluid flows; and an assembling fixture coupled to
both ends of the heating element and formed with a fluid passage therein to communicate with the interior of the heating element such that the fluid flows through the fluid passage and the interior of the heating element.
The metal electrode rings are coupled around the electrode bands of the heating element to supply electric power to the heating film.
The assembling fixtures are provided in pair, and each of the assembling fixtures includes a thread for allowing the end of the heating element to be fitted therein, a connection port which communicates with the fluid passage and is formed in an inner side of the assembling fixture facing each other, and a fluid inlet or outlet hole for the fluid formed at an opposite outer side of the assembling fixture.
The heating element and the assembling fixture are coupled to each other by means of a heat-resistant gasket which surrounds both ends of the heating element and is fitted into a connection port to hermetically seal a coupling portion between the heating element and the assembling fixture, and a flange joint which is positioned on the heat- resistant gasket and is engaged with a thread formed in the connection port of the assembling fixture when an end of the heating element is inserted therein.
The heating element and the assembling fixture are coupled to each other using fixing bolts which pass through a plurality of fixing holes formed in an outer periphery of the assembling fixture and are engaged with nuts. The fluid passage of the assembling fixture is configured to connect inner passages of the heating elements in series with each other.
The fluid passage of the assembling fixture is configured to connect inner passages of the heating elements in parallel with each other.
The electrode bands of the heating element are formed by causing adhesives to be coated on the heating film at both ends and the middle of the heating film.
Advantageous Effects
As described above, the following advantages can be expected from the present invention. In the present invention, a nano-powder composite material containing tin as a
main component is deposited on a surface of a frame made of a material with good thermal conductivity through the nano vapor deposition to make a heating film by which heat can be generated at a relatively low temperature. That is, since the heating film generates heat but does not emit light at about 600°C, there is an advantage in that energy efficiency of the heating film is relatively enhanced.
Since the heating element of the present invention generates heat at a relatively lower temperature as described above, the heating film is not damaged at a high temperature and it can be thus securely attached to a surface of a frame for a longer period of time. Therefore, there is another advantage in that durability of the heating element or the fluid heating apparatus can also be improved.
Furthermore, the fluid heating apparatus of the present invention is configured in such a manner that a hollow heating element is connected thereto using an assembling fixture to allow fluid to flow through a fluid passage formed in the assembling fixture and the interior of the heating element so that the fluid can be directly heated. Thus, there a further advantage in that fluid can be rapidly heated.
Brief Description of Drawings
FIG. 1 is a perspective view of a heating element according to the present invention. FIG. 2 is a sectional view taken along line A-A of FIG. 1.
FIG. 3 is a perspective view of a fluid heating apparatus in which heating elements each formed with two electrode bands are assembled to a fixture according to a first embodiment of the present invention.
FIG. 4 is a sectional view taken along line B-B of FIG. 3, illustrating a state where showing that the heating elements are connected in series.
FIG. 5 is a sectional view taken along line B-B of FIG. 3, illustrating a state where the heating elements are connected in parallel.
FIG. 6 is a sectional view taken along line C-C of FIG. 3. FIG. 7 is a partial enlarged view showing an "A" portion of FIG. 6. FIG. 8 is a perspective view of a fluid heating apparatus in which heating
elements each formed with three electrode bands are assembled to a fixture according to a second embodiment of the present invention.
FIG. 9 is an exploded perspective view of FIG. 8.
FIG. 10 is a cross-sectional view illustrating that the heating element of the present invention has a sectional shape such as circle, ellipse and polygon such as triangle, quadrangle, pentagon and hexagon.
FIG. 11 is a perspective view illustrating that a circular rod is used as a frame constituting the heating element according to the present invention.
FIG. 12 is a perspective view illustrating that the heating element of the present invention has upper and lower ends with different diameters.
Best Mode
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. As shown in FIGS. 1 and 2, a frame 1 is formed into a basic structure of a heating element 4 and is made of a quartz or ceramic component. The frame 1 is a good heating element, and a heating film 2 is formed on an outer surface of the frame. The heating film 2 is deposited on the outer surface of the frame 1 in the form of a coating film and is made of a metal composition containing tin as a main component. The heating film 2 has a power density range of 0.25 to 1.00 W/cm 2 .
In the present invention, the heating film 2 is preferably formed through the vapor deposition of a metal composition, which comprises 30 to 50 weight % of stannic chloride (SnCl 4 ), 2 to 5 weight % of antimony chloride (SbCl 3 ), 0.5 to 2 weight % of boric acid (H 3 BO 3 ), 0.1 to 1 weight % of ferric chloride (FeCl 3 ), and ethanol solvent. In the present invention, the stannic chloride (SnCl 4 ) is converted into tin oxide
(SnO 2 ) in the process of the vapor deposition to perform a function of generating heat by resistance when electricity is supplied thereto. An amount of heat generated is decreased as a content of stannic chloride (SnCl 4 ) is lower, whereas an amount of heat generated is increased as the content is higher. Generally, if a content of stannic chloride is less than 30 weight %, an amount of heat generated is too low to be used for a
certain purpose. On the contrary, if the content is greater than 50 weight %, an amount of heat generated is larger but does not increase in proportion to the increase of content.
In the present invention, the antimony chloride (SbCl 3 ) functions as a binder for allowing tin oxide (SnO 2 ) to be easily combined with the frame 1 and also as a heating assistant. The antimony chloride (SbCl 3 ) has a weak binder function if its content is less than 2 weight %, whereas the antimony chloride cannot perform the binder function if its content is larger than 5 weight %.
In the present invention, the boric acid (H 3 BO 3 ) serves to allow molecules of the respective components to be well combined with one another and also allow the tin oxide to be uniformly distributed. If a content of boric acid (H 3 BO 3 ) is less than 0.5 weight %, the boric acid cannot well function as a binder and to uniformly form a film. On the contrary, if the content is larger than 2 weight %, it is undesirable in that the above function is not enhanced in proportion to the increase of content.
In the present invention, the ferric chloride (FeCl 3 ) is added to improve durability of a product. If a content of ferric chloride (FeCl 3 ) is less than 0.1 weight %, the product durability is not improved. On the contrary, if the content is larger than 1 weight %, it is undesirable in that the above function is not improved in proportion to the increase of content.
In the present invention, the metal chlorides are put into an ethanol solvent and then dissolved therein to be a metal chloride solution. The ethanol solvent dissolves the metal chlorides, but glycerin may be added as an assistant solvent and pure water may also be further added. If a content of glycerin serving as an assistant solvent exceeds 20 % by weight of the ethanol solvent, it may have adverse influence on solubility of the ethanol solvent. Thus, it is preferred that the glycerin be used within a range of less than 20 % by weight of the ethanol solvent. Further, even in a case where pure water is added as an assistant solvent, it is preferred that a content of pure water do not exceed 60 % by weight of the ethanol solvent. If the pure water acting as an assistant solvent exceeds 60 % by weight of the ethanol solvent, a content of an ethanol component is relatively lowered. Therefore, efficient and uniform dissolution of metal chlorides may be hindered.
In consideration of the durability and quality stability of products, additives may be put into the metal chloride solution.
In order to fabricate the heating element 4 according to the present invention, 100 parts of ethanol (C 2 H 5 OH) serving as a solvent and 100 parts of stannic chloride (SnCl 4 ) serving as a main component are first mixed in a mixing vessel, and then, 50 parts of pure water (H 2 O) are basically mixed for dilution. Then, the respective metal chlorides are put into and mixed with 250 parts of the above mixture, and a metal chloride solution is obtained. If required, glycerin may be added together with the ethanol and pure water in order to further enhance solubility of the mixture. In the present invention, the heating film 2 is preferably formed by coating an outer surface of the frame 1 with metal chloride. To this end, a coating layer of the metal chloride may be formed on the surface of the frame 1 at a predetermined thickness and then allowed to react at a high temperature such that the layer can be converted into the heating film 2. More preferably, in consideration of working efficiency and product uniformity, the metal chloride solution is vapor deposited on the frame to form the heating film 2 within a high temperature furnace.
In the present invention, the vapor deposition of the metal chloride solution is performed as follows. First, the metal chloride solution is put into an evaporation vessel made of a ceramic material and the evaporation vessel is then placed on a heating unit of a furnace. The furnace is gradually heated in a state where the frame 1 is placed above the evaporation vessel. At this time, the evaporation vessel is controlled to be within a temperature range of 200 to 300°C, while a region where the frame 1 is placed is controlled to be kept at a temperature of 600 to 900 0 C. If the furnace is heated with a temperature difference as described above, moisture in the metal chloride solution is evaporated and at the same time reacted with metal chloride, and the reactants, i.e. metal oxide components free of chlorine components, are deposited on the surface of the frame 1 placed above the evaporation vessel. The heating film 2 obtained by depositing the metal composition onto the surface of the frame 1 as described above is not aged even in a case where heat is generated for a long time at a high temperature of 600°C or more. Further, the frame 1 and the heating film 2 are not separated from each other, and heat is
generated in a state where no light is emitted. Therefore, energy conversion efficiency can be greatly improved.
The frame 1 for use in the present invention is formed of a quartz tube, a ceramic tube or a porcelain enameled tube which is made of a good insulation material and has no substantial possibility of breakage or electric leakage due to a small expansion coefficient when rapidly heated or cooled between 2O 0 C and l,000°C.
When a composite material is deposited to form the heating film 2 on the outer surface of the tube 1 , both ends of the frame 1 should be masked by approximately 2 cm to 5 cm such that the heating film 2 is not formed thereon. Adhesives formed by mixing 10 weight % of silica, 60 weight % of silver and 30 weight % of pine resin are coated at wither both ends of the heating film 2 or both ends and the middle of the heating film 2 to form electrode bands 3, around which in turn electrode rings 7 are fixed such that a power source is connected to supply an electric current to the electrode rings. As shown in FIGS. 3 to 7, the electrode rings 7 are installed to each of the heating elements 4 formed with the heating film 2 and the electrode bands 3 to surround the electrode bands 3, and then, a flange joint 5 and a gasket 6 are sequentially coupled to both ends of the heating element 4 such that both ends of the heating element 4 are inserted into a plurality of connection ports 8 of an assembling fixture 9. At this time, each of the heating elements 4 is hermetically coupled to the assembling fixture 9 by means of the gasket 6 and the flange joint 5.
After a plurality of the heating elements 4 have been coupled to the assembling fixture 9 in this way, fixing bolts 10 pass through fixing holes 15 formed in the assembling fixture 9 and then fastened with nuts 14 such that the heating elements 4 and the assembling fixture 9 are securely coupled with each other. The assembling fixture
9 is formed with a fluid passage 12 therein and is also formed with inlet/outlet connection ports 11 and 13 for the connection with a pipe.
The assembling fixture 9 or 9a is made of metal or a non-metal material. The assembling fixture 9 or 9a is formed with connection ports 8 in which the heating elements 4 are connected and fixed. The heating elements 4 may be connected either in
series as shown in FIG. 4 or in parallel as shown in FIG. 5. The number of connection ports 8 may be increased over one, if necessary.
A diameter of the connection port 8 of the assembling fixture 9 or 9a should be greater than that of the heating element 4, and the connection port 8 is divided into a portion in which the heating element 4 is inserted, a portion in which the gasket 6 is fitted, and a portion to which the flange joint 5 is screwed. The flange joint 5 should have an inner diameter greater than an outer diameter of the heating element 4 and a thickness of 1 mm or more. Since the assembling fixture 9 or 9a should be normally operated even at an inner pressure of 12 Pa (in gauge pressure), the fluid passage 12 or 12a should also be manufactured to have a wall thickness capable of withstanding 12 Pa (in gauge pressure).
The fluid heating apparatus 20 so configured is operated in such a manner that if a current is applied to the electrode ring 7 installed to the heating element 4, the current flows from the electrode band 3 at one side on the heating element 4 to the electrode band 3 at the other side thereof. As a result, thermal energy is generated from the heating film 2 placed between the electrode ring and the electrode band to emit the heat. The thermal energy released from the heating film 2 is absorbed into a fluid circulating in the heating element 4 so that the fluid can be rapidly heated.
The heated fluid circulates through a circulating pipe of an electric boiler which is connected with the inlet/outlet connection ports 11 and 13 protruding from the assembling fixture 9.
The present invention may be employed mainly in a heating device such as a boiler, a heater and a fan heater, and it may also be widely used in industrial fields such as various industrial heating devices and agricultural product drying devices. Furthermore, FIGS. 8 and 9 show a fluid heating device 20 according to another embodiment of the present invention in which three electrode bands 3 are formed on a heating film 2 of a heating element 4a. The number of electrode bands 3 may be adjusted to two or three, depending on the length of the heating element.
Further, FIG. 10 shows that the heating element 4 or 4a formed with the heating film 2 thereon may have a section whose shape is circular, elliptical or polygonal such as
triangular, quadrangular, pentagonal and hexagonal.
FIG. 11 shows that a circular rod is used as a frame constituting a heating element according to the present invention. In such a case, heat generated from the heating film 2 is not transferred to fluid flowing through the interior of the heating element 4b but to fluid residing around the heating element 4b. FIG. 12 shows that the heating element of the present invention has upper and lower ends with different diameters. That is, a section of the frame may be selectively employed depending on the field of application of the fluid heating apparatus.
As described above, the present invention is not limited to the aforementioned preferred embodiments, but various modifications can be made within the scope of the invention defined in the appended claims without departing from the spirit of the invention by those having ordinary skill in the art.
For example, although it has been illustrated in the illustrated embodiments that the assembling fixtures 9 are fixed to each other using the fixing bolts 10, the present invention is not necessarily limited thereto. If the assembling fixture 9 and the heating element 4 can be fixed to each other when they are coupled, the additional fixing bolts 10 are not required. Further, it is not always necessary that the assembling fixture 9 and the heating element 4 are coupled in such a way as shown in the accompanying drawings.
Meanwhile, in a case of a structure in which heat generated from the heating film 2 of the heating element 4 is transferred to a fluid passing through the interior of the heating element 4, an outer portion of the heating element 4 is preferably formed of a material having excellent insulating property to prevent the heat from being released to the outside.
Industrial Applicability
According to the present invention, heat generated from a heating film of the heating element is transferred to a fluid passing through the heating element such that the fluid can be heated to a desired temperature. Therefore, the present invention can be employed in a variety of applications.