Abstract:
Provided is a fluid heating device that is small in size and capable of heating a large flow of gas or liquid at a low cost. A flow path in which no backwater is produced is provided by providing grooved flow paths of a fluid are provided over an outer side surface of a metallic circular cylinder such that a fluid passing through a narrowed one of the flow paths impinges perpendicularly against a wall of the next flow path. This allows instantaneous heat exchange within a small space, and makes manufacturing of such a structure simple.

Description:
This application is based on and claims the benefit of propriety from Japanese Patent Application No. 2012-107128, filed on May 8, 2012, the content and teachings of which are incorporated by reference herein their entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a cylindrically shaped device capable of instantaneously heating a fluid, in particular, a gas. 
     2. Description of the Related Art 
     There is known a device for heating a gas. Typically, this device heats a gas by letting the gas to pass through a heated pipe. Alternatively, this device heats a gas by causing a heated fluid to flow through a pipe having fins and letting the gas to pass between the fins. 
     A device for cooling a gas, opposite of heating, is configured in the same manner. 
     Conventional examples of such a device are illustrated in  FIG. 1  and  FIG. 2 . 
       FIG. 1  is a copy of a drawing schematically illustrating an exemplary patent that realizes a heating mechanism called an impinging jet (WO 2006/030526). A gas that has passed a pipe impinges against a heated circular disk and exchanges heat. 
       FIG. 2  is a copy of a drawing illustrating a patent for a plate-shaped device for producing a heated gas (FIG. 5 of Japanese Patent Application No. 2009-144807, “Gas Heating Apparatus”). 
     Applications of a device for instantaneously heating a gas and ejecting a hot gas include steps of heating and firing various materials (such as a metal and a dielectric material) applied on a substrate, in addition to air heating and drying. 
     The present invention relates to a device for instantaneously heating a gas and ejecting a hot gas. 
     Accordingly, an object of the present invention is to downsize a device for heating a gas as much as possible. Another object of the present invention is to provide a simplified manufacturing method. 
     Yet another object of the present invention is to realize a range of heating temperatures from room temperature to 1000 degrees Celsius or above. By simplifying the processing, it is possible to reduce a manufacturing cost. The reduced cost allows the gas heating device to be applicable to a wide range of industries. 
     SUMMARY OF THE INVENTION 
     For purposes of summarizing the invention, certain aspects of the invention have been described herein. It is to be expressly understood that it is not intended as a definition of the limits of the invention. 
     In order to solve the aforementioned problems, the present invention proposes the following arrangements. 
     A first aspect of the present invention provides a fluid heating device provided with: an inner cylinder having a plurality of annular grooves provided around an outer side surface of the inner cylinder and a plurality of sets of connecting grooves provided on the outer side surface, each set of connecting grooves connecting two of the annular grooves, circumferential positions of connecting grooves in two of the sets of connecting grooves provided on respective sides of one of the annular grooves are displaced from each other; and a cylinder containing the inner cylinder in close contact with each other, wherein a fluid flows through a flow path defined by an inner wall of the cylinder and the outer side surface of the inner cylinder, and whereby heat is exchanged between the fluid and the flow path. 
     A second aspect of the present invention provides a heating device provided with: an inner cylinder having a plurality of annular grooves provided around an outer side surface of the inner cylinder and a plurality of sets of connecting grooves provided on the outer side surface, each set of connecting grooves connecting two of the annular grooves, circumferential positions of connecting grooves in two of the sets of connecting grooves provided on respective sides of one of the annular grooves are displaced from each other; and a cylinder containing the inner cylinder in close contact with each other, wherein one of a gas and a liquid flows through a flow path defined by an inner wall of the cylinder and the outer side surface of the inner cylinder, and whereby heat is exchanged between the one of the gas and the liquid and the flow path. 
     A third aspect of the present invention provides the heating device according to the second aspect, wherein the gas is one of an inert gas, a reductive gas, a gas containing a Group 6 element, a gas containing a Group 7 element, and a combination of two or more of these gases, examples of the inert gas including nitrogen, argon, helium, carbon hydride, and carbon fluoride, the reductive gas being one of hydrogen and a gas releasing hydrogen, examples of the gas containing a Group 6 element including oxygen, sulfur, selenium, and tellurium, examples of the gas containing a Group 7 element including fluorine. 
     A fourth aspect of the present invention provides the heating device according to the second aspect, wherein the gas contains one of water and air. 
     A fifth aspect of the present invention provides the heating device according to the second aspect, wherein the liquid is one of water and a liquid containing water. 
     A sixth aspect of the present invention provides the heating device according to the first aspect, wherein each of the cylinder and the inner cylinder is configured by one of a metal and a metal coated by a different kind of metal. 
     A seventh aspect of the present invention provides the heating device according to the first aspect, wherein each of the cylinder and the inner cylinder is configured by ceramic, examples of a material of the ceramic including quartz, alumina, and silicon carbide. 
     An eighth aspect of the present invention provides the heating device according to the first aspect, wherein each of the cylinder and the inner cylinder is configured by one of a metal and a metal coated by a different kind of metal, and a heater inserted into the inner cylinder heats one of a circular column and the cylinder. 
     A ninth aspect of the present invention provides the heating device according to the first aspect, wherein each of the cylinder and the inner cylinder is configured by ceramic, examples of a material of the ceramic including quartz, alumina, and silicon carbide, and a heater inserted into the inner cylinder heats one of a circular column and the cylinder. 
     A tenth aspect of the present invention provides the heating device according to the first aspect, wherein the inner cylinder is configured as one of a circular cylinder and a polygonal cylinder including a rectangular cylinder. 
     An eleventh aspect of the present invention provides the heating device according to the first aspect, wherein each of the cylinder and the inner cylinder is configured by one of a metal and a metal coated by a different kind of metal, and the inner cylinder is configured as one of a circular cylinder and a polygonal cylinder including a rectangular cylinder. 
     A twelfth aspect of the present invention provides the heating device according to the first aspect, wherein each of the cylinder and the inner cylinder is configured by ceramic, examples of a material of the ceramic including quartz, alumina, and silicon carbide, and the inner cylinder is configured as one of a circular cylinder and a polygonal cylinder including a rectangular cylinder. 
     According to the first aspect of the present invention, it is possible to perform heat exchange between the inner cylinder contained within the heated cylinder of a simple structure and the fluid. Processing for this structure is only required to a surface of the inner cylinder. 
     When the fluid flows through the connecting grooves that are made to be narrow, a velocity of the fluid increases. This high-speed fluid impinges furiously against the wall of the annular groove, and heat is exchanged instantaneously with the heated inner cylinder. 
     As the circumferential positions of the connecting grooves on either side of an annular groove are not the same, the fluid that has exited from the connecting groove does not form a laminar flow. Formation of a laminar flow results in a stagnant backwater between the groove and the fluid and provides a resistance of the heat transfer, and whereby instantaneous heat exchange is prevented. 
     The cylinder and the inner cylinder having the processed grooves allows the processed grooves to constitute the flow path only by containing the inner cylinder that have been accurately processed within the cylinder in close contact with each other, and therefore such a structure can be easily manufactured with a reduced number of steps. 
     According to the second to the fifth aspect of the present invention, a gas or a liquid can be used as the fluid. As the gas, any gas can be freely selected. When oxygen and such are selected, it is possible to instantaneously produce heated oxygen. When hydrogen is selected, it is possible to instantaneously produce a strong hot reductive gas. By spraying the hot gas to a base material, it is possible to perform a surface treatment of the base material by a heated gas without heating the base material itself. Alternatively, when using a carbon dioxide gas, it is possible to provide a carbon dioxide film (a graphene or carbon nanotube film). 
     When using water as the fluid, it is possible to instantaneously produce a high-temperature steam. This heating device can be manufactured small in size, and therefore it is possible to spray the steam while bringing the heating device is closer to a base material to be sprayed. 
     As the heated high-temperature steam is effective for cleaning a base material without using chemicals, this heating device is applicable as a component of a cleaning device. 
     According to the sixth and the seventh aspect of the present invention, this heating device can be made of either a metal or ceramic. Manufacturing the inner cylinder and the cylinder of a metal and welding a connecting section therebetween allow a hermetic structure, and therefore it is possible to manufacture a heating device shielded from an external environment. 
     When using a material that does not become oxidized such as ceramic, it is possible to instantaneously heat an oxidized gas or a corrosive fluid. In addition, it is possible to use this heating device in the application in which avoidance of metal contamination is required. 
     According to the eighth to the twelfth aspect of the present invention, it is possible to perform the heating only by providing a hole along a central axis of the inner cylinder and inserting a heater in this hole. This configuration is simple and provides simple maintenance when only one heater is used. The heating device as a whole can be manufactured in a circularly or polygonally cylindrical shape, and with this, it is possible to produce a heated gas beam in a shape of circular or quadrangular ring. By narrowing the outlet of the cylinder to form a single tube, it is possible to produce a single heated beam in a shape of beam. Further, when the inner cylinder is formed in a shape such as triangular, quadrangular, hexagonal, or octagonal, it is possible to combine more than one inner cylinder without any gap. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of one example of a conventional gas heating device (WO 2006/030526); 
         FIG. 2  is a schematic view of another example of the conventional gas heating device (FIG. 5 of Japanese Patent Application No. 2009-144807, “Gas Heating Apparatus”); 
         FIG. 3  is a schematic view of an inner cylinder unit; 
         FIG. 4  is a perspective view of a fluid heating mechanism in which the inner cylinder unit and a cylinder unit for containing the inner cylinder unit are incorporated; and 
         FIG. 5  is a schematic cross-sectional view of a fluid heating device representing an entire case containing the fluid heating mechanism. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Description will be made below regarding embodiments of the present invention with reference to the drawings. It should be noted that each of the components of the following embodiments can be replaced by a different known component or the like as appropriate. Also, any kind of variation may be made including a combination with other known components. That is to say, the following embodiments described below do not intend to limit the content of the present invention described in the appended claims. 
       FIG. 3  shows a schematic cubic diagram of an inner cylinder unit  300 . In a center of the inner cylinder unit  300 , a heater hole  301  for containing a heater is provided. 
     The inner cylinder unit  300  is made of SUS310S stainless steel. A circular cylinder is processed such that six annular grooves G 1 , G 2 , G 3 , G 4 , G 5 , and G 6  are provided therearound. A depth and a width of these annular grooves are 3 mm and 5 mm, respectively. Then, four connecting grooves C 1 A connecting the annular grooves G 1  and G 2  are provided. In the reference symbol C 1 A, “1” indicates that these connecting grooves are connected to the annular groove G 1 , and “A” represents a phase specifying circumferential positions of these connecting grooves. 
     A depth and a width of these connecting grooves C 1 A are 3 mm and 1 mm, respectively. 
     In the same manner, four connecting grooves C 2 B connecting the annular grooves G 2  and G 3  are provided. In the reference symbol C 2 B, “2” indicates that these connecting grooves are connected to the annular groove G 2 , and “B” represents a phase specifying circumferential positions of these connecting grooves. 
     The phase B corresponds to a midpoint of the phase A along the circumference. The relation between the phases can be freely designed. In this case, as there are four connecting grooves along the circumference, the phase A and the phase B are displaced from each other by 45 degrees. If the number of connecting grooves provided along the circumference is six, the displacement is 30 degrees. 
     In the same manner, connecting grooves C 3 A, C 4 B, C 5 A, and C 6 B are provided. 
     A fluid inlet tube  302  is welded, and a fluid introduced into this inlet tube is directed to the annular groove G 1 . 
     The inner cylinder unit  300  provided with the heater hole  301 , the annular grooves G 1 -G 6 , and the connecting grooves C 1 A, C 2 B, C 3 A, C 4 B, C 5 A, and C 6 B is contained within a cylinder. 
       FIG. 4  is a perspective view of a fluid heating mechanism  400  in which the inner cylinder unit  300  and a cylinder unit for containing the inner cylinder unit  300  are incorporated. 
     The inner cylinder unit  300  is in close contact with an inner wall of the cylinder unit  401 . A connected section therebetween is welded so as to prevent a fluid from leaking. 
     A fluid pressurized and introduced through the fluid inlet tube  302  passes through the annular grooves, and becomes a high-speed fluid when passing through the connecting grooves. The high-speed fluid impinges against a wall of the annular groove perpendicularly at a high speed. By impinging perpendicularly, a stagnant backwater as a resistance of heat transfer may not be produced. 
     The inner cylinder unit  300  is heated by a heater  403  that is fed from a heater power feeder  402 . The heater is made of silicon carbide, and capable of heating at 1000 degrees Celsius. 
     The cylinder unit  401  and the inner cylinder unit  300  are made of SUS310S, and therefore can be heated up to 1000 degrees Celsius. 
       FIG. 5  is a schematic cross-sectional view of a fluid heating device representing an entire case containing the fluid heating mechanism  400 . 
     A fluid heating device  500  is configured by containing the fluid heating mechanism  400  within an insulator case. The fluid heating mechanism  400  is insulated by an insulator case  502  containing an insulator  501 . 
     Outside the insulator case  502 , a stainless-steel external case  503  is provided, and an end of the external case  503  is connected to a flange  504 . 
     The inner cylinder unit is heated by the heater  403  that is fed from the heater power feeder  402 . The temperature of the inner cylinder unit is measured by a thermocouple that is not depicted, and the electric power is controlled so as to maintain the measured temperature. Here, in order to produce heated nitrogen at 500 degrees Celsius, the electric power is fed so as to be able to maintain the temperature at 500 degrees Celsius. 
     A nitrogen gas of 100 SLM is supplied through a gas inlet tube  505 . The nitrogen gas flows through an annular groove  506  and the connecting grooves that are not visible in this figure, and is instantaneously heated within the fluid heating mechanism  400 . 
     The nitrogen heated up to 500 degrees Celsius exits through a gas outlet tube  507 . 
     If the heating temperature is controlled at 300 degrees Celsius, it is possible to obtain nitrogen at 300 degrees Celsius. 
     In the above, an example in which a nitrogen gas is heated has been described. However, a gas other than the nitrogen gas can be freely used in this heating mechanism. 
     It is possible to use any of an inert gas examples of which including argon, helium, carbon hydride, and carbon fluoride, hydrogen and a reductive gas releasing hydrogen, a gas containing a Group 6 element examples of which including oxygen, sulfur, selenium, and tellurium, and a gas containing a Group 7 element examples of which including fluorine. Alternatively, it is possible to use a combination of two or more of these gases. In addition, when carbon hydride is used, carbon hydride is dissolved and a film such as a graphene film can be formed. 
     Further, the gas can contain one of water and air. 
     It is also possible to freely use a fluid other than the gas. For example, when water is used as the fluid, it is possible to produce a high-temperature steam. 
     In the above embodiment, the cylinder and the inner cylinder unit are made of SUS310S. However, it is possible to freely select a suitable material according to a temperature range to be used and characteristics of the fluid to be used. A material that constitutes the components can be a metal such as stainless and aluminum, as well as a metal coated by a different kind of metal. 
     Further, in an application in which avoidance of metal contamination is in particular required, the inner cylinder unit and the cylinder can be made of ceramic including such as quartz, alumina, and silicon carbide. 
     The present invention provides a downsized component capable of producing a large flow of hot gas or liquid, and can be used in application fields such as drying of printed materials, small-sized heating appliances, air heating in glass houses, and producing a high-temperature medical agent for cleaning. The present invention is also suitable for a technique of film formation of such as a solar cell or a flat-panel display device (FPD) on a large-sized substrate such as a glass substrate at a low cost. Further, it is possible to obtain a degradation film when a gas that can be pyrolyzed is used. Moreover, it is possible to obtain a carbon film from carbon hydride. 
     While preferred embodiments of the invention have been described and illustrated above, it should be noted that these are example embodiments of the invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims. 
     DESCRIPTION OF THE REFERENCE NUMERALS 
     
         
         
           
               101  Gas Inlet 
               102  Hollow Disk 
               103  Pipe 
               104  Gas Outlet 
               300  Inner Cylinder Unit 
               301  Heater Hole 
               302  Fluid Inlet Tube 
             C 1 A, C 2 B, C 3 A, C 4 B, C 5 A, C 6 B Connecting Grooves 
             G 1 , G 2 , G 3 , G 4 , G 5 , G 6  Annular Grooves 
               400  Fluid Heating Mechanism 
               401  Cylinder Unit 
               402  Heater Power Feeder 
               403  Heater 
               500  Fluid Heating Device 
               501  Insulator 
               502  Insulator Case 
               503  External Case 
               504  Flange 
               505  Gas Inlet Tube 
               506  Annular Groove 
               507  Gas Outlet Tube