Patent Publication Number: US-2009223076-A1

Title: Heating, Sterilizing and Drying Appliance Using Superheated Steam Generator

Description:
TECHNICAL FIELD 
     The present invention relates to a heating, sterilizing and drying appliance using a superheated steam generator, which uses, as a heat source, superheated steam produced from the superheated steam generator, and more particularly, to such a heating, sterilizing and drying appliance which reduces a manufacturing cost by simplifying the structure of the superheated steam generator, minimizes the size of steam molecules to produce high-temperature steam which is easy to permeate into a to-be heated material to maximize a temperature-raising effect. 
     BACKGROUND ART 
     In general, a superheated steam generator refers to a device which heats saturated steam supplied from a boiler and so forth so as to produce a large quantity of superheated steam during a short time period. The superheated steam produced by the superheated steam generator is used as a heat source of food cooking equipment, sterilizer equipment or drier equipment, since it is made of relatively high-temperature, fine particles as compared to the saturated steam. 
     For instance, the cooking equipment using the superheated steam has a merit that it is characterized by uniformly heating food so that the food is not burnt locally and the temperature and the supply amount of the superheated steam are easily adjusted to readily control the cooking characteristic, as well as oxidation due to the steam is prevented to allow the original flavor to be maintained. 
     However, the conventional superheated steam generator entails demerits in that since it has a plurality of complicated constituent parts including a screw-type heat transfer tubes embedded therein so as to secure a fluid-passing cross-section required for generating and treating the superheated steam, a manufacturing cost increases, which leads to an increase in maintenance and repair costs of products. 
     Furthermore, the conventional superheated steam generator encounters a problem in that it is difficult to obtain superheated steam having a uniform temperature since a deviation of steam flow rate is large due to a complexity of built-in components. Moreover, if local overheat occurs in the heat transfer tube itself due to the deviation of fluid flow rate, there is caused another problem in that the built-in components are deteriorated to thereby degrade their durability. 
     DISCLOSURE OF INVENTION 
     Technical Problem 
     Accordingly, the present invention has been made to address and solve the above-mentioned problems occurring in the prior art, it is an object of the present invention to provide a heating, sterilizing and drying appliance using a superheated steam generator, which reduces a manufacturing cost by simplifying the structure of the superheated steam generator, minimizes the size of steam molecules to produce high-temperature steam which is easy to permeate into a to-be heated material to maximize a temperature-raising effect. 
     Technical Solution 
     To accomplish the above object, according to one aspect of the present invention, there is provided a heating appliance using a superheated steam generator, comprising: a saturated steam distributor adapted to selectively distribute saturated steam which is produced by a boiler and then is separated from condensed water while passing through a separator in the process of opening a valve assembly; a superheated steam generator adapted to allow streams of the steam supplied thereto from the saturated steam distributor to generate vortices while passing through a plurality of disc-like interval-maintaining means stackingly arranged on top of one another longitudinally in a combustion chamber thereof and adapted to heat the vortex-generating steam through a plurality of superheated steam heating means penetratingly mounted vertically in the plurality of interval-maintaining means to thereby produce superheated steam; and a superheated steam supply line adapted to inject the superheated steam which is produced by the superheated steam generator and is discharged after passing through the combustion chamber toward a heating place through a superheated steam injection line. 
     ADVANTAGEOUS EFFECTS 
     According to the heating, sterilizing and drying appliance using a superheated steam of the present invention, the saturated steams supplied to the superheated steam generator is heated while generating vortices by the unique construction of the superheated steam generator so that they are decomposed to small-sized molecules (clusters) to thereby improve the temperature efficiency of the superheated steam. 
     Further, the time and cost spent for generating the superheated steam is minimized, and the inner construction of the superheated steam generator is simplified to thereby reduce various expenses according to manufacture, maintenance and repair. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a conceptual view illustrating a heating, sterilizing and drying appliance using a superheated steam generator according to the present invention; 
         FIG. 2  is a top exploded perspective view illustrating the superheated steam generator according to the present invention; 
         FIG. 3  is a cross-sectional view illustrating the superheated steam generator according to the present invention in an assembled state; 
         FIGS. 4(   a ) and  4 ( b ) are cross-sectional views illustrating a heating element of the superheated steam generator according to the present invention; and 
         FIG. 5  is a cross-sectional view illustrating a superheated steam injection line of a superheated steam supply line according to the present invention. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Reference will now be made in detail to the preferred embodiment of the present invention with reference to the attached drawings. 
       FIG. 1  is a conceptual view illustrating a heating, sterilizing and drying appliance using a superheated steam generator according to the present invention in a disassembled state,  FIGS. 2 and 3  are top exploded perspective and cross-sectional views illustrating the superheated steam generator according to the present invention,  FIGS. 4(   a ) and  4 ( b ) are cross-sectional views illustrating a heating element of the superheated steam generator according to the present invention, and  FIG. 5  is a cross-sectional view illustrating a superheated steam injection line of a superheated steam supply line according to the present invention. 
     The heating, sterilizing and drying appliance using a superheated steam generator according to the present invention includes: a saturated steam distributor  10  adapted to selectively distribute saturated steam which is produced by a boiler  11  and then is separated from condensed water while passing through a separator  12  in the process of opening a valve assembly  13 ; a superheated steam generator  20  adapted to allow streams of the steam supplied thereto from the saturated steam distributor  10  to generate vortices while passing through a plurality of disc-like interval-maintaining member  23  stackingly arranged on top of one another longitudinally in a combustion chamber  21  thereof and adapted to heat the vortex-generating steam through a plurality of superheated steam heating elements  22  penetratingly mounted vertically in the plurality of interval-maintaining members to thereby produce superheated steam; and a superheated steam supply line  30  adapted to inject the superheated steam which is produced by the superheated steam generator  20  and is discharged after passing through the combustion chamber  21  toward a heating place H through a superheated steam injection line  32 . 
     First, the appliance using a superheated steam generator according to the present invention is constructed of a structure such as a heating appliance, a sterilizing appliance and a drying appliance. Since the constituent elements such as the heating appliance, the sterilizing appliance and the drying appliance are identical to one another, they are denoted and described by using the same reference numerals. Specifically, the present invention will be described hereinafter while being limited to the heating appliance among all the appliances. 
     Here, the heating appliance  1  is constructed of a saturated steam distributor  10  for distributing saturated steam which is produced by a boiler  11 , a superheated steam generator  20  for heating the steam supplied thereto from the saturated steam distributor  10  to thereby produce superheated steam, a superheated steam supply line  30  for supplying the superheated steam which is produced by the superheated steam generator  20  to a use place (heating place), and a controller (not shown) for controlling the heating of the constituent elements. 
     The saturated steam distributor  10  includes a saturated steam supply line  15  connected to a boiler  11  so as to allow saturated steam produced from the boiler  11  to be supplied therethrough, a separator  12  mounted on a pipe path of the saturated steam supply line  15  so as to separate water and the saturated steam from each other, and a valve assembly  13  for adjusting the supply amount of the saturated steam separated by the separator  12 . 
     Also, on the saturated steam supply line  15  is mounted a drain tube  14  for discharging the condensed water and the residual saturated steam remained after being distributed by the valve assembly  13  and supplied to the superheated steam generator  20 . 
     In addition, on the saturated steam supply line  15  are mounted a pressure-reducing valve  16  for reducing a pressure of the saturated steam supplied from the boiler  11  to the pressure level needed by the superheated steam generator  20 , and a safety valve  17  for controlling the vapor pressure of the saturated steam to be introduced into the superheated steam generator  20  to be a prescribed pressure. 
     Further, the valve assembly  13  serves to adjust the amount of the saturated steam supplied from the boiler  11  for supply to the superheated steam generator  20 , and consists of first and second electronic valves  13   a  and  13   b  whose capacities are different from each other. The valve assembly  13  is configured such that the first electronic valve  13   a  and the second electronic valve  13   b  are opened/closed concurrently or separately in response to a control signal generated from a controller (not shown) so as to adjust the amount of the saturated steam to be introduced into the superheated steam generator  20 . 
     In addition, the superheated steam generator  20  has been invented by applying “a superheated steam generating device (Korean Application No. 10-2005-123156) which was filed prior to the filing of the present application by the applicant of the present invention. The superheated steam generator  20  includes a housing  27  formed with a combustion chamber  21  for therein accommodating the saturated steam selectively supplied by the valve assembly  13 , a plurality of disc-like interval-maintaining members  23  stackingly arranged on top of one another longitudinally in the combustion chamber  21  of the housing  27 , and a plurality of superheated steam heating elements  22  penetratingly mounted vertically in the plurality of disc-like interval-maintaining members  23  so as to produce superheated steam. 
     Also, the housing  27  has a discharge outlet  25  formed at a bottom end thereof so as to allow superheated steam to be discharged to the superheated steam supply line  30  therethrough, and a cover  24  is mounted on a top end of the combustion chamber  21  of the housing  27  and has an injection inlet  24   a  formed at a top end thereof to be connected to the saturated steam supply line  15  so as to allow the saturated steam to be injected into the combustion chamber  21  therethrough. 
     At this time, the housing  27  is preferably formed in a cylindrical or polygonal shape, and particularly is preferably made of a material excellent in corrosion resistance and heat resistance such as stainless steel, etc. 
     In addition, the cover  24  is preferably securely fixed to the top end portion of the combustion chamber  21  of the housing  27  by means of a fastening means such as a bolt or in a press-fitting manner. Specifically, the cover  24  has a plurality of throughholes  24   b  formed thereon for allowing the plurality of superheated steam heating elements  22  to be protruded upwardly therethrough, which will be described later. 
     The plural disc-like interval-maintaining members  23  are horizontally stackingly arranged on top of one another in the combustion chamber  21  of the housing  27  in such a fashion as to be spaced apart from one another by equal distances, so that the disc-like interval-maintaining members  23  allows the stream of the superheated steam to generate vortices and serves to support the superheated steam heating elements  22 . The disc-like interval-maintaining members  23 - 1  and  23 - 2  positioned in odd and even number rows are formed to be different from each other in outer diameters. 
     Also, the disc-like interval-maintaining members  23  allows a fluid-communicating passageway  26  to be defined in a gap between the inner wall of the combustion chamber  21  and the interval-maintaining members  23 - 1  of odd number rows, and at the central portion of the interval-maintaining members  23 - 2  of even number rows, respectively, so that the steam can passes therethrough while generating vortices. Of course, the fluid-communicating passageways  26  respectively formed in the disc-like interval-maintaining members  23 - 1  and  23 - 2  of even and odd number rows may be altered in position. 
     Also, the disc-like interval-maintaining members  23  can preferably be made of a material excellent in corrosion resistance and heat resistance such as stainless steel, etc., but it is natural that the interval-maintaining member  23  may be made of a ceramic material. Moreover, each of the disc-like interval-maintaining members  23  has a plurality of fitting holes  23   a  formed therein in such a fashion as to be arranged spaced apart from one another equidistantly at a peripheral portion of the disc-like interval-maintaining members so as to fixedly fit the superheated steam heating elements  22  thereto. 
     The superheated steam heating elements  22  are securely fit into the fitting holes  23   a  of the disc-like interval-maintaining members  23  by means of welding or press-fitting so as to heat steam which is supplied to the combustion chamber  21  and generates vortices while passing through the fluid-communicating passageways  26   
     Also, the superheated steam heating elements  22  includes stainless steel  22   b  or ceramic  22   c  coated on a hot wire  22   a  disposed at the central portion thereof, or the stainless steel  22   b  and ceramic  22   c  are sequentially coated on the hot wire  22   a  so as to protect the hot wire or emit a far-infrared ray. 
     At the heating place H is mounted a ceramic heater  33  made of a ceramic material for emitting a far-infrared ray with a high permeability so as to improve firing, a heating and drying speed in cooperation with the atomized superheated steam flow. 
     At this time, the ceramic heater  33  is of course used to prevent the condensation of the superheated steam injected through the superheated steam injection line  32  as well as adjust a heating temperature in the heating place H. Also, it is preferably mount an automatic temperature gauge  31   b  for measuring and adjusting the temperature of the ceramic heater  33  in the heating place H. 
     The superheated steam supply line  30  is configured such that the superheated steam produced by heating while vortices being generated by means of the interaction between the disc-like interval-maintaining members  23  and the superheated steam heating elements  22  is injected toward the heating place H using the superheated steam injection line  32 . It is preferable to mount an automatic temperature gauge  31   a  in the discharge outlet line of the superheated steam generator  20  so as to measure and adjust the temperature of the superheated steam. 
     In addition, the superheated steam injection line  32  is configured such that a plurality of conical holes are directly drilled in a row on the outer surface of a body of the superheated steam injection line or round screws each having an injection hole  32   a  formed centrally therein are uniformly arranged on the outer surface of the body of the superheated steam injection line in such a fashion as to be juxtaposedly disposed at both sides of the outer surface of the body of the superheated steam injection line at an injection angle of 30 degrees. 
     That is, the superheated steam injection line  32 , as shown in  FIG. 5 , has round screws made of stainless steel disposed at both sides of the outer surface of the body thereof. In this case, it is preferable to form conical injection holes  32   a  having an angle and length conforming to the round screws. 
     As a result, if the hole of the superheated steam injection line  32  is blocked off due to foreign substances, only the round screws used are removed to thereby facilitate their replacement with new ones. 
     At this time, examples of the heating place H employing the superheated steam produced by the superheated steam supply line  30  include a cooking appliance used for cooking foods such as, for example, pizza, etc., various heating appliances, a sterilizing and drying appliance, a carbonizing heat-treatment apparatus for drying general wastes, paints, wood materials and the like, etc. 
     The controller (not shown) is electrically connected to the saturated steam distributor  10 , the superheated steam generator  20  and the superheated steam supply line  30  so as to receive the pressure, the amount of the steam, the heating time and the temperature signal of the constituent parts to generate an operating signal therefrom. 
     Now, the operation of the heating, sterilizing and drying appliance according to the present invention will be described hereinafter. 
     First, in case of the heating appliance, the saturated steam produced by the boiler  11  of the saturated steam distributor  10  is set to a prescribed pressure by the pressure-reducing valve  16  and the safety valve  17 , and then passes through the valve assembly  13  so as to be supplied to the superheated steam generator  20 . 
     Then, pure saturated steam which has passed through the separator  12  is injected into the superheated steam generator  20  through the valve assembly  13 . In the meantime, the pure saturated steam is separated into water and vapor by the separator  12 , and the condensed water and the residual saturated steam which has not passed through the valve assembly  13  are discharged through the drain tube  14  for removal. 
     At this time, since the supply amount of the saturated steam which has passed through the valve assembly  13  is controlled by the concurrent or separate operation of the first and second electronic valves  13   a  and  13   b , it is adjusted depending on the state of the heating appliance. 
     In the meantime, the saturated steam supplied to the superheated steam generator  20  collides against the disc-like interval-maintaining members  23  or its molecules collide with one another to generate vortices while instantaneously passing through the fluid-communicating passageways  26  formed in the disc-like interval-maintaining members  23 - 1  and  23 - 2  of odd and even number rows. 
     At this time, the superheated steams passing through the fluid-communicating passageways  26  is heated by the superheated steam heating elements  22  to generate vortices, so that they are decomposed to small-sized molecules (clusters) while colliding with one another or the disc-like interval-maintaining members. 
     For this reason, the saturated steam becomes a superheated steam with permeability to thereby efficiently raise the temperature of the superheated steam. 
     That is, when the steam heated by the superheated steam heating elements  22  is vaporized, it needs an energy of 539 cal/g to thereby hold latent heat of vaporation. Thus, as the particles of the steam are smaller, they are more easily permeated to a to-be-heated object. 
     At this time, in case where a far-infrared ray ceramic heater  33  is further mounted at the heating place H, a typical shortcoming of the superheated steam, i.e., a phenomenon can be prevented where the superheated steam is condensed due to a cooling effect occurring immediately after being injected toward the heating place H. 
     Furthermore, since a far-infrared ray emitted from the ceramic heater  33  on which ceramic material is coated and latent heat which the atomized superheated steam has are utilized together, firing, heating or drying of a to-be-heated object is performed more rapidly to thereby improve a heating efficiency. 
     In addition, the superheated steam heating elements  22  of the superheated steam generator  20  is turned off so as to allow the saturated steam to pass through the first and second electronic valves  13   a  and  13   b  so that the saturated steam can be utilized as steam for cleaning purpose. 
     INDUSTRIAL APPLICABILITY 
     As described above, according to the heating, sterilizing and drying appliance using a superheated steam generator of the present invention, the saturated steams supplied to the superheated steam generator is heated while generating vortices by the unique construction of the superheated steam generator so that they are decomposed to small-sized molecules (clusters) to thereby improve the temperature efficiency of the superheated steam. 
     Further, the time and cost spent for generating the superheated steam is minimized, and the inner construction of the superheated steam generator is simplified to thereby reduce various expenses according to manufacture, maintenance and repair. 
     Moreover, with the combined use of a far-infrared ray ceramic heater, a typical shortcoming of the superheated steam, i.e., a rapid drop in temperature or condensation is prevented. Utilization of a temperature-increasing effect of the far-infrared ray and the latent heat of vaporation which the superheated steam holds can remarkably reduce the time required for heating for cooking, drying and sterilizing. 
     In addition, in case where the injection holes formed at the superheated steam injection line is clogged during the operation of the superheated steam generator, only the round screws used can be replaced with new ones without a need of exchanging the whole superheated steam injection line, thereby reducing various expenses according to the maintenance and repair of the system. 
     While the invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.