Patent Publication Number: US-2011068094-A1

Title: High energy efficient electric cooking system

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention is related to the electric range top cooking system which includes the electric burner, the cooking pot, the ceramic base plate and the thermal insulation unit. 
     2. Description of the Prior Art 
     Almost every family in the world has to cook food. In the modern society, the energy used for cooking is far more than used in transportation. However, the energy efficiency of the cooking is much lower than the transportation; most of the heat generated for cooking is wasted. Ironically, nowadays, due to increase of oil price, global warming effect and gradual depletion of natural resources, governments and scientists around the world are making great effort in design of more fuel efficient vehicles and airplanes, but pay much less attention on improvement of the energy efficiency of cooking. Actually, a little improvement of energy efficiency in the cooking will have far more impact on energy consumption than that by the improvement of transportation. To cook food, the food must be heated and the temperature of the food must reach certain level and should be maintained for certain period of time. At present, the typical electric range top cooking system is shown in the  FIG. 1 ,  FIG. 2  and  FIG. 3 .  FIG. 1  is the typical flat coil type electric burner  1 , which has the spiral tubular heating element  2  and the two terminal mounting legs  3  which are connected to the electric terminal;  FIG. 2  is the dip pan  4  which is placed under the electric burner  1  to support the electric burner  1 , the dip pan  4  is normally made of steel which is highly heat conductive;  FIG. 3  is the assembly of the cooking system  10  on the top of a typical residential electric range which includes the cooking pot  11  (includes the lid and the pot body), cooking content  14  (food), the electric burner  1  and the dip pan  4 ; the  13  is the top surface of the electric range where the dip pan  4 , the electric burner  1  and the cooking pot  11  are located. 
     Let&#39;s focus on  FIG. 3 . The burner  1  generates heat when the electricity passes through it; the arrows of  FIG. 3  indicate the directions of heat diffusion. Due to the fact that the cooking pot  10  sits on the top of the burner  1 , the bottom and the sides of the burner  1  is open to the air, so there is less than half of the heat (indicated by the up vertical direction arrows) enters the pot  10  and is absorbed by the food  14 , it is this portion of the heat to cook the food; more than half of the heat moves downward and sides, which is totally wasted, such wasted heat causes the range surface near the burner to be very hot. 
     In addition to the severe heat lose from the burner bottom and sides, there is substantial heat lose (indicated by the side arrows and top arrows) from cooking pot  10  to the environment. In  FIG. 3 , the burner temperature can be high up to 600° C. to 700° C., with such temperature, it is not practical to place a thermal insulation material around the side of the cooking pot to reduce the heat lose from side of the pot; furthermore, any air movement around the cooking system  10  will accelerate the heat lose (wind effect); therefore, the temperature increase of the cooking content is substantially slow due to such heavy heat lose. In general, the energy efficiency of the cooking in such assembly is about 35% or less. 
     Another popular type of electric range is the smooth ceramic glass cooktop range, the electric burner is under the top ceramic glass, the energy efficiency of this type is very low also. 
     The world population of the people is fast increasing, the consumption of the natural energy resources has been steadily increasing, which has dramatically impact to the environment and is the major contribution to the global warming effect. The limited energy resources are depleting. So it is strongly desirable to invent a cooking system with better energy efficiency with affordable cost. This not only reduces the family&#39;s electric bill, but also reduces the carbon dioxide emission, therefore, reduce the global warming effect. 
     It is an object of the present invention to introduce an electric cooking system with much higher energy efficiency and much less consumption of electricity and reduce living cost of normal families. 
     It is another object of the present invention to introduce an electric cooking system with much higher energy efficiency which can be installed on the common residential electric ranges, therefore substantially reduces the cost of such improvement. 
     SUMMARY OF THE INVENTION 
     The present invention includes a new designed electric burner with vertical heating structure, a cooking pot with an open inward slot at the bottom in which the vertical heating structure of the burner is inserted, a ceramic or ceramic-glass plate on which the electric burner is sited, a thermal insulation unit placed around the side of the cooking pot to reducing the heat lose from the side of the pot during the cooking. In this invention, almost all heat generated by the burner is absorbed by the food and the heat lose is substantially lower than the current conventional electric cooking system. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 4  is the perspective view of the new designed electric burner with vertical heating structure and two terminal mounting legs. 
         FIG. 5  is the top view of the electric burner. 
         FIG. 6  is the perspective view of the mounting leg secure element. 
         FIG. 7  is the perspective view of the electric burner support element. 
         FIG. 8  is the perspective view of the assembly of the electric burner. 
         FIG. 9  is the ceramic or ceramic-glass plate on which the electric burner is placed. 
         FIG. 10  is the cross section view of the ceramic plate. 
         FIG. 11  is the perspective view of the assembly of the electric burner and the ceramic plate. 
         FIG. 12  is the cross section view of the metal cooking pot with an inward rectangle open slot at the bottom. 
         FIG. 13  is the cross section view of the cooking pot which is 90 degree respective to the  FIG. 11 . 
         FIG. 14  is the perspective view of the cooking pot with inward open slot (shown in dash lines) at the bottom. 
         FIG. 15  is the perspective view of the thermal insulation sleeve which will be placed around the cooking pot to reduce the heat lose from the cooking pot. 
         FIG. 16  is the cross section view of assembly of the electric burner inserted into the open slot of the cooking pot. 
         FIG. 17  is the cross section view of the assembly of the cooking system by the present invention. 
         FIG. 18  is the perspective view of the electric burner designed for the smooth ceramic glass cooktop range. 
         FIG. 19  is the cross section view of the ceramic glass cooktop where the burner is mounted. 
         FIG. 20  is the cross section view the electric burner of  FIG. 19  mounted on the smooth ceramic top range. 
         FIG. 21  is the perspective view of the coil cooktop range installed with two present electric burners of  FIG. 4 . 
         FIG. 22  is the perspective view of the smooth ceramic glass cooktop range installed with two present electric burners of  FIG. 18 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Refer to  FIG. 4  to  FIG. 17 . In the  FIG. 4 , the electric burner  20  is made of tubular heating element, has two terminal mounting legs  21  and  22  which are the similar to the two terminal mounting legs  3  of conventional electric burner  1 ; at the position  23  of leg  21 , the tubular element is bent 90 degree horizontally toward the middle; at the middle position  24 , the tubular heating element is bent up vertically; at the position  25 , the tubular heating element is bent horizontally along the central line; at the position  26 , the tubular heating element is bent down vertically, then bent to horizontally back to the position  27 , continue such construction (depending on the size of the heating element and the desired power of the burner) until the vertical heating structure  35  is finished at the position  28 ; at position  28 , the tubular heating element is bent down vertically, at the position  29 , the tubular heating element is bent horizontally outward and perpendicular to the vertical heating structure  35 ; at the position  30 , the tubular heating element is bent horizontally 90 degree to make the terminal mounting leg  22 . The position and distance of the two legs  21  and  22  are secured by the metal piece  31  shown in  FIG. 6  and  FIG. 8 , which is similar to the conventional tubular burner  1 .  32  is the terminal pin which is extended to the position  28 , the terminal pin of the leg  21  is also extended to position  33  while is at the same level of position  28 , the heating resistor is inside of the metal sheath of the tubular heating element and starts at position  28  and is extended through the vertical structure  35  and ends at the position  33  of the vertical structure, so only the vertical structure  35  of the burner  20  generates the heat.  FIG. 5  is the top view of the said electric burner  20 .  FIG. 6  is the mounting leg secure element with two holes which are to secure the distance of the two legs and their positions.  FIG. 7  shows the metal support  40  for the electric burner  20 , there are two metal tips  41  on the top of the support to be cramped onto the burner  20  shown on  FIG. 8 .  FIG. 8  shows the assembly of the electric burner  20 , the mounting leg secure element  31  and the metal support  40 . 
       FIG. 9  shows the base plate  50  which is made of ceramic or ceramic glass; the  FIG. 10  is the cross section view of the base plate  50 . The base plate is round, there is an open slot  51  along the central line, the width of the open slot  51  should match the diameter of the tubular heating element of the burner  20 ; the second slot  52  is located at other side of the plate and perpendicular to the open slot  51 , the size of the slot  22  should match length and the width of the metal support element  40 , i.e., the metal support element  40  is inserted into the slot  52 . The base plate  50  has a top portion  53  with a larger diameter than the lower portion  54 , the diameter of the lower portion  54  of the base plate  50  should match the opening on the top of the electric range where the dip pan is normally installed, so it can be easily installed into the opening.  FIG. 11  shows the configuration after the said electric burner  20  is installed onto the base plate  50 . 
       FIG. 12  is the cross section view of the cooking pot  60  (the lid is not shown), the cooking pot  60  has an inward open slot  61  at the bottom, the open slot  61  has a rectangular shape, the size of the open slot  61  should match the size of the vertical heating structure  35  of the electric burner  20 .  FIG. 13  is the cross section view of the cooking pot which is 90 degree respective to the  FIG. 12 .  FIG. 14  shows the location of the open slot  61  (in dash line) inside the cooking pot  60 . 
       FIG. 15  is the cylinder-type thermal insulation sleeve  70  which can be made of non flammable and thermal insulation fibers or other materials. This insulation sleeve is placed around the side of cooking pot  60  to prevent the heat lose from the cooking pot  60 . The size of the insulation sleeve  70  should match the size of the cooking pot  60 . 
       FIG. 16  is the cross section view that the vertical heating structure  35  of the electric burner  20  is inserted into the open slot  61  of the cooking pot  60 . 
       FIG. 17  is the cross section view of the assembly of the present cooking system  80 . One can see that the vertical heating structure  35  is inserted into the middle open slot  61 , therefore, almost 100% of the heat generated by the vertical heating structure  35  enters the cooking pot  60  and absorbed by the cooking content  14 , this is significantly improvement of the energy efficiency compared to the conventional coil type burners; furthermore, the ceramic or ceramic-glass base plate  50  is a very good thermal insulator which efficiently prevents heat lose from the bottom of the cooking pot  60 . If the thermal insulation sleeve  70  is used, the heat lose is even further reduced. Therefore, overall, this cooking system improves the energy efficiency up to 3 to 4 time. There is still some heat lose from the top lid of the cooking pot  60 , such lose is the same as the conventional cooking system  10  shown in  FIG. 3 . Another advantage of the present cooking system  80  is that if the thermal insulation sleeve is used, the heat lose due to air movement around the cooking system  80  (wind effect) is much less than the conventional cooking system  10 . Overall, the heat accumulation inside the cooking pot  60  is much faster than the conventional cooking system  10 ; the temperature of the cooking content  14  in  FIG. 16  rises much faster than that in  FIG. 3 . Theoretically, the energy efficiency of the present cooking system  80  can be up to more than three times of the conventional cooking system  10  based the assumption that the same amount of heat is generated by the present electric burner  20  and the conventional electric burner  1 ; in other word, a 500 watts present electric burner  20  is equivalent to a 1500 watts conventional electric burner  1 . Therefore, people can save about ⅔ of the electricity used for cooking, such saving will substantially reduce the electric bill; this, in turn, reduces the electricity production of power plants which use coal, natural gas, oil and nuclear material to produce the electricity, therefore, reduce the consumption of the natural resources and global warming effect. 
     The cost of the present cooking system  80  should be comparable to the conventional cooking system  10 , because much less tubular heating material is needed to make electric burner  20  than the conventional electric burner  1 , it is also unnecessary to use the dip pan  4 , so those savings should be able to roughly compensate the cost of insulation sleeve  70  and the ceramic base plate  50 . 
     Due to the special configuration of the present burner  20 , the present cooking system  80  is more suitable for cooking food with sufficient quantity and pretty of liquid (such as water or oil), actually, more than half of families&#39; daily cooking match those conditions. 
     The common electric range has two smaller burners and two larger burners; it will be the best combination to replace two conventional burners with the present burners (one smaller and one larger), so people will have choice to select which burner to use based on what to cook. 
     The present burner  20  can be applied also to the smooth ceramic glass cooktop ranges without any technical difficulty. 
       FIG. 18  is the electric burner  90  designed for the smooth ceramic glass cooktop range. In this design, the two mounting legs  91  and  92  are vertical. 
       FIG. 19  is the cross section view of the smooth ceramic glass cooktop  95 , there are two holes  96  and  97  in the ceramic glass, the electric burner  90  can installed to the ceramic glass cooktop. 
       FIG. 20  is the assembly of electric burner  90  installed to the ceramic glass cooktop  95 , and connected to power cables  100 . 
       FIG. 21  is the perspective view of the electric burner  20  installed on the flat coil top electric range. 
       FIG. 22  is the perspective view of the electric burner  90  installed on the smooth ceramic glass cooktop range. 
     It should be understood that modifications of this invention will occur to those skilled in this art, therefore this invention is not limited to the particular embodiments disclosed but that it is intended to cover all modifications which are within the true spirit and the scope of this invention as claimed.