US 11,805,937 B2
Heating cooker using ceramic heating element and manufacturing method therefor
Jong Hyun Kim, Busan (KR)
Assigned to PELLYTECH CO., LTD., Busan (KR)
Appl. No. 16/096,539
Filed by PELLYTECH CO., LTD., Busan (KR)
PCT Filed Apr. 25, 2017, PCT No. PCT/KR2017/004364
§ 371(c)(1), (2) Date Oct. 25, 2018,
PCT Pub. No. WO2017/188695, PCT Pub. Date Nov. 2, 2017.
Claims priority of application No. 10-2016-0049799 (KR), filed on Apr. 25, 2016.
Prior Publication US 2019/0133370 A1, May 9, 2019
Int. Cl. C04B 41/45 (2006.01); A47J 36/04 (2006.01); C04B 35/622 (2006.01); A47J 36/02 (2006.01); C04B 35/626 (2006.01); C04B 35/63 (2006.01); C04B 33/138 (2006.01); C04B 33/132 (2006.01); C04B 35/82 (2006.01); C04B 33/135 (2006.01); C04B 35/26 (2006.01); B05D 3/02 (2006.01); B05D 5/08 (2006.01); B05D 3/12 (2006.01)
CPC A47J 36/04 (2013.01) [A47J 36/027 (2013.01); B05D 3/02 (2013.01); B05D 3/12 (2013.01); B05D 5/08 (2013.01); C04B 33/138 (2013.01); C04B 33/1324 (2013.01); C04B 33/1352 (2013.01); C04B 35/26 (2013.01); C04B 35/6263 (2013.01); C04B 35/62204 (2013.01); C04B 35/6316 (2013.01); C04B 35/82 (2013.01); C04B 41/45 (2013.01); C04B 41/4507 (2013.01); C04B 41/4539 (2013.01); C04B 41/4576 (2013.01); C04B 2235/3272 (2013.01); C04B 2235/3418 (2013.01); C04B 2235/5256 (2013.01); C04B 2235/5427 (2013.01); C04B 2235/5454 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A method for manufacturing a ceramic cooker comprising a ceramic heating element, the method comprising:
a cooker body preparation step of preparing a cooker body by molding;
a heating element material preparation step of preparing, as a microwave-absorbing ceramic element material, any one or more selected from among mill scale, steelmaking slag and magnetite (Fe3O4), which are ferromagnetic materials and have a particle size of 3 mm or less;
an inorganic binder preparation step of preparing, as an inorganic binder, a colloidal silica sol having a colloidal silica content of 8 to 30 wt % by adding acetic acid to sodium silicate in an amount of 1.2 to 2 parts by weight of acetic acid based on 100 parts by weight of sodium silicate, followed by stirring for 30 minutes to 1 hour, thereby forming a silicate, and then adding a solvent to the silicate such that a content of the solvent is 70 to 92 wt %, followed by stirring for 2 to 3 hours;
a mixing step of mixing 20 to 40 parts by weight of the colloidal silica sol as the inorganic binder with 100 parts by weight of the heating element material, thereby making a heating element paste;
an application step of applying the heating element paste, obtained by the mixing, to a bottom of the cooker body; and
a drying and curing step of drying and curing the heating element paste applied to the bottom of the cooker body at a thickness of 1.5 to 2.0 mm, thereby forming a solid heating element,
wherein the solid heating element is porous and in which pores are formed between particles of the solid heating element, and
wherein at a high-frequency output of 700 W, heating performance corresponding to a temperature of 300 to 320° C. appears such that the heating element paste remains completely attached to the bottom of the cooker body, and at a high-frequency output of 1000 W, heating performance corresponding to a temperature of 350 to 400° C. appears such that the heating element paste remains completely attached to the bottom of the cooker body.