| Abstract: | In one of the glass sheet tempering processes in which a glass sheet is submerged in molten metal with electromagnetic force by a linear induction motor (LIM), it is necessary to keep the glass sheet vertical in the center of the molten metal tank, because a glass sheet warps unless both sides are uniformly cooled. This paper describes the concept of the center of the buoyancy force on a glass sheet in molten metal, introduced in order to discuss its stability against tilt. If the center of the buoyancy force of a glass sheet is higher than its center of gravity, it is stable against tilt. Numerical simulation of electromagnetic fluid flow is performed to evaluate the center of the buoyancy force. The stability conditions are the following (where τ is the pole pitch of the LIM): (1) The shortest length of a glass sheet is 2τ/3 shorter than that of the LIM. (2) The lowest limit of the center of gravity of a glass sheet is τ/3 higher than the center of the LIM. © 1999 Scripta Technica, Electr Eng Jpn, 126 (3): 64–72, 1999 |
