| 摘要 |
A method and apparatus for preparing glass beads utilizes an equation solving for the relaxation time of molten glass filaments, which is the elapsed time from when a molten stream breaks up as a result of force imparted on the stream until reaching the relaxation point, at which a maximum percentage of filaments have formed round beads. The equation for relaxation time is tau =(d• mu )/ sigma , wherein tau is the relaxation time; d is the diameter of the formed round beads; mu is the viscosity of the filaments during the relaxation time; and sigma is the surface tension of the filaments during the relaxation time. The system for preparing glass beads is configured based on this equation by selecting certain parameters such that the relaxation point is achieved just when the round beads are exiting a heated region of the system and entering a cooling region, for example, the atmosphere. These parameters include the degree of heat applied both to melt the glass raw materials and to sustain the heated region, the length of the heated region, the force applied to the stream, and the composition of the molten glass. Typically, when designing a new system, all other parameters except for the length of the heated region are fixed, and the length is determined from the above equation. On the other hand, after a system is in place, the length of the heated region is usually fixed, and the force applied to the stream is determined based on the other parameters. In this way, a relatively high fraction of round beads are formed, even when relatively small beads are desired. |
