| 摘要 |
1527155 Alkali metal silicate glass PHILADELPHIA QUARTZ CO 25 May 1976 [29 May 1975] 21564/76 Heading C1M A soluble alkali metal silicate glass having a mol. ratio of Si0 2 : M 2 0 of 1À5-4À5:1 (where M is Na and/or K), a water content of 0À05-2% by weight, and including sufficient bubbles so that the solid product glass may be easily fractured, is made by: (a) charging an alkali metal oxide source (e.g. sodium carbonate and/or potassium carbonate) and a silica source (e.g. sand) to an open-hearth furnace; (b) maintaining the furnace temperature (e.g. at above 1093‹ C.) so as to form a melt of the glass on which unmelted raw material floats; (c) passing dry saturated steam under pressure through the melt from bubbling means located in the furnace bed, there being an average of 1 bubbling means for each 8-30 ft<SP>2</SP> of bed, the pressure being such that 5-20 bubbles per second (each of diameter 8-18") are produced from each said bubbling means (e.g. 2À5-150 p.s.i.g.); and (d) withdrawing the melt from the furnace. |
