Float Glass Kiln Structure (4)

Part three Neck and cooling end

Neck is located between melting end and cooling end for installing cooling water bag and blender, neck can block air stream from melting end which will affect glass be formed in cooling end.

Well melted glass liquid’s viscosity is small and not suitable for glass forming, we need to higher the viscosity to meet standard required by cooling glass liquid, so appear cooling end. Cooling end structure is basically same as melting end, it also has upper space and lower tank kiln. The difference is breast wall height is lower than melting end, tank wall depth more shallow than melting end’s tank wall. Cooling way usually are natural cooling, mainly rely on glass liquid surface, tank wall and tank bottom’s natural cooling evenly and slowly.

1. Neck and cooling end structure

(1) Neck structure

Since float glass tech appears, neck structure usually uses dwarf crown structure and hang wall structure

① Dwarf wall structure. Float glass process line’s dwarf wall first be used in China; the crown span and height of back gable crown, neck crown in melting end is same or similar as cooling end’s front gable crown, breast wall is not so high, some neck crown ballast brick directly on the tank wall to reduce space develop (this is neck structure without blender). With the develop of hi-tech and people’s higher quality required for glass, blender appears in neck structure. Blender has two type: vertical and horizotal. Vertical blender insert from neck crown roof’s hole, this type blender has no required for breast wall’s height, while horizotal blender need higher breast wall, since it was insert from both breast wall side (crown roof no need have hole) and need the neck breast wall has hole 300 mm height and length enough.

② hang wall structure

Dwarf crown structure’s span ratio is small based on crown’s safety factor, so its space open is large and separation function not so good. Especially the horizotal blender, as the breast wall get higher, the blender cannot perform so good. So the hang wall structure appears. This structure can larger the span ratio, enhance security, and the space separated rely on hang wall. Hang wall block usually used high quality silica brick or sintered mullite block.

Besides, there also has other neck structure like U shape hang crown, double L shape hang crown, hang jack crown, etc. Those neck structure is complex and need larger investment, usually can be found in high grade glass process line.

(2) Cooling structure

Cooling end function is cooling well melted glass liquid evenly.

Cooling end also contains crown, crown springer, breast wall, tank wall, tank bottom and other related steel structure. Structure almost like melting end, while the refractory material not same as melting end. High grade glass process line, its tank wall and bottom in cooling end usually using α-βAl2O3 block, under the pave brick is α-βAl2O3 ramming mass, this material is zero pollution, null foaming index; and breast wall and crown use high quality silica block. 

To be continue...