Method of manufacturing a feeder channel for molten glass
Feeder channel for molten glass including an infrastructure including a block self-cast and sintered in situ. Furthermore, a method for manufacturing a block of such an infrastructure and a supply channel for a glassmaking furnace are claimed.
1. A method for manufacturing a block of an infrastructure of a feeder for a glassmaking furnace, the infrastructure comprising a block self-cast in situ and sintered in situ, said method comprising:
a) preparation of a self-castable unshaped product, activated and degassed under partial vacuum,
b) preparation, at the place where said block is intended to be used, of a mold corresponding to the shape of said block,
c) bottom feed of the mold, with at least partial removal of bubbles located at the surface of said self-castable unshaped product, activated, degassed and introduced into said mold, corresponding to the surface of said block intended to come into contact with molten glass;
d) hardening of said self-castable unshaped product, activated, degassed and introduced into said mold in order to form a preform;
e) optionally, mold release of said preform;
f) heating-up in order to dry and sinter said preform.
2. The manufacturing method as claimed claim 1 , in which, in step c), bubbles are removed so that surface of the block intended to be in contact with molten glass has:
if the length (L) of the block is equal to or greater than 1 m,
on any square C measuring 10 cm×10 cm:
no more than one bubble having a diameter greater than 5 mm and
no more than 1 bubble having a diameter between 3 and 5 mm, and
no more than 22 bubbles having a diameter lower than 3 mm, and
per meter along the length of this surface:
no more than 2 bubbles having a diameter greater than 5 mm, and
no more than 40 bubbles having a diameter between 3 and 5 mm, and
no more than 200 bubbles having a diameter lower than 3 mm, or
if the length (L) is lower than 1 meter,
no more than 2 bubbles having a diameter greater than 5 mm, and
no more than 40 bubbles having a diameter between 3 and 5 mm, and
no more than 200 bubbles having a diameter lower than 3 mm.
3. A method for manufacturing a feeder for a glassmaking furnace comprising the following steps:
A. manufacture, using a manufacturing method as claimed in claim 2 , of an infrastructure block comprising a base and two jambs;
B. optionally, assembly of one or more burner blocks above at least one of said jambs;
C. installation of a mold having a shape adapted to the manufacture of a superstructure block;
D. casting of an unshaped product in said superstructure mold.
4. The method as claimed in claim 3 , in which an infrastructure block and a superstructure block are manufactured simultaneously by casting.
5. The method as claimed in claim 3 , in which a core used to define an internal surface of said infrastructure block is used to define an internal surface of a superstructure block placed above said infrastructure block.
6. The manufacturing method as claimed in claim 3 , in which each of the jambs extends from said base to a free end bounded by an upper surface having the appearance of a casting face.
7. The manufacturing method as claimed in claim 1 , in which said block has the shape of a U-section.
8. The manufacturing method as claimed in claim 1 , in which said block has a length, measured along the longitudinal direction (X) of the feeder, that is greater than 0.7 m.
9. The manufacturing method as claimed in claim 8 , in which said length is greater than 1 m.
10. The manufacturing method as claimed in claim 9 , in which said length is greater than 2 m.
11. The manufacturing method as claimed in claim 10 , comprising a casing in which said block is placed, said length being equal to the length of said casing.
12. The manufacturing method as claimed in claim 1 , in which said block comprises grains and a hydraulic binder.
13. The manufacturing method as claimed in claim 12 , in which the alumina cement content is higher than 2% and lower than 8%, in percentage by weight in relation to the oxides.
14. The manufacturing method as claimed in claim 1 , in which said block has a composition such that the total Al 2 O 3 +ZrO 2 +SiO 2 +CaO+MgO+TiO 2 +Y 2 O 3 content is higher than 90%, in percentage by weight in relation to the oxides.
15. The manufacturing method as claimed in claim 14 , in which said block has a composition such that the total Al 2 O 3 +SiO 2 +CaO+Y 2 O 3 content is higher than 90%, in percentage by weight in relation to the oxides.
16. The manufacturing method as claimed in claim 15 , in which said composition is such that, in relation to the weight of the oxides and for a total of 100%:
Al 2 O 3 >80%,
SiO 2 <10%,
CaO<5%,
Y 2 O 3 <5%,
other oxides <5%.
17. The manufacturing method as claimed in claim 1 , in which said block has a composition such that the total Al 2 O 3 +ZrO 2 +SiO 2 +CaO+Y 2 O 3 content is higher than 90%, in percentage by weight in relation to the oxides.
18. The manufacturing method as claimed in claim 17 , in which said composition is such that, in relation to the weight of the oxides and for a total of 100%;
Al 2 O 3 >45%,
25%>SiO 2 >5%,
35%>ZrO 2 >8%,
CaO<5%,
Y 2 O 3 <5%,
other oxides <5%.