Method and apparatus for preheating pulverous materials prior to their introduction into a melting furnace

Combined apparatus for preheating glass furnace batch comprising an elongated vertically-mounted heat exchanger having a plurality of open-ended tubes extending throughout a major central portion of its height, means for delivering glass batch in fully intermixed condition to an upper region of said heat exchanger for its passage by gravity through said open-ended tubes, means for introducing hot gases from said glass furnace into a lower region of said heat exchanger to circulate upwardly between the said open-ended tubes, baffle means mounted around said tubes to direct said hot gases in a circuitous path around said tubes and out of contact with said glass batch for indirect heat transfer, and means for introducing a gaseous fluid at super-atmospheric pressure into the upper region of said heat exchanger to force the contained moisture downwardly, venting means located adjacent the lower end of said open-ended tubes to separate the contained moisture from said glass batch, and means for delivering the said glass batch to said glass furnace in essentially moisture-free preheated condition.

In the manufacture of glass, combined apparatus for preheating glass batch constituents comprising a glass melting furnace, a hollow duct for conveying hot gases therefrom, an elongated preheater for the glass batch constituents mounted vertically adjacent said glass melting furnace at an elevation higher than said furnace, open-ended vertical tubes extending through the major central portion of said preheater for conveyance of pulverous glass batch constituents therethrough by gravity, said hollow duct being connected to a lower region of said preheater for introducing the hot gases thereinto for passage upwardly around said tubes, baffle means mounted transversely of said tubes for directing said hot gases therearound in a circuitous countercurrent path for indirect heat transfer from said hot gases to said glass batch constituents, means for introducing a gaseous fluid at super-atmospheric pressure into an upper region of said preheater above said tubes to force the contained moisture within said glass batch downwardly through said tubes, venting means located adjacent the lower end of said tubes to eliminate the said contained moisture from said glass batch, and means for delivering the essentially moisture-free preheated glass batch into said glass melting furnace.

A process of heating a particulate material such as glass batch, individual glass batch constituents, glass cullet, mixtures thereof, and the like, which contain a volatile condensible constituent, comprising the steps of introducing the particulate material into the upper region of an enclosed tubular heat exchanger, allowing the particulate material to flow downwardly by gravity through a plurality of open-ended tubes of said heat exchanger, passing hot gases upwardly through said heat exchanger around the exterior of said open-ended tubes to heat the particulate material contained therein by countercurrent indirect heat transfer, increasing the internal pressure within an upper region of said heat exchanger by a gaseous fluid to thereby force the contained volatile constituent downwardly, venting the volatile constituent from within the particulate material exteriorly of said heat exchanger at a lower region thereof, and delivering the said particulate material from the bottom of said heat exchanger in heated condition essentially free of said volatile condensible constituent.

A heat exchanger for heating a particulate material such as glass batch, individual glass batch constituents, glass cullet, mixtures thereof, and the like, which contain a volatile condensible constituent, comprising an elongated vertically-mounted hollow enclosed chamber having a plurality of open-ended hollow tubes extending throughout a major portion of its height, means for delivering the particulate material to an upper region of said heat exchanger for its passage by gravity through said open-ended hollow tubes, means for introducing hot gases into a lower region of said heat exchanger to circulate upwardly between the said open-ended tubes, baffle means mounted around said tubes and out of contact with said particulate material for indirect heat transfer, means for creating super-atmospheric pressure within an upper region of said heat exchanger to force the contained volatile constituent downwardly, means for venting the volatile constituent from within the particulate material exteriorly of said heat exchanger at a lower region thereof, and means for delivering said particulate material at a lower region of said heat exchanger in heated condition essentially free of said volatile condensible constituent.