Method and device for continuous supply of lumps of material to a shaft

A method and a device is provided for continuously supplying from above piece-shaped, i.e. lumps of, material to a shaft through which a high-temperature gas is conducted from below upwardly to a centrally disposed upper gas outlet. The piece-shaped material at the upper end is fed into the shaft at the top via evenly distributed and closed feed tubes or via an annular feed gap adjacent the periphery of the shaft.

DESCRIPTION 
The present invention relates to a method and a device for continuous 
supply of preferably carbonaceous piece-shaped, i.e. lumps or particles 
of, material to a shaft through which gas at a high temperature is 
conducted to a centrally disposed upper gas outlet. 
The method and the device according to the present invention are adapted to 
enable gas at high temperature to flow through a shaft, for example a 
shaft furnace, in which slick is reduced. By this means, an outlet gas 
temperature of an order or magnitude of up to 1100.degree. C. is obtained. 
This high outlet gas temperature would exert a considerable action on the 
furnace lining if directly exposed to gases at such high temperatures. By 
filling the shaft with lumps of carbonaceous material, the shaft lining is 
protected against the direct action of the high outlet gas temperatures 
while at the same time the direct radiation heat from the reaction zone, 
which for example may be brought about by means of a plasma generator, are 
prevented from reaching the limiting surfaces of the shaft. 
It is desirable to create conditions within a shaft that the gas flow 
therein will take place substantially centrally within the shaft to an 
upper gas outlet, so as to avoid to the greatest possible extent excessive 
heat strains on the shaft lining and the feed arrangements through which 
the lumps of carbonaceous piece-shaped material are fed into the shaft. 
It is also desirable to bring about substantially constant gas flow 
conditions within the shaft permitting a combined cooling and regeneration 
of the exhaust gases enabling them to be used, for example, as reaction 
gas within the shaft. 
The present invention provides a method of supplying from above lumps of 
material to a shaft through which a high-temperature gas is conducted from 
below upwardly to a centrally disposed upper gas outlet, in which the 
lumps of material are fed into the shaft via evenly distributed and closed 
feed tubes or via an annular feed gap adjacent to the periphery of the 
shaft. 
The present invention also provides a device for carrying out the above 
process, the device comprising a shaft and, opening into the shaft 
adjacent to the periphery thereof, closed feed tubes or an annular feed 
gap opening into closed feed tubes or an annular feed gap. 
By feeding the lumps of material into the upper end of the shaft via evenly 
distributed and closed feed pipes or via an annular feed gap, the limiting 
surface of the material in the upper part of the shaft will form a conical 
groove corresponding to the natural angle of repose, which means that the 
material layer will cover the inner limiting surface of the shaft with an 
upwardly diminishing thickness. The distribution so obtained at the upper 
part of the shaft promotes a central gas flow within the shaft and 
outwardly through a centrally disposed gas outlet while at the same time 
the heat stress on the feed pipes or the feed gap can be reduced to a 
great extent. 
In order to facilitate the filling of lumps of material into the shaft, a 
distribution chamber is suitably provided ahead of the feed pipes or the 
annular feed gap, causing the material from the distribution chamber to be 
evenly distributed in a suitable way betweeen the pipes or over the whole 
feed gap. In order to reduce the risk of a flow of a gas through the feed 
pipes or the feed gap, there will be suitably provided at least one sluice 
chamber ahead of or behind the distributing chamber. In this case valve 
devices are provided between the distributing chamber and the sluice 
chamber, on the one hand, and the feed pipes and feed gap, on the other 
hand.

In FIG. 1 shaft 1 is provided with an upper gas outlet 3, the shaft being 
filled with piece-shaped material 2. This piece-shaped material 2 is 
supplied by means of closed feed pipes 4 evenly distributed around the 
upper periphery of shaft 1. 
The suitably carbonaceous, piece-shaped material is supplied from above by 
means of a conveying device having the general reference designation 10 to 
a feed hopper 9 and a first chamber 6a. From there the material is fed via 
a valve device 11 to a sluice chamber 6b for further conveyance to the 
distributing chamber 5 via a valve device 7. From the distributing chamber 
5 the material is automatically conveyed further to each branch tube 4' 
leading to one of the closed feed pipes 4. A valve device 8 is provided 
between each branch tube 4' and each closed feed tube 4. 
The arrangement comprising the various valve devices 7, 8 and 11 eliminates 
any tendency towards gas flow through the feed tubes 4, the branch tubes 
4', the distributing chamber 5 and the sluice chamber 6b. The gas flow 
that may occur during the short-time opening of the valve devices in 
connection with the the downward feed of the piece-shaped material towards 
the shaft and the temperature increase caused thereby in the feeding parts 
will be negligible, the temperature increase of the parts exposed to the 
gas flow being extremely moderate. 
The piece-shaped material 2 can advantageously be permitted to collect in 
the closed feed tubes 4 and thereby contributes towards a screening of the 
valve devices 8 against the high temperatures prevailing within shaft 1. 
By providing the inner surfaces of the closed feed tubes 4 with a lining 
of refractory material 4a, heat conducted by contact-transmission within 
the piece-shaped material will be prevented from damaging the feed tubes 
4. Piece-shaped material 2 within the feed tubes 4 will also protect the 
valve devices 8 against direct heat radiation from the interior of shaft 
1. 
By means of arrows a and A, FIG. 2 shows how the central gas flow is 
performed within shaft 1 towards the gas outlet 3.