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Summary
“Development Of
Ecologically Clean System Of Coke Oven Construction”
Author Artem Golubev
INTRODUCTION
The coke production
is an important section of metallurgical
production cycle, as it is a supplier of
restorer ferric - a technological fuel for blast furnaces. In
connection with expected growth of ferrous metals consumption in the nearest decades the most
important problem of coke-chemists is expansion of raw materials coking base and decision
of sharp ecological production problems
.
One of the
expansion directions of coal variety for coking and reduction of its cost is a
density increase of the coal loading in
coke camera by ramming way.
The main advantage
of coke ovens with coal mixture ramming
is a possibility to receive the qualitative blast
furnace coke from coal mixture, which contains up to 70% gas and longflame coals, deposits of which in
Besides that coke
ovens with coal mixture ramming have a number of serious disadvantages, they
are the following:
- emission of gas
and dust in great amount on a servicing platform and a load machine while
pushing coal cake when worsens the labour
conditions of servicing personnel;
- when the
toughness of a coal cake is not
sufficient its destruction occurs during loading, which leads to greater
expenditures of time and labour on coal
removing from a camera;
-loading of the
coke cake into the coking coach and its transportation to a quenching plant is
accompanied by carbon-monoxide fumes of coke
and emission of a big amount of harmful gases and dust into the
atmosphere.
The closest to a
designed prototype of a coke oven is continuously acting horizontal coke oven,
including coking camera, camera with crater (the bunker) for coal mixture
loading and device for pushing coal into
a coking camera , as well as camera for coke cooling and bunker for coolled
coke.
Advantages of such an installation for coal mixture coking are the following:
-a possibility to
liquidate completely emissions of harmful gases and dust into the atmosphere
when loading the coal mixture and unloading of coke;
-prevention the
contact of overheated coke with atmospheric air and its carbon-monoxide fumes;
- a reduction in
the number of servicing machines and personnel, improvement of labour conditions.
The main
disadvantage of such an installation is a big pushing effort of coal from camera into coking camera
because of the plastic mass formed on surfaces of the coal cake and increase of
adhesive power with wall.
The other
disadvantage of the described installation is a loss of physical heat of coke, since design of the
cast-iron panels, forming the walls of the camera-cooler, does not allow to get
the vapour of necessary parameters for use in technological process or in a
steam turbine.
The purpose of the
given work is a loading device simplification , reduction of pushing
effort of coal cake and probability of its destruction, preventing
exception the surge of gas and dust into the atmosphere while loading coal and
unloading, utilization of the coke heat
for steam production.
MAIN PART
A plant for coal
mixture ramming works in the following way. Coal mixture supplied by a conveyor
system into a bunker-accumulator on a load
machine, whose capacity is calculated to load 3-4 coke cameras.
From the bunker
coal is distributed by feeders evenly along the length of a camera and is
packed down by mechanical rammers. When the given height of a coal cake is
reached the coal supply into a camera and ramming are stopped, then frontal and
lateral walls of camera are opened and coal cake is pushed into a tray in a
coking camera through opened door from
machine side. After the cake has been fixed tray is extracted from the camera
and the door is fixed on it, and on ramming-load machine the cycle of
operations of a new coal cake formation is repeated .
The container
for coal ramming has a cross-section,
corresponding to section of the coking camera
and a neck, slightly expanding into the side of cake pushing (on 10-20
mms), but its useful length is 1/2 - 1/3 lengths of the coking camera. Such
correlation defines the time lag between
next pushing, equal 1/2 -1/3 of coking period, which is sufficient to
form on surfaces of a earlier loaded pie a layer of coke-selfcoke thickness 100-150 mms, effort of the pushing
falls due to that.
Cameras for coke cooling are designed in the manner of twodrummed
steam boilers, boiling pipes of
which form the lateral walls of the
cameras-refrigerator and lined from the side of coke cake by cast-iron plates.
CONCLUSIONS
Offered system of
coke ovens has the following advantages:
- simplicity and
reliability of a device for loading rammed coal mixture;
- reduction of pushing
efforts of coal-coke cake into a coking camera due to the fact that during the
period between pushings, which is 1/2-1/3 coking periods, thick layer of coke-selfcoke is formed (~120 mms), on surfaces of the coal cake the
power of friction of layer with wall of the camera is far less, than of a
plastic layer;
- absence of gas and dust releases into the
atmosphere, due to full encapsulating the coking camera in coking process, loading the coal cake and
pushing of coke;
- utilization of
the coke heat for steam production;
- reduction of
number of machines, equipment and personnel servicing coke ovens, as there is
no need to use machine from coke side, coach, quenching tower and coke
footlights.