Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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~ACKGRO~JD O~ ~E~ INVE~ION
I. ~ield o~ the applîcation
~ he in~ention relates to the practice o~ cooling the
rotary kiln shell, and more particularly, to an apparatus
~or the xemoval o~ hea~ ~rom the cylinders of the rotary
recuperator cooler.
2 Description o~ the prior art
~ here is known in the art an appara~us ~or cooling the
shell o~ a rotary kiln, ~hich comprises a spiral of tubi~g
arr~nged around the kiln shell with a space being ~ormed there-
between; a coolant such as water circulates through said
tubing. ~he tubes are ~ixed on support members. Mounted above
the tubes are ba~les.
Since carrier rings are not pxovided for in the appara-
tus construction, it is impossible to ens~re strictly con-
centrical arrange~ent o~ the tubes. ~he misalignment o~ the
~ubes results in the impainnent o~ the heat exchange bet-
ween the kiln shell and the tubesO
In additionl such tube arrangement makes it impossible
to conduct the i~spection o~ the kiln shell during operation.
~urthe~more, the tube-mounting operation requires welding
of an appreciable amount o~ separate hal~-turns o~ the tubesO
~he ~pparatus dismounti~g is like~vise labour-consuming
operation. Due to the absence o~ either housing or in~ula
tio~ above the ba:E~fle~, the latter undergo abrupt cooling
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7~63
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in the winter time and fail to re~lect heat~
There is also known an apparatus for remov~ng heat
from the shell of the rotarv k~ln recuperator cooler, which
comprises heat-exchange tubes i~ntended for a coolant to circulate
therethrou~h and fixed sectionwise on support members which
concentrically encompass the kiln shell, the heat-exchanae
tubes being secured on the support members so as to encompass
the kiln shell around i-ts periphery with an annular space being
formed between the tubes and the housing surface To enhance
the heat-removing efficiency, heat shie:Lds are arranged above
each tube section or directly on the tubes.
The main disadvantage of the above-described apparatus
i~ applied to the recuperator coolex, lies in its low cooling
e~ic~iency which is due to insufficiently developed heat-
transfer area of the tubes. In addition, the apparatus of
this type is complicated for maintenance and repairr the tube
heat shields making the cooler inspection difficult.
It is an object of the invention to provide an apparatus
for removin~ heat from cylinders of the rotary kiln recuperator
cooler, which will permit the heat-transfer area thereof to be
increased.
Another object of the invention is to provide an
apparatus of the type permittin~ the mountina and servicing
of the heat--exchange tubes to be substantially simplified.
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Accordingly, the present invention provides an
apparatus for removing heat from a rotary kiln recuperator
cooler having an axis and a pluralit~ of cylinders which have
outer surfaces and are arranged circumferentially about the
axis, the apparatus comprising: at least two substantially
bow-shaped stationary support members spaced from one another
in an axial direction and each having a lateral surface which
faces toward a Lateral surface of the other support member; a
plurality of heat-exchange tube means through which a coolant
is adapted to circulate, said tube means being fixed to said
lateral surfaces of said support members such that said tube
means are spaced from each other in a substantially circumferen-
tial direction and arranged radially outwardly of the cyllnders
in the vicinity of the latter along a wave line, so that a space
of variable dimension is defihed between said heat-exchange
tube means and the outer surfaces of the cylinders thereby
permitting the heat-transfer area to be increased, wherein each
of said heat exchange tubes has an axis; and further comprising
a plurality of heat-removing elements which are constituted of
~0 a high temperature resistant material and mounted on each of
said heat-exchange tubes for rotation about the axis of the
same tube so as to be periodically brought into contact with
the outer surfa~e of the cylinders. Owing to such arrangement
of the heat-exchange tubes, as well as due to the space formed
between the surfaces of the cylinders and the heat-exchange
tubes being of variable cross section, the heat-transfer area
is substantially increased and, consequently, a greater amount
of heat is removed from the cooler.
This is explained by the fact that the heat-transfer
intensity is influenced by the suxface area of the heat-exchange
tubes rather than by the distance thereof from the surfaces of
the cooler cylinders.
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~ loreover, with the space between the heat-exchange
tubes and the surface of the cooler cylinders being of variable
cross section, the apparatus servicing becomes easier.
It is preferable to mount on the heat-exchange tubes
heat-removing elements rotatable about their axes, made of
a high-temperature-resistant material and periodically brought
in~o contact with the surfaces of the cooler cylinders.
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~7~63
This will in~e~si~y the rate o~ heat removal from the
cooler ef~ected by the heat-exchange tubes.
BRI~ DESCRIP~ION OF ~HE DRAWI~GS
~ he invention will be further described~ by way o~
e~ample only, with re~erence to the accompc~nyings drawings9
in which:
~ ig.l is a side view o~ a part of a ro~ary kiln, as
see~ from the dischar~e end thereo~, provided with a recu-
perator coole,r around which there is arranged an apparatus ,
for removing heat ~rom the cooler cylinders~ according to
tha invention;
~ ig.2 is a cross-section taken along line II-II of
Fig~l;
~ ig.3 is a view o~ a uni~ A of Fig.2 (heat-removing
plates mounted on the heat-exchange tubes).
DE~AII~D ~ESCRIPTIO~ O~ TH~ PRE~E~RED E~BODIM~
Re~erring now to the above drawings, and to ~`igol in
particular, there is shown therein a rotary kiln 1 at the
disGharge end of which there is mounted a recuperator cooler
2 whose c~linders 3 ~re concentricall~ arranged around the
kiln discharge end and connected to the kiln I through branch
pipes 4.
~ he hot burned material ~rom the kiln I is passed
through the branch pipes 4 to the cyli~ders 3 where its cooled
~ 5
i~,
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by a flow o~ air supplied therein. The cooled ma~erial is
then trans~erredTonto a conveyer (no~ shov~). In ~he course
o~ opera~ion the red-hot c~linders give o~ a great amount
of heat lo~t to the atmosphere. ~o collect the ~vasted heat 9
an apparatus 5 ~or removing heat from the cylinders 3 o~ the
cooler 2 is arranged arou~d the cylinders 3.
~ he appar~tus 5 according to the invention comprises
heat-exchange tubes 6 intended ~or a coolan~ to circulate
therethrough. These tube are secured in sec~ions on the late-
ral surtace o~ bow-shaped support members 7 arranged length-
wise o~ the cooler 2.
l~ach o~ the ~upport members 7 is made split and consists
o~ two parts, an upper part in t~e *orm o~ a bo~v, such as
shown in ~ig.2, and a lower pax~ bearing such as shown a-t 8
in ~ig.2, connected scar~wise such as show~ at ~ to the
upper bow-shaped part. ~he heat e~change tubes 6 are s~cured
on the lateral sur~aces o~ the support elements 7 so that
they go around the sur~ace o~ the cooler 2 along a wa~e li~e
with a space ~1 o~ variable cross-seGtion being formed
between the sur~aces o~ the ~linders 3 and the heat exchange
tubes 6. ~he tube arrangement along a wave line and the
provision of a space having variable cross section pe~mits
the heat-trans~er area to be increased.
Mou~ted for axial rotation on the heat~exchange tubes
6 (Fig. 3) are heat-removing elements 10 made in the form
o~ plates ~rom high-temperature-resistant material and
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7 ~ 3
periodically brought into contact with the surfaces ol the
cylinders 3 of ~he cooler 2. Owing to the ~act that tl1e
tubes 6 are arranged along a wave line~ the heat-trans~er
axea is substantially increa~ed, thereby enabling greater
~mount o~ heat to be removed from the sur~aces of the cylin-
ders 3.
~ o e~lect cooling of the branch pipes 4 (~ig.l), the
apparatus o~ the invention is provided with a system o~
heat-removing tubes II, with the intertubular space being
~o~ less than one tim~ the tube diameter. Each tubé II has
one of i~s end ~ixed on a ring-shaped ~upport mem~er 12
mounted on the shell o~ the kiln I, the other end thereo~
being ~ixed on the la~t, as viewed in the direction away
from the kiln, support member 7. ~he sur~ace o~ the tubes II
is encompassed by screens 13. Moun~ed around the shell o~
the kiln I is an air li~e 1~ branched at 15 i~ the direction
o~ the discharge branch pipes 4~ ~he direction o~ air ~low
is indicated`in the drawing by arrow ~Bt~o The air line 14
is connected with a bla~-t ~an 16
Mounted around the cy].inders is an insulatin~ housin~
17. A ~low o~ hot air sucked out by the blast fan 16 ~rom
the space ~ormed between the housing 17 and the c~nders 3
is ~hen pass~d through piping 18 to be used ~or blasting or
pressure charging o~ the branch pipes 4 a~d c~linders ~ o~
the cooler 2~
The direction of hot air ~low is indicated in the draw
ing by arrow "C"~
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~ he apparatus according to the inven~ion ~or removir.g
he~t from the cylinders of the rotary kiln recuperator
cooler functions as ~ollows.
The heat radiated by the upper part o~ each cylinder ~
of the cooler 2 is ab~orbed by the sur~ace of the heat-e~chc~ge
tubes 6, whereas the heat radia~ed by the lower part of each
c~linder 3 is absorbed by the rotatable heat-removing ele~
ments 10.
When ~ound i~ the inter~paces betwee~ the cylinders 3
the eleme~ts 10, mounted for axial rotation on the hea~-
exchange tubes 6, undergo pendulum-like swinging movements
thereby taking up heat ~rom the hottest part o~ the cooler
and trans~er it by convection a~d radiation ~o the heat~
exchange tubes 6. ~hen, as the eleme~ts 10 per~orm their
next turning movement9 -they are brought into contact ~ith
the hot sur~ace of the cylinders ~ and trans~er heat to the
tubes 6, thus ~unctioning as the heat-conducting elementsO
~ o enable cooli~g o~ ~he discharge branch pipes 4 o~
the cooler 2 and to step up removal of heat from the cylinders
3, air is periodically supplied alt0rnati~ely to the discharge
branch pipes 4 and to the heat-removing elements 10. ~o
~acilitate this operation, the branch pipes 15 are mounted
o~ the air line 14 so as ~o face the discharge branch pipes
4 of the cooler 2. As ~he cooler rotates, air streams are
~lown out ~rom the branch pipe~ 15 to periodically blow o~
the branch pipe~ ~ and elemen~s 10.
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As a resultg ~he cylinders 3 are subjec-ted to blowing
giving off heat to be removed therefrom.
Air blowing is carri~d out by mean~ of the air ~an 16
~hich sucks in air from outside. I~ need be9 ~he system of
the air line 14 c~n ~unction on the basis o~ recirculation,
sucking in ~he air devoid o.~ heat given o~f to the heat-
exchan~e tubes 6~ Recirculation is ef~ected by means o~
intake pipas. In the regions where the design temperature
o~ the outside air is lower, ~or e~ample, than minus 30C,
the apparatu~ o~ ~he i~vention can be enclosed in the
housin~ 17.
It has been found that due to ~ixing o~ the heat-exchan-
ge tubes 6 on the bow-shaped support members 7 along wave
li~e, ~he heat-transfer area has been increased, as compared
to the prior-art apparatus, not less than 1~5 ~imesO
~ he support members 7 are dismountable together with
the heat-exc~ange tubes 6 owing to the fact that the tubes 6
are t*iiRrobe~ directl~ to the support member~ 7 and are con-
nected scar~wise, such as shown at 9, to the bearing base 80
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o~ .
