U.S. patent number 3,923,450 [Application Number 05/473,575] was granted by the patent office on 1975-12-02 for rotary kiln provided with seal mechanism.
This patent grant is currently assigned to Kobe Steel Ltd.. Invention is credited to Seiichi Hirano, Yasokazu Ikuno, Kimio Inoue, Tamiharu Sakai.
United States Patent |
3,923,450 |
Inoue , et al. |
December 2, 1975 |
Rotary kiln provided with seal mechanism
Abstract
A so-called rotary kiln in which a material is continuously
heated by means of a rotatably supported cylinder is provided with
a seal mechanism for blocking the outer air from the interior of
the cylinder, hereinafter referred to as the "rotary kiln proper".
The seal mechanism for the rotary kiln undergoes various adverse
conditions involved inherently in the operation of the rotary kiln,
such as vibration in the peripheral portion of the rotary kiln
proper during rotation, thermal deformation, thermal elongation and
contraction of the rotary kiln proper, continuous operation at high
temperatures and the like. In the rotary kiln of this invention,
improved air-tightness can be maintained stably even under such
conditions, principally being achieved by the provision of an
elastic member supporting the weight of a hood independently of the
rotary kiln proper for preventing a deflected load from being
imposed on the seal mechanism, and preferably, a specific seal
mechanism especially fit for such an elastic member is
employed.
Inventors: |
Inoue; Kimio (Kobe,
JA), Hirano; Seiichi (Kobe, JA), Sakai;
Tamiharu (Kobe, JA), Ikuno; Yasokazu (Osaka,
JA) |
Assignee: |
Kobe Steel Ltd. (Kobe,
JA)
|
Family
ID: |
13257187 |
Appl.
No.: |
05/473,575 |
Filed: |
May 28, 1974 |
Foreign Application Priority Data
|
|
|
|
|
May 31, 1973 [JA] |
|
|
48-64399 |
|
Current U.S.
Class: |
432/115;
34/242 |
Current CPC
Class: |
F27B
7/24 (20130101) |
Current International
Class: |
F27B
7/20 (20060101); F27B 7/24 (20060101); F27B
007/024 () |
Field of
Search: |
;432/115,111
;34/242 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Camby; John J.
Attorney, Agent or Firm: Oblon, Fisher, Spivak, McClelland
& Maier
Claims
What is claimed as new and intended to be covered by Letters Patent
is:
1. A rotary kiln provided with a seal mechanism, comprising:
a rotary kiln proper;
a hood covering one end portion of said rotary kiln proper;
a seal mechanism providing a seal between said rotary kiln proper
and said hood which has metal rings, packings, and means for
lubricating the sliding faces of said metal rings and packings;
an elastic means for supporting the weight of the hood
independently of said rotary kiln proper; and
a position-adjusting means connected to said elastic means for
vertically adjusting the hood supported thereby.
2. The rotary kiln set forth in claim 1 which further
comprises:
a moving truck supporting said elastic means for moving said
elastic means in a direction parallel to the axial direction of
said rotary kiln proper.
3. The rotary kiln set forth in claim 1, wherein said hood is
suspended through said elastic means and said position-adjusting
means.
4. The rotary kiln set forth in claim 1, wherein said metal rings
and packing are arranged alternately.
Description
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates generally to rotary kilns in which a
material is continuously heated by means of a rotatably supported
cylinder, and more particularly to an improved rotary kiln having a
seal mechanism for providing a greater degree of air tightness of
the cylinder than former kilns possessed.
Rotary kilns of the type characterized herein are broadly employed
as effective heating kilns for the burning of cement and the
calcination of lime and the like. In such rotary kilns, it is
generally unnecessary to attain complete interception of the air
currents from the interior of the kiln unless special articles or
materials are being heat-treated therein. However, when such rotary
kilns are used for the preparation of reduced pellets and in the
thermal decomposition treatment of wastes, such as plastic and
rubber wastes, it is necessary to completely block the outer air
from the interior of the kiln proper by means of a seal mechanism
in order to prevent the oxidation of such reduced pellets, the
leakage of resulting gases or oils and the occurrence of an
explosion which might be caused by the incorporation of air.
Various improvements have been made on the seal mechanism in
connection with rotary kilns in which air-tightness should be
attained. In the case where such sealing is effected between the
rotary kiln proper and a fixing member, because of poor rotation
precision of the peripheral portion of the rotary kiln or thermal
deformation and thermal elongation or contraction of the rotary
kiln per se, a deflected load is discontinuously imposed on the
sliding face of the seal mechanism. Further, since a non-metallic
material constituting this sliding face is subjected to high
temperatures during the operation, even if improved seal mechanisms
are employed, they are readily destroyed in a short span of time.
Accordingly, no rotary kiln that can be operated stably and
continuously for a long period of time is now available.
Especially, there are no rotary kilns now available having a great
diameter rotary kiln proper in which a good seal can be attained
stably when the operation is continued for a long period of
time.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to
provide a rotary kiln which can overcome the former problems
characterized herein which are encountered in the conventional
rotary kilns and in which an improved seal can be attained stably
for a long duration.
Another object of the present invention is to provide a rotary kiln
in which there is no deflected load discontinuously imposed on the
seal mechanism of the kiln.
Still another object of the present invention is to provide a
rotary kiln in which a mechanical seal per se is so disposed that
no deflected load is imposed thereon, especially on a packing
thereof composed of a non-metallic material.
A further object of the present invention is to provide a rotary
kiln in which thermal deformation and thermal elongation and
contraction of the rotary kiln proper do not adversely affect the
seal mechanism of the device.
The foregoing and other objects are achieved according to the
present invention through the provision of a rotary kiln which is
characterized by a rotary kiln proper, a hood covering the end
portion of the rotary kiln proper, a seal mechanism providing a
seal between the rotary kiln and the hood, and an elastic member
supporting the weight of the hood separately from the weight of the
rotary kiln proper.
In the rotary kiln of the invention being constructed according to
the specific teachings thereof, even if the precision of the
rotation of the rotary kiln proper is poor at its peripheral
portion, the hood follows the rotary kiln proper during such
rotation and it is kept in the state of floating on the rotary kiln
proper regardless of the vertical load, so that a deflected load is
prevented from being imposed on the seal mechanism.
In a preferred embodiment of the invention, a metal ring is
provided in the seal mechanism and the elastic member is disposed
so that it can move in the direction parallel with the axial
direction of the rotary kiln proper. In this embodiment the
intended seal can be attained more effectively. More specifically,
the metal ring improves the ability of the hood to follow after the
rotary kiln and protects the non-metallic material of the seal
mechanism. Further, the movement of the elastic member results in
an absorption of the thermal elongation or contraction of the
rotary kiln proper in the axial direction, and therefore, the
stability of the seal mechanism is improved.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects features and attendant advantages of the
present invention will be more fully appreciated as the same
becomes better understood from the following detailed description
when considered in connection with the accompanying drawings, in
which like reference numerals designate like or corresponding parts
in the several views, and wherein:
FIG. 1 is a partial side view illustrating one embodiment of a
rotary kiln constructed according to the present invention;
FIG. 2 is a partial side view illustrating another embodiment of a
rotary kiln also constructed according to the teachings of the
present invention; and
FIG. 3 is a partial sectional view illustrating an example of a
seal mechanism to be used in the rotary kiln of the present
invention and contructed according to the teachings thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The rotary kiln of the present invention may be either the internal
heating type or the external heating type. In the accompanying
drawing, the invention is illustrated by reference to embodiments
concerning an external heating type rotary kiln to be used as an
apparatus for thermally decomposing plastic or rubber wastes and
for recovering oil or gaseous fuel, or useful materials such as
carbides and the like.
Referring now to the drawings, and more particularly to FIGS. 1 and
2, a rotary kiln proper 1 is shown being rotatably supported by a
roller 21 and a hood 8 is disposed to cover an end portion of the
rotary kiln proper. As is illustrated in FIG. 3, a seal mechanism
for providing a seal between the rotary kiln proper 1 and the hood
8 is formed from a double-cylinder sleeve 2 fitted integrally by
soldering or the like to the end portion of the rotary kiln proper
1, a plurality of ring-like packings 3, shown as being four in
number, mounted on the periphery of the outer cylinder wall, and a
plurality of corresponding metal rings 4, shown as being five in
number, being alternately arranged with the packing 3 on the
double-cylinder sleeve 2. These ring-like packings 3 and the metal
rings 4 are secured within a ring member 5 fitted to the hood 8 by
means of a clamping member 6 and a securing bolt 7 for adjusting
the force of the binding packings 3. A projection 9 and a control
metal fitting 10 are mounted between the hood 8 and the sleeve 2,
respectively, so that the hood 8, the ring member 5, the metal
rings 4 and the packings 3 can move along with any axial movement
of the rotary kiln proper 1 which may be caused by the thermal
expansion thereof. A grease nipple 12 is mounted on the ring member
5 and a lubricant, such as a heat-resistant grease, is fed
therethrough on the sliding surface between the packings 3 and the
metal rings 4 and the sleeve 2.
In the embodiment shown in FIG. 1, the hood 8 is shown being
supported independently from the rotary kiln proper 1 through an
elastic or resilient member composed of a plurality of springs 22,
a plurality of position-adjusting members 23 disposed in series
with the elastic member and a moving truck 24 carrying the springs
22 and the position-adjusting members 23.
In the embodiment shown in FIG. 2, the hood 8 is supported through
a spring 25, apposition-adjusting member 26 and a chain 27, and the
hood 8 is likewise supported independently from the rotary kiln
proper 1.
In both embodiments, it can be seen readily from the drawings that
the position-adjusting members may take the form of threaded bolts
projecting through a plate and having nuts threadably secured on
one side of the plate for varying the projection of the bolts
through the plate, whereby the vertical disposition of the hood may
be adjusted readily.
In the rotary kiln of this invention having such structure as
described herein, even when the rotary kiln proper 1 is shaken
through its rotation and the sliding face of the seal mechanism is
displaced by such shaking of the rotary kiln proper 1, the hood 8
follows the rotary kiln proper 1 without causing any deflected load
on the sliding surface, and a good seal can thereby be attained
stably for a long period of time. In order to further improve the
followability of the hood 8 after the rotary kiln proper 1, the
metal rings 4 can be provided in the seal mechanism. By provision
of these metal rings 4, it is possible to prevent the deflected
wearing of the packings 3. More specifically, if either the
position-adjusting member 23 or 26 is so regulated that the weight
of the seal mechanism and the hood 8, including the ring member 5,
is well balanced with the supporting force of the respective
elastic member 22 or 25 when the hood 8 is at a proper position,
then during the rotation of the rotary kiln proper 1, the hood 8
can easily follow the rotary kiln proper 1 with a very small force
and the force for supporting the structural members, such as the
rotary kiln proper 1, the hood 8 and the like, is not transmitted
through the sliding surface to the seal mechanism. Further, if the
above-mentioned metal rings 4 are employed, even the small force
indicated herein is not imposed on the packings 3 in a deflected
manner, and the sliding face or surface of the seal mechanism can
be maintained in good condition.
Moreover, since the hood 8 is so disposed that it can move in the
direction parallel to the axis of the rotary kiln proper 1, it is
not at all influenced by thermal elongation or contraction of the
rotary kiln proper 1. Namely, a good seal can therefore be attained
stably without changing the relative positions of the sleeve 2 and
the seal mechanism.
Obviously many modifications and variations of the present
invention are possible in light of these teachings. It is therefore
to be understood that within the scope of the appended claims, the
invention may be practiced otherwise than as specifically described
herein.
* * * * *