Process and apparatus for cleaning the door or door frame of a coke oven

A carriage is freely suspended, to be movable in all directions, from a cart movable along rails supported by a fixed coke guide car structure of a coke oven. The carriage has upper and lower drives which move grippers to grip the back of a door to be cleaned and to thus move the freely suspended carriage toward the door. Centering pieces on the carriage contact the edges of the door and center the carriage relative to the specific alignment of the door. The carriage carries a further drive which rotates spindles which cause cleaning instruments mounted thereon to move therealong to clean surfaces of the door.

BACKGROUND OF THE INVENTION 
The present invention relates to a process for cleaning the door or door 
frame of a coking furnace, and particularly to such a process wherein a 
carriage equipped with cleaning instruments is mounted on a coke guide car 
structure. The carriage is propelled towards the door or door frame, and 
after they have been aligned, the cleaning instruments are caused to act 
against the surfaces requiring cleaning. The present invention further 
relates to an apparatus with which to carry out the aforementioned 
process. 
The cleaning of coking oven doors is necessary, since the operation of 
coking furnaces leads to the formation of incrustations which have a 
deleterious effect on the furnace and which specifically can lead, among 
other things, to leakages around the door. For this reason, it is common 
practice to clean the coking oven doors after every discharge from the 
furnace chamber before reusing the furnace. The principle difficulties 
which are encountered in mechanical cleaning operations relate mainly to 
the fact that satisfactory cleaning requires small tolerances between the 
surfaces to be cleaned and the cleaning instruments, while at the same 
time the displacement of the door and the movement of the carriage or rig 
carrying the cleaning instruments requires large tolerances. 
The great height of the furnace door adds to the difficulties, as does the 
fact that the cleaning instruments must be applied with relatively great 
pressure in order to remove the crust formations. This pressure must not, 
however, be anywhere near great enough to cause deformation or other 
damage to the door or door frame elements. 
German DT-AS No. 1,147,914 describes a device for cleaning the edge seal of 
a furnace door wherein, in order to align the rig to any given door 
opening, the rig is freely suspended about a horizontal axis of rotation. 
In addition, compression springs are provided to act in the direction of 
the center of rotation and to produce an elastic mounting of the rig and 
an elastic counter-pressure where the rig and door stoppers join. In this 
system the arrangement between rig and door is an improvement over a 
rigidly mounted rig. However, there still remains the difficulty that the 
height of the axis of rotation relative to the door must be exactly 
predetermined, since otherwise the cleaning of the upper and lower edge 
seals of the door is impaired. Another disadvantage is due to the fact 
that the springs continuously exert pressure when, in fact, during the 
actual cleaning operation a rigid combination of door and rig is desired. 
German DT-OS No. 1,671,332 describes a device for cleaning a coking oven 
door wherein the rig carrying the cleaning instruments is mounted on a 
universal joint. This allows the rig to carry out light rocking movements, 
so that in the event of the door being tilted, the rig can adjust to the 
position of the coking oven door. 
In this system also, the position of the rotating axes of the universal 
joint relative to the door must be exactly predetermined. This is 
difficult to achieve, since the tolerances between the position of the 
door and the rig drive mechanisms can be determined only with the greatest 
difficulties. 
In all the existing systems and processes, it is disadvantageous that the 
rig for cleaning the coking furnace door must be driven or tracked against 
the door, and that there exists no direct connection between the carriage 
drive and the displaced or drafted door. 
SUMMARY OF THE INVENTION 
The object of the present invention is to provide a process and apparatus 
which assure that whatever the position of the door may be, the carriage 
with the cleaning instruments can be properly positioned so as to reach 
and uniformly contact the door and to retain this position during the 
cleaning operation. 
This object is achieved according to the present invention in that the 
approaching motion between the carriage and the door is carried out by 
means of at least one driving mechanism which is on the carriage and which 
engages the door and in that the carriage, in a first phase of the 
approaching motion towards the door, has freedom of movement in all 
directions. In a second phase of the approaching motion centering devices 
and grippers of the carriage center and grip the door. At the end of the 
approaching motion, the door and the carriage become rigidly joined by 
means of centering devices and grippers, as well as the drive mechanism 
itself. The same procedure can be applied in connection with cleaning the 
door frame of the door. 
By means of freely suspending the carriage, the latter can accommodate 
itself to the precise position of the door without the excessive 
tolerances between the respective positions of the carriage support and 
the door hoisting device causing a major problem. The centering and 
gripping devices ensure that the carriage assumes the proper position 
against the door. The drive mechanism operating between the door and the 
carriage assures that the carriage pulls itself against the door and 
remains connected to the door. Due to the fact that the carriage 
independently pulls itself towards the door, it is possible to use a 
simple control device and also to avoid the problem that shifting of the 
door after the approach of the carriage can lead to a displacement between 
the cleaning instruments and the door surfaces requiring cleaning. 
The process of the invention may be an automatic operation. 
In a preferred and specific embodiment of the apparatus of the invention, 
the door is gripped by devices located at the top and at the bottom of the 
door. In moving the carriage to the door, it is preferable that a drive 
mechanism causes the gripping devices to carry out swinging motions that 
reach behind and grip the door. The carriage is suspended by a cable and 
is attached to the drive mechanism that brings the carriage towards the 
door. The drive mechanisms cause the gripping devices to grip the door by 
means of a system of levers. The cable suspension of the carriage provides 
the advantage that the carriage, independent of the carriage mount, can 
easily adapt itself to any door position whenever the drive mechanism, by 
way of the lever system, pulls the carriage to the door. 
It is advantageous to attach the cable to the carriage mount by way of 
springs. This allows adjustment of the position of the carriage with 
respect to the door with only a small expenditure of energy. 
It is advantageous to connect the cable to a cart which runs on tracks 
attached to the coke guide car structure of the coke oven. This cart 
requires no individual drive and is pulled along the tracks whenever the 
cable is stressed or pulled by the drive mechanism.

DETAILED DESCRIPTION OF THE INVENTION 
Rigidly fixed adjacent a coke oven (not shown) is a coke guide car 
structure A. This structure is conventional, and thus only portions 
thereof are shown in FIGS. 2 and 5. Mounted above structure A are guide 
rails 1 along which is movable a cart 2. A carriage 4 is suspended from 
cart 2 via a flexible member such as cable 3. The carriage 4 supports a 
plurality of cleaning instruments or members 5 to 14. 
The carriage 4 is formed by a frame 19 of generally rectangular 
configuration and to which are attached brackets 20, 21 and 22 and 
bearings 23 to 30. Bearing pairs 23, 24 and 27, 28 respectively support 
vertical worm gear spindles 31 and 32. Bearing pairs 25, 26 and 29, 30 
respectively support horizontal worm gear spindles 33 and 34. An electric 
motor 35 is mounted on the bracket 20 and drives the threaded spindles 31 
through 34. For this purpose, adjacent ends of the threaded spindles are 
joined via meshing beveled gears. On the threaded spindle 31 are 
threadedly mounted the guide support members 36 to 39 which respectively 
support the cleaning instruments 5 to 8. On the threaded spindle 33 is 
threadedly mounted the guide support member 40 to which is attached the 
cleaning instrument 9. Along the threaded spindle 32 are threadedly 
mounted guide support members 41 through 44 which respectively support the 
cleaning instruments 10 to 13. The threaded spindle 34 has threadedly 
mounted thereon the guide support member 45 to which is attached the 
cleaning instrument 14. Each of the guide support members are movably 
mounted on longitudinally extending sides of a generally rectangular slide 
46 that extends along the frame 19, so that rotation of spindles 31 
through 34 produces respective longitudinal displacement movements of the 
cleaning tools. For purposes of simple adjustment, the cleaning tools are 
spaced along the spindles. 
The brackets 21 and 22 are cantilevered to frame 19 and respectively 
support electro-motors 47 and 48. The electric motor 47 operates an upper 
drive member 49, and electric motor 48 operates a lower drive member 50. 
Each of the drive members 49 and 50 include a threaded spindle 51, one end 
of which is coupled to the respective motor 47 or 48 via a universal joint 
52. The other end of each threaded spindle 51 carries a threaded coupling 
53 which is prevented from rotating by means of a guide brace 55. Rigidly 
connected to the coke guide car structure A are plates 56, each of which 
has an arcuate or curved slot 56a and a longitudinal slot 56b. Rod or 
roller 55a, connected to coupling 53 through brace 55, rides in slots 56b 
and is connected to arm 54 which carries a bolt 59 on which is mounted 
gripper or engaging element 57. A peg or rod 58 is attached to element 57 
and rides in arcuate slots 56a. Bolt 59 also rides in slots 56a. Depending 
on the direction of rotation of spindle 51 by drive motor 48, coupling 53 
is shifted to the right or left, as viewed in FIG. 5, and element 57 is 
lowered into a non-gripping position or raised in a gripping position. 
More specifically, movement of coupling 53 to the right moves element 57 
to the position shown in FIG. 5. However, movement of coupling 53 to the 
left causes element 57 to be raised, due to bolt 59 and rod 58 riding in 
slots 56a. 
Along the frame 19 of the carriage 4 are provided centering pieces 60 to 
65. Centering pieces 60, 61 and 63, 64 are provided for aligning the 
longitudinal sides of the door with the carriage. Centering between the 
upper and lower surfaces of the carriage and door is performed by the 
centering pieces 65 and 62, respectively. More particularly, three 
centering pieces, i.e., 60, 65 and 64, are located at the upper portion of 
the carriage, and three centering pieces, i.e., 61, 62 and 63, are located 
at the lower portion of the carriage. Each of the centering pieces 60 to 
65 has a curved alignment surface 66, as shown in FIG. 1 with regard to 
pieces 62 and 65, for facilitating centering. 
Frame 19 of carriage 4 may be provided with spacers 19a to space carriage 4 
from door 15 by a desired distance. Any suitable spacer structure may be 
employed. For instance, each spacer could be a pipe attached to frame 19. 
One or both ends of the pipe could be threaded to receive adjusting screws 
so that the spacing function could be adjustable. Preferably, the spacers 
are provided at the top and bottom portions of frame 19. Further, the 
spacers may be equipped with conventional switches so that when the door 
and carriage are desirably spaced, the respective motors 47 and 48 are 
shut off. Such switches could be conventional micro-switches or 
conventional ampere-consumption relays which would shut off the motors in 
response to increased ampere consumption if the motor continued to operate 
after the door abutted with the spacers. Other types of conventional 
switches could also be used. 
The frame 19 of the carriage 4 is equipped with bearing blocks or support 
members 67 and 68 which are connected, with a certain degree of free play, 
to a support 69 which is attached to cart 2. The free play is calculated 
to allow the carriage to adjust to all anticipated positions of the coke 
oven door and may be provided by various known mechanical expedients for 
obtaining free play between two interconnected members. For instance, 
members 67 and 68 may be attached to support 69 by means of rod-type 
connecting elements having a round cross-sectional configuration and 
fitting in recesses in members 67 and 68 or in support 69 having a 
non-round or non-circular configuration. Thus, free play between support 
69 and members 67 and 68 would be possible. 
Carriage 4 is supported by a cable 3 which has loops formed at opposite 
ends 70 and 71 thereof. The carriage 4 is suspended from the looped ends 
by means of carrying or reinforced eyelets 72 and 73 (see FIG. 2). The 
positioning of the cable 3 from cart 2 is shown in detail in FIG. 3. The 
cable is attached at a position between ends 70 and 71 to cart 2 by means 
of a supporter or supporting piece 74 which can be raised or lowered 
between guide jaws 75. The distance between supporter 74 and a plate 76 
can be adjusted by means of screws 77 which are threaded into supporter 74 
and which rest against plate 76. The plate 76 rests on first ends of 
compression springs 78, only one of which can be seen in FIG. 3. The other 
ends of compression springs 78 contact the cart 2. The compression springs 
take up the weight of the carriage 4 by way of cable 3, the supporting 
piece 74, the screws 77 and the plate 76. The intermediate height of the 
carriage 4 can be adjusted by means of the screws 77. 
FIG. 4 illustrates a specific arrangement or structure of any one of the 
cleaning instruments 5 to 14. The cleaning instrument has a scraping edge 
79 which scrapes or cleans the area between the door body 16, sealing 
members 18, and support bracket 80 of the door stopper 17. The scraping 
edge or member 79 is attached to a scraper holder 81 so as to be easily 
exchangeable. The scraper holder 81 is mounted on a carrier member 83 with 
a compression spring 82 therebetween. Carrier 83 is welded onto the 
corresponding support member 36 to 45. The carrier 83 and the scraper 
holder 81 extend at an angle of approximately 60.degree. from the plane of 
the carriage frame 19 to the door frame 16. 
The operation of the door cleaning process described above is as follows. 
After the door 15 has been lifted out of its door frame along the coke oven 
chamber by means of a conventional hoist and has been turned around its 
longitudinal axis by 90.degree., it comes to rest at the position shown in 
FIG. 1. 
In order to clean the door, the cleaning instruments 5 to 14 must be moved 
towards the door, and thus the electric motors 47 and 48 are switched on. 
Starting from the position shown in FIG. 1, motors 47 and 48 cause the 
initial motion of the threaded spindles 51 to move the respective grippers 
57 to turn in the direction of the upper and lower door edges, 
respectively. This causes the door to be engaged from behind, or from the 
right as shown in FIG. 1, by the grippers 57. As soon as the grippers 57 
make contact with the door, the carriage 4 begins to move towards the door 
15 due to the rotation of the threaded spindles 51. The cart 2 follows 
this motion along rails 1 due to blocks 67 and 68 and support 69. 
During this approaching movement, the door edges come in contact with the 
centering surfaces 66 of the centering pieces 60 to 65, and the position 
of carriage 4 will thus be adjusted relative to any given door position. 
The connection between the blocks 67 and 68 and support 69, as well as 
universal joints 52, is so designed as to allow in all cases sufficient 
play to allow this adjustment. If major deviations of the angular position 
of the door in the direction of the height of the door are to be 
encountered, then a large amount of play can be calculated and provided 
accordingly. 
By suspending the carriage 4 from the cable 3, it becomes possible for the 
carriage 4 to freely pull itself towards the door 15 in all directions of 
motion. Angular displacements of the door around the longitudinal axis 
thereof as well as angular displacements around the transverse axis 
thereof can be compensated for by means of this cable type suspension. The 
mounting of the cable 3 via the compression springs 78 allows for the 
adaptation of the carriage 4 to deviations in the position of the door 
with very slight expenditure of power. 
As soon as the carriage 4 has been brought, by the respective grippers 57, 
to the proper distance from the door 15, at the top or at the bottom 
thereof, then the respective upper or lower motor is switched off. The 
spacing between the final positions of the carriage and door is determined 
by respective upper or lower spacers 19a attached to the carriage. The 
other motor 47 or 48 is then switched off when the respective gripper has 
achieved the proper spacing between the door and the carriage. At that 
point, the threaded spindles 31 to 34 that carry the cleaning instruments 
5 to 14 will rest parallel to the door surfaces requiring cleaning, and 
the cleaning instruments 5 to 14 will all contact the door surfaces to be 
cleaned with equal pressure. This condition is assured by the fact that 
the carriage 4 is firmly clutched to the door by means of the centering 
pieces 60 to 65. 
The motor 35 is then switched on and rotates the threaded spindle 31, which 
in turn drives the threaded spindle 33, which drives the threaded spindle 
32, which drives the threaded spindle 34. As a result, the cleaning 
instruments are synchronously moved in a desired manner. For example, the 
cleaning instruments 5 to 8 move upwards, the cleaning instrument 9 moves 
towards the left, the cleaning instruments 10 to 13 move downward, and the 
cleaning instrument 14 moves to the right, as shown in FIG. 2. The 
compression springs 82, by which the cleaning instruments are mounted on 
the respective support members, ensure that even limited slippage or 
dislocations of the surfaces requiring cleaning can be compensated for. 
The pitch of the worm portions of the threaded spindles 31 to 34 and the 
ratios of the teeth of the bevel gears joining the spindles are designed 
to provide that all of the cleaning instruments reach the ends of the 
respective surfaces to be cleaned at the same time. 
In the case of additional surfaces requiring cleaning by the cleaning 
instruments, it is possible to modify the structure of the cleaning 
instrumentation accordingly. 
After the completion of the cleaning process, the motor 35 is switched off, 
e.g. automatically. The motors 47 and 48 are then switched on in the 
opposite direction from that described above. In practice, the power 
required to overcome the resistance of the bolts 59 of the grippers 57 in 
the slots 56a is less than the power needed to release the centering 
pieces 60 to 65 from the door 15. Accordingly, the grippers 57 will 
release the door first. Subsequently, additional rotation of the spindles 
51 will cause the carriage 4 to be pushed away from the door while 
simultaneously taking along the cart 2. The carriage 4 moves away from the 
door until it reaches its initial starting position. The door, which has 
been cleaned along its right, left, upper and lower sealing edges, can 
then be returned into the door frame by means of the hoisting device. 
In the above described installation, it is particularly advantageous that 
the cable, which is mounted by means of compression springs 78, allows the 
carriage 4 to move absolutely free. The carriage can thus, with a minimum 
of energy requirements, be moved in any necessary direction. Accordingly, 
even if the door has been subjected to a major displacement, it will be 
possible to have the cleaning instruments perform a parallel approach to 
the door edges and to assure equal contact pressure by the cleaning 
instruments on the respective surfaces to be cleaned. 
In place of the electro-motor drives for the cleaning instruments and for 
the grippers, it is possible to provide other conventional drives, such as 
hydraulic drives. 
The above described process and apparatus can also be employed to clean the 
door frame of a coke oven. The cleaning of a door frame is actually 
simpler than the cleaning of a door, since there is no need to account for 
gaps or tolerances caused by the door hoisting machinery. 
It will be apparent that various modifications may be made to the above 
specifically described procedure and structural arrangement without 
departing from the scope of the invention.