GB2051857A

GB2051857A - Coke oven door lifting mechanism

Info

Publication number: GB2051857A
Application number: GB8021963A
Authority: GB
Original assignee: Hartung Kuhn and Co Maschinenfabrik GmbH
Current assignee: Hartung Kuhn and Co Maschinenfabrik GmbH
Priority date: 1979-07-05
Filing date: 1980-07-04
Publication date: 1981-01-21
Also published as: FR2460988A1; DE2927236C2; IT1209434B; GB2051857B; FR2460988B3; IT8068061A0; DE2927236A1

Abstract

A lifting mechanism (A) for the feed door of a horizontal chamber coke oven can be tilted at its upper end about a horizontal shaft (16), which is parallel to the door opening (2) of an oven chamber (1), at an angle support (14), which can be moved to and fro in the direction of the oven chamber (1), by means of an hydraulic piston and cylinder assembly (17) the movement of which is controlled by a bidirectional counter (21) which counts a predetermined number of pulses produced by a pulse generator (22) in dependence on the travel of the assembly (17). The count of the counter (21) is proportional to the tilt position of the tilting part (13) and thus to the actual inclination of the door opening (2). Before the feed door (3) is reinserted into the door opening (2), the hydraulic cylinder (17) is moved out and the bidirectional counter (21) counts down until the initial count corresponding to the actual inclination of the door opening 2 has been reached again. <IMAGE>

Description

SPECIFICATION Lifting mechanism for tEle p feed door of a horizontal chamber coke oven The present invention relates to a lifting mechanism for the feed door of a horizontal chamber coke oven.

Coke oven feed doors with good insulating action engage the door opening of the oven chamber as tightly as possible. Since they are not joined to the coke oven with hinges, they are lifted out of the oven chamber and reinserted into it by means of a lifting mechanism and preferably by means of an automatic lifting mechanism. In this arrangement, the lifting mechanism is not permanently joined to the door but is moved up to the door and coupled to it only for the purpose of opening the door, for which purpose the lifting mechanisrr is provided with lifting claws which engage corresponding thrust bearings or bearing blocks at the feed door where they are supported.

The lifting mechanism is constructed in such a manner that it can raise or lower the feed door not only in the direction of the longitudinal axis of the oven chamber but also between a lower and an upper position and, in addition, the door which has been pulled out of the door opening is customarily also conveyed by means of the lifting mechanism into a cleaning position, the height of which can differ from that of the door opening.

Lifting mechanisms of this type of construction have been disclosed with different details of construction and of control engineering (for example, see German Patent No. 750,211, German Auslegeschrift No. 2,329,990 and German Auslegeschrift No. 2,720,469).

Until now, however, the fact that, although the cleaning mechanism is generally always vertical, the door opening can have an inclination which deviates from the vertical, has not been considered of importance. The feed door, in turn, is inserted into such an inclined door opening also in an inclined position. The inclination can vary between the individual oven chambers of a coke oven battery. This inclination has been considered negligible, apparently because of the comparatively small degree of misalignment, which can be up to about 100 mm with a feed door height of the order of 4 to 6 m, depending on the age of a coke oven battery.Also, of course, it is of no importance with some of the known lifting mechanisms, particularly when the feed door is reinserted into the door opening, since the process of insertion takes place under elastic pretensioning which automatically produces appropriate compensation.

It is a disadvantage, however, that during reinsertion of the door into the misaligned door frame the sealing strips of the feed door, which is suspended essentially vertically at the lifting claws, meet the sealing area of the door frame unilaterally, that is to say only at one place, so that a high specific pressure occurs at this point. Due to the angular deviation between the door frame and the feed door, the lifting claws engage the bearing blocks in some cases very unevenly and jerkily. The above mentioned operating conditions lead not only zo the door frame being damaged but also to the sudden escape of harmful dustcarrying gases from the oven chamber at an undesirable time, namely before the feed door is taken out of the door opening.

For these reasons, it is the object of the present invention to provide a lifting mechanism which takes into consideration the respective actual position of the door opening, both during the lifting out and during the reinsertion of the feed door, with simple constructional and control engineering effort.

According to the present invention there is provided a lifting mechanism for the feed door of a horizontal chamber coke oven, the mechanism comprising: means for moving the mechanism horizontally towards and away from the feed door; lifting claws for engaging bearing blocks on the feed door, the engagement taking place when the lifting mechanism has been moved towards the feed door; means for tilting the mechanism about an axis parallel to the door opening; and a lifting control system for Gifting the feed door on detecting the engagement of the lifting claws, moving the door horizontally out of the door opening and into a cleaning position and, after the door has been cleaned, moving the door back into the door opening, the lifting control system controlling the lifting and tilting movement of the lifting mechanism such that, during the process of lifting the feed door and reinserting the same the lifting mechanism has an inclination which corresponds to the actual inclination of the door opening.

Preferably, the tilting and lifting movement of the lifting mechanism is controllable by the lifting control system such that the lifting mechanism is vertical in the cleaning position.

The lifting mechanism is preferably tiltable about a horizontal axis.

The lifting mechanism may be tiltable about a shaft located at the upper portion of a support carrying the lifting claws, the tilting movement being perFormed by means of a lifting drive system which engages the lower portion of the support.

The lifting drive system may comprise an hydraulic piston and cylinder assembly. Preferably, the hydraulic piston and cylinder assembly includes a pressure relief valve for releasing hydraulic fluid to permit tilting-back of the lifting mechanism.

Preferably, the force of the lifting drive system is less than that of a drive system for producing the horizontal movement of the lifting mechanism.

The lifting mechanism may include means for tilting the lifting mechanism in accordance with the maximum possible inclination of a door opening prior to moving the lifting mechanism horizontally towards the oven chamber, the tilt of the lifting mechanism being adjusted to the actual inclination of the feed door as the lifting mechanism is moved horizontally.

Preferably, the lifting mechanism includes a memory device for storing a pulse count corresponding to the respective actual inclination of the door opening. The memory device may comprise a bidirectional counter which, starting from an initial value, counts up pulses corresponding to the travel between the respective actual inclination and the vertical corresponding to the cleaning position, and counts the pulses down to the initial value when the feed door is reinserted. The initial count corresponding to the actual inclination may have the value zero.

Thus, it is possible for the sealing strip of the feed door to meet the sealing area of a door frame substantially simultaneously over its whole periphery so that no further manipulations are required for the sealing strip to rest completely against the door frame. In addition, the feed door may be lifted out of the door frame at the exact angle which the latter assumes with respect to the vertical. As mentioned, the feed door may also be reinserted into the door frame exactly at this angle corresponding to that of the door frame, whereas the feed door can be moved into a door cleaning mechanism in the vertical position which is ideal for door cleaning. In addition, if a feed door is exchanged for another one, the latter can be reinserted into the door opening in the inclined position or inclination required for the respective door opening.

For a better understanding of the present invention and to show more clearly how it may be carried into effect reference will now be made, by way of example, to the accompanying drawing which shows a diagrammatic side view of one embodiment of a lifting mechanism according to the present invention, with a feed door which has been pulled out of the oven chamber of a coke oven and which is already in the vertical position.

The figure shows an oven chamber 1 of a coke oven provided with several horizontal chambers, the door opening 2 of which can be closed with the aid of a feed door 3 which is not hinged at the oven chamber 1. The feed door 3 mates with the oven chamber 1 and can be raised by means of a lifting mechanism A from its central position with respect to the door opening 2 and pulled out or pushed in and lowered.

The lifting mechanism A is mounted on a carriage 7 which is provided with rollers 4 and which can be moved by means of a drive device, for example an hydraulic piston and cylinder assembly 5, along rails 6 in the direction of the longitudinal axis of the oven chamber 1. The feed door 3 carries at its outside at least two bearing blocks 8 which are spaced apart vertically by means of which it is supported on claws 9 of a support 10 which can be displaced substantially vertically by means of rollers 11 along rails 12 of a tilting part 1 3. For this purpose, the support 10 can be moved by a drive system (not shown) such as an hydraulic piston and cylinder assembly.

The carriage 7 is connected integrally with an angle support 14, at a horizontally projecting part 1 5 of which the tilting part 13 is mounted suspended via a horizontal tilting shaft 1 6 which extends parallel to the oven chamber 1, the tilting part 13 being tiltable about the shaft 1 6. At the vertically opposite end of the tilting part 13 one end of an hydraulic piston and cylinder assembly 17 is pivoted, the other end of which is pivoted at that end of the angle support 14 which is opposite the horizontally projecting part 1 5, the force of the assembly 1 7 preferably being less than that of the assembly 5.

As shown in the figure on an exaggerated scale the door opening 2 of the oven chamber 1 can be inclined with respect to the vertical in such a manner that a horizontal distance a exists between the upper and lower ends. In older coke oven batteries with oven chambers of a height of 4 to 6 m, this distance can be of the order of 100 mm and depends not only on the manufacturing tolerances of the coke oven but also on changes during the operation of the coke oven. The distance a can be different from oven chamber to oven chamber, even within one coke oven. In contrast to this, a cleaning mechanism (not shown) for the feed door 3, into which the feed door 3 is moved by means of the lifting mechanism after being lifted out of the door opening 2, is always vertical.

On the one hand, it is desirable to move the feed door 3 always vertically into the vertical cleaning mechanism and, on the other hand, it is desirable to lift the feed door 3 out of the door opening 2, and to reinsert it into the latter, in accordance with its respective inclination to the door opening 2.

According to the illustrated embodiment of the present invention, this is done in such a manner that firstly the tilting part 1 3 is brought into its inclined position, which corresponds at least to the greatest possible inclination of the door opening 2, that is to say at least to the greatest possible distance a, by extending the hydraulic piston and cylinder assembly 1 7. Then the lifting mechanism is moved in the direction of the feed door 3, which is still inserted in the door opening 2, by extending the hydraulic piston and cylinder assembly 5. The portion of the tilting part 13 projecting the farthest is the one which first comes to rest against the feed door 3.Then the hydraulic piston and cylinder assembly 1 7 is retracted against the force of the hydraulic piston and cylinder assembly 5 until the tilting part 1 3 has reached the actual inclination of the inserted feed door 3, that is to say until it is substantially parallel to it. The hydraulic piston and cylinder assembly 1 7 is retracted by, for example, bleeding off the hydraulic fluid via a pressure relief valve. The position of the hydraulic piston and cylinder assembly 1 7 which has now been reached is stored, for example in the manner explained below. The feed door 3 is lifted out of the door opening 2 by moving the support 10 upwards and then moving the carriage 7 back. Before moving into the cleaning mechanism, the hydraulic piston and cylinder assembly 1 7 is retracted until the tilting part 1 3 is arranged absolutely vertically and thus in the optimum position for the cleaning mechanism. This inward movement can be triggered by switching a solenoid valve (not shown) in the fluid circuit of the hydraulic piston and cylinder assembly 1 7 accordingly.The tilting part 13 is adjusted vertically by suspending a plumb bob from a pendulum, completely retracting the hydraulic piston and cylinder assembly 1 7 and then pushing the cylinder back via a bushing and via a spindle until the piston has reached the end position at the bottom of the cylinder, os that the vertical position of the tilting part 1 3 is and remains fixed by this fixed point.

The insertion of the cleaned feed door 3 into the (also cleaned) door opening 2 is carried out in the reverse manner. For this purpose, particularly the hydraulic piston and cylinder assembly 1 7 is extended again into the stored position in which the inclination of the feed door 3 corresponds to the inclination of the door opening 2, after which the feed door 3 is then reinserted into the door opening 2 in the usual manner.

Naturally, it is also possible to tilt the tilting part 13 about a horizontal axis which is parallel to the tilting shaft 1 6 and which is arranged in another position in the vertical direction of the tilting part 13, and the tilting movement can also be carried out by a different drive system. It is essential that the position of the tilting part 13 corresponding to the actual inclination of the door opening 2 is stored in some manner and that this stored position is used again when the feed door 3 is reinserted into the door opening 2.

In addition, the principle of the invention can be used not only with a lifting mechanism for the feed door but in the same manner also for a door frame cleaning mechanism.

It is a particular advantage, especiaily with a digitally-controlled lifting operation, for example according to German Auslegeschrift No.

2,720,469, if here, too, the control function is handled digitally.

The movement of the tilting part 13 while it is being tilted by means of the hydraulic piston and cylinder assembly 1 7 is controlled by a bidirectional counter 21 which counts pulses generated by a pulse generator 22 as a function of the travel of the hydraulic piston and cylinder assembly 1 7 and thus of the tilting movement of the tilting part 1 3. In the present case the pulse generator is provided with a solenoid switch 23 which responds to field changes of a magnet 26 coupled via a toothed wheel 24 to a rack 25.In this arrangement, the rack 25 is connected integrally with the tilting part 13, preferably in the area of its largest deflection, that is to say near the hydraulic piston and cylinder assembly 1 7. The pulse generator 22 emits a predetermined number of pulses per unit length of the travel of the hydraulic piston and cylinder assembly 1 7. Thus the count of the bidirectional counter 21 is proportional to the tilt of the tilting part 1 3 and thus to the actual inclination of the door opening 2 or to the distance a.

It is a particular advantage if the aforementioned counting operation of the bidirectional counter 21 is triggered when the tilting part 13 has the same inclination as the actual inclination of the door opening 2, which can take place, for example, simultaneously with the switching-on of the aforementioned solenoid valve. The bidirectional counter then counts up until the tilting part 13, with the feed door 3 which has been lifted out, has been tilted into the vertical position. Before the feed door 3 is reinserted into the door opening 2, the hydraulic piston and cylinder assembly 1 7 is moved out against and the bidirectional counter simultaneously counts down until the initial count, at which the counting-up has been triggered and which corresponds to the actual inclination of the door opening 2, has been reached again.This intial value can be the value 0.

When this initial count has been reached again, the hydraulic piston and cylinder assembly 1 7 is stopped and the feed door 3 is reinserted by means of the hydraulic cylinder 5 and the lifting mechanism of the support 10 into the door opening 2 in a manner known in itself but tilted according to the actual inclination of the door opening 2.

Of course, the lifting mechanism according to the invention can be used not only in those cases in which, as in the present illustrative embodiment, the port-end projects with respect to the front edge of the oven bottom of an oven chamber, but also in those cases, even if they generally occur less frequently, in which the portend is spaced a smaller distance away from the vertical centre plane of the coke oven battery than is the front edge of the oven bottom. In each case an even specific surface pressure is achieved when the sealing strip of the feed door meets the sealing area of the door frame and in this way unilateral stresses and high maintenance expenditure are avoided.

Claims

1. A lifting mechanism for the feed door of a horizontal chamber coke oven, the mechanism comprising: means for moving the mechanism horizontally towards and away from the feed door; lifting claws for engaging bearing blocks on the feed door, the engagement taking place when the lifting mechanism has been moved towards the feed door; means for tilting the mechanism about an axis parallel to the door opening; and a lifting control system for lifting the feed door on detecting the engagement of the lifting claws, moving the door horizontally out of the door opening and into a cleaning position and, after the door has been cleaned, moving the door back into the door opening, the lifting control system controlling the lifting and tilting movement of the lifting mechanism such that, during the process of lifting the feed door and reinserting the same, the lifting mechanism has an inclination which corresponds to the actual inclination of the door opening.

2. A lifting mechanism as claimed in claim 1, wherein the tilting and lifting movement of the lifting mechanism is controllable by the lifting control system such that the lifting mechanism is vertical in the cleaning position.

3. A lifting mechanism as claimed in claim 1 or 2, wherein the lifting mechanism is tiltable about a horizontal axis.

4. A lifting mechanism as claimed in claim 3, wherein the lifting mechanism is tiltable about a shaft located at the upper portion of a support carrying the lifting claws, the tilting movement being performed by means of a lifting drive system which engages the lower portion of the support.

5. A lifting mechanism as claimed in claim 4, wherein the lifting drive system comprises an hydraulic piston and cylinder assembly.

6. A lifting mechanism as claimed in claim 5, wherein the hydraulic piston and cylinder assembly includes a pressure reiief valve for reieasing hydraulic fluid to permit tilting back of the lifting mechanism.

7. A lifting mechanism as claimed in claim 4, 5 or 6, wherein the force of the lifting drive system is less than that of a drive system for producing the horizontal movement of the lifting mechanism.

8. A lifting mechanism as claimed in any preceding claim and including means for tilting the lifting mechanism in accordance with the maximum possible inclination of a door opening prior to moving the lifting mechanism horizontally towards the oven chamber, the tilt of the lifting mechanism being adjusted to the actual inclination of the feed door as the lifting mechanism is moved horizontally.

9. A lifting mechanism as claimed in any preceding claim and including a memory device for storing a pulse count corresponding to the respective actual inclination of the door opening.

10. A lifting mechanism as claimed in claim 9, wherein the memory device comprises a bidirectional counter which, starting from an initial value, counts up pulses corresponding to the travel between the respective actual inclination and the vertical corresponding to the cleaning position, and counts the pulses down to the intitial value when the feed door is reinserted.

11. A lifting mechanism as claimed in claim 10, wherein the initial count corresponding to the actual inclination has the value zero,

12. A lifting mechanism for the feed door of a horizontal chamber coke oven substantially as hereinbefore described with reference to, and as shown in, the accompanying drawing.