Patent Application
20100025217
This invention relates to a device and a method for supplying combustion air for the combustion of coking gas in cokemaking chambers of coke ovens built in flat-type construction and arranged as a battery of coke ovens for the so-called non-recovery or heat-recovery process. This device at least comprises a vent port for each cokemaking chamber, said vent port extending through the relevant coke oven door or its wall surrounding it, as well as vent ports for supplying secondary air into the heating flues. A freely-supported locking element is provided for each vent port.
All locking elements are mechanically connected to at least one adjusting element controlled and driven from a central point. The adjusting element continuously actuates the locking elements depending on the demand for combustion air in the cokemaking chamber. The mechanical connection of each individual locking element with the central adjusting element can be effected separately, wherein especially the starting position of each individual locking element at the beginning of the cokemaking process of the pertaining cokemaking chamber can be adjusted independently of the other locking elements of the adjacent cokemaking chambers.
Heating of heat-recovery ovens is usually performed by combustion of gas evolving on cokemaking. Combustion is controlled in such a manner that part of the gas above the coal charge burns off with primary air in the oven chamber. This partly burnt gas is fed through channels that are also designated as “downcomers” to the heating flues in the oven chamber sole and completely burnt there by the addition of further combustion air, which is called secondary air.
In this way, heat is directly supplied from the top and indirectly from the bottom to the coal charge, thus taking a positive impact on the coking rate and, thereby, on the performance rate of coke ovens. To execute the method it is required to exactly rate and variably control the supplied primary and secondary air throughout the carbonisation time that may take up to 20 to 96 hours. Heat-recovery and non-recovery coke ovens in flat-type construction are widely described in prior art disclosures. For example, reference is taken to U.S. Pat. No. 4,344,820, U.S. Pat. No. 4,287,024, U.S. Pat. No. 5,114,542, GB 1 555 400 or CA 2 052 177 C.
According to the conventional state of the art in technology, primary air is sucked in from the atmosphere through ports in the doors. Secondary air is sucked in through ports near to ground and conducted through channels into the heating flues which mainly extend horizontally under the coke oven chamber. The ports for primary and secondary air are either opened permanently or provided with flaps designed to adjust the amount of air to be aspirated.
As the coke oven batteries are very extensive, and since usually a very high temperature prevails therein and because a serious development of dust is encountered, only manually adjustable ventilation flaps are disclosed in prior art technology. U.S. Pat. No. 5,928,476 describes such a coke oven battery, wherein three manually operable ports are provided in each coke oven door, in which or in front of which one plate or disk each adapted to the port cross-section and supported at a central axle is arranged. These port flaps can be varied in their position manually through levers.
In practice, however, it becomes evident that the required variation in the amount of primary and secondary air throughout the carbonisation time is effected with a manual adjustment only in very isolated cases and that the ideal time-dependent adjustment is thus by far not achieved. Furthermore, manual operation implies a serious burden to operators' health.
Now, therefore, it is the objective of this invention to remedy the described deficiencies in an economic manner and to assure an optimised supply of primary air and/or secondary air. Operational safety must be assured even with usually high temperatures and heavy impurities.
This invention solves this task by providing a device for supplying combustion air for the combustion of coking gas in cokemaking chambers of coke ovens built in flat-type construction and arranged as a battery of coke ovens, wherein the venting device consists of at least one vent port for each cokemaking chamber, said vent port extending through the relevant coke oven door or through its wall surrounding it, and wherein a freely-supported locking element is provided for each vent port, wherein
The connection between the locking element and the adjusting element as used hereunder shall be understood to mean that both elements may be connected to each other in a detachable way through a coupling element, for example a lever, rope tackle, chain, lever arm, etc. as well as combinations of these elements.
Advantageous embodiments provide for configuring the adjusting element as a rotating chain or as a steel cable. Using a screw spindle as adjusting element is another suitable embodiment. All these adjusting elements permit a permanent actuation into one moving direction which is very advantageous for the continuous overall process.
Furthermore, the device embodying this invention can be configured in such a manner that locking plates are installed as locking elements, said locking plates being supported in such a way that when actuated by the coupling element they are moved mainly in parallel to the oven door.
For a directed flow of primary gas it is of advantage for the vent port to be of a rotary-symmetrical shape. Therefore, the use of locking elements configured as upright standing locking plates and supported in vertically or horizontally rotatable arrangement around a central axle is advantageous.
With a further improved embodiment of said ventilation device, the locking elements are formed by at least two overlapping and reciprocally slideable facettes, with both facettes ideally exposing a polygonal and point-symmetrical or nearly circular cross-section when partly opened. Hence, there is no diversion of aspirated air in the vent port and because of the higher flow velocity the aspirated air is directed more deeply into the oven space.
A still advanced improvement resides in configuring the locking elements in conical shape, with the tip pointing towards the oven interior when built-in. This embodiment can still be further optimised in such a way that the vent port has the same or a wider angle of aperture than the pertaining conical locking elements. In this embodiment of the locking element for the device embodying this invention, the aspirated air is whirled-up minimally in the area of the locking element as well as in the area of the vent port and shaped to a gas jet independently of the size of the exposed cross-section.
With a different size of the conical angles of the vent port and locking element it can be assured that impurities accumulating in the vent port do not prevent a complete closure of the vent port. The conical locking element is moved via a lever structure and/or a spindle in the longitudinal direction of the vent port so that a circular ring gap is exposed when partly opened.
The ventilation device can be further improved by connecting the locking element with the adjusting element in such a way that it is automatically released from the adjusting element when being in the end position and when the vent port has been completely closed.
This invention furthermore comprises a device for supplying combustion air in coke ovens, in which the ventilation device embodying this invention as described before is implemented by one of its embodiment variants, with the sequence of the method being as set forth below:
An improved variant of this method is that the locking element being in the end position is automatically released from the adjusting element.
In another improved embodiment of the process embodying this invention, at least two central adjusting elements are provided for, wherein one adjusting element thereof actuates the locking elements for primary air and wherein the other central adjusting element actuates the locking elements for secondary air. Throughout the entire carbonisation time, the two adjusting elements are controllable completely independently of each other.
It is advantageous to actuate one central adjusting element continuously and mainly at the same speed or actuation frequency.
This invention also encompasses the use of the ventilation device embodying this invention in one of the embodiment variants outlined hereinabove with a method for supplying combustion air in cokemaking chambers of coke ovens built in flat-type construction and arranged as a battery of coke ovens.
This invention is described by way of three exemplary embodiment variants illustrated in
Moreover,
By a continuous movement of chain 11, the locking elements 6 are moved in counter-clockwise direction around the angle a while the locking elements 7 are moved in clockwise direction around angle β. The chains are driven via the central adjusting elements 13 and 14, respectively.
The supply of air to the coke oven 1 shown on the left side has already been closed completely and the lever arm 10 and the chain 15, respectively, have been released from the rotating chain 11. The locking elements 7 for the control of secondary air of the coke oven 1 shown on the left side are at a stage shortly before closure, but they are not yet closed completely. Hence, it is well conceivable that each coke oven 1 can be controlled absolutely individually despite a common central control.
A special embodiment variant of the locking elements 6 and 7 is illustrated in
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2005 055 483.0 | Nov 2005 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2006/009799 | 10/11/2006 | WO | 00 | 5/8/2009 |
