Patent Application
20100276269
The invention relates to a method of filling an oven chamber of a coke-oven battery, wherein by means of at least one measuring device arranged on a leveling rod, and by means of a processing unit connected to the measuring device, the profile of the bulk material within the oven chamber during the filling process is determined, and wherein depending on the determined profile of the bulk material an additional loading of the oven chamber takes place. Subject matter of the invention is in addition a leveling apparatus for carrying out the method.
In coking plants, the oven chambers of a coke-oven battery are filled through filling holes by a filling machine arranged moveable on the coke-oven battery. For this, the loading of the individual filling holes is typically carried out via allocated, speed-controlled screw-conveyors which fill the coking coal through coal funnels into the oven chamber. The design of the screw-conveyors and the setting for the developing of the rotational frequency of the screw during the filling cycle are particularly dependent on the volume of the oven chambers, the aimed filling time, the filling sequence of the different oven chambers of a coke-oven battery, and the size of the coal funnel of the filling machine. To evenly distribute the coking coal of the bulk material cone formed during filling, a leveling apparatus is provided comprising a leveling rod which is introduced in an upper region of the oven chamber through a leveling opening in an oven chamber door and is moved in the longitudinal direction of the oven chamber.
From practice is known to determine the filling levels underneath the filling holes during the start up of the filling machine, obtained with an initial setting for the developing of the screw frequency, and to estimate therefrom the filling degree, wherein on the basis of the estimation, an adjustment of the screw-frequency takes place to achieve an improved coal charge. The determined settings provide a basis for the continuous operation of the coke-oven battery and can be checked by means of repeated measurements of the filling level underneath the filling holes, or by determination of the coke cake profile at ejection.
A method of filling an oven chamber of a coke-oven battery comprising the above mentioned features is known from DE 10 2005 007 164 A1, wherein the measuring device comprising a contact sensor is arranged on the head of the leveling rod. The measuring device detects the contact-making and the contact-losing with a bulk material discharge cone formed by the filled coking coal. From the measurement signals, the bulk material filling progress is determined by the processing unit, wherein based on this information, an additional loading of the oven chamber can take place. Thereby the bulk material filling progress can only be determined, when the formed bulk material cones have reached the level of the leveling rod, and the oven chamber is already filled to a large extent. In addition, the accuracy of the described method needs to be improved because the exact shape of the bulk material cone can not be determined based on the signals of the contact sensor. Thus, the steepness of the individual bulk material cones can greatly depend on the size distribution and the surface structure of the coking coal used for coking and can not by implication be predetermined.
From the publication DE 10 2005 010 114 A1, which relates to a method and a system for controlling an operating unit of a coke oven, is known to determine the filling level during the filling cycle underneath the filling holes of an oven chamber. On the basis of the information determined in that way, the bulk material filling progress in longitudinal direction can only be estimated roughly because the exact filling level between the individual filling holes is not known. Furthermore, the profile of the coke cake surface can be determined at the ejection, wherein from the obtained data, the bulk material progress profile previously achieved during the filling of the oven chamber and the filling level can only be determined with some uncertainty because of the shrinkage behavior of the coking coal during the coking process. Furthermore, based on the downstream evaluation of the coke cake profile, only the adjustment of a subsequent filling is possible, wherein a consideration and a compensation of variations during the filling, which are not completely reproducible, is impossible.
Against this background, the invention is based on the problem to provide a method of filling an oven chamber of a coke-oven battery, by means of which a uniform bulk material discharging progress and an increase of the filling degree of the oven chamber can be achieved.
Based on a method comprising the above described features the problem is solved according to the invention in that by the at least one measuring device, in longitudinal direction and transverse direction of the oven chamber, a three-dimensional filling level profile is determined contactless. By means of the determination of the three-dimensional filling level, the uniformity of the bulk material filling progress, and the filling degree can exactly be determined directly during the filling. By the direct evaluation by means of the processing unit, the additionally added volume of coking coal can then be calculated continuously, wherein depending on the actually determined filling profile and volume, a control of the filling process according to the requirements is possible. For example, in a filling device, screw-conveyors can be provided which are allocated to one filling hole of the oven chamber, respectively, and the rotational frequencies of the screws in each case are controlled independently from each other. In doing so, an empty volume remaining for the maximum filling can only be determined without restriction for a region of the oven chamber which was just passed by the measuring device, or for the whole oven chamber. With a fast evaluation of the measurement signals, thus a direct, continuous adjustment of the control signals during the filling process is also possible.
By means of the contactless determination of the three-dimensional filling level profile, an accurate control is possible at an early stage during the filling cycle. In the embodiment known from DE 10 2005 007 164 A1, a filling underneath one of the filling holes which is too high or too low, is recognized only upon contact of the respective bulk material discharge cone with the leveling rod, wherein then, by an adjusted control of the frequencies of the screw-conveyors, or a repeated leveling with the leveling rod, a substantial delay of the filling cycle can occur. In contrast to that, according to the invention, the profile of the bulk material can be determined early with a very high accuracy, and a uniform filling can be ensured so that within a comparatively short filling time, an optimal filling can be realized. Since the measuring device operates contactless, the risk of wear by mechanical stress can also be minimized.
The contactless determination of the filling level profile with the measuring device can be carried out, for example, by means of laser beams, microwaves, and/or ultrasound by at least one measuring beam or a bundle of measuring beams. The measuring is unit can be arranged without restriction at a leveling section formed as, for example, a rake blade at the front end of the leveling rod, or at a support section of the leveling rod adjacent thereto. The position of the measuring unit can be determined in a particularly simple manner from the leveling rod's path signal which, for example, is provided by a control of the leveling rod, a central control unit, or a path sensor arranged on the leveling rod.
During the three-dimensional determination of the bulk material discharge progress by the processing unit, typically a determination of the filling level at discrete points, which in longitudinal direction and transverse direction of the oven chamber form a grid, takes place, wherein the intermediate values can be determined by interpolation. In doing so, the bulk material filling progress in transverse direction is preferably determined directly up to the border of the oven chamber to be able to determine the filling volume as accurate as possible, wherein advantageously across the width of the oven chamber in the transverse direction and the distance between two filling holes of the oven chamber in longitudinal direction, at least five grid points are provided, respectively. However, preferably, a finer spacial resolution is provided, wherein a resolution which is below the typical grid size of the filled coking coal is in fact possible with suitable measuring systems, but is typically not required. Optionally, the distance to the ceiling of the oven chamber can additionally be determined and can be considered for the control of the filling and/or as a monitor for the correct positioning of the is leveling rod.
While in the methods for filling an oven chamber of a coke-oven battery known from the prior art, the leveling rod always is moved in a predetermined manner, in a further development of the present invention can be provided that the leveling rod is positioned by the processing unit depending on the determined three-dimensional filling level profile in longitudinal direction of the oven chamber, whereby the filling time can further be reduced and the result of the filling can be improved.
Within the scope of a preferred embodiment is provided that on the leveling rod at least two measuring devices are arranged which are operating contactless and are spaced apart from each other in longitudinal direction of the leveling rod. With a plurality of measuring devices which are spaced apart, at different positions in the longitudinal direction of the oven chamber, filling level profiles can be determined in transverse direction at the same time so that during filling, an overall improved accuracy of the determination of the filling progress can be achieved, in particular because during the filling process, the filling level in the different areas of the oven chamber changes constantly. Moreover, even in case of a breakdown of a measuring device or a portion of the measuring units, via the measuring devices still remaining functional, a determination of the profile of the bulk material is possible, however with a reduced accuracy.
In spite of the temperatures prevailing inside the oven chamber, the aggressive gas components of the coke gas formed inside the oven chamber, and the particulate solids contained in the coke gas, within the scope of the method according to the invention, a reliable operation of the measuring device which functions contactless and which is introduced directly into the oven chamber together with the leveling rod is surprisingly possible. To further increase the reliability of the method according to the invention, a cleaning device for the at least one measuring device can be provided. Thus, the measuring device can be flushed during the filling process with a separately supplied flushing medium, for example air. In addition, or alternatively, between the filling cycles of the different oven chambers of a coke-oven battery, a chemical and/or mechanical cleaning of the at least one measuring device can also be provided. Finally it is also possible to arrange parts of the at least one measuring device on the leveling rod such that, during the filling cycle, they are still arranged outside of the oven chamber. Thus, the measuring device can comprise, for example, mirrors, fiber optics, hollow wave guides, or the like, wherein electronic components of the measuring device during the operation of the leveling apparatus are located outside of an oven chamber to be filled.
Subject matter of the invention is in addition a leveling apparatus according to claim 5 for carrying out the previously described method. The subsequent claims 6 to 9 relate to advantageous embodiments of the leveling apparatus.
The invention is explained hereinafter by means of a drawing illustrating an exemplary embodiment only. In the figures
In
As is to see in
While in the embodiments known from the prior art, the leveling rod 9 is moved in and out in a predetermined manner, the leveling rod 9, according to the invention, can be variably positioned in the longitudinal direction of the oven chamber 1 during the filling cycle, depending on the determined three-dimensional filling level profile.
The determination of the filling level profile by means of the at least one measuring device 11 can take place, for example, by means of laser beams, microwaves and/or ultrasound. By means of the contactless determination of the filling level, in addition, a mechanical wear of the measuring device 11 is avoided. To increase the reliability of the measuring device 11, the same can be cleaned or protected against pollution by means of a cleaning device. Moreover, in addition, sensitive parts of the measuring device 11 can be arranged such that they are located outside of the oven chamber during the leveling process while filling.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102007057348.2 | Nov 2007 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP08/09370 | 11/6/2008 | WO | 00 | 7/26/2010 |
