Patent Application
20240210032
The present disclosure relates to a camera module for use with a burner, a burner for a shaft melting furnace, in particular for a copper shaft melting furnace, along with a method for operating the burner.
Whether in electrical engineering and electronics, in heating and air-conditioning technology or in the automotive industry—it is impossible to imagine modern life without the use of copper and copper alloys, as a result of which global demand for this precious metal is constantly increasing. However, global demand is offset by increased safety and environmental requirements for production. Among other things, powerful burners with automatic monitoring of the flame chamber are indispensable for this purpose.
Burners for a shaft melting furnace are generally known from the prior art. For example, WO 90/02909 discloses a generic burner with a conically shaped first chamber, an adjoining mixing chamber along with a telescopic eyepiece that extends axially through the burner. The burner known from WO 90/02909 exhibits substantially complete combustion and a uniform flame composition, but on the one hand does not satisfy today's increased environmental requirements and on the other hand does not enable permanent, in particular automatic, flame monitoring.
From the Chinese publication CN106545858 A, a burner with a cylindrical first chamber is also known, which burner comprises a camera arranged behind a glass pane at its end arranged opposite the combustion chamber. Thereby, the camera is connected to a monitor via which an operator can observe the process from a distance.
The present disclosure provides a burner that is improved compared to the prior art, in particular a burner with which an outlet region of the burner along with the flame chamber of the shaft melting furnace can be monitored automatically and manually. Furthermore, the present disclosure to provides an improved method for operating such a burner compared to the prior art.
A camera module is intended for use with a burner typically used in a shaft melting furnace, in particular a copper shaft melting furnace, in order to melt down a melting material such as copper cathodes, etc. For this purpose, the camera module is arranged on the burner or an observation device of the burner and comprises a housing having a first opening and a second opening, which is arranged axially opposite the first opening and is closed off by an inspection glass; a beam splitter arranged on an optical viewing axis extending axially through the housing between the two openings; and a camera, for example a CCD camera, the lens of which is arranged perpendicularly to the optical viewing axis and is aligned with the beam splitter. For this purpose, the beam splitter advantageously comprises a semi-transparent splitter mirror arranged at an angle of 45°, which can be mounted in a fixed position on a holder element, for example. Alternatively, a 45° beam splitter prism can be used.
By means of the camera module, the outlet region of the burner along with the flame chamber of the shaft melting furnace can be automatically monitored and continuously evaluated by means of a connection to a computer-aided unit, wherein the results can subsequently be fed to a burner control loop. Thus, process disruptions can be identified more quickly and production downtimes can be effectively reduced by avoiding major accidents. On the other hand, the structure of the camera module simultaneously permits manual monitoring, which can be performed by an operator alternatively or additionally, for example in order to verify a process disruption identified via the camera of the camera module.
A burner for a shaft melting furnace, in particular for a copper shaft melting furnace, will now be described in more detail. In accordance with a first embodiment, the burner comprises an observation device having an optical viewing axis extending through a first chamber, a burner nozzle and a radiant tube of the burner, via which a flame chamber of the shaft melting furnace can be monitored; along with a camera module arranged on the observation device. In accordance with a second embodiment, the burner comprises an observation device with an optical viewing axis extending through a first chamber, a second chamber, a burner nozzle and a radiant tube of the burner, via which a flame chamber of the shaft melting furnace can be monitored; along with a camera module arranged on the observation device.
Further advantageous embodiments of the invention are indicated in the dependent formulated claims. The features listed individually in the dependent formulated claims can be combined with one another in a technologically useful manner and may define further embodiments of the invention. In addition, the features indicated in the claims are further specified and explained in the description, wherein further preferred embodiments of the invention are shown.
In an advantageous embodiment, the observation device comprises a tube extending axially through the first chamber, wherein a first end of the tube is arranged outside the burner and is connected to the camera module, preferably via an adapter device of the camera module. A second end of the tube is arranged in a central opening of a mixing nozzle, which is positioned in an outlet opening of the first chamber, and is locked, for example, by means of a bayonet lock. Thereby, the outlet opening is preferably arranged at a distal end of a conically tapering partial section of the first chamber.
Further, the first chamber comprises an inlet opening through which an oxygen-containing gas, such as air, oxygen-enriched air, or pure oxygen, can be fed to the burner, and a fuel gas line opening into the first chamber through which a fuel gas can be fed to the burner.
From the point of view of fluid dynamics, it has been shown that a fuel gas line arranged coaxially around the tube of the observation device is particularly advantageous. Therefore, it is preferably provided in this connection that the fuel gas line is arranged coaxially around the tube of the observation device and comprises at its end oriented towards the mixing nozzle a plurality of nozzle openings, which are particularly preferably arranged in a manner distributed over the circumference thereof. Each of the plurality of nozzle openings is oriented at an angle of 40° to 50°, preferably at an angle of 45°, with respect to the visual or longitudinal axis, as the case may be, of the burner, in order to achieve a particularly high premixing between the fuel gas flowing out of the nozzle openings and the oxygen-containing gas.
By arranging the fuel gas line in the conical partial section of the first chamber, which serves as a collection chamber for the oxygen-containing gas, the fuel gas is premixed with the oxygen-containing gas. The premixed fuel gas mixture then flows through the mixing nozzle arranged in the outlet opening and is then homogeneously mixed in the mixing chamber, which advantageously has a specific mixing geometry. Thereby, the entire mixing nozzle is designed in such a manner that it causes a particularly low pressure loss of only 70 mbar. This ultimately ensures that the permanent pressure loss at the burner can be continuously kept to a minimum, as a result of which the burner has a better energy balance compared with burners known from the prior art.
Suitable fuel gases include hydrocarbon gases, in particular methane or natural gas, hydrogen or mixtures thereof. The mixture, for example one of natural gas or methane and hydrogen, is advantageously premixed individually in the range from 1 to 100% by volume, for example in a valve station, and then fed to the burner via the fuel gas line. One advantage of blending hydrogen with the hydrocarbon-containing gas is that it allows a flexible response to rising CO2 prices in the future. Thereby, it is particularly preferred that the hydrogen has been obtained by means of renewable energies.
As already explained, the mixing nozzle causes a particularly low pressure loss, which has an energetically advantageous effect on the operation of the burner. The low pressure loss is achieved by the specific mixing geometry, which is advantageously formed by a plurality of blades arranged in the annular mixing chamber. The annular mixing chamber has an outer ring with preferably a first set of radially outwardly arranged blades and an inner ring with preferably a second set of blades arranged radially on the inside, wherein the two sets of blades are counterrotatingly arranged relative to one another. The blades of the first and second sets are arranged relative to one another in such a manner that each blade of the first set forms three shear planes with three blades of the second set, and each blade of the second set forms three shear planes with three blades of the first set, as the case may be. This arrangement ensures that the fuel gas mixture flowing over the blade surfaces of the radially outwardly arranged blades strikes the blade surfaces of the radially inner blades, which are arranged substantially perpendicularly thereto, and thereby mixes with the fuel gas mixture flowing over the blade surfaces of the radially inner blades and vice versa. This multiple intermixing of the already premixed fuel gas mixture achieves homogeneous mixing of the two gases while keeping permanent pressure loss low.
The burner nozzle, which advantageously comprises a plurality of guide blades, is arranged at the end of the second chamber axially opposite the mixing nozzle. These are arranged in a front region of the burner nozzle in the direction of flow. The guide blades are designed and aligned relative to one another in such a manner that the fuel gas mixture is driven to the center of the channel, which generates turbulence in the center region on a targeted basis and thus prevents free flow of the fuel gas mixture. This ensures that, while maintaining the optical viewing axis, a homogeneous speed profile is achieved over the entire cross-section of the radiant tube and that the fuel gas mixture can react completely before hitting the melting material to be melted down, such that there are no strands without a reaction.
In the rear region in the direction of flow, the burner nozzle then has a conically tapering outlet opening, the edge of which, in accordance with an advantageous embodiment, has a serrated structure, in particular one provided with recesses, via which turbulence can be generated in a targeted manner, which leads to the formation of a stable flame root. An ignition ionization candle is provided for igniting the burner, which is arranged just behind the edge and can advantageously be continuously monitored via an ionization monitor. For this purpose, it is necessary that the monitoring wire is always positioned in the flame throughout the entire output spectrum of the burner. Due to the formation of the stable flame root, this can be guaranteed at all times.
In a further aspect, the present disclosure also relates to a method for operating the burner, wherein a tube inner surface of the radiant tube is continuously monitored by means of the camera module by comparing the detected individual images with a reference image, and an automatic acoustic and/or visual warning message is output if an actual value exceeds a target value. In this connection, it is preferably provided that if the actual value exceeds the target value, an automatic control system is additionally activated, which throttles the burner output of the burner.
Using the method, clogging of the radiant tube with the melting material, in particular with copper particles, can be identified at an early stage and appropriate countermeasures can be initiated. If the automatic control system is activated, the burner output at the burner can be throttled, as a result of which the flame is shortened and an edge region of the lining of a shaft melting furnace, in particular a copper shaft melting furnace, is heated to a greater extent. This melts away the adhesions. As soon as the tube inner surface has reached a predetermined value again, preferably a value of more than 90 surface percent, the output is increased again. In order to increase the temperature of the flame, it can further be provided that composition of the fuel gas mixture is manipulated, for example by setting it to a lambda value of 1.
In a further advantageous embodiment of the method, the camera module can also be used to continuously monitor the level of melting material by comparing the detected individual images with a reference image, and outputting an automatic acoustic and/or visual warning message if an actual value exceeds a target value. Thereby, the camera module detects the level of a reflective surface of a so-called “melting material pool,” in particular a “copper pool,” since such a pool can lead to a blockage of the burner and thus to costly manual cleaning. If the level of melting material exceeds a critical value, the burner outputs of, for example, an upper burner row can be automatically reduced in order to reduce the amount of melting material flowing into the shaft melting furnace. The In a further advantageous embodiment, the brightness of the flame chamber of the shaft melting furnace in the region upstream of the respective burner is monitored by means of the camera module by comparing the detected individual images with a reference image and/or at least one individual image of another burner arranged in the shaft melting furnace, and outputting an automatic acoustic and/or visual warning message if an actual value exceeds and/or falls below a target value. If a difference in brightness is identified, a maintenance request can be sent to maintenance, for example. Alternatively, the composition of the fuel gas mixture can be adjusted and the identified brightness can be controlled on the basis of this.
The invention and the technical environment are explained in more detail below with reference to the figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments shown. In particular, unless explicitly shown otherwise, it is also possible to extract partial aspects of the facts explained in the figures and combine them with other components and findings from the present description and/or figures. In particular, it should be noted that the figures and in particular the size relationships shown are only schematic. Identical reference signs designate identical objects, such that explanations from other figures may be used as a supplement if necessary.
The burner 1 shown in the present embodiment comprises a first nozzle 2, via which an oxygen-containing gas, such as air, can be fed to the burner 1, and a second nozzle 3, via which a fuel gas can be fed to the burner 1. For example, the fuel gas can comprise a hydrocarbon-containing gas, such as natural gas or methane, hydrogen or a mixture thereof. Furthermore, the burner 1 comprises a first chamber 4 that has a conical partial section 5, a second chamber 6 having a burner nozzle 7 (see
In order to be able to install the burner 1 ergonomically, it has two crane lugs 41 on the outer side of the second chamber 6, which are located at the center of gravity and in each case comprise an elongated hole, in order to compensate for changes in the center of gravity that may result from supplementary attachments.
The burner 1 can be fed with the oxygen-containing gas both from above, as shown in
On the one hand, such representation shows the first chamber 4, which has an inlet opening 14 through which the oxygen-containing gas is introduced into the first chamber 4 via the first nozzle 2. The first chamber 4 comprises, in addition to a main section 15 into which the inlet opening 14 opens, the conically tapering partial section 5 which has an outlet opening 16 arranged at its distal end. Connected to the conical partial section 5 of the first chamber 4 is the second chamber 6, which is formed from a hollow cylindrical element, for example a tube, and has a first end 17 facing the conical partial section 5 along with an axially opposite second end 18, at which the burner nozzle 7 is arranged. In the present case, the burner nozzle 7 is made of steel by means of an additive manufacturing process and is explained in more detail in
A mixing nozzle 19 with a mixing chamber 20 is arranged at the first end 17 of the second chamber 6 or in the outlet opening 16 of the first chamber 4, as the case may be, via which the oxygen-containing gas and the fuel gas can be mixed to form a fuel gas mixture. Thereby, the fuel gas is introduced into the burner 1 via a fuel gas line 21, which opens out in the first chamber 4, in particular in the conically tapering partial section 5 of the first chamber 4.
As can be seen from the representation in
The tube 22 of the observation device 9, which extends axially through the first chamber 4, has a first end 24. The first end 24 of the tube 22 is arranged outside the burner 1 and is connected to the camera module 10, via the adapter device 107 (see
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2021 204 973.7 | May 2021 | DE | national |
This application is a national stage application, filed under 35 U.S.C. § 371, of International Patent Application PCT/EP2022/058355, filed on Mar. 30, 2022, which claims the benefit of German Patent Application DE 10 2021 204 973.7, filed on May 17, 2021.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/058355 | 3/30/2022 | WO |
