Sample collector for an oxyfuel process

Abstract

The present invention relates to a sample collector 10 for heat treatment of mineral material, wherein the sample collector 10 has a cylindrical tube 30, wherein the tube 30 is designed to pass through a wall of a heat treatment device, wherein a sample container 40 is arranged in the cylindrical tube 30 and is movable in the longitudinal direction of the tube 30, wherein the sample container 40 has, at least on the side facing the outside, a circular cross section 42 perpendicular to the axis of the tube 30 and closes the tube 30, wherein the sample container 40 is connected to a rod element 50 arranged in the longitudinal direction of the tube 30, wherein the rod element 50 is designed to move the sample container 40, wherein the tube 30 has, in the outer region, a connector piece 60 arranged on the underside, wherein the connector piece 60 can receive a laboratory sample container 70 or can be connected thereto, wherein the sample container 40, in a first rotation position and arranged above the connector piece 60, is designed to close the connector piece 60, and wherein the sample container 40, in a second rotation position, which is rotated 180° about the longitudinal axis of the tube 30 with respect to the first rotation position, and arranged above the connector piece 60, is designed to empty into the connector piece 60.

Description

[0001] Sampler for an oxyfuel process

[0002] The invention relates to a sampler for taking a powdered sample from an oxyfuel process.

[0003] The oxyfuel process is particularly suitable for avoiding carbon dioxide emissions, particularly in the thermal treatment of mineral materials and especially in the production of clinker from limestone. Clinker production in particular releases very large quantities of carbon dioxide, not only from the combustion of the fuel, but also from the limestone itself. Therefore, carbon dioxide separation is particularly important in this process. To simplify carbon dioxide separation, the oxyfuel process is increasingly being used. Ideally, pure oxygen is used as the combustion gas, so that in the end, practically only carbon dioxide (and water) remains in the gas phase. This eliminates the need for complex separation of carbon dioxide from the exhaust stream, as is the case with amine scrubbing, for example.

[0004] From DE 10 2018 206 673 A1, an oxyfuel clinker production with special oxygen gasification is known.

[0005] From DE 10 2018 206 674 A1, oxyfuel clinker production without recirculation of the preheater exhaust gases is known.

[0006] US 4 024 765 A discloses an automatic volumetric sampler for granular or powdery samples.

[0007] A device for taking samples is known from DE 10 2016 204 163 A1.

[0008] DE 10 2010 010 789 A1 discloses a sampler and a method for taking powder or granulate samples from a conveyor line.

[0009] US Pat. No. 4,630,479 A discloses a sampler for solids from a pressure reactor. However, this requires preventing the ingress of external air, and especially nitrogen, into the system, which requires sealing all potential openings to the outside of the system. For example, DE 10 2022 209 740 discloses a furnace seal for sealing the rotary kiln, particularly against the ingress of external gases.

[0010] Sampling has emerged as another potential source of air ingress. To monitor and control the process, samples are taken regularly and analyzed in the laboratory. The ingress of air must be avoided during sampling. One of the major challenges in sampling is the temperature at which the thermal treatment of mineral material takes place. Samples and the gas environment often have a temperature of around 1000 °C (± 200 °C). This complicates the design of suitable elements, especially since a sampler connects the high-temperature interior with the ambient-temperature exterior.

[0011] The object of the invention is to provide a sampler protected against the ingress of secondary air.

[0012] This object is achieved by the sampler having the features specified in claim 1 and by the method having the features specified in claim 9. Advantageous further developments emerge from the subclaims, the following description, and the drawings.

[0013] The sampler according to the invention is used for taking samples during the thermal treatment of mineral material, for example and in particular in the cement industry. In order to be able to regulate the process via the product properties, samples of the thermally treated mineral material must be taken from the hot area, for example at 800 to 1200 °C, during ongoing operation. The sampler is therefore used to take a sample from the material flow within the thermal treatment device, for example between the calciner and the rotary kiln. The sampler has a cylindrical tube. The tube is designed to be passed through a wall of a thermal treatment device. This means that a sample can be taken from the inside and brought to the outside through the tube. The tube thus serves to pass through the casing of the thermal treatment device.A sample container that can be moved in the longitudinal direction of the tube is arranged in the cylindrical tube. The sample container can, for example, be scoop-shaped. On the underside, the sample container is preferably adapted to the shape of the cylindrical tube so that it can be moved snugly. The sample container has a circular cross-section perpendicular to the axis of the tube, at least on the side facing the outside. The sample container thus closes the tube on the side facing the outside. The sample container is connected to a rod element arranged in the longitudinal direction of the tube; the rod element is designed to move the sample container. With the help of the rod element, the sample container and thus a sample can be removed from the interior of the thermal treatment device, or the empty sample container can be reinserted.The pipe in the outer area, i.e. outside the thermal treatment device, has a nozzle arranged on the underside. The nozzle is used for taking the sample. The nozzle can accommodate a laboratory sample container or can be connected to it. For example, the laboratory sample container can be placed in a gas-tight nozzle or the laboratory sample container can be connected to the nozzle via a screw thread, so that in this case the laboratory sample container closes off the nozzle at the bottom. The sample container is designed to close the nozzle in a first rotational position when arranged above the nozzle. This is preferably the removal rotational position of the sample container, thus the underside of the sample container, which preferably conforms to the shape of the pipe, preferably closes the nozzle. The sample container also has a second rotational position.The second rotational position, which is rotated by at least 90°, preferably 180°, around the longitudinal axis of the tube relative to the first rotational position, is designed, when positioned above the nozzle, for emptying into the nozzle. Thus, in the second rotational position (or better, already when rotating into the second rotational position), the sample falls from the sample container into the nozzle and thus ultimately into the laboratory sample container. The tube with the nozzle and attached or inserted laboratory sample container forms a closed space, whereby at no time is there a direct connection between the interior of the thermal treatment device and the ambient air, so that no gas can escape from the interior and no ambient air can enter.A minimal exchange, for example by changing the laboratory sample container within the sampler and thus indirectly between the ambient air and the interior of the thermal treatment device, is small enough to be neglected.

[0014] Thus, the sampler according to the invention, which can itself form a gas-tight space, can reliably prevent direct contact between the gas space inside the thermal treatment device and the ambient air and at the same time enables efficient sampling.

[0015] According to the invention, the nozzle has a closure device. The closure device can be used to close the nozzle, allowing the laboratory sample container to be changed without opening the sampler to the ambient air. The closure device can be designed, for example, in the form of a retractable plate.

[0016] According to the invention, the sampler comprises a sample container securing device. The sample container securing device serves to lock or release the laboratory sample container. For this purpose, the sample container securing device has a locked state in which the laboratory sample container cannot be removed. Furthermore, the sample container securing device has an unlocked state in which the laboratory sample container can be removed. The closure device is coupled to the sample container securing device in such a way that the sample container securing device can only be transferred to the unlocked state when the closure device is closed, and that the closure device can only be opened when the sample container securing device is in the locked state.This ensures that the closure device is never open and the laboratory sample container is never removed, preventing ambient air from entering the sampler. At the same time, the sample is already contained within the sampler in a laboratory sample container. This makes the sample much easier to transport. Furthermore, cleaning efforts can be minimized, as the sample is directly transferred into the laboratory sample container. The system according to the invention thus differs from conventional systems in its simple and low-contamination handling.

[0017] In a further embodiment of the invention, a sealing element is arranged on the rod element, closing the tube. This allows for additional sealing. Furthermore, the sealing element can be made of a flexible material, such as a heat-resistant plastic, thus providing a better seal. The distance from the sample container creates a separation from the very hot interior of the thermal treatment device, which expands the range of materials that can be used to manufacture the sealing element.

[0018] In a further embodiment of the invention, the nozzle has a closure device for closing the nozzle. This allows the gas space inside the sampler to be separated, allowing the laboratory sample container to be removed or replaced. This can reduce the penetration of ambient air into the interior of the sampler when changing the laboratory sample container and thus ultimately into the interior of the thermal treatment device.

[0019] In a further embodiment of the invention, the tube has a protective gas supply. A protective gas, for example an exhaust gas from the thermal treatment device or another, preferably carbon dioxide-rich gas, can be supplied via the protective gas supply, particularly when the sample container is moved, especially when the sample container is moved into the interior of the thermal treatment device. The volume of the gas space inside the sampler increases particularly when the sample container is moved into the interior of the thermal treatment device. To prevent the unwanted ingress of secondary air, the targeted supply of sealing gas is therefore advisable. Furthermore, gas can also be supplied via the protective gas supply, particularly when changing the laboratory sample container, in order to create a continuous gas flow to the outside and prevent the ingress of nitrogen from outside when the laboratory sample container is changed.

[0020] In a further embodiment of the invention, the sample container has a scoop shape. The sample container is guided into the product stream with the opening facing upwards, collects the sample, is then retracted over the nozzle and inverted there, so that the sample falls through the nozzle into the laboratory sample container.

[0021] In a further embodiment of the invention, the rod element is connected to an adjustment drive or is designed to be telescopic. While the adjustment drive is preferably located outside the internal gas chamber of the sampler, meaning the rod element must have a wall duct, a telescopic rod element can be arranged inside the gas chamber. Since hot gases are used, it may be advantageous for the telescopic rod element to be pneumatically operated.

[0022] In a further embodiment of the invention, the sampler comprises a

[0023] Control system for automated sample taking.

[0024] In a further embodiment of the invention, the sampler comprises a

[0025] A pressure relief valve is used. In particular, when the sample container is moved from inside the thermal treatment device toward the nozzle, the gas volume is reduced, compressing the gas inside the sampler, causing the pressure to rise. Therefore, a pressure relief valve is useful. Although this releases the carbon dioxide-rich gas into the environment, the amounts released are comparatively small compared to the overall process.

[0026] In a further embodiment of the invention, the tube of the sampler is inclined such that the end of the tube arranged inside the thermal treatment device is positioned lower than the end of the tube arranged outside the thermal treatment device. Accordingly, the nozzle, which is preferably arranged vertically or at least ± 10° to the vertical, is arranged at an angle to the tube. The tube preferably has an angle of at least 30°, more preferably of at least 40°, to the horizontal. Due to this inclination, particles remaining in the tube are conveyed by gravity from the interior of the tube back into the material flow of the thermal treatment device, thus preventing jamming of the sample container.

[0027] In a further aspect, the invention relates to a thermal treatment device with a sampler according to the invention.

[0028] Preferably, the thermal treatment device comprises a calciner and a furnace, and the sampler is arranged in the material flow between the calciner and the furnace.

[0029] In a further aspect, the invention relates to a method for taking a sample from a thermal treatment device. The method comprises the following steps: a) placing a sample container into a material stream in a thermal treatment device and thereby receiving a sample into the sample container, b) moving the sample container through a pipe via a nozzle using a rod element, c) rotating the sample container to empty the sample into the nozzle and through the nozzle into a laboratory sample container arranged below or in the nozzle, d) rotating the sample container back, e) moving the sample container through the pipe into the material stream using a rod element.

[0030] The laboratory sample container is secured with a sample container securing device. This means that the laboratory sample container cannot be easily removed, which in turn minimizes the risk that removal could create an unintentional connection between the outside environment and the interior, which could, for example, allow nitrogen from the environment to enter the interior in an unintentional and uncontrolled manner. A locking device for the nozzle and the sample container securing device are coupled in such a way that the sample container securing device can only be unlocked when the locking device is closed, and the locking device can only be opened when the sample container securing device is locked.This safety device ensures that the laboratory sample container can only be removed if it is ensured that there is no open connection to the interior and therefore no direct and uncontrolled penetration of nitrogen can occur.

[0031] Step e) transitions into step a) so that samples can be easily taken, for example, at specified time intervals.

[0032] The advantage of sampling is that the process allows the atmosphere inside the thermal treatment device to be separated from the environment, thus preventing the penetration of nitrogen in particular.

[0033] In particular, the transfer in step b) occurs in an ascending direction, i.e., against gravity. This has the advantage that particle buildup is less likely and thus jamming of the sample container can be avoided, as particles are transported from the tube back into the material flow by gravity.

[0034] In a further embodiment of the invention, protective gas is supplied via a protective gas supply while the sample container is moved within the tube. The protective gas can preferably be the exhaust gas from the thermal treatment plant itself or a similar carbon dioxide-rich gas. The purpose is to prevent the penetration of nitrogen, in particular from the ambient air.

[0035] In a further embodiment of the invention, the nozzle is closed by a closure device when changing the laboratory sample container. This minimizes the ingress of ambient air when changing the laboratory sample container. In a further embodiment of the invention, protective gas is supplied via the protective gas supply when changing the laboratory sample container. The continuous gas flow also ensures that no (or only as little as possible) nitrogen from the environment can enter the interior of the sample container and thus ultimately enter the interior of the thermal treatment device when opening the sample container.

[0036] In a further embodiment of the invention, waiting periods are inserted during step e) to adjust the time between sampling, in particular to adjust the transition from step e) to step a). Between the waiting periods between two samplings, the sample container is moved within the pipe at shorter intervals. This frequent movement avoids long downtimes, which in turn minimizes the risk of the sample container jamming in the dusty and very hot environment.

[0037] In a further embodiment of the invention, the laboratory sample container is then transported by pneumatic tube for analysis.

[0038] The sampler according to the invention is explained in more detail below using exemplary embodiments shown in the drawings.

[0039] Fig. 1 first embodiment, first position

[0040] Fig. 2 first embodiment, second position

[0041] Fig. 3 first embodiment, third position

[0042] Fig. 4 second embodiment, first position

[0043] Fig. 5 second embodiment, second position

[0044] Fig. 6 second embodiment, third position

[0045] Fig. 1 to Fig. 3 show a first embodiment, Fig. 4 to Fig. 6 a second embodiment.

[0046] The first embodiment shown in Fig. 1 to Fig. 3 will first be explained together and then only the different positions will be discussed below. The sampler 10 passes through a wall of a thermal treatment device 20, which, since it is not part of the sampler 10, is shown here in dashed lines. On the left side is the interior, where the material is thermally treated and where, in the oxyfuel process, a nitrogen-poor to nitrogen-free atmosphere prevails at 800 to 1200 °C. On the right side is the environment in which the sample is taken and used for further analysis.

[0047] A sample container 40 is arranged within the tube 30 and can be displaced in the longitudinal direction of the tube 30 using a rod element 50. For this purpose, the sampler 10 has an adjustment drive 52. A nozzle 60 is arranged below the tube 30, to which, in the example shown, a laboratory sample container 70 is arranged. In order to be able to regulate the gas inside the sampler 10, the sampler 10 has a protective gas supply 81 and a pressure relief valve 82. The tightness in the tube 30 is achieved, on the one hand, by the circular cross-section 42 of the sample container 40 and a sealing element 44 slightly spaced therefrom.

[0048] The method can be illustrated using the positions shown in Fig. 1 to Fig. 3. In Fig. 1, the sample container 40 is located inside and can thus receive a sample from the material stream. Between the first position in Fig. 1 and the second position in Fig. 2, the sample container 40 is retracted by means of the adjustment drive 52 and the rod element 50 until the sample container 40 has reached the second position above the nozzle. Since the volume within the sampler 10 is reduced in this process, gas escapes via the pressure relief valve 82. From the second position, the sample container 40 is rotated into the third position, as shown in Fig. 3. The sample falls from the sample container 40 through the nozzle 60 into the laboratory sample container.

[0049] The process is then reversed, and the sample container 40 is initially rotated back into the second position, as shown in Fig. 2. The sample container 40 is then moved back inside by the adjustment drive 52 and the rod element 50. Since the volume within the sampler 10 increases during this process, cold exhaust gas from the gas treatment device, for example, is supplied via the protective gas supply 81. The second embodiment shown in Fig. 4 to Fig. 6 differs from the first embodiment shown in Fig. 1 to Fig. 3 by an inclined position of the tube 30. Furthermore, the first embodiment and the second embodiment are the same, so that the statements regarding the first embodiment apply analogously to the second embodiment.

[0050] Reference symbol

[0051] 10 samplers

[0052] 20 Wall of the thermal treatment device

[0053] 30 pipe

[0054] 40 sample containers

[0055] 42 circular cross-section

[0056] 44 Sealing element

[0057] 50 rod element

[0058] 52 Adjustment drive

[0059] 60 nozzles

[0060] 70 laboratory sample containers

[0061] 81 Shielding gas supply

[0062] 82 pressure relief valve

Claims

Patent claims 1. A sampler (10) for the thermal treatment of mineral material, wherein the sampler (10) comprises a cylindrical tube (30), wherein the tube (30) is designed to pass through a wall of a thermal treatment device, wherein a sample container (40) movable in the longitudinal direction of the tube (30) is arranged in the cylindrical tube (30), wherein the sample container (40) has a circular cross-section (42) perpendicular to the axis of the tube (30) at least on the side facing the outside and closes the tube (30), wherein the sample container (40) is connected to a rod element (50) arranged in the longitudinal direction of the tube (30), wherein the rod element (50) is designed to move the sample container (40), wherein the tube (30) has a nozzle (60) arranged on the underside in the outer region, wherein the nozzle (60) can accommodate a laboratory sample container (70) or be connected to it,wherein the sample container (40) is designed in a first rotational position when arranged above the nozzle (60) to close the nozzle (60), wherein the sample container (40) is designed in a second rotational position, which is rotated by at least 90°, preferably by 180°, about the longitudinal axis of the tube (30) relative to the first rotational position, when arranged above the nozzle (60) to empty into the nozzle (60), characterized in that the nozzle (60) has a closure device, wherein the sampler (10) has a sample container securing device, wherein the sample container securing device has a locked state in which the laboratory sample container (70) cannot be removed, wherein the sample container securing device has an unlocked state in which the laboratory sample container (70) can be removed, wherein the closure device is coupled to the sample container securing device in such a way,that the sample container securing device can only be transferred to the unlocked state when the locking device is closed and that the locking device can only be opened when the sample container securing device is in the locked state.

2. Sampler (10) according to claim 1, characterized in that a sealing element (44) closing the tube (30) is arranged on the rod element (50).

3. Sampler (10) according to one of the preceding claims, characterized in that the nozzle (60) has a closure device for closing the nozzle (60).

4. Sampler (10) according to one of the preceding claims, characterized in that the tube (30) has a protective gas supply (81).

5. Sampler (10) according to one of the preceding claims, characterized in that the sample container (40) has a scoop shape.

6. Sampler (10) according to one of the preceding claims, characterized in that the rod element (50) is connected to an adjustment drive (52) or is designed to be telescopic.

7. Sampler (10) according to one of the preceding claims, characterized in that the sampler (10) has a control system for automated sampling.

8. Sampler (10) according to one of the preceding claims, characterized in that the sampler (10) has a pressure relief valve (82).

9. A method for taking a sample from a thermal treatment device, the method comprising the following steps: a) placing a sample container (40) into a material flow in a thermal treatment device and thereby receiving a sample in the sample container (40), b) moving the sample container (40) through a pipe (30) via a nozzle (60) by means of a rod element (50), c) rotating the sample container (40) to empty the sample into the nozzle (60) and through the nozzle (60) into a laboratory sample container (70) arranged below or in the nozzle (60), d) turning back the sample container (40), e) moving the sample container (40) through the tube (30) into the material flow by means of a rod element (50), wherein the laboratory sample container (70) is provided with a Sample container securing device is secured, wherein a closure device of the nozzle and the sample container securing device are coupled to one another in such a way that the sample container securing device can only be transferred into the unlocked state when the closure device is closed and that the closure device can only be opened when the sample container securing device is in the locked state.

10. The method according to claim 9, characterized in that while the sample container (40) is moved in the tube (30), protective gas is supplied via a protective gas supply (81).

11. Method according to one of claims 9 to 10, characterized in that the nozzle (60) is closed by means of a closure device when changing the laboratory sample container (70).

12. Method according to one of claims 9 to 11, characterized in that during step e) waiting breaks are inserted in order to adjust the time between the samplings, wherein between the waiting breaks between two samplings the sample container (40) is moved in the tube (30).

13. Method according to one of claims 9 to 12, characterized in that the laboratory sample container (70) is subsequently transported by pneumatic tube for analysis.

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