Reactor

Abstract

The invention relates to a reactor (1; 30; 40) comprising: a reactor container (4) in which a fluidized bed (6) or a moving bed or a fluid bed can be formed; and an electric heating device for heating the fluidized bed (6) or the moving bed or the fluid bed. A functional element (10; 20) of the electric heating device, to which functional element an electrical voltage is applied for heating the fluidized bed (6) or the moving bed or the fluid bed, is arranged outside the fluidized bed (6) or the moving bed or the fluid bed and is vibration-damped or vibration-decoupled with respect to vibrations excited by the fluidized bed (6) or the moving bed or the fluid bed.

Description

[0001] Description

[0002] reactor

[0003] The invention relates to a reactor, in particular a fluidized bed reactor or moving bed reactor, with a reactor vessel in which a fluidized bed or a moving bed or a fluidized bed can be formed, and an electric heating device for heating the fluidized bed or the moving bed or the fluidized bed.

[0004] Fluidized bed and moving bed reactors from the field of thermal process engineering are generally known from the prior art. These reactors can be used, for example, for pyrolysis, calcination of carbonates, thermochemical gasification of carbon-containing materials, sintering of limestone, sintering of cement clinker, or sintering of iron ore pellets. The endothermic reactions taking place within a fluidized bed or moving bed in these reactors occur at high temperatures over a long operating period and require a continuous and reliable energy input in the form of heat.

[0005] In the prior art, fluidized beds are heated, for example, by coupling the fluidized bed reactor with a combustion chamber, which is often also designed as a fluidized bed combustion chamber. Such dual fluidized bed reactors have become established in the field of biomass gasification as Dual Fluidized Bed gasifiers (DFBs) and in the field of CO2 capture from flue gases as carbonate looping processes. Furthermore, it is known to heat the fluidized bed inductively or to integrate electrodes into the fluidized bed and heat the conductive fluidized bed material by applying a voltage.

[0006] From publication WO 2011 / 026629 A2, a fluidized bed reactor for the production of pyrolysis gas and / or synthesis gas from essentially solid fuels, especially biomass, is known, which has an electric heating device for heating a fluidized bed formed within the reactor. The electric heating device can include an electrical resistance heating element in the form of a tube arranged within the fluidized bed, at the ends of which an electrical voltage is applied. The tube can be considered a energized functional element of the electric heating device. The tube also forms porous sections through which gas introduced into the tube, especially oxygen-containing gas, can be preheated. The introduced gas can contribute to further heat release through oxidation with a combustible gas, such as pyrolysis gas or synthesis gas.

[0007] The arrangement of the electrical resistance heating element within the fluidized bed, as shown in WO 2011 / 026629 A2, has the disadvantage that the unavoidable movements of the fluidized bed material are transmitted to the fluidized bed reactor, i.e., a fluidized bed reactor vessel and the resistance heating element arranged within the fluidized bed, and can cause oscillations or vibrations that can lead to mechanical failure of the resistance heating element after only a short operating period. A further problem arising from the resistance heating element being arranged within the fluidized bed is that slag formed from the carbon-containing feedstock and the bed material can be deposited on the resistance heating element due to its high surface temperatures.These slag deposits can negatively affect heat transfer from the resistance heating element to the fluidized bed, as well as damage the resistance heating element and lead to failure after only a short operating period. Finally, it is known that at very high temperatures, leakage currents can occur between the electrical resistance heating element and the fluidized bed reactor vessel, which can become unacceptably high and negatively affect measuring instruments or endanger operating personnel.

[0008] Starting from the fluidized bed reactor shown in WO 2011 / 026629 A2, the object of the present invention is to provide a reactor with a reactor vessel in which a fluidized bed or a moving bed or a fluidized bed can be formed, and an electric heating device for heating the fluidized bed or the moving bed or the fluidized bed, which can reduce or avoid the transmission of vibrations excited by the fluidized bed or the moving bed or the fluidized bed to a energized functional element of the electric heating device and prevent slag deposits on the functional element.

[0009] The problem is solved by a reactor having the features according to independent claim 1. The dependent claims relate to advantageous embodiments.

[0010] A reactor according to the invention comprises a reactor vessel in which a fluidized bed, a moving bed, or a fluidized bed can be formed, and an electric heating device for heating the fluidized bed, the moving bed, or the fluidized bed. A functional element of the electric heating device, which is subjected to an electrical voltage for heating the fluidized bed, the moving bed, or the fluidized bed, is arranged outside the fluidized bed, the moving bed, or the fluidized bed and is vibration-damped or vibration-decoupled from vibrations excited by the fluidized bed, the moving bed, or the fluidized bed.

[0011] The reactor according to the invention can be used, for example, for pyrolysis, calcination of carbonates, thermochemical gasification of carbon-containing materials, sintering of lime, sintering of cement clinker, or sintering of iron ore pellets. However, the reactor's field of application is not limited to these uses, as long as a fluidized bed, a moving bed, or a fluidized bed heated by an electric heating device is present within the reactor.

[0012] Depending on whether the reactor vessel contains a fluidized bed, a moving bed (also known as a fluidized bed), or a fluidized bed, the reactor according to the invention can therefore be a fluidized bed reactor, a moving bed reactor, or a fluidized bed reactor. As described later, the electrical heating device can be designed as a resistance heater or an inductive heater. The electrically charged functional element can be considered the element of the electrical heating device that is to be protected from unwanted vibrations and slag deposits or other unwanted deposits, such as deposits that could reduce the performance of the functional element or damage it, and that is not to react with any reactant / product in the reactor vessel.In the case of resistance heating, a resistance heating element itself, subjected to an electrical voltage, can constitute the functional element; in the case of inductive heating, an inductive heating element, for example an induction coil, subjected to an electrical voltage, can constitute the functional element. Within the scope of the invention, the term "vibrations" that are caused or excited by the fluidized bed, moving bed, or flow bed includes vibrations, shocks, impacts, impulses, and the like.

[0013] By positioning the electrically charged functional element outside the fluidized bed, moving bed, or flow bed, direct contact between the fluidized bed, flow bed, or moving bed material and the functional element can be prevented. Consequently, the high surface temperatures of the functional element prevent the deposition of slag materials, which can form from the carbon-containing feedstock and the bed material. Furthermore, the functional element is vibration-damped or vibration-decoupled from vibrations excited by the fluidized bed, moving bed, or flow bed, thus preventing mechanical failure of the functional element and, consequently, of the electrical heating device.The functional element is also advantageously arranged in a vibration-damped or vibration-decoupled manner with respect to vibrations originating from elements other than the fluidized bed or the moving bed or FN0709P-WG-0007.

[0014] 5 / 19 the fluidized bed is stimulated, e.g. by a conveying system adjacent to the reactor or auxiliary units of a fluidization system.

[0015] The functional element can be designed as a resistance heating element and be shielded from the fluidized bed or the moving bed or the fluidized bed by means of a shielding element that penetrates into or through the fluidized bed or the moving bed or the fluidized bed.

[0016] Resistance heating elements offer a very simple and cost-effective way to convert electrical energy into thermal energy by applying an electrical voltage to an electrically conductive material, thereby heating the fluidized bed, moving bed, or fluidized bed. The shielding element ensures effective physical separation of the fluidized bed, moving bed, or fluidized bed from the functional element, thus ensuring that the functional element is located outside the fluidized bed, moving bed, or fluidized bed. Preferably, the shielding element penetrates the fluidized bed, moving bed, or fluidized bed, thereby achieving a uniform heat input from the resistance heating element, via the shielding element, into the fluidized bed, moving bed, or fluidized bed.

[0017] Preferably, the resistance heating element is arranged without contact to the shielding element.

[0018] If the resistance heating element is arranged without contact, particularly without direct contact, with the shielding element, vibration decoupling of the fluidized bed, moving bed, or fluidized bed from the resistance heating element can be easily achieved. In other words, the resistance heating element can be positioned at a distance from the shielding element, but this distance need not be constant. The resistance heating element can be mounted or secured inside or outside the shielding element. Preferably, the resistance heating element also has no electrically conductive contact with the shielding element.

[0019] Preferably, the shielding element is made of a heat-resistant material, in particular metal and / or a ceramic material.

[0020] The heat-resistant material of the shielding element is capable of withstanding the high surface temperatures of the resistance heating element, even over extended periods of operation, without the thermal stress causing damage to the shielding element. Preferably, the shielding element is made of a material with high thermal conductivity to effectively transfer the heat generated by the resistance heating element into the fluidized bed or moving bed and thus heat the fluidized bed or moving bed.

[0021] In a preferred embodiment, at least one temperature sensor is provided in and / or inside the shielding element.

[0022] The at least one temperature sensor can easily detect the temperature inside or in the shielding element, thus enabling reliable monitoring of the thermochemical process taking place within the fluidized bed reactor. The at least one temperature sensor can, for example, be located in a bore formed in the shielding element.

[0023] Preferably, the shielding element is a tube open at one end and closed at the other end, with its closed end extending into the fluidized bed or moving bed or fluidized bed, or a tube open at both ends that penetrates the fluidized bed or moving bed or fluidized bed.

[0024] Preferably, the shielding element is a tube open at both ends and penetrates the fluidized bed, moving bed, or flowable bed. In this case, the resistance heating element can be designed as a rod-shaped element, preferably arranged centrally within the tube. The open tube end(s) can terminate inside or outside the reactor housing, and the tube or tube ends can be secured to the reactor housing, for example, by welding. The tube and the resistance heating element are advantageously arranged horizontally, but can also be arranged vertically or at an angle.

[0025] A bushing, especially a ceramic bushing, can be seated in each open pipe end, at least partially filling the gap between the resistance heating element and the pipe.

[0026] The bushing can provide support for the resistance heating element. However, it is also possible for at least a partial gap to remain between the resistance heating element and the bushing, allowing the bushing to act as insulation against the heat generated by the resistance heating element within the pipe. Simultaneously, the bushing can dampen pipe vibrations. Preferably, the bushing is made of a heat-resistant material. More preferably, the bushing is made of an electrically non-conductive material.

[0027] The bushings can be inserted into the open pipe ends and each has a ring flange that allows for easy centering and positioning of the bushings within the pipe. As described later, the bushings can also serve as fasteners for other elements, such as a protective conduit for electrical insulation located inside the pipe.

[0028] Preferably, the bushing is designed to dampen vibrations.

[0029] The bushing can itself dampen vibrations due to its shape and / or incorporate one or more vibration-damping elements. Preferably, the bushing is made of a composite material with vibration-damping properties. Advantageously, the bushing can have a layered structure with one or more damping layers. The bushing can also dampen vibrations due to its method of assembly or fastening.

[0030] The bushing can form a fixed or floating bearing for the resistance heating element.

[0031] If the bushing forms a floating bearing for the resistance heating element, any thermal expansions of the resistance heating element that may occur can be easily compensated for.

[0032] Preferably, the bushing has one or more notches and / or grooves.

[0033] The notches and / or grooves allow sensors, such as temperature sensors, to be easily inserted into the space between the resistance heating element and the shielding element.

[0034] Alternatively or in addition to mounting by means of bushing(s), the resistance heating element can be mounted in a bearing located laterally outside the reactor vessel.

[0035] If the storage of the resistance heating element is arranged laterally outside the reactor vessel, i.e. on a side that is external to a side wall of the reactor vessel, easy access to the storage can be ensured.

[0036] The bearing can be supported, in particular with vibration damping, on a foundation, especially a foundation of the reactor vessel.

[0037] In a preferred embodiment, the tube has an electrically insulating inner coating. FN0709P-WG-0007

[0038] 9 / 19

[0039] Leakage currents, which can occur at very high temperatures between the resistance heating element and the shielding element and can negatively affect measuring instruments or endanger operating personnel, can be avoided or prevented by the electrically insulating inner coating.

[0040] Alternatively or additionally, an electrically insulating protective tube can be arranged between the resistance heating element and the pipe.

[0041] The protective tube, similar to the shielding element or the tube itself, is preferably made of a heat-resistant but thermally conductive material. The protective tube can, for example, be a ceramic tube. The bushings located in the open ends of the tube can provide support for the protective tube. For example, the protective tube can be received in annular grooves formed in the bushings. If at least one temperature sensor is provided, the at least one temperature sensor can be arranged in or inside the protective tube.

[0042] Preferably, a gas or gas mixture is present in the shielding element and / or the shielding element is permeable to a gas or gas mixture.

[0043] The gas or gas mixture can prevent electrical conduction between the resistance heating element and the shielding element, or in a cavity within the heating element, by preventing the formation of ionized electrical charge carriers. In other words, the gas or gas mixture can prevent undesirable ionization effects during operation. The gas or gas mixture can also be used for improved electrical insulation even when an additional electrically insulating protective tube is located between the resistance heating element and the shielding element or the tube. FN0709P-WG-0007

[0044] 10 / 19

[0045] Advantageously, the gas is a noble gas, air, nitrogen or carbon dioxide, or the gas mixture consists of at least 40 percent by volume of a noble gas.

[0046] In particular, the remaining volume fractions of the gas mixture may consist of carbon dioxide and / or nitrogen.

[0047] By using these gases and / or gas mixtures, unwanted ionization effects and unwanted electrical currents can be effectively avoided during operation.

[0048] The reactor can have multiple tube-shaped shielding elements, each containing a resistance heating element. These multiple resistance heating elements can be connected in series or in parallel. The connection to a voltage source can be made at one end or at both ends of the multiple rod-shaped resistance heating elements.

[0049] The reactor can be enclosed in such a way that gas or a gas mixture can be introduced between the resistance heating element and the shielding element, and / or gas or a gas mixture can flow through the shielding element. In particular, the shielding element (the tube) can be routed through the enclosure in such a way that its ends are located outside the enclosure. This facilitates maintenance and replacement of the resistance heating element, even though each shielding element requires its own connection for introducing the gas or gas mixture. Alternatively, the ends of the shielding element, or in the case of multiple shielding elements, all ends of all shielding elements, can be located inside the enclosure, thus eliminating the need to introduce gas or a gas mixture into the shielding element.The shielding elements only need to expose the volume within the enclosure to the gas or gas mixture, i.e., only a single gas connection is required. FN0709P-WG-0007.

[0050] 11 / 19

[0051] In an alternative embodiment, the functional element can be an inductive heating element or a resistance heating element, arranged, in particular, laterally, outside the reactor vessel. A heat pipe, also known as a heat tube, can be arranged between the functional element and the fluidized bed.

[0052] If the functional element is designed as an inductive heating element, for example as an induction coil, a gap can be placed between the induction coil and the heat tube to prevent vibrations excited by the fluidized bed or moving bed from being transmitted from the heat tube to the inductive heating element. The same applies if the functional element is designed as a resistance heating element, for example as a resistance heating coil. Due to the physical separation of the fluidized bed or moving bed from the energized functional element, slag deposits on the functional element can be easily prevented.

[0053] Preferably, the electric heating device has thermal insulation.

[0054] The thermal insulation ensures that the heat generated by the electric heating device is kept as much as possible in the heat pipe and can be transferred to the fluidized bed or fluidized layer, and does not escape into the environment.

[0055] The heat pipe can be designed as a thermosiphon or as a pulsating heat pipe. It can be designed for a temperature range of 350°C to 1400°C. It is also possible for one functional element to be used for multiple heat pipes.

[0056] Further details, features and advantages of the invention will become apparent from the following description of a preferred embodiment with reference to the drawings. Figure 1 shows a schematic sectional view of a fluidized bed reactor according to a first embodiment of the invention;

[0057] Fig. 2 shows a schematic sectional view of a resistance heating element arranged inside a tube of a fluidized bed reactor according to a second embodiment of the invention;

[0058] Fig. 3 shows a front view of a bushing for supporting the tube shown in Fig. 2;

[0059] Fig. 4 shows a sectional view along line AA from Fig. 3; and

[0060] Fig. 5 shows a schematic sectional view of a fluidized bed reactor according to a third embodiment of the invention.

[0061] First embodiment

[0062] Figure 1 shows a schematic sectional view of a fluidized bed reactor 1 according to a first embodiment. The fluidized bed reactor 1 has a reactor vessel 4 with a side wall 5. Inside the reactor vessel 4, a fluidized bed 6 is formed, which is heated by an electric heating device in the form of a energized rod-shaped resistance heating element 10 in order to provide the thermal energy required for the endothermic reactions taking place within the fluidized bed 6.

[0063] As shown in Fig. 1, the resistance heating element 10 is formed within a shielding element 8 in the form of a tube that runs horizontally through the reactor vessel 4 and completely penetrates the fluidized bed 6. The tube is made of a heat-resistant material and has an electrically insulating inner coating 11. The resistance heating element 10 is guided into the shielding element 8 but does not completely penetrate the fluidized bed 6. It is also indicated that the resistance heating element 10 is spaced apart from the shielding element 8, i.e., it has a distance 12 from the shielding element 8. In the first embodiment, the rod-shaped resistance heating element 10 is arranged, in particular, centrally within the shielding element 8. In the first embodiment, the mounting of the resistance heating element 10 is realized laterally outside the reactor vessel 4.

[0064] The arrangement of the resistance heating element 10 shown in Fig. 1, within the shielding element 8 and thus outside the fluidized bed 6, prevents direct contact between the fluidized bed material and the resistance heating element 10. Consequently, the high surface temperatures of the resistance heating element 10 prevent the deposition of slag materials that can form from carbon-containing feedstocks and the fluidized bed material. Furthermore, the distance between the resistance heating element 10 and the shielding element 8 provides vibration decoupling, preventing vibrations excited by the fluidized bed 6, which could be transmitted to the reactor vessel 4 and / or the shielding element 8, from being transmitted to the resistance heating element 10. This ensures the safe operation of the fluidized bed reactor 1 and prevents mechanical failure of the resistance heating element 10.

[0065] Second embodiment

[0066] Fig. 2 shows a schematic sectional view of a resistance heating element 10, which is arranged inside a shielding element 8 in the form of a tube of a fluidized bed reactor 30 according to a second embodiment.

[0067] In contrast to the first embodiment, the resistance heating element 10 in the second embodiment is completely surrounded by the fluidized bed 6 (not shown in Fig. 2) and the reactor vessel 4, in particular by two in the reactor vessel FN0709P-WG-0007

[0068] 14 / 19 holder 4 formed feedthroughs 16, guided. Furthermore, in each open tube end of the shielding element 8, which is designed as a tube, a bushing 14, shown in more detail in Figures 3 and 4, is located, which fills the gap 12 between the resistance heating element 10 and the shielding element 8. In the second embodiment, the bushings 14 serve as bearings for the resistance heating element 10. To prevent vibrations excited by the fluidized bed 6, which can be transmitted to the reactor vessel 4 and / or the shielding element 8, from being transmitted to the resistance heating element 10 via the bushings 14, the bushings 14 are made of a vibration-damping composite material.

[0069] Third embodiment

[0070] Fig. 5 shows a schematic sectional view of a fluidized bed reactor 40 according to a third embodiment of the invention. In contrast to the first and second embodiments, the electric heating device consists of an electrically energized induction coil 20 arranged laterally outside the reactor vessel 4 and a heat pipe 18, which transfers the thermal energy generated in the heat pipe 18 in the region of the induction coil 20 into the fluidized bed 6.

[0071] By arranging the induction coil 20 outside the fluidized bed 6, it is possible to prevent slag from accumulating on the induction coil 20. Furthermore, a distance 12 between the induction coil 20 and the heat pipe 18 creates vibration decoupling, thus preventing vibrations excited by the fluidized bed 6, which could be transmitted to the reactor vessel 4 and / or the heat pipe 8, from being transmitted to the induction coil 20.

[0072] Reference symbol list

[0073] 1 Fluidized bed reactor reactor vessel

[0074] side wall

[0075] Flue layer

[0076] Shielding element

[0077] Resistance heating element

[0078] Interior coating

[0079] Distance

[0080] socket

[0081] implementation

[0082] heat pipe

[0083] Induction coil Fluidized bed reactor Fluidized bed reactor

Claims

1. Claims 1. Reactor (1 ; 30; 40) with a reactor vessel (4) in which a fluidized bed (6) or a moving bed or a fluidized bed can be formed, and an electric heating device for heating the fluidized bed (6) or the moving bed or the fluidized bed, characterized in that a functional element (10; 20) of the electric heating device, which is subjected to an electrical voltage for heating the fluidized bed (6) or the moving bed or the fluidized bed, is arranged outside the fluidized bed (6) or the moving bed or the fluidized bed and is arranged in a vibration-damped or vibration-decoupled manner relative to vibrations excited by the fluidized bed (6) or the moving bed or the fluidized bed.

2. Reactor (1 ; 30) according to claim 1 , characterized in that the functional element (10) is designed as a resistance heating element and is shielded from the fluidized bed (6) or the moving bed or the fluidized bed by means of a shielding element (8) penetrating into or passing through the fluidized bed (6) or the moving bed or the fluidized bed.

3. Reactor (1 ; 30) according to claim 2, characterized in that the resistance heating element is arranged without contact to the shielding element (8).

4. Reactor (1 ; 30) according to claim 3, characterized in that the shielding element (8) is made of a heat-resistant material, in particular metal and / or a ceramic material.

5. Reactor (1 ; 30) according to one of claims 2 to 4, characterized in that at least one temperature sensor is provided in and / or inside the shielding element (8).

6. Reactor (1; 30) according to one of claims 2 to 5, characterized in that the shielding element (8) is open at one end and closed at the other End closed tube which extends with its closed end into the fluidized bed (6) or the moving bed or the flowing bed, or is a tube open at both ends which penetrates the fluidized bed (6) or the moving bed or the flowing bed.

7. Reactor (1 ; 30) according to claim 6, wherein the shielding element (8) is a tube open at both ends that penetrates the fluidized bed (6) or the moving bed or the fluidized bed, wherein the tube and the resistance heating element are arranged vertically or obliquely.

8. Reactor (1 ; 30) according to claim 6 or 7, characterized in that a bushing (14), in particular a ceramic bushing, is located in each open tube end, at least partially filling the distance between the resistance heating element and the tube.

9. Reactor (1 ; 30) according to claim 8, characterized in that the bushing (14) is designed to dampen vibrations.

10. Reactor (1 ; 30) according to claim 8 or 9, characterized in that the bushing (14) forms a fixed bearing or floating bearing for the resistance heating element.

11. Reactor (1 ; 30) according to one of claims 8 to 10, characterized in that the bushing (14) has one or more notches and / or grooves.

12. Reactor (1 ; 30) according to one of claims 2 to 10, characterized in that the resistance heating element is mounted in a bearing arranged laterally outside the reactor vessel (4).

13. Reactor (1 ; 30) according to claim 12, characterized in that the bearing, in particular vibration-damped, is supported on a foundation. FN0709P-WG-0007 18 / 19 14. Reactor (1 ; 30) according to one of claims 6 to 13, characterized in that the tube has an electrically insulating inner coating (11 ).

15. Reactor (1 ; 30) according to one of claims 6 to 14, characterized by an electrically insulating protective tube arranged between the resistance heating element and the tube.

16. Reactor (1 ; 30) according to one of claims 2 to 15, characterized in that a gas or gas mixture is present in the shielding element (8) and / or the shielding element (8) is permeable to a gas or gas mixture.

17. Reactor (1 ; 30) according to claim 16, characterized in that the gas is a noble gas, air, nitrogen or carbon dioxide or the gas mixture consists of at least 40% by volume of a noble gas.

18. Reactor (1 ; 30) according to claim 17, characterized in that the remaining volume fractions of the gas mixture consist of carbon dioxide and / or nitrogen.

19. Reactor (40) according to claim 1 , characterized in that the functional element (10; 20) is an inductive heating element or a resistance heating element arranged outside the reactor vessel (4), and a heat tube (18) is arranged between the functional element (10; 20) and the fluidized bed (6).

20. Reactor (40) according to claim 19, characterized in that the electrical heating device has thermal insulation.

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