Cyclone for thermal system

Abstract

To provide a cyclone that reduces or prevents formation of a heap at an inlet channel.SOLUTION: A cyclone 120 for separating a solid material S from a mixture M of the solid material S and a gaseous substance G comprises a cylindrical body 122 having a central axis in a first downward direction Sz, and an inlet channel 200. The cyclone is configured to let out the solid material S in the first direction Sz. An interior of the inlet channel 200 tapers in the first direction Sz towards a bottom 210 of the inlet channel 200. The cyclone also comprises nozzles 220 arranged at the bottom 210 of the inlet channel 200, the nozzles 220 being configured to feed a gas G to the inlet channel 200 for enhancing a flow of the solid material S at the bottom 210 of the inlet channel 200.SELECTED DRAWING: Figure 2a

Description

[Technical field]

[0001] The present invention relates to thermal systems such as pyrolysis reactors, gasification reactors, boilers including circulating fluidized bed boilers and bubbling fluidized bed boilers. The present invention relates to a cyclone suitable for such systems. The present invention relates to a cyclone suitable for separating solid materials from a mixture of solid and gaseous materials. [Background technology]

[0002] Cyclones are commonly used to separate solid materials from a mixture of solid and gaseous materials. Cyclones may be used in thermal systems such as circulating fluidized bed boilers. As an example, FIG. 3 of US Pat. No. 6,299,333 discloses a circulating fluidized bed boiler including, among other things, a furnace and a cyclone. The gist of FIG. 3 of US Pat. No. 6,299,333, including the furnace 110 and the cyclone 120, is reproduced as FIG. 1 herein. The mixture M present in the furnace 110 enters the cyclone 120 through an inlet channel 200, in which both the solid material S and the gaseous material G are separated from the mixture M. Generally, as shown in FIG. 1, the heavy solids (i.e., the solid material S) are collected on the wall of the cyclone 120 by centrifugal force and fall downwards by gravity. In contrast, the gaseous material G can be discharged from the top of the cyclone 120.

[0003] It was found that at the bottom of the inlet channel 200, a heap 990 containing a part of the solid material S often accumulates, as shown in FIG. 1. The heap 990 has several disadvantages. First, to ensure the proper functioning of the system, it is necessary to remove the heap 990 from time to time. Removal of the heap 990 is a complex task, since the heap 990 can be very large (several cubic meters) and can be very hot (several hundred °C) during use. Therefore, in order to remove the heap 990, it must be cooled, which can take several days. Furthermore, upon cooling, the material of the heap 990 can be sintered into a monolithic solid piece that is difficult to remove. Secondly, the density of the solid material of the heap 990 can be comparable to that of sand, for example about 2 tons per cubic meter. If the size of the heap 990 is several cubic meters, the weight of the heap 990 must be taken into account when designing the system to withstand the increase in weight of the system due to the formation of the heap 990. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] European Patent No. 1831604 Summary of the Invention [Problem to be solved by the invention]

[0005] For at least these reasons, there is a need to reduce the tendency for deposits 990 to form in the inlet channels 200 of cyclones 120, especially in thermal systems. [Means for solving the problem]

[0006] The inventors have found that the tendency of deposits 990 to form in the inlet channel 200 of the cyclone 120 can be reduced by providing one or more nozzles 220 at the bottom 210 of the inlet channel 200 configured to supply gas to the inlet channel 200 to enhance the flow of solid material S at the bottom 210 of the inlet channel 200. In addition, the shape of the inlet channel is designed to taper towards the bottom 210 of the inlet channel 200, thereby collecting the solid material at the nozzles 220.

[0007] The nozzles may be configured to blow air or other gas to enhance the flow of solids toward the interior of the cyclone. The bottom 210 of the inlet channel 200 may be sloped to enhance the flow of solids toward the interior of the cyclone.

[0008] The invention is set out in more specific terms in claim 1. Preferred embodiments are disclosed in the dependent claims. These and other embodiments are described in the specification and drawings. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 shows a prior art circulating fluidized bed boiler. [Figure 2a] FIG. 2a shows a first embodiment of a cyclone. [Figure 2b] FIG. 2b shows a second embodiment of the cyclone. [Figure 2c] FIG. 2c shows in detail a first embodiment of the cyclone and some orientations. [Figure 3a] FIG. 3a shows a first cross-section of an inlet channel of a cyclone according to a first embodiment. [Figure 3b] FIG. 3b shows a first cross section of an inlet channel of a cyclone according to a second embodiment. [Figure 4a] FIG. 4a shows the orientation and dimensions of a portion of FIG. 3a in more detail. [Figure 4b] FIG. 4b shows the orientation and dimensions of a portion of FIG. 3b in more detail. [Diagram 5] Figures 5a and 5b show a cross section of an inlet channel of a cyclone according to an embodiment, for example the first embodiment or the second embodiment, the cross section being perpendicular to the first cross section. [Figure 6] 6a-6c show cross sections of an inlet channel of a cyclone according to an embodiment, for example the first embodiment or the second embodiment, the cross sections being perpendicular to the first cross section. [Figure 7a] Figure 7a shows a first cross section of an inlet channel of a cyclone, which is also provided with nozzles in its wall, but which is otherwise substantially similar to the first embodiment of Figure 3a. [Figure 7b] Figure 7b shows a first cross section of an inlet channel of a cyclone, which is also provided with nozzles in its wall, but which is otherwise substantially similar to the first embodiment of Figure 3b. [Figure 8] FIG. 8 shows a cross section of an inlet channel of a cyclone according to an embodiment, for example the first embodiment or the second embodiment, the cross section being perpendicular to the first cross section and the angle being more detailed. [Figure 9] 9a-9d show cross-sections of an inlet channel of a cyclone according to an embodiment, where the walls of the inlet channel comprise heat transfer tubes covered with mortar. [Figure 10] FIG. 10 shows a cross section of a cyclone including the inlet channel of the cyclone, the cross section being substantially horizontal. [Figure 11] FIG. 11 shows a thermal system in which the same gas (eg, air) is fed to both the reactor (eg, furnace) and the nozzle of the inlet channel of the cyclone. [Figure 12] Figure 12 shows a thermal system that feeds recycled gas into a nozzle in the inlet channel of a cyclone, where the recycled gas is separated from the mixture.

[0010] In the drawing, the direction Sz is disposed downward in typical use, Sx is perpendicular to Sz and horizontal in typical use, substantially parallel to the direction of flow of the mixture M in the inlet channel, and Sy is perpendicular to both Sx and Sz. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] 2a to 10 show an embodiment of a cyclone 120. The cyclone 120 is suitable and configured to separate a solid substance S from a mixture M. The mixture comprises both a solid substance S and a gaseous substance G, resulting in a mixture M of solid substances S and gaseous substances G. The principle of operation of the cyclone is cyclonic separation, which is well known to those skilled in the art and can be found in textbooks.

[0012] 2a-2c, the cyclone 120 includes a cylinder 122 having a central axis in a first direction Sz. In typical use, the first direction Sz is directed in the same direction as gravity, i.e., downward. The term "cylinder 122" refers to a body having a substantially circular interior 123, even if the exterior surface of the wall of the body 122 has a different shape. The cyclone 120 includes an inlet channel 200. The inlet channel 200 is configured to allow the mixture M to enter the cylinder 122. In particular, the inlet channel 200 is configured to allow the mixture M to enter the interior 123 of the cylinder 122. The inlet channel 200 has an inlet 201 for receiving the mixture M and an outlet 202 opening into the interior 123 of the cylinder 122. The inlet 201 and the outlet 202 are shown at least in FIGS. 5a-6b.

[0013] The inlet channel 200 extends in a second direction Sx, which is perpendicular to the first direction Sz. Moreover, the inlet channel 200 is configured to feed the mixture M into the cylinder 122 in a direction approximately parallel to the second direction Sx. More precisely, the inlet channel 200 is configured to feed the mixture M into the cylinder 122 in a feed direction (FD, see FIG. 10), the normal projection of the feed direction FD onto a plane having a normal to the first direction Sz is parallel to the second direction Sx (see FIG. 10). However, with reference to FIGS. 5a-6b, the feed direction FD may also have a component in the first direction Sz, as is evident by the direction DT along which the solid material moves along the bottom 210. As mentioned above, in one embodiment, the first direction Sz is downward vertical. So, in this embodiment, the second direction Sx is parallel to the normal projection of the direction of the feed direction FD, which is on a horizontal plane. In the above, the feed direction is the average direction of the mixture M in use, which flows through the inlet channel 200 from the inlet 201 to the outlet 202 .

[0014] Accordingly, the outlet 202 is disposed in at least the second direction Sx from the inlet 201. In addition to being disposed in the positive second direction Sx, the outlet 202 may be disposed, for example, below the inlet 201. In such an embodiment, the outlet 202 may also be disposed in the first direction Sz from the inlet 201. More precisely, the outlet 202 is disposed in a direction from the inlet 201 having a positive component in the first direction Sz and in the second direction Sx. As an example, the bottom 210 of the inlet channel may be inclined towards the interior 123 of the cylinder 122 (see Figures 5a-6b), and the ceiling of the inlet channel 200 may be inclined similarly to the bottom 210 (not shown).

[0015] As defined above, the first direction Sz and the second direction Sx also define a third direction Sy that is perpendicular to both Sz and Sx. In the drawings (e.g., 2a), the directions follow the usual right-hand rule: Sz = Sx x Sy, where x indicates the vector product of the two directions (i.e. vectors) Sx and Sy.

[0016] A nozzle 220 or nozzles 220 are provided at the bottom of the inlet channel 200 with the aim of reducing the tendency of the deposit 990 to form. Thus, the cyclone includes a nozzle 220 or several nozzles 220 arranged at the bottom 210 of the inlet channel 200. The nozzle 220 is configured to supply gas to the inlet channel 200 in order to promote the flow of the solid material S at the bottom 210 of the inlet channel 200. When air or other gas is supplied to the inlet channel 200 through the nozzle 220, the flow of the solid material S is promoted and the tendency of the deposit 990 to form is reduced. Due to the fluidization effect provided by the gas supplied through the nozzle 220, instead of the deposit 990 forming, the solid material flows into the interior 123 of the cylinder 122 together with the mixture M in the inlet channel 200.

[0017] However, a small deposit or a number of small deposits may form in the area of ​​the bottom 210 of the inlet channel 200 that is not affected by the nozzle 220. The shape of the inlet channel 200 is therefore designed such that the interior 239 of the inlet channel 200 tapers in a first direction Sz towards the bottom 210 of the inlet channel 200. The tapered shape of the inlet channel 200 thus forms a funnel that collects solid material at the bottom 210 of the inlet channel 200, where the nozzle 220 is provided. See Figures 2a, 2b, 3a and 3b. With reference to Figures 7a and 7b, the shape does not need to be tapered over the entire height of the inlet channel (even close to the bottom 210). As shown in Figures 7a and 7b, the nozzle 220 may be provided in a bottom channel bounded by a wall that includes a substantially vertical portion. With reference to Figures 9a and 9c, the outer surface of the inlet channel 200 does not need to be tapered in the first direction Sz.

[0018] Thus, if the solid material does not flow directly into the interior 123 of the cylinder 122, it will fall by gravity towards the bottom 210 of the inlet channel 200, and the solid material will be in a state of flow due to the gas supplied by the nozzle 220, which will direct the solid material at least along the bottom 210 into the interior 123. Furthermore, the tapered shape of the interior 239 of the inlet channel will funnel the solids towards the nozzle 220. As an example, Figures 5a and 5b show the direction DT in which the solid material travels along the bottom 210.

[0019] In order to enhance the collection of solid material at the bottom 210, the shape of the inlet channel 200, and in particular the shape of its interior 239, should be moderately and sharply tapered towards the bottom 210. At the same time, however, there are two other design factors to be considered. First, the width of the inlet channel 200, measured at the height of the bottom 210, should not be too large to prevent the formation of deposits next to the nozzle 220 on the bottom 210. In addition, preferably, the shape of only the lower part of the inlet channel 200 should be tapered towards the bottom 210. Conversely, the upper part of the inlet channel 200 preferably has a substantially constant width. This is preferred from the point of view of the throughput of the inlet channel 200. However, with reference to Figs. 7a and 7b, the lowest part of the interior 239 does not need to be tapered.

[0020] For these reasons and with reference to Figures 3A and 3b, in one embodiment, the inlet channel 200 of the cyclone 120 includes walls 230, 231 that limit the interior 239 of the inlet channel 200. The walls 230, 231 are designed to form a taper, as described above. Thus, at least one of the walls 230, 231, namely the first wall 231, the first wall indicated by reference number 231 in Figures 3a and 3b, extends from the bottom 210 of the inlet channel 200 such that the surface of the wall 231 facing the interior 239 is inclined. Thus, at least a portion of the first wall 231 extends at an angle. The wall 231 extends from the bottom 210 of the inlet channel 200 such that a first angle α between (i) a first normal N1 of at least a portion of the surface of the first wall 231 extending from the bottom 210 of the inlet channel 200 and (ii) a first direction Sz is between 110° and 160°. Here, the surface of the wall 231 refers to a surface that limits the interior 239 of the inlet channel 200. Therefore, the first normal N1 faces towards the interior 239 of the inlet channel 200. Figures 3a and 3b show a cross section of the inlet channel 200, the cross section being on a plane Px, which is shown in Figure 2c. As shown in Figures 3a and 3b, the inclined portion of the first wall 231, in one embodiment, extends from the bottom 210. However, as shown in Figures 7a and 7b, the inclined portion of the first wall 231, in one embodiment, extends from a vertical portion extending from the bottom 210.

[0021] 3a, in one embodiment, the first direction Sz is downwards and the angle between the first normal N1 and the horizontal plane may be, for example, 20° to 70°. A minimum value of this angle (and the first angle α) ensures that the solid material is collected at the bottom 210, and a maximum value of this angle (and the first angle α) ensures a suitable width of the bottom of the inlet channel 200 and / or a suitable height of the taper.

[0022] 3a, in one embodiment, the inlet channel 200 comprises two opposing walls 231 such that (i) a first normal N1 of at least a portion of the surface of a first wall of the opposing walls 231 extending from the bottom 210 of the inlet channel 200 and (ii) a first angle α between the first normal N1 of at least a portion of the surface of a first wall of the opposing walls 231 extending from the bottom 210 of the inlet channel 200 and (ii) a first direction Sz is within the upper and lower limits disclosed above, and (i) an angle between a normal of at least a portion of the surface of a second wall of the opposing walls 231 extending from the bottom 210 of the inlet channel 200 and (ii) a first direction Sz is within the upper and lower limits disclosed above. In the embodiment of FIG. 3a, the bottom 210 of the inlet channel 200 may be substantially at the center of the inlet channel 200 in the third direction Sy. For example, the bottom 210 may be positioned such that a width of a first portion of the inlet channel 200 disposed on a first side of the bottom 210 is 75%-125% of a width of a second portion of the inlet channel 200 disposed on a second side of the bottom 210, the widths of these portions being defined in a third direction Sy, where the first and second sides of the bottom 210 are disposed on either side of a centerline of the inlet channel 200, the centerline being centered in the third direction Sy.

[0023] In such a case, the opposing walls 231 may be substantially symmetrical about the central plane of the inlet channel, as shown in Figure 7a, however, as shown in Figures 3a and 4a, the walls need not be symmetrical in such a way.

[0024] 3b, in one embodiment, the inlet channel 200 includes only one opposing wall 231 such that the angle α between (i) a first normal N1 of at least a portion of the surface of the first of the opposing walls 231 extending from the bottom 210 of the inlet channel 200 and (ii) the first direction Sz is within the upper and lower limits disclosed above. The opposing wall can be, for example, substantially vertical, as shown in FIG. 3b.

[0025] The purpose of the slope of the surface of the wall 231 is to guide the solid material to the bottom 210 of the inlet channel 200. Regardless of the magnitude of the first angle α, the accumulation of solid material on the walls 230, 231 of the inlet channel 200 can be prevented or at least reduced by providing one or more auxiliary nozzles 222 on the walls 230, 231 to further fluidize the solid material and promote the flow of the material. Thus, in one embodiment, the cyclone 120 includes one or more auxiliary nozzles 222 provided on at least a portion of the wall having the first normal N1. Such an auxiliary nozzle 222 is shown in Figures 7a and 7b. The auxiliary nozzles 222 are configured to supply gas to the inlet channel 200 to promote the flow of the solid material S in the inlet channel 200. In particular, the auxiliary nozzle 222 is configured to supply gas to the inlet channel 200 to promote a flow of solid material S in the inlet channel 200 at a position of the inlet channel 200 where the shape of the inlet channel 200 tapers in a first direction Sz towards a bottom 210 of the inlet channel 200. If the first angle α is selected from the lower end of the above range or is smaller, the risk of solid material depositing on the wall 231 increases if the auxiliary nozzle 222 is not provided.

[0026] Regarding the appropriate width of the bottom 210, Fig. 4a and Fig. 4b show the width W210 of the bottom 210. Here, the width W210 is defined in the third direction Sy defined above. With respect to the term "bottom", in one embodiment, the bottom 210 of the inlet channel 200 includes a portion having a second normal N2 facing the interior 239 of the inlet channel 200 and having no component in the third direction Sy. Here, a portion refers to a surface. Thus, the bottom 210 of the inlet channel 200 includes a portion whose surface has a second normal N2 facing the interior 239 of the inlet channel 200 and has no component in the third direction Sy. Thus, the surface of the portion may be horizontal or inclined with respect to the interior 123 of the cylinder 122.

[0027] Regarding the expression that the second normal N2 has no component in the third direction Sy, as is well known, in a coordinate system, any vector (including a directional vector) can be expressed by a combination of its components. In this case, the coordinate system is defined by its base vectors, and any vector can be expressed as a linear combination of the base vectors. Therefore, any vector can be decomposed into its components. In this description, the first, second and third directions (Sz, Sx and Sy) define a coordinate system. If the second normal N2 has no component in the third direction Sy and the second normal N2 is decomposed into components of the coordinate system defined by Sz, Sx and Sy, the component corresponding to Sy will be 0. However, the bottom 210 of the inlet channel 200 does not need to include a portion that has the second normal N2 facing the interior 239 of the inlet channel 200 and has no component in the third direction Sy.

[0028] Similarly, if another direction (e.g., DT) has a positive component in a particular direction that is one of the directions of the basis vectors (Sz, Sx, and Sy) of the coordinate system, then the component associated with the particular direction will be positive and not zero.

[0029] Regarding the width W of the bottom 210, in one embodiment, the width W of the bottom 210, for example the width W of the portion of the bottom 210 having the second normal N2, is at most 50% of the width W239 of the interior 239 of the inlet channel 200. Here, the width W210 is defined in the third direction Sy. Furthermore, the width W239 of the interior 239 of the inlet channel 200 is defined in the third direction Sy. As shown in Figures 4a and 4b, the width W239 of the interior 239 of the inlet channel 200 refers to the width measured at the top of the inlet channel 200. The width W239 of the interior 239 may be the maximum width of the interior 239 in the third direction Sy.

[0030] As shown in Figures 3a and 4b, particularly when the width W210 of the bottom 210 is large, for example close to or up to 50% of the width W239 of the interior 239, it may be necessary to provide multiple nozzles 220 on the bottom 210, for example side by side (in the third direction Sy), to avoid deposits forming on the sides of the nozzles 220.

[0031] In an embodiment, the width W210 of the bottom 210 is at most 35% of the width W239 of the interior 239 of the inlet channel 200. The width W210 of the bottom 210 can be, for example, at least 5% of the width W239 of the interior 239 of the inlet channel 200.

[0032] 4a and 4b, in one embodiment, at least the outlet of the nozzle 220 is arranged above the bottom 210, for example above a portion of the bottom 210 having the second normal N2. Thus, in one embodiment, the nozzle 220 is provided (or a plurality of nozzles 220 are provided) on at least a portion of the bottom 210 having the second normal N2. Of course, even if the cyclone 120 is provided with the nozzle 220, the bottom 210 does not necessarily have to include a portion having a surface having the second normal N2 as defined above.

[0033] When forming the walls 230, 231, the walls 230, 231 preferably include heat transfer tubes 242 for recovering heat from the inlet channel 200. The heat transfer tubes 242 are shown in Figures 9a-9d. However, the environment within the inlet channel 200 is harsh as the flowing solid material tends to erode the walls 230, 231 of the inlet channel 200. Thus, if the heat transfer tubes 242 themselves are exposed to the flowing solid material, they will erode quickly. To prevent erosion, in one embodiment, the heat transfer tubes 242 of the walls 230, 231 are covered with mortar 244 at least on the side facing the interior 239 of the inlet channel.

[0034] Thus, in one embodiment, the bottom 210 of the inlet channel 200 includes a heat transfer tube 242 covered with mortar 244. Furthermore, preferably, the wall 231 having at least a portion with the first normal N1 includes a heat transfer tube 242 covered with mortar 244.

[0035] The thickness of the mortar 244 does not have to be constant. As an example, Figures 9a and 9b show an embodiment in which the bottom 210 is substantially centered in the inlet channel 200 in the third direction Sy. With reference to Figures 9a and 9b, in one embodiment, the walls 230, 231 include a heat transfer tube 242 covered with mortar 244, the mortar 244 being disposed at least between the interior 239 of the inlet channel and the heat transfer tube 242 to protect the heat transfer tube 242 from erosion.

[0036] To have adequate protection against erosion, the thickness of the mortar 244 on the heat transfer tubes 242 may be at least 20 mm, such as at least 40 mm.

[0037] 9a, in one embodiment, the thickness of the mortar 244 is adapted so that, even though the longitudinal direction of the heat transfer tube 242 constituted by the wall 231 is parallel to the first direction Sz, an inclined surface of the wall 231 is formed. This is obtained by using a thick layer of mortar 244 near the bottom 210 of the inlet channel and, conversely, a thin layer of mortar 244 above the bottom 210.

[0038] As detailed in Fig. 9b, in one embodiment, the thickness of the mortar 244 can be substantially constant, so that the sloping surface of the wall 231 is formed by the bending point of the heat transfer tube 242, and the heat transfer tube 242 is covered by using a substantially constant thickness of mortar 244 to cover the heat transfer tube 242, as shown in Fig. 9b.

[0039] The above statement regarding the thickness of the mortar 244 is applicable to some embodiments in which the bottom 210 is disposed on one side of the inlet channel 200 in the third direction Sy, as shown in Figures 9c and 9d. For example, as shown in Figure 9c, the heat transfer tube 242 may extend in the first direction Sz (i.e., may have a longitudinal direction) even though the surface of the wall 231 is inclined. As another example, as shown in Figure 9d, the heat transfer tube 242 may include a bend such that the surface of the wall 231 is inclined even though the thickness of the mortar 244 is substantially constant.

[0040] With reference to Figures 5a, 5b, 6a, 6b, 6c and 8, the bottom 210 may also be inclined towards the interior 123 of the cylinder 122 of the cyclone 120. Thus, in one embodiment, at least a portion of the bottom 210 of the inlet channel 200 is inclined such that material moving along the bottom 210 towards the cylinder 122 moves in a direction DT having a positive component in the first direction Sz (and by definition a component in the second direction Sx as well). Thus, in a typical use and in one embodiment, the material moves towards the outlet 202 and at the same time at least slightly downwards. The material moving along the bottom 210 towards the cylinder 122 moves from the inlet 201 to the outlet 202 (see Figures 5a-6b). Figures 5a-6b show a cross section of the inlet channel 200, the cross section being on a plane Py, which plane Py is shown in Figure 2c.

[0041] In the embodiment of Fig. 5a, the entire bottom 210 is inclined as described above. Therefore, material moving from the inlet 201 towards the cylinder 122 (i.e. towards its interior 123) also moves in a positive first direction Sz. Along these lines, the direction DT along which the material on the bottom 210 moves has a positive component in the first direction Sz. What was said above about separating a vector into its components in a coordinate system applies.

[0042] In the embodiment of Figure 5b, only the portion of the bottom 210 closer to the cylinder 122 is sloped in the manner described above. However, the portion of the bottom 210 closer to the reactor 810 (e.g., furnace 110) may be sloped in the opposite direction, so that material that may tend to accumulate on the sides of the reactor 810 at the bottom 210 of the inlet channel flows back along the bottom 210 into the reactor 810.

[0043] For the magnitude of the slope of the bottom 210, see Figure 8. Thus, in one embodiment, the bottom 210 of the inlet channel 200 includes a portion having a third normal N3 that faces the interior 239 of the inlet channel 200. The third normal N3 has a first component in the first direction Sz and a second component in the second direction Sx. The third normal N3 may also have a component in the third direction Sy.

[0044] Due to the inclination of the bottom, the third normal N3 forms a smaller angle with the positive second direction Sx than with the negative second direction -Sx, even though the angles with the positive / negative second directions -Sx, -Sx are not indicated by reference signs, see FIG.

[0045] Regarding tilting, this type of tilting is not necessary since the gas provided by the nozzle 220 can drive the solid material into the interior.

[0046] However, in one embodiment, the vector defined by the first component (of the third normal N3) and the second component (of the third normal N3) forms a second angle β between 135 and 180°. Thus, the angle of the surface of the bottom 210 with respect to the horizontal may be between 0 and 45°. See FIG. 8. However, the bottom 210 may be at least slightly inclined. Thus, in one embodiment, the second angle β is between 135 and 178°. Thus, the angle of the surface of the bottom 210 with respect to the horizontal may be between 2 and 45°. The second angle β is shown in FIG. 8. This definition excludes possible inclinations of the bottom 210 in the third direction Sy by defining the second angle with only two components of the third normal N3 defined above. For example, if the inlet channel walls 231 (see FIG. 3a or FIG. 7a) extend to the bottom 210 to form a sharp V-shape with a substantially zero width W210, then a slope of the bottom 210 in the third direction Sy is also evident, but does not necessarily affect guiding the material towards the interior 123. For these reasons, the third component corresponding to the direction Sy of the third normal N3 is omitted from the above definition.

[0047] Regarding the slope, the surface of the bottom may be formed with mortar, and the thickness of the mortar does not have to be constant. So, even if the bottom 210 is formed of a tube covered with mortar, the tube itself can be arranged so that there is no slope or even some slope of the surface formed by the tube itself towards the inlet 201. A thinner layer of mortar may then be applied near the outlet 202 and a thicker layer of mortar may be applied near the inlet 201, such that the slope of the surface formed by the mortar is within the upper and lower limits disclosed above. The variation of the thickness of the mortar at the bottom 210 is not shown. However, the same principle applies to the bottom 210, as shown for the wall in Figures 9a-9d.

[0048] As detailed above, the purpose of the nozzle 220 is to fluidize the solid material on the bottom 210 in order to improve the movement of the solid material into the interior 123 of the cylinder 122. Additionally, as detailed above, the movement can be further improved by positioning the bottom 210 so that it is sloped towards the interior 123.

[0049] Further, as shown in Figs. 5a-6c and 8, an embodiment includes a plurality of nozzles 220 in the bottom 210, the plurality of nozzles 220 being arranged consecutively at least in the second direction Sx. This applies regardless of the magnitude of the second angle β, which may be, for example, 180 degrees or less in this embodiment, as detailed above. The plurality of nozzles 220 also aids in fluidizing the solid material in the bottom 210, substantially the entire bottom 210. The nozzles 220 may be arranged at different heights in the first direction Sz. The nozzles 220 do not have to direct the solid material, but may be oriented to direct the solid material towards the interior 123.

[0050] Thus, the flow of material on the bottom 210 may be further promoted by the nozzle 200 by orienting the nozzle 220 to move the solid material towards the interior 123. For example, in one embodiment, the nozzle 220 is configured to supply gas in a direction that forms an angle of at most 60° (e.g., at most 45°) with the second direction Sx. Thus, in one embodiment, the nozzle 220 is configured to supply gas to the inlet channel 200 such that the supply of gas promotes the flow of material on the bottom 210 of the inlet channel 200 towards the interior 123 of the cylinder 122 of the cyclone 120.

[0051] 6a-6c show an embodiment in which the nozzle 220 is shaped such that the gas delivered by the nozzle 220 directs the solid material towards the interior 123. As shown in Figs. 6a-6c, the direction of the gas exiting the nozzle 220 forms a small angle with the second direction Sx to direct the solid material towards the interior 123. This small angle is within the ranges disclosed above.

[0052] Further, with reference to Figures 6b and 6c, an embodiment includes several nozzles 220. Furthermore, the heights of the nozzles are arranged relative to each other such that the nozzles closer to the interior 123 of the cylinder 122 are also located in the positive first direction +Sz, i.e. further down in normal use. Similarly, the nozzles closer to the reactor 810 are also located in the negative first direction -Sz, i.e. further up in normal use. This has the effect that the nozzles further away from the interior 123 spray the fluidizing gas and solid material above the nozzles closed to the interior. Thus, the nozzles themselves do not form an obstacle to the flow of material, thereby improving the movement of solids in the inlet channel. Furthermore, erosion of the nozzles can be reduced.

[0053] The cyclone 120 is preferably arranged as part of a thermal system. Examples of thermal systems include fluidized bed boilers, gasification reactors, and pyrolysis reactors. Thus, one embodiment of the present invention is a thermal system including the cyclone 120. Examples of thermal systems are shown in Figures 11 and 12. The thermal system includes a reactor 810 configured to produce a mixture M of a solid substance S and a gaseous substance G. The thermal system is configured to direct the mixture M from the reactor 810 to an inlet channel 200 of the cyclone 120.

[0054] In one embodiment, the reactor 810 includes one of the furnaces 110 of the circulating fluidized bed boiler 100, a pyrolysis reactor, a gasification reactor, and a furnace of a bubbling fluidized bed boiler. FIG. 11 shows an example where the reactor 810 includes the furnace 110 of the circulating fluidized bed boiler 100. In such an embodiment, the main function of the cyclone is to separate the bed material and the flue gas from their mixture. FIG. 12 shows an example where the reactor 810 includes a pyrolysis reactor of the circulating fluidized bed type. Although not shown, an embodiment of the cyclone can be used, for example, to separate fly ash from the flue gas, which is generated, for example, by a bubbling fluidized bed boiler. In such an embodiment, the main function of the cyclone is to separate ash (e.g., fly ash) from the flue gas.

[0055] As is known, cyclones work on the basis of cyclonic separation. Thus, in a cyclone, solid substances S and gaseous substances G are separated from a mixture M by means of rotational effects and gravity. In order to increase the rotational effect and thus improve the cyclonic separation, the inlet channel 200 is preferably arranged with respect to the cylinder 122 in such a way that the direction of movement of the mixture M is at least somewhat tangential at that position when it leaves the inlet channel 200 and enters the interior 123 of the cylinder 122. The term tangential refers to the tangential plane of the interior 123 of the cylinder 122. See FIG. 10. In FIG. 10, the first direction Sz is perpendicular to the plane shown in the figure and points away from the paper. Correspondingly, FIG. 10 shows the feed direction FD, the second direction Sx and the third direction Sy, as described above. More precisely, for the illustration of FIG. 10, the drawing shows only the projection of the feed direction FD onto the plane of FIG. 10, which defines the second direction Sx, as detailed above. Note that in FIG. 10, due to the different position of the inlet channel 200 relative to the interior 123, the vortex forms in a different direction (e.g., counterclockwise when viewed from above) within the interior 123 than in the embodiment of FIGS. 2a and 2c (the vortex is a clockwise vortex when viewed from above).

[0056] 10, in one embodiment, the inlet channel 200 extends in the second direction Sx and is configured to feed the mixture M into the cylinder 122 in a feed direction FD. As detailed above, the feed direction FD has a component in the second direction Sx and may have a component in the first direction Sz. However, by definition of the second direction Sx (see above), the feed direction FD does not have a component in the third direction Sy. Thus, the inlet channel 200 is configured to feed the mixture M into the cylinder 122 at least in the second direction Sx.

[0057] The inlet channel 200 has an inlet 201 for receiving the mixture M and an outlet 202 opening into the interior 123 of the cylinder 122 to allow the mixture M to enter the interior 123. What has been said above with respect to the position of the outlet 202 relative to the inlet 201 applies. To enhance the rotation effect in the cylinder 122, in one embodiment the outlet 202 is arranged in a position such that the second direction Sx forms a third angle γ of at most 45° with the tangent direction Dtan of the cylinder 122. The tangent direction Dtan is defined here at the position of the outlet 202 in the interior 123. Here, the tangent direction Dtan refers to a direction tangent to the interior 123 of the cylinder 122, which has no component in the first direction Sz (i.e. without taking into account the axial direction of the surface of the cylindrical interior 123). The tangent direction Dtan at the position of the outlet 202 is shown in FIG. 10. It will be appreciated that the tangent plane of the cylinder 122 defines two such directions that have no component in the first direction. One of these directions is indicated by the reference symbol Dtan in Fig. 10, and the other of these directions is the opposite of that direction. In line with what has been said above, i.e., in one embodiment, the angle γ is at most 45 degrees, so that the angle between the second direction Sx and the other tangent direction (not shown) can be at least 135°, since these angles are adjacent angles, as indicated by the dashed lines near the symbols Sx and γ in Fig. 10.

[0058] Still referring to FIG. 10 to clarify the relative positions of the outlet 202 and the cylinder 122 in an alternative manner that can be combined with what has been explained above with respect to the third angle γ, in one embodiment, a cyclone 120 that may be part of a thermal system includes walls 230, 231, 232 that limit an interior 239 of the inlet channel 200. One of these walls may be referred to as a second wall 232. Referring to FIG. 10, the second wall 232 is attached to the cylinder 122. It should be noted that such a second wall 232 is also shown at least in FIGS. 3a, 3b, 4a, 4b and 9a-9d.

[0059] The second wall 232 is attached to the cylinder 122 such that the portion of the second wall 232 that is attached to the cylinder 122 has a fourth normal N4, see FIG. 10. Here, the fourth normal N4 refers specifically to the portion of the second wall that faces the interior.

[0060] 10, the attachment point between the cylinder 122 and the second wall 232 is the point where the cylindrical shape of the cylinder changes to the planar shape of the second wall 232. However, the second wall 232 has a curved shape, for example with a radius of curvature larger than the radius of the cylinder 122.

[0061] 10, the cylinder 122, and in particular its interior 123, defines a tangent plane Pt at the location where the second wall 232 is attached to the cylinder 122. Furthermore, the second wall 232 is disposed relative to the cylinder such that the tangent plane Pt has a fourth normal N4. That is, the normal of the tangent plane Pt is parallel to the fourth normal N4, i.e., the normal of the portion of the second wall 232 that is attached to the cylinder. This also improves the generation of vortices within the interior 123 of the cylinder, because it allows at least a portion of the material entering the interior 123 to enter the interior at a velocity that has a substantially tangential direction.

[0062] More preferably, at least the bottom 210 is located relatively close to the second wall 232 to further improve vortex generation within the cylindrical interior 123 .

[0063] More specifically, the inlet channel 200 includes an outlet 202 that opens into the interior 123 of the cylinder 122. The outlet 202 includes a portion of the bottom 210 of the inlet channel. For example, FIG. 10 illustrates a line L that defines the bottom 210. 210 The line may be, for example, a portion of the inlet channel 210 with a sloping wall extending from the bottom 210. In FIG. 3a, such a point is also indicated by the reference character L. 210 As shown by:

[0064] Notably, the portion of the bottom 210 defined by the outlet 202, in one embodiment, is disposed relatively close to the second wall 232. More specifically, in one embodiment, the outlet 202 is A primary distance La is disposed between the portion of the bottom 210 defined by the outlet 202 and the second wall 232; a secondary distance Lb is located between the portion of the bottom 210 constituted by the outlet 202 and a plane Pto (for example parallel to the second wall 232, which may be planar) having a fourth normal N4 and including the central axis O of the cylinder 122; The primary distance La is smaller than the secondary distance Lb (La <Lb)、 is placed in position.

[0065] The primary distance La and the secondary distance Lb are shown in FIG.

[0066] This location of the outlet 202 also helps to keep the third angle γ reasonably low, which improves vortex formation in the interior 123 of the cylinder 122 .

[0067] Along these lines, for example, the inlet channel of FIG. 3. FIGS. 3a, 3b, 4a, 4b, 9c and 9d are particularly suitable as the inlet channel of the cyclone of FIGS. 2a-2c, since there the second wall 232 is arranged to have a small coordinate value in the third direction Sy. In contrast, in FIG. 10, the second wall 232 has a large coordinate value in the third direction Sy. However, in the embodiment of FIG. 10, for example, an inlet channel having a shape of a mirror image of one of the inlet channels of FIGS. 3a, 3b, 4a, 4b, 9c and 9d may be preferred, since in FIG. 10 the second wall 232 should have a large coordinate value in the third direction Sy and the bottom 210 is preferably close to the second wall 232, as detailed above. Here, the mirror image refers to a planar symmetrical image with a symmetry plane perpendicular to the third direction Sy.

[0068] With respect to the operation of the nozzle 220, the gas that fluidizes the solid material at the inlet can be supplied continuously or the gas supply can be pulsed.

[0069] In general, the type of gas supplied to the nozzle 220 can be selected as required. This implies, for example, that a gas with a low oxygen content is used if the gaseous substance G separated by the cyclone subsequently serves as fuel. Examples include pyrolysis and gasification. However, in combustion processes, gases with a high oxygen content, such as air, can be used. Furthermore, compressed air is naturally available, especially in fluidized bed boilers, since it is used as combustion air.

[0070] Thus, in applications where the reactor 810 producing mixture M is a fluidized bed boiler furnace 110, the same air may be supplied to the furnace 110 as combustion air and to the nozzle 220 to fluidize the material in the inlet channel 200 of the cyclone 120.

[0071] According to this and with reference to FIG. 11, an embodiment of the thermal system includes a first supply channel 820 for supplying gas to a reactor 810 of the thermal system. The thermal system can be a circulating fluidized bed boiler. The reactor 810 can be a furnace 110. In this embodiment, the first supply channel 820 includes a first branch 825. The purpose of the branch 825 is to split the gas into two parts: a first part for the reactor 810 and a second part for the inlet channel 200. Therefore, the thermal system includes a first pipeline 830 for conveying the second part of the gas from the first branch 825 to the nozzle 220. As detailed above, the first supply channel 820 is for supplying the first part of the gas to the reactor 810. In an embodiment in which the thermal system is a fluidized bed boiler, the first supply channel 820 is configured to supply (a first portion of) combustion air to the furnace 110 of the fluidized bed boiler, and the (second) portion of the combustion air is configured to be supplied to the nozzle 220 via the first branch 825 and the first pipeline 830.

[0072] As detailed above, in applications where the reactor 810 produces a gaseous substance G that can be used as a fuel, the gas supplied to the nozzle 220 should not contain much oxygen. In such embodiments, a portion of the gaseous substance G may be recycled for use as a fluidizing gas supplied to the nozzle 220. Accordingly, and with reference to FIG. 12, an embodiment of the thermal system includes a second pipeline 840 configured to supply a portion of the gaseous substance G separated by the cyclone 120 to the nozzle 220.

[0073] Of course, even if the thermal system is a fluidized bed boiler and air is supplied to the furnace 110, a portion of the gaseous substance G separated by the cyclone 120 can be used to fluidize the material in the inlet channel according to the embodiment of Fig. 12. However, typically the embodiment of Fig. 12 requires a pump or fan to recycle a portion of the gaseous substance G separated by the cyclone 120 to the nozzle 220. By using combustion air in the nozzle 220 as well, no separate pump is required.

[0074] As mentioned above, in one embodiment, the first direction Sz is vertically downwards. Therefore, the present invention also relates to the use of a cyclone 120 as disclosed above and / or in the appended claims, such that the first direction Sz is downwards. Additionally, the present invention also relates to the use of a thermal system as disclosed above and / or in the appended claims, such that the first direction Sz is downwards.

Claims

1. 1. A cyclone for separating solid material from a mixture of solid and gaseous materials, the cyclone comprising: A cylindrical body having a central axis in a first direction; an inlet channel configured to allow the mixture to enter the cylinder; and Including, the cyclone is configured to cause the solid material to exit the cylinder in the first direction; an interior of the inlet channel tapers in the first direction toward a bottom of the inlet channel; The cyclone includes a nozzle disposed at a bottom of the inlet channel, the nozzle configured to supply gas to the inlet channel to enhance a flow of the solid material at the bottom of the inlet channel.

2. The inlet channel of the cyclone comprises: Walls defining an interior of the inlet channel, at least a first of the walls comprising: a first angle between a first normal to at least a portion of a surface of the first wall and the first direction is between 110 and 160 degrees; the first normal faces the interior; The cyclone of claim 1 , wherein the cyclone extends from a bottom of the inlet channel as follows:

3. the inlet channel extends and is configured to feed the mixture into the cylinder in at least a second direction perpendicular to the first direction, and a third direction perpendicular to the first direction and the second direction; the width of the bottom is at most 50% of the width of the interior of the inlet channel; the width is defined in the third direction; a bottom of the inlet channel having a second normal facing an interior of the inlet channel and including a portion having no component in the third direction; The cyclone of claim 1 , wherein the width of the base is the width of a portion of the base having the second normal.

4. the inlet channel extends and is configured to feed the mixture into the cylinder in at least a second direction perpendicular to the first direction, and a third direction perpendicular to the first direction and the second direction; a bottom of the inlet channel having a second normal facing an interior of the inlet channel and including a portion that does not include a component in a third direction; The cyclone of claim 1 , wherein the nozzle is provided at a portion of the base having the second normal.

5. the inlet channel having an inlet for receiving the mixture and an outlet opening into the interior of the cylinder; at least a portion of a bottom of the inlet channel is inclined such that material moving along the bottom toward the cylinder moves in a direction having a positive component in the first direction; Preferably, a bottom of the inlet channel includes a portion having a third normal facing an interior of the inlet channel; the third normal has a first component in the first direction and a second component in the second direction; The cyclone of claim 1 , wherein a vector defined by the first component and the second component forms a second angle between 135 and 178 degrees.

6. 2. The cyclone of claim 1, wherein the nozzle is configured to supply gas to the inlet channel such that the supply of gas promotes a flow of material on a bottom of the inlet channel toward an interior of a cylindrical body of the cyclone.

7. The cyclone of claim 2 including an auxiliary nozzle disposed in at least a portion of the first wall having the first normal.

8. the inlet channel extends in a second direction and is configured to supply the mixture to the cylinder in at least the second direction, the second direction being perpendicular to the first direction; 2. The cyclone of claim 1, wherein the inlet channel has an outlet that opens into the interior of the cylinder, the outlet being disposed at a position where the second direction forms a third angle of at most 45° with a tangent direction of the cylinder, the tangent direction being defined at a location of the outlet.

9. walls defining an interior of the inlet channel, at least a second of the walls being attached to the cylinder; a portion of the second wall attached to the cylinder having a fourth normal; the cylinder defines a tangent plane at which the second wall is attached to the cylinder; the tangent plane has the fourth normal; Preferably, further comprising:

2. The cyclone of claim 1, wherein the inlet channel includes an outlet that opens into the interior of the cylinder, the outlet including a portion of the bottom, and the outlet is positioned at a position where a distance between the portion of the bottom defined by the outlet and the tangent plane is smaller than a distance between the portion of the bottom defined by the outlet and a plane that is parallel to the tangent plane and includes a central axis of the cylinder.

10. the inlet channel extends and is configured to supply the mixture to the cylinder in a second direction perpendicular to the first direction, and a third direction is perpendicular to the first direction and the second direction; The cyclone of claim 3 , wherein a bottom of the inlet channel is substantially centered in the inlet channel in the third direction.

11. the bottom of the inlet channel includes a heat transfer tube covered with mortar; Preferably, The cyclone of claim 1 , wherein the wall at least a portion of which has the first normal comprises a heat transfer tube covered with mortar.

12. A cyclone according to any one of claims 1 to 11; a reactor configured to produce the mixture of the solid material and the gaseous material; A thermal system comprising: The reactor comprises one of a furnace of a circulating fluidized bed boiler, a pyrolysis reactor, a gasification reactor, and a furnace of a bubbling fluidized bed boiler; The thermal system is configured to direct the mixture to the inlet channel of the cyclone.

13. a first supply channel for supplying a gas to a reactor of the thermal system, the first supply channel including a first branch; a first pipeline for conveying gas from the first branch to the nozzle; Including, Preferably, The reactor is a furnace of a circulating fluidized bed boiler; the first supply channel is configured to supply combustion air to the furnace; The thermal system of claim 12 , configured such that a portion of the combustion air is supplied to the nozzle via the first branch and the first pipeline.

14. The thermal system of claim 12 including a second pipeline configured to supply a portion of the gaseous material separated by the cyclone to the nozzle.

15. 12. Use of a cyclone according to any one of claims 1 to 11, wherein the cyclone is adapted such that the first direction is downwards.

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