static mixer having a pair of paddles for generating a vortex of flow toward a flow passageway

The present invention relates to report the "static mixer having a pair of paddles for generating a vortex of flow toward a flow passageway". The present invention relates to a static mixer having at least one pair of paddles for generating a vortex flow in the direction of a flow passage, according to the preamble of claim 1. this pair of paddles is a static mixing element inductor vortex. Such pair of paddle, or a plurality of pairs of vanes that are arranged side by side in the cross section of a passage, in particular a rectangular passage, forms a vortex-inducing static mixer. Normally, the pairs of blades are arranged along side one another in a "row"; they may, however, also be arranged along side one another and a above the other in a manner similar to a grid, in two or more "rows". A secondary fluid may, for example, be mixed with a primary fluid using the static mixing element inductor vortex. In this junction, the primary fluid may be a gas fired containing nitrogen oxides in which should be performed via a denitrification catalyst in a unit for reducing oxide (DeNOX), with the secondary fluid being measured as an additive in the form of ammonia or a mixture of ammonia/air. There may be provided a mixture of secondary fluid in the fluid primary homogenization required with slight loss of pressure using an apparatus known through the DE-a195 39,923 (31, a static mixer to a flow passageway. A homogenization can also be carried out only in the form of balance of Tempe - and/or ratura concentration with the static mixing element inductor vortex. In the known apparatuses, at least two paddles of vortex generating area are arranged in a passage traversed by the fluid such that the generation of a slipstream is forced in the direction of flow pass - Vetch, the main flow direction. The edges of the vanes in front of the side of attack are attached to a tube disposed perpendicular to the main direction of flow is parallel to a height (or shorter side) of the passage. This tube connects a fastening wall underbridge bottom wall overpass. The meter additive may be integrated into the tube. The second fluid fed into tube can be distributed in the primary fluid by a plurality of nozzles. The two paddles are offset with respect to each other and are secured to the fastening tube V shaped starting of leading edges, the paddles are bend in opposite directions so that they have a concave surface on the side of attack. The cross-sections of the paddles along the direction the main stream have an extension Iongitudinal variable and a variable alignment. In consequence of the special, the slipstream is created in the flow passageway, which performs a mixture over the entire total height of passage in the form of a primary vortex. It has been shown that a solution according to which the vanes are formed of thin-walled foils is not technically feasible, particularly for large dimensions mixers, ranging from a few meters, as are the common units for oxide reduction, waste incineration facilities, or the like, as is shown in DE 195 39,923 c1. This is due to a number of reasons: on the one hand, such paddles are too easily deformable, such that its construction according to the dimensions specified is almost impossible. Shipping and, in particular, assembly of such a mixer in a large flow conduit, for example, in flue gas conduit, which usually occurs at a place of construction under harsh conditions, requires, consequently, costly precautions. In addition, it has been shown in calculations of material strength, that blades, which in operation are subjected to solids finely granulated in suspension with high speed and large turbulence, tend to vibrate when light-like type of structure is used. Such vibration can lead to serious damage and, in consequence, should be avoided under any circumstances. To avoid these problems associated with the background art, the paddles, according to prior art, shall be made of foils of brick wall, which means foils with wall thicknesses of a few millimeters. Similar wall thickness foil causes numerous problems of manufacture, because such foil thick wall dimensions and geometry required is almost impractical mechanically, in particular lamination. A further disadvantage is to be considered the high consumption of material for the blades with foils made of thick wall, in particular if the length of the vanes is in the range of one meter or more. This consumption of material leads, on the one hand, to high material costs. On the other hand, the high consumption of material leads to a static mixer large weight, since the mixer is mounted within large flue gas conduits. Such conduits are usually flue gas foils in thin-walled and, in consequence, walls made of such thin-walled foils have a limited function. For mounting a mixer so heavy, flue gas conduits should be reinforced by additional complicated supporting structures. An additional possibility, although insufficient alone, adding rigidity to the vanes according to the prior art is also shown in DE 195 39,923 c1. In this advantageous embodiment, a joining plate attached perpendicular to the tube connects the two surfaces of the pair of paddles. The joining plate serves both for aerodynamic stabilization and for mechanical stabilization. However, this rigidity added is not appropriate to the paddles for flue gas conduits of large cross-section, because the free side edges of the paddles located opposite plate joining cannot be stiffened by this measure and, consequently, the paddle undesirable vibrations persist in ratio of vortices induced by the flow of flue gas, as described next. A plurality of pairs of vanes induces a corresponding number of primary vortices that enable an overall an additive on the cross section of the passage. In this junction, the respective senses of rotation of the primary vortices are critical. Adjacent vortices that rotate in the same sense join to form a rotation that extends over the active regions of the pairs of vanes, inducing these vortices. If the vortices have opposite directions, results better mixing isolated active regions; but, at the cost of the total mixture. In this case, may be generated bond mixtures between the adjacent vortices via additional guide members (as of-to-195 39,923), for improving the total mixture. In addition to primary vortices, secondary vortices are also formed, that is, behind the tube fixing and on free limbs blade pitch adjustment area. The secondary vortices may, admittedly, contribute to in situ mixing, but cause pressure losses and undesirable vibration effects. It would be advantageous if, at least in part, the occurrence of secondary vortices could be avoided. The object of the invention is to provide a static mixer vortex-inducing improved relative to pressure losses and vibration effects. This object is satisfied by the mixer of claim 1. The static mixer includes at least one pair of paddles for generating a vortex of flow toward a flow passageway. The edges of the vanes in front of the attack side are perpendicular to the flow passageway and parallel to a minor side of passageway which, below, is referred to as briefly of the height. The surfaces in the flow accompanying the flow continuity are bend concavely and in opposite directions. Each paddle is formed as a body designed aerodynamically including an end wall, a sidewall and a concave sidewall. The end wall has a convex shape or the shape of a on-attack. The cross sections of the paddles perpendicular side walls have, in particular, similar to the cross section of airplane wings. The dependent claims relate with 2 10 - lidades advantageous fashion the mixer, according to the invention. The invention will be explained in the following, taking as reference the drawings. Them, are shown: in Figure 1, a mixer according to the invention; in Figure 2, a pair of paddles this mixer in a somewhat simplified representation; in Figure 3 a clear representation of Figure 2 pair of vanes; and Figure 4 a cross section through a paddle. A mixer 1, according to the invention, as is shown taking as reference of Figure 1 4, includes at least one pair of paddles as a mixing element 2, with which a swirl flow 300, whose axis is faced with flow direction passage 3, is generated in a flow passageway 3 into a passage 10. A top side and an underside 10b 10 passage 10 define the height of the passage 10. the pair of paddles 2 includes a first paddle and a second paddle 2b 2. The edges of the vanes 2, 2b in front of the attack side are perpendicular to the flow passage 3 and parallel to the height of passage 10. The paddles 2 and 2b have walls or surfaces in the flow paddle 22 that follow the edges of front lengthwise flow and which are of a concave form and bend in opposite directions. The axis of the passage 10 defines the principal direction of flow (Figure 3) 30 flow passageway 3 wherein the whirlwind 300 is faced. According to the invention, each paddle 2, 2b is made as a body designed aerodynamically including an end wall 20, a convex sidewall 21 and the sidewall 22 concave. The paddle cross-sections transverse to the side walls 20, 21, 22 have a variable alignment extension and a Iongitudinal. They, particularly, have a similar shape to the cross sections through airplane wings. The alignment of the cross sections of the vane at an angle varies between 13 at an angle, as is shown in Figure 3. in this bonding, is advantageously less than 13. The convex end wall 20 is an elongate cylinder 20' or a tube 23 in the embodiment shown (Figure 4). Plates 26 (Figure 1) bonding produce an enhanced mechanical stability of the pair of paddles 2. end wall 20 has a convex shape in the embodiment shown; however, it may also be molded so as to form a special attack on-board in which powder particles cannot deposit, or may deposit only in a very limited degree. The paddles 2, 2b the mixing element 2 in the form of form bodies light weight structures; they are, in particular, hollow bodies. The walls wool - terais paddles 2, 2b are made, advantageously, of fine metal sheets, whose thickness is, for example, 1 millimeter, but may also be smaller, for example, 0.5 millimeter. Between the insides of the side walls 2, 2b are arranged elements splice stabilization, for example, strips of corrugated metal sheet 24 (see Figure 4), - espumo bodies (not shown) alone, or holders. In Figure 1, supports are shown as dashed lines 27. The paddles 2, 2b made as light weight structures can be manufactured such that, with a paddle height of one meter (or also greater), they are devoid of natural vibrations whose frequencies are within the range of 1 10 Hz. Natural vibrations located beyond this range are not excited by the passage 3; in particular, are not excited so-called hinge oscillations ("oscillating hinge" is an oscillation flow induced comparable to movement of a floating hinge wind). Thanks to the streamlined shape of the paddles, during flow inlet, the flow passage 3 enters the region of the static mixer elements in which the cross sections of flow between the paddles reduzemse continuously. In this junction, an increased momentum of the flow corresponds to a pressure drop. The cross sections of flow subsequently expand in the form of a diffuser. In this junction, the mayor - are can increase again without any substantial dissipation of kinetic energy. The reduced dissipation means that are only weakly secondary vortices formed, by which, for example, are not excited oscillations of hinge. The paddles 2, 2b are stiffened by light weight structures such that a excitement of oscillations is also, or totally absent because of mechanical properties modified, or at least transferred toward higher frequencies of oscillations and, by consequence, not critical. Patent cited-to-195 39,923, the use of thin-walled bodies, in particular those of sheet metal or plastic, is cited as a possible structure of the mixing elements. This embodiment is unsuitable for the construction of large mixers (a there - vature passage 1 amu 2 meters up) such as are often used in units for reducing oxide in function of requirements in strength and stability. This problem, according to the invention, is eliminated by the elements of the mixer 2 of the mixer 1. are not necessary stiffening structures spaced apart, for example, ribs, that, such unfavorable or influence the flow area along the surfaces of the paddles or effectuate deposits of dust and, in consequence, detract from the action of the mixer 1. May be performed a measure of additive in a known manner, via a grid disposed forward dosage of elements of the mixer 2 at passage 10. However, result in cost savings raised when measuring additive is integrated with the mixer elements 2, as is already provided in DE-a195 39,923. In contrast with this known way additive measurement, in which nozzles are arranged directly at the base of the paddles, has proved to be more advantageous provide discharge openings with the respective feeding the additives which direction of feed is faced toward or transversely to the direction of flow. Such measured not only have as a consequence a better mixing effect, but also the feeding is less sensitive to a non-uniform flow. In consequence, the apertures 42 are provides - in end wall 20 U side, in the vicinity of the end wall 20, as discharge openings meter integrated additive. The apertures 42 are nozzles, holes or laser-cut holes that can, for example, be round, rectangular, or slits. The additive to be measured is secondary flow (Figure 1) 4 that is to be mixed into the primary fluid flow passageway formed through each of the openings 42 3. defines a direction of feed of the secondary fluid 40 4 that determines a discharge angle of the direction of main stream 30. This discharge angle of the has a positive value in the range between 60 and 170, preferably between 120 and 150° to -. Computational Fluid Dynamics studies (computational Fluidodinâmica) with calculations at models produced a optimum value of 142.5 - 0. Meter integrated additive may also include openings for the secondary fluid 4 which are arranged in the side walls 21 and 22. The apertures 42 meter additive are periodic and at levels that have been made optimum form theoretical or empirically based on calculations of models or experimental. They are, for example, arranged in pairs and in specular symmetry relative to the axis of slipstream 300. Normally, however, all, or most, of the apertures 42 are located on different levels that may have different lengths. The apertures 42 may be connected to a supply conduit for the additive, or the additive is fed directly into the body through the section of paddle. In a particularly advantageous embodiment, the side walls 21, 22 of the pair of vanes 2 are connected by a joining plate (without representation of design), as is known from DE-to-195 39,923, that is perpendicular to the tube. If the joining plate is triangular shape with straight sides, edges protrude beyond the concave sidewalls 22. a improved mixing effect is achieved with such edges protruding from the plate joining, without an increase in pressure loss. The walls of vanes 21, 22 are made at least partially of metal, ceramic material and/or plastic. A mixer 2 metal can be coated with a ceramic material or plastic. The use of the mixer according to the invention is particularly advantageous when the height (minor side) of the passage 10 is greater than 0.5 meter, preferably greater than 1 meter. 2 mixer elements (pair of paddles) advantageously extend beyond the height of the passage 10, when then are arranged in a row. In this case, the number of mixer 2 is, in consequence, substantially the same as the quotient of the width of passage with the passage height. Typical values for this number range from 2 8. depending on the number of mixer 2, results - a large number of more or less efficient - various arrangements: for example, all of the elements of mixer 2 rotating alternately or in the same direction. It is possible, thus, make the arrangement of the elements of optimal mixer 2 for an object which results relative to a distribution uneven temperature or concentrations, given the status starting given situation. The pairs of vanes 2 also can be arranged in two or more "rows", instead of a "row", with the "rows" normally not being separated from one another by walls.