EP3794295B1 - Drehrohrapparat - Google Patents

Drehrohrapparat Download PDF

Info

Publication number
EP3794295B1
EP3794295B1 EP19727590.2A EP19727590A EP3794295B1 EP 3794295 B1 EP3794295 B1 EP 3794295B1 EP 19727590 A EP19727590 A EP 19727590A EP 3794295 B1 EP3794295 B1 EP 3794295B1
Authority
EP
European Patent Office
Prior art keywords
rotary tube
tube apparatus
welding
hollow tubes
sections
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP19727590.2A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP3794295A1 (de
EP3794295C0 (de
Inventor
Niclas SCHULTHEIS
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Grenzebach BSH GmbH
Original Assignee
Grenzebach BSH GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Grenzebach BSH GmbH filed Critical Grenzebach BSH GmbH
Publication of EP3794295A1 publication Critical patent/EP3794295A1/de
Application granted granted Critical
Publication of EP3794295B1 publication Critical patent/EP3794295B1/de
Publication of EP3794295C0 publication Critical patent/EP3794295C0/de
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D15/00—Handling or treating discharged material; Supports or receiving chambers therefor
    • F27D15/02—Cooling
    • F27D15/0206—Cooling with means to convey the charge
    • F27D15/028—Cooling with means to convey the charge comprising a rotary drum
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B7/00—Rotary-drum furnaces, i.e. horizontal or slightly inclined
    • F27B7/20—Details, accessories, or equipment peculiar to rotary-drum furnaces
    • F27B7/38—Arrangements of cooling devices
    • F27B7/40—Planetary coolers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D15/00—Handling or treating discharged material; Supports or receiving chambers therefor
    • F27D15/02—Cooling
    • F27D15/0206—Cooling with means to convey the charge
    • F27D15/0273—Cooling with means to convey the charge on a rotary hearth
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D9/00—Cooling of furnaces or of charges therein
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D9/00—Cooling of furnaces or of charges therein
    • F27D2009/0002—Cooling of furnaces
    • F27D2009/0051—Cooling of furnaces comprising use of studs to transfer heat or retain the liner
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D9/00—Cooling of furnaces or of charges therein
    • F27D2009/007—Cooling of charges therein
    • F27D2009/0072—Cooling of charges therein the cooling medium being a gas
    • F27D2009/0078—Cooling of charges therein the cooling medium being a gas in indirect contact with the charge
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D11/00—Heat-exchange apparatus employing moving conduits
    • F28D11/02—Heat-exchange apparatus employing moving conduits the movement being rotary, e.g. performed by a drum or roller
    • F28D11/04—Heat-exchange apparatus employing moving conduits the movement being rotary, e.g. performed by a drum or roller performed by a tube or a bundle of tubes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/40—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only inside the tubular element

Definitions

  • the invention relates to a rotary tube apparatus, in particular a sectional cooler for cooling a free-flowing solid, with structures attached to its walls to increase heat conduction.
  • a rotary tube apparatus is used to cool or heat a free-flowing material, in particular bulk material.
  • a rotary tube apparatus, particularly in its configuration as a sectional cooler, is used for continuous processes in chemical engineering.
  • coolers are required to cool very hot products such as burnt pigments, slag, metal oxides and hydroxides, cement clinker, sponge iron, scale, activated carbon, catalysts, coke, smelting works residues, etc. Further processing is often not possible without cooling the very hot products. In many cases, as part of the technologically necessary cooling, the thermal energy contained in the solid should be at least partially recovered.
  • rotary tube coolers operated indirectly with air or water are used for this task.
  • "Indirectly” means that the cooling medium, for example water or air, does not come into direct contact with the hot product to be cooled, but heat is exchanged from the hot product to the cooling medium via an apparatus wall separating the media.
  • a rotary tube is sprayed with water from the outside; or the drum is run through a water bath, as in U.S. 4,557,804 A described, whereby the surface of the rotating drum is wetted with water and cools the apparatus wall, while in turn the hot product located in the drum is cooled by heat dissipation to the cooled apparatus wall.
  • a rotary tube cooler with a rotary tube which rotates within a stationary, brick-lined enclosure and in which the cooling medium, for example air or water, flows in the cavity formed between the rotary tube and the lining.
  • the cooling medium for example air or water
  • U.S. 2,283,129 A and EP 2 889 569 A1 disclose rotary tube apparatus. Out of DE 160 351 C and U.S. 4,637,034 A stationary arrangements for improving the heat transfer are known.
  • each chamber thus fills out a sector of a circle or cross-section of a circle.
  • cooling water is passed through the cavities formed in the drum housing between the sections.
  • the cooling water is supplied and removed via a sealed swivel joint on the product discharge side of the drum and pipe connections to and from the individual double pipes.
  • sectional coolers have a special design that leads to high material and labor costs in production, especially due to the extensive welding work required.
  • the drum housing itself necessarily has a high weight, because the drum and the walls of the chambers must be made thick-walled for reasons of strength. Although both lead to a high overall weight of the apparatus, they permit particularly effective heat dissipation.
  • Sectional coolers essentially consist of a rotating rotor, which is usually driven by a chain. At the ends of the rotor are rigid housings for product infeed and outfeed. Depending on the size of the cooler, the rotor is either mounted on the ends of its own axis (axle cooler) or has a rotary tube typical race bearing. Inside, the rotor consists of several sectional chambers, which are arranged in the shape of a pie around a central hollow shaft. This arrangement is completely surrounded by the outer jacket. Conveying elements are located in the sectional chambers. Depending on the requirements, these can be shovels, chains or the like.
  • sectional coolers are built with diameters between 0.8 and 4 m and lengths of 3 to 30 m.
  • Sectional coolers work with indirect water cooling.
  • the cooling water passes through an inner central hollow shaft between the individual sections, flows around them and exits again through an outer central hollow shaft.
  • the product to be cooled usually falls directly into the product drop housing and is transported to the other end of the cooler by the rotary movement and the conveying elements.
  • the rotation ensures that the product is constantly mixed in the sections and thus good heat transfer is achieved.
  • the product can be conveyed in parallel or countercurrent to the cooling medium.
  • Sectional coolers can be used to cool almost all free-flowing bulk materials. They are often found behind rotary kilns in calcination processes or the like. Their main goal is usually to cool the products down enough so that they can be handled with other equipment (conveyors, mills, etc.). However, the cooling itself is often an important part of the manufacturing process. Typical products are e.g. B. petroleum coke, zinc blende roasted goods, soda, pigments and many more. The inlet temperatures of the products can be up to 1400 °C.
  • the invention relates to any rotary tube apparatus that is used to cool or heat a free-flowing material.
  • a rotary tube cooler and its cooling function as an example of such a rotary tube apparatus; nevertheless, the invention is intended to be used for any pourable material introduced into such a rotary tube cooler.
  • the hollow tubes are preferably arranged in rows, which extend in the longitudinal direction of the rotary tube apparatus.
  • two adjacent rows of hollow tubes each have a staggered arrangement of the hollow tubes.
  • the hollow tubes can be attached to the walls of sections by screwing, gluing or riveting, for example.
  • Welding methods are also suitable, for example, in particular submerged arc welding, gas metal arc welding, friction welding or stud welding.
  • a method that is particularly adapted to hollow pipes and is therefore particularly suitable is sleeve welding.
  • the hollow tubes have a length of less than 10 cm, in particular less than 5 cm. Most preferably they have a length of 3.6 cm.
  • the hollow tubes advantageously have a diameter of less than 5 cm, in particular 3.0 cm.
  • the hollow tubes have a wall thickness of 1 cm or less, in particular 0.5 cm.
  • the rotary tube cooler has a plurality of sections having a higher density of hollow tubes on the radial walls and on the circular arc wall exhibit than in the corner areas between the radial walls and between the radial walls on the one hand and the arc wall on the other hand.
  • the sections each have about 500 ribs or 500 hollow tubes per meter of length of the rotary tube cooler.
  • the invention also relates to a method for operating a rotary tube apparatus, in particular a rotary tube cooler, as described above.
  • the method is characterized in that the solid moves in a turbulent flow around the hollow tubes.
  • a large number of criteria are taken into account when optimizing a rotary tube cooler.
  • the best possible combination of material, joining process and geometry is determined.
  • the optimization of the heat transfer of the rotary tube cooler, in particular of the sectional cooler is mainly improved by the introduction and optimization of the cooling fins.
  • the substrate to be cooled is introduced into a rotary tube cooler, for example a sectional cooler, at a high temperature, for example at up to 950° C.
  • the temperatures of the sections are lowered by the constant cooling of the sections by a cooling fluid, for example water.
  • a cooling fluid for example water.
  • cooling fins in the sections can reach a temperature of 550 °C, for example, at the point at which the product enters.
  • the mechanical stresses on the ribs are low. They are limited to stress caused by contact with the product.
  • the ribs do not have a supporting or strength-enhancing role within the sectional cooler. Therefore, materials can also be considered whose application limit is below the mentioned 550 °C.
  • the main stress lies in the area of wear resistance due to the substrate to be cooled or heated, for example powdered zinc oxide. Depending on the composition of the atmosphere inside the sectional cooler, high-temperature corrosion processes can also take place.
  • the selection of the material to be used is made based on a number of criteria. Since the main stress on the cooling fins is the wear caused by the zinc oxide, it is important to keep this as low as possible.
  • the types of wear that occur are sliding wear and impact wear. High resistance to both types, composed of the mechanisms of abrasion and surface distress, can be achieved through a combination of high hardness and ductility. The abrasion mechanism can be counteracted by making the material very hard.
  • abrasion wear is divided into three zones. In the zone with a ratio of less than 0.6, the greatest wear occurs due to the low hardness of the component. In an area with a hardness ratio of the two components between 0.6 and 1.2, there is a transition from the high wear level to the low wear level. From a value of 1.2, wear from abrasion is minimized, since the wear body cannot penetrate the component due to its lower hardness.
  • Table 1 category short name material number Thermal conductivity [W/(mK)] Expansion coefficient [*10 ⁇ -6K ⁇ -1] Specific heat capacity [J/(kgK)] Modulus of elasticity [N/mm 2 ] Density [kg/m 3 ] Hardness Brinell [HBW] aluminum alloy AlMg1SiCu 3.3211 170 23.0 895 70,000 2,700 88 magnesium alloy AM50A (EN MCMgAl5Mn) EN-MC21220 65 14.0 1020 45,000 1,770 58 pure nickel nickel 201 2.4068 79 1, 8 456 205,000 8,900 95 Structural steel S355JR 1.0045 54 0.0 461 210,000 7,850 170 tempered steel 25CrMo4 1.7218 49 0.4 435 210,000 7,750 216 Structural steel S235 1.0038 54 0.0 461 210,000 7,850 123 carbon steel SAE AISI 1008 1008 65 13.1 470 190,000 7,900 97 High-temperature steel P235GH 1.0345 57
  • the heat-treated steel 25CrMo4 is the only material that is in the low wear zone. The magnesium alloy, the pure nickel and the carbon steel are in the area of maximum wear due to abrasion. All other materials are in the area of the transition ( 2 ).
  • materials that are in the upper right area of the diagram are preferable for use in a rotary tube cooler due to their combination of hardness and elongation at break.
  • Materials found in the lower right such as nickel, have good wear resistance to surface distress, but their low hardness makes them susceptible to abrasion.
  • the two alloys of aluminum and magnesium do not show particularly good resistance for either mechanism.
  • a weighting factor must be included, which is figure 3 is not taken into account. For example, the ratio of abrasion to surface distress is given by 2 3 to 1 3 fixed.
  • the thermal conductivity of the individual materials is primarily taken into account. Regardless of the geometry, increased heat flows can be achieved by using particularly suitable materials with higher thermal conductivity.
  • the number of materials that can be used may be limited depending on the joining process.
  • the coefficient of thermal expansion must be taken into account. If the sections are made of mild steel, which has a coefficient of about 12 ⁇ 10 -6 K -1 , if the cooling fins are made of other materials, stresses can arise. The sections and cooling fins are at room temperature during the joining process. If the cooler is now put into operation, the temperature rises and the components expand. Materials with different coefficients of thermal expansion therefore expand to different extents.
  • the aluminum alloy has the greatest thermal conductivity, but also a large difference in the thermal expansion coefficient of structural steel. Together with the magnesium alloy, which has a significantly lower thermal conductivity compared to the aluminum alloy, the greatest stresses are to be expected in the area of the joining zone. All other materials are in a similar range of thermal expansion coefficients and thermal conductivity, with the stainless ferritic steel X6CrMoS17 having the lowest thermal conductivity.
  • heat flow shown as a function of thermal conductivity A course is shown that is similar to that of a square root function. At low values of thermal conductivity increases the heat flow increases sharply. With increasing thermal conductivities, the heat flow continues to increase, but the slope of the curve decreases sharply. For this reason, the heat flow of X6CrMoS17 is about 20% lower than that of S235JR, although the thermal conductivity is over 50% lower. The thermal conductivity of the aluminum alloy exceeds that of mild steel by more than 200%. The gain in heat flow, on the other hand, is only 20%. The course therefore approaches a maximum heat flow.
  • figure 5 shows the transferred heat flow as a function of the thermal conductivity.
  • Another evaluation criterion is the thermal conductivity in relation to the explained thermal fatigue. Although the number of operating cycles of a sectional cooler is low, since they are almost exclusively taken out of service for maintenance and repair, thermal fatigue of the cooling fins can still occur if the temperature conductivity is too low. Therefore, higher thermal conductivity of the materials, as well as the geometries, are to be preferred in order to avoid cracks in the components and signs of fatigue.
  • the thermal conductivity of the materials in relation to the thermal conductivity shows the thermal conductivity of the materials in relation to the thermal conductivity.
  • the aluminum alloy again achieves the best result due to the high thermal conductivity as well as the thermal conductivity. Since the thermal conductivity is composed of the thermal conductivity, the density and the specific heat capacity, it becomes clear why the aluminum alloy with the low density and the high thermal conductivity has a high thermal conductivity.
  • the magnesium alloy also has a high thermal conductivity. In terms of thermal conductivity, the alloy X6CrMoS17 has the worst properties.
  • the other materials have approximately the same thermal conductivities, with the known differences in thermal conductivities.
  • the transferred heat flow is also included in the evaluation with the same weighting factor, since it has been shown that the thermal conductivity is crucial for the heat flow, but does not have a linear course. Accordingly, the determined heat flow serves as an additional factor to compensate for this non-linearity.
  • the criteria associated with wear and tear or fatigue of the materials also have a major influence.
  • the evaluation is carried out by assigning the value one to the highest value of an evaluation criterion.
  • the value zero forms the lower limit in each case.
  • a linear progression is formed between the upper and lower value, so that the remaining values lie between the two limits.
  • the determined values are then multiplied by the respective weighting factor. This is carried out for the various evaluation criteria and finally the individual results are summed up. The best possible evaluation of the total is therefore one.
  • the heat-treatable steel has the considerable disadvantage that in the case of a weld, it has to be stress-relieved for several hours at temperatures between 680 °C and 720 °C and then slowly cooled down in order to reduce stresses within the heat-affected zone by welding. In the case of the large components of a sectional cooler, this also means a great deal of technical effort in addition to the time.
  • the easy-to-weld structural steel S355JR does not require such a time-consuming, but also costly post-treatment.
  • the heat-treated steel 25CrMo4 is therefore to be preferred for all joining processes, except for welding, where the advantages of mild steel in terms of easier handling predominate.
  • a major advantage of bonding is that an equivalent result can be achieved with all metals with good pre-treatment. Accordingly, different material combinations are possible. However, depending on the type of adhesive used, there are other factors to consider.
  • Structural adhesives can absorb stresses of up to 30 MPa. Compared to the other joining methods, this is many times lower. However, in order to be able to withstand these stresses, very complex pre-treatment of the workpieces is necessary, since this is the only way to ensure good wetting of the surfaces, which is decisive for the quality of the bond. Since an even and thin layer thickness of the adhesive is also crucial, both sections and cooling fins must meet high tolerance requirements. Despite the low thermal conductivity of the adhesive, the heat flow is only imperceptibly changed due to the small layer thickness.
  • Screw connections which can also be used to connect different materials to one another, are even more advantageous than adhesive connections. Since the connections are not material-to-material but friction-locked, high dimensional accuracy must also be maintained in order to produce full-surface contact between the rib and the section so that the heat is transferred via thermal conduction. Voids between section and rib result in free convection between the two components. This would significantly reduce the transferred heat flow.
  • screw connections can withstand significantly higher stresses by adapting the components used, such as screws and nuts.
  • a large number of holes must be drilled into the sections through which the screws are guided. This reduces the rigidity of the sections.
  • this area must be sealed. This requires the use of additional components.
  • a section 1 ( 7 ) of a sectional cooler has a rib 2 with a rectangular shape (rectangular rib) and is connected to a wall 5 of the section 1 via a screw 3 and a nut 4 .
  • the rib 2 forms a bearing surface for the screw head of the screw 3.
  • Rivet connections can also be used as an alternative to using screw connections
  • the press connection method requires the use of ribs which are pushed through the wall of the section at least in some areas.
  • the wall of the section and the respective rib can also be glued or welded.
  • Another method of making a connection between the ribs and the wall is joining by welding, divided into two categories. Both submerged arc welding and metal inert gas welding are used, as well as friction welding and stud welding.
  • Submerged arc welding is not suitable for all welding positions because the powder lies loosely on the welding zone. This means that only welding positions with a low inclination can be realized.
  • Each section of a sectional cooler consists of two parts joined together. These are welded together after the turning bars and conveyor blades have been installed.
  • the welding torches for both automated and manual MSG welding have significantly smaller dimensions.
  • the preparations to weld the ribs to the sections are less than the preparations required when gluing, screwing or riveting. Inaccuracies can be compensated for by introducing additional filler metal.
  • the ribs With regard to the heat flow, the ribs only have to be provided with chamfers in order to be able to guarantee full-surface contact. Within the weld seam, the material's thermal conductivity is almost identical to that of the starting material. Thus, very good results can be achieved in terms of the heat flow transferred between the two components by welding with full-surface contact between the rib and the section.
  • Friction welding is opposed to stud welding. Friction welding is characterized by very good quality in the area of the welding zone. The strength is higher than that of the base material. The thermal load and the associated distortion and residual stresses are also lower than with a fusion welding process.
  • Stud welding is characterized by very short welding times. These are significantly below those of friction welding. Due to the short welding times, the thermal load is lower than, for example, with MSG welding. The strength of the material connection is higher than that of the base material. The connection is also not affected by aging processes, as is the case with adhesive bonds.
  • the preparation of the welding zone is identical to that of MSG or submerged arc welding (submerged arc welding) and therefore also significantly less compared to the other processes considered.
  • cutting the long rod to the desired length is sufficient as preparation in the area of the fins.
  • the sections do not have to be provided with complex bores with minimum tolerances. Welding fillers are not required, only shielding from the atmosphere with a protective gas is necessary.
  • the small dimensions of the welding gun of a stud welder allow easy attachment of the ribs in all areas of the section.
  • the manual skill required is very low due to the easy handling of the welding gun.
  • the maximum weldable diameter of the cooling fins is limited to 30 mm.
  • the blowing effect must also be taken into account in order to achieve full-surface contact and thus the best possible heat transfer.
  • the outer diameter is limited to 30 mm.
  • Stud welding offers the best compromise due to the good mechanical properties of the joining zone in combination with the easy handling of the welding gun and the very short welding times. Stud welding should therefore be used for round geometries of the cooling fins.
  • the structural steel S355JR is to be preferred over the heat-treated steel 25CrMo4, as it is very easy to weld and does not require any post-treatment. Since S355JR structural steel is a low-alloy structural steel, an active gas is recommended as the shielding gas because it is cheaper than an inert gas.
  • a geometry of the cooling fins is also created which satisfies a number of criteria, in particular with regard to the heat flow.
  • the heat flow based on the contact surface between the cooling fin and the section, is used to determine the heat flow, based on 1 mm 2 .
  • This allows the efficiency of the different geometries to be estimated independently of the size of the rib or its contact area with the section. Since some ribs, such as the bladed ribs, occupy a significantly larger area of the section than their contact area, this is accounted for by a projected area, ie the area covered by the contour of the rib
  • the heat flow is also related to the projected area.
  • the weight of the ribs is also included in the evaluation.
  • the heat flow serves as a further criterion for the efficiency of the geometry under consideration. With a high quotient from heat flow and weight, better use of resources is achieved, material consumption and the associated material costs are reduced.
  • Table 4 shows the weighting of the various criteria.
  • the two heat flows related to the surfaces are the decisive criteria of the geometries. For this reason, the weighting factors together are 0.65.
  • Relating heat flow to fin weight gives an indication of the efficiency of the fin, but is not a definitive indication of the overall improvement in heat flow to the currently used cooling fin.
  • the criterion should not be neglected, but with a weighting factor of 0.2 it is factored less than the heat flows, based on the areas. With a weighting factor of 0.15, thermal conductivity is below the other factors. This is justified because the ratio of the heat flows at different times is primarily decisive for thermal fatigue.
  • Table 4 Weighting factors of the geometry evaluation criteria evaluation criterion weight factor heat flow per area 0.4 Heat flow per projected area 0.25 heat flow per kilogram 0.2 thermal conductivity 0.15 total 1
  • the different geometries are evaluated in a similar way to the material pre-selection.
  • the highest value of an evaluation criterion is given the value 1.
  • a linear gradation down to the value 0 is then formed and the remaining geometries are provided with the corresponding value.
  • the values are multiplied by the weighting factors and then summed up.
  • the maximum achievable sum is therefore 1.
  • Table 5 shows the evaluation of the geometry.
  • the tubular geometry of the cooling fin is explained below using a standardized tube as an example.
  • the dimensions are taken from DIN EN 10220, for example.
  • the evaluation is carried out identically to the evaluation given above.
  • the same evaluation criteria with the same weighting factors are used.
  • another evaluation criterion, the heat flow is added. Since each is a tube rib, this addition is possible without further adjustments.
  • the heat flow is weighted with a factor of 0.3. The maximum achievable sum thus increases to a value of 1.3.
  • Table 6 shows the evaluation of the optimization of diameter and wall thickness.
  • Geometry determines the most preferred length of the rib.
  • the degree of filling ⁇ is determined. This is made up of the residence time, the volume flow of the zinc oxide and the volume of the sections.
  • the degree of surface coverage can be determined based on the degree of filling.
  • the graphical determination of the area coverage of a preferably inclined or alternatively horizontally mounted sectional cooler 8 is in 10 shown in cross section. It shows that each area of the section is covered for a similar period of time. There is therefore no area in which the attachment of cooling fins would not have a positive effect. If you take a closer look at the distribution of the zinc oxide, you will notice that the product has different speeds in the different areas. In the 10 Areas labeled A, A' and A" are the zones where the zinc oxide is flowing at lower velocities, while in areas B, B' and B" it is moving at higher velocities.
  • the main purpose of the turning bars is to reduce the speed of the product in order to reduce the wear of the sections.
  • an increased number of cooling fins in the areas is preferred B, B' and B" of the sections, on the one hand to take advantage of the flow in terms of heat transfer, but also to reduce the speed of the product to the extent that wear is kept low.
  • cooling ribs are also attached in areas A, A' and A", since the heat transfer through the ribs is also significantly improved at the lower speeds of the product.
  • the calculated temperature profile can be used to determine the positions within the cooler for the heat transfer coefficients.
  • the preferred number of cooling fins to be introduced is also determined.
  • the geometry of rectangular strips, for example with the dimensions 9.9 m ⁇ 0.01 m ⁇ 0.03 m, and the tube ribs used are considered.
  • the maximum number of fins per section is limited to 917 per meter of cooler. With this number of fins, a heat flux twice that of the prior art is achieved.
  • the geometry of the ribs in a section 9 of a sectional cooler 8 according to the invention is as shown in 9 is shown.
  • figure 12 shows the top view of the tube ribs 10 in one of the zones of higher particle velocity. Due to the offset of the ribs 10 between the rows of ribs 11, 12, the fine-grained zinc oxide constantly flows against them. On the one hand, this reduces the speed of the zinc oxide, but on the other hand, the deflection of the grains creates a turbulent flow, which improves the convective heat transfer.
  • the inside 12 The arrow shown indicates the direction of flow. An example of what the flow around one of the ribs 10 might look like is in 13 shown. Immediately in front of the rib, the particles are deflected outwards. Several turbulences arise behind the rib, which are characteristic of turbulent flows. It also shows that particles with lower speed are directly behind the rib.
  • conveyor blades are also provided within the sections.
  • Table 10 Adjustment and comparison of the residence time of the particles according to the invention (New) versus the prior art (Old) Surname Old New Length of cooling chamber LK 9.9 7:18 m number of bladed walls n Ws 3 2 - pumping efficiency n 0.3 0.3 - Number of blades per wall ns 15 11 - Offset blades axial ss 0.22 0.18 m number of revolutions n 4.7 4.7 min -1
  • the selected joining process is characterized by very short welding times, so that the many ribs can be welded in the shortest possible time. These short welding times are associated with lower thermal loads than with other fusion welding processes. This is also reflected in the low distortion of the sections and low residual welding stresses in the heat-affected zone.
  • Another advantage is the easy handling of the welding gun, so that even less trained personnel can carry out the welding; however, the welding can also be automated by a welding robot. through the The small dimensions of the welding gun also ensure accessibility to the sections.
  • the larger the diameter the better the results.
  • the mechanical properties of the material exceed those of the base material in the area of the joining zone. In combination with the material selected for the ribs 10, this results in a high resistance to the predominant proportionate abrasion in the area in which the product hits the ribs 10.
  • the hardness of S355JR mild steel exceeds that of the section by almost 40%. Due to the low weight of the selected geometry, the additional costs due to the higher-quality structural steel are negligible.
  • the walls of the section 8 and the ribs have at least substantially equal values. Due to the same thermal expansion coefficients, there are no stresses caused by different degrees of expansion of the components in the case of temperature differences. The problem of thermal fatigue also does not apply due to the same thermal conductivity of the two materials, since no signs of fatigue of this type have occurred in previous coolers with turning strips made of S235JR.
  • both materials are construction steel or low-alloy steels, they can be welded very well. In addition, no post-treatment of the joining zone is necessary.
  • the fins 10 are easily made by cutting through tubes. Another advantage is that the selected steel is a very common steel.
  • the geometry of the rib convinces with a very good result even without optimization.
  • the values exceed those of the optimized rectangular rib. Optimization achieves even better results.
  • the geometry is characterized by a large heat exchange surface with a low weight.
  • ribs 10 should preferably be arranged in a staggered manner. This means that the original task of the turning bars, which was to reduce wear on the sections, is fulfilled despite the new geometry.
  • the round geometry paired with the offset arrangement of the fins, creates a more turbulent flow, which improves heat transfer.
  • the outside of the rib is constantly in contact with the product to be cooled, which also ensures high heat transfer.
  • cooling fins to be installed has yet to be determined.
  • the considered value of 500 cooling fins 10 per section 8, based on a meter length, is just an example.
  • a reduction in the weight of the cooler is accompanied by further advantages.
  • the torque required to set the cooler in rotation is lower.
  • its load drops, or a cheaper motor with less power can be installed. This reduces the energy requirement of the system.
  • the mechanical loads in the area of the pinion and the ring gear for the transmission of the motor drive to the outer wall of the rotary tube cooler are reduced.
  • the loads acting on the bearings are reduced.
  • the load or dimensioning of the foundations can also be lower or designed to be smaller.
  • the sectional coolers are used all over the world. However, the coolers are always manufactured at the same location. Thanks to their lower weight and smaller dimensions, the sectional coolers require less effort to handle during transport and installation of the cooler. The space costs of the sectional cooler, which are incurred when calculating a system, are also lower.
  • Each of the eight sections of this cooler is provided with 16 turning strips, for example. Their task is to reduce the speed of the particles in order to minimize wear on the sections. Since it has been shown that more thermal energy is also transferred through the turning strips, they also serve as cooling fins. With regard to the optimization of this property, the turning bars are examined.
  • the material is determined by considering seven different relevant properties.
  • the wear mechanisms that stress the ribs are abrasion, which can be reduced by high hardness of the material, and surface distress, which is reduced by ductility.
  • the differences in the thermal expansion coefficients are also included in the evaluation.
  • the thermal conductivity and the heat flow are also included in the evaluation.
  • the evaluation of the ten materials provides the result that the structural steel S355JR is best suited for use as the material for the cooling fins, taking into account the joining process selected afterwards. Due to a higher hardness compared to the S235JR alloy, abrasion wear is reduced. Due to the identical values of the heat conduction and the heat flow of the structural steel S355JR to the structural steel S235JR, there are no losses in the area of heat transfer. Since both materials also have the same coefficient of thermal expansion, there are no stresses in the contact area between the rib and the section due to temperature differences between the condition when the cooler is in operation and when it is not in operation.
  • MAG welding is used for elongated cooling fins.
  • the cooling fins are to be provided with two chamfers and to be connected to the sections by a double HV seam over the entire surface.
  • Stud welding is suitable for round geometries due to its very short welding times and very good mechanical properties of the joining zone.
  • no additives are necessary. Preparation is limited to cutting the ribs to the required length and the manual skill required to operate a stud welder is minimal.
  • the other decisive factor of the cooling fin, the geometry is also achieved by evaluating different criteria.
  • the heat flow related to the contact area, the heat flow related to the projected area, the heat flow related to the weight of the cooling fin, and the thermal conductivity of the geometry are considered. After evaluating the various geometries, a bar rib with a hole is chosen.
  • the consideration of the material flow shows that there are areas with higher and lower particle velocities. Due to the more turbulent flow and the additional task of reducing the particle speed, more ribs are to be installed in the higher speed areas than in the lower particle speed area. In addition, the ribs are to be arranged in a staggered manner. This ensures that material flows directly against each rib. Another positive effect of the selected geometry is that turbulence of the product occurs behind the rib, which further improves the heat transfer through a more turbulent flow. With the help of the heat transfer coefficients determined for the different positions under temperatures within the cooler, it can be determined that the ribs have an almost identical positive influence on the transferred heat flow along the cooler.
  • a list of the weight difference depending on the number of cooling fins used shows the possible potential of the optimized tube fins.
  • the economic optimum can be determined from the costs due to the increasing assembly effort in relation to the material saved, the weight and the resulting further possible savings with an increasing number of cooling fins. As a result, the corresponding economic and technical design of the cooler must be carried out.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Geometry (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
  • Arc Welding In General (AREA)
  • Arc Welding Control (AREA)
  • Pressure Welding/Diffusion-Bonding (AREA)
  • Furnace Details (AREA)
EP19727590.2A 2018-05-14 2019-05-10 Drehrohrapparat Active EP3794295B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102018003840 2018-05-14
PCT/EP2019/000140 WO2019219233A1 (de) 2018-05-14 2019-05-10 Drehrohrapparat

Publications (3)

Publication Number Publication Date
EP3794295A1 EP3794295A1 (de) 2021-03-24
EP3794295B1 true EP3794295B1 (de) 2023-07-26
EP3794295C0 EP3794295C0 (de) 2023-07-26

Family

ID=66677093

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19727590.2A Active EP3794295B1 (de) 2018-05-14 2019-05-10 Drehrohrapparat

Country Status (12)

Country Link
EP (1) EP3794295B1 (ja)
JP (1) JP7286901B2 (ja)
KR (1) KR20210008082A (ja)
AU (1) AU2019268508A1 (ja)
CA (1) CA3099902A1 (ja)
CL (1) CL2020002937A1 (ja)
ES (1) ES2957358T3 (ja)
MX (1) MX2020012246A (ja)
PE (1) PE20210532A1 (ja)
RU (1) RU2771058C1 (ja)
WO (1) WO2019219233A1 (ja)
ZA (1) ZA202007283B (ja)

Family Cites Families (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE160351C (de) * 1904-04-07 1905-05-10 Heiz- oder kuhlkörper
US1218873A (en) 1913-11-29 1917-03-13 William Lennon Trough or flume.
US1711297A (en) 1928-02-06 1929-04-30 Wiltse Appliance Co Pump mechanism
US2283129A (en) 1940-11-25 1942-05-12 Allis Chalmers Mfg Co Rotary clinker cooler
US2362539A (en) 1942-07-21 1944-11-14 Traylor Engineering And Mfg Co Rotary water-cooled tube cooler
US2348446A (en) 1943-08-09 1944-05-09 Allis Chalmers Mfg Co Rotary cooler
JPS4832639U (ja) * 1971-08-21 1973-04-20
BE792880A (fr) 1971-12-15 1973-03-30 Kloeckner Humboldt Deutz Ag Refroidisseur a satellites pour four tubulaire rotatif
ZA74222B (en) 1973-02-01 1975-01-29 Polysius Ag Planetary cooler
JPS50137307U (ja) * 1974-04-27 1975-11-12
GB1447349A (en) 1975-03-18 1976-08-25 Smidth & Co As F L Planetary coolers
GB1502351A (en) 1975-07-23 1978-03-01 Smidth & Co As F L Planetary cooler
US4131418A (en) 1977-05-23 1978-12-26 Fuller Company Tube coolers for rotary kilns
FI71837C (fi) 1982-11-26 1987-02-09 Partek Ab Nedloppskonstruktion foer kylare i roterugn.
US4637034A (en) * 1984-04-19 1987-01-13 Hylsa, S.A. Cooling panel for electric arc furnace
US4557804A (en) 1984-05-18 1985-12-10 Triten Corporation Coke cooler
DE3534991A1 (de) 1985-10-01 1987-04-02 Gutehoffnungshuette Man Drehrohrkuehler
SU1545069A1 (ru) * 1987-08-10 1990-02-23 Предприятие П/Я Р-6271 Теплообменник
SU1737241A1 (ru) * 1989-12-20 1992-05-30 Научно-Производственное Объединение "Техэнергохимпром" Холодильник дл сыпучего материала
AT398129B (de) 1991-01-14 1994-09-26 Waagner Biro Ag Drehrohrwärmebehandlungsanlage, insbesondere drehrohrofen
RU2035683C1 (ru) * 1991-06-27 1995-05-20 Сумской Государственный Университет Теплообменник типа "труба в трубе"
DE4406382C2 (de) 1994-02-26 1997-08-14 Metallgesellschaft Ag Drehkühler zum Kühlen von Schüttgut
JP4833736B2 (ja) * 2006-05-22 2011-12-07 新日本製鐵株式会社 外熱式ロータリーキルンを用いた廃棄物処理方法
RU2508389C1 (ru) * 2012-08-06 2014-02-27 Государственное унитарное предприятие "Институт нефтехимпереработки Республики Башкортостан" (ГУП "ИНХП РБ") Вращающийся холодильник для охлаждения сыпучих материалов
EP2889569A1 (en) * 2013-12-26 2015-07-01 Technip France Rotary cooler comprising a controlled sweep air system
RU2629281C1 (ru) * 2016-04-29 2017-08-28 Илья Павлович Рило Охлаждающий термосифон для глубинной термостабилизации грунтов (варианты)
JP6544597B2 (ja) * 2017-02-22 2019-07-17 環境・エネルギーＲ＆Ｄ合同会社 ロータリーキルン式ガス化炉

Also Published As

Publication number Publication date
CL2020002937A1 (es) 2021-04-09
EP3794295A1 (de) 2021-03-24
RU2771058C1 (ru) 2022-04-25
CA3099902A1 (en) 2019-11-21
ES2957358T3 (es) 2024-01-17
KR20210008082A (ko) 2021-01-20
MX2020012246A (es) 2021-04-13
PE20210532A1 (es) 2021-03-17
ZA202007283B (en) 2021-08-25
JP7286901B2 (ja) 2023-06-06
EP3794295C0 (de) 2023-07-26
JP2021523339A (ja) 2021-09-02
AU2019268508A1 (en) 2020-12-24
WO2019219233A1 (de) 2019-11-21
US20210215428A1 (en) 2021-07-15

Similar Documents

Publication Publication Date Title
JP4832287B2 (ja) 冷間加工された高強度シームレス耐食管の製造方法
CN102162069A (zh) 一种飞剪主传动大齿轮钢及其制造方法
WO2011051496A1 (de) Verfahren zum herstellen eines hohlkörpers
EP3625374A1 (de) VERFAHREN ZUR HERSTELLUNG EINES VERSCHLEIßFESTEN STAHLROHRS, VERSCHLEIßFESTES STAHLROHR UND VERWENDUNG EINES SOLCHEN STAHLROHRS
EP1391521A1 (de) Kühlplatte für metallurgische Öfen
DE102013106570A1 (de) Siebstange, Stangensieb und Verfahren zur Herstellung einer Siebstange
EP3794295B1 (de) Drehrohrapparat
WO2011080257A1 (de) Verfahren zur reparatur eines gehäuseteils eines flugzeugtriebwerks
EP2064388A1 (de) Verfahren zur herstellung eines walzenkörpers und walzenkörper
Sahin et al. Mechanical and metalurgical properties of friction welded aluminium joints
DE3807347A1 (de) Formkoerper aus mehreren metallschichten sowie verfahren zu ihrer herstellung
DE10048870C2 (de) Gehäuse für Kunststoff-, Metallpulver-, Keramikpulver- oder Lebensmittelverarbeitungsmaschinen und Verfahren zur Herstellung eines derartigen Gehäuses
Kashani et al. Improvement of wear resistance of hot working tool steel by hardfacing Part 2–Case study
DE2557413C2 (de) Drehrohrofen mit Satellitenkühler
US12000655B2 (en) Rotary tube apparatus
JPS5978794A (ja) 耐摩耗性を有する製鉄機械部品
Behrens et al. Investigation of load adapted gears and shafts manufactured by compound-forging
EP1565589B1 (de) Verwendung einer stahllegierung als werkstoff zur herstellung von rohrleitungen für kraftfahrzeuge
CN106854717B (zh) 一种激光制造连铸机出坯辊道的镍基合金粉末
EP2328708B1 (de) Verfahren zum verbindungsschmelzschweissen von dünnwandigen ummantelungen
DE102015116191A1 (de) Verfahren zur umforminduzierten Schweißnahtbehandlung
Gladkii et al. Surfacing in the USSR
Ebner Laser welding of structural component
DE940591C (de) Glatte oder profilierte Stahl-Walzen fuer warme Stahlbloecke
DE202022000408U1 (de) Stoffschlüssige Verbindung artungleicher, metallischer Werkstoffe mittels Elektronenstrahl insbesondere von Stahl mit Titan sowie Aluminium mit Kupfer

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20201211

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20211125

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

INTG Intention to grant announced

Effective date: 20230331

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE PATENT HAS BEEN GRANTED

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: LANGUAGE OF EP DOCUMENT: GERMAN

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 502019008673

Country of ref document: DE

U01 Request for unitary effect filed

Effective date: 20230811

U07 Unitary effect registered

Designated state(s): AT BE BG DE DK EE FI FR IT LT LU LV MT NL PT SE SI

Effective date: 20230821

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG9D

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2957358

Country of ref document: ES

Kind code of ref document: T3

Effective date: 20240117

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20231027

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20231126

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230726

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20231026

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20231126

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230726

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20231027

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230726

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230726

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230726

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230726

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230726