Abstract:
In order to create a cyclone separator with segmented immersion pipe for cement clinker manufacturing system with cyclone suspension type heat exchanger system, whereby the releasable immersion pipe segment fastening is dependable and is distinguished by a long service life, it is inventively proposed to secure the immersion pipe segments at their upper end with releasable screw bolts, whereby the screw bolts are arranged in spacer sleeves distributed around the immersion pipe circumference that respectively comprise at least one window-like opening at the outside for the access of ambient air as coolant for the immersion pipe segment fastening.

Description:
BACKGROUND OF THE INVENTION 
     The invention is directed to a cyclone separator, particularly for direct heat transmission from the hot exhaust gasses of a rotary tubular kiln/cyclone suspension type heat exchanger for cement clinker manufacture onto the raw cement meal, having tangential delivery of gas and raw meal, product discharge in the lower cyclone area and having an immersion pipe for gas elimination that is composed of a plurality of segments, which immersion pipe, projects centrally from above into the cyclone separator and is suspended at the cyclone ceiling, whereby the immersion pipe segments have their upper end releasably connected by screw bolts to the gas withdrawal conduit insulated by a refractory lining. 
     In systems for manufacturing cement clinker from raw cement meal, the raw meal is thermally treated by pre-heating, calcining, sintering and cooling, whereby the exhaust gas stream of the sintering unit and the exhaust air stream of the cooling unit from the clinker cooler are utilized, either separately or in common, for the calcination of the raw meal in a calcining unit supplied with fuel that is still located outside the sintering furnace. The preheating unit is usually composed of a plurality of suspension type heat exchanger cyclones arranged above one another through which the raw cement meal successively migrates in a combined co-current, counter-current stream relative to the hot exhaust gas of the calcining unit or, respectively, of the rotary tubular kiln. The product material pre-calcined in the calcining unit is thereby separated from the hot gas in the lowest cyclone of the cyclone suspension type heat exchanger system and is introduced into the rotary tubular kiln. It is self-evident that the hot gas cyclones of the cyclone suspension type heat exchanger line, particularly the lowest cyclone that comes into contact with hot gas and hot meal having a temperature of, for example, 700 through 950° C., are exposed to a high mechanical, chemical and thermal stressing and, thus, to high thermo-chemical and abrasive wear. This is especially true of the immersion pipe centrally projecting from above into the cyclone separator. 
     Given a cyclone separator exposed to these high stresses, it is therefore already known (DE-C-32 28 902) to compose the immersion pipe of a plurality of segments and to suspend the immersion pipe segments at the cyclone ceiling with a hook-shaped fashioning or to releasably connect the immersion pipe-segments with radially arranged screw bolts to the gas discharge conduit of the cyclone that is insulated by a refractory lining, in order to avoid deformations at the immersion pipe cladding even given high, thermal alternating stresses, and in order to be able to replace individual immersion pipe segments with comparatively little time and work expenditure, in case of wear. However, the screwed connections of the immersion pipe segments were thereby not protected against the thermo-chemical stresses, with the consequence that the risk was not precluded that the screwed connection unscrewed after a certain time, after which, given the lack of further safety measures, the appertaining immersion pipe segment could drop down into the cyclone separator. 
     SUMMARY OF THE INVENTION 
     The invention is therefore based on an object of creating a cyclone separator with segmented immersion pipe for cement clinker manufacturing systems with a cyclone suspension type heat exchanger system, wherein the releasable immersion pipe segment fastening arrangement is dependable and is characterized by a long service life. 
     This object is inventively achieved in accordance with the features of the invention described below. 
     What is characteristic of the inventive cyclone separator with segmented immersion pipe, whereby the immersion pipe segments have their upper ends releasably connected by approximately radially arranged screw bolts to the cyclone ceiling or, respectively, to the cyclone gas withdrawal conduit, is that the screw bolts are arranged in spacer sleeves arranged distributed around the circumference of the immersion pipe that outwardly (i.e., lying radially at the outside) respectively comprise at least one window-like opening for the access or inlet of ambient air as a coolant for the fastening arrangement of the immersion pipe segment. What this design achieves is that the screw bolts can conduct and eliminate the high temperatures acting proceeding from the inside of the immersion pipe, which high temperatures can amount to about 900° C. without further ado in the lower region of a cyclone suspension type heat exchanger system of a cement clinker manufacturing system given hot gas cyclones, into the ambient air, as cooling air, accessible through the window-like openings of the spacer sleeves. It would also be possible to provide the inside space of the spacer sleeves, together with the screw bolts, with forced aeration by a blower or the like through the window-like openings, as well as, potentially, to even provide the inside space with an admission and discharge for a liquid coolant. 
     According to a further feature of the invention, the head of the screw bolt arranged at the inside of the immersion pipe, in a corresponding recess of the immersion pipe segment, as well as in the spacer sleeve, is respectively covered by a cover, so that the screw bolts are protected against mechanical and thermo-chemical stresses proceeding from this side. Overall, a long service life of the inventive, releasable fastening arrangement of the immersion pipe segments of a thermo-chemically highly stressed cyclone separator thereby derives, particularly for the hot zones of a cyclone suspension type heat exchanger line. 
     According to a further feature of the invention, the immersion pipe segments can comprise outwardly angularly projecting projections with a hook-shaped cross section at their upper end with which the immersion pipe segments engage into a web that extends upward from the inside of the spacer sleeves. This combined fastening of the immersion pipe segments offers a high degree of dependability for the fastening arrangement. Further, assembly is facilitated when the segments are hooked in first, as a result whereof the weight of the segments is relieved, for when the suspended immersion pipe segments are subsequently aligned and screwed. 
     For connecting two respective immersion pipe segments arranged next to one another and under one another, i.e., a total of four immersion pipe segments, a retainer plate having four transverse bolts that are plugged through four corresponding holes in the four adjoining comers of the immersion pipe segments and covering the crossing-joint region at one side of the segments, can be arranged in the crossing-joint region in which two immersion pipe segments neighboring side-by-side and two immersion pipe segments arranged therebelow adjoin one another, whereby cross-bolts for securing the retainer plates are then secured on the four transverse bolts that have been plugged through. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The invention and further features and advantages thereof are explained in greater detail on the basis of the exemplary embodiment schematically shown in the figures. 
     FIG. 1 is a partial vertical sectional view through the inventive immersion pipe segment fastening along the line I—I of FIG.  2 . 
     FIG. 2 is a partial side elevational view of the immersion pipe segment fastening of FIG. 1 seen from the right. 
     FIG. 3 is a partial horizontal sectional view through the immersion pipe segment fastening along the line IIIA—IIIA and including a section taken along the line IIIB—IIIB of FIG.  2 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Excerpted from a cyclone separator, FIG. 1 shows a cyclone ceiling  10  that has its inside provided with a refractory lining  11 . Hot gas and raw cement meal of a system for manufacturing cement clinker enter tangentially into the cyclone. For the gas elimination, an immersion pipe that is composed of a plurality of segments arranged in rows and columns and suspended at the cyclone ceiling  10  projects centrally from above into the cyclone separator. Two immersion pipe segments  12  and  13  arranged next to one another can thus be seen in FIG. 2, the further immersion pipe segments  14  and  15 , etc., being in turn attached to these at the bottom. A structure such as gas discharge conduit  17  defining an outer circumference provided with a refractory lining  16  at the inside and defining an inner circumference departs centrally upward from the cyclone ceiling  10 . 
     The immersion pipe segments  12 ,  13 , etc. of the uppermost row define a circumference approximately the same size as the inner circumference of the refractory lining. Distributed around the immersion pipe circumference at the top of the uppermost row of segments are outwardly angular salient hook-shaped projections  18  with which the immersion pipe segments engage onto a web or rim  19  that extends upward from a radially inner end of spacer sleeves  20  which are arranged in a circle having a circumference just larger than the circumference of the pipe segments. Seated on the cyclone ceiling  10  and distributed around the immersion pipe circumference, the spacer sleeves  20  are secured to the gas discharge conduit  17  by bolts or other fastening arrangement and are arranged approximately radially relative to the immersion pipe center. The spacer sleeves  20  each extend from the outer circumference of the gas discharge conduit to the inner circumference of the refractory lining. A plurality of approximately radially arranged screw bolts  21 , with which the immersion pipe segment  12  is releasably connected to the insulated gas discharge conduit  17 , are respectively arranged in the spacer sleeves  20 , with one bolt  21  in each sleeve  20 . 
     Spacer arrangements other than individual sleeves may be provided so long as they extend from the outer circumference of the structure at the gas discharge opening in the ceiling of the cyclone separator to the inner circumference, and include an opening in the spacer arrangement and the structure adjacent each screw bolt to provide access for ambient air to flow into a space surrounding each screw bolt. 
     For facilitating assembly, the immersion pipe segments  12  etc., are first hooked onto the spacer sleeves  20  or, respectively, their webs  19 , with the hook-shaped projections  18 , as a result whereof the weight of the segments is relieved. The segments are subsequently aligned and screwed. 
     Inventively, the spacer sleeves  20 , distributed around the immersion pipe circumference and wherein the screw bolts  21  are arranged respectively, and each have at least one window-like opening  22  toward the radial outside through the gas discharge conduit  17  for the access of ambient air as a coolant for the fastening arrangement of the immersion pipe segments. In this way, the screw bolts  21  can conduct an eliminate or discharge the high temperatures acting from the inside of the immersion pipe well to the outside of the immersion pipe. Added thereto is that the head of the screw bolts  21 , which is arranged at the inside of the immersion pipe in a corresponding recess of the immersion pipe segment  12 , etc., as well as in the spacer sleeve  20 , is respectively covered by a cover  23  that protects the fastening arrangement of the immersion pipe segments against the high thermo-chemical stressing. After being mounted, the cover  23  can also be secured to the immersion pipe segment  12 , etc., by a tack weld. At any rate, the inventive fastening arrangement of the immersion pipe segments is characterized by a long service life. 
     It can also be seen in FIG. 1 that the screw bolts  21  have a thickened or enlarged head  24  that is positioned in a recess of a cap  25  with which the immersion pipe segment  21  is clampable to the inside end of the spacer sleeves  20  or, respectively, to their inside end web  19 . At their radially outwardly disposed end, the screw bolts  21  comprise nuts  26  with which they are supported at the radial outside end of the spacer sleeves  20  via saucer springs or spring washers  27  and via a disk or flat washer  28 . 
     In the crossing/joint region wherein respectively two immersion pipe segments ( 12 ,  13 ,  14 ,  15 ) neighboring one another side-by-side and two arranged therebelow adjoin, a retainer plate  29  covering the crossing/joint region at one side of the segments can be arranged, this retainer plate  29  having four cross-bolts  30 ,  31 ,  32 ,  33  that are plugged through four corresponding holes in the four adjoining comers of the immersion pipe segments, whereby cross brackets  34 ,  35  for securing the retainer plate  29  are secured on the four cross-bolts that are plugged through. As shown, the cross brackets  34 ,  35  can be vertically arranged; however, they can also be horizontally or diagonally arranged. The outside contour of the retainer plate  29  can be rectangular, quadratic, round, cross-shaped, etc., and it can also comprise a central recess  36 , for example a round hole, which contributes to a weight-saving in the retainer plate  29 . The lowest row of the immersion pipe segments is expediently secured at the bottom only with cross brackets  37  providing a horizontal connection. Although the retainer plates  29  are illustrated as being positioned on the radial exterior of the immersion pipe segments, with the cross brackets  34 ,  35  being positioned on the radial interior of the immersion pipe segments, this arrangement could also be reversed with the retainer plates positioned on the interior and the cross brackets positioned on the exterior. 
     As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that we wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of our contribution to the art.