GB1602810A

GB1602810A - Rotary kiln having a satellite coder

Info

Publication number: GB1602810A
Application number: GB2292778A
Authority: GB
Original assignee: Kloeckner Humboldt Deutz AG
Current assignee: Kloeckner Humboldt Deutz AG
Priority date: 1977-07-29
Filing date: 1978-05-26
Publication date: 1981-11-18
Also published as: FR2398990A1; DE2734230C2; DE2734230A1; ES471922A1; FR2398990B3; DK336578A

Description

(54) A ROTARY KILN HAVING A SATELLITE COOLER (71) We, KLocKNR-HUMBoLDT-DEUTz AKTIENGESELLSCHAFT of Deutz-Mulheimer Strasse 111, 5 Koln 80, Federal Republic of Germany, a German Body Corporate, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to a rotary kiln having satellite cooling tubes arranged at the extraction end and attached to pipe connections which extend radially away from the kiln sleeve and whereby the kiln sleeve and the pipe connections are provided on the inside with a heat-insulating protective lining.

The protective lining usually comprises a fire-resistant brick lining substance which is subject to high static, dynamic and thermal loading during operation. Mechanical stress which encourage the formation and spread of tears in the brick lining occur as a result of the varying thermal expansion coefficient and elasticities of the brick lining on the one hand and of the kiln sleeve or the pipe connection on the other hand. These tears spread rapidly so that later there are breaks of whole parts of the brick lining the result of which is that their insulating effect disappears. It has been shown that the mutual penetration of functional and loading aspects is not recognized with the conventional types of formation and the superimposed effect of thermal, static and dynamic loads cannot be safely controlled.

More particularly an intensive flow of heat takes place directly into the transition region between the kiln sleeve and the pipe connection. The tension condition present at this point leads therefore to premature fatigue of the material of the kiln sleeve and considerably reduces its operational availability. Moreover. with these known embodiments the protective lining of the kiln sleeve is damaged when completely or partially exchanging the protective lining of the pipe connection for the purpose of repair or overhaul.

The invention seeks therefore to form the protective lining in the transition region between the rotary kiln and the satellite cooler so that the requirements with regard to resistance and insulation are reliably fulfilled and at the same time any overhaul work can be undertaken simply and economically.

According to the invention, there is provided a rotary kiln with satellite cooling tubes connected to the kiln by radially extending pipe connections at the material extraction end comprising separate heat insulative protective linings for the kiln sleeve and for the pipe connections, the lining for each pipe connection having a support arranged so as to be heat insulated with respect to the kiln sleeve and/or the pipe connection.

The protective lining of the pipe connection can be kept ready because of the separating points with respect to the protective lining of the kiln sleeve as a largely prefabricated component. This component can be built in or dismantled without destroying the protective lining of the kiln sleeve so that maintenance and repair work is simplified advantageously. Moreover, by providing joins the elasticity of the construction is increased in the transition region between the kiln sleeve and the pipe connection so that mechanical tension which results from the different deformation characteristics of the brick lining substance and kiln sleeve or the pipe connection respectively, is avoided. The protective lining of the pipe connection is provided with a support element which preferably comprises metallic material and acts as a support body increasing the strength.Since the support element is thermally insulated with respect to the pipe connection then even in the case where direct contact is present between the hot extraction material of the rotary kiln and the support element the flow - of heat into the aperture region of the kiln sleeve and the disadvantageous results already mentioned are avoided.

In accordance with a further refinement of the invention the protective lining and/ or the support elements are made up of segments. The segmental construction is a further measure in accordance with the invention and increasing the elasticity of the construction. In this way additional tension resulting from the different deformability of the brick lining substance and of metallic components is avoided. Because the deformation condition which changes cyclically with each rotation of the rotary kiln can be taken up advantageously by the yielding nature of the construction achieved in this way, without excessive loading taking place.

Moreover, the thermal expansion which is unavoidable during operation and to which metallic components are subjected is not hindered by this segmental construction so that any damaging effects resulting herefrom are avoided.

In another refinement of the invention the support element of the pipe connection comprises an annular metal body which is embedded in the protective lining. The supporting element embedded in the protective lining does not therefore have any direct contact with the pipe connection on the one hand or with the hot extraction material on the other hand which is conveyed through the pipe connection. The annular metal body which has been kept in readiness as a replacement part and which is lined either completely or partially ensures rapid exchange of the protective lining of the pipe connection if necessary whereby the protective lining of the kiln sleeve remains untouched.

In a further refinement of the invention the support element in the pipe connection is arranged on the inside of the protective lining and comprises wear-resistant material.

In this way the protective lining is given a high degree of shaping and abrasive resistance while at the same time the brick lining layer attached thereto in the direction of the pipe connection gives the entire arrangement the required insulating capacity.

There are also special advantages in this refinement if the segmental constuction is used. Thus for example the support element arranged on the inside can be divided up into segments which extend respectively over a part of the periphery. Part of the wear on the protective lining can be overcome by exchanging one or more support elements in simple manner so as to make savings in labour and costs. At the same time the requirements with regard to both resistance and insulation are fulfilled with respect to a high operational availability of the rotary kiln.

In accordance with a further refinement of the invention the support elements and the protective linings are fastened by means of tie rods to the pipe -connection. These measures in accordance with the invention bring about safe fastening within the pipe connection of both the protective lining and the support elements whereby an unnecessarily intensive heat conduction towards the pipe connection is avoided because of the relatively small cross-section of the tie rod.

The invention will now be described in greater detail, by way of example with reference to the drawings, in which: Figure 1 shows an extraction region of a rotary kiln simplified and in partial view; Figure 2 shows a connecting point between the pipe connection and the kiln sleeve according to II of Figure 1 in an enlarged and sectional view in accordance with the invention; Figure 3 shows a plan view III in accordance with Figure 2; Figure 4 shows another embodiment of the connecting point in accordance with the invention between the pipe connection and the kiln sleeve in an enlarged schematic view, and Figure 5 shows a plan view V in accordance with Figure 4.

In details Figure 1 shows the extraction region of a rotary kiln 1, the end of which is provided with several pipe connections 2 which are distributed evenly over the periphery of the kiln sleeve 3. Two of these pipe connections 2 are shown in the drawmg the remaining are only indicated as an attachment and are shown in broken lines.

The cooling tubes 4 of a satellite cooler are attached to these pipe connections 2.

Figures 2 and 3 show the transition point between the pipe connection 2 and the kiln sleeve 3 in section and in an enlarged view in the region II of Figure 1. In Figures 2 and 3 the kiln sleeve 3 is provided on its inside with a protective lining 5 which comprises a fire-resistant brick lining substance and is separated from the protective lining 7 of the pipe connection 2 by means of a join 6. The join 6 shows a cylindrical limit surface arranged coaxially with respect to the pipe connection 2 and between the two protective linings 5 and 7 and extends from the inner sleeve surface of the protective lining 5 directly up to the kiln sleeve 3.

The protective lining 7 projects in this way beyond the end of the pipe connetcion 2 at the kiln end, said pipe connection 2 having a welded connection with the kiln sleeve 3, into the protective lining 5 and is fixed positively at the point 8. The protective lining 7 of the pipe connection 2 is provided with a ring-like support element 9 which is provided at the kiln end with a collar 10 running round it and angular in section. The support element 9 is completely embedded in the fire-resistant brick lining substance up to a region 11 and constitutes an integral component of the protective lining 7 of the pipe connection 2.

The brick lining substance connected to the support element 9 is subdivided into segments in order to increase the elasticity of the protective lining 7, these segments being fixed with the aid of suitable anchoring elements 12 to the support elements 9, 10 and being delimited with respect to each other by means of joins 6, 6' (Fig. 3). Thus the segmental subdivision of the brick lining substance takes place both radially and axially of the pipe connection 2 so that sealing elements 13 which are like ring segments and brick lining elements 14 (like hollow cylindrical segments) are formed.

The size of the elements 13, 14 thus formed depends on the deformation of the kiln sleeve 3 and of the pipe connection 2 which is to be expected under the influence of static, dynamic and thermal loading during operation. Thus the most extensive subdivision possible should be sought after since in this case the deformation arising can be largely accommodated free of any hindrance so that the brick lining substance can follow the resilient deformation of the metallic kiln sleeve without excessive loading. In this way the tension arising can be kept within limits.

There is the possibility of keeping thc protective lining 7 in readiness as an either completely or partially prefabricated component iri order to be able to carry out tht repair and overhaul work in this region in the shortest time possible and in the simplest manner. Thus this prefabricated component can comprise the support ele ment 7, 1 1P for example, the sealing ele- ments 13 fixed to it, the brick lining elements 14 and an outer protective layer in the region 15 which has been partially appli d already. This protective layer in the region 15 also comprises a fire-resistant brick lining substance. This component is installed and dismantled from the inside of the kiln sleeve. The region 15 is then filled with fire-resistant brick lining substance.

This embodiment in accordance with the invention offers safe thermal protection of the transition region between the kiln sleeve 3 and the pipe connection 2. The hot extraction material leaving the rotary kiln is only in direct contact with the brick lining of the support eleemnt 9 the said brick lining largely preventing conduction of heat towards the pipe connection 2 because of its low heat conductivity. Even in the case of severe damage to the inner brick lining of the support element 9 the said elements 13, 14, there remains a sufficient mechanical and thermal protection of the pipe connection 2 and thus also of the transition region between the kiln sleeve 3 and the pipe connection 2.This is because the support element 9 opposes any damage to the parts of the kiln sleeve and excessive heating of the pipe connection is avoided by the fact that there is only one connection of very low heat conductivity between the support element 9 and the pipe connection 2 over the region 15.

Figures 4 and 5 show a further possibility of formation of the transition region between the kiln sleeve 3 and the pipe connection 2 in accordance with the invention. in this embodiment the protective sleeve 7 of the pipe connection 2 has several support elements 16 on its inside which are comprise wear-resistant material. These supdistributed evenly across its periphery and port elements 16 are connected to the pipe rods 17 and a plug connection 18 and can connection 2 separately with the aid of tie in this way be separately exchanged if necessary. Between the support elements 16 and the pipe connection 2 is located a protective layer 19 made of a fire-resistant brick lining substance which ensures the necessary heat insulation.

The plug connection 18 comprises an inserted part 19 which is fixed to the support element 16 and comprises a receiving part 20 which is fixed to the wall of the pipe connection 2. The insertion part 19 is surrounded positively by the receiving part 20 so that the tie rod 17 is relieved of transverse forces.

The protective lining 7 of the pipe connection 2 is separated from the protective lining 5 of the kiln sleeve 3 by means of a cylindrical join 6 which is arranged coaxially of the pipe connection 2 and extends up to the kiln sleeve 3.

This embodiment also shows an advantageous possibility of formation since the requirements both with regard to elasticity and resistance as well as to insulation are fulfilled. Furthermore, repair and maintenance work is simplified in this case to a considerable extent since installation and dismantling of individual or several support elements 16 can take place simply and rapidly.

Further variations with respect to the constructional formation of the support elements and their fixing to the pipe connection are conceivable without going beyond the framework of the invention.

WHAT WE CLAIM IS: 1. A rotary kiln with satellite cooling tubes connected to the kiln by radially extending pipe connections at the material extraction end comprising separate heat insulative protective linings for the kiln sleeve and for the pipe connections, the lining for each pipe connection having a support arranged so as to be heat insulated with respect to the kiln sleeve and/or the pipe connection.

2. A rotary kiln according to Claim 1, wherein the protective lining and/or the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. The brick lining substance connected to the support element 9 is subdivided into segments in order to increase the elasticity of the protective lining 7, these segments being fixed with the aid of suitable anchoring elements 12 to the support elements 9, 10 and being delimited with respect to each other by means of joins 6, 6' (Fig. 3). Thus the segmental subdivision of the brick lining substance takes place both radially and axially of the pipe connection 2 so that sealing elements 13 which are like ring segments and brick lining elements 14 (like hollow cylindrical segments) are formed. The size of the elements 13, 14 thus formed depends on the deformation of the kiln sleeve 3 and of the pipe connection 2 which is to be expected under the influence of static, dynamic and thermal loading during operation. Thus the most extensive subdivision possible should be sought after since in this case the deformation arising can be largely accommodated free of any hindrance so that the brick lining substance can follow the resilient deformation of the metallic kiln sleeve without excessive loading. In this way the tension arising can be kept within limits. There is the possibility of keeping thc protective lining 7 in readiness as an either completely or partially prefabricated component iri order to be able to carry out tht repair and overhaul work in this region in the shortest time possible and in the simplest manner. Thus this prefabricated component can comprise the support ele ment 7, 1 1P for example, the sealing ele- ments 13 fixed to it, the brick lining elements 14 and an outer protective layer in the region 15 which has been partially appli d already. This protective layer in the region 15 also comprises a fire-resistant brick lining substance. This component is installed and dismantled from the inside of the kiln sleeve. The region 15 is then filled with fire-resistant brick lining substance. This embodiment in accordance with the invention offers safe thermal protection of the transition region between the kiln sleeve 3 and the pipe connection 2. The hot extraction material leaving the rotary kiln is only in direct contact with the brick lining of the support eleemnt 9 the said brick lining largely preventing conduction of heat towards the pipe connection 2 because of its low heat conductivity. Even in the case of severe damage to the inner brick lining of the support element 9 the said elements 13, 14, there remains a sufficient mechanical and thermal protection of the pipe connection 2 and thus also of the transition region between the kiln sleeve 3 and the pipe connection 2.This is because the support element 9 opposes any damage to the parts of the kiln sleeve and excessive heating of the pipe connection is avoided by the fact that there is only one connection of very low heat conductivity between the support element 9 and the pipe connection 2 over the region 15. Figures 4 and 5 show a further possibility of formation of the transition region between the kiln sleeve 3 and the pipe connection 2 in accordance with the invention. in this embodiment the protective sleeve 7 of the pipe connection 2 has several support elements 16 on its inside which are comprise wear-resistant material. These supdistributed evenly across its periphery and port elements 16 are connected to the pipe rods 17 and a plug connection 18 and can connection 2 separately with the aid of tie in this way be separately exchanged if necessary. Between the support elements 16 and the pipe connection 2 is located a protective layer 19 made of a fire-resistant brick lining substance which ensures the necessary heat insulation. The plug connection 18 comprises an inserted part 19 which is fixed to the support element 16 and comprises a receiving part 20 which is fixed to the wall of the pipe connection 2. The insertion part 19 is surrounded positively by the receiving part 20 so that the tie rod 17 is relieved of transverse forces. The protective lining 7 of the pipe connection 2 is separated from the protective lining 5 of the kiln sleeve 3 by means of a cylindrical join 6 which is arranged coaxially of the pipe connection 2 and extends up to the kiln sleeve 3. This embodiment also shows an advantageous possibility of formation since the requirements both with regard to elasticity and resistance as well as to insulation are fulfilled. Furthermore, repair and maintenance work is simplified in this case to a considerable extent since installation and dismantling of individual or several support elements 16 can take place simply and rapidly. Further variations with respect to the constructional formation of the support elements and their fixing to the pipe connection are conceivable without going beyond the framework of the invention. WHAT WE CLAIM IS:

1. A rotary kiln with satellite cooling tubes connected to the kiln by radially extending pipe connections at the material extraction end comprising separate heat insulative protective linings for the kiln sleeve and for the pipe connections, the lining for each pipe connection having a support arranged so as to be heat insulated with respect to the kiln sleeve and/or the pipe connection.

2. A rotary kiln according to Claim 1, wherein the protective lining and/or the

support comprise segments.

3. A rotary kiln according to Claim 1, wherein the support of the protective lining of the pipe connection comprises a rink-like metal body which is embedded in the protive lining.

4. A rotary kiln according to Claim 1 or 2, wherein the support is arranged in the pipe connection on the inside of the protective lining and comprises wearresistant material.

5. A rotary kiln according to any one of the preceding Claims, wherein the support and the protective lining are fixed to the pipe connection by means of tie rods.

6. A rotary kiln with satellite cooling tubes substantially as described herein with reference to the drawings.