WO2012093194A1

WO2012093194A1 - 3d- expansion joint in refractory lining

Info

Publication number: WO2012093194A1
Application number: PCT/FI2011/000056
Authority: WO
Inventors: Veijo Pitkänen
Original assignee: Patenttimies V. Pitkänen Oy
Priority date: 2011-01-04
Filing date: 2011-12-29
Publication date: 2012-07-12
Also published as: FI123091B; FI9485U1; FI20110002A; FI20110002A0; FIU20110203U0

Abstract

The object of this invention is a construction and a method to make a joint point tight in a ceramic construction between two construction parts where the governing thermal movement consists of two or three dimensional movements of the construction parts. By the method according to the invention, a 3D expansion joint is achieved where the thermal movement containing different direction vectors is controlled in two different joint points (C, D) of the ceramic linings of a plant so that the joint remains essentially tight under all operation conditions. The height wise / length wise thermal movement takes place in the joint point (C) so that the middle element ring behind the overhang moves in the expansion space (7) the measure of this thermal movement component and the movements to the other directions take place in the joint point (D) when the plane surfaces (101.1, 1.5) that meet there move in relation to each other at the level of the plane surfaces.

Description

3D- EXPANSION JOINT IN REFRACTORY LINING

The object of this invention is a 3D expansion joint between two parts of a refractory ceramic lining. It comprises of two joint points, a middle element ring between them, moving devices to fix the middle element ring to the first part of the construction and for moving in relation to it height wise and length wise and the support parts to support it to the other construction part so that the support points of the middle element ring in the other construction part can move essentially to the normal directions of the movement directions of the middle element ring.

The usage fields of the invention are the expansion joints between the refractory ceramic linings where there is a so called space line between the temperature movement starting and ending points. That is, if we think that there are right-angled co-ordinates of three axis in the expansion joint area where one axis is in the direction of the thermal movement components that move those components closer or farther in relation to each other (=height wise/length wise) and the other two axis are normal in relation to it and each other, so the expansion movement has two or three components in the directions of the axis of these co-ordinates.

There are before mentioned expansion joints for instance in the fluidized bed boilers in the channels between the furnace and the cyclone, in the channels between the cyclone and the loop seal and also in the channels between the loops seals and the furnace. In these points the height wise / length wise thermal movement component can push the construction closer to each other or farther from each other when the equipment is hot and respectively when it gets cooler into the opposite direction. These directions and dimensions of the thermal movements depend upon the support point locations of the equipment parts.

Nowadays, these joint points are made by leaving an open straight space between the construction parts and by filling this space with elastic ceramic fibre. This space must be so big that the thermal movement height wise / length wise can take place without the ceramic linings of the construction parts bumping each other. In practise, this space is left even greater so that there would not be the danger of bumping.

So that the joint would be tight in all the conditions: cold, hot and between these two extremes, a solution has already been made for about twenty years ago, but this solution has not been able to be applied in practise because it has been seen too complicated to make and install. This solution is presented in the Finnish patent publication number 87271. In this solution the expansion joint is composed of two joint points where one controls the height / length thermal movements and the other side wise thermal movements. Additionally, the solution is composed of a middle zone between these two joints that is capable of moving in relation to the other construction part height / length wise and side wise in relation to the other. These movements are controlled by movement and support devices so that the construction stays in theory tight under all the usage conditions of the boiler.

The drawback of the prior art technique is in the case of the open joint that the construction is not tight in any phase of operation because the space between the construction parts must be made so big that there is no danger of bumping of the parts. The elastic ceramic fibre material wears off very quickly from the joint because of the flow of the process sand in spite of that this fibre filling is supported to its place with different nets made of different refractory materials. The result is that the hot process sand gets behind the lining to the bodywork and the damages it causes.

The greatest drawback of the solution of the patent publication 87271 is that it has shown to be too complicated to realise in practise. There have been so many risk and uncertainty factors that one has not obtained realisations during the twenty years that have passed.

The before mentioned solution has later been changed so that it is possible to realise it in practise and this solution has been presented in the Finnish patent application number 20110002. It is a way by which the construction of the patent publication number 87271 solution principle can be realized in practise. According to this method the refractory linings of the construction parts are formed in their joint areas so that one makes a bracket to one of the linings and the other lining is made to end to the flat surface and one installs the middle element ring via outside in the space between them that is capable of moving in relation to the construction part with the bracket in only one back and forth direction and in relation to the other construction part only essentially in normal directions. Thus the situation has been achieved where the 3D thermal movement is dealt with in two different joint points.

The intention of this invention is to achieve such a 3D expansion joint that the drawbacks of the prior art technique can be avoided and the strong prejudices towards it can be avoided. The characterizing features have been presented in the characterizing part of the claims 1, 9 and 10.

The greatest advantage of the invention in relation to the prior art technique (Patent number 87271) is that the 3D expansion joint can be made beforehand by prefabricating it in a workshop and then by installing this prefabricated element to the boiler joint parts as one entity or as divided in some parts. By this method, a great accuracy of installation is achieved as well as can be made sure beforehand that the joint works and thus a great certainty of operation and rapid installation and very favourable total solution is achieved. All this leads into considerably less repair work and as the unexpected shutdowns are left out into great economical savings.

The invention is described in the drawings of this application as follows: Fig 1 presents a typical usage object for the invention, that is, a cross section of a round vertical channel between the cyclone sand feedback loop seal of a circulating fluidized bed boiler before installing the prefabricated element according to the invention,

Fig 2 presents the section of the fig 1 in the point A-A,

Fig 3 presents a prefabricated element,

Fig 4 presents a cross section of the prefabricated element of fig 3 in the point B-B,

Fig 5 presents a cross section of the channel of the fig 1 after the prefabricated element according to the invention has been installed,

Fig 6 presents a section of the previous fig in the point C-C,

Fig 7 presents a similar section as above of a horizontal channel,

Fig 8 presents an isometric section of a prefabricated element put together and test assembled for the transportation and installation,

Fig 9 presents an isometric cross section of a 3D expansion joint according to the invention.

The composition and the operation of the 3D expansion joint according to the invention will be explained with references to the figures.

The place to use the expansion joint according to the invention is cylindrical in this example, inside diameter Di 2000 mm vertical channel that is situated between the boiler cyclone and the sand return loop seal. The frame of the vertical channel is made of plate and thus the lining in turn is not cooled by the construction. This means that the lining comprises both of an insulating layer and a wear resistant surface layer and its total thickness is typically about 300 - 400 mm. The 3D expansion joint according to the invention is made of a prefabricated element E (figures 3, 4 and 8) that is placed between the construction parts (A and B, figure 2) of a boiler. The refractory ceramic linings 100, 101 of the construction parts are installed in such a way that the lining 101 of the lower construction part B ends to the plane surface 101.1 that is at the level of the upper surface of the bellows plate 104 and the lining 100 of the upper construction part A about 300 - 400 mm above the bellow plate 103. In this example, the bellow have been installed to the construction parts A and B so that the measure between them is about 400 mm. The bellow plates 103, 104 have been fixed to the construction parts of the steel frames 105, 106 of the boiler and they are parallel and in a horizontal position. They have been made of so thick steel plate that they are strong enough for the solution according to the invention. The prefabricated element E has been made so that the inner part 6.1 (figure 3) of the flange has an overhang 4 (figure 4) of ceramic material. The overhang 4 follows the shape of the circle of the lining of the construction part A and so it is in this case round. The overhang 4 has been anchored to the flange 6 using the prior art technique either by masonry anchors or for example bolts. The ceramic middle elements 1 have been installed behind the overhang 4 in such a way that their inner surface 1.1 is in a distance of the margin from the back surface 4.1 of the overhangs 4 and that the overhang 4 and the overhangs of the middle elements 1.2 are measure b (figure 6) interlocked with each other. In practise, the before mentioned margin can be made correct by installing a thin ceramic elastic fibre sheet between the surfaces at the same time with the middle elements. The situation presented in the figure 4 is also the situation of the transportation and the installation of the prefabricated element E when the middle elements 1 have been lifted up to the expansion space 7 (figure 6). The middle elements 1 are sector shape parts that together form a full 360 degree middle element ring and the inside arch measure of which in this example is about 400 - 500 mm. Their size can be any size suitable for the situation. The joints 5 (figure 8) between the middle elements 1 are either level or differing from it, so called tongue-and-groove joints or double rebating joints. The cross section of the middle elements 1 is a polygon, at the upper end there is narrower overhang 1.2 and at the lower part a wider part 1.3 and in the middle a part 1.4 that connects these two. Two parallel slides of the transfer gear 2,1 have been fixed to each middle element 1 using anchoring parts 2.3. The transfer gear bodies 2.2 have been connected to the slides 2.1 in such a way that these parts can only move height wise and length wise in relation to each other (in this example height wise). The gap between them is sufficiently small so that the movement sidewise between them cannot take place and thus the mechanism is solid. The frames 2.2 have been welded to the outer part 6.2 of the flange 6 that is above them and so the middle elements 1 can only move height wise in relation to the construction part A. Above the overhangs 1.2 there is an expansion space 7 (figure 6) and its height h, that is the sum of the height wise expansion components plus a security tolerance measure. In this example, the sum of the components is 100 mm and the height of the expansion space is 125 mm. So the flange 6 is made of two parts where the inner part 6.1, that is the part that is upon the hangover 4 is made of the refractory steel and the outer part 6.2 that is above the frame 2.2 is made of less alloyed steel. Their thickness is for instance about 10 - 12 mm and these parts have been joined using consoles 6.3.

The before described prefabricated element E has been made to contain four parts so that each part is a section of 90 degrees (figure 3). These sectors are transported to the work site packed in the transportation package for the installation. That is to say that the middle elements 1 have been locked into their upper position during the transportation and installation using cotters or other similar things that lock the slides 2.1 and their bodies 2.2 in relation to each other.

There is a space 107 (figure 2) between the construction parts A and B, and thus its height is about 400 mm. The prefabricated element E the installation height d (figure 4) of which is less than this measure is installed to the space 107 between the construction parts, the locking of the middle elements is opened and the flange 6 and the overhangs 4 and the transmitter bodies 2.2 are lifted up and the outer part 6.2 of the flange is welded to the bellow plate 103 (figure 6) and the consoles 6.3 are welded to the frame 105 of the construction part A either directly or using installation pieces. If there is doubt about that the roundness of the frame 105 is not dimensionally accurate, the consoles 6.3 will be manufactured with spacious measures and fixing to the frame 105 is made by welding installation pieces to the consoles 6.3 and the frame 105.

When installing the prefabricated element E to its place, good use is made of the support parts 2.1.1 that have been fixed to the lower parts of the slides 2.1. Each of these support parts is by construction a screw with a ball in its down end in the screw hole of the end surface 2.4 of the slide. The support pieces have been wound so much out of the end surfaces 2.4 that they are more out than the end surfaces 1.5 of the middle elements and thus the prefabricated element can be pushed into the space 107 supporting on the rolling balls of the support parts 2.1.1, and at the same time, the friction contact between the middle element surface 1.5 and end surface 101.1 of the ceramic lining of the other construction part B can be avoided. After fixing the first construction part A of the prefabricated element E, a 2 mm ceramic elastic fibre plate is installed between the surfaces 101.1 and 1.5 and the support parts 2.1.1 are screwed inwards so much that the distance e between the before mentioned surfaces is about 1 - 2 mm.

in the figure 7 the expansion joint like in the above example has been described with the difference that the channel where it has been installed is in the horizontal position. In this case, there is a power part 8 between the slides 2.1 and the flange of the transmitters, like pre-stressed springs. The task of the springs is to ensure the contact under all condition between the support parts 2.1.1 and the bellow plate 104 of the other construction part B and thus the expansion joint is essentially tight under all the conditions, that is when cold, warm, during shutdown and start-up. The springs can be produced to be cartridges that are then placed to the places reserved for them and when the locking of the springs is loosened they are triggered and they load the slides 2.1 with a power that is suitable for the situation. It can be seen in the figures 6 and 7 drafted with dash lines the lining work of the construction part A that is done as the last phase of the work. The areas 9 are lined with isolating and surface lining materials using molds and after it the 3D expansion joint construction according to the invention is complete.

In the figure 9, there is an isometric cross section about a ready 3D expansion joint according to the invention in a vertical channel with a diameter of about 2000 mm.

The 3D expansion joint according to the invention can be realised in any shape of channel. The channels in the fluidized bed boilers between the furnace and the cyclones are typically rectangles by their cross section. They are mostly horizontal and their height can be 2 - 10 m and width 1 - 5 m. The length of the joint can thus be even 30 m around in which case the prefabricate element E of the expansion joint according to the invention comprises many, even over 20 parts. These parts will be installed one at a time one after each other in the expansion joint.

In the same way, the frame construction of the boiler where the expansion joint according to the invention is used can also be cooled differing from the not cooled plate construction. In practise, it means a tube construction or in some cases comprising of two sheet casings containing box type structure. A very good example about this kind of tube construction is the before mentioned channel between the furnace and the cyclone where the tubes of two construction parts and the fins between them form the pressurized bodies that, when meeting, move differently by the effect of the thermal movements in the joint. In this construction, the thickness of the ceramic lining in the joint is much thinner than in a not cooled construction. The starting point of the realisation of the 3D expansion joint according to the invention is always the surface line of the inside linings and thus the dimensioning and fixing of the flange 6 to the frame of the construction part A and to the bellow plate are defined accordingly. The surface line of the middle elements 1 can be different from the surface lines of the linings of the construction parts, in which case it is possible for instance to adjust the flange 6 fixing points so that they come to the suitable places. The prefabricated element E can also be realised so that the sidewise expansion movement at the joint point is taken into account in the building phase so that when the plant is hot there are no dents that would hinder the flow in the joint point D.

There can be a suitable amount of the transmitters 2 for the situation in each expansion joint according to the invention. How many, is defined among other things by their total length and the measure b. The greater the expansion space 7 is needed the greater are the maximum lengths of the transmitters and the firmer they need to be built. The construction and operational mechanism can be any if only the possibility of the movement back and forth of the slide 2.1 and the body 2.2 in relation to each other and a sufficiently firm construction are achieved.

The overhang 4 that has been fixed to the flange 6 can be made either by casting it to its place using masonry anchoring or by installing it to the flange 6 using prefabricated pieces. In the first mentioned case, the overhang can be divided into parts using tension neutralizing joints 10. In the latter case, the fixing of the parts can be done using for instance bolts the material of which is high temperature resistant steel. In both cases, the joints 10 can be either level joint surface type or bursting joint surface type.

The power part 8 can be, in addition to springs, for instance pneumatic, hydraulic or lever equipment exploiting the gravitation. In the case of a spring the material can be for instance Mimonic or corresponding material where the heat resistance is sufficient for the conditions.

The flange 6 can be fixed to its place in some cases for instance by bolts. The middle elements 1 can also consist of one or more isolating background layers in which case they are built in two or multi layered construction. To the back surface of the middle elements, for instance to the gaps between the transmitters, a ceramic fibre mat can also be installed and so in the connection of the production of the middle elements anchoring wires for this layer are installed. Likewise, the expansion space 7 can be filled with elastic fibre.

The cross section shape of the middle elements can be any that is suitable for the situation. In some cases, it can be for instance rectangular in which case making it sufficiently thick, a sufficiently large joint area can be ensured in the joint point D. A nice shape of the linings in the joint area can thus be achieved for instance by a bevel part of the linings 101 of the other construction part B. The size of the middle elements 1 and the overhang 4 can be defined in each case separately. The size of the heat movements is the decisive factor in measuring these cross sectional surfaces. Their length in the direction of the circle is defined among other things by the factors of their assembly and this measure is also defined case by case in each situation. The size of the middle elements 1 in turn is meaningful in the amount of the transmitters 2 for each middle element 1.

Cuttings according to the prior art technique can be made to both inside and outside of the inner part 6.1 of the flange 6 to balance the heat expansion of the flange. These cuttings are made in all the spaces between the consoles 6.3.

In cases where supporting the flange 6 to the frame 105 of the first construction part A is not necessary the first construction part A can be lined before putting the prefabricate element E to its place also in the area 9. In this case, this lining ends to the lower level of the bellow plate 103. In case of a cooled channel construction where the lining thickness is small this construction can be possible.

The flange 6 can also be a placed consisting only of one ring/frame. This alternative can come into question in connection of the cooled construction, in which case due to the thinner lining thickness it is not a good idea to make it reach much more inside than the frame 105 of the first construction part A. The material selections of the flange are in each case defined separately and all these parts or a part of them can be of refractory material.

The 3D expansion joint according to the invention can also be made so that in connection of linings of the first construction part A the overhang 4 is formed to this lining and in this case the space 107 is the space between the overhang 4/bellow plate 103 and the other construction part B. After this, the middle elements 1 equipped with the transmitters 2 are installed via outside to this space as a tight circle. The bodies 2.2 of the transmitters are fixed to the bottom plate 103 of the first construction part A and a support is installed between middle elements 1 and the other construction part B using support parts 2.1.1. The tolerances and the gaps between the parts are always arranged as big as necessary using the same technique as described in this document before. In the application of this example according to the invention it is especially central and inventive that the middle elements are put to their places via outside and thus the building of the 3D expansion joint is sufficiently simple and favourable and on the other hand it can be made sure that its quality meets the very demanding operation conditions.

The support parts 2.1.1 can be constructions like for instance screws or axles that do not have in their end a before mentioned ball. As an example of this, a standard measure machine screw can be mentioned the head of which is essentially flat.

The ceramic plane surfaces that meet at the joint point D can also be placed facing each other so that in the beginning of the operation of the 3D expansion joint according to the invention they can rub against each other during the thermal movements so that they fit exactly to each other. In this case, the support parts 2.1.1 must be placed in such a position that after this rubbing they support the rubbed parts against each other in order to avoid a greater abrasion of these ceramic surfaces and thus the mechanic load of these surfaces in relation to each other is avoided.

The interlocking of the overhang 4 and the middle elements overhangs 1.2, that is measure b, can be set so that it is sufficient for the operation conditions of the joint even when the measure b is its smallest. The smallest value of this measure can vary for instance in the limits of 5 - 50 mm. For the sake of the clarity, it can be mentioned that the greater it is in its smallest the longer the overhang 4 must be.

It is worth noticing that even though this example sticks to one example solution that is favourable for the invention, however, it is not the intention to limit the use of the invention only for this type of example, instead, many variations are possible within the inventive idea presented in the claims.

Claims

1. a 3D expansion joint in a refractory lining which joint consists of

o two joint points (C), (D),

o a ceramic middle element the size of which is the same as the perimeter of the joint points

(C, D) and that is composed of one or more middle elements (1),

o at least one transmitter (2) that has been fixed to the middle element (1) and to the first construction part (A) and which transmitter (2) contains a slide (2.1) and body (2.2) or corresponding things,

o a support height wise / length wise between every transmitter (2) and the other construction part (B) that has been achieved using at least one power part (8) and/or the gravitation, and which expansion joint has been made so that o that the ceramic overhang (4) that has been fixed to the first construction part (A) and the overhangs (1.2) belonging to the middle elements (1) or corresponding parts have been installed a measure (b) interlocked with each other and a distance of margin (a) from each other,

o each slide (2.1) of the transmitter that has been fixed to the middle element (1) and the body (2.2) that has been fixed to the first construction part (A) has been connected with each other with a construction that allows their movement height wise / length wise, characterised in that o it contains a prefabricated element (E) that has been placed in the space between the first construction part (A) and the other construction part (B) which prefabricated element (E) contains:

• a flange (6),

• a refractory ceramic overhang (4) fixed to the flange (6),

• a middle element ring that has been fixed to the flange (6) with the help of the transmitter bodies (2.2) and the slides (2.1),

o the prefabricated element (E) has been fixed permanently to the first construction part (A) and supported either to the slides (2.1) or to the other construction part (B) by the support parts (2.1.1) that are fixed to the to the other construction part (B).

o The joint point (D) is located between the prefabricated element (E) and the other construction part (B).

2. An expansion joint according to the claim 1 characterised in that the power part (8) is a pre-stressed spring.

3. An expansion joint according to the claim 1 or 2 characterised in that the support part (2.1.1) has been fixed to the slide (2.1).

4. An expansion joint according to some of the claims 1 to 3 characterised in that a thin ceramic and elastic fibre plate has been installed between the overhang (4) and the middle elements (1) and between the middle elements (1) and the ceramic lining of the other construction part (B).

5. An expansion joint according to some of the claims 1 to 3 characterised in that the support between the middle elements (1) and the ceramic lining of the other construction part (B) has been arranged so that the surfaces (101.1, 1.5) of the parts in question are able to be ground tight against each other before the support parts (2.1.1) support them into a certain position in relation to each other.

6. An expansion joint according to some of the claims 1 to 5 characterised in that the shape of the cross section of the middle elements (1) is a polygon or a rectangle.

7. An expansion joint according to some of the claims 1 to 6 characterised in that the prefabricated element E that belongs to it is made of more than one parts that go tightly to each other where each of them has a part of the flange (6) that corresponds to its size in the middle element ring with its transmitters and likewise a part of the overhang (4) and the middle elements (1).

8. An expansion joint according to some of the claims 1 to 7 characterised in that the flange (6) is made of either one or more inner and outer parts (6.1, 6.2) or perimeter or either one or more inner and outer parts (6.1, 6.2) or perimeter and consoles.

9. A method to make a 3D expansion joint according to which method: a. the ceramic linings of the first construction part (A) and the other construction part (B) that meet at the joint area are made so that there is a space (107) between them, b. the transmitters are made each of which consists of a slide (2.1) and a body (2.2) that can essentially move only length wise / height wise in relation to each other, characterised in that c. a prefabricated element (E) is made consisting of:

• a flange (6),

• a refractory ceramic overhang (4) fixed to the flange (6),

• a middle element ring that has been fixed to the flange (6) with the help of the transmitter bodies (2.2) and the slides (2.1), d. The prefabricated element (E) is fixed to the first construction part (A) permanently and it is supported to the other construction part (B) using support parts (2.1.1) and the support is maintained by the gravitation and/or power parts (8),

e. The joint point (D) is formed between the prefabricated element (E) and the other construction part (B).

10. A method to make a 3D expansion joint according to which method: a. the ceramic linings of the first construction part (A) and the other construction part (B) that meet at the joint area are made so that there is a space (107) between them, b. an overhang (4) is formed to the ceramic lining of the first construction part (A), c. the ceramic lining of the other construction part is made to end at the surface level (101.1),

d. the transmitters (2) are made each of which consists of a slide (2.1) and a body (2.2) that only can move length wise / height wise in relation to each other, characterised in that e. a middle element ring is made that consists of the middle elements (1) and where at least one transmitter (2) slide (2.1) has been fixed to each middle element (1), f. the middle elements (1) are installed one at a time via outside round the overhang (4) forming a tight circle and so that

i. there is a margin (a) between the overhang and the middle elements, ii. the body (2.2) of every transmitter is fixed to the first construction part A, iii. an expansion space (7) is left between the first construction part (A) and the middle element (1),

iv. the overhang (4) and each middle element (1) are interlocked the measure of (b),

g. between each middle element (1) and the other construction part (B) there will be installed a support with at least one support part (2.1.1) and so that the middle element ring and the other construction part (B) are able to move in relation to each other in the joint point (D) that is between them only into the direction of this plane surface,

h. contact between the support parts (2.1.1) and the other construction part (B) is achieved by the gravitation and/or the power parts (8).