Field of the Invention

The present invention relates to clamping arrangements for tubes and in particular tubes to be mounted within boilers such as those in power stations. The tubes carry water through a heated zone to generate steam.

Background of the Invention

Generally, boiler tubes are arranged as a multiplicity of tubes in a closely spaced parallel array. It is necessary to clamp the tubes to hold them and to support them in the correct position. Tube supports are required at spaced locations along the tubes and in some installations ten or more spaced supports may be required.

US Patent 6,007,029 (Barriger and Wark) describes as prior art a typical industry approach of providing a set of elongate handcuff-like castings to be bolted over a group of about 5 tubes, but with such an arrangement each set of 5 tubes is prone to distortion and misalignment relative to adjacent sets of cuffed tubes. Barriger and Wark propose to deal with the requirement to maintain in alignment a large of number of parallel tubes by providing a coupling adaptor to fit over and interconnect in a clamping arrangement the adjacent end cuff of a typical handcuff set clamping 5 parallel tubes. Thus the coupling adaptor fits over respective semi-circular cuffs portions within which a respective tube is located.

In acknowledging the prior published Barriger and Wark patent, no admission is made that this arrangement is known or used and in particular no admission is made that the arrangement is part of the general knowledge in Australia or elsewhere.

Summary of Invention

In a first aspect, the present invention provides a clamp assembly for clamping a plurality of tubes, the clamp assembly comprising: a plurality of adjacent first clamp elements; a plurality of adjacent second clamp elements; each of the first and second clamp elements having one or more clamping locations, the first and second clamping elements being arranged in use to be in opposing relationship so that respective ones of the clamping locations of the first clamp elements are able to register with respective ones of the clamping locations of the second clamp elements to form a plurality of clamps for clamping respective ones of the tubes; wherein at least one of the first clamp elements includes a plurality of clamping locations two or more of which are in register with the clamping locations of one of the second clamp elements and at least one or more of which is in register with the clamping locations of another of the second clamp elements .

In one form of the clamp assembly, the number of clamping locations in the plurality of first clamping elements equals the number of clamping locations in the plurality of second clamping elements and each of the clamping locations of the plurality of first clamping elements are in register with a clamping location of the plurality of second clamping elements.

In another form, the number of first clamping elements equals the number of second clamping elements. In another form, the number clamping locations in one of the first clamping elements is not the same as the number of clamping locations in at least one other of the first clamping elements. In yet another form, the number of clamping locations in one of the second clamping elements is not the same as the number of clamping locations in at least one other of the second clamping elements .

In one form, the clamping locations include channels formed in the clamping elements, each channel having at least in part an arcuate cross-section for receiving and engaging the exposed periphery of a tube to be clamped. In a further form, the arcuate cross-section of the channels are substantially semi-circular.

In yet another form, side margins of one or more of the clamping locations of at least one of the first and second clamping elements are raked to form guide surfaces for assisting in alignment of the tubes into the channels of the respective clamping locations.

In another aspect, the present invention provides a clamp assembly for clamping a plurality of tubes, the assembly comprising: at least one first clamp element and at least one second clamp element, each of the first and second clamp elements having one or more clamping locations, the first and second clamping elements being arranged in use to be in opposing relationship so that respective ones of the clamping locations of the at least one first clamp elements are able to register with respective ones of the clamping locations of the at least one second clamp element to form a plurality of clamps for clamping respective ones of the tubes; the clamping locations including channels formed in the clamping elements, each channel having at least in part an arcuate cross-section for receiving and engaging the exposed periphery of tube to be clamped, wherein side margins of one or more of the clamping locations of at least one of the first and second clamping elements are raked to form guide surfaces for assisting in alignment of the tubes into the channels of the respective clamping locations.

In one form, the channels of the clamping locations forming a least one clamp of the clamping assembly are curved to accommodate a curved tube .

In another aspect, the present invention provides a clamp assembly for clamping a plurality of tubes, the tubes having at least one tube with a curved portion, the assembly comprising: at least one first clamp element and at least one second clamp element, each of the first and second clamp elements having one or more clamping locations, the first and second clamping elements being arranged in use to be in opposing relationship so that respective ones of the clamping locations of the at least one first clamp element are able to register with respective ones of the clamping locations of the at least one second clamp element to form a plurality of clamps for clamping respective ones of the tubes,- the clamping locations including channels formed in the clamping elements, each channel having at least in part an arcuate cross-section for receiving and engaging the exposed periphery of tube to be clamped, wherein the channels of the clamping locations forming a least one clamp of the clamping assembly are curved to accommodate the curved portion of the at least one tube.

In one form of the clamp assembly, the channels of the clamping locations forming a least one clamp of the clamping assembly are straight to accommodate a straight portion of a tube. Thus in one embodiment, the clamp assembly can clamp curved and straight tubes.

In one form, the clamp elements include intermediate leg portions disposed between at least some of the clamping locations. In a further form, at least one intermediate leg portion of one or more of the first and second clamp elements are arranged to engage with a respective one of the other of the first and second clamp elements. In yet another form, the at least one intermediate leg portion engages in a recess formed in the other of the first or second clamp elements.

In one form of the clamp assembly, the ends of one of the first and second clamp elements have end leg portions adapted to contact with corresponding complementary end leg portion of an adjacent one of the clamp element, wherein the two contacting end leg portions of adjacent clamp elements are adapted to engage with the other of the first and second clamp element intermediate clamping locations of that clamping element. In one form, the end leg portions are half the thickness of the intermediate leg portions.

In one form of the clamp assembly, at least some of the end or intermediate leg portions are adapted to receive fixing elements for securing the opposing clamp elements together. In one form, the fixing elements are received at alternating leg portions of the clamp elements .

In one form, at least some of the end or intermediate leg portions of one of the first and second clamping elements have location projections adapted to be received in the other of the first and second clamp elements. In a further form, the locations projections are located at alternating leg portions of the clamp elements.

In one form, at least some of the leg portions of one or more of the clamping elements include apertures to receive the fixing elements and/or location projections of other clamping elements. In a further form, the location projections are adapted to be welded into the apertures.

In one form, the clamp assembly is for clamping a plurality of boiler tubes.

In another aspect, there is provided a boiler having a plurality of spaced tubes secured by a clamp assembly as claimed in any one of the preceding claims.

Embodiments are directed to new and alternative arrangements for clamping tubes such as boiler tubes and in general terms are implemented by using complementary clamp elements of a handcuff-type configuration with 2 or more clamp elements located end to end across a multiplicity of tubes (other than at the tubes at the side of the array) but the clamp elements on one side of the boiler tubes have their ends located offset relative to the ends of the clamp elements on the other side of the tube, the offset being at least one and preferably two tubes .

This embodiment can be implemented by providing a multiplicity of respective clamp elements which are typically in the form of castings. For example, the castings on one side of a tube array may include clamping locations to accommodate 7 tubes, 7 tubes and 5 tubes respectively for a total of 19 whereas the castings arranged on the opposite side accommodate 5 tubes, 7 tubes and 7 tubes .

Embodiments may utilise nuts and bolts for example at alternate tube gaps to secure together the respective clamp sets. By implementing the clamp elements as castings, the castings could be of the same form but just differing in length but in embodiments the castings for one side of the boiler tubes have projections or spigots and the castings for the other side have apertures to receive the spigots. This embodiment permits the spigots to be welded at every other tube and the bolts are located at the intervening locations.

An aspect of the invention may be defined as consisting in a method of clamping a multiplicity of tubes arranged in first and second sets and comprising using first and second clamp elements each having clamping locations disposed on respective sides of the tubes, each clamping location having a multiplicity of arcuate recesses for receiving and engaging the exposed periphery of tubes and integral leg portions arranged to extend generally between adjacent tubes to maintain them in spaced relationship, at least some of the leg portions of respective clamps being adapted to align and receive fixing means for securing the clamps together around the tubes and wherein at least one tube of the first set and adjacent the second set on a first side is adapted to be contacted by a clamping location of the first clamping element and adapted to be contacted by a clamping location of the second claming element on a second side, the respective ends of the first and second clamp elements having complementary leg portions adapted to be directed between said at least one tube and the next tube and to cooperate with a leg portion from a clamp on the other side of the tubes.

Alternatively, in a further aspect of the invention can be defined as consisting in an arrangement for supporting tubes, the tubes comprising at least a first set defined as tubes a, b...l, m and a second set defined as n, O...X, y, the tubes being arranged to be clamped and supported in spaced relationship to one another by first and second clamping elements forming a cooperating clamping couple and third and fourth clamping elements forming a second clamping couple, each of the clamping elements having arcuate cavities for receiving and engaging a surface of a tube with respective leg portion of the clamp projecting for engaging between and spacing adjacent tubes, at least some of the leg portions having means for accommodating fixing means whereby that the clamps when installed fix together the structure, the arrangement being such that at least tube o from the second set is clamped between an end portion of the first clamping element and a portion of the fourth clamping element and tube n is clamped between an end portion of the fourth clamping element and the portion of the first clamping element whereby the leg portions of the end of the second and fourth clamping elements project between tube m and tube n and the leg portions of the first and second clamping elements project between tubes 1 and m or another pair of tubes further along the first set from tube m towards the tube a. In an another aspect, the present invention may be defined in consisting in a clamp apparatus for clamping a multiplicity of tubes, the clamp apparatus having first and second clamp sets each shaped to be installed on respective opposite sides of the tubes and to contact the tubes in supporting engagement, and to be clamped to each other by fixing elements, the first clamp set including a major clamping element to engage a group N in number adjacent tubes and a minor clamping element to engage of group (N-2) in number of adjacent tubes, the second clamp set including a minor clamping element to engage (N-2) in number adjacent tubes and a major clamping element to engage N in number adjacent tubes, the clamping elements of the second set having apertures therethrough to receive at alternate positions between adjacent tubes location projections from the first clamp set and fixing elements, the first clamp set accommodating the fixing elements at corresponding alternating positions between tubes and providing at the other alternating positions between tubes the location projections, each end of each clamping element being dimensional to locate with the end of another clamping element in the set, and at each junction region there is a 2 tube overlap between the co-operating clamping- elements of the first set and the second set.

Brief description of the Figures

For illustrative purposes embodiments of the invention will be described with reference to the accompanying drawings:

Figure 1 is an isometric view of an embodiment for clamping 19 parallel boiler tubes;

Figure 2 is a plan view of the embodiment of Figure

1; Figure 3 is a sectional side elevation taken along the line A-A of Figure 2; Figure 4 is an inverted plan view of the embodiment of Figure 1;

Figure 5 is an enlarged view taken along the section line B-B of Figure 4 ; Figure 6 is a sectional side view taken along the line C-C of Figure 4;

Figure 7 is a bottom view of an enlarged scale of the central portion of the structure shown in Figure 5 ;

Figure 8 is an exploded perspective view of the embodiment of Figure 1 ; and

Figure 9 is an exploded view of the embodiment of Figure 1.

Figure 10 is an isometric view of another embodiment of a clamp assembly. Figure 11 is a side view of the assembly in Figure 10 with one clamp element sectioned, and a plurality of tubes disposed in the clamping locations.

Figure 12 is a sectional side view of the sectioned clamp element in Figure 11. Figure 13 is an isometric view of another embodiment of a clamp assembly with a plurality of clamped tubes.

Figure 14 is a top plan view of the embodiment in Figure 13.

Figure 15 is a side view of the assembly in Figure 13, with the tubes sectioned.

Figure 16 is an isometric view of a clamp element of the clamp assembly in Figure 13.

Figure 17 is a top plan view of the clamp element in Figure 16.

Detailed Description of the Drawings

A first embodiment will now be described with reference to Figures 1 to 9. Figure 1 shows a plurality of boiler tubes 10. In this embodiment, the boiler tubes are provided to be secured between a plurality of first clamp elements 12 and a plurality of second clamp elements 14. Each of the clamp elements 12, 14 has clamping locations 7, arranged in an opposing relationship to the clamping locations on the other respective clamp element 12, 14 to form a plurality of clamps 9 for clamping the tubes 10.

The plurality of first clamp elements 12 comprises an end first clamp element 16, a middle first clamp element 17 and an end first clamp element 18. As illustrated in Figure 3, the first clamp elements 16 and 17 each have seven clamping locations 7 and end first clamp element 18 has five clamping locations.

As better shown in Figure 3, the plurality of second clamp elements 14 comprises an end second clamp element 20, a centre second clamp element 21 and an end second clamp element 22. End second clamp element 20 has five clamping locations 7 and the remaining second clamp elements 21 and 22 each have seven clamping locations 7.

The number of clamping locations 7 in the plurality of first clamp elements is equal to the number of clamping locations in the second clamp elements, to form the plurality of clamps 9. The elements 12 and 15 are configured as such that there is a two tube overlap at each overlap location between the middle clamp elements 17, 21 and the end elements 16, 18, 20, 22.

Figure 1 shows an installed location of the clamp elements in position and secured by bolts 24 and nuts 25. The bolts pass through aligned apertures in the clamps at every other position between the tubes 10. Each clamp 9 has a body portion 26 as shown in Figure 5 extending the width of the clamp i.e. parallel to the axis of the tubes and extending between the tubes so as to confront the opposite clamp and define substantially half circular cross-sectional shape concavities for accommodating a half of the tube. Leg portions 28 are provided in the clamp elements such as at location 28 shown in Figure 6. The first clamp element in this embodiment in a leg portion has a projecting spigot 30 configured to pass into a complimentary aperture through the second clamp element. This spigot 30 is weldable.

At the end of each clamp there is a half thickness end leg portion 32 which in this embodiment also has in the central region for the first clamp element, a projecting half spigot 34 so that this half spigot and the half spigot of the adjacent abutting first clamp element passes into the aperture in the second clamp element. Each second clamp has an aperture of half a spigot at its end wall .

Figure 7 shows a bottom view on an enlarged scale. Centrally located is a bolt secured by a nut 25 over a washer 38 and to the right hand side is seen the junction between second clamps elements 20 and 21 with respective half apertures for accommodating a projecting full spigot 30 from first clamp element. At the left hand end is seen the tips of half spigots 34 projecting from the respective ends of the first clamp elements.

Figures 10 to 12 illustrate another embodiment of the clamp assembly 101. The clamp assembly 101 has first clamp elements 103 and second clamp elements 105, each having a plurality of clamping locations 107. The first and second clamping elements 103 105 are arranged in an opposing relationship, such that opposing respective clamping locations 107 form a plurality of clamps 109 for clamping respective tubes 111. The clamping locations 107 comprise of a channel 113 having an arcuate cross-section, and raked side margins 115.

Referring to Figure 11, the clamp elements 103, 105 each have a plurality of intermediate leg portions 117 disposed between the clamping locations 107 and end leg portions 118 at the ends of the clamp elements 103, 105. When assembled, the leg portions 117, 118 of each clamp element 103, 105 extends towards the leg portions 117, 118 of the opposing clamp elements 103, 105.

Alternating intermediate leg portions 117, of the first clamp element 103, are provided with location projections 119, which are received into apertures 121 of the second clamp elements 105. The end leg portion 118 is provided with an end projection 123, which is half the width of the location projections 119.

The remaining alternating leg portions 117 of the first clamp element 103, and apertures 121 of the second clamp element 105, are adapted to receive fixing elements 125 for securing the opposing clamp elements together.

To assemble the clamp assembly 101, the clamping locations 107 of opposing clamp elements 103, 105 are disposed on opposite sides of the tubes 111. The location projections 119 are aligned with respective apertures 121, and the clamp elements 103, 105 are drawn together, with the location projections 119 assisting in alignment of the clamp elements 103, 105 relative to each other. At the same time, the side margins 115 of the clamping locations 107 guide respective tubes 111 into the channels 115. Once the tubes 111 are clamped by respective clamping locations 107, the clamp elements 103, 105 may be secured by fixing elements 125. The clamp elements 104, 105 may be further secured by welding the projections 119, 123 into the apertures 121.

Figures 13 to 17 illustrate another embodiment of the clamp assembly 201. The clamp assembly 201 has a first clamp element 203 and a second clamp element 205, each having a plurality of clamping locations 207 for receiving a portion of a tube 211.

As illustrated in Figures 13 and 14, the tubes 211 comprise of straight portions 212, and curved portions 214 that are received in clamping locations 207. Accordingly the clamping locations 207 comprise of channels of different dimensions.

Referring to Figures 16 and 17, straight channels 213 are straight to accommodate straight portions 212 of the tubes 211. In addition, curved channels 216 are curved to accommodate the curved portions 214 of the tubes 211. Centrelines 251 and 253 represent the centrelines of the respective tube portions to be clamped.

Advantageously, the clamp assembly 201 allows clamping of a plurality of tube portions that may be curved, straight, or a combination of both.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.