NZ240092A

NZ240092A - Reinforcing and repairing pipe journals, joints and bends subjected to

Info

Publication number: NZ240092A
Application number: NZ24009291A
Authority: NZ
Inventors: Knut H Johansen; Oyvind Larsen; Hans H Schelderup
Original assignee: Elkem As
Priority date: 1991-10-04
Filing date: 1991-10-04
Publication date: 1994-02-25

Description

<div id="description" class="application article clearfix"> 240 092 Priority D?te{s): . S Compete Spec.lie at: on Fi'.ad: . . Class: • f- ^USSifciS .W ' ' . 2 5 FEB 1994 Publication Dsts: P.O. Jx-rn:.1, Mo: .... i^TlTI N.Z. PATENT OFFICE -4 OCT 1991 RECEIVED Patents Form No. 5 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION METHOD FOR REINFORCING AND REPAIRING EQUIPMENT DETAILS AND COMPONENTS SUBJECTED TO HEAVY ABRATIONAL WEAR WE, ELKEM A/S, a company under the laws of Norway, of Nydalsveien 28, 0483 Oslo 4, NORWAY 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: 2 2 A 0 0 9 2 The present invention relates to a method for reinforcing and repairing equipment parts and components subjected to heavy abrational wear during use. Abrational wear is a frequent and costly problem in a variety of industries such as 5 mining industry, mineral processing and transportation industry, coal fired power plants and oil and gas production installations. In all these industries a common problem is the abrational wear caused by solid particles on equipment used for handling and transportation of such solid particles. 10 The particles, may be transported or handled in dry form for example by pneumatic transport or in a liquid slurry form. Normally some parts of such transportation and handling equipment are more subjected to abrational wear than the rest of the equipment. One typical example is bends in transportation lines for particles. Whereas the greater part of the transportation line can have a lifetime of up to many years, bends 15 in the transportation lines may have a lifetime of just a few weeks. Such transportation lines and other handling equipment must therefore very often be stopped for maintenance, which normally includes replacement of bends and other critical components. Thus the maintenance costs are very high and production is lost due to the high downtime of the equipment. This problem has frequently been tried to be 20 solved by replacing critical parts made from standard material with parts made from more wear resistant materials. This does, of course, somewhat increase the lifetime of the critical parts, but unfortunately the costs for wear resistant materials are very high so the overall costs are not significantly reduced. 25 It is therefore a need for a simple and low cost method for reinforcing or repairing critical parts which are subjected to high abrational wear. It is an object of the present invention to provide a Simple low cost method for reinforcing and repairing equipment parts and components which are subjected to 30 abrational wear during use. Accordingly, the present invention relates to a method for reinforcing or repairing equipment parts and components subjected to abrasional wear, being junctions, joints and bends, wherein a casing is affixed only to that part of the \ t \ i \ » Ik 0 0 9 2 junction, joint and bend subjected to abrasional wear, and that a wear resistant concrete material is cast into the spacing between the casing and the surface of the equipment part or component. According to a preferred embodiment of the method according to the present invention 5 a ceramic wear resistant material having one surface corresponding to the surface to be repaired or reinforced is temporarily affixed to the equipment part or the component, whereafter a concrete material is filled into a cavity between the ceramic material and an enclosing casing. 10 The method of the present invention is particularly suitable for reinforcing or repairing parts of transponation lines such as bends and other parts which are subjected to abrational wear by particles transported in the transportation lines. If the places subjected to heavy abrational wear can be localized during the design of a 15 transportation line or any other equipment, these places can already during construction of the equipment be reinforced by the method of the present invention. The lifetime of the critical parts can thereby from the very beginning be strongly increased. In other cases spots or areas on equipment parts or components subjected to high 20 abrational wear can be detected after having been in use for some time and can then be repaired by the method according to the present invention. In many cases equipment parts and components which normally would have been considered to be completely worn out can be repaired by the method of the present invention. 25 The method according to the present invention will now be further described by way of examples and with reference to the accompanying drawings, wherein, Figure 1 shows an axial cut through a pipe bend repaired 6r reinforced according to the method of the present invention, 30 Figure 2 shows a cut taken along line I -1 of figure 1, Figure 3 shows an axial cut through a pipe bend repaired or reinforced according to another embodiment of the present invention, and wherein, 4 240 0 Figure 4 shows a cut taken along line II - II of figure 3. In the embodiment shown on figures 1 and 2 there is shown a pipe bend 1 made from 5 steel. The pipe bend can for example be a part of a transportation line for transporting particles causing abrational wear. After having been used for some time a part of the wall 2 in the pipe bend 1 will be worn and perforated as shown by reference numeral 3. This worn out bend is now repaired by the method according to the present invention. 10 The outside surface of the area of the wall 2 to be repaired is, if necessary, sandblasted and cleaned. A casing 4 made from steel plates is welded to the outside of the area of the pipe bend 1 to be repaired. The casing 4 is provided with an opening 5 at its upper end. A wear resistant concrete mixture 6 is made and cast through the opening 5 in the 15 casing 4 and into the cavity between the wall 2 of the pipe bend 1 and the casing 4. If necessary vibration is used to secure a voidfree concrete material. After a few hours hardening time in order for the concrete 6 to reach some strength, the pipe bend 1 can again be put into operation. 20 In most cases this method of repairing can be done without demounting the parts to be repaired. The only space needed is the space necessary to bring the casing 4 in place. It should be appreciated that if the pipe bend 1 has big holes it can be necessary to cover the holes with a thin steel plate 7 or the like in order to prevent the concrete to 25 flow through such holes and into the interior of the pipe bend 1. The embodiment shown on figures 3 and 4 only differs from the embodiment of figures 1 and 2 in that a plate 8 of ceramic abration resistant material is placed in contact with the worn out area of the pipe bend 1 before the concrete 6 is cast into the casing 30 4. In order to keep the ceramic plate 8 in place before the casing 4 is put in place and the concrete 6 is supplied, the ceramic plate 8 is affixed to the wall 2 of the pipe bend 1 by means of for example glue or some other affixing means. 5 240 092 By the method according to this embodyment it is obtained a surprisingly high abrational wear protection at a very low cost, as the ceramic material is only used in the spesific areas subjected to high abrational wear. 5 EXAMPLE 1 In a transport line for dry nepheline syenite particles the bends had to be replaced about every 6 months due to perforations caused by the abrational wear caused by the nepheline syenite particles. The transport line was made from steel pipes of 60 mm 10 diameter and comprised two bends of radius 500 and 580 mm, The two bends were repaired using the method of the present invention in the way desribed above in connection with figures 1 and 2. A super concrete with SiC filler was cast into a casing made from 3 mm steel plates. Two years after the repair there have 15 been no signs of perforations or any abnormalities in the bends repaired according to the method of the present invention. Thus the lifetime of the bends have been increased at least four times. EXAMPLE 2 20 The method according to the present invention was used for repairing a bend on a vacuum cleaning line used for collecting dust from a latheing operation in production of large carbon electrodes. A total of 5 bends made from steel pipes having a diameter of 60 mm and a wall thickness of 3 mm were repaired according to the method of the 25 present invention. The bend radius were up to 1200 mm. The installed repair length were up to 800 mm. Normal operation life of the steel bends was typically 2 weeks. The corresponding operation life of the bends after having been repaired according to the method of the present invention using a concrete containing SiC as a filler cast into a casing made from steel plates of 3 mm thickness drastically increased. Thus the 30 bends repaired in this way have now been in operation for 5 months giving an increase in lifetime of at least 10 times. EXAMPLE 3 240 092 Some of the bends in the vacuum cleaning line described in example 2 were repaired in the same way as in example 2 except that a siliconized silicon carbide wear plate of 8 mm thickness were arranged in contact with the wall of the bend before the casing was mounted and the concrete was cast into the casing. These bends have now been in operation for six months and so far very little wear has been observed. It is therefore expected that the bends will have a lifetime between 1 and 2 years. </div>

Claims

<div id="claims" class="application article clearfix printTableText"> 7 24 00 92 WHAT WE CLAIM IS: - 1. A method for reinforcing or repairing equipment parts and components subjected to abrasional wear, being junctions, joints and bends, wherein a casing is affixed only to that part of the junction, joint and bend subjected to abrasional wear, and that a wear resistant concrete material is cast into the spacing between the casing and the surface of the equipment part or component. A method according to claim 1, characterizedin that a plate of ceramic wear resistant material having one surface corresponding to the surface to be repaired, is affixed to the equipment part or component before the casing is put in place and the concrete is cast. A method according to claim 1, characterized in that a thin steel sheet is affixed to the surface to be repaired before the casing is put in place and the concrete is cast. </div>