A DEVICE FOR THE REMOVAL OF GAS AND PARTICLES FORMED DURING WELDING AND CUTTING JOBS

Abstract: There is described an arrangement for removing gas, smoke, solid particles and the like in connection with welding and/or cutting burning. An embodiment of the invention is an arrangement which in the main consists of two parts which can be easily latched together, namely an outer housing and an inner part, in which the outer housing comprises means for the suction of air-borne pollutants, and also means for cooling both the outer housing and the inner part, and where the inner part is adapted to reduce the energy of the spark particles which are formed.

Description: A DEVICE FOR THE REMOVAL OF GAS AND PARTICLES FORMED DURING WELDING AND CUTTING JOBS The present invention relates to an arrangement for removing gas, smoke, solid particles, such as sparks and the like, in connection with welding and/or cutting burning . On conducting different types of welding work gases and smoke are formed which are harmful to the person who performs the working operation. Particularly on the welding of dissimilar metal alloys gases will be formed which are dangerous to the health. In addition gases and smoke which are formed will reduce visibility in the welding area . On cutting metal various types of cutting machines and cutting burners are used. Also in these working processes gases and smoke are formed which are harmful, in addition to there being formed large quantities of sparks, which are small, very warm particles. Microparticles are also formed which are too small to be seen, and these are transported by air currents into the body of the worker where they cause great harm. It is therefore necessary to remove these gases and particles in an effective manner. Various methods have been tested. For example the general circulation in the building can be increased. However this creates other problems, such as noise, drafts and high energy consumption. Another solution is to use point suction which is mounted above the welding/cutting point and which has as an object to suck in the gases/particles which are formed. However the problem is not solved satisfactorily since the gases/particles are sucked from the working area and upwards to the point suction, that is to say past the person who performs the work. NO-63259 describes a work table which is used in welding work and the like, where the board per se is equipped with openings, and where the gases are sucked downwards through the openings by a suction flow which is arranged on the under side of the board. NO-143835 describes a broken through work board for cutting operations where there is arranged beneath the board a suction arrangement . Furthermore the suction box is provided with means for the reduction of the speed of jets/sparks, and means for cooling. The solutions referred to are both designed for permanent mounting in for example plant halls. Both of the solutions are large and complicated constructions, and cannot be easily moved from one working location to another. The present invention aims therefore to reduce or solve the afore-mentioned problems which are connected with welding/cutting. More specifically this involves producing an effective system for removing gases/ particles, together with a system for the reduction of the speed of sparks, and the cooling of these, and furthermore that the system is constructed with a low net weight and small dimensions, so that the arrangement is mobile and can be moved in a simple manner from one working location to another. An embodiment of the present invention is characterised by the arrangement comprising in the main two parts, which can be easily latched together, namely an outer housing and an inner part, wherein the outer housing comprises means for drawing off air-borne pollutants, together with means for cooling both the outer housing and the inner part, and where the inner part is adapted to reduce the energy of the spark particles which are formed. Another embodiment is characterised by the arrangement being detachably fastened to the material which is to be welded/cut, and that the welding/cutting takes place within said arrangement, the arrangement being provided with openings, for conducting through equipment for welding and cutting, together with transparent sheets which are positioned in the arrangement so that the working operation can be controlled/performed from the outside of the arrangement. The present invention will be further explained with reference to the following claims and Figures, wherein: Fig. 1 shows in perspective an example of an arrangement according to the invention, illustrated obliquely from above. Fig . 2 shows the arrangement according to Fig . 1 and its inner part seen in perspective from the side. Fig. 3 shows the arrangement according to Fig. 1 - 2 and its housing portion seen in perspective from above. Fig. 4 shows a section of a cross-section of an embodiment according to Figures 1 - 3 where the arrangement is provided with ducts for conducting cooling medium. Fig. 5 shows in a section of a cross-section an another embodiment of the arrangement where the cooling medium is conducted in a set of double walls. Fig. 6 shows with arrows the principle as to how sparks are led through the arrangement 10. Fig. 7 shows an embodiment of the arrangement which is especially applicable for welding/ cutting burning of materials with curves. Fig. 8 shows an arrangement approximately the same as that in Fig. 7 in a section of a cross-section, where the arrangement is positioned on the outside of a pipe. Fig. 9 A - D shows how an opening surrounds an object of varying size in that there are arranged spring-loaded lips in the opening. Fig. 10 shows another embodiment of the invention, where the arrangement is equipped with a handle. Fig. 1 shows an arrangement 10 for receiving sparks, solid particles, gases and smoke in connection with weld- ing and cutting operations of dissimilar materials. The arrangement 10 can be used on all types of material which emit gases and/or particles, but is preferably designed for various metals/metal alloys. The arrangement is composed of two parts, namely a housing portion 11 and an inner part 12. The housing portion 11 is shown in Fig. 3 and the inner part is shown in Fig. 2. In the concrete embodiment which is indicated in Figs. 1 - 4 the housing portion 11 is formed of a bottom part 13 and four wall portions 14, which stretch substantially vertically relative to the horizontal bottom part 13. The wall portions 14 are arranged slightly sloping outwards, that is to say that the opening has a larger periphery than the bottom portion 13. The uppermost region of the wall portions 14, namely the portions 14a are bowed so that they extend approximately at right angles relative to the bottom portion 13. The housing portion 11 has a design and dimensions which are adapted for the reception of the inner part 12. On one or more of the walls 14 there are arranged attachments 15 for the reception and positioning of the inner part 12, so that this can be latched in place in the housing portion 11 since outer sides of the inner part 12 are equipped with oppositely acting fastening means 15a. The positioning of the inner part 12 in the housing portion 11 sees to contact between the two parts, at least in the region uppermost in the wall portions 14a of the housing portion 11. In order to make Fig. 4 more clear the portions 14a and 20a are indicated at a certain distance. The housing portion 11 is equipped with a number of fastening means 16 for fastening to a suitable work location. This can be on the under side of for example a metal plate which is in the course of being finished, it being either welding or cutting. In the concrete embodiment which is shown in Fig. 1 magnets are indicated as fastening means 16. On outer walls 14 of the housing portion 11 a set of fastening ears 16a are arranged. To the fastening ears 16a magnets 16b are fastened via adjustable fastening screws 16c. Other fastening means 16 can also be employed, such as suctions cups or spot welds. In the housing portion 11, through the bottom part 13, an exit 17 is arranged. To this exit 17 is mounted, via a rapid coupling, a vent so that gases and smoke are effectively sucked out of the arrangement 10. In an embodiment there are used means (not indicated in the Figures) , such as a packing attached to the uppermost edge of the wall portion 14a, in order to ensure a sealing joint between the arrangement 10 and for example the metal plate which is in the course of being finished. This ensures that the vent functions effectively, and approximately all the gas and smoke which is formed will be sucked into the vent via the arrangement 10. The housing portion 11 is also equipped with cooling means 18. In the concrete embodiment which is illustrated in Figs. 1, 3 and 4 a longitudinal angle section is fastened to the outside of outer walls 14 of the housing portion 11. This involves ducts 18 being formed. These ducts can also be formed by triangular sections, U- sections and pipes and the like. The ducts 18 are arranged with an entrance portion 18a near the bottom 13 of the housing portion 11. Through these ducts 18 there flows a cooling fluid, for example cold water, liquid nitrogen and the like. The ducts 18 stretch further upwards along one or more walls 14, and as shown in Figures 1, 2 and 4 they surround the periphery of the housing portion 11 in a region in the vicinity of the wall portions 14a. In this manner the housing portion 11 is cooled, and by virtue of the direct contact with the inner part 12, this is also cooled. In individual regions, preferably uppermost on the housing portion 11, the ducts 18 can be arranged with small openings 18a so that cooling fluid, such as water escapes from the ducts 18. Alternatively, and not indicated further in the Figures, the ducts 18 are provided with an outlet portion which the water is led out through. Thus fresh cold water will constantly come into the arrangement 10, receive some heat from the arrangement 10, and thereafter be removed. It is preferred, but not the only solution, that the flow through of water takes place upwards, that is to say against the force of gravity. In a concrete embodiment which is illustrated in Fig. 5 housing portion 11' of the arrangement 10' is provided with a set of double walls 14b' . This leads to water circulating between the double walls 14b' over the whole external upper surface of the housing portion 11' . This gives an effective cooling of the housing portion 11', and via this also the inner part 12'. There are arranged, in a corresponding manner as explained above, an entrance portion 18a' , preferably in the bottom of the housing portion 11', and an exit portion 18', preferably in the top of the housing portion 11'. The entrance and exit portions 18a' , 18b' are equipped with rapid couplings not indicated further. The housing portion 11,11' can further be equipped with means, such as a handle 19, so that it can be easily transported, and also positioned to for example the metal plate which is to be finished. Fig. 2 shows the inner part 12. In the concrete embodiment which is illustrated this is designed as two pyramids, namely a larger pyramid 20 with the apex directed downwards and a smaller pyramid 21 with the apex directed upwards. The pyramid 20 is open at both ends, that it to say pyramid stump shaped. The widest portion of the pyramid 20, which faces upwards, has a periphery which is somewhat less than the opening of the housing portion 11 so that the inner part 12 is received in the housing portion simultaneously with contact being established between the two portions 11,12. The pyramid 20 is therefore constructed with substantially vertical walls 20a, together with a wall portion 20b with sloping walls. As mentioned the apex of the pyramid 20 is open at the top so that an opening 20c is formed. Through this opening 20c passes then the smaller pyramid 21, with the apex upwards, a distance into the pyramid 20. There are still openings between the two pyramids 20,21 on all sides. The lowermost pyramid 21 is fastened to a saucer-shaped portion 22. In a concrete embodiment the transition between the pyramid 21 and the saucer-shaped portion 22 is rounded as is shown in Fig. 4, in order to ensure effective deflection of sparks. Fastening means 23 are arranged in order to position the two pyramids 20,21 relative to each other. Fig. 4 and Fig. 5 show in a section of a cross-section how the two pyramids 20,21 can be positioned relative to each other. The pyramids can also be designed with fewer or more than four walls, or for example have a conical form. That which is important is that the walls are obliquely disposed relative to the flow of sparks. On cutting burning sparks are formed. If they are not shielded these can kick about 4 - 5 metres. The object of the specific design of the pyramids 20,21 is to be able to absorb these sparks, and also to reduce their speed and cool them. This is done by the sparks not colliding at right angles against a surface, but instead striking the surface obliquely so that the direction is changed, and the sparks are deflected. Thus the speed will be reduced at the same time as only a smaller part of the energy/heat of the sparks is transferred to the inner part 12. Fig. 6 shows with arrows how the current of sparks will move in the arrangement 10. First the spark flow strikes the inside of the pyramid 20 where the direction is deflected. Thereafter the sparks will strike the saucer portion 22, be deflected and the flow of sparks is led further up co LO t to μ» μ- LΠ O Lπ o LΠ o LΠ J rt tr P- 3 ^ φ 0 ) Φ rf J -3 rt -3 Φ Φ PJ Φ Pi 3 rf 03 rf O tr μ 1 Φ Hi 0 0 li 0 3 Hi rt Φ CQ X ft μ- 0J tr Pi 3 a> φ •8 tr 0 φ 0 Hi 3 J CQ ff μ- μ- tr J 3 Φ φ LQ CQ TJ TJ ^ 0 0 ii r-h ii PJ rt 3 P-. μ- μ- μ- 0 Pi 03 3 03 to μ- μ* o 3 μ- • øJ 3 ØJ tn Pi ri Φ ri rf P-. Φ tr μ- Φ ø j rt 3 tr μ- φ Φ 3 rf 03 Φ Ω μ- ri 3 Pi • ri Φ ϋ Φ 0 3 r-h rt In contrast to the embodiments shown in Fig. 1 - 6 the arrangement 10'' is positioned on the upper side/ outside of the material which is finished, that is to say above the work area, in such a manner that the welding/ cutting takes place within the arrangement 10'' per se . Fig . 7 shows an embodiment of such an arrangement 10' ' . This can be made of a plate which is bent so that wall portion(s) 14'', and roof portion(s) 13'' are formed. The wall portion(s) 14'' and the roof portion(s) 13'' can be dissimilarly disposed obliquely as is shown in Fig. 7. Two opposite walls 14a' ' are detachable from wall/roof portions 14 '',13'' so that they can be readily replaced. The wall portions 14a' ' are formed thus with openings 14b'' of various dimensions/diameters, that is to say with different curvatures so that they surround pipes of dissimilar diameter. There can also be installed wall portions 14a' ' so that the whole opening 14b' ' is covered if the arrangement 10'' is to be used on a flat base. The wall/roof portion (s) 14 '',13'' are equipped with means 14c'' in order to form rapid fastenings/latch engagements with the wall portions 14a' ' . The arrangement 10'' comprises further one or more flexible openings 13a' ' in the wall or roof portions 13' ' , 14 ' ' , 14a' ' so that equipment for cutting burning/ welding can be guided through. Such a flexible opening 13a' ' can be formed of a set of movable lips 13b' ' as indicated in Fig. 9A - D. These lips 13b'' will envelop equipment of dissimilar form, and also provide for tight enveloping when the equipment moves . The arrangement 10'' is further equipped with a number of transparent panels 30'', positioned and adapted so that the work area is easily visible for the worker. In Fig. 7 two such transparent panels are indicated, where the one is the most suitable in connection with welding, and the other for cutting. Furthermore the arrangement 10'' is provided with coupling points for respectively sub-atmospheric pressures 31'' and super-atmospheric pressures 32''. The super- atmospheric pressure is used in order to prevent the admission of explosive gases, and in order to get a better through flow of new air, while the sub-atmospheric pressure removes smoke, gases and particles. Both the sub- atmospheric pressure and the super-atmospheric pressure will reduce the temperature in the work area. The arrangement 10'' thus ensures that a closed off and approximately gas-tight space is formed over the welding/cutting operation. The arrangement 10'' is extremely flexible and on replacement of the wall portions 14a' ' can be used for all grades of curving, such as pipes of any dimension, as well as flat surfaces. The arrangement 10'' is equipped with a set of fastening means 16'' (not indicated further in the Figure) for fastening of the arrangement 10'' to the base. As is evident from Fig. 10 the arrangement 10''' can be equipped with a number of handles 35''' adapted so that the arrangement 10''' can be easily moved in dissimilar directions, for example alongside a pipe. This is particularly favourable for example if the equipment for welding/cutting is permanently mounted to the arrangement 10'', 10''', since the handles 35''' result in the equipment being easily movable from position to position, that is to say that the arrangement 10' ',10''' is moved gradually as the work progresses forward. In Fig. 10 is seen an inlet pipe 36''' which conducts in acetylene and oxygen in connection with welding. The welding equipment is mounted on the inside of the arrangement 10'''. In a corresponding manner as for the arrangement 10,10' which is indicated in Figs. 1 - 6, the arrangement 10 '',10''' in Fig. 7,8 and 10 is provided with ducts or double walls for conducting cooling medium. As is evident from Fig. 8 the interior of the pipe which is finished will function as a spark catcher, as the pyramids 20,21 function in the arrangement 10,10'. The object of the invention is to obtain a simple, compact and small spark and smoke catcher, which hence is mobile, and which effectively removes gases and smoke, and also absorbs gases and solid particles which are formed by welding and cutting burning.

Claims: Patent Claims 1. Arrangement (10,10') for removing gas, smoke, solid particles, such as sparks, in connection with welding and/or cutting burning, comprising a suction unit for receiving gases and particles, an energy reducing means for reducing the speed and the energy of spark particles, characterised in that the arrangement (10,10') comprises a housing part in which the energy reducing means is arranged, and also that it comprises the suction unit and an opening for receiving welding gases and particles, and that the arrangement is adapted to be positioned in connection with, and with its open end facing towards, the work piece, that is to say on the opposite side of the work piece relative to the welding and/or cutting burning flame. 2. Arrangement in accordance with claim 1, characterised in that the arrangement consists of two jointable parts, namely an outer housing (11,11') comprising the suction means and cooling means, and an inner part (12,12') designed with a number of obliquely disposed wall portions (20b, 21b, 20b' , 21b' ) which are adapted to reduce the energy of the particles which are formed during the welding and/or cutting burning operation, and that the outer housing and the inner part are in contact with each other so that an effective heat exchange between the two parts occurs. 3. Arrangement in accordance with claim 2 , characterised in that the inner part (12,12') comprises two oppositely directed pyramid-shaped elements (20,20', 21,21'), that is to say a first pyramid (20,20') which faces downwards, and a second pyramid (21,21') which faces upwards, where the top of the first pyramid (20,20') is removed so that an opening (20c, 20c') which the second pyramid (21,21') is positioned in is formed in such a manner that openings are formed on all edges between the two pyramids (20, 20', 21, 21'). 4. Arrangement in accordance with claim 3 , characterised in that the inner part (11,11') further comprises a saucer-shaped portion (22,22') which forms a base for the second pyramid (21,21'), where the saucer (22,22') stretches beyond the base of the second pyramid (21,21'), and where the saucer (22,22') has an upwardly facing annular edge (22a, 22a'). 5. Arrangement in accordance with claim 4, characterised in that the outer part (11,11') comprises means (18,18') for cooling and that the outer portion in at least a portion (14a, 14a') is in contact with the inner portion (12,12') so that heat is transferred from the inner part (12.12') to the outer part (11,11'). 6. Arrangement in accordance with claim 5, characterised in that the outer part is sealingly fastened via fastening means (16,16') to the material which is in the course of being finished so that the suction flow effectively ensures that approximately all gases, solid particles and the like are guided via the inner part (12) and out through the exit portions (17) of the outer part (11) • 7. Arrangement in accordance with one of the claims 1 - 6, characterised in that the arrangement (10,10''') further comprises a unit (10'') which is detachably jointed to the side of the material which is finished, that is to say is welded/cut, the unit being provided with openings (13 ' ' , 13' ' ' ) in order to guide through equipment for welding and cutting, and transparent surfaces (30'', 30''') adapted so that the working operation which is carried out in a space which is defined by the unit (10'') and the material which is finished can be controlled and guided from the outside of the arrangement (10' ',10''') . 8. Arrangement in accordance with claim 7, characterised in that the unit (10'') comprises at least two opposite detachable replaceable wall portions (14a'') so that the unit can be adapted to materials having different curvatures. 9. Arrangement in accordance with claim 8, characterised in that it comprises ducts (32'', 32''', 33 '',33''') for imposing super-atmospheric and sub- atmospheric pressures . 10. Arrangement in accordance with one of the claims 8 - 9, characterised in that it comprises ducts for conducting cooling fluid. 11. Arrangement in accordance with one of the claims 1 - 10, characterised in that the arrangement (10 , 10 ' , 10 ' ' , 10 ' ' ' ) is easily movable from one work location to another, that is to say that constructionally it is relatively small, and that it is equipped with fastening means (16,16') so that it can be easily fastened to and detached from a base .

Inventors: VAAGE REIDAR, WIIK VIDAR, VAAGE, REIDAR, WIIK, VIDAR
Applicants: VAAGE REIDAR, WIIK VIDAR, VAAGE, REIDAR, WIIK, VIDAR
Application year: 1998
Main classification: B08B15
IPC codes: B08B15