10/04 COVER 1 zaida

We use cookies to personalise content and ads, to provide social media features and to analyse traffic. We share info about use of our site with social media, ads and analytics partners. By continuing to browse you are agreeing to use of cookies. See details or close this message.

Page

100%

Specifications	10/04 COVER 1 zaida
Business section

WELDING RESEARCH -S287WELDING JOURNAL ature, the iron material from the plate re- acts with the excess oxygen provided by the

Specifications	10/04 COVER 1 zaida
Suggested Link Details/Purchase
Content	WELDING RESEARCH -S287WELDING JOURNAL ature, the iron material from the plate re- acts with the excess oxygen provided by the lance. When the plate is very thin, the preheating time and focusing of the oxy- gen/flame stream play a minor role, and the plate is cut immediately by the lance flame. That is the reason RCSI is small for thin plates. When the cutting plate is thick, the cutting kerf actually played a role of focusing element; therefore, RCRI de- creases — Fig. 4. The performance differ- ence between modified and CAL lances in cutting iron or steel plates is most obvious in the range of 6–8 cm (2–3 in.) of plate thickness. At a given cutting plate thickness, the performance difference between CAL and modified lances decreases with the in- creasing oxygen flow rate — Fig. 5, 1⁄4-in. OD lances. At very low oxygen flow, the focusing effect substantially increases the efficiency of the oxygen. The modified lance cuts almost two times faster than the CAL lance. However, after the oxygen flow is increased, that difference disap- pears. It is also a proof that the inert wrap not only focuses the flame, but oxygen as well. It is instructive to calculate the cost of cutting both for the modified lance and for the commercially available lance. Data on cutting speed, lance burning speed, and oxygen consumption must be considered. The following cost data have been used in our calculation: 3⁄8-in. OD lances, CAL price $4.06/3 ft, modified lance price $4.57/3 ft, oxygen price/L $0.00419. The cost comparison is shown in Figs. 6 and 7. Figures 6 and 7 show the calculated cutting cost based on the data of cutting speed, lance burning speed, oxygen flow rate, and the unit price of a lance and oxy- gen gas. The figures reveal that the over- all cutting costs are lower for the modified lance compared to commercial lances. Oxygen consumption cost is about 35% of the overall cost for both the CAL and the modified lances at 50 lb/in.2(345 kPa). Oxygen consumption cost is about 45% of the overall cost for the CAL lance and 40% for the modified lance at 80 lb/in.2 (552 kPa). The reduced cost of using the modified lance is due to the facts that cut speed is increased and the material and fabrication cost of adding an inert jacket is also low. Adding an inert jacket increases the lance cost less than 50 cents. Conclusions The nonmelting, nonreactive jacket improves the wire-core lance performance through the following ways: The jacket stabilizes the lance flame. The hybrid iron-aluminum lance does not produce a stable self-propagating com- bustion regime without the nonmelting, nonreactive jacket at the oxygen flow rate of about 80 L/min. In the cutting process, the jacket reduces the flame extinction and soldering effect by reducing the heat loss and by direct contact between the lance and the cutting plate. Through the focusing effects of both oxygen and the lance flame provided by the jacket, the cutting time of the inert jacket modified lance is substantially re- duced. The cutting speed is increased by a factor of two for 6–8-cm-thick iron plates. The cutting cost of the modified lance is also much lower than that of the CAL lance because the modified lance has a higher cutting speed. The cost of the non- melting, nonreactive jacket is only mar- ginal. Acknowledgment The authors express their thanks to anonymous referees for their quantitative and constructive comments. References 1. Slottman, G. V., and Roper, E. H. 1951. Oxygen Cutting.New York: McGraw-Hill. 2. Brandenburger, E. 1975. New oxygen wire core lances. Metal Construction.617. 3. Davies, I. L., Fleischer, C. C., and Paton, A. A. 1987. Developing techniques for remov- ing activated concrete. Nuclear Engineering In- ternational32 (392): 45. 4. Brower, J. S. 1978. Underwater cutting rod. U.S. patent no. 4,069,407. 5. Sweetman, W. G. 1958. Chemical cutting method and apparatus. U.S. patent no. 2,918,125. 6. Paaso, C., Cariello, B., and Palumbo, A. 1991. Cutting electrode for underwater and land use. U.S. patent no. 5,043,552. 7. Moore, P. E., Strohl, R. L., and Soisson, L. R. 1985. Coated exothermic cutting. U.S. patent no. 4,544,139. 8. Hirano, T., Sato, K., and Sato, Y. 1983. Prediction of metal fire spread in high pressure oxygen. Combustion Science and Technology 32:137–159. 9. Sato, J. I. 1983. Fire spread mechanisms along steel cylinders in high pressure oxygen. Combustion and Flame51(3): 279-287. 10. Hlavacek, V., and Pranda, P. 2001. High- speed chemical drill. U.S. patent filed on June 1, 2001. 11. Kemp, M. D. N. 1986. The effect of lower quality oxygen purity in oxy-thermal cut- ting. Welding in the World24(3/4): 28–34. 12. Grosse, A. V., and Conway, J. B. 1958. Combustion of metals in oxygen. Ind. Eng. Chem.50:4663–4669. 13. Sircar, S., Gable, H., Stoltzfus, J., and Benz, F. 1991. Symposium on Flammability and Sensitivity of Materials in Oxygen-Enriched At- mospheres: Fifth Volume.Eds. J. M. Stoltzfus and K. McCilroy. pp. 123–131. Philadelphia, Pa.: ASTM. 14. Sato, J., and Hirano, T. 1986.Symposium on Flammability and Sensitivity of Materials in Oxygen-Enriched Atmospheres: Second Volume. Ed. M. A. Benning. pp. 118–134. Philadelphia. Pa.: ASTM. 15. Mellor, A. M., and Glassman, I. 1965. Pyrodynamics3:43–64. 16. Dean, J. L. 1985. Thermal burning rod. U.S. patent no. 4,541,616. wang qwkcorr 8/27/04 8:40 AM Page 287
Navigation	Previous Page / Next Page
Suggested Link Details/Purchase

Following Datasheets	10-2005-JENKINS-s (8 pages) 10-2005-POORHAYDARI-s (7 pages) 10-50TV_IPC-1752 (3 pages) 10-50TV_097_Rev_A (2 pages) 10-50TVC_IPC-1752 (3 pages) 10-50TVC_097_RevA (2 pages) 10-50TVC-S_IPC-1752 (1 pages) 10-50TVC-S_097_RevC (2 pages) 10-50TVR_IPC-1752 (3 pages) 10-50TVR_097_Rev_A (2 pages)
Check in e-portals	World-H-News Products Extensions Partners Automation Jet Parts
Sitemap Folder	group1 group2 group3 group4 group5 group6 group7 group8 group9 group10 group11 group12 group13 group14 group15 group16 group17 group18 group19 group20 group21 group22 group23 group24 group25 group26 group27 group28 group29 group30 group31 group32 group33 group34 group35 group36 group37 group38 group39 group40 group41 group42 group43 group44 group45 group46 group47 group48 group49 group50 group51 group52 group53 group54 group55 group56 group57 group58 group59 group60 group61 group62 group63 group64 group65 group66 group67 group68 group69 group70 group71 group72 group73 group74 group75 group76 group77 group78 group79 group80 group81 group82 group83 group84 group85 group86 group87 group88 group89 group90 group91 group92 group93 group94 group95 group96 group97 group98 group99 group100 Prewious Folder Next Folder