Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
권호 표지
DOI QR코드

DOI QR Code

Investigation of the LPG Gas Explosion of a Welding And Cutting Torch at a Construction Site

  • Lee, Su-kyung (Department of Safety Engineering, Seoul National University of Science and Technology) ;
  • Lee, Jung-hoon (Department of Safety Engineering, Seoul National University of Science and Technology) ;
  • Song, Dong-woo (Department of Safety Engineering, Seoul National University of Science and Technology)
  • Received : 2018.10.09
  • Accepted : 2018.11.02
  • Published : 2018.12.01
Download PDF
⟨ Previous Next ⟩

Abstract

A fire and explosion accident caused by a liquefied petroleum gas (LPG) welding and cutting torch gas leak occurred 10 m underground at the site of reinforcement work for bridge columns, killing four people and seriously injuring ten. We conducted a comprehensive investigation into the accident to identify the fundamental causes of the explosion by analyzing the structure of the construction site and the properties of propane, which was the main component of LPG welding and cutting work used at the site. The range between the lower and upper explosion limits of leaking LPG for welding and cutting work was examined using Le Chatelier's formula; the behavior of LPG concentration change, which included dispersion and concentration change, was analyzed using the fire dynamic simulator (FDS). We concluded that the primary cause of the accident was combustible LPG that leaked from a welding and cutting torch and formed a explosion range between the lower and upper limits. When the LPG contacted the flame of the welding and cutting torch, LPG explosion occurred. The LPG explosion power calculation was verified by the blast effect computation program developed by the Department of Defense Explosive Safety Board (DDESB). According to the fire simulation results, we concluded that the welding and cutting torch LPG leak caused the gas explosion. This study is useful for safety management to prevent accidents caused by LPG welding and cutting work at construction sites.

Keywords

HHGHHL_2018_v56n6_811_f0001.png 이미지

Fig. 1. (a) Complete view of the accident site; (b) Outside the trench; (c) Inside the trench where the ignition occurred; (d) Place where the torch was found inside the trench; (e) Welding and cutting rods, LPG, and oxygen tanks; (f) Welding and cutting torch.

HHGHHL_2018_v56n6_811_f0002.png 이미지

Fig. 4. (a) Damage to Building No. 1, disassembled ceiling; (b) Damage to Building No. 2, broken door and window; (c) Damage to Building No. 3, distortion of frame (beam); (d) Damage to Building No. 4, broken door and window.

HHGHHL_2018_v56n6_811_f0003.png 이미지

Fig. 5. Space for blocking foreign substances from the outside of the trench.

HHGHHL_2018_v56n6_811_f0004.png 이미지

Fig. 6. Simulation design for trench structure. (a) Trench structure illustration (Front); (b) Trench structure illustration (Side); (c) Trench structure illustration (Side); (d Trench structure illustration (Top).

HHGHHL_2018_v56n6_811_f0005.png 이미지

Fig. 7. LPG leakage analysis simulation according to heights in trench.

HHGHHL_2018_v56n6_811_f0006.png 이미지

Fig. 8. LPG concentration and accumulation height change in trench over time.

HHGHHL_2018_v56n6_811_f0007.png 이미지

Fig. 9. Warehouse damage.

HHGHHL_2018_v56n6_811_f0008.png 이미지

Fig. 2. Schematic diagram of the accident site.

HHGHHL_2018_v56n6_811_f0009.png 이미지

Fig. 3. Locations of four damaged facilities relative to the explosion.

Table 1. Accident timeline

HHGHHL_2018_v56n6_811_t0001.png 이미지

Table 2. Details of facility damage by estimated explosion period (7:10–7:27)

HHGHHL_2018_v56n6_811_t0002.png 이미지

Table 3. Simulation input data conditions

HHGHHL_2018_v56n6_811_t0003.png 이미지

Table 4. Results Summary of explosion power by DDESB (TNT equivalent mass of 13.23 kg)

HHGHHL_2018_v56n6_811_t0004.png 이미지

Table 5. Results Summary of explosion power by DDESB (TNT equivalent mass of 64.96 kg)

HHGHHL_2018_v56n6_811_t0005.png 이미지

References

  1. Ministry of Public Safety and Security, Fire statistical yearbook, 25-30 (2016). http://nfds.go.kr/ebook/2016/all/2016.html. Accessed on: 2 May 2017.
  2. Korea Joongang Daily Social affairs Section. https://news.joins.com/article/20113708, Accessed on: (2016).
  3. Bubbico, Marchini, "Assessment of an explosive LPG release accident A case study," J. of Hazardous Materials, 155, 558-565 (2008). https://doi.org/10.1016/j.jhazmat.2007.11.097
  4. Giovanni, C., Overpressure calculation for unvented partial volume deflagrations. J. of Loss Prevention in the Process Industries, 44, 323-333(2016). https://doi.org/10.1016/j.jlp.2016.09.009
  5. Lee, I. J. and Kim, R. H., "Safety Enhancement of LPG Terminal by LOPA & SIF Method," Korean Chem. Eng. Res., 53(4), 431-439(2015). https://doi.org/10.9713/kcer.2015.53.4.431
  6. Tamil Selvan. R., "Fire, Explosion and Dispersion Modelling of Automatic LPG Distribution System of High Rise Building Apartment," International J. of Science Technology & Engineering, 2(4), 276-277(2015).
  7. Boult, M., "Risk Management of LPG Transport Activities in Hong Kong," J. of Hazardous Materials, 71, 85-100(2000). https://doi.org/10.1016/S0304-3894(99)00073-4
  8. Roberts, A. F., "Thermal Radiation Hazards from Releases of LPG from Pressurised Storage," Fire Safety J., 4, 197-212(1981/82).
  9. Paki Turgut, "LPG explosion damage of a reinforced concrete building: A case study in Sanliurfa, Turkey," Engineering Fail-ure Analysis, 32, 220-235 (2013). https://doi.org/10.1016/j.engfailanal.2013.04.004
  10. Cocchi, "Overpressure calculation for unvented partial volume deflagrations," J. of Loss Prevention in the Process Industries, 44, 323-333(2016). https://doi.org/10.1016/j.jlp.2016.09.009
  11. Khan, Abbasi, "Major Accidents in Process Industries and an Analysis of Causes and Consequences," J. of Loss Prevention in the Process Industries, 12, 361-378(1999). https://doi.org/10.1016/S0950-4230(98)00062-X
  12. Khan, F. I. and Abbasi, S. A., "An Assessment of the Likelihood of Occurrence, and the Damage Potential of Domino Effect (chain of accidents) in a Ty," J. of Loss Prevention in the Process Industries, 14, 283-306(2001). https://doi.org/10.1016/S0950-4230(00)00048-6
  13. Zhang Licong, "A Numerical Simulation of Shock Wave Structure in Gas Explosion," Procedia Engineering, 26, 1322-1329 (2011). https://doi.org/10.1016/j.proeng.2011.11.2307
  14. Yang Lizhong, "Analysis of fire and explosion hazards of some hydrocarbon-air mixtures," J. of Hazardous Materials, A84, 123-131(2001).
  15. Ha, D. M., "Prediction of the Detonation Limit of the Flammable Gas and Vapor," Proceedings of the Korea Institute of Fire Science and Engineering Conference, 131-134(2008).
  16. Crowl, D. A. and Louvar, J. F., Chemical Process Safety: Fundamentals with application, Prentice Hall: New Jersey, 6-15(2002).
  17. Dadashzadeh, M., Khan, F., Hawboldt, K. and Amyotte, P., "An Integrated Approach for Fire and Explosion Consequence Modelling," Fire Safety J., 61, 324-337(2013). https://doi.org/10.1016/j.firesaf.2013.09.015