Skip to main content
SpringerLink
Log in

Determination of the Minimum Safe Purge Gas Flow Rate in Flare Systems with a Velocity Seal

  • Equipment
  • Published:
Chemistry and Technology of Fuels and Oils Aims and scope

Purge gas in flare systems is used to avoid burnback in the flare stack. We have used computational fluid dynamics (CFD) methods to calculate the purge gas flow rate in a flare stack with a velocity seal. We constructed a simulation model of the purging process for different purge rates. As the results show, the baffle size has a significant effect on the oxygen distribution in the flare. When the first baffle/seal diameter ratio is d 1/D = 0.92 and hydrocarbons are discharged in the flare, the minimum safe purge gas flow rate is 0.05 m/s. However, when the hydrogen content in the discharge gas is high, the minimum safe purge rate is higher: 0.1 m/s. But if the purge rate is maintained at the level recommended by API 521-2007 (0.012 m/s when discharging hydrocarbon gases), the ratio d 1/D should not be greater than 0.75. In this case, when discharging gas with high hydrogen content, the minimum safe purge rate is 0.02 m/s.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6

Similar content being viewed by others

References

  1. W. Y. Dang and A. F. Yu, “Study on the design pressure for water-sealed drum in refinery flare system,” China Safety Science Journal, 20, No. 9, 75-80 (2010). [in Chinese]

    Google Scholar 

  2. H. W. Husa, “How to compute safe purge rates,” Hydrocarbon Processing and Petroleum Refiner, 43, This work was supported by the National Basic Research Program of China (program 973), grant No. 2010CB226902.

  3. S. H. Tan, “Flare system design simplified,” Hydrocarbon Processing, 46, 172–176 (1967).

    Google Scholar 

  4. V. I. Panchenko, “Determining the safe purge rates for flare tubes,” Chemical and Petroleum Engineering, 29, No. 5, 205-209 (1993).

    Article  Google Scholar 

  5. D. Shore, “Making the flare safe,” Journal of Loss Prevention in the Process Industries, 9, No. 6, 363-381 (1996).

    Article  Google Scholar 

  6. S. G. Bryce and R. E. J. Fryer-Taylor, “Reducing the purge in hydrocarbon vent stacks,” Journal of Loss Prevention in the Process Industries, 7, No. 3, 249-255 (1994).

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. School of Urban Construction and Safety Engineering, Nanjing University of Technology, Nanjing, 210009, China

    Yong-Zhong Bai & Jun-cheng Jiang

  2. Qingdao Safety Engineering Institute, SINOPEC, Qingdao, 266071, China

    Yong-Zhong Bai & Peng Wang

Authors
  1. Yong-Zhong Bai
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Peng Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Jun-cheng Jiang
    View author publications

    You can also search for this author in PubMed Google Scholar

Additional information

Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 6, pp. 12 – 15, November – December, 2013.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Bai, YZ., Wang, P. & Jiang, Jc. Determination of the Minimum Safe Purge Gas Flow Rate in Flare Systems with a Velocity Seal. Chem Technol Fuels Oils 49, 474–481 (2014). https://doi.org/10.1007/s10553-014-0472-x

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10553-014-0472-x

Key words

Search

Navigation