1 / 25

U NIVERSITY OF M INNESOTA Dept. of Environmental Health and Safety dehs.umn

U NIVERSITY OF M INNESOTA Dept. of Environmental Health and Safety www.dehs.umn.edu. Hazard Analysis Process for Adding Amines to Steam System C. Moody, A. Streifel, and M. Nagel. Southeast steam plant. Background. Peak campus steam demand - 450,000 lb/hr Hospital demand – 20,000 lb/hr

blithe
Download Presentation

U NIVERSITY OF M INNESOTA Dept. of Environmental Health and Safety dehs.umn

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. UNIVERSITY OF MINNESOTADept. of Environmental Health and Safetywww.dehs.umn.edu Hazard Analysis Process for Adding Amines to Steam System C. Moody, A. Streifel, and M. Nagel

  2. Southeast steam plant

  3. Background • Peak campus steam demand - 450,000 lb/hr • Hospital demand – 20,000 lb/hr • Corrosion of boilers, coils, pumps, traps and piping • Increased maintenance and energy costs – $1M per year

  4. Causes of corrosion • Corrosion caused by formation of carbonic acid • CO2 + H2O  H+ + HCO3- (carbonic acid) • Major sources of CO2 • Dissolved gas in make-up water • Thermal breakdown of NaHCO3 and Na2CO3 • Oxygen enhances corrosion

  5. Amine addition • Add neutralizing amines to keep pH range at 8.5 - 9.2 • Morpholine condenses soon after release to protect close-in piping • Cyclohexylamine protects far reaches of condensate piping

  6. Health Effects • Eye irritation • Irritation of upper respiratory tract • Dermatitis and sensitization from skin contact

  7. Amine Type OSHA PEL (ppm) FDA limit in steam (ppm) Odor Threshold (ppm) Morpholine 20 10 0.14 Cyclohexyl-amine 10 10 0.90 Health standards

  8. NIOSH Health Hazard Evaluations • 1982 – Museum study • Diethylaminoethanol (DEAE) produced eye irritation and dermatitis • Air samples - 0.01 ppm • 1988 - Electrical components factory • Nausea, dizziness, throat irritation • DEAE and cyclohexylamine added at 4x normal strength • 1989- Nurses in humidified nursery & newborn ICU – Eye and upper respiratory irritation • Cyclohexylamine and morpholine

  9. NIOSH Evaluation -1993 VA Medical and Research Center • Morpholine and cyclohexylamine • Fatigue, allergy symptoms, eye and upper respiratory irritation • Air, surface and steam samples • Air samples not exceeding minimum detectable concentrations • Detectable concentrations in surface samples • Measured concentrations in condensed steam samples • Recommended no amines for humidification

  10. Potential campus exposures • Humidification of sensitive patient areas • Medical device sterilization • Irritation for students and staff when added in excessive amounts to steam • Food preparation

  11. Control Options for Hospital • Clean steam generators • Direct steam humidification with monitoring and control

  12. Team approach to evaluate proposal • Facilities Management Department • Contract steam plant operator • Department of Environmental Health and Safety

  13. Options for amine addition • Inject amine based on: • pH of condensate return • Steam demand • Grab samples versus real-time monitoring • Metered injection

  14. Proposal • Inject amine based on steam demand • Use computer to calculate injection rate • Use chemical metering pump • Install analyzer to continuously monitor downstream concentration • Use analyzer signal to prevent overfeed of amine

  15. Metering Pump

  16. Analyzer

  17. Monitor

  18. Failure analysis • Conduct “What If” analysis based on description of monitoring/control system • Review possible failures • Evaluate control features   • Make additional recommendations for monitoring and control

  19. What If Analysis

  20. What If Analysis …

  21. Recommendations • Certify amine concentration • Request written permission of the University to change amine concentration • Route alarm conditions to central monitoring point • Take independent steam samples

  22. Results • Real time analyzer • Amine concentrations 1.0 - 2.5 ppm • No complaints of irritation or odor

  23. Benefits and Conclusions • Safety and health assurance • Patients, employees and students • Cost effectiveness • Alternative to clean steam generators • Reduce maintenance and energy costs • Process hazard analysis useful

  24. Craig MoodyCraig Moody, CIHDepartment of Environmental Health and SafetyUniversity of Minnesotamoody002@umn.edu612-626-4399

More Related