Caption title. At head of title: Project summary. Distributed to depository libraries in microfiche. "Jan. 1986." "EPA/600-S2-85-106."

This report documents a continuation of Phase 4 of a research program to quantify emissions from, and efficiencies of, industrial flares. Phases 1 (Experimental Design) and 2 (Design of Test Facilities) were reported in EPA- 600/2-83-070 (NTIS No. PB83-263723). Phase 3 (Development of Test Facilities) and initial work in Phase 4 (Data Collection) were reported in EPA-600/2-84-095 (NTIS No. PB84-199371). Further data collection during Phase 4 is reported here. Initial results were limited to tests conducted burning propane/nitrogen mixtures in pipe flares without pilot light stabilization. The work reported here extends the previous results to other flare head designs and other gases and includes a limited investigation of the influence of pilot flames on flare performance. The following results were obtained: 1) Flare head design influences the flame stability curve. 2) Combustion efficiency can be correlated with flame stability for pressure heads and coanda steam injection heads. 3) For the limited conditions tested, flame stability and combustion efficiency of air-assisted heads correlated with the momentum ratio of air to fuel; the heating value of the gas had only minor influence. 4) Limited data on an air-assisted flare show that a pilot light improves flame stability. 5) The destruction efficiency of compounds depends on the structure of the compounds. 6) For the compounds tested in this program, the destruction efficiency of different compounds could be correlated with the flame stability curve for each.