Toward a Better Air-Assisted Flare Design for Safe and Efficient Operation during Purge Flow Conditions: Designing and Performance Testing

Abstract

In this study, a new air-assisted flare tip was designed, built, and tested under different operating conditions. Lacking sufficient energy to mix with air, low waste gas flow rates will lead to incomplete combustion of these gases. This increases pollutant emissions and soot formation which leads to a decline in flare performance. This flare tip design enhances the waste gas mixing energy through implementation of an air jet in a crossflow orientation. This is done by adjusting the exit area of the waste gas exit by injecting a radial jet of air from an inclined slot jet located around the flare tip. This flare tip design also provides protection for the flare tip from high flame temperatures that can damage through convective cooling. Several tests were conducted to assess the new flare tip design with varying waste gas flow rates of 5, 10, 25, and 120 standard liters per minute (SLPM). These tests also considered varying assistant air flow rates. In addition, test results showed high combustion efficiency of the flaring process and significant soot formation suppression. The new flare tip design yielded better flame behavior with respect to the flare tip, caused by the flame stability that prevented the flame from attaching to the flare tip.