a stainless-steel hypodermic needle nozzle of 120 um diameter that was terminated slightly beyond the end of the feed tube. Compressed air entered the annular ring around the end and the flow of this over the liquid at the nozzle tip created a fine spray. To ensure complete evaporation, the mixing chamber was legged and heated by regulated power heating tapes. The temperature in the chamber was measured by a chromel-alumel thermocouple. Airflow fiom a compressor was controlled by a fin-needle valve and measured by a mercury manometer and rotameter. The metered air splits into two lines, both controlled by coarse and fine valves. One line fed directly into the annulus of the nozzle holder in the mixing chamber. The other fed directly into the top of the chamber to mix with the remaining mixture. About 15% of this flow was diverted through an elutriator (9). Fine control of the flow leaving the elutriator was provided by a needle valve. The purpose of the elutriator was to seed the gases for the Laser Doppler measurements. The mixture of vaporized liquid fuel and air left the mixing chamber and was blended with the seeded air fiom the elutriator before being fed into the burner via a fine control valve (IO), which, by throttling the flow rate, improved burner control. This enabled a steady flow rate to be obtained. All airlines were heated by regulated electrical resistance tapes to avoid condensation. Temperatures of the mixture were measured at the mixing chamber, burner tube inlet, the center of the top of the matrix, and above the drilled asbestos plate. Heated
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