High efficiency gas burner - for preheating oily metal swarf, reclaiming foundry sand, or mfg. perlite or vermiculite

摘要

A volatile or combustible material (1) is removed from a subdivided material (2) by feeding the latter into a flame so the particles of material (2) are sepd.; but the flame temp. and air present do not produce any chemical alteration in the pure material (2) thus obtd. The process is pref. used for (a) removing oil from metal turnings, using a ratio of total air/air needed to burn the fuel in the flame and the oil of 0.7-1, esp. 0.8, with heating at 500-1000 degrees C. for 1/2-5 seconds to prevent oxidn.; (b) regenerating foundry sand, using an oxidising flame with air factor 1.3, with flame temp. 650-700 degrees C and heating the sand for 0.1-0.5 seconds; (c) mfr. of perlite from sand, or vermiculite from mica, using an oxidising flame with air factor below 1.05; flame temp. 1500-1700 degrees C and heating for 0.1-1 seconds. The claims include plants for each process (a, b, c) all using a burner fed with gas flowing radially and axially and with two counter-current tangential air inlets. The burner described in FR 73.38298 is esp. applied to all three processes (a, b, c) using the min. amt. of fuel and recovering heat in waste gases where possible.