SMOKE ELIMINATED.

Auckland Star, Volume LXII, Issue 291, 9 December 1931, Page 8

SMOKE ELIMINATED.

AUCKLAND HOSPITAL CHIMNEY. OXJ> PROBLEM SOLVED. ENGINEER'S. ACHIEVEMENT. In the past many people when desiring to know the wind direction' have been accustomed to take their observations from the smoke at the Auckland Hospital, but in future they will have to look elsewhere. By the application of scientific principles to the combustion of coal/ the black smoke that has been an unpleasant feature for years at the hospital has been eliminated. This result has been achieved by Mr. F. C. Jacobs, resident engineer . to the Auckland Hospital Board, after considerable investigation and experimentation. To-day, the hospital fires, which consume 4000 tons of coal yearly, burn with «fche same ferocity as before, but instead of thick black smoke being emitted from chimney, there is an almost imperceptible slight haze of heat waves. The coal burned at the hospital is Waikato slack, a lignite coal of low calorific value. Being of a very dusty nature, it presents more than the ordinary difficulties of satisfactory combustion. When discussing the black smoke problem at the hospital this morning, Mr. Jacobs, who has for three years been resident engineer in charge at the institution, said that tlie most erroneous ideas were prevalent on the subject. Coal was formed from vegetable matter which had been subjected for millions- of years to heat and pressure in the.earth. Because of the heat and pressure a slow decomposition of the most intricate character had taken place, and the cellulose-like compounds were gradually decomposed.; The net result was to split off hydrogen and oxygen in the form of water, together also with methane, and to leave most of the carbon, behind, so that the percentage of carbon gradually increased and the residual product became harder, drier and darker in colour.

Cause of Smoke./ -r >, "It is solely the-volatile;mattering coal that i≤ the cause-of black smose, said Mr. Jacobs. "If pure carbon is bnrui no smoke can be produced under■ aaj circumstances. The two chief cause a factory smoke are insnffideni-taupe* ture in the furnace and inefficient liruy If all the volatile matter, -and it. ism which causes smoke, is. to J** , ™ smokelessly, the furnace must r be W at a high temperature. JV *-«*?£ important to have sufficient ooom a given intensity of suction to. pnHjJ the necessary air through the fires, «JJ at the same time must he thick enoy to ensure efficiency." ._ • Mr. Jacobs said the black smoke ?* bleni was a world problem, Auckland it was exercising the the Power Board, railways and ou large users of Waikato coal. it .being, light and friable, a « draught invariably would draw- tw «* dust particles up the chimney -to r «J forth heavv clouds of black -smokeiM? dust, which settled on ration, causing residents much ance, especially the women- on wa-uufe days. No Extra Expense. ' "The burning of coals eej*"j£ and smokelesslv is a complex pg* owing to the immense venation chemical composition of web,— o i Jacobs. "The type of grates, air supply, whether ™*f ■ w for steam is high, requiring W-r ; be forced or not, the a material as coal in face oU" ■ t variables, and last, but; jot greatest- variable ot _an— * . factor in the shape of firemen -all are part of the problem. * u i£r at the all been successfully hospital without any TOst # The theory governing ti» £ der . combustion of coal has been loj,. stood, but. as in and practice are difficult owing to the great number on off . in" the composition ot coak 11 «, o f ent parts of the world, :the engineer is to bring oT & tice to such a point that Be diffiobject. Sufficient ■ evidence, oi, cnlties are presented bypracticaliy, chimney in the city. •mecn an * ca ' "There are one °* "'i wliidi'" I **. stokers on the market v j\ oi sucachieved a considerable cess in the direction smoke, but they are costfy l 0 ' entail'certain costs ,n . °?SS S beff here at the hospital tlie P roDiei " d 'Of solved without any expense, w now burn the slackest and- :*■£&? coal and-still have -tie : s _ , chimney." — . -