GAS MANUFACCTURE.

Colonist, Volume XLVIII, Issue 11559, 21 February 1906, Page 2

GAS MANUFACCTURE.

To the Editor. Sir,— -If the Council aocepts^fthe word of the gas manager, Westport coal is doomed.- You leporbed two Council mootings ago that he said ''Newcastle coal had solved the question of thick tar. " Your contemporary reported that in answer to Councilor Webley ho said "if all Newcastle coal was used there would bo no trouble with nnpthalene. " If that is true the Council have no alternative than to exclude Westport coal fit .the earliest; opportunity. That is, I presume of some importance to the" City. We have a nice little fleet of locally owned steamers dependent in some measure upon back freight for success. Tho loss of gfreight on 3000 tons of coal must bo a serious item to them. Wo have a small foundry which keeps that litlo fleet; in repair. "This, I should judge, en- j ablc3 them 3to keep their men fully | employed when orders are not coming i in from outside. Previous to the Anchor Line obtaining ihe coal contract thoy wore selling steamers. With the loss of the contract that may occur again. Hut yet, if the statement of tfho gas manager is correct, the Council have no alternative than of giving up Westport coal or running the gasworks as a commercial venture. .Rut is tho statement correct? In my opinion the facts don't warrant the statement. Westport coal has been in use in the gasworks since ISiM. During the whole of the time in tho old gasworks they havo boon remarkably | -free from choked ascension pipes or "thick tar." In support of this experience I produce the opinion of the gas managers, published in 1890. Port Chalmers: "The coal is clean to work, and does not cause any stopped pipes. " Napior: * "The coal is of good quality, giving its gas freely, the retort mouth and pines remaining clear and frao from stoppage." Westport: "The coal is clean, free to work, no such thing asjstopped ascension pipes." Wellington: "The ascension pipes during the test were entirely free from stopped pipes." Invorcargill : " I found whilst working tho coal that choked ascension pipes no longer troubled us." This is conclusive evidence that thick tar (choked ascension pipes) is not nroduoed by Westport Coalbrookdale'coal. It is well known that "thick tar" (choked ascension pipes) is produced by working the retorts at too great heat. «Eed or orange color is the normal heat, anything about that tends to distil the tar into pitch and stop the pipes. Now, with regard to napthalone, we might dismiss that at once, as the peculiar product of Westport coal, as at present we are using Newcastle coal with it and napthalene was never more prevalent than now. I was informed by a Councilor that 31 complaints came in in one day. Now, what has been the experience at the gasworks? I write from knowledge, napthalene has always been present, more or less, whatever coal has been us«d. Of late years it has been very troublesome, always more so in tho light temperature of summer, and is found most frequent in consumers' service pipes, wbero they pass through a damp, cold spot. As a proof of this latter some years ago the present foreman sat up some purifiers in the yard, charged them with wet limo,and kept the lids 000 l with wet matting, with the resultthat nnpthalene was caught wholesale. During my year of oflico I learned that this process had boon discontinued, but not tho reason. Now, let us sco what wo can learn from tho chemical production of napthalene. "It is tbo product oi' high temperature." It is produced best "by boiling old tar in air until ita gets thick by tbo evaporation of tho water. It is then retorted. A connecting tube links the retort to a glass receiver, which is cooled to a j temperature of Vi to 10 Fahrenheit, j which condenses it into thin eolorj less transparent flake?, which are vary solvable in alcohol or ether. " (Graham's Elements oil Chemistry). Now what can we gather from tho foregoing facts. Ist— That the lowest possible temperature (red heat), should be used in burning off Westport coal, which "gives its gas so freely. " 2nd— That as napthnlene is a constituent of tar. and is condensed at a temperature of Mto 10 L l '. . the condensing plant shouldjjbo sheltered from the sun, and kept cooi by water to condense out every atom of tar. land throw down any r^nihnlcne that may bo in existenco. Ik t in putting in new services caro snould be taken Ito avoid wet spots as git nears tho J melor. This is ihe conclusion I have arrived at, and I don't think anyone can deny that it is; a reasonable one. I am, etc , J. PIPER. P.S. — Asa proof that the condensing plant has not done its work, tar, 1 understand, has been found both in Tory street and Wellington Terrace, two of the shadiest streets in Nelson. P.S.S.— Tho problem to be solved by gas managers was how to get so rich hydro carbon as naptbalene C2O H8 to the gas jet of the consumers. Owing to incandeaoent lighfeingjnot requiring rioh gas, the problem now

id hfcw to prevent its pnxiucriou, ao.l if income* measuie it is promicei low ft) prevent it getting into thn name and services, „..„ I ' J.P,