LOW-GRADE GAS.

Sun (Christchurch), Volume VII, Issue 2047, 6 September 1920, Page 10

LOW-GRADE GAS.

■ QUESTION OF PRESSURE. HAS IT BEEN REDUCED? Further complaint with reference to the quality of gas supplied by the j Christehureh Gas Company, Ltd.. is contained in the following letter received by the editor of The Sun from "Thermos":— "In your issue of August 20 you publish" a entitled "Low-| Grade Gas." Therein it is stated that' numerous complaints have been* made about the quality of the gas supplied to consumers by the Christehureh Gas Co. Also that'suggestions have been made that the pressure has been reduced and that an iui.hu- proportion of water gas is present in the mixture. "The officials of the company say it is entirely due to the quality of the , Newcastle coal brought here by the j .Japanese steamer Tensho Maru. Now,! considering the price paid for this coal, j, excluding the heavy freight (which was : promptly passed on to the consumers), ; the writer thinks that the answer given . bv the company's officials is far from , satisfactory and that the first part of ; your paragraph hits the nail on the , head. These are the reasons for that opinion:— ! "(]) Average Newcastle coal is well j known to have a high gas-giving value, j Evidence of this is supplied by the I. recent news item to the effect that on j the'gas analysis submitted to the Italian : Government, it has given an order fori] an 8000 tons trial shipment for coalgas making. I "(2) Average Newcastle coal has aj high coking value, hence its value toj the Christehureh Gas Co. as a source I for producing water gas. Even iiij Sweden, where large quantities of coke; are used for metallurgical and other! purposes. Newcastle coal is taking aj, leading place. "(3) A mixture of coal and water-; gases gives a considerably lower calorific r intensity than that given by coal-gas:' alone; therefore, a larger quantity must; necessarily be burnt to supply the J amount of heat needed for each particular purpose. Also, by addition of L water-gas the percentage of ethyline j is lessened, and this directly affects the. luminosity. " (4) The lower the company keeps its • pressure, the greater the amount of gas i must be used, for a large portion of the! heat which should be absorbed rapidly J bv the substances treated is lost or neutralised by atmospheric temperature,! especially in cold weather ; "If the above theories are correct, I then the Gas Co. is a handsome winner j every time." The above letter was submitted to Mr j E. C. Bishop, general manager of the company, who denied that the pressure j had been reduced as described. New- j castle coals vary in quality to a very j great degree, he said. In norfnal times, j when, the company was able to make I contracts, it was always specified that | the coal should be supplied from eer-1 tiin mines only. In these times of a { shortage of coal the company, in order; to keep the gas supply going, had to ac-, cept any coal available, no matter what was the price. In common with all other essential industries, great anxiety was experienced in obtaining supplies. Some j of this coal would not even coke, and this caused even greater difficulty in working. Notwithstanding these difficulties, a very even quality of gas had been maintained except on one or two occasions only. These occasions happened several weeks ago. A mixture of coal and water gas did not "wive a lower calorific intensity, as reference to any text-book would show. An en-, deavour was made to keep the calorific j values as even as possible, and at about Ihe same level as was universally accepted in the United Kingdom. As to the statement that the company .was a handsome winner every time, he only wished that results would justify this. If "Thermos" knew what the company had to pay and contend acair.si, no doubt his opinion would be modified. Under any circumstances, it • was a matter of pride with the company that it should supply consumers with the best quality of gas possible to obtain from the classes of coal which had to i be used. Mr Bishop added that he : thought that it could fairly be claimed that the company hail kept the supply ] going as well as, if not better than, was j the ease in any other town in the Do- [ minion. A Sun' representative was shown a large number of charts relating to the pressure maintained each day. These | showed considerable uniformity, al-1 though in the absence of technical knowledge on the part of the pressman it is not possible to say whether the average j rate of pressure could be considered j good or not. | j