GISBORNE GAS COMPANY.

Poverty Bay Standard, Volume I, Issue 212, 18 August 1884, Page 2

GISBORNE GAS COMPANY.

Monday, the 18th of August, 1884, will be a day to be marked with a red letter in the archives of Gisborne, insomuch as it marks a progressive step in the career of the district. The project to supply the town with gas which was first resolved upon in April 1883, has to-day been carried to a successful issue, and the inhabitants will henceforth have no cause to complain of want of light so far as having the means of providing it at their disposal is concerned. Want of space prevents us enlarging on the topic to-day but we append a short description of the Company’s works and the mode of converting the mineral into the illuminating power, hoping thereby to enlighten some who have not paid much attention thereto. THROUGH THE WORKS.

We paid a visit to the Gas Works this morning, and through the kindness of Mr. Hawley and Mr. Peter Nightingale, are enabled to put our readers in possession of the following particulars. These we hope will give them a fair insight into the mode of making gas, and will assist those who have time to visit the works to understand the process. We can assure them that they will meet with ready replies to any queries they may ask from those employed. The ground occupied by the Company is about an acre in extent. The first portion of the works to which we turned our attention was that where the RETORTS AND FURNACES. are situated. The retorts are five in number although at present only two are being worked. They are changed about every six hours, and in them the process of extracting the gas from the coal is commenced. The coal is placed in the retort with a small quantity of shale—the latter a mineral which underlies the coal bed, and is nearly all gas. When a sufficient charge has been put in the door is closed, the furnace is fired up, and the gas in its crude state is, by the heat of the furnace driven off by way of an ascension pipe into the dydiaulic main. This is an iron chest which is three parts full of water. The pipe from the retort dips down into the water and the gas bubbles up through it, but the water prevents the gas from getting back into the retort, which would probably cause an explosion, while the retort is being charged. In this hydraulic main most of the tar is deposited. A tar main leads from the hydraulic main to carry the tar into the tar well, while

the gas is conveyed by another pipe into the condensers. And here we may interject the remark that fond mamma’s whose offspring are afflicted with whooping cough may speed-

ily cure the complaint by taking the child to the gas works and allowing it to inhale the ammoaial gas given off by the tar well. THE COOLER, or condenser, consists of a cast-iron bottom box, 7ft. 9in, by Ift. 6£in. wide, prepared with ten sockets on top for receiving the vertical pipes, and with a socket at each end for inlet and outlet pipes for gas, and with two sockets at one side for tar outlets. In its passage through these ten pipes the gas is cooled to the temperature of the atmosphere, which condenses the remainder of the tar (or nearly so), thus allowing it to run off by two small pipes fitted in the bottom box. From the the gas passes to the \ EXHAUSTER,

which is an elaborately designed engine, the purpose of which is to pump the gas out of the retorts and force it through the other apparatus into the holder. It is driven by a Cornish boiler placed over the retorts. When in use the boiler is heated by means of the hot air from the furnaces, which is so arranged that instead of being allowed to pass out of the main flue direct, is conducted along the outer sides of the boiler and back through the interior. The gas is then passed into the SCRUBBER, a cylindical body having an internal diameter of 2ft. lOin. and 9ft. high. It has three filling and discharging doors. The wrought iron tank is 2ft. Bin. in diameter and Ift. 6in. deep. The dip cisterm is 2ft. by l|ft. The scrubber is filled with coke and water, and through its agency absorbs the ammonia from the crude gas and also a small portion of carbonic acid gas and sulphurreted hydrogen. It is then conveyed to the PURIFIERS, Two in number, 6ft. square and 3ft. deep, with covers and lifting apparatus. They are charged with hydrated oxide of iron, which removes the sulphur, and then passes it on through the

STATION METER, An apparatus which registers the quantity of gas made, and also by means of a “ telltale ” makes a mark on the indicator if the stokers are lax in their duties and shows exactly when the retorts are changed. From here the gas makes its way into

THE HOLDER where it is stored. The holder has a capacity of 7,500 cubic feet. It is very strongly constructed, and in fact the whole plant is much better than that ordinarily in use. Front the outlet pipe of the holder the gas flows out through

THE GOVERNOR, which regulates the pressure according to the requirements of consumers, and thence into the street mains. Having got the gas so far the troubles of the manufacturer are ended, and the man with the bill takes up the running. The meter and governor and each purifier are provided with bye-pass valves, which allows the gas to flow past any part of the apparatus which may require attention without interfering with the manufacture.