The preparation of oxygen on a large scale by the Brin method is thus described:* The routine of the process begins with the pumping in of air from the atmosphere, which is passed into a large receiver containing caustic lime, and thence into a second and smaller receiver of caustic soda ; the latter acting as a check on the former in the removal of moisture and carbonic acid from the air. The purified air is then passed into large pumps, where it undergoes slight compression, and finally passes through a chamber for filtering out solid particles, and a distribu tor placed on top of the furnace, into the retorts. The large furnaces are built at an angle with the horizontal, and contain on each side twelve inclined retorts, of cast iron, of six and a half inches internal diameter, one inch thick and about ten feet long. These hold between 2000 and 300o pounds of barium in small lumps. A temperature of about 1300° Fahr. is obtained by the admission of primary and secondary air into a coke furnace, the carbonic oxide found being burnt into carbonic acid in the combustion chambers. By means of wall-holes in the sides of the fur naces one sees the retorts at a dull red heat. The heated barium abstracts the oxygen from the purified air, and the free nitrogen escapes up through an automatic valve, whence it passes out into the atmosphere. At the end of five minutes an automatic reversing gear reverses the work ing, a vacuum is created in the retorts, the air and impure oxygen in the connecting pipes are blown away, and the oxygen passes back through the pipes to a comparatively distant part of the works into the gasholder, which has a capacity of 2000 feet.
In another five minutes the reversing gear is again automatically converted, air passes into the purifiers, as before, thence to the pumps and retorts, and so on, for every five minutes of the day and night, Sundays as well as week days, all the year round. The maximum volume of gas capable of being drawn off can thus be seen to be very large. At the time of our visit only one of the furnaces and one set of retorts were at work. As showing the longevity of the barium oxide, the company are still using barium which was first employed in i886, when the Brin syndicate started working the process. After a time the barium is prone to cohesion, when it has to be taken out and broken up.
From the moment when the air is pumped into the purifiers until the pure oxygen leaves the compressor the process is practically automatic, save and except such attention as even auto matic machinery must have. Of special value in this, in that, when the air and impure oxygen are blown out of the pipes, the egress of atmospheric air is prevented. In atmospheric air there are, by weight 23.1 parts of oxygen to 76.9 of nitrogen, and by the Brin process about fifteen parts by weight of the oxygen are taken up by the barium monoxide.
OXYGENATE.—To unite or combine with oxygen. OXYGENATED WATER.—See Hydrogen Peroxide. OXYGENOUS.—Pertaining to or derived from oxygen.