Abstract
Hudson Avenue Station is a stoker-fired generating station of 770,000-kw rated capacity. The station was started in 1922 with 14-retort underfeed stokers of 355 sq ft projected grate and ashpit area and completed in 1932 with an installation of 15-retort stokers of 694 sq ft projected grate and ashpit area. Development of the rated station capacity requires that the latter installation of stokers burn coal at the rate of about 65 lb per sq ft per hr, using eastern semi-bituminous coal of about 14,000 Btu per lb as fired. On test, coal was burned at the rate of 75 lb per sq ft per hr for 48 consecutive hours, at a steam-generating-unit efficiency of 77 per cent.
The development of the various stoker units, of which there are five different types, is described and illustrated in this paper. This station was the location of the development by the Westinghouse Company of the first “link-grate” stoker, which was successfully applied here in a 15-retort design having a projected grate and ashpit area of 524 sq ft.
The 1932 installation of American Engineering Company’s Taylor stokers is equipped with manual zoned-air control, which divides the air supplied to the grate section into 69 separately controlled zones. These stokers are the longest single-ended underfeed stokers on record, measuring 26 ft 7 in. from front furnace wall to the rear of ashpit.
The various steps in the development of the underfeed stokers to obtain the desired capacities are described, and an apparent limitation in capacity of a purely underfeed stoker of any considerable length is discussed.
This paper discusses also the unburned-gas losses and the cinder losses in the heat balance of a boiler-stoker test. The cinder loss attains considerable magnitude in stoker operation at high-burning rates, and loss data are given for a number of stoker tests at coal-burning rates up to 75 lb per sq ft per hr.
The extent of improvement in efficiency in stoker operation over the period of ten years due to stoker design and associated equipment is discussed from the standpoint of the installations in this particular station, efficiency data being given in curve form for the various stoker installations.
It is the hope of the authors in presenting this paper that it will serve steam-plant designers as a basis of facts on efficiency and capacity possibilities of large stoker-fired installations in the present state of the art.
A companion paper by Messrs. Hardie and Cooper, of the Brooklyn Edison Company, entitled “The Test Performance of Hudson Avenue’s Most Recent Steam Generating Units” presents test data and describes the test procedure and methods.
