STEAMING TESTS. 
By L. P. Breckenridge. 
EQUIPMENT. 
The steaming tests under the Heine boilers have been continued under practically the 
same conditions as the 78 trials made during the period of the Louisiana Purchase Exposi- 
tion. For convenience the principal proportions of the boiler settings are shown in the fol- 
lowing table: 
Leading proportions of the two Heine water-tube boilers used in the fuel-testing plant. 
Boiler Boiler 
No. 1. No. 2. 
Rated capacity of boiler horse power. . 
Water-heating surface square feet. . 
Superheating surface 
Grate area square feet.. 
Air space through grate percent.. 
Available stack draft inches of water. . 
Height of steel stacks feet. . 
Area of steel stacks square feet . . 
Number of 3|-inch tubes on each boiler 
Usual steam pressure carried pounds. . 
210 
2,031 
None. 
36.4 
35 
.75 
115 
7.67 
116 
80 
The two boilers used for these tests are exactly similar in construction and setting. Each 
is provided with its own stack and fed by its own injector. The scales and instruments used 
in the trials are frequently checked and maintained in an accurate condition. 
IMPROVEMENTS AND ADDITIONS. 
After the completion of the World's Fair series of steaming tests a few changes in the 
settings were made, as follows: 
A McClave rocking grate was installed under boiler No. 2. It was thought that some 
coals could be handled more satisfactorily on a grate of this type and this proved to be the 
case. The B. F. Sturtevant Company loaned the plant a forced-draft outfit, consisting of 
blower and direct-connected steam engine. This has been set up so as to discharge air into 
the closed ash pits under each grate. By the aid of a light draft it has been possible to burn 
lignites high in moisture with fair results. A series of trials with slack coals and dried lig- 
nites is contemplated later. 
The brick walls have been given two coats of paint and all cracks and openings have been 
carefully stopped with asbestos paste. A special air-leakage test box has been used to 
locate leaks of air in the settings and all leaks have been promptly stopped. 
During the first weeks of this series of trials several gas-mixing devices were tried in the 
combustion chamber, such as fire-brick honeycombs, but they lacked durability, perhaps 
because of faulty construction and inferior material. A honeycomb wall was then built of 
very large fire-clay shapes, 6 by 12 by 18 inches, which withstood the heat for six months. 
Bull. 290—06 3 33 
