750 TRUEBLOOD. 



Each length of pipe in this superheater is filled from end to end with 

 a system of copper baffle-plates arranged as showTi in Fig. 7. It wilt 

 be seen that this device imparts to the steam a rotary motion, the 

 direction of which is reversed at each baffle. This insures thorough 

 mixing and the projection of particles of moisture against the hot 

 walls of the pipe. The baffle plates fit snugly into the pipe and make 



Figure 7, Arrangement of baffling plates in primary superheater. 



good thermal contact with the walls. To pro^^de for the elimination 

 of such moisture as may be separated from the steam bj' the action 

 of this series of baffle plates, the drip-cock K (Fig. 6) is placed at the 

 end of the superheater nearest the throttling apparatus. This cock 

 is normally slightly opened during operation. 



The furnace for the superheater consists of six lengths of | in. pipe, 

 screwing into manifolds at each end. It is fed with gas and air at 

 each of two opposite corners. A uniform fire is secured by independ- 

 ent control of fuel and air for each corner. The furnace is shown at 

 SF, Fig. 6; it is omitted from Fig. 5, to avoid confusion. 



After leaving the plug, the steam passes through two valves in 

 parallel {VL, Figs. 5 and 6) to the condenser (C, Figs. 5 and 6). The 

 use of two valves permits a nicer adjustment of pressure drop than is 

 possible with a single valve, and, by hahang the valve throttling, 

 makes it possible to operate at a lower mean pressure without the use 

 of an air pump on the condenser. The condenser consists of a helical 

 coil of 1 in. wrought iron pipe in a galvanized sheet iron containing tank, 

 through which passes a continuous supply of cooling water. The 

 condensed steam is received in glass jars and weighed. 



3. Pressure Measuring Appar.^.tus. 



The high side pressure is measured by means of a precision Bourdon 

 gauge {Gi, Figs. 5 and 6), made by the Crosby company, and of the 



