650 



CEMENTS, LIMES AND PLASTERS. 



both cylinders, while the cylinders are further connected at each end 

 by two sets of adjustable or swinging arms B, which prevent the 

 joints being affected by the expansion or contraction of the cylinders. 

 At the head or upper end the inner cylinder projects beyond the outer 

 cylinder, passing into a stationary head or air chamber E to the hot 

 air flue D of the furnace G with which it is connected. At the lower 

 or discharge end is another stationary head E forming an air chamber, 

 through an opening in the bottom of which the dried material is dis- 

 charged. This head is supplied with a damper to regulate the tem- 

 perature, which gives perfect control. 



The cylinders are set at an inclination of about f inch to the foot. 

 The outer cylinder is secured to two heavy rolled steel-bearing rings, 



FIG. 161. Ruggles-Coles drier. 



which rest and revolve upon eight bearing wheels supported by oscil- 

 lating arms or rockers. The lateral motion of the cylinder is taken 

 up by four thrust wheels. The drier is revolved by a cast gear H 

 secured to the outer cylinder, and this is driven by a shaft and pinion 

 K extended beyond the end of the machine and supported in two 

 babbitted journal boxes fitted to the frame. The entire machine is 

 fitted and secured to a heavy frame of 8-inch I beams braced and 

 framed together and usually set on a concrete foundation. The exhaust 

 fan is placed where most convenient to drive, and is connected with the 

 outer cylinder by a suitable flue L. The furnace G is built inde- 

 pendent of the rest of the drier, and is connected with the head end of 

 the inner cylinder by an iron flue D built with fire-brick. A specially 

 designed burner is substituted for the furnace when oil, gas, or powdered 

 coal are to be used. 



The heated air passes through the inner cylinder (which is shown 

 by the dotted lines in the illustration) and returns, between the inner 

 and outer cylinders, to the fan. The direction of the hot-air current 

 is shown by arrows. The wet raw material is fed into the space between 

 the inner and outer cylinders through a spout C in the stationary 



