408 



CEMENTS, LIMES, AND PLASTERS. 



mills the shale powder is delivered to a set of two bins and the lime- 

 stone powder to a set of five bins. These bins are so constructed as to 

 discharge automatically into a double elevator, whence the materials 

 are discharged into a double hopper over a tandem automatic weigh- 

 ing-machine, which weighs out the proper proportion of each material. 

 The two products are then mixed thoroughly by being conveyed together 

 by elevator E and conveyors 9^ and 9 to the steel bins feeding the tube 

 mills. There are six of these tube mills and they are driven in groups 

 by a 75-H.P. electric motor. 



" The tube-mill discharges feed onto a screw conveyor 10, thence to 

 the elevator EE, and thence to screw conveyor 11, which discharges 

 into two groups of stock bins. Screw conveyors 13 running under- 

 neath these bins take the material right and left to the elevator F, 

 which feeds the right and left screw conveyors 12 that discharge into 

 the kiln feed bins. There are ten of these bins and each one feeds one 

 rotary kiln." 



Actual Equipments of Dry-process Plants. 



The .present-day practice in dry-process plants is shown better by 

 the following data on the actual equipments of a number of these plants 

 than by any amount of general statements on the subject. Reference 

 should also be made to Chapter XXXI, where general crushing practice 

 is discussed. 



Plant No. 1. Uses limestone and shale. 



Limestone 

 1 Gates crusher 



Shale 

 1 Gates crusher 



Plant No. 



1 Mosser drier 

 1 kominuter 

 4 tube mills 

 4 kilns 



Limestone and shale. 



Limestone Shale 



1 crusher 



1 rotary drier 



1 Williams mill 



2 tube mills 

 2 kilns 



Plant No. 3. Limestone and shale. 



Limestone Shale 



1 crusher 1 tunnel drier 



1 rotarv drier 1 crusher 



1 dry-pan to 30-mesh 



2 Raymond pulverizers 



3 kilns, 50 feet 



