Crusher info   -   Rohrer's Quarry

Primary Crusher - Centrifugal to Metal Discs

Motor - 300 hp  x 745.7 Watts/hp = 223710 Watts = 223.710 KW
223.710 KW/3600 sec/hr = .062142 KWH
x 3600 sec/hr x 24 hr/day x 30 day/mo = 1.611e5 KW/mo

Feed   -  2ft. - 4 ft. limestone        Mohs Hardness  4.0

Ave. Kwh/mo.  =  15573 or 15573/1.611e5 = 9.69% operating 

Ave. tonnage/mo.  =  84811 short tons

			   D                       sqrt(60/D)   tons @ 60u
Dust created     # 200 (75 micron)    =   914 tons  x  .894   =   817.1
		 # 100 (150 microns)  =  1259 tons  x  .632   =   795.7
		 # 50 (300 microns)   =  1791 tons  x  .447   =   800.6
		 # 30 (600 microns)   =  2724 tons  x  .316   =   860.8
                                         ____                     _____
					 6688                     3274.2/6688 = 49%

15573 Kwh/6688 tons = 2.328 Kwh/Ton for this particle distribution.
Using .49 x 6688 tons above, 2.328 Kwh/Ton/.49 = 4.75 Kwh/Ton @ 60u.

% dust = 6688/84811 = 7.89%

Vertical Shaft Crusher

Motor - 250 hp x 745.7 Watts/hp = 186425 Watts = 186.425 KW
186.425 KW/3600 sec/hr = .051785 KWH
		    or
Motor - 250 hp x 550 (ft-lb/sec)/hp = 137500 ft-lb/sec
3.76616e-7 KWH/ft-lb/sec x 137500 ft-lb/sec = .051785 KWH

Feed  - AASHTO # 57  (3/8" to 1 1/2")  (3+12)/8 =15/8 = 1.875" = 47,625u
12 tph  of - #30 (600 micron) dust  .051785 KWH/12 tph = .004315 KWH/Ton
If run at 85% of HP rating, .85 x .004315 KWH/Ton = .003668 KWH/Ton.

Average Graduation of - # 30 dust :

	Sieve Size             % Passing  % Not Passing   % Trapped

	#  30 <= 600 u            99.9           .1           .1
	#  50 <= 300 u            85.6         14.4         14.3
	# 100 <= 150 u            61.8         38.2         23.8
	# 200 <=  75 u            44.3         55.7         17.5
				   0.0                      44.3
							    _____
							    100.0

			  Jerry Russell
The energy required to reduce solid rock to 60 micron powder is about 20 kwh/ton:
However, concrete is softer than rock, and a round number for the energy required
to crush concrete is around 1.5 kwh/ton: For other sizes, sqrt(60/D).