IO 
ANNUAL REPORT 
CS 
a 
In regard to the capacities of the different machines Professor 
Carpenter gives the following summary: : 
Machine. ee ape ens Power used. 
ROCK CTUSHELS 5, Gator seemed on emcee cur earene a ae 1.1 horsepower per ton. 
WollSAerce ke Goo ee [oo Sepenenannc 1.5 horsepower per ton. 
Griffin mill, TOC Bee eee 1.5 to 3 27 to 33 horse power. 
Cruisin wall, GWM co Sao - 0.8 to 1.5 27 to 35 horsepower. 
(Crouagen wall, Cokes oboco seo 5: pL aywey Zn) = 16 to 24 horsepower. 
Ball mills, on rock to 20 mesh. 2 to 4 20 to 30 horsepower. 
Tube mill, producing dust.... 2 to 4 70 to 80 horsepower. 
Dust Collectors. —One class of machine found lacking in Amer- 
ican cement mills is the dust collector of European works. Every 
effort is made there, made compulsory by law, to separate out the 
dust floating in the air as much as possible, and hence regular 
plants of good size are installed for this purpose. The dust being 
decidedly injurious to health, it should be the aim of every man- 
ufacturer to install such dust collecting plants, especially since 
them cost 1s not cream. and) im patt. isprepaid: bytes time 
cement dust collected. The writer has visited plants in which the enor- 
mous amount of dust floating in the air was a positive menace to health. 
By the exercise of a little engineering skill this state of affairs could be 
remedied without difficulty, just as has been done in other industries. 
There are a great many appliances on the market for collecting dust by 
exhausting air from the working space, passing it repeatedly through 
settling chambers and catching the remaining particles by means of 
cloth filters. 
MECHANICAL EQUIPMENT. 
Dry Process——We can now summarize the mechanical equipment 
of dry grinding cement plants as follows: 
Limestone. Clay or Shale. 
t. Rock crusher. i. Coarse etinder > \@alls) cor 
2: Intermediate grinder, rock crusher, if hard.) 
(rolls, disintegrator or 2. ANOtaty adtayets 
Kent mill). 3. Disintegrator. 
3. Limestone Bins. 4. Clay bins. 
The materials, each in separate bins, are now discharged from the 
bins by gravity on to horizontal belt conveyors and fed into two smaller 
