Installation With Soaking Troughs

When the clays are rich and require soaking in troughs, the following arrangement maybe adopted (Fig. 154). An endless band brings to the pug-mill the clay which has been soaked in the troughs, and after pugging the clay falls into a machine which transforms it into bricks.

We suppose in this installation that the clays do not need to be separated. Rich clays should generally be mixed: Fig. 155 shows an installation in which the mixing mill is placed above the soaking troughs. These troughs are provided with doors in one side, and near these doors is placed a pug-mill. The workman cuts the clay out of the troughs vertically and throws it into the pug-mill. Thence it goes to the moulding machine.

Estimate of an installation of this kind, producing front 25,000 to 30,000 bricks per day of 10 hours.

Francs.

2 mixing mills, at 1100 francs...

= 2,200

2 pug-mills, at 1800 frances...

= 3,600

2 cylinder machines, at 1600 francs...

= 3,200

Belting, gearing, etc...

800

Motive force : 4 horse-power for the mixing mills, 8 to 10 for the pug-mills, 6 to 8 for the moulding machines - in all, 25 horse-power, costing for engine, broiler, and erection, about....

15,000

Lift or tramway with waggons, soaking troughs, and sundries....

6,200

31,000

Building .............

The daily output requires a staff of 1 engine-driver, 2 men for the mixing mills, 2 men to spread the clay in the troughs, 2 men to fill the pug-mills, 2 cutters, and 3 men to take the bricks to the drying-rooms - altogether, 12 men.

Net cost of 1000 bricks : 0. 22 x 0. 11 x 0.065.

Installation For Manufacture With Powdered Clay

We shall give as a last example of installations, one for manufacture with dry clay. The dry state is obtained by natural means, or more frequently by warming in a stove or in the kilns. The clay, having been crushed by a mill with perforated pan, falls into a receptable below, whence a lift takes it to a sifting cylinder. The powder is received into a damping machine, and the tailings are returned to the crushing mill. The clay having been suitably moistened is once more mixed in a mill and finally falls into a receptacle, whence it reaches the press through a conduit. These presses (Fig. 157) are placed near the kiln, for the bricks manufactured by them are hard enough to be at once fired.

The estimate of such an installation is as follows: -

Francs.

2 crushing mills, at 5350 francs .........

= IO,700

2 sieves, at 675 francs ...........

= 1.350

2 damping machines, at 835 francs........

= 1,670

2 mixing mills, at 3000 francs .........

= 6,000

5 moulding machines, at 5300 francs........

= 26,500

Belting, gearing, lifts, etc...........

3,000

Motive force : 10 horse-power for the crushing mills, 6 for the sieves and damping machines, 6 for the mixing mills, 20 for the moulding machines - in all, 42 horse-power, costing for engine, boilers, and erection, about .

20,000

Sundries...

1,780

Total for machines .

71,000

building, about....

9,000

Total .

80,000

The staff comprises: 1 engine-driver, 2 men to put the clay into the crushing mills, 5 men for the machines - altogether, 8 men.

Interest at 4 per cent, on 31,000 fr. = 1240

4340 fr.

Francs.

Depreciation ,, 10 ,, ,, = 3100

Per 1000: = 4340/6000 = 0.723..........

0.723

12 men at 5 fr. a day = 60 fr., or, per 1000, = 60/30....

= 2.000

Coal, 1.25 kilos per horse-power-hour =

310 kilos at 25 fr. the ton . . = 7.25 fr.

12 fr., or, per 1000, 12/30

= O.4OO

Oil and maintenance, etc. . . 4.25

3.123

Extraction of the clay, per 1000 bricks...............................

1.877

Total cost .

5.000