The nesting of tanks six feet in diameter in a sixteen-foot square bay provides sufficient strength to make it possible to suspend the tanks from the floor beams above, suitably arranged, it further avoids the necessity of supports near to the tanks, which greatly facilitate cleanliness.
Situation of Surface Boxes.
—The grease content in the fertilizer is a matter of dollars and cents. When the oil is withdrawn from the tanks it cannot be seen and no matter how closely watched considerable oil will pass through to the surface box where it can be collected. Consequently the second story of the tank house is a high story with the surface boxes placed convenient to the second floor so as to be readily worked. Further reference to this is made later.
Press Room.
—The press room is arranged so that the press can be built directly beneath the surface boxes, from whence the car is passed to the press for pressing out the moisture.
Digesters.
—The “digester” indicated, together with its method of suspension and nesting has been successfully used and was the practice followed by a well known designer for a number of years. The diameter and height of the digester ordinarily used is 6 × 16 feet on the tank body. The writer invariably has specified half-inch thick tank steel for the reason that the increased thickness is of so little additional weight, and the labor being such a considerable factor, that it was thought well to provide this additional thickness to take care of corrosion and acid attack.
Little Neck Rendering Tank.
—Lugs can be placed in any position desirable for support. The little neck for filling needs no comment. It is provided with a six-point security and by the use of ring-bolts with male and female flanged closing and gasket, can readily be made steam tight.