Lime-Sulphur Concentrate. 37 
CHARACTERISTICS OF EQUIPMENT. 
_. COOKING TANK. 
Cooking tanks are built of wood, iron, or steel, or they may be of 
concrete. 
Wooden tanks are suitable only when steam is used for cooking, 
although there are instances of wooden tanks with iron bottoms that 
extend far enough up the sides to protect the wooden part from 
damage through direct contact with the open fire. Wooden tanks 
have one advantage over those of metal in that, wood being a poor 
conductor of heat, boiling will probably occur more quickly in a 
wooden tank than in a metal tank of equal capacity and surface. 
Wood tanks should be made of material not less than 14 inches 
thick. Tongued and grooved material is preferable because of the 
tight seams that can be made. It is advisable to strip the seams and 
to fill all joints with white lead paste so as to minimize the danger 
of leakage. 
Sheet or galvanized iron tanks should be of material not less than 
js inch thick and if the under side is to be in direct contact with fire 
a greater thickness is recommended. Tanks of cylindrical, cubical, or 
ebiend shape can often be obtained through local orchard supply 
houses or hardware dealers. The type shown in Figures 8, 9, 21, and 
23 will probably have to be specially built, but since the round 
bottom has a decided advantage over the flat bottom it is considered 
a good investment. 
oncrete cooking tanks are in use in small] lime-sulphur installa- 
tions. ‘Those that have been inspected by the authors seem to show 
no ill effects, but no investigation has been made to determine defi- 
nitely the desirability of using concrete for this purpose. Figure 19 
is a diagrammatic layout of a plant in which the cooking and dilu- 
tion tanks are of concrete. This particular plant has been in sery- 
ice several years. The plant illustrated in Figure 20, with the 
exception of the walls and roof of the house, is constructed entirely 
of concrete. If concrete is used for this purpose, it is advisable to 
employ a comparatively rich mixture, not leaner than 1:2:4 mix, 
and to use no aggregate larger than $4 inch. The walls and bottom 
of the tank should be reinforced in both directions in order to pro- 
vide against cracks due to temperature variations. During cook- 
ing the upper part of the walls will be cool as compared to the 
lower part and bottom. A thickness of not less than 6 inches is 
advised. 
Cooking tanks should have two outlets, one in the end nearest the 
filter tank and so placed that the bottom of the opening will be 3 
inches above the bottom of the tank and the other in the bottom as 
near as possible to the upper outlet. The upper outlet is used in 
withdrawing the concentrate, while the bottom outlet is used in com- 
pletely draining and cleaning the tank with hot water after 
each cooking. Neither opening should be less than 24 inches 
in diameter and each should be equipped with either a gate or quick- 
opening valve. A globe valve should not be used. 
The capacity of the cooking tank should be one and one-half times 
the volume of the mixture to be cooked, otherwise there is a likeli- 
hood of the solution boiling over and producting a dirty and sloppy 
condition about the plant. In Table 2, columns 8 and 12, are given 
