40 BULLETIX 894, U. S. DEPAETME^T OE AGEICTJLTTTEE. 
The temperature of the water can be controlled automatically by a 
thermostatic tank regulator, having the control bulb in the tank and 
the valve on the steam supply to the coils therein. 
The use of the tank in place of a hot well has many features which 
recommend it in many installations. Of first importance among 
these is the elimination of the hot water pump. When the tempera- 
ture of the water is within 20 or 30 degrees of the boiling point it 
becomes very difficult to pump and causes more or less trouble with 
the pump packing, etc. The use of the tank obviates this difficulty. 
One method of connecting the tank to the recirculating main is shown 
on figure 12. 
SIMPLIFIED HUMIDITY CONTROL. 
It is evident that the humidity may be changed by changing the 
kiln temperature, by changing the water temperature, or by both. 
Where more than one temperature schedule is used simultaneously 
in different kilns of a battery, the desired schedules are obtained by 
changing both the kiln and water temperatures during the progress 
of the run. Where only one low temperature high humidity drying 
schedule is used in the entire battery, such as would be required for 
slow drying heavy oak stock, the desired schedule may be obtained 
by maintaining the temperature of the spray water constant at one 
temperature throughout the run and in all kilns in the battery. In 
this case the humidity is lowered during the progress of the run by 
raising the kiln temperature. Where this method may be used only 
one well, one pump, and one water main are required and the mixing 
valves are not necessary. The water temperature is kept constant in 
the well by ahowing more or less fresh cold water to flow into it, 
the amount depending upon the difference between the temperature 
of the returning spray water and the desired temperature of the 
water in the weU. The proper method of piping connection for this 
type of installation is illustrated in figure 9. Figure 13 shows a 
simple method of installing the pump, including live steam jet line 
in well to raise the temperature of the water and cold water line to 
lower the well temperature. 
FILTERS. 
The recirculating water is very apt to contain dirt, sediment, or a 
stringy vegetable growth, which causes much trouble if it gets into 
the spray heads. This foreign matter should be intercepted by in- 
stalling a filter in the well between the return drain and the pump 
intake. Such a filter can be built of burlap stretched over wooden 
frames. The frames are made to slide in wood jambs on the sides of 
the well and may be easily taken out for cleaning and repairing. 
The return water from the spray chamber gutters should pass 
through three screens before reaching the pump intake. Several 
