The Golden State: Where & How to Live, Secure, Visit, Enjoy and Thrive in California

Hot Water Suply

The rapidity with which the water will circulate within the tube will depend on the difference in temperature, that is, the difference in weight of the two columns d and b and the various resistances.

4. A single tube a, Fig. 3, having a partition b will operate the same as the two tubes of Fig. 2 when heat is applied at one side. But, if the partition is removed, the upward and downward currents will mingle and interfere, thus retarding the circulation. The circulation in a tube without a partition will be very slow and uncertain if the tube is small in diameter.

If the divided tube is laid in a horizontal position, the circulation will still take place, but at a much slower rate. If no partition is present, the circulation will be very slow and imperfect.

5. . The circulation of water in a pipe system used for cooling purposes depends on a change in the density of the water by cooling instead of by heating. The ice or refrigerating liquid should be applied near the top of the descending column/; the material that is to be cooled should be allowed to touch only the ascending column, and, if possible, be placed at its base. In this way the greatest possible difference in density of the ascending and descending columns will be obtained.For efficient heat transfer, water should be heated from below and cooled from above. It conducts heat so poorly that the heating or cooling depends very largely on circulation.

6. Circulation Between Separate Vessels.—Water can be heated by a fire located some distance from the storage tank, as illustrated in Fig. 4. The heater a is located directly over the source of heat, a gas flame in this instance, so that it will be subjected to the direct heat of the fire, and is connected by pipes b and c to the storage tank. The water in the heater a will then receive heat from the flame and thus is made less dense, causing it to ascend in the flow pipe c and enter the tank. Cold water enters the heater a through the return pipe b to replace that leaving it through the pipe c. A continuous circulation is thus maintained between the storage tank and the heater a, the currents flowing in the direction of the arrows.