Conventional storage tanks with sparge pipes (simple pipes with drilled steam distribution holes) tend to have uneven water temperature control, steam hammer, heavy vibration caused by collapsing steam bubbles, and low low energy efficiency as steam bubbles escape to atmosphere due to incomplete condensation . The modulating steam control valve will start to close as the storage tank temperature approaches the set point, resulting in a lower steam flow. Many times the steam control valve will “hunt” or modulate continually due to the uneven temperature throughout the storage tank.
Direct steam injection heaters can be used in place of sparge pipes to provide rapid, accurate, and consistent heating of water by injecting steam directly into the water inside a mixing chamber. The direct steam injection heater provides two solutions to the above problems:
1. Replace the sparge pipe with a direct steam injection heater. The water in the storage tank is circulated through the direct steam injection heater to maintain the desired temperature set point for the water in the tank.
2. Replace both the sparge pipe and the storage tank and use the direct steam injection heater to provide hot water on demand.
A direct steam injection heater can be used in place of both the storage tank and the sparge pipe to control the water temperature within +/- 1° F; eliminate steam hammer, thermal noise and vibration; and reduce the amount of steam required to heat the water by up to 30%. A direct steam injection heater requires minimal space in contrast to the storage tank/sparge pipe arrangement.