There are a number of factors that influence the heat transfer rate in liquid heat exchange. These all must be taken into account when implementing a direct injection steam tank heater.
- One of the primary factors is the size of the steam bubbles. Heat transfer occurs across the surface of a bubble. You need a surface area/volume ratio that’s large. A large bubble offers very little surface area/volume. Smaller bubbles offer much greater surface area in total, or per unit volume. This means that you must produce extremely small bubbles to achieve an efficient steam injection process.
- Next, you need a head of liquid over the injection point. It should be large and the steam pressure kept low so that the size of bubbles created is minimized. This means the more considerable the head of liquid over the injection point, the more steam bubbles will be able to condense before they hit the surface.
- The velocity of the a steam bubble at the injection point should be fairly low, yet still create enough momentum to draw water back into a steam tank heater’s perimeter. Lower bubble velocities allow more time for steam bubbles to condense. Yet momentum must be consistent to draw in liquid to mix with the steam in a steam tank heater’s mixing elements.
- Steam’s condensation rate is proportional to the temperature difference between the steam and the liquid into which it’s being injected. Obviously, this is the liquid heat exchange you’re aiming for. A liquid’s temperature should be controlled so that it meets the requirements needed for its use, but also maintains a temperature where your heat transfer rate is efficient and energy isn’t wasted.
To fulfill these concerns, we utilize the Scepter Tank Heater. The steam heater is a versatile yet straightforward tool for liquid heat exchange. As steam exits, the momentum created draws liquid into the module’s perimeter. This results in water mixing with steam through the mixing elements. They exit as co-rotating vortexes. Where the steam leaves, impingement mixing zones are created. This allows efficient steam injection mixing without noise or vibration.