Maxi-Therm’s principal design revolves around the utilization of uncontrolled high-pressure steam within a vertical flooded u-tube heat exchanger (HX), where water flows through the tubes and steam in the shell. This innovative idea offers several advantages:

1. Elimination of Pressure Reducing Valve Stations and Safety Relief Valves: By leveraging high-pressure steam directly into the flooded HX, there's no need for steam pressure reducing valve stations or safety relief valves with vents to the roof. This simplifies the system architecture and reduces maintenance requirements.

2. Prevention of Flash Steam losses: The flooded HX is meticulously sized to ensure it remains flooded even during full load operation, maintaining the condensate outlet temperature below 200°F. This eliminates the occurrence of flash steam and negates the necessity for a flash tank with a vent.

3. Precise Control with Electric Actuated Condensate Control Valve: Our system incorporates an electric actuated condensate control valve to modulate the condensate flood level within the HX, based on the temperature of the hot water outlet. This ensures optimal heat transfer efficiency and provides at or below +/- 2 Degrees of set point.

4. Efficient Heat Extraction: The interface between steam and water inside the HX allows for precise control over the exposure of the tube bundle to live steam. This enables efficient extraction of both latent heat from steam as it changes phase and sensible heat from the condensate, resulting in maximized BTU extraction per pound of steam.

5. Motive Force for Condensate Return: The high-pressure steam within the HX generates a motive force on the sub-cooled condensate return line, overcoming any backpressure and facilitating the lift of condensate back to the boiler plant or condensate receiver without the need for condensate pumps.

6. Condensate Mixer for Simplified Return Line: Additionally, our system includes a condensate mixer, enabling connection of high-pressure steam (HPS) drip legs within the mechanical room to the sub-cooled condensate return line for a single line return setup.

7. Prevention of Corrosion: Operating on a flooded basis ensures that the system never operates under a vacuum. This reduces the amount of oxygen exposure, which is known to produce carbonic acid and contributes to corrosion on condensate return lines. Furthermore, the flooded HX design reduces thermal stress on the tube sheet, extending the lifespan of the HX.

In essence, our principal design not only streamlines system architecture and maintenance but also enhances efficiency, control, and longevity while mitigating corrosion risks, providing a comprehensive solution for steam to hot water applications.