Steam jet heaters are used for the direct heating and circulation of liquids with steam in vessels and tanks. This kind of steam jet heater has an axial steam feed and the liquid laterally enters the suction connection. The steam condenses instantly when contacting the liquid.
Advantages
- Easy control of heat transfer capacity by adjusting the steam/water ratio
- Easy installation particularly in small vessels
- Even distribution of heat due to circulation of the vessel fluid
- Low-noise heating of all kinds of liquids in vessels
- No pressure or heat losses
- Problem of heat exchanger surface contamination eliminated
- Straightforward construction
Applications
Steam jet heaters are used in all processes, where liquids in vessels and tanks have to be heated (and circulated) and where the direct contact between steam and liquid is no problem.
Range of Operation
- A steam overpressure of at least 1.5 bar necessary.
- Short connections not restricted by valves, measuring devices, etc.
- Liquid level at least 1 m above the suction
- Optimal operation at supercritical steam pressure gradient, i.e. the ratio of the water pressure at the suction to the absolute steam pressure, less than 0.54.
- The operation at temperatures is between 60 °C and 90 °C in vessels open to atmosphere
- Liquid temperature reaches more than 80% of the boiling temperature
- Use of several small heaters rather than a single big one.
- Introduction of an air line at nozzle plane (this greatly intensifies the movement of the circulating liquid, avoids rattling when the fluid is cold and reduces noise).
In case
Either of the following improvements on the installation is essential, to prevent uncontrolled condensation and reduce noise:
Materials
- Cast iron
- Cast stainless steel
- Other materials on request
- Steel or stainless steel
- Temperature change resistant porcelain
