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Direct steam Injection water heaters

A direct steam injection heater provides a cost-effective method to heat water and other fluids by injecting steam directly into the fluid. The direct injection heater is designed to handle a wide range of flow rates and deliver hot fluids at precise temperatures.


  • Precise temperature control 
  • Instant hot water or other fluid 
  • Large turn-down ratio 
  • Low vibration and low noise level


  • Improved process reliability 
  • Enhanced process flexibility 
  • High-efficiency energy utilization 
  • Low maintenance costs 


How direct steam injection heaters work

High-pressure motive steam enters the heater through the motive body and passes into the nozzle. As the motive steam passes through the nozzle, the pressure drops and the velocity increases. This velocity will increase until it reaches sonic velocity in the nozzle orifice.

The stream of high-velocity steam leaves the nozzle and passes through the suction body to enter the throat, where it is brought into contact with the fluid to be heated. Entrainment of the fluid occurs as the motive steam jet transfers energy to the low-pressure fluid stream.

The flow progresses through the throat and the two streams mix resulting in uniform cross-sectional velocity. As the flows mix, the steam condenses and the liquid absorbs the heat as well as the kinetic energy in the steam jet. All of the steam is condensed in the liquid stream before the mixture exits the throat and passes into the process piping.