HOW ENERCON SYSTEMS WORK WITH VARYING LOADS

The Enercon System has proven itself since 1989. All of our plant installations have faced, and successfully handled, varying loads in both low and high-pressure steam systems. Plant conversions with widely varying loads include outdoor asphalt plants, metal plating companies that start up and shut down every day, and sawmills with varying wood species and schedules.

Common questions raised are: “How can Enercon orifice traps work with widely varying loads?",  “Are those variances controlled?”, and “Are those variances significant enough to produce a less efficient solution?”  What we have experienced is that all loads can vary, and that the Enercon orifice steam trap systems can handle varying loads if they are properly sized.

Steam flow through a system shows the turbulent nature of the steam and condensate mixture upstream of the trap. This turbulence is due to the different densities and traveling speeds of these two elements. This turbulence effectively blocks steam from passing through the orifice throughout most of the working range of the system. When there is 68% or more water present at the opening of the orifice, there is no measurable loss of steam. As the amount of condensate decreases, even with only enough water to block 25% of the orifice, the loss of steam is less than 1 kg (2 lbs) per hour at 700 kpa 170kg//hr (100 psi 375 lbs/hr) condensate. This 4:1 turndown ratio is the operating range of the orifice. As long as the amount of condensate is within this range the steam loss is very small.

Orifice Steam Loss with Varying Loads at a Constant Pressure Only

Systems with modulating control valves or solenoid valves rarely vary outside the guidelines for an orifice. Large process applications will usually have a modulating control valve. A modulating valve allows nozzle capacity to vary with pressure differential. When more heat is needed, the control valve opens to increase steam flow, providing greater pressure differential across the nozzle, as well as higher nozzle capacity. When demand drops, the control valve closes and pressure and condensate load are reduced, keeping us within the 4:1 turndown at which we size orifices. All modulating or on/off control equipment is convertible. In complete plant conversions, Enercon has converted 99% of the steam traps to orifice steam traps.