Remember in physics class when the professor demonstrated the venturi effect.  The experiment most likely had water or compressed air passing through a nozzle.  As the fluid is constricted in the nozzle it’s velocity increases and as we know from the Law of Conservation of Energy, the pressure at the constriction decreases.  This decrease in pressure will then draw in a second fluid and entrain it with the motive fluid.  This principle is exactly what we see in steam ejectors where of course the motive fluid is steam.  This second fluid can really be any such as air, chemicals, or flash steam.

Steam ejectors are quite simple devices with no moving parts and also are extremely durable.  An ejector is commonly used as a vacuum pump to draw ingressed air from the condenser on a turbine at power plants.  An ejector can also function as a thermocompressor to siphon flash steam and entrain it with the motive steam.

Great software tool from the DOE on pumping applications and it is free……

The Pumping System Assessment Tool (PSAT) is a free online software tool to help industrial users assess the efficiency of pumping system operations. PSAT uses achievable pump performance data from Hydraulic Institute standards and motor performance data from the MotorMaster+ database to calculate potential energy and associated cost savings. The tool also enables users to save and retrieve log files, default values, and system curves for sharing analyses with other users.

http://www1.eere.energy.gov/industry/bestpractices/software_psat.html

We are trapping kettles and a dishwasher (25 psi steam) and then running our condensate lines to a pump in a utility closet.  We need to run the lines under the slab due to space limitations. 

What material should we use for the condensate return line?  Any tips on the best way to accomplish this?

The best method for improving steam system energy efficiency, reducing chemical costs, and reducing make-up water costs is to return the maximum quantity of condensate to the boiler plant.

There are several factors that impact the reliability, performance, longevity, and maintenance requirements for the condensate piping system. Some of these factors are listed below:

• Condensate line sizing that factors condensate liquid, and flash steam quantities.

• Location of the condensate line with respect to the process equipment.

• Locations of the condensate branch line connection into the main condensate headers.

• Insulation techniques

An important factor to increase overall steam system efficiency is to maximize the temperature of the returning condensate. This permits high thermal cycle efficiency for the overall steam system.

Read the full Best Practice:    http://www.plantsupport.com/download/csbp.pdf