Steam & Condensate Introduction
How does steam flow in a system? Steam coming from the boiler is distributed throughout the system by pipes referred to as steam mains or steam supply lines. Since steam is generated under pressure at the boiler, it will travel on its own through the system. Steam may travel in pipes at velocities exceeding 90 mph ; for this reason, care should always be taken to open and close valves slowly. What is condensate and why must it be removed from a system? When steam releases its heat energy, it condenses from a gas back to a liquid. This “condensed” steam is referred to as condensate ... which is nothing more than extremely hot water. As previously discussed, steam at 50 PSIG condenses back into water at 298˚F. Steam Traps were specifically designed for the removal of unwanted Condensate and Air . Condensate will form in steam pipelines due to radiation losses through the pipe walls. Drip Traps remove condensate from steam pipelines. However, the bulk of the condensate formed in the system occurs in the heat exchangers and other processes, and must be removed or the system would fill with water and impede the heat transfer process. In contrast to drip traps, Process Traps remove condensate from the actual process application (such as a heat exchanger).
System showing use of Steam for Heating in two different Process Applications: Steam Jacketed Kettle & Tank with Steam Coil (Vat Process)
50 psig Inlet Pressure
Roof
Steam travels through piping
Process 2
Process 1
Vat Process
Steam Jacketed Kettle
Drip Trap TD600S
Drip Trap TD600S
Steam turns back into condensate in the Jacketed Kettle just as it did in the radiator illustration
Condensate
Condensate
Process Steam Trap
Process Steam Trap
Condensate
Condensate
Vented Receiver
Boiler Feed Tank
Boiler Feed Pump
Pump
Condensate
Condensate Return Pump
Note the process steam traps draining condensate from the Steam Jacketed Kettle and the Vat Process, discharging into a condensate return line. Condensate is then drained into a vented receiver which is used to release flash steam from the hot condensate in order to neutralize the pressure in the condensate return line. Also note the drip traps used for draining condensate from the steam supply lines. Other components, such as control valves and pressure regulating valves that would be required to control steam pressures and product temperatures, have not been included for simplification purposes.
7
Tel: 610-495-5131 • Pottstown PA • USA •• www.watsonmcdaniel.com
Made with FlippingBook - Online magazine maker