How to charge Main steam ejector

In this post i’ll share How to charge Main steam ejector in steps. Main steam ejector Create vacuum using Venturi effect to pull exhaust steam to condenser from turbine casing.

Before charging steam ejector

1. STG synchronized with moderate load
2. Stable vacuum pressure with Startup Ejector.

Starting preparation: How to charge Main steam ejector

1. Drain 2^nd stage condense via 2^nd stage drain bypass valve.
2. Darin 1^st stage condense via 1^st stage drain valve.
3. Note: Keep distance from Drained water it could cause severe heat burn due to its high temperature.
4. Keep both stages drain valve open around 8 to 10 min.

Filling condensate line with DM water

• After draining both stage condensate start filling DM water via DM water filling valve.
• While filling DM water via DM water filling valve keep 1^st stage,
  • Keep 1^st stage condensate drain valve(V05) closed
  • Keep 1^st stage drain ball valve(V06) open.
  • Keep condensate return valve (V10) closed.
  • Observe water temp drained from 1^st stage drain ball valve(V06)
  • Keep filling DM water until cool water come from 1^st stage drain ball valve(V06) .

Why we need to monitor water temp from 1^st stage drain ball valve(V06)

Its is the proven way to ensure that Condense line filled with water  and no air trapped inside of the condensate return line.

After Filling condensate line with DM water

• Close DM water filling valve.

Ejector Steam Header charging

• Start opening Main Ejector steam valve (V11) Slowly.
• Open the drain valve of Main ejector steam header. To let the temperatures any pressure rise while let condensate drain from Main ejector steam header .
• Meanwhile, partially open the second stage steam venting valve (V09) to a range of 10% to 15%.
•  Keep 2^nd stage steam venting valve (V09) always around 5% open.(After taken Main ejector online)
• Keep the drain valve 5% opening of the main ejector steam header.

Main Ejector Steam charging

1. Open both 2^nd stage steam intel valve V01 & V02 at once around 30% .
2. Wait couple of minutes to raise pressure in 2^nd stage ejector stream line.
3. Then Open both 1^nd stage steam intel valve V03 & V04 at once around 30% .
4. Monitor vacuum pressure buildup  in 2^nd stage ejector stream line pressure gauges.
5. In 2^nd stage ejector stream line Vacuum pressure gauges vacuum pressure should be around -0.09Mpa to -0.1Mpa.

Take Main Ejector Online

1. Then open Main ejector vacuum valve (V12) to take Main ejector online.
2. While opening Main ejector vacuum valve (V12), open 1^st stage condense return valve to condenser(V10) 5% to 10%.
3. Must keep an eye on STG Vacuum pressure, while opening Main ejector vacuum valve (V12).
4. At this time STG Vacuum pressure should increase a bit. Because both of the ejectors are pulling vacuum (Main ejector & Startup ejector).

Take Startup Ejector Offline

• Keep the both ejector online to monitor vacuum pressure.
• Then Close the startup ejector vacuum valve.
• Closing speed of the startup ejector vacuum valve should be fast.
• After Talking Starup ejector offline vacuum pressure should be stable.

If vacuum pressure fall’s

• If vacuum pressure starts falling while closing startup ejector Steam valve , start open startup ejector vacuum valve to take startup ejector online.
• Then find the reason behind why vacuum pressure falls and take necessary step.