Condensate Demineralizer System Flashcards
The CD demins are capable of handling what severity of a condenser leak and for how long?
1 GPM on a continuous basis
What vessels are in service during full flow?
5 vessels and 1 in standby with blowdown demins in bypass
What vessels are in service during full bypass?
none, all 6 in standby with blowdown demins in service
what is decon factor?
concentration in/concentration out
What is meant by resin spent or saturated?
saturated with impurities
What is the pressure in the demins?
460
What is meant by standby?
inlet open and outlet closed
What would high D/P across a demin indicate?
clogged resin trap
what would low D/P indicate?
Channeling thru the resin bed
What is the purpose of the resin traps?
To catch resin before it goes to the SGs
What system provides air for resin transfer, cleaning and mixing of resin?
service air
What system provides motive air for AOV in CD demin valves?
IA
What cools the demin sample coolers?
WC normal chilled water
What system provides chemical needed for cation resin regen and what chemical is used?
System - Chlorine injection
Acid
What is used to regen anion resin and where does it come from?
System - chemical production
Caustic and it comes from water resources
What does NH do for the CD demin system?
powers the pumps in the system and heaters for the caustic tank
Also powers the PLC
What is the resin ratio?
2 to 1
Cation 2 and anion 1
Where can the demin outlet valves be controlled from?
Normally the control room
Can be at the local panel
What is the purpose of the 4 white indicating lights?
shows when vessel is in service, standby, resin transfer, or resin rinse
How may switches are at the local panel for each vessel?
six switches
There is a selector switch to determine which switches are going to be operated
Why is a slow pressurization of a service vessel necessary?
To not displace resin bed with the high pressure of the condensate header
What do the red lights mean?
Rinse, resin transfer and crud removal
What light indicates vessel is in service?
green
PLC performs what 5 processes?
Full regeneration
Partial regeneration
Service vessel to cation vessel
in vessel air max
mix and hold to service vessel
What is purpose of the PLC?
used to start or stop the automatic regeneration or resin transfer cycles
What do we use the cation regeneration vessel for?
Used for cation-anion resin separation and cation regeneration
Where does the resin addition hopper drain to?
cation vessel
What happens if pressure gets too low on the inlet of the cation vessel?
Vent valve is interlocked with a pressure switch that will cause the valve to go closed
When the air scrubs are in automatic, how long will the pressure switch reverse flow to unplug the screen?
30 seconds
What is the cation resin cleaning cycle?
Cation vessel timer that lowers water level to the resin bed level
Air scrub timer
Compact resin timer
Backwash timer
Number of cleaning cycles
What is the anion resin cleaning cycle?
Anion vessel timer that lowers water level to the resin bed level
Air scrub timer
Compact resin timer
Backwash timer
Number of cleaning cycles
What is the purpose of the mix and hold regen vessel?
Receives anion and cation resins until it is ready to be transferred to a service vessel or the blowdown demin system
What is the purpose of the acid day tank?
400 gallon tank that contains 93-96% sulfuric acid used for cation regen
How do we determine the level in the acid day tank?
Ultrasonic detector that displays on a local meter
How is the acid day tank fill valve interlocked with the level switch in the tank?
Fill valve closes on high level in the tank
What type of pumps are the 2 acid pumps?
Positive displacement
What are the 2 interlocks with the acid pumps?
low level in the tank
flow switch measures dilution water flow to the mixing tee will stop the acid pump on a low flow
When outlet valves open, drain valves closes
What is the purpose of the caustic day tank?
2500 gallon tank that contains 8% sodium hydroxide solution used regenerate anion resin
How is the caustic day tank fill valve interlocked with the level switch in the tank?
Fill valve closes on a high-high level in the tank
What is the purpose of the three banks of heaters in the caustic day tank?
Maintain the caustic at 115-120F
What type of pumps are the two caustic pumps?
Centrifugal
What is the purpose of the caustic pumps?
Supply caustic solution from the caustic day tank to the anion regen vessel
What would cause the caustic pumps to shut off automatically?
Tank low level
What is the purpose of the regen water transfer pumps and where are they located?
Take suction on the CST and supply water for various resin transfer operations
Located on concrete skid north of the CST
Concerning the waste collection tank, where is water directed to from X2 discharge valve?
High TDS sump, which can be discharged to the CWNT
Normally used at the beginning of the regen process prior to sampling by effluents and during acid and caustic injection when conductivity is very high
Where does X1 direct the water to?
Waste water (less than 1000 ohms) to the low TDS sump, which is then typically pumped to the CW system
What is the purpose of the turbine building acid transfer pump?
Provide acid to the day tank in the CD demin system
Provide acid injection for pH control in the CWNT
Where are the turbine building acid pumps?
by acid storage tanks outside
What powers the turbine building acid pumps?
NH
Why does the turbine building acid transfer pump have a bleed hole in its discharge check valve?
to assist in overpressure protection of acid
What feature of these pumps help prevent mechanical seals that could possibly leak?
Magnetic shaft coupling
What signal could stop the turbine building acid transfer pumps?
low low level in either storage tank
What is the capacity of the turbine building acid storage tanks?
11,000 gallons
