Section 3: Bag House

Question 1

1. What is the function of the Bag House?

Answer 1

The baghouse separates the ash from the flue gases

Question 2

2. How many compartments are there on the bag house and how many bags are there in each compartment?

Answer 2

Unit 2 – 28 compartments
Unit 3 – 32 compartments
204 bags per compartment

Question 3

3. How soon should the bag house hopper heaters be put in service before start-up?

Answer 3

24 hours before

Question 4

4. List the items that should be checked before putting the bag house in service.

Answer 4

Check Compartments for individuals or tools
Close all 3 doors
Close Vent Damper and turn off Vent fan
Rack in Deflation damper, Reinflation damper, Outlet damper, Shaker motor, and Hopper heater
Open Inlet damper
Take out of maintenance

Question 5

5. What should the inlet temperature be before starting the bag house?

Answer 5

185 degrees

Question 6

6. Describe how to put the bag house in service and how to take it out of service.

Answer 6

Baghouse In Service
Reset High temp trip alarms
Close Bypass Dampers, alternating between East and West compartments, 1 damper at a time, once temp reaches 220 F
Wait for Opacity to settle to a normal range
Start Deflation fans
Start cleaning cycle in Auto
Start the ash system

Baghouse Out of Service
Contact CR and stop cleaning cycle
Turn off Deflation fans
Call up Bypass Dampers on East and West sides, open 1 at a time while monitoring Opacity.

Question 7

7. Explain how a compartment goes through a cleaning cycle.

Answer 7

Reinflation and Outlet dampers close
Settle time
Deflation damper opens and closes
Settle time
Shaker Motor energizes
Settle Time
Reinflation and Outlet dampers opens

Question 8

8. Explain how you would detect a blow bag in a compartment.

Answer 8

You would watch the trend when a compartment is going through a cleaning cycle. There will be a dip in opacity followed by a spike near the end of that compartments cleaning cycle.

Question 9

9. How is a blown bag isolated to a single compartment?

Answer 9

Watch the opacity trend and use the compartment trend to correlate which compartment is causing the spike in opacity.

Question 10

10. If a bypass damper is kicked open by accident, how do you close it again?

Answer 10

Send the bypass damper a signal to close or

Manually close the bypass damper

Question 11

11. Describe the procedure for taking a compartment out of service for inspection.

Answer 11

Place compartment in maintenance
Rack out and place hold cards on Deflation damper, Reinflation Damper, Outlet Damper, Shaker Motor, Hopper heater
Close Inlet Damper and place hold card
Open Vent Damper 25%
Open all 3 doors
Turn on Vent Fan

Question 12

12. What should a bag house operator do if a shaker failure alarm occurs?

Answer 12

Go check bearing and linkage on the shaker

Check shaker motor breaker

Question 13

13. What should an operator do if the Delta P on one side of the bag house is 2” higher than the other side?

Answer 13

Call a Control Room Operator to check if one of the ID fans are biased to one side.

Question 14

14. Can you trip the bag house on a high inlet temperature? If so, what is this temperature?

Answer 14

Yes. 425 degrees F

Question 15

15. Can you trip the bag house on a low inlet temperature?

Answer 15

No.

Question 16

16. What is the desired deflation range in 10ths of an inch?

Answer 16

0.1 to 0.3 of an inch

Question 17

17. Can the bag house be operated with only one deflation fan? If so how can you set it up to run on one fan?

Answer 17

Yes.
Close outlet and inlet of deflation fan you are wanting to pull out of service.
Alternate cleaning cycles.

Question 18

18. At what differential pressure will the cleaning cycle start on the bag house?

Answer 18

5 InWC