The 66th “Rest Of” Power Plant Post
Originally Posted April 18, 2014:
When I was an electrician at the coal-fired Power Plant in North Central Oklahoma I inherited working on the Precipitators from Sonny Kendrick, the Electrical Specialist in the electric shop. One time after I had been struggling with the performance of the precipitator trying to lower the emissions of Fly Ash going out of the smoke stacks, I encountered a very odd situation.
One morning as I was walking out to the precipitator as I passed the Unit 1 boiler I noticed that a couple of tanker trailers were sitting outside the bottom ash area. Hoses had been attached to one of them and were running up the side of the boiler. What looked like a pump was running. I didn’t have a clue what was in the tanker. I figured it was just some routine thing that power plants did every so often to make things more interesting. You wouldn’t believe how many times Power Plant Men would come up with new and interesting things just to keep me in awe. (Of course, I am easily amazed).
Anyway, I didn’t really pay much attention to the tanker on the way to the precipitator. I just walked around the tankers that were there and entered the precipitator switchgear and up the stairs to the Precipitator control room where 84 control cabinets were waiting for my attention. On the way into the switchgear I had glanced up at the smoke stacks and noticed that the exhaust from the boiler was looking pretty good.
As I walked passed the control cabinets that controlled the back of the precipitator, I was surprised to find that they were powered up all the way and there wasn’t any sparking happening. Well. I thought. Maybe they are at low load and not much is happening inside the precipitator this morning.
As I walked between the two rows of cabinets toward the cabinets that controlled the transformers near the intake of the precipitator, my surprise turned into astonishment. I had never seen the front cabinets powered up to such a high level with no sparking. Everything was 180 degrees from the way I had left the cabinets the evening before when I was struggling to adjust the power to lower the emissions.
After going through each of the cabinets adjusting the power levels higher only to find that I was able to easily increase the performance even further, I returned to the electric shop for break. When I arrived in the electric shop office I told Charles that something very strange had happened this morning and I’m trying to figure it out, because all of the sudden the precipitator was operating at maximum efficiency.
After break I walked back out to the precipitator control room past the tanker trailers and found that everything was still running smoothly. “My work is done” I thought. I decided to go to the top of the precipitator and start working on fixing malfunctioning vibrators for the rest of the day.
I worked on the precipitator roof until noon, and then went back to the shop for lunch. I sat with Charles as we talked about movies we had seen. Charles was telling me about how the song for Ghostbusters had been on the radio. When the song said,
“If there’s something strange
in your neighborhood
Who ya gonna call?
Charles’ son Tim (not having seen the movie) thought that instead of saying “Ghostbusters” they were saying “Who ya gonna call? Charles Foster!” Besides being exceptionally cute, it was also an honor for Charles for him to hear Tim sing, “Who ya gonna call? Charles Foster!”
After lunch was over I went back out to the precipitator control room to check on the cabinets one more time. To my surprise when I walked through the row of cabinets, they were sparking again as they had been the day before! Not quite as bad, but bad enough that I had to go through the cabinets and adjust them back down almost to the levels where I had them before.
It took longer to adjust the cabinets down than it did to raise them in the morning. When break time came along, I was too engrossed in adjusting the cabinets to notice, so I continued working through break. It must have taken me close to three hours. At that time I was still using a small screwdriver on some potentiometers inside each of the cabinets to make the adjustments.
About the time I finished, all the sudden something happened. The cabinets began acting the way I had seen them in the morning! All the sparking stopped and the cabinets began powering up to the highest point they could go based on where I had set them. Ok. Now I needed to find out what was going on!
I walked out of the precipitator and headed for the Control Room. I walked past the tanker trailers and noticed that the pump was running again. I hadn’t thought about it, but when I had walked by them a few hours earlier they had been turned off. This was curious. I figured that it was more than a coincidence.
Pat Quiring was the Unit 1 Control Room operator when I arrived. I asked him what has been going on with Unit 1. I explained to him that when I arrived in the morning I found the precipitator running smoothly, then later it wasn’t, and just a few minutes ago, something happened again and there it was. Pat said two things were going on that day.
One thing was that we had been burning a pile of sand that had been soaked with oil. They had been mixing it with the coal at the coalyard and blowing it into the boiler with the pulverized coal in order to dispose of the hazardous waste. Hmm.. This was a possibility. I couldn’t see how the sand would make a difference, but maybe the mixture of the chemicals in the oil had something to do with it.
Then I asked him. “What about those tankers on the side of the boiler? Why are they there?” Pat said that we were also burning Vertan. Well, not “burning” exactly. We were destroying it in the boiler, because it was chemical waste that needed to be disposed and it is easily destroyed into it’s chemical components in the heat of the boiler.
“Vertan? What’s Vertan?” I asked Pat. He said it was some chemical used to clean boiler tubes. These tankers had been sent to our plant from another plant that had just had the boiler tubes cleaned, and we were just burning it off to get rid of it. They had a schedule they were using to burn the Vertan. They couldn’t just get rid of it all at once because it caused a buildup in the economizer that caused the airflow to be affected through the tail end of the boiler.
So, I wondered, maybe this has to do with airflow. Diverting the airflow to different parts of the precipitator could definitely affect things. The cabinets out in the middle of the precipitator definitely had different electrical properties than those out on the edge.
I suddenly realized that this was 1988 and the Internet was not readily available to the typical user, and the World Wide Web still had a few years before it was widely going to be used. Frustrated that I couldn’t just go “Google” something for another ten years, I did the next best thing that I could do. I decided to pay a visit to our Power Plant Doctor! I wrote about Doctor George Pepple in the post “Power Plant Doctor Does a Jig in a Puddle of Acid“. He was the head Power Plant Chemist.
I went to the Chemistry Lab and found George working away on some diabolical experiment. No. Not really, he was probably just testing some water samples. When Dr. Pepple was working on any kind of chemical test, he did it with such mastery and grace that it always reminded me of a mad scientist.
I asked George about Vertan. He explained to me that it was a chemical that was mixed in water and pumped through the boiler tubes to clean out calcium buildup and the like. I mentioned to him that I thought it may be affecting the operation of the precipitator and I was curious to know more about it.
Professor Pepple then explained to me that Vertan was called TetraAmmonia EDTA. EDTA? Yeah, he said, “Ethylenediaminetetraacetic Acid”. He said this just like my Animal Learning Professor, Dr. Anger used to say “Scopalamine” (See the Post “Poison Pill for Power Plant Pigeons“).
I wrote down this information and I continued monitoring the progress of the precipitator throughout the rest of the week. Each time the pumps were running on the Vertan trailers, the precipitator operated as if it was new and completely clean. Each time the pumps turned off, the precipitator reverted back to the regular mode of operation, only it would be a little better each time. By the time all the Vertan had been destroyed in the boiler, the precipitator was running very well on it’s own.
Over the weekend I went to the University Library at Oklahoma State University in Stillwater and Looked up TetraAmmonia EDTA. Not much had been written about it. I was able to find an article about it in a Journal. It had the chemical composition.
A few years later when the Internet became available I was able to find a better model of the Vertan molecule:
I mentioned that at the same time that the Vertan was being burned in the boiler, we were also blowing contaminated sand into the boiler in order to burn off oil that had soaked into the sand. At one point, I had to go work on the head end of the number 10 long belt to find a 480 volt ground in a circuit. When I arrived, I could see where the oil from the sand had caused the coal to cake up on the belt and cause a big mess where the conveyor dumped the coal onto the belt 12.
There didn’t seem to be any correlation between the times that sand was being burned. The process for burning the sand lasted a lot longer than burning off the Vertan. By the time that the sand was burned off, the precipitator was humming away operating at near maximum efficiency. So, it seemed as if the sand didn’t have anything to do with the increase in performance.
I was convinced that burning Vertan in the boiler was more convincing. If not Vertan, then just injecting water could have been a factor. Since the Vertan was in water and they were pumping large amounts of water into the fireball in order to destroy the Vertan. Maybe the increase in Humidity had something to do with the improvement.
A couple of years later when the “We’ve Got The Power” Program was underway (See the Post, “Power Plant ‘We’ve Got The Power’ Program“). Terry Blevins and I were investigating the idea that Vertan could be used to improve the performance of the precipitator. We found that Ammonia Injection was used to treat Precipitators.
This is done by injecting ammonia into the intake of the precipitator to treat it when it was performing poorly. This reinforced our idea that Vertan was the main reason that the precipitator had responded favorably during that time since Vertan broke down into Ammonia at high temperatures. Even then, we didn’t exclude the possibility that the increase of humidity may have also played a role.
Another team had the idea that injecting sand into the intake of the precipitator would improve the performance of the precipitator by sandblasting the ash off of the plates. They had seen this happen when sand had been burned earlier. I had rejected this idea as being viable. I knew that the velocity of the airflow in the precipitator was no faster than 4 miles an hour. Hardly fast enough to keep grains of sand airborne.
It was worth a try though, and the other team pursued the idea and ran a test by injecting the sand. It definitely wouldn’t hurt anything to try. The idea was rejected by the Steering Committee (Ron Kilman), based on my input, even though something extraordinary happened during the test. When this happened, I became the instant enemy of the team leader.
I will cover this dilemma in a later post (See the post “Making Friends from Foes – A tale of Power Plant Woes“). For now I will just leave you with the knowledge that because I had chosen Vertan over Sand, I had definitely made an enemy of a True Power Plant Man.