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 As you have certainly heard by now, I have been tasked with the installation of a new Fiber Flow Drum out at the mill. The old drum was being replaced due to maintenance issues. The basic purpose of the drum is to take old paper and turn it into pulp such that it can be cleaned and made into new paper again. This exists to be able to recycle old paper into new paper. |
 The drum was built in Finland and then shipped over here to the states in a few pieces. The two halves were welded together, a gear was installed on it, along with two support rollers. When it came time to replace the old drum, we had to take out the old drum and then install the new drum into the same location. I know that you probably have seen some of these pictures before, but I was so busy doing the installation that I neglected to get any real good shots of the change out. I did ask the contractors to get some pictures as the work progressed, and they did. The work took about 9.5 days working around the clock. There were some manufacturing issues when the drum was to be installed. |
 The drum arrived on our site exactly 1 month late. This delay caused us to delay our annual outage such that the prep time on the new drum had time to be performed. Then during the outage, we had a few problems with our manufacture. The upper vat walls (the vat is what goes around the screening section of the drum and collects the pulp) was made such that the length of it was 1 inch too long, and 4 inches too tall. So that we had to waste 2 shifts in a modification to the upper vat and make it fit onto the existing lower vat. |
 After that, when the new drum was sat in place, it ended up being laid out such that the inlet of the drum to the first support roller was also about 1" to long. This doesn't seem like much, but it made both of the support rollers not sit in the middle of the trunnions, but to one side which will most likely wear grooves into the trunnions or support rings or both. This measurement error also put the girth gear off center from the pinion gears. Now instead of the gear mesh being centered in the pinion gears, it is skewed to the down hill side of the pinions (the drum is set on a 1 degree slope such that the paper will run down hill to the screening section from the pulping section. |
 In this picture you can see the new drum (right) being unloaded from the trailer and you can also see the old drum in operation to the left of the picture. The truck the delivered the drum from Houston to here had 92 tires on the ground. The trip took 4 weeks to complete and covered 2450 miles. The semi truck averaged 1.4 miles per gallon and the assembled rig was 195 feet long from bumper to bumper. |
 The drum was changed out using hydraulic jacks. The jacks were controlled with different hydraulic cylinders such that they controlled the drums movement in three different directions (X., Y., & Z.). Some of the other contractors that bid this job wanted to use cranes, but it would require two cranes; a 500 ton and a 300 ton, this way it only required some jacks. The way that it turned out was that the drum was lifted up at night both times - coming out and going back in. |
 The old drum (shown here) weighs about 160 tons and the new drum weighs about 200 tons. The old drum was 4.00 meters in diameter and 95' long, and the new one is 4.25 meters in diameter and 95' long. The new drum is guaranteed to have a throughput of 1,700 tons of paper per day as opposed to the 1,500 tons of paper per day that the old one was capable of. We are currently taking bids from people to come in and cut up the old drum and haul it away as scrap. The only thing that we are interested in keeping would be the gear that is around the drum. It has the same pitch diameter as our new drum, and even though it mounts completely differently, in a pinch (catastrophic failure of our current gear) we could adapt it to be used on our new drum. |
 The new drum has a gear (shown here) that mounts to a flange by means of a bolted connection, where as the old gear mounts to leaf type springs or tongues. In this picture you can also see the upper vat or the walls that will go up the side of the screening section of the drum (the part with the holes in it). These walls were the ones that were too large and had to be modified. |
 The up-side to this outage was that there were no injuries recorded during the duration, but the down side was that the drum keep having failures (as well as other equipment in the mill that was worked on) and we keep having to take down time to fix problems that should have been addressed during the outage. The vast majority of problems are related to small details that get overlooked. If they had been addressed properly they would have taken maybe an extra hour to fix, instead they ended up causing days of down time along with multiple hours of overtime to get them fixed properly. |
 Once the drum was operational, the first major problem was in the gear. First the alignment of the gear didn't go well. The gear was 0.120" out of square to the drum (due to the flange that the gear mounted to was out of square to the drum). This problem could be fixed with shims under each bolt (a different thickness of shim under each bolt to get the drum square), but that would have taken about another 2 days to fix, so we ran it as it was. |
 The gear is made up of 14 segments that bolt together by the means of 6 bolts. Each segment is then bolted to the flange by 9 bolts. Just after start up, one of the flanges started to come apart, and when I took a look inside of the girth gear guard, I found that 3 of the 6 bolts out of one flange had come loose (apparently the one flange was not torqued to specs), and one of then ended up landing just right in the pinion gear and went through the gear mesh, damaging the pinion and the girth gear. Not to mention destroying the bolt. So far we have not yet cleaned and inspected every tooth of the gears to determine the extent of the damage but will on 7-1-08. |
 Then once the damaged has been assessed, we will determine the next game plan as to how to fix it and move forward. After we put some new bolts back in, the thrust roller that keeps the drum from walking down hill (remember that it is on a 1 degree slope) seized up. After taking it apart the bearings that were installed were installed without grease. Apparently, if you don't grease your bearings, they will last approximately one week. Once the roller seized up it started sliding long the face of the support ring and made a little mess. Again, one more thing that will need to be addressed down the road. |
 I am sure that there were more problems of a significant magnitude, but these are the ones that I have pictures (and souvenirs ) of. As much fun as this project has been, I am really looking forward to being able to return to a normal work schedule (although it has not as of yet happened). (this picture is of the thrust roller [now upside down] notice that the outside diameter [that rides on the support ring] is not exactly round anymore). |