New dryer design
This first 6-deck jet veneer dryer in the southern pine industry was commissioned late in 2012; it is the 4th 6-deck dryer built by USNR. The Chopin dryer includes 18 drying sections( 144’) long and is heated with thermal oil. Unique USNR-designed pressurized fan shaft seals effectively keep the plant environment exceptionally clean.
The Chopin plant also invested in the proprietary Automatic Dryer Exhaust Control( ADEC) system. ADEC allows automatic control of the total dryer exhaust volume, and ensures efficient production and maximum veneer quality. Cooler Pressure Balance and Veneer Temperature Control work together at the end of the process to ensure uniform temperature is maintained as the veneer exits the dryer, minimize pitch build up and maximize thermal efficiency.( For more information on these features, please see http:// www. usnr. com / about / news / newsletters / MI _ 6- 12-E. pdf.)
Maintaining market momentum
Jonathan Martin was determined to take every advantage of the profitable market conditions, and looked for inspiration to achieve his goal to maintain the company’ s momentum in the market place. Often the largest cost a producer bears when investing in a new veneer dryer is the outage( production down time) required to demolish the old dryer, erect and commission the new dryer in its place. Jonathan
“ I told Alan we had to come up with a way to tear the dryer out and put the new one in in 3 weeks.”
found his inspiration and took his idea to Alan Knokey, VP of USNR’ s plywood and panel products. Jonathan explained.“ We’ ve experienced a very good plywood market for the past 18 months, so one of the major costs is taking that much production( about 1 / 3 of our dry veneer production) out for an extended period of time. I told Alan we had to come up with a way to tear the dryer out and put the new one in in 3 weeks.” He went on,“ I’ ve seen this done with major pieces of equipment in chemical plants. We build it off line, we roll it into place, we hook up the hot oil and electrical, and away we go.” Alan and the USNR engineering team were very excited about this new concept and the challenge it presented.
A new challenge
Clint Spangler, engineering manager for USNR’ s plywood and panel division, was charged with directing engineering efforts for the project. His initial reaction when presented with the idea was,“ That’ s a pretty big piece of machinery but there’ s
no reason that would prohibit us from doing it.” The opportunity was enticing, and he commented,“ Our biggest challenge was designing the dryer in such a way that we would not pull it apart when we moved it into position. Dryers are typically erected in place, so this project involved designing a means of supporting the dryer for the initial assembly, for rolling it into position and for the final positioning.”
Randy Bullion, mechanical engineering manager, designed the rail system the dryer was assembled and transported on.“ The rail system needed to be free of abrupt changes in elevation and width. It was designed using various sizes of beams to account for changes in floor elevation. Structural steel can have variances not only between sizes, but within the same size and weight depending on where and when the beams were produced.”
Game-changing process
A typical new dryer installation can require 18 weeks of downtime; with this new concept the Chopin plant
“ Our biggest challenge was designing the dryer in such a way that we would not pull it apart when we moved it into position.”
In making preparations for the big move, a large winch was mounted to the mill floor to provide the moving force required for the 1 million pound dryer.
4 Millwide INSIDER | ISSUE 3- 2013