10 April 2013:
As we have stated previously, we are going to be taking the ideas developed in this column over the last couple of years and developing them into design practices. This is how it works. We will provide the basic narrative here for one design practice each week. We will keep it open for comments for one month. After that, we will finish it in formal form and offer it for sale at a modest price. Here is where you come in. If you make a substantive contribution to a standard, the organization for which you work will be granted a pro bono license to use that standard with its current issue number for as long as you like. We have had good response so far! Contribute, please.
Cantilevered Dryers (LGM 2013.014.01
Taking into consideration that the dryer section comprises approximately 2/3 of the length of the paper machine, the use of cantilevered dryers would open up a number of new possibilities, not forgetting eliminating frames and bearings on the tending side.
Cantilevered dryers containing longer drive shafts, mean that two bearings could be placed on the drive side of the dryer. The inboard ones would cause a compression load and the outboard ones a tension load.
The full load of the dryers would be transferred to the foundation. However, the load within the structure would be balanced.
These dryers would be truly cantilevered, eliminating frames and bearings on the tending side, no front side machine track or oil system.
Factors to be taken into consideration include:
I. The width of the machine built with these dryers - wider MD cans.
II. Structural changes under the wet end, press section and dry end, making width changes economically practical in the future.
As always, your comments will be appreciated.
Brian Brogdon, Ph.D.
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