Flash or Foul, 2008 Engineering, Pulping and Environmental Conference
ARE YOU A TAPPI MEMBER? TAPPI members have exclusive, FREE access to technical conference papers and presentations six months after the conference in TAPPI's e-library. The e-Library offers:
- Unlimited access to more than 18,000+ documents
- Fast, robust search engine for fast search results
- Members get FREE access to conference proceedings, TAPPI JOURNAL articles, Paper360º articles, archived Solutions! articles, and much more
- View thousands of technical paper abstracts
- Ability to search by keyword, title, author, events or industry segment
*Technical papers and presentations are available for sale immediately following the conferences before the 6 month embargo period.
Please Note: This document will be available in PDF format in the "My Electronic Documents" link on the home page once your order has been completed. Please make sure you have the latest version of Acrobat Reader. Click on the Acrobat Reader icon to check for the latest version, it’s FREE. To print a hardcopy of a PDF file correctly you must have a postscript printer. If you are not sure if your printer is a postscript printer please refer to your owner’s manual.
Condensate stripper preheater fouling is a significant problem in the pulp and paper industry. Fouling reduces energy efficiency, increases maintenance costs for cleaning, and lowers availability in condensate stripping systems. High condensate stripper availability is needed to comply with environmental regulations. The preheater is often the major cause of downtime in condensate strippers. Many types of heat exchanger designs have been used as preheaters, including plate-and-frame, shell-and-tube, and spiral heat exchangers. All of these designs have been plagued by the reaction-type fouling that occurs on both the foul and the stripped condensate sides of the exchangers. A new preheater design was developed and implemented at the Charleston mill. It consists of a series of flash tanks and shell-and-tube heat exchangers. Stripped condensate is cooled by flashing in the flash tanks, and the flash steam is used on the shell side of the shell-and-tube heat exchangers. The flash steam is clean and does not cause the shell side fouling that occurs when condensate itself is used on the shell side. The foul condensate is heated in the tube side of the exchangers, and results in fouling that is easily removed by chemical cleaning. The preheater avoids the high temperatures on heat exchanger surfaces which promote chemical reaction-type fouling. The new preheater was installed in 2006 in the Charleston mill condensate stripper system, which has a flow rate of 3.8 m3/min and a bottoms temperature of about 150 °C. It has performed well and has resulted in excellent preheater availability.