Paper Mill Bubble-Up

Reducing Web Breaks and Sheet Defects:

One of the most difficult deposit control problems is the elimination of deposits that form in the approach piping. While system boilouts effectively remove minor deposits from the white water loop and thin stock system, it rarely is effective at removing heavy deposits in the approach flow. Stock system cleaners and pressure screens can effectively remove contaminants and stock lumps in the stock flow, but any deposits that have accumulated in the critical approach piping will often break away during production and cause web breaks or sheet defects.

A PaperMaker’s Tool Since 1961:

In 1961, DuBois introduced a papermaker’s tool to quickly and cost-effectively eliminate post-pressure screen deposits. Many papermakers have used the Bubble-Up® procedure followed by a typical system boilout to completely clean the process flow loop.

Paper Mill Bubble-Up®

The DuBois Bubble-Up® is a unique proceduredeveloped by DuBois for cleaning approach flow piping. The Bubble-Up® targets the "pressure screen to forming table" area in a zero energy state procedure to effectively remove deposits, thereby improving machine runnability and paper quality.

The procedure consists of pumping a concentrated DuBois cleaning solution into the approach piping and then agitating it with air, causing the bubbling action to occur. This is a zero energy state process, with air as the motive of force. The scouring action of the bubbles contacts the entire circumference of the piping and sweeps away the deposits. Effective forming fabric cleaning can also be obtained by opening the slice and allowing the concentrated foam to travel with the crawling forming fabric. The result is improved cleaning in less time than conventional boilouts!