High air and gas contents in pulp suspension create a number of problems in paper, board, and tissue manufacturing, such as foaming, pin holes, web breaks, pulsations, MD variations, as well as reduced drainage and cleanliness. High air and gas contents also affect the paper quality negatively in regard to printability and formation. Therefore, an optimally deaerated stock flow is required for today’s modern, high-speed, and board machines to ensure stable operating conditions.
Modifications to the existing system and wet-end, such as changes in machine speed, capacity increases, and grade or furnish changes may lead to an overload of the white water system. As a result, entrained and dissolved air as well as other gases are built-up and may cause a number of operating problems. Common practice is to add expensive defoaming chemicals to overcome these problems in the short-term.
The installation of a Perivac deaeration system enhances the overall production performance in the long-run.
For many applications, depending on the requirements of the wet-end and the properties of the final product, only partial flow deaeration is needed. This keeps the size of the Perivac deaeration system down and leads to substantially reduced installation and operating costs. The Perivac deaerator is installed to deaerate just the right amount of thick stock and white water to achieve stable production conditions and improved sheet quality.
