Simultaneously controlled steam shower and vacuum apparatus and method of using same

A method for controlling the temperature of a web to be formed into paper comprising steps of

• causing the web to travel on a forming fabric endless belt substantially in a plane in a paper making machine, between a steam apparatus, said steam apparatus disposed over said belt directing a supply of steam directly onto an upper surface of the web;
• said steam apparatus comprising steam supply manifold and a steam chamber interconnected by a feed pipe, a lower wall of said steam apparatus forming a bottom wall of said steam chamber, said lower wall defining a plurality of impingement nozzles spaced in a direction of travel of said belt, and disposed proximate said upper surface of said web, said impingement nozzles being uniformly spaced from said web, said lower wall further defining at least in part a Coanda nozzle, said Coanda nozzle being disposed proximate a forward edge of said steam apparatus and being configured so as to direct steam forwardly therefrom parallel to said belt and in a direction opposite to the direction of travel of said belt;
• and a vacuum apparatus for withdrawing the supply of steam, said vacuum apparatus being located opposite and directly beneath said apparatus for applying the steam and beneath said belt;
• said vacuum apparatus having a vacuum chamber underlying all of said steam chamber and extending beyond said steam chamber forwardly and rearwardly of forward and rearward walls of said steam apparatus, said vacuum chamber being defined in part by a planar upper surface parallel to, and separated from, said steam apparatus lower wall and thereby uniformly proximate said nozzles, and
• simultaneously controlling the steam supply apparatus and said vacuum withdrawal apparatus, by increasing the withdrawal of the vacuum chamber opposite the steam supply as the opposite steam supply application is increased.