for papermaking operations the length can range for instance up to about 30 feet 9 1 meters an external source of steam is connected to the steam distribution apparatus and excess steam in the form of condensate is removed through a drain 16 which is located on the side of end plate 14 the contour of the front screen panel or plate 18 preferably matches the external shape of the product to which steam is being supplied the concave shaped curvature of front screen panel 18 is particularly suited for apply steam to a roll of material the front screen panel can also have a planar configuration to match the straight run of a moving sheet as further described herein the steam distributor apparatus 10 is separated into a plurality of steam discharge chambers or compartments along the length of the apparatus 10 so that profiling of the steam application can be accomplished for example the amount of steam that enters into the individual chambers can be controlled in response variations in measured properties of the sheet along its cross direction fig1 b and 1c show the arrangement of the steam outlets or perforations 20 that are formed across the entire length of the front screen panel 18 typically the outlets 20 are arranged in a plurality of rows 22 24 and 26 for instance the individual outlets 20 can be circular or have non circular configurations the number and size of the outlets are designed to achieve the desired steam flow rate and velocity the size of the outlets 20 should be sufficiently small to minimize the amount of fibers and other.