a central rod 30 which is welded or otherwise fastened to the interior of header 25 at 33 the baffles employed may be any design of lateral obstruction to prevent a central core of liquid from flowing rapidly through header 25 from inlet to outlet in the drawings of this invention there are shown baffles comprising a central disk 41 supported by a plurality three in this instance of spaced legs positioned approximately at equal angles to each other plate 41 can be pierced centrally with a drilled hole 43 as shown in fig4 so that it may slide over central support rod 30 and be positioned wherever desired in the length of header 25 first baffle 31 need not be pierced centrally with a hole but can be fashioned to receive the end of support rod 30 in a central clearance 44 formed by the interior ends of spacer legs 42 preferably each of the baffles 31 and 32 is welded to rod 30 to maintain it in its selected position wash water passing through the interior of header 25 enters cover or deflecting shield 34 through a plurality of spaced passageways 37 through the wall of header 25 preferably deflecting shield 34 is placed on the top of horizontally positioned header 25 and therefore passageways 37 can be a series of holes aligned generally.