Today in 1912, US Patent 1015443 A was issued, an invention of Robert Hoffmann, for his “Apparatus for Macerating Wort.” There’s no Abstract, but in the description he explains the problem and his solution:
In macerating they wort in making beer the sparging water has hitherto been poured on to the wort by means of a rotary sprayer spraying over or sparging the wort. As the sparging water falls from a certain height on to the surface of the wort it is not only impossible to avoid unintentionally mixing the wort with the sparging water,’but the latter is also undesirably cooled. Both disadvantages thus involve a loss of yield from the grain and thus mean an incomplete’ working.
Now as compared with the ordinary apparatus for maceration this invention consists in the sparging water not being, allowed to fall from a height on to the surface of the wort but being introduced in layers on to the surface of the wort, so that the grain during maceration is slowly compressed by the sparging water and does not mix therewith.
This improved apparatus consists in other’ words in the sparging water being allowed to flow on to the wort in a continuous stream without first having to fall through the air — on to the surface of the wort.