Today in 1978, US Patent 4094445 A was issued, an invention of James Bevan, for his “High Speed Beer Dispensing Method.” Here’s the Abstract:
A method is provided for dispensing beer rapidly into a series of containers for mass distribution to consumers at public gatherings such as stadiums, race tracks, etc. The beer is contained in kegs and is supplied to a multi-tap dispenser through a refrigerated supply line. A coolant is circulated around the beer in the supply line and in the dispenser for cooling the beer. The temperature of the beer is maintained sufficiently close to its freezing temperature as to permit pouring from the taps while preventing excessive foam from being generated in the containers as the beer is poured. Preferably, the beer is maintained at less than 34° F and preferably within about 1/2°-2° F of its freezing temperature which is approximately 28° F for most beer. The pressure drop in the beer supply line is also controlled in order to avoid excessive agitation of the beer.
Makes sense for lager-swill, but I never knowingly saw such a setup (probably because the corp concessionaires in the large venues didn’t care or their beancounters nixed the idea).