—Beginning at shell and tube coolers the brine passes into supply pipes which decrease in size as they approach the ends. The return line tapers in opposite direction. The pressure carried is only sufficient to make a sufficiently rapid circulation.
A small pump is inserted in the line so that the pressure can be increased on that portion through the spray nozzles. This lessens the power over carrying the entire system at a high pressure.
The balance tank is located at such point as will best serve to collect the brine from closed coils and the return from the spray coolers. A vacuum valve is put on the closed line to prevent siphon.
A return connection to the main pumps is made, and also connections to the concentrator from balance tank so that a portion of the brine can be concentrated.
This system requires more concentration than the closed system. It has the advantage that coolers can be used as sharp freezers if insulation be proper.
Closed System.
—Beginning at shell and tube coolers the discharge mains and piping are the same as for the open system. Return mains as indicated. Balance tank is located elevated above upper coils.
A localized defrosting system is installed with individual pump circulating brine over coils, continuously as required. The collecting tank is located as near as convenient to lessen pumping head. The brine flowing over coils in the lofts is concentrated to a strength equal to circulating brine and introduce into circulation replenishing brine for defrosting from mains. Concentrator is located where suitable.
In using closed coils the arrangement is different for beef and hogs so as to assist in the circulation for hog cooler with a view to producing uniform temperatures.
