This section is from the book "A Treatise On Beverages or The Complete Practical Bottler", by Charles Herman Sulz. Also available from Amazon: A Treatise On Beverages.
The interior of the apparatus is the ice receiver. At the bottom rests the cooler F, which consists either of a coil or a few cylinders. Through this the carbonated water runs on its way to the faucets, or remains there at intervals. Both the ice receiver and the cooler, serve an important purpose. They retain the amount of carbonic acid gas desirable and necessary for the compound of the beverage, which otherwise would escape through the draught arms as soon as opened. The proper cooling of the liquids is a highly important feature of the dispensing trade. It is obvious that the cooler also requires a close scrutiny. On top of the cooler comes the ice; the first requirement is, therefore, that it be of sufficient strength to resist the pressure of the ice, even when rudely thrown in.
All coil coolers are made of solid block-tin, the cylindrical coolers are made of copper (iron or steel cylinders would rust), and must be carefully lined inside with sheet block-tin, seamless, just like a fountain, to prevent any metallic contamination. They must be of such a form and placed in such a position as to secure the maximum of refrigeration with the minimum amount of ice. Only small cylinders should be employed if no coils are used. If they are of large diameter the inner portion of its contents would be but little affected; if of greater length, more ice must be used to keep it covered.
Fig. 332. - Coil Cooler.
Fig. 333. - Cylinder Cooler.
Between the pipes of the coil cooler, or between the different small cylinders of a cylinder cooler, must be sufficient space for the iee to melt in, or for the dripping ice water to wash all sides of the coolers. Use small pieces of ice in the ice chamber and place the coarser lumps on top, as it packs closer and cools better. The interior of the apparatus should be washed out at least once a week, and thoroughly cleansed from the sediment deposited by the ice. This is a very important matter, and, if attended to, effectually preserves the apparatus, besides keeping it clean and sweet, care being necessary to keep the waste pipe unclogged and run out the drip and refuse. If it should get stopped up at any time, blow through it. Where small portable fountains are used and circumstances permit, the cooler can be dispensed with and the fountain itself put in an ice box and surrounded with ice.