As the name implies, the coolers are used to low the temperature of the milk. Only at this temperature it can be stored for a longer period of time without the risk of adverse reaction in it. This is extremely important, because the quality of milk largely depends on how quickly we are able to cool it down below 10 oC. Remembering the initial milk temperature is 36 oC, it does not have to be a quick process. The sooner this is done, the better the price we will get when selling the product. The bacteriological quality of the milk is also important for the customer. The best bacteriological quality we can get at temperatures around 4o C. Other popular refrigeration systems, which are getting more popular, are pre-cooling systems (in the West they are everywhere). The aim of such an installation is to lower the initial milk temperature before applying it to the cooler. This allows you to reduce the cost of electric cooling of the cooler itself and to increase the speed of obtaining the optimum product temperature. Maybe it is worth considering whether buying such a system will not allow us to get a profit in a really short time.
The coolers can be divided into several types due to their construction: a) open – cheaper when you buy them, but they need manual wash after each use; We can divide them into:
– open with cylindrical structure – open with a bathtub structure b) Closed – the disadvantage is their higher price, although they do not require too much attention, because they have an automatic washer. There are also models with a separate generator that can be placed in a different room than the cooler itself (sometimes there is simply no room for the whole machine so this will help to find the optimal solution); they can be divided into:
– closed cylindrical construction
– closed elliptical structure
Depending on the size of the device, the coolers have different capacities, ranging from 200 l to 3000 l of milk. There are several significant manufacturers of such systems who through a wide range of refrigeration tanks can reach the needs of every customer.
Like any cooling/ refrigeration device, milk coolers are equipped with a standard cooling system. It consists of two energy exchangers (evaporator and condenser), a compressor (which operates as a pump: it increases the pressure and drives the whole system, converts mechanical energy into electricity) and an expansion element (possibly a capillary tube) which causes lowering the refrigerant pressure. All components are connected by refrigeration lines (of course in thermal insulation). Because of the need to power the compressor, we need to place the cooler near the power source. Another important feature of coolers is the material from which the milk tank is made. It should be made of a more expensive and more noble sheet – acid resistant sheet. This necessity, forced by the chemical composition of the milk, significantly increases the cost of the whole device. Another important element is thermal insulation, most commonly made of polyurethane foam or other insulating substance. Thanks to that, the loss of cooling to the environment is significantly reduced. The equipment, added to refrigeration systems as an extra, and being a standard for open-type coolers, is a low-speed stirrer that does not cause foaming or misting of milk; It should be appropriately profiled. Another necessary addition is a thermostat, responsible for regulating the operation of the cooling system and the product mixing system. The users of coolers frequent problem, which is milk freezing, also should not be forgotten. However, manufacturers have found a solution also to this problem. A well-adjusted tank temperature keeping system will not allow such a situation to happen.