Technical Information

2-3. Direct cooling by chiller

This explains the chiller method that directly cools the liquid to be cooled.

Types of direct cooling chillers

A device that is equipped with freezing cycle that circulates refrigerant using compressor to transfer heat and can forcibly cool the temperature of a liquid is called a chiller unit, chilling unit, chiller, etc. (hereinafter referred to as a chiller).
There is also a method of indirectly cooling using circulating water of a chiller via the liquid-cooled heat exchanger introduced in the previous section, but here we will only introduce methods in which the liquid to be cooled is directly cooled by the chiller itself.

①Immersion chiller

As shown in Figure 1 below, this chiller uses a cooling coil that is directly immersed in a tank of the liquid to be cooled. It is often used to cool liquids that contain solids, such as hydraulic oil (wear powder) or coolant (cutting powder, sludge), where a circulation system can cause pipe clogging. While it has the advantage of being simple and easy to install, it also has many limitations, such as low temperature control stability and the need for a certain tank depth and installation space above the tank.

②Direct circulation chiller

As shown in Figure 2 below, this chiller takes the liquid to be cooled directly from the tank and cools it in the chiller body. Its feature is its ease of use; cooling can be achieved simply by inserting the piping into the tank.

(1) oil chiller /coolant chiller
It takes in oil directly from hydraulic oil or lubricating oil tanks, cutting machine coolant tanks, etc. and cools them. It is used for cooling inside tanks that have many restrictions and where an immersion chiller (1) cannot be installed. Small types that are used one-to-one with equipment such as processing machines are the mainstream.

(2) Water tank cooling chiller
This is a water-cooled chiller that circulates cooling water from a tank or underground pit to the entire facility. Many are large enough to cover the entire building, and some can be joined together (modularized) to suit the size of the facility.
They are often used for factory equipment and air conditioning in commercial facilities.