Hot water heating boiler is one of boiler types which is classified based on use. This boiler is utilized in the heating system to heat water at certain temperature and the hot water is distributed to the expected location. Hot water heating boiler in a house will help convenience especially in the winter season. The heating process is made of piping, pump, and boiler.
Hot water heating boiler based on its capability to heat water at certain temperature can be categorized into three types:
- Low temperature hot water heating boiler - this boiler can operates and heat water until temperature 95o C.
- Medium temperature hot water heating boiler - this type of boiler can perform and increase temperature of water range 95o - 120o C
- High temperature hot water heating boiler - this boiler type is used to heat water until temperature above 120o C.
For medium temperature type and high temperature type, because of its temperature, water lead to change its phase to be steam. It must be prevented by applying pressure to the boiler system. There are several methods to generate pressurized hot water heating boiler as follow:
Nitrogen pressurization method – this method uses nitrogen that is compressed in a vessel tank and distributed together with water as shown in Figure 1 below.
Figure 1: Nitrogen Pressurization Method
Air pressurization method – this method is same with nitrogen pressurization method, the difference is the medium, in this method uses air as the medium.
Diaphragm air pressurization method – this method uses compressed air as above method but it uses diaphragm of neoprene as shown in Figure 2 below among water and air.
Figure 2: Diaphragm Air Pressurization Method
Pressure pump method – this method uses pump to produce pressure in the hot water heating boiler system as shown in Figure 3 below.
Figure 3: Pressure Pump Method of Hot Water Heating Boiler
(Source: Book-The Boiler Operator Handbook-NIFES-Graham & Trotman)