In the process of beer production, the cooling consumption of hot wort cooling water is quite large, accounting for about 50% of the total cooling consumption of the entire beer production. The cooling equipment is composed of many thin plates with grooves on both sides, and a group of two is a basic unit. When the wort is cooling, the hot wort and the cooling medium flow countercurrently along the grooves on both sides of the grooved plate in the form of turbulent flow through pumping to exchange heat. There are mainly two ways, namely two-stage cooling method and one-stage cooling method. The two-stage cooling method was the most common in the past, but now the one-stage cooling method is being used more and more.
The traditional cooling process is two-stage cooling: an intermediate plate is installed between the two stages. The first stage of cooling is to use tap water as the cooling medium to cool the wort from about 95°C to 40-50°C, and the cooling water is heated from nearly 20°C to about 55°C; the second stage of cooling is to use deep cooling refrigerant (ethanol or ethylene glycol solution) as the cooling medium, the wort is further cooled to about 7°C in the fermentation tank, the refrigerant is heated from -4—-3°C to about 0°C, and returned to the refrigeration station for recooling and recycling. The water after heat exchange in the previous stage can be used as feeding water.
One-stage cooling method: This method uses a cooling medium to cool the hot wort (about 95°C) to the yeast inoculation temperature (about 7°C) at one time. The cooling medium is brewing water, which is first cooled to 2-4°C (commonly known as ice water) by ammonia direct cooling, and heated to 75-80°C after heat exchange with hot wort. This water can be directly used as washing water use.
Comparison of the two methods Compared with the two-stage cooling, the one-stage cooling method has the following advantages.
1. The first-stage cooling method is simple in equipment and does not require an intermediate plate. The cooling medium is brewing water, without the use of ethanol or ethylene glycol. The volatilization and consumption of auxiliary materials are avoided.
2. The two-stage cooling freezer should keep the refrigerant at -4~-3°C, and bear the heat load of the wort from 40~50°C to about 7°C; the one-stage cooling freezer should bear the cooling water from normal temperature to 2~4°C heat load. Compared with the two, the one-stage cooling method can save electricity by 30% to 40%.
3. The outlet temperature of the cooling water in the first stage of the two-stage cooling is about 55°C, and it needs to be heated if it is used for washing the grains; the outlet temperature of the brewing water in the first stage of cooling is just suitable for washing the grains. Its thermal energy is fully utilized.
4. The temperature of the two-stage coolant is variable in the middle of the cooling process, which is very unstable. The basic parameters of the hot and cold medium remain unchanged during the one-stage cooling process, and the operation is stable and easy to control.
August 21, 2023
In the process of beer production, the cooling consumption of hot wort cooling water is quite large, accounting for about 50% of the total cooling consumption of the entire beer production. The cooling equipment is composed of many thin plates with grooves on both sides, and a group of two is a basic unit. When the wort is cooling, the hot wort and the cooling medium flow countercurrently along the grooves on both sides of the grooved plate in the form of turbulent flow through pumping to exchange heat. There are mainly two ways, namely two-stage cooling method and one-stage cooling method. The two-stage cooling method was the most common in the past, but now the one-stage cooling method is being used more and more.
