Better use of plate coolers to extend their life

The thin plate cooler is composed of many stainless steel thin plates with corrugations on both sides. The two sides of each thin plate introduce the wort and refrigerant water to be cooled (low temperature water, alcohol water, etc.). Due to the relatively large heat exchange area of the thin plate, the corrugated shape of the thin plate is conducive to the formation of intense turbulent flow. So, the cooling effect of this cooler is very good.

 The working principle of thin plate cooler 

Thin plate coolers are divided into several types according to the heat exchange area and the shape of the corrugation of the plate surface. There are closed rubber gaskets bonded with special glue on the outer edge of each thin plate and in the grooves of the inlet and outlet. The gap between the two plates flows down to form a thin laminar flow, and heat exchange is carried out across the corrugated plates to achieve the purpose of cooling the wort.

1.Preliminary preparation attention

Before wort cooling, the wort side of the thin plate cooler and the wort pipeline must be washed and sterilized with hot water above 70°C or by pumping circulation, and the sterilization time should not be less than 30min. After the cooling starts, wait until the wort has drained the remaining water in the equipment, and then let the cold wort enter the yeast adding tank (a three-way valve and a glass observation photo can be installed at the outlet of the thin plate cooler to facilitate the operator's observation and switch).

2.Use caution

During the cooling process, the temperature of the cold wort should be controlled within the range of ±0.5°C of the temperature specified in the process, and there should be no large fluctuations, especially when the cooling is nearing the end, the wort flow is significantly reduced, and the cooling water should be reduced accordingly. flow to prevent a sharp drop in wort temperature. When the wort cooling is completed, a certain amount of water should be fed to drain the wort in the equipment and the pipeline, and the operator can switch according to the observation of the glass observation cover.

3.Equipment maintenance

①The sheet should be removed and washed regularly, generally once a week, because the cold coagulation, hop resin and other substances in the wort will adhere to the sheet on the side of the wort due to cold precipitation, which will affect the heat transfer effect.

②After the thin plate is removed, it can be soaked in 1%~2% dilute lye solution, then use a brush to clean the dirt, and rinse it with clean water. When loading the sheet, check whether the rubber gasket of each thin plate is complete and whether it has fallen off. If the gasket is found to be aging or falling off, it should be replaced or repaired in time.

③ The sheets should be arranged in the order of the numbers of the sheets, and the pressed sheets should be checked according to the specified spacing requirements. The upper and lower ends should be consistent, and should not be too loose or too tight. In order to ensure continuous production, it is best to have a set of spare pieces for exchange.

4.Notes on small details

①Refrigerant water of sheet cooler should use ice water or alcohol water (common tap water or deep well water can be used for cooling in two stages), and salt water should not be used, because the chloride ion of calcium chloride in salt water has a corrosive effect on stainless steel sheet, which will cause corrosion to stainless steel sheet. It will affect the service life of the thin plate. In addition, if the thin plate is not installed properly, the phenomenon of salt water leaking into the wort will also occur, which will affect the quality of the wort.

②The pressure on both sides of the thin plate should be kept as balanced as possible, and the pressure difference should not be too large, otherwise it is very likely that the phenomenon of "channeling" will occur due to the poor installation of the thin plate, which will cause the cooling water to penetrate into the wort and affect the quality of the wort.

③It is better to install an automatic temperature recorder on the outlet pipe of the thin plate cooler. The division value of the recorder requires that each scale be 0.5℃ to effectively control and check the cooling temperature of the wort.

④After each cooling, wash the wort side of the thin plate cooler with hot water to take away the solids or other residues on the thin plate. The room where the thin plate cooler is placed should be kept clean, the floor should be washed frequently, and sterilized regularly to ensure the sanitary conditions of the cooling room.

5.Cleaning attention

Most modern CIP systems are used as special equipment for cleaning pipes, pots and tanks. Thin plate coolers can also be cleaned by the circulating cleaning method of the CIP system.

① The time for dismantling and washing the sheet can be extended to a quarter or half a year.

②The water quality used for refrigerant water has certain requirements. Whether it is alcohol water or low-temperature water (2°C), water with temporary low hardness and low iron ion content should be used (especially when this type of water is recycled as brewing water). ), otherwise it is easy to form scale on the refrigerant water side of the thin plate, which affects the heat transfer effect and is not easy to clean.