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I. Selection and usage of plate heat exchanger for aerated beverage mixer

The solubility of CO₂ in water is greatly affected by temperature. The higher the temperature is, the lower the solubility is and the more unstable it is. This requires the production of gas drinks to be carried out in a low temperature environment, so that CO₂ can be fully, evenly and stably dissolved in water. Because plate heat exchanger has strong heat exchange capacity, his heat transfer coefficient is many times of ordinary heat exchanger, unit volume heat exchange area is also very large, the total volume is small, light weight, therefore, it is widely used in the production of carbonated drinks.

The first considers of food production industry is the hygiene of the equipment used, followed by safety, stability and reliability, and also takes into account the convenience and service life of the equipment in the process of use. Therefore, low and stable temperature is needed in the mixing production process of the carbonated beverage, and the icing and water hammer phenomenon caused by the plate heat exchanger have become problems that need to be considered and overcome.

Ⅱ. Requirements of plate heat exchanger selection

1. Health

The corrugated grooves between the heat conduction plates of plate heat exchangers form liquid channels. The lower roughness Ra value of the channels is, the less the beverage residue is, the easier it is to be cleaned, and the less the heat transfer plates are prone to corrosion. The roughness Ra value should be controlled to 0.8μm.

2. The pressure

The pressure resistance of plate heat exchanger should be more than1.5 times to the operating pressure.

3. Containment

Sealing gasket has double channel overflow sealing groove, if sealing gasket aging or plate deformation caused by leakage, the outflow of media can be found in the first time.

4. The corrosion

CIP cleaning and disinfection of equipment and pipelines are required before and after beverage production. Hot water, hot alkaline water and hot pickling water are generally used for cleaning. Therefore, low or ultra-low carbon austenitic stainless steel such as 304L and 316L are selected as raw materials. At the same time, the rubber material of sealing gasket is also required to be non-toxic and tasteless, and not easy to age in acidic, alkaline and high temperature environment.

5. Good economy

Countercurrent medium flow direction should be selected as far as possible to obtain the maximum temperature difference, improve heat exchange efficiency and improve economy.

6. Less residue

The distance through the beverage as much as possible in the form of parallel, high into low out, reduce the residual amount in the heat exchanger after shutdown discharge.

Ⅲ. Critical control points

1. Prevent icing

If the drink inside the heat exchanger freezes, it is easy to cause the normal operation of the equipment, and even cause damage to the equipment.

Low temperature mixing requires the inlet temperature of the heat exchanger cooling media -4℃ to -8℃, which is easy to cause icing and shutdown, even if the inlet valve of the cooling media is closed, but the low temperature cooling media has entered the interior of the heat exchanger will make the drink ice, in order to prevent this phenomenon, the following methods are generally used:

(1) The medium flow direction of heat exchange in the first stage is designed as retrograde;

The inlet temperature of the beverage is relatively high, while the inlet temperature of the cooling media is relatively low. In order to ensure the outlet temperature and heat exchange efficiency of the second section of the beverage, the outlet temperature of the first section of the cooling media = the outlet temperature of the second section of the beverage -2℃= the inlet temperature of the second section of the cooling media.

2. Prevent water hammer phenomenon

If the mixer is shut down in the working process, the cooling media will flow back to the refrigeration unit through the bypass pipeline. When the cooling media circulation pipeline is cut, abnormal impact load (water hammer phenomenon) is prone to occur, resulting in severe vibration of the equipment and great change of beverage flow rate, which will eventually lead to leakage of the equipment. Our equipment can adjust the flow of the cooling media into the plate heat exchanger, and the excess cooling media will automatically return. This new design can avoid the occurrence of water hammer phenomenon. At the same time, the total amount of backflow cooling media is the flow that can be provided by the cooling unit.

Mature product of Sunswell

Author：Robin