Industrial refrigeration equipment - chiller, screw chiller. Low temperature chiller <industrial chiller, chiller selection suggestion: For customers who have used chillers, chiller selection is already a light vehicle, for each requirement criteria It’s all in the heart. For the first time customers who purchase chillers, they may not know too much. They don't know how big chillers to use. So, how do we choose the most suitable chiller for you?
The chiller is a kind of refrigeration equipment that can provide industrial chilled water to various industries to achieve the purpose of cooling. According to different heat dissipation methods, it can be divided into air-cooled chiller and water-cooled chiller, which can control the temperature at 5-35 degrees. Between, and the low temperature chiller can control the temperature between 0 and -40 degrees. When selecting the chiller, we need to know exactly how much the chiller's inlet temperature, the temperature of the effluent, the flow rate, the size of the water tank, etc., and the working environment of the chiller, such as the ambient temperature and the seasonal variation of the ambient temperature. , environmental space, etc.
A high-quality and low-cost chiller is a guarantee of successful engineering design and has a long-term impact on the operation of the system:
1. Cooling water flow rate: refers to the cooling circulating water flow of the chiller to be supplied when the refrigeration equipment is used.
2, cooling capacity: that is, how much cooling capacity is needed, the more commonly used cooling capacity units are Kcal/h, kw, etc.
3, the water temperature: return water temperature or return water temperature difference requirements: the water temperature refers to the required chilled water temperature, the return water temperature refers to the cooling water temperature, some equipment with strict heat dissipation requirements will have cooling water supply temperature requirements.
4, the water pressure: some need heat dissipation equipment due to the complex internal heat dissipation structure of the equipment, there is a certain pressure requirement for the cooling water supply, then it is necessary to consider whether the rated water pressure of the chiller can meet this requirement.
5, the lift of the pump: If it is a one-on-one use of the single machine, the pump lift should not be a problem. If multiple water-cooled chillers are connected in parallel for multiple applications requiring cooling equipment, the resistance of the piping system should be considered to estimate the pump that needs to be configured with a large head.
6, control adjustment requirements: generally refers to pressure control adjustment and temperature control adjustment.
7. Safety requirements for chiller safety protection: A. Compressor delay start protector B. High and low voltage protection function C. Reverse phase protection D. Compressor overload protection E. Anti-freeze protection F. Compressor overheat protection G. Compressor Frequently start the protector and abnormal indicator and various protection switches.
The evaporator is one of the four major components of the refrigeration system and is the ultimate expression of cooling efficiency and efficiency. The evaporator is generally designed by the chiller manufacturer, and the user who chooses it does not have to worry about it. However, in order to better maintain the refrigeration system and ensure its efficient operation, the following points should be noted in the use of the chiller evaporator:
1. The effect of liquid level on evaporation temperature. Due to the influence of the height of the refrigerant liquid column, the evaporation temperature at the bottom of the flooded evaporator is higher than the evaporation temperature of the liquid surface. Different refrigerants have different effects on the evaporating temperature of different liquid levels depending on the height of the hydrostatic fluid. Regardless of the refrigerant, the lower the evaporation temperature of the liquid surface, the greater the effect of the hydrostatic height on the evaporation temperature. Therefore, the effect of the hydrostatic height on the evaporation temperature can be ignored only when the evaporation pressure is high. When the evaporation temperature is low, it cannot be ignored. That is to say, it is uneconomical to use a full liquid evaporator at this time.
2. The possibility of freezing of the brine. If the evaporation temperature is lower than the solidification temperature of the brine, the brine may freeze. In the last process of the brine, the temperature of the brine is the lowest, and the possibility of freezing is the highest. When water is used as the brine, the temperature of the inner wall of the tube can theoretically be as low as 0 °C. However, for safety reasons, the inner wall temperature of the tube at the outlet end of the last process is usually kept above 0.5 °C. In the case of brine as a coolant, according to the same principle, the inner wall temperature of the pipe should be higher than the solidification temperature of the brine by more than 1 °C.
3. Pressure loss of the refrigerant in the evaporator. The pressure loss caused by the refrigerant flowing through the evaporator inevitably causes the pressure p2 of the refrigerant at the outlet of the evaporator to be lower than the pressure p1 at the inlet, thereby lowering the suction pressure of the compressor, resulting in a decrease in the refrigeration capacity.
Dechang Machinery Tips: The box type chiller uses the water tank coil evaporator, the open chiller and the screw chiller use the shell tube evaporator, and the anti-corrosion chiller selects the titanium tube evaporator or the stainless steel plate exchanger. The chiller has different evaporators and can be customized according to customer requirements.
What is Food additive?
Food additives refer to chemical synthetic substances or natural substances intentionally added to food in order to improve the quality, color, aroma, and taste of food, as well as for the needs of anti-corrosion and processing technology. These additives are usually added in small amounts during the food production process to enhance the sensory properties, stability, safety or convenience of the food.
The functional classification of food additives includes but is not limited to the following:
1. Acidity regulator: used to maintain the acid-base balance of food.
2. Anti-caking agent: prevent food ingredients from clumping or aggregating.
3. Defoamer: Reduce or eliminate foam in the food production process.
4. Antioxidants: prevent food oxidation and deterioration, extend shelf life.
5. Bleach: used to improve the color of food.
6. Leavening agent: make the food expand during cooking or baking.
7. Base agent substances in gum-based candies: ingredients that provide a gelatinous texture.
8. Colorants: give food a specific color.
9. Color protectants: Protect food color from oxidation or other factors.
10. Emulsifier: help oil and water and other insoluble substances mix evenly.
11. Enzyme preparations: used to catalyze specific reactions in food processing.
12. Flavor enhancer: enhances or improves the taste of food.
13. Flour treatment agent: Improve the processing performance of flour.
14. Film agent: Form a protective film on the surface of the food to prevent drying or oxidation.
15. Moisture retention agent: to maintain the moisture content of food, affecting its taste and shelf life.
16. Nutritional fortifier: Increase the nutritional value of food, such as adding vitamins or minerals.
17. Preservatives: prevent food from spoilage and extend shelf life.
18. Stabilizers and coagulants: improve the stability of food or make it solidify.
19. Sweeteners: Provide sweet taste and can be natural or artificial.
20. Thickener: increase the viscosity or thickness of food.
21. Edible flavors: Provide or enhance the aroma of food.
22. Processing AIDS for the food industry: substances that play an auxiliary role in the food processing process.
The definition and regulation of food additives may vary from country to country, but in general, their use must comply with relevant food safety regulations and standards to ensure that the specified amount of use will not cause adverse effects on the health of consumers. The Joint Food Regulatory Committee of the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) has also defined and classified food additives.
Food Additive, Health food ingredient, Nutritional Supplements, Dietary Supplements
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