What are the main characteristics of water? Water is present in liquid state at normal temperature and has the commonality of general liquids. But compared to other liquids, there are many unique properties. 1 Water in the range of O-4 °C is not thermal expansion and contraction, but cold expansion and heat shrinkage, that is, the temperature rises, the volume shrinks, and the density increases. 2 Among all the liquids, the specific heat capacity of water is the highest, 4.18 J/g·°C. Therefore, water can be used as a high-quality heat exchange medium for cooling, heat storage and heat transfer. 3 At normal temperature (O-100 °C), water can appear solid, liquid, gas three-phase changes, so the use of water phase heat conversion energy is very convenient. 4 In the liquid, in addition to mercury (Hg), the surface energy of water is the largest. 5 water solubility and reaction ability is very strong, many substances not only have great solubility in water, but also have the greatest degree of ionization. The conductivity of water 6 increases with the increase of salt content in water. What are the requirements for water quality in industrial production? Various industrial waters can be divided into direct water and indirect water according to their use. Direct use of water, direct contact with water, product quality, it is very loud, so it requires good water quality; indirect water, generally has no effect on product quality, due to different requirements of anti-corrosion and anti-scaling, but need to adopt different Water quality. (1) Raw material water Raw material water refers to water used as a raw material or as a part of a raw material. In the beverage and food processing industries, water quality has a great impact on product quality. The best water quality should be colorless, odorless, turbid, salt content appropriate, ammonia, nitrogen, nitrite, bacteria and other indicators meet production requirements. Synthetic fiber, electrolysis, medicine, etc. require high quality pure water. (2) Product treatment water refers to washing, bleaching, beating, etc. in the production process, so it also requires better water quality. Its water quality requirements are roughly the same as those for raw materials. Water such as the electronics industry requires high quality pure water. (3) Boiler water due to the high hardness of water will cause scaling in the boiler, resulting in lower boiler thermal efficiency; dissolved oxygen and salts will cause corrosion of boilers and pipelines; HSiOf and alkalinity will cause aeration of steam and water, and affect steam quality . Therefore, the boiler has strict specifications on water hardness, salt content, alkalinity, pH value, HSiOf and dissolved oxygen. (4) Cooling water The function of cooling water is to cool the heat medium, so it is the three major tasks of cooling water treatment to prevent corrosion, scale and microbial damage. Therefore, the quality of the cooling water should be strictly controlled for hardness, suspended solids, dissolved gases, oils and other organic matter, algae and microorganisms. What are the characteristics of atmospheric water quality? Natural rain and snow are formed by condensation of water vapor, so the water quality is relatively pure. Generally, the hardness of rainwater is not more than 70-100 μmol/L, and the salt content is not more than 40-50 mg/L. Because of the exposure to various impurities in the air during the descent process, rain and snow will contain many impurities: for example, in the industrial zone and the vast residential areas, the rain and snow will contain hydrogen sulfide, sulfuric acid, soot and some dust. The coastal area may contain a certain amount of sodium chloride. Precipitation is the best quality water in nature, but it cannot be used as a source of boiler feed water due to difficulties in collection. What are the characteristics of surface water quality? The salt content and hardness of surface water are generally low: the salt content is generally 70-900 mg/L; the hardness is 1.0-8.0 mmol/L. The surface water is unstable in water quality and varies greatly with the seasons. In the dry season of spring and winter, the salt content and hardness are higher, and the turbidity is lower. During the high water period, due to the influence of precipitation, the salt content and hardness decrease, while the turbidity increases sharply. What are the characteristics of groundwater quality? Groundwater is formed by the infiltration or flow of precipitation through the soil and strata, so there are more salts in the water. The salt content is 100-500 mg/L, the hardness is 2-10 mm/L, the suspended matter is few, and the turbidity is low. Groundwater quality is generally stable throughout the year, and seasonal changes have little impact on its quality. Excavator Parts,Excavator Spare Parts,Excavator Engine Parts,Excavator Electrical Parts,Excavator Work Equipment Parts,Excavator Undercarrage Parts JINING SHANTE SONGZHENG CONSTRUCTION MACHINERY CO.LTD , https://www.sdkomatsuexcavatorparts.com
Industrial production requirements for water quality