Kang Jinghui, an evaporator manufacturer, will talk about the snow water purification and recycling process and system containing snow melting agent.
1. Types of snow melting agents
There are generally two categories of commonly used snow melting agents, one is the organic snow melting agent with potassium acetate as the main component, the snow melting effect is good, and there is no corrosion damage, but its price is too high, and it is generally used in important places such as airports;
The other is the inorganic snow melting agent with "chloride salt" as the main component, such as sodium chloride, calcium chloride, magnesium chloride, potassium chloride, etc., which has the advantage of being cheap, only equivalent to 1/10 of the organic snow melting agent, but its corrosion of public infrastructure is very serious. At present, the commonly used snow melting agent belongs to this category, and sodium chloride is used more.
2. The hazards of "chloride salt" snow melting agent for snow melting and snow removal
The main hazards of "chloride salt" snow melting agent snow melting and snow removal are
1. Corrosion of urban infrastructure: the salt water formed by the snow melting agent will cause damage to reinforced concrete structures and bridges, resulting in cracks, spalling, exposed steel bars and rust of concrete components, and salt water will also damage the asphalt pavement, resulting in poor adhesion between asphalt and aggregates, and easy cracking of the pavement;
2. Affect plant growth: the runoff of snow water containing snow melting agent causes salt to remain in the soil, causing damage and death of road and green space vegetation;
3. Polluted water body: snow water containing snow melting agent flows into rivers or lakes, causing water pollution, affecting fish and aquatic plants, seeping into the ground will affect drinking water, high salinity drinking water is harmful to human health, easy to lead to hypertension and other diseases;
4. If the snow water containing snow melting agent is directly discharged into the sewage treatment plant with the sewage, the chloride in the sewage will exceed the standard that the sewage treatment plant can accept and be less than 500-800mg/L, which will seriously affect the sewage treatment effect and increase the cost of sewage treatment.
3. Snow water purification, recycling and recycling process and system containing snow melting agent
Snow water purification and recycling process and system containing snow melting agent, including raw material brine tank, evaporator, separator, crystallization tank, centrifuge, screw conveyor, vibrating fluidized bed dryer, hot air unit, heat exchanger, compressor, water pump, circulating pump, fan and preheater.
Its beneficial effect is: the use of evaporation crystallization process to recover snow melting salt from snow water containing snow melting agent can significantly reduce the harm caused by snow water containing snow melting agent to the environment, and can also effectively reduce its impact on the sewage treatment plant, at the same time, the recovered snow melting salt can also be recycled as snow melting agent to save resources.