The technical indicators of steam are reflected in the requirements for steam generation, transportation, heat exchange use, waste heat recovery and other aspects. Steam technical indicators require that every process of the design, construction, maintenance, maintenance, and optimization of the steam system be reasonable and legal. A good steam system can help steam users reduce energy waste by 5-50%, which has good economic and social significance.
Industrial steam should have the following characteristics: 1. Can reach the point of use; 2. Correct quality; 3. Correct pressure and temperature; 4. Does not contain air and non-condensable gases; 5. Clean; 6. Dry
The correct quality means that the steam usage point must get the correct amount of steam, which requires correct calculation of the steam load and then the correct selection of steam delivery pipes.
Correct pressure and temperature means that the steam must have the correct pressure when it reaches the point of use, otherwise performance will be affected. This is also related to the correct selection of pipelines.
A pressure gauge only indicates pressure, but it does not tell the whole story. For example, when the steam contains air and other non-condensable gases, the actual steam temperature is not the saturation temperature at the pressure corresponding to the steam table.
When air is mixed with steam, the volume of steam is less than the volume of pure steam, which means a lower temperature. Its effect can be explained by Dalton’s law of partial pressure.
For a mixture of air and steam, the total pressure of the mixed gas is the sum of the partial pressures of each component gas occupying the entire space.
If the pressure of the mixed gas of steam and air is 1barg (2bara), the pressure displayed by the pressure gauge is 1Barg, but in fact the steam pressure used by the steam equipment at this time is less than 1barg. If the appliance requires 1 barg of steam to reach its rated output, then it is certain that it cannot be supplied at this time.
In many processes, there is a minimum temperature limit to achieve chemical or physical changes. If steam carries moisture it will reduce the heat content per unit mass of steam (enthalpy of evaporation). Steam should be kept as dry as possible. In addition to reducing the heat per unit mass carried by steam, the water droplets in the steam will increase the thickness of the water film on the surface of the heat exchanger and increase the thermal resistance, thus reducing the output of the heat exchanger.
There are many sources of impurities in steam systems, such as: 1. Particles carried from boiler water due to improper operation of the boiler; 2. Pipe scale; 3. Welding slag; 4. Pipe connection materials. All of these substances can affect the operating efficiency of your steam system.
This is because: 1. Process chemicals from the boiler can accumulate on the heat exchanger surface, thereby reducing heat transfer; 2. Pipe impurities and other foreign matter can affect the operation of control valves and traps.
In order to protect these products, water treatment can be carried out to increase the purity of the water entering the equipment, improve the quality of the water, and improve the quality of the steam. Filters can also be installed on the pipelines.
Nobeth steam generator can produce steam with higher purity through high-temperature heating. When used in conjunction with water treatment equipment, it can continuously improve the quality of steam and protect the equipment from being affected.
Post time: Nov-24-2023
