How to use steam correctly in a factory

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How should a factory use steam properly? How should a plant make correct use of steam? The factors that affect proper steam technology are quite complex, as they relate to the requirements for various stages such as steam generation, transmission, heat exchange, and waste heat recovery. Proper use of steam technology requires that every aspect of the steam system’s design, construction, maintenance, upkeep, and optimization be carried out in a proper and lawful manner. Watt Energy Saving’s experience over the past 40 years shows that most customers have great potential for improvement and numerous opportunities. A good steam system can help steam users reduce energy waste by 5–50%, which holds significant economic and social value. The steam reaching the point of use should have an adequate volume, the correct pressure and temperature, be free of air and non-condensable gases, be sufficiently clean, and remain dry. The correct quality means that the steam usage point must receive the right amount of steam, which requires accurately calculating the steam load and then selecting the appropriate steam delivery pipes. Correct pressure and temperature: Steam reaching the point of use must have the correct pressure; otherwise, its performance is affected. This is also related to the proper selection of pipes. This pressure is based on the design standards of the heat exchange equipment and the heat exchange requirements; insufficient pressure can lead to a reduction in production efficiency. And excessively high actual steam pressure can cause safety and stability issues. A pressure gauge can only indicate pressure, but it cannot reveal everything. For example, when steam contains air and other non-condensable gases, the actual steam temperature is not based on the saturated temperature at the pressure corresponding to the steam table. When air is mixed with steam, the volume of the steam becomes smaller than that of pure steam, which means a lower temperature. Its effect can be explained by Dalton’s law of partial pressures. For a mixture of air and steam, the total pressure of the gas mixture is the sum of the partial pressures of each component gas in the entire volume. If the pressure of the mixture of steam and air is 1 barg (2 bara), and the pressure gauge shows 1 Barg, then in reality the steam pressure used by the steam equipment at that time is below 1 barg. If the equipment in question requires 1 bar of steam to achieve its rated output, then it is certain that this requirement cannot be met at that time. In many chemical processes, there is a minimum temperature threshold required to achieve chemical or physical changes. If steam carries moisture, it reduces the heat content per unit mass of steam (evaporation enthalpy). The steam should be kept as dry as possible. In addition to reducing the heat per unit mass, the moisture carried by steam increases the thickness of the water film on the surface of the heat exchanger, thereby increasing the thermal resistance and reducing the performance of the heat exchanger. There are many sources of impurities in steam systems, such as particles carried from the boiler water due to improper operation of the boiler, pipe scale, welding slag, and materials used for pipe connections. All these impurities affect the operational efficiency of the steam system. This is because the treatment chemicals from the boiler accumulate on the surface of the heat exchanger, thereby reducing heat transfer. Pipeline impurities and other foreign substances can affect the operation of control valves and steam traps. To protect these products, filters must be installed on the pipelines. Using a pipe filter cannot eliminate the impact of substances carried in the boiler water. The design of the steam system’s drain valves and the drainage of condensate must ensure the continuity and stability of heat exchange. Select the appropriate type and size of steam trap to design a trap system that can discharge condensate smoothly under any operating conditions. Reliable recovery of condensate can save more than 10% in steam consumption and enhance the reliability of steam system operation.