Application issues of using high-temperature steam to directly heat water
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The factory is being renovated, with the intention of using high-temperature steam to heat the water supply. The existing equipment’s water tank is of an open type, and the pipes in the water are designed as diffuser pipes with small holes; the air inlet for the equipment is located below the horizontal level. Which arrangement for the steam inlet pipe shown in the diagram would be more suitable, in order to minimize water hammer effects? Or neither works; what needs to be improved. I’m not from the chemical industry and am a complete beginner; I hope experts can give me some guidance.
1. High-temperature steam is not suitable for being directly introduced into water to heat it. 2. Check valves are useless in this case. 3. Water hammer does not occur in this type of process
I basically agree with the view expressed in post 2. 1. Using high-temperature steam to heat hot water directly is a waste of energy – high energy being used for little purpose. The high-temperature condensate from other steam heat exchange equipment can be used to heat the water, of course first it is necessary to determine the amount of hot water required as well as its temperature. 2. It is pointless to install a steam trap in the pipeline that carries hot water, as the steam pipeline is under pressure and contains only a limited amount of water; even if there is some water present, it will flow into the tank that needs to be heated. 3. When steam is added directly to water, it will condense immediately; there will be no bubbles forming as when heating water, and no water hammer effect will occur.
If I supply steam with adjusted pressure and low temperature to heat the feed water, with the inlet pipe located below the water level, won’t this result in backflow of water and water hammer? Because I’ve seen similar posts on forums that mention water hammer occurring, so I have doubts?
If I supply steam with adjusted pressure and low temperature to heat the feed water, with the inlet pipe located below the water level, won’t this result in backflow of water and water hammer? Because I’ve seen similar posts on forums that mention water hammer occurring, so I have doubts?
This post was last edited by Rely on oneself in everything_LWTF on 2019-6-11 17:07. If the liquid level in the tank is high, the phenomenon you described will occur. For example, if the tank is 11 meters deep and the liquid level is at 10 meters, with the steam pipeline located at the very bottom of the tank, the water pressure will be 0.1 MPa. In such a situation, if the steam supply pressure is ≤0.1 Mpa, water hammer and backflow will occur. But in reality, the steam supply pressure is relatively high, and it exceeds the pressure difference due to the liquid level. There are basically no issues with water hammer or backflow.
If it is a small hot water tank that is not used very frequently, it is sufficient to connect the steam pipeline directly to the tank in order to heat the water； If hot water needs to be maintained continuously and the temperature is easy to control, it is recommended to use a steam static mixer
…………The water pressure of 1 MPa on the 7th floor should be around 0.1 MPa, right?………… A steam trap isn’t necessary. If a constant water temperature is required, the steam control valve and the water temperature control system can be designed to work in conjunction with each other, which yields good results. Also, keep in mind that the introduction of steam will increase the water volume, so an overflow pipe needs to be considered………… :)
1 atmosphere pressure corresponds to 0.1 Mpa and a water level of 10 meters; 1 Mpa corresponds to a water level of 100 meters. Using low-pressure steam to heat water is an ancient technique – bathhouses in the north likely use steam to warm the water in the baths. If the steam supply is turned off and the temperature drops, the steam inside will liquefy. If there are no leaks, this can cause water to be sucked back in. I don’t think it’s a problem if some water is sucked back in; installing a spring check valve can solve this issue
It’s so embarrassing; it’s 0.1 Mpa:$