Installation of water spray cooling system for ethylene oxide storage tanks
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Regarding the design of ethylene oxide storage tanks, codes require the installation of a water spray cooling system. However, if the tank is covered with a foam glass insulation layer, or if internal coil cooling is used inside the tank, or if a jacket cooling system is installed on the outside of the tank, is a water spray cooling system still necessary? In my opinion, it is not necessary, as the internal coil or external jacket serves the purpose of cooling anyway. Moreover, the fluid inside the coil or jacket is chilled water, which has a lower temperature than ordinary cooling water. The storage tank is located under a shelter, preventing direct sunlight from reaching it; therefore, I believe there is no need to install a water spray system in this case. What do the sailors think?
Are you sure it’s just cooling down? It seems that fire suppression is the main function, with cooling serving as a supplementary measure; it depends on the geographical location of the facility. Only in very hot areas in the south might additional spray cooling be necessary.
The exact wording in Document No. 95 issued by the Quality and Technical Supervision Bureau states that ethylene oxide storage tanks should be equipped with water cooling spray systems, and there must be an adequate supply of water available. This water-cooling spray is supposed to be different from fire suppression sprays, right?
This post was last edited by zkbest on 2015-12-8 at 14:15. Ethylene oxide tends to undergo polymerization in the presence of acids, bases, and aldehydes, releasing a large amount of heat； It also releases a large amount of heat when reacting with water. Due to the large amount of heat released by these reactions, which can cause the decomposition of ethylene oxide, acids, bases, aldehydes, water, and other substances must never be present in the storage tanks for ethylene oxide. To ensure the safety of the ethylene oxide storage tank, it is kept at a low temperature of around 5°C using chilled brine, and nitrogen purging is carried out at 0.2 MPa to keep the gas phase composition below the explosion limit. The ethylene oxide storage tank is equipped with water spray protection.
The ethylene oxide storage tank is cooled by a low-pressure brine circulation cooling system with an external jacket. Additionally, a cold water spray system is provided for use in the event of a shortage of chilled brine during shutdown.
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Thank you to this sea friend. It seems that it is necessary to make such arrangements according to the regulations. However, there is an insulation layer around the storage tank, and the water spray can only reach that insulation layer. . . . . ?
This post was last edited by zkbest on 2015-12-9 09:09. So this is also my question: I always feel that cooling plays a secondary role, while safety is the primary concern. I used to work in an ethylene oxide plant; back then we referred to this spray system as fire-fighting water, not cooling water. It also needed to be tested regularly to ensure that it could spray water properly, as it usually didn’t spray any water. The spherical tank in the unit next to us doesn’t have insulation; during hot summer days, water is often sprayed on it for cooling.
Storage tanks with insulation layers and cooling coils do not require an external water spray system; water spraying is primarily required for fire protection purposes
Without insulation, it is understandable to use water spraying in hot summer temperatures; but for systems that come with both insulation and jacket cooling, it seems unnecessary to install a water spraying system. It is still necessary from a fire safety perspective.
Mm-hmm, I also think it’s unnecessary to install a cooling spray system, but then again, what if there’s a problem with the coil cooling system? Is it for double insurance?