Where are liquid ammonia tanks usually stored, and are safety measures necessary?
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As the title suggests, what is the typical concentration of liquid ammonia, and are there any safety concerns associated with it?
@ckwcba, an expert in liquid ammonia, please provide an explanation~
The concentration of liquid ammonia used as a refrigerant is generally above 98.5%. Liquid ammonia is a colorless liquid with a strong, pungent odor. Liquid ammonia is usually stored in pressure-resistant steel cylinders or tanks, and it must not be stored together with substances such as acetaldehyde, acrolein, and boron. Liquid ammonia is corrosive and volatile, so the incidence of chemical accidents related to it is high. If ammonia comes into contact with the skin, it can cause chemical burns, which should be treated as thermal burns: adequate fluid replacement, administration of painkillers, maintenance of body temperature, and covering the affected area with a sterile pad or clean sheet. If skin comes into contact with high-pressure liquid ammonia, be careful of frostbite. A storage volume of liquid ammonia exceeding 10 tons constitutes a major hazard source; even if it is below 10 tons, it still needs to be treated as a critical facility. The safety requirements are quite strict – ammonia detectors, ammonia alarm devices, occupational health monitoring, and personal protective equipment are all necessary. It’s quite complicated, and local safety authorities also need to carry out thorough monitoring and inspections
Anhydrous liquid ammonia always has a purity of over 99.5%
Anhydrous liquid ammonia always has a purity of over 99.5%
Several key points for storing liquid ammonia: 1. Liquid ammonia tanks are designed based on their saturated vapor pressure at 50°C; to prevent overheating, a condensation device is required； 2. A certain gas space must be maintained inside the tank; the filling level should not exceed 85% of the tank’s capacity ； 3. Liquid ammonia is a flammable substance under certain conditions; liquid ammonia tanks must be electrically grounded ； 4. The location of the liquid ammonia tank must be well-ventilated to prevent ammonia from accumulating ； 5. The liquid ammonia storage area should have reliable fire access routes and emergency fire water tanks, as well as mobile spray nozzles ； 6. Motors and electrical equipment in the tank area should be of explosion-proof type.
Could you provide the relevant equipment layout diagram?
The equipment layout should be determined based on the specific conditions at the site, but certain key requirements must be met. The discharge duct of the safety valve must also be connected to a safe location, usually an ammonia absorption tank, as ammonia is soluble in water.
A screenshot of a diagram from your project will do; it’s mainly to understand what you have in mind
As the title suggests, what is the typical concentration of liquid ammonia? It depends on temperature: it’s higher at lower temperatures and lower at higher temperatures; around 600 kg/m3 I guess. Liquid ammonia is a Class B hazardous material, so safety considerations must definitely be taken into account. The main codes referenced at present are the petrochemical codes and construction codes. There are also standards set by various industries themselves. But mainly, the above two specifications are referred to.