What are wet flammable gases and dry flammable gases respectively?
Thread Content
The Code for Fire Protection Design of Buildings mentions wet combustible gases; how are they defined? What’s the difference?
Refer to the provisions note: .3.1 This clause specifies the fire separation distances between combustible gas storage tanks and buildings, other tanks, and storage yards. 1 A combustible gas storage tank refers to a tank used for storing combustible gases such as hydrogen, methane, ethane, ethylene, ammonia, natural gas, associated gas from oil fields, water gas, semi-water gas, producer gas, blast furnace gas, coke oven gas, wood furnace gas, and mine gas. Combustible gas storage tanks are divided into low-pressure and high-pressure types. The geometric volume of low-pressure combustible gas storage tanks is variable, and they come in wet and dry types. A wet-type combustible gas storage tank, also known as a water-tank type gas storage tank, is mainly composed of a water tank, tower sections, a bell cover, and a water seal. The design pressure of gas storage tanks is usually less than 4 kPa. A dry combustible gas storage tank mainly consists of a cylindrical tank body, a movable piston inside the cylinder, guide frame devices, and an elevator. The design pressure of gas storage tanks is usually less than 8 kPa.
Excerpt from this post on the Safety Forum: http://bbs.anquan.com.cn/thread-195971-1-1.html For low-pressure gas storage tanks, a clear difference is that the sealing medium in wet-type tanks is water, while that in dry-type tanks is oil or ester； A wet-type storage tank will rise vertically or in a spiral pattern as the amount of material stored changes, while in a dry-type storage tank, the internal piston moves up and down when the storage level changes, but the tank’s shape remains unchanged. Gas (methane) in coal mines is a flammable gas, and it can be classified as dry gas or wet gas depending on the conditions under which it is formed. Gas generated from coal formation in continental environments is referred to as dry gas, while gas generated from coal formation in marine environments is called wet gas. Dry gas has a lower ignition point, faster ignition speed, and a higher calorific value, while wet gas has the opposite properties.