Air intakes are an essential component of many industrial plants as they help provide a continuous supply of fresh air to maintain a healthy environment and support various processes. Proper layout and spacing of air intakes are crucial to ensure that the air quality is not compromised and the system operates efficiently.
The first step in determining the layout and spacing of air intakes is to identify the specific needs of the plant or facility. Factors such as the type of processes, the amount of exhaust generated, and the location of the plant are all essential considerations.
Spacing of Air Intakes in Plants
Following points to be considered and based on international project and guidelines.
- A fresh air intake from a safe location is required for buildings and equipment containing electrical equipment or other ignition sources when these are located in areas containing flammable vapors. Failure to provide air that is free of flammable vapors will present the possibility of igniting vapors, resulting in an explosion. Equipment and buildings that require protected air supplies include the following:
- a. Internal combustion engines and turbines
- b. Air compressors
- c. Inert gas generators
- d. Forced draft furnaces
- e. Electrical equipment boxes
- f. Buildings that contain unclassified electrical equipment
- g. Boilers
- The location of air intakes in relation to adjacent equipment must be carefully selected by taking into account prevailing wind direction, probable horizontal and vertical vapor dispersion patterns, and the hazard that results from possible formation of a flammable vapor/air mixture. Locate air intakes a minimum of 7.5 meter above grade when within 15 meter of process units or within 30 meter of process units containing volatile hydrocarbons.
- When air intakes serve large internal combustion sources, such as gas turbines, special care should be taken in sitting the intake to avoid significant reduction in turbine efficiency. Calculation of air intake design should include an analysis of the effect of the intake on surrounding air patterns to ensure that air flow to the intake is above the 7.5 meter minimum level. Air intakes should be located, to the extent practicable, outside any hazardous electrically classified area.
- Where air conditioning equipment is utilized for buildings within 150 meter of hydrocarbon processing plants, features such as gas detection and shutdown, in addition to the location of the air intake, should be considered in order to protect personnel in the building from toxic or nuisance vapors.
FAQs About Air Intakes
-
What is minimum distance between air intake and exhaust?
The minimum distance between air intake and exhaust varies depending on the specific codes and regulations in the area where the building or facility is located. In general, the distance between the air intake and exhaust should be at least 25 feet to prevent the exhaust from being drawn back into the building through the air intake. However, in some cases, such as in densely populated urban areas or industrial facilities, the distance may need to be greater. It’s important to consult with local building codes and regulations to determine the minimum distance required for air intake and exhaust spacing in a specific location.
-
What is the clearance of a fresh air intake?
The clearance required for a fresh air intake depends on various factors, such as the type of building, the location of the intake, and the local building codes and regulations. Generally, the clearance required for a fresh air intake should be sufficient to prevent blockages and allow for adequate airflow.u003cbru003eu003cbru003eAs per the International Mechanical Code (IMC), the minimum clearance required for a fresh air intake is 10 feet (3048 mm) horizontally from any appliance vent or vent outlet, property line, or any source of contaminated air. If the intake is located above the roof of the building, the minimum clearance should be 3 feet (914 mm) above the roof surface or 10 feet (3048 mm) horizontally from any hazardous or noxious contaminants such as exhaust vents or chimneys.
-
Why are air intakes important in refineries?
Air intakes play an important role in ensuring that the air quality inside the refinery is maintained and that the equipment operates efficiently. They also help to prevent the accumulation of hazardous gases in confined spaces, which can pose a risk to workers.
-
What are the common types of air intakes used in refineries?
The most common types of air intakes used in refineries include roof-mounted intakes, wall-mounted intakes, and ducted intakes. The choice of air intake depends on various factors such as the location of the equipment, the layout of the refinery, and the type of contaminants that need to be removed.
-
What are the best practices for designing air intakes in refineries?
Some best practices for designing air intakes in refineries include ensuring that the intake is located away from potential sources of contamination, such as flue stacks and exhaust vents. It’s also important to ensure that the air intake is properly sized to provide sufficient air flow to the equipment and to prevent backflow.
Read All Equipment Layout in Refinery and Plants.