What is the typical pressure in exhaust pipes? Is there anyone with practical experience?
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The exhaust gas is collected under negative pressure and sent to the exhaust gas treatment unit, which contains a fan; what are the pressures generally on the front and back of this fan? I’d like to ask those with experience.
The pressure in exhaust ducts depends on various factors, including duct length, diameter, fan type, and type of exhaust gas. Normally, the pressure in front of the fan is negative, ensuring that waste gas is drawn into the treatment system ； The pressure behind the fan may be positive, pushing the treated gas out. The specific value may range from several dozen to several hundred pascals. In actual installation, it is necessary to refer to the design parameters of the fan and the system to make decisions. .
This post was last edited by CHANGBAISHI on 2024-3-30 06:57. Relevant process parameters should be included, such as pressure, flow rate, temperature, as well as the physical and chemical properties of the waste gas – whether it is flammable, explosive, toxic, etc., for reference.
It depends on whether it is exhaust gas from storage tanks, exhaust gas from loading processes, or exhaust gas from sewage collection tanks. Generally, the inlet pressure of the fan is around -2 kPa to 10 kPa, while the outlet pressure is usually 10 to 20 KPa (an increase of 10 kPa)
Negative pressure collection of exhaust gases is an effective method for exhaust gas treatment; it uses negative pressure to guide the exhaust gases from their source to the treatment equipment, ensuring that they are properly processed. In this process, the fan plays a crucial role, providing the necessary power to maintain a negative pressure condition. Regarding the pressure before and after the fan, it actually depends on various factors, including the characteristics of the exhaust gas source, the layout and resistance of the piping system, the requirements of the treatment equipment, as well as the type and performance of the fan. Therefore, it is difficult to provide a specific numerical range. Generally, in a negative-pressure exhaust gas collection system, the pressure before the fan (i.e., the pressure at the source of emission) is usually positive or slightly above atmospheric pressure, while the pressure after the fan (i.e., the pressure at the inlet of the treatment device) is negative. The function of the fan is to overcome the resistance in the piping system and guide the exhaust gas from the positive-pressure area to the negative-pressure area. To determine the specific pressure values before and after the fan, detailed system design and calculations are required. This usually involves measuring the flow rate and pressure at the exhaust emission sources, assessing the resistance and losses in the piping system, and selecting the appropriate type and specifications of fans. During the design and operation phases, factors such as the fan’s efficiency, noise level, and maintenance requirements also need to be taken into account. Therefore, for a specific exhaust gas negative pressure collection system, it is recommended to consult professional engineers or designers for a detailed evaluation and design to ensure the effectiveness and safety of the system.
For the first few tens of kPa, the pressure increase to be applied depends on the back pressure and the requirements of the processing process
The inlet of the fan is usually under negative pressure; in a project I worked on previously, the pressure at the fan inlet was -0.0784 kPa. As for the outlet pressure, it depends on the fan’s pressure head, which is around 10 thousand pascals, though this varies from one fan to another.