In the process of ventilation duct engineering design, the calculation mainly includes air flow resistance in ventilation duct, pressure distribution in ventilation duct, hydraulic calculation of ventilation duct and uniform ventilation duct.
1. Division of ventilation system
Industrial ventilation systems in different regions have different requirements for air supply and exhaust. When the space is large, there are multiple corresponding air supply and exhaust points. The utility model can be divided into a plurality of air supply and exhaust subsystems. One system is composed of a fan and a connecting pipe, which is convenient for management. The main basis of the system is: if the production process and running time are the same, it is recommended to divide it into one system. If the operating parameters and air handling requirements are the same, it is recommended to divide them into one system. It is not recommended that the exhaust fan be close to the exhaust point, which is a small system away, which will increase the resistance of the exhaust system.
2. Selection of ventilation duct materials
The materials of ventilation pipes mainly include steel plate, metal hose, plastic and rubber hose, fiberboard, plywood, gypsum board, UPVC Plastic board, brick and concrete. Steel plate is a common material for ventilation pipes, mainly because it has the characteristics of corrosion resistance and high temperature resistance, and it is very convenient for processing, manufacturing and installation. Some ventilation ducts technically need to be moved frequently. Such ventilation pipes need to be made of flexible materials, such as metal hose, plastic hose and rubber hose. UPVC Plastic board has smooth surface and convenient processing, but it is not resistant to high temperature. Suitable for corrosive industrial ventilation and exhaust systems.
3. Selection of section shape of ventilation duct
The section shape of ventilation pipe is generally divided into rectangular and circular. When the cross-sectional area is the same, the circular ventilation pipe not only has low resistance and high strength, but also saves pipes. Circular ventilation pipe, small diameter, easy to manufacture and more convenient for heat preservation. However, rectangular ventilation pipes are easier to manufacture than circular ventilation pipes, and the layout is simpler than circular ventilation pipes. Under normal circumstances, when the cross section of the ventilation pipe is small and the flow in the pipe is large, the circular ventilation pipe shall be used. When the section of air duct is large, rectangular air duct shall be adopted to make full use of building space. Rectangular air duct, high air supply ratio close to 1 The effect is good, which can not only save operation energy consumption, but also save investment.
4. ventilation duct layout
The layout of ventilation duct is directly related to the overall layout of ventilation system. Closely cooperate with others, which is not only harmonious and beautiful, but also in line with the provisions of the general drawing. If there are multiple exhaust points on the exhaust pipe, the branch pipe can be connected to a large section of manifold. The layout of ventilation ducts shall be as flat as possible to avoid the complexity of local pipeline installation. If the gas transmission pipeline contains droplets, a ramp shall be set on the ventilation pipeline, and a sealed water pipe shall be set at the lower end of the ventilation pipeline to facilitate the removal of exudates. Regulating and measuring devices shall be installed on the ventilation duct to facilitate the operation control of the system.
5. Insulation of ventilation duct
In the process of conveying air through the ventilation duct, the loss of heat and cooling capacity is large, and the air temperature should be kept basically constant. Therefore, it is necessary to maintain the insulation of the ventilation duct.
The above is the detailed introduction of Jinan ventilation duct. I hope it will be helpful to you If you have any questions, please contact us We will provide you with professional service http://www.jntfgd.com