I. Design and calculation steps of ventilation duct system

1、繪制通風系統軸側圖，對個管段進行編號，標注各管段的長度和風量。以風量和風速不變的風管為一管段。一般從距風機遠的一段開始。由遠而近順序編號。管段長度按兩個管件中心線的長度計算，不扣除管件(如彎頭、三通)本身的長度。

1. Draw the axle-side diagram of the ventilation system, number each section, and mark the length and air volume of each section. A duct with constant wind volume and speed is used as a section. Generally from the farthest section from the fan. Numbered in order of distance and proximity. The length of the pipe section is calculated by the length of the center line of the two fittings, without deducting the length of the fittings (such as elbows and tees).

2、選擇合理的空氣流速。風管內的風速對系統的經濟性有較大影響。流速高、風管斷面小，材料消耗少，建造費用小;但是，系統壓力損失增大，動力消耗增加，有時還可能加速管道的磨損。流速低，壓力損失小，動力消耗少;但是風管斷面大，材料和建造費用增加。對除塵系統，流速多低會造成粉塵沉積，堵塞管道。因此必須進行的技術經濟比較，確定適當的經濟流速。根據經驗，對于一般的通風系統，其風速可按表6-10確定。對于除塵系統，防止粉塵在管道內的沉積所需的低風速可按表6-11確定。對于除塵器后的風管，風速可適當減小。

2. Choose reasonable air velocity. The wind speed in the duct has a great influence on the economy of the system. High flow rate, small cross section of air duct, less material consumption and less construction cost; however, the pressure loss of the system increases, power consumption increases, and sometimes the wear of the pipeline may be accelerated. Low velocity, low pressure loss and low power consumption, but large cross-section of air duct, increased material and construction costs. For the dust removal system, how low the flow rate will cause dust deposition and plug the pipeline. Therefore, a comprehensive technical and economic comparison must be made to determine the appropriate economic flow rate. According to experience, for general ventilation systems, the wind speed can be determined according to Table 6-10. For dust removal systems, the minimum wind speed required to prevent dust deposition in the pipeline can be determined according to Table 6-11. For the duct after the dust collector, the wind speed can be reduced appropriately.

3、根據各管段的風量和選定的流速確定各段管徑(或斷面尺寸)，計算各管段的摩擦和局部壓力損失。

3. Determine the diameter (or cross-section size) of each section according to the air volume and selected flow velocity of each section, and calculate the friction and local pressure loss of each section.

確定管徑時，應盡可能采用表6-2表6-3中所列的通風管道統一規格，以利于工業化加工制作。

When determining pipe diameter, the uniform specification of ventilation pipes listed in Table 6-2 and Table 6-3 should be adopted as far as possible to facilitate industrial processing and production.

壓力損失計算應從不利的環路(即距風機遠的排風點)開始。

The calculation of pressure loss should start with the most disadvantageous loop (i.e. the farthest exhaust point from the fan).

對于袋式除塵器和電除塵器后的風管，應把除塵器的漏風及反吹風量計入。除塵器的漏風濾見有關的產品說明書，袋式除塵器的漏風率一般為5%左右。

For the air duct after bag filter and ESP, the air leakage and back-blowing of the dust collector should be counted. Leakage rate of bag filter is generally about 5%.

通風管道

Ventilating duct

4、對并聯管路進行壓力平衡計算。一般的通風系統要求兩支管的壓損差不超過15%，除塵系統要求兩支管的壓損差不超過10%，以保證各支管的風量達到設計要求。

4. Calculate the pressure balance of parallel pipeline. The general ventilation system requires that the pressure loss difference between the two pipes should not exceed 15%, and the dust removal system requires that the pressure loss difference between the two pipes should not exceed 10%, so as to ensure that the air volume of each branch pipe meets the design requirements.

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From the introduction of the above ventilation duct manufacturer, we can see that our ventilation duct is very popular now. Now the ventilation duct has become a product everywhere around us. If you don't know about the ventilation duct or want to consult and buy it, you can call us or leave a message in the background. We will reply to you in time.