1、 Composition of kitchen smoke exhaust system

廚房排煙系統主要由集煙罩、排煙管、消防閥、油煙凈化器設備、排煙風機（含消聲器）、廚房綜合送風裝置等組成。油煙凈化器設備的類型和運行方式可根據實際情況選擇。安裝油煙凈化器前，應計算排煙系統各部分的實際運行參數，包括運行阻力和排氣量。如果要新建項目，應充分考慮在排氣系統上安裝油煙凈化器的影響。如果是改造項目，安裝油煙凈化器時需要重新計算排氣系統。必要時對廚房集煙罩、排煙管、整體送風裝置進行改造，更換排風機。

The kitchen smoke exhaust system is mainly composed of smoke collecting hood, smoke exhaust pipe, fire valve, lampblack purifier equipment, smoke exhaust fan (including muffler), kitchen integrated air supply device, etc. The type and operation mode of lampblack purifier can be selected according to the actual situation. Before installing the lampblack purifier, the actual operating parameters of each part of the smoke exhaust system shall be calculated first, including operating resistance and exhaust volume. If a new project is to be built, the impact of installing a fume purifier on the exhaust system shall be fully considered. If it is a reconstruction project, the exhaust system needs to be recalculated when installing the lampblack purifier. If necessary, the kitchen hood, smoke exhaust pipe and integral air supply device shall be modified, and the exhaust fan shall be replaced.

二、集煙罩

2、 Smoke collecting hood

集煙罩一般為整體加工，包括過濾、集油、集水等設備，主要由廚房公司制造。其外觀應均勻、美觀、易于清潔。廚房通風時，需要添加一定量的新鮮空氣。一方面可以平衡空氣壓力，避免廚房負壓過大（一般小于5pa），另一方面可以降低廚房溫度，改善工作環境。烹飪煙氣收集罩主要有三種類型：

The smoke collection hood is generally processed as a whole, including filtering, oil collection, water collection and other equipment, and is mainly manufactured by professional kitchen companies. The appearance shall be uniform, beautiful and easy to clean. When the kitchen is ventilated, a certain amount of fresh air needs to be added. On the one hand, it can balance the air pressure to avoid excessive negative pressure in the kitchen (generally less than 5pa), on the other hand, it can reduce the kitchen temperature and improve the working environment. There are three main types of cooking fume collection hoods:

（1） 簡易集氣罩為無油供氣設備，適用于各種靈活場所，加工安裝方便，低廉。但由于缺乏送風設備，集風效果差，容易使煙氣在廚房工作人員面前旋轉，容易造成油滴分散。

(1) The simple gas collecting hood is an oil-free gas supply equipment, which is suitable for various flexible places. It is easy to process and install, and the price is low. However, due to the lack of air supply equipment, the air collection effect is poor, which is easy to make the smoke rotate in front of the kitchen staff and cause oil droplets to disperse.

（2） 帶油罩和供氣裝置的空氣濃縮器能更好地收集烹飪過程中產生的煙霧，油滴不會脫落。只要送風合理，廚房操作人員工作面空氣質量良好。但安裝要求高，投資大。

(2) The air concentrator with oil hood and air supply device can better collect the smoke generated during cooking, and the oil drops will not fall off. As long as the air supply is reasonable, the air quality of the kitchen operator's working face is good. However, the installation requirements are high and the investment is large.

（3） 水和氣體收集（煙霧）蓋

(3) Water and gas collection (smoke) cover

輸水集氣罩的設計原則是與油煙碰撞后形成水幕循環，凈化油煙。影響輸水集氣罩使用效果的關鍵是形成連續的水幕，循環水系統需要定期清洗。事實上，由于管理不善，大多數水和氣體（煙霧）帽不會形成連續的水幕，而只能形成間歇性水滴或小水柱，這使得它們無法使用。

The design principle of the water conveyance and gas collecting hood is to form a water curtain circulation after collision with the lampblack to purify the lampblack. The key to affect the use effect of the water conveyance and gas collecting hood is to form a continuous water curtain, and the circulating water system needs to be cleaned regularly. In fact, due to poor management, most water and gas (smoke) caps will not form a continuous water curtain, but can only form intermittent water droplets or small water columns, which makes them unusable.

三、排煙管道

3、 Smoke exhaust pipe

廚房排氣管的水平段不宜過長。一般情況下，水平距離不應超過15米，坡度應大于2%。水平端有可移動的接頭，便于機油。根據規范，排氣速度不得小于10m/s，以防止油因低風速而粘附在煙道上。連接到排氣罩的支架應配備空氣流量控制閥。

The horizontal section of kitchen exhaust pipe should not be too long. Generally, the maximum horizontal distance shall not exceed 15m and the gradient shall be greater than 2%. The horizontal end has a movable joint for easy removal of oil. According to the specification, the exhaust velocity shall not be less than 10m/s to prevent oil from adhering to the flue due to low wind speed. Supports attached to exhaust hoods shall be equipped with air flow control valves.

排煙管的不合理設計和安裝往往會導致廚房產生煙氣，直接影響煙氣凈化器的使用。主要原因如下：

The unreasonable design and installation of smoke exhaust pipe will often lead to smoke in the kitchen, which directly affects the use of smoke purifier. The main reasons are as follows:

（1） 主排氣管道通風面積不足，氣流較大。根據工程經驗，主排氣管內的風速不超過15m/s。否則，運行一段時間（如一年）后，很容易造成排煙系統堵塞。在油煙凈化器的運行實踐中，大多數情況下，排煙管因通風面積不足而堵塞，管內氣體流速大于15m/s。

(1) The ventilation area of the main exhaust pipe is insufficient and the air flow is large. According to engineering experience, the wind speed in the main exhaust pipe shall not exceed 15m/s. Otherwise, after a period of operation (such as one year), it is easy to cause the smoke exhaust system to be blocked. In the operation practice of the oil fume purifier, in most cases, the smoke exhaust pipe is blocked due to insufficient ventilation area, and the gas velocity in the pipe is greater than 15m/s.

（2） 當排煙管穿過建筑梁時，通風的橫截面積變小，橫截面積上的阻力增大，從而使氣流順暢。

(2) When the smoke exhaust pipe passes through the building beam, the cross sectional area of ventilation becomes smaller, and the resistance on the cross sectional area increases, thus making the air flow smooth.

（3） 當排氣管穿過建筑梁或避開其他設備管道時，一段排氣管將低于整個排氣管的平面。使用一段時間后，油水混合物會積聚在排氣管的下部，直接影響排氣煙的平滑度。

(3) When the exhaust pipe passes through the building beam or avoids other equipment pipes, a section of exhaust pipe will be lower than the plane of the entire exhaust pipe. After using for a period of time, the oil-water mixture will accumulate in the lower part of the exhaust pipe, which directly affects the smoothness of the exhaust smoke.

（4） 來自不同樓層的廚房煙氣通過同一主管排放。在靠近出口的地板上，廚房的煙比較好，但在較低的廚房里，煙并不順暢。

(4) The kitchen smoke from different floors is discharged through the same main pipe. On the floor near the exit, the smoke in the kitchen is better, but in the lower kitchen, the smoke is not smooth.

四、風機

4、 Fan

1.常用的排風機有三種：軸流風機、風柜風機和離心風機。

1. There are three types of exhaust fans in common use: axial flow fan, fan cabinet fan and centrifugal fan.

（1） 軸流風機以前應用廣泛，但由于總壓較低，安裝油煙凈化器后很少使用。然而，它通常用于低空油煙凈化器的設計和安裝。

(1) Axial flow fan was widely used before, but it was rarely used after installing lampblack purifier due to low total pressure. However, it is usually used for the design and installation of low altitude lampblack purifier.

（2） 風柜風機總壓中等，風量可調，噪音低。它通常用于從發動機罩到排煙口中等距離的廚房排煙系統。

(2) The total pressure of the fan of the air cabinet is medium, the air volume is adjustable, and the noise is low. It is usually used for kitchen smoke exhaust system with medium distance from engine hood to smoke exhaust outlet.

（3） 離心風機的總壓力和體積可以調節，但由于噪音高，通常需要降低噪音。當廚房位于建筑物底部時，其排氣扇應放置在屋頂上。一方面可以減少室內噪聲污染，同時排氣管處于負壓狀態，避免臭氣外溢。當風機放置在屋頂上時，通常選擇離心式風機。

(3) The total pressure and volume of the centrifugal fan can be adjusted, but because of the high noise, it is usually necessary to reduce the noise. When the kitchen is located at the bottom of the building, its exhaust fan should be placed on the roof. On the one hand, it can reduce indoor noise pollution, and at the same time, the exhaust pipe is in a negative pressure state to avoid odor overflow. When the fan is placed on the roof, centrifugal fan is usually selected.

2.廚房排煙量的測定

2. Measurement of kitchen smoke exhaust

為保證凈化效果，在實際設計中，要求嚴格按照排氣罩的吸入速度計算排氣量。發動機罩的吸氣速度一般不小于0.5m/s。

In order to ensure the purification effect, in the actual design, it is required to calculate the exhaust volume in strict accordance with the suction speed of the exhaust hood. The suction speed of the engine hood is generally not less than 0.5m/s.

五、油煙凈化器

5、 Oil fume purifier

1.處理空氣流量的測量：

1. Measurement of treatment air flow:

靜電油煙凈化器處理風量的確定一般有三個主要依據：一是根據排風罩投影面積計算排風量；另一個是爐子的數量；一個是從匹配的吸入柜中抽出的空氣量。

Generally, there are three main bases for determining the air volume to be handled by the electrostatic lampblack purifier: first, calculate the air volume according to the projected area of the exhaust hood; The other is the number of furnaces; One is the amount of air pumped from the matched suction cabinet.

1）根據集油煙罩總投影面積（S）選型：處理風量=S（m2）×2500≤油煙凈化器量。

1) Model selection according to the total projected area (S) of the oil collecting hood: treated air volume=S (m2) × 2500 ≤ oil smoke purifier volume.

2） 根據爐子的選擇：

2) According to the choice of furnace:

每個標準爐（φ=350mm），風量2000m3/h，總處理風量=爐數×2000m3/h，然后根據總風量確定設備型號。

Each standard furnace（ φ= 350mm), air volume 2000m3/h, total treated air volume=number of boilers × 2000m3/h, and then determine the equipment model according to the total air volume.

3） 根據原風機匹配選擇：所選凈化器型號與原風機風量匹配。

3) Selection according to the matching of the original fan: the selected purifier model matches the air volume of the original fan.

4） 根據匹配的風扇進行選擇

4) Select according to the matching fan

（1） 計算系統管網壓力損失：系統管網壓力損失包括局部壓力損失和沿途壓力損失。局部壓力損失：每個減壓器、彎頭、入口和出口的壓力損失

(1) Calculation of system pipe network pressure loss: system pipe network pressure loss includes local pressure loss and pressure loss along the way. Local pressure loss: pressure loss of each reducer, elbow, inlet and outlet

沿途壓力損失：直線段壓力損失

Pressure loss along the way: pressure loss in straight section

（2） 風機總壓力=（管網壓力損失+設備壓力損失）×（100+20）%

(2) Total fan pressure=(pipe network pressure loss+equipment pressure loss) × （100+20）%

根據風機的總壓力選擇風機的類型和規格

Select the type and specification of the fan according to the total pressure of the fan

風機額定容量=復合煙氣凈化器總處理量×1.2%

Rated capacity of fan=total treatment capacity of composite flue gas purifier × 1.2%

5）蔬菜產生的揮發性油煙較大，凈化器的設計容量應增加40%

5) The volatile oil fume produced by vegetables is large, and the design capacity of the purifier should be increased by 40%