Principles of Combination of Fans and Ducts in Commercial Kitchens

In the design of smoke exhaust ventilation system, the fan and pipeline need to be designed. According to the environmental conditions, there are many combined working modes between the fan and the pipeline. Different combination methods have different system performance, and different methods are needed to analyze and calculate the air volume and pressure loss in the pipeline, so as to carry out scientific and reasonable matching design.

The combination of fan and pipe.

(1) Centralized smoke exhaust

Several smoke hoods in the kitchen share a fan, one main flue for smoke exhaust, and the system is centrally controlled, which is called centralized smoke exhaust. This kind of working mode can not control smoke flexibly according to the working time of the equipment, and the working time of the fan is long, which is easy to cause waste. Once the failure occurs, the kitchen smoke exhaust facilities are all paralyzed and can not work normally in a short time. In the design, the balance of pressure and air volume of each branch pipe should be considered, and the design calculation is relatively complex.

(2) Decentralized smoke exhaust

One smoke hood, one fan and one pipe are used for smoke exhaust. According to the working time switch of equipment, each hood can be controlled separately, and the control is convenient. The fan and pipeline are easier to optimize design, and work in high efficiency state, and each subsystem is efficient and energy-saving. According to the exhaust air volume, the fan of common type is selected. The longer smoke hood can also be divided into several sections, or the smoke exhaust hood with the same working time can be combined to smoke at the same time, and the switch machine is required. Once the fan fails, it can be repaired or replaced immediately, without affecting the whole kitchen work. The fresh air can also be connected randomly, ensuring pressure balance, convenient control, energy saving and consumption reduction.

(3) Fan parallel operation mode

Only one main flue is available, and many fans are discharged into this main flue, which is the parallel operation mode of the fan. The kitchen of different floors is equipped with smoke exhaust fan, and only one main flue can be used for smoke exhaust. The system is a decentralized control method of sharing one main flue. In order to prevent the smoke from being injected back, each layer is equipped with electric check valve, which works in synchronization with the fan. Each set of switches and meters, self-control, when necessary, start smoke, do not need to shut down, meters respectively measured electricity consumption, not contradictory, conducive to energy saving and calculation costs.

(4) Fan series

When the exhaust pressure of one fan cannot meet the needs, it is necessary to use two fans to exhaust air on a pipe in series, which is the fan series operation mode.