Selection of FFU Fan Filter Unit and Matters Needing Attention

Fan filter Unit (Fan Filter Units), referred to as FFU. The utility model is a terminal air supply device with its own power and filtering function; the fan sucks the air from the top and is filtered by HEPA, and after filtration, the clean air is uniformly sent out from the air outlet surface; clean air and particulate filtration control are provided for the clean environment, and the fan filter unit can be modular connected. To meet the needs of different enterprises and scientific research institutions for different clean environments.

1. matters needing attention in the use of FFU. 

The fan filter unit is referred to as “FFU”, which is a high efficiency filter outlet with its own supply fan (non-shell fan). It forms a FFU system with its special keel system, pressurized fan, cooling coil, fresh air system and special lamps and lanterns. That is, the fan and filter (high efficiency filter or ultra-high efficiency filter) are combined to form an end purification equipment that can provide its own power. In the past, the air supply outlet, self-purifier and laminar flow cover of high-efficiency filter with fan, which are commonly used in cleaning engineering, are all a kind of FFU. You should pay attention to the following problems when selecting and installing FFU. 

1.1 noise control. 

FFU fans are generally several or even dozens of parallel use, when the design should consider the superposition of FFU noise, to ensure that “clean room design code GB50073-2001” clearly stipulated that “clean room noise level (empty), non-one-way flow clean room should not be greater than 60dB, one-way flow, mixed flow clean room should not be greater than 65dB” requirements. Therefore, when choosing the fan, it is best to choose the high-performance, press-out type, direct-drive radial blade fan, which can reduce the overall noise. 

1.2 selection of fan shell. 

When choosing the shell structure of FFU fan, we should not only consider to avoid fan leakage and eliminate the damage caused during transportation and handling, but also consider the disinfection with disinfectant and the environment in which FFU can be used, so it is best to choose stainless steel or aluminum alloy as the shell. 

1.3 selection of dragon skeleton. 

As the fan filter unit of FFU is installed directly between the ceiling frame, in order to make the filter easy and quick to replace, but also to keep the operation of the fan of FFU in balance, so as to reduce the probability of installation imbalance. Therefore, the professional matching dragon skeleton is generally considered. This kind of dragon frame is a section steel which is mechanically cold rolled into a special geometric shape (U shape). According to its environment, the metal surface is treated with anti-corrosion treatment (such as electrostatic spraying, hot-cold galvanizing, epoxy, etc.), which can not only ensure the strength of similar channel steel, but also meet the needs of FFU operation. 

1.4 selection of control mode. 

At present, FFU generally uses single-phase multi-speed AC motor, three-phase multi-speed AC motor and DC motor. The supply voltages of the motor are 110V, 220V, 270V and 380V. Its control mode is mainly divided into the following types: 

(1) Multi-speed switch control system: this system includes only one speed regulation switch and one power switch provided by FFU. Because the control element is FFU, which is distributed in every position in the ceiling of the clean room, the staff must adjust the FFU through the shift switch on the spot, which is very inconvenient to control, and the adjustable range of wind speed of FFU is limited to a few gears. The multi-stage switch control mode has the advantages of simple control and low cost, but it has many defects, such as high energy consumption, no smooth speed regulation, no feedback signal, flexible group control and so on. 

(2) continuous speed regulation control: compared with the multi-speed switch control mode, this system has one more continuous speed regulator, which makes the speed of the FFU fan continuously adjustable, but at the same time, it also sacrifices the motor efficiency and makes its energy consumption higher than that of the multi-speed switch control mode. 

(3) computer control: compared with the former two methods, the advanced function of computer control mode: not only can adopt the distributed control mode, it can easily realize the centralized monitoring and control of FFU, but also can conveniently realize the single, multi-set and partition control of FFU. In addition, the control system can set up a reserved communication interface, which can communicate with the host computer or network, so as to realize the function of remote communication and management. 

(4) remote control: as a supplement to the computer control mode, the remote control mode of this system can be used to control each FFU, which is complementary with the computer control mode. These control methods should be selected according to the actual situation. 

2. What are the characteristics of FFU. 

2.1 High efficiency and low noise turbofan. 

Computer three-dimensional modeling, simulation analysis, higher efficiency, lower noise. 

2.2 Beautiful appearance and humanized design. 

Equipped with stainless steel handle, easy to install and carry, corner fillet design, no indentation bending. 

2.3 Considerate and convenient design. 

The pedal is designed on the body to install the body and make it more convenient for maintenance. Equipped with stainless steel. 

2.4 High performance and low noise fan. 

The use of multi-wing turbine energy-saving fan, ultra-low noise, uniform wind pressure diffusion, uniform and stable network speed, low power consumption, low operating cost, working life of more than 80,000 hours. 

2.5 Multiple security protection. 

Touch control board, no mechanical key switch, single button induction, safe and reliable, overcurrent, overvoltage, overheat protection. 

2.6 Lightweight and thin body. 

Without filter screen, the thickness of the body is male 23cm, the weight is only 25KG, and the place with lower ceiling can also be applied. 

2.7 Optimized internal current sharing design. 

Ensure that the network speed uniformity deviation of FFU is less than ±10%. 

2.8 Flexible and diversified design. 

In addition to the standard models, we can make non-standard products of different specifications according to the needs of customers. Such as: the type of filter, stupid material and other changes. 

2.9 Versatile options