Generally, the height of the old factory building is about 3m, and the area and shape are different from the actual needs. Usually, it is not possible to install air ducts, technical sandwiches and special air conditioning systems in accordance with the conventional installation. According to the basic principles of air purification, in practice, we have explored a very practical dust-free workshop technology transformation method, especially suitable for small and medium-sized dust-free workshop technology transformation. The following are introduced:
1. Structural model
The dust-free workshop is built in the old workshop with a room height of 3 m. The wall of the dust-free workshop is constructed with sandwich color steel plate. The height of the dust-free workshop is 2.4 M. The top of the dust-free workshop is a fan room with a height of 0.6 m, which is equipped with a fan box. All sides of the fan room are closed, and there is an intermediate filtering air inlet for inward ventilation. The fan is installed in the fan box. The lower part of the fan box is the static pressure box and the high efficiency filter. There is no return air primary filter on the lower side of the dust-free workshop. The outside of the dust-free workshop is the return air duct. The return air duct is connected with each other. At least one split air conditioner is in it. The air conditioner can first use the ordinary cabinet split air conditioner. The outlet of the air conditioner is equipped with a guide hood and a cold air duct, and the other end of the cold air duct is installed in the fan room. In general, the air supply fan of general air conditioning can send the cold air beyond 15 m, which can basically meet the needs of general small and medium-sized dust-free workshop. When the air supply distance is relatively long, the air supply pipe can be equipped with a fan to increase the air supply pressure.
It must be noted that the guide hood and the cold air duct must be insulated. In general, the thickness of the indoor unit of the common cabinet split air conditioner is 0.25 m~0.35 M. Considering the width of the guide hood, the width of the return air duct can be made into 0.5 m~0.7 M. When wall-mounted air conditioning is selected, the width of the return air duct can also be reduced, and the width of the remaining return air ducts can be made into 0.1 M. In this way, the design of dust-free workshop can maximize the use of building space.
2. Air circulation mode
The air flow is fed into the static pressure box by air, enters the dust-free workshop through the high efficiency filter, and then enters the return air chute from the return air primary effect filter. Part of the return air flow and fresh air coming from the fresh air primary effect filter enter the fan room through the intermediate effect filter. The other part of the return air flow directly enters the air-conditioning inlet. After air cooling, it enters the fan room through the guide hood and the cold air duct. After mixing the two parts of the flow in the fan room, the fan is fed into the static pressure box through the medium-effect filter on the fan box, and then the high-efficiency filter is fed into the dust-free workshop to form the air circulation system. From the circulation of air flow, we can see that in fact, a good three-stage filtration state has been formed. Therefore, the air quality of dust-free workshop has been guaranteed reliably. On this basis, by adjusting the structure and layout of the air supply port of the high efficiency filter and matching the corresponding air volume, the clean form and cleanliness of the dust-free workshop can be determined to meet different needs.
DOP Leakage Detection Test of Ultra-clean Workbench High Efficiency Filter
Why DOP Leak Detection Test for High Efficiency Filter of Ultra-clean Workbench?
If there are defects in the installation of high-efficiency filters, such as small holes in the filters themselves or small cracks caused by improper installation, it will lead to less than the intended purification effect. Therefore, after installing or replacing the high efficiency filter, it is necessary to check the leakage of the filter and the installation connection.
2. Leak detection purpose
By testing the leakage of the high efficiency filter, the defects of the high efficiency filter and its installation are found, so as to take remedial measures.
3. Leak detection range
Clean area, laminar flow table and high efficiency filters on equipment, etc.
4. Leak detection methods
The commonly used method is DOP leak detection (that is, using DOP solvent as dust source, cooperating with aerosol photometer), or dust particle counter scanning method (that is, using atmospheric dust as dust source, cooperating with particle counter leak detection). Because the reading of particle counter is cumulative, which is not conducive to scanning, and the speed of inspection is slow. In addition, on the windward side of the tested high-efficiency filter, the concentration of atmospheric dust is often low, and it is easy to find leaks only by supplementing smoke. These deficiencies of particle counter method can be compensated by DOP method, so DOP method is widely used abroad for leak detection.
5. DOP leak detection
5.1. Working Principle
The DOP aerosol on the upper side of the detected high-efficiency filter was used as a dust source (DOP, namely two octyl phthalate two, 390.57 of the molecular weight, and the shape of the particles after spraying). The samples were collected on the downwind side with a photometer. The collected air samples were transferred through the photometer diffusion chamber, and the scattered light generated by the photometer was converted to electricity by photoelectric effect and linear amplification. The relative concentration of aerosols can be measured by rapid display of the table. DOP test actually measured the penetration rate of the high efficiency filter.
5.2. Materials and Instruments
(1) Dust source (DOP solvent);
(2) DOP generator [In order to produce smoke device, DOP solvent is poured into the generator container, aerosol smoke generated under certain pressure or heating conditions is fed to the upper wind side of the high efficiency filter (heating DOP liquid to form DOP vapor, condensation of steam into small droplets under specific conditions, removal of excessive and small droplets, leaving only about 0.3 um particles, foggy DOP into the air duct). );
(3) Aerosol photometer (the instrument for measuring and displaying aerosol concentration should indicate the validity period of the calibration, which must be qualified and used within the validity period);
Epoxy resin silica gel;
_High-efficiency filters of spare required models
5.3. Leak detection test procedure
5.3.1. Leak detection preparation
Prepare the layout plan of air supply duct of purified air conditioning system for leak detection and the area to be inspected, and notify purified air conditioning equipment company to inspect
Suzhou headquarters：No. 99 Tongcheng Road, Weitang Town, Xiangcheng District, Suzhou
Contacts：Hu Ji Yong