Use the following ten cost factor variables to provide an alternative design for the basic clean room Design and standards are improved to meet the needs of the plant, and we should be able to reduce project engineering costs through these methods. Suitable for clean room planning and construction in the biopharmaceutical, microelectronics and food processing industries.
01 Number of air changes
The ratio of pollutants in the room and the actual particle generation are the main factors affecting the air exchange frequency in the clean room. In the production process, the speed of particle removal is very important without any influence on other factors. Other factors that may affect the amount of recirculated air are: the structure of the room, the location of the equipment, the surface temperature of the equipment, air convection, type of airflow, operating space and regulations, materials used, and chemicals.
02 Unidirectional, turbulent, vertical or horizontal airflow
In many cases, unidirectional airflow is used only in sensitive areas of small spaces and clean rooms, and Microenvironment. The source of the contaminants may be present in the glove box, filter module, etc. Most are designed as a one-way airflow clean room, and only one operator, production equipment and exhaust unit can achieve unidirectional airflow in these areas. The choice of vertical or horizontal airflow depends on the structure of the room and the location of the equipment, and turbulence can carry the contaminants away.
03 Air Filtration
Other equipment may be selected depending on the purpose of the clean room, for example, in a circulating air plus fresh air treatment system, using a HEPA filter for carbon adsorption or similar functions. The synthetic filter handles VOC, electrostatic filter boxes, and more. In the clean room market, fan filtration is no longer a new product. Proper application can provide excellent, economical solutions for many high-level cleanrooms, especially in buildings with limited ceiling heights.
The fresh air treatment air conditioner provides the necessary fresh air for the clean room. The multi-circulating air-conditioning box passes through the air supply duct and then passes through the ULPA filter or HEPA filter to send the air into the clean room. On the ceiling of the clean room with cleanliness class 10 and class 1, these filters are usually 100. %cover. The vertical unidirectional airflow passes down through the clean room, passes through the perforated floor tile with holes to enter the return air space below the floor, and then enters the ceiling return air static pressure box through the vertical return air channel. Then, the air enters the circulating air conditioner again, and the above air circulation repeats again.
05 Air pressure difference
Clean room pressurization is necessary to ensure that the clean room is away from the pollution of its adjacent area, control the flow of harmful pollutants, and prevent different areas. Cross-contamination and help maintain the required temperature and humidity levels. The pressure differential between the clean room and associated corridors, and other areas within the facility should be maintained between 0.25 and 0.005 inches of water (in.w.g.). General pharmaceutical companies require higher pressure differentials than this, using a laminated pressure differential between different zones to avoid cross-contamination. A series of stacked air locks and positive pressure gates that allow rapid air diffusion are installed between the different areas to create a pressure differential.
06 Temperature Control
Changes in temperature and humidity can cause errors in production equipment, which can affect the repeatability of the production process, ultimately leading to lower product yields and increased waste. Therefore, the strict control of temperature in the clean room is obvious, and this cost is necessary. Under normal circumstances, engineers are required to reduce construction costs during design, and require precise temperature control in a large area. If there are strict requirements for heating, power professional equipment and control systems in the clean room, in each clean room Within the area, there is a local thermostat to control the design temperature. It can drive local reheat or re-cold coils installed on the duct to meet the damp heat requirements of the room.
07 Humidity Control
The relative humidity in each clean room is controlled by a local humidity regulator. When accurate humidity control must be met, it is usually achieved by the adiabatic humidification effect of the fresh air in the air conditioning box. The local variation of the humidity level can be controlled by the ultrasonic humidity regulator, which is located in the static pressure of the duct before the final filtration. Inside the box.
08 Exhaust System
Quality air handling equipment minimizes exhaust emissions and therefore reduces engineering costs and energy waste during implementation. It is important to maintain a balance between the potential demand for increased exhaust air volume and the economic value required to expand production and install these supplies.
09 Static charge on the surface of air and objects
“Static” is caused by the contact of two separate surfaces. The charges generated by different surfaces, if not transmitted to the ground at a fast enough rate, will accumulate and spread over the surface of the material – this is “static”. Residual static charge in many areas of the industry poses a hazard and causes problems. It can cause the burning of flammable gases and electric shock. It can bond thin films and light fibers, absorb dust and debris from the air, damage semiconductor devices and interfere with the operation of microelectronic devices. The most basic way to avoid the effects of electrostatic discharge on microelectronic systems is to place the device in a good place for electrostatic and magnetic shielding, properly reducing all input and output connections.
10 Forms and Functions
The strict cleaning requirements of cleanrooms are related to its inherently high production costs. However, if you plan ahead, you can greatly reduce your costs:
Precisionally define clean room levels to meet process requirements.
Precisely define clean room air temperature and humidity to meet process requirements.
The amount of exhaust air outside the clean room should meet the minimum requirements of the process, and the exhaust management procedure should be performed from the beginning.
Reducing the pressure drop across the duct and piping by determining the maximum and minimum wind speeds of the equipment and implementing these guidelines throughout the construction process.