Laboratory Classification and Design Requirements
1. Laboratory Classification and Responsibilities
The laboratory, also known as the analytical testing facility, varies across schools, factories, and research institutions.
In schools, one type of laboratory serves as a teaching base for students performing analytical chemistry experiments, while another type supports research, with a focus on analytical chemistry.
Factories have central laboratories and workshop laboratories. The workshop laboratories mainly handle control analyses of products, semi-finished products, and materials in the production process. The central laboratory is responsible for analysis, product testing, and research on testing methods, along with preparation and calibration of solutions for the workshop laboratories.
In research institutions, laboratories perform testing tasks for scientific research topics while also conducting research in analytical chemistry.
2. Laboratory Design Requirements
Based on the analytical tasks, laboratories often contain expensive precision instruments and various chemicals, including flammable and corrosive substances. Additionally, harmful gases or vapors are often generated during operations. Therefore, there are specific requirements for the structure of the laboratory, its environment, and its facilities. These requirements should be considered when constructing a new laboratory or renovating an existing one.
Laboratories are generally divided into three categories: precision instrument laboratories, chemical analysis laboratories, and auxiliary rooms (offices, storage rooms, gas cylinder rooms, etc.). Laboratories should be located away from sources of dust, smoke, noise, and vibration. Therefore, laboratories should not be built near transportation routes, boiler rooms, electrical rooms, or production workshops (except for workshop laboratories). To maintain good environmental conditions, laboratories are generally oriented in a north-south direction.
1. Precision Instrument Rooms
Precision instrument rooms require fireproof, shockproof, electromagnetic interference-resistant, noise-reducing, moisture-proof, corrosion-resistant, dustproof, and harmful gas-proof features. The room temperature should be kept as constant as possible. To maintain good performance of most instruments, the temperature should be between 15°C and 30°C, ideally between 18°C and 25°C. The humidity should be between 60% and 70%. If necessary, the room can be equipped with double-layer windows and air conditioning systems.
Precision instrument rooms can have terrazzo flooring or anti-static floors, while carpets are not recommended due to their tendency to accumulate dust and generate static electricity. Large precision instrument rooms should have a stable power supply, with voltage fluctuations typically within ±10%. In case of instability, additional equipment like voltage stabilizers may be needed. To ensure an uninterrupted power supply, dual power supply systems can be used, with dedicated grounding designed for safety, ensuring the ground resistance is less than 4Ω.
Gas Chromatography and Atomic Absorption Rooms
These rooms often use high-pressure gas cylinders, so it’s best to place them near an external gas cylinder room (facing north). The experiment tables should be placed 500mm away from the walls for easy operation and maintenance. The room should have good ventilation, and fume hoods should be installed above atomic absorption instruments to handle exhaust gases.
For instruments that rely on microcomputers or microcomputer control, stable power voltage and frequency are required. Uninterruptible power supplies (UPS) can be used to prevent issues such as voltage surges, brief power outages, or insufficient voltage.
When designing specialized instrument analysis rooms, it is important to also design adjacent chemical processing rooms to protect the instruments and enhance safety.
2. Fume Hoods
Fume hoods are commonly used local exhaust devices in laboratories. They are equipped with heat sources, water sources, and lighting. They can be made from fireproof and explosion-proof materials, with anti-corrosion coatings. The ventilation pipes should be resistant to acid and alkali gas corrosion. The exhaust fan can be installed in the rooftop machine room and should be equipped with vibration and noise reduction devices. The exhaust pipe should be at least 2 meters above the roof.
The fume hood should be placed in an area with minimal air disturbance, or a slotted fume hood can be used. The counter of the fume hood should be 800mm high, 750mm wide, and the interior height should be between 1200mm and 1500mm. The operation opening should be 800mm, and the hood length should be between 1200mm and 1800mm. The air velocity through the slot should be between 0.3 to 0.5 m/s, and the window height should be 300-500mm. The width of the exhaust duct behind the baffle should be at least twice the size of the slot width.
3. Auxiliary Rooms
Chemical Storage Rooms
Many chemicals are flammable, explosive, toxic, or corrosive, so storage of chemicals should be limited to small amounts that are needed for immediate use. The storage room should meet safety requirements for hazardous materials, and it should be designed with fire prevention, moisture control, temperature control, sunlight protection, and lightning protection in mind.
Gas Cylinder Rooms
Flammable or oxidizing gas cylinders should be stored in outdoor gas cylinder rooms, located away from heat sources, open flames, or combustible materials. The room should be constructed from non-combustible or fire-resistant materials, with blast-proof walls and a lightweight roof. The door should open outward, and the room should be well-ventilated, avoiding direct sunlight exposure.