Physical and chemical laboratory process design
The food inspection and monitoring laboratory is professionally involved in many disciplines such as food physics, chemistry, microbiology, molecular biology and food sensory evaluation. In terms of function, it also involves complex technology such as water supply and drainage, ventilation, exhaust, strong current, weak current, air conditioning, fire fighting, waste gas, waste liquid treatment, and centralized gas supply. At the same time, it also takes into account environmental protection, safety, sustainable development and many other factors, so it is a complex system engineering.
1. Design requirements
Environmental requirement
1. Ventilation:
Because the laboratory often has a long experiment time, many personnel and some harmful gases will be produced during the experiment, resulting in air pollution and unfavorable to the human body. In order to prevent laboratory workers from inhaling or ingesting some toxic, pathogenic or toxic chemicals and organic gases, the laboratory should be well ventilated and must have air conditioning. Ventilation equipment includes: fume hood, hood or local ventilation device.
2. Temperature and humidity:
The right temperature and humidity are required in the laboratory. The indoor microclimate, including temperature, humidity and airflow speed, will have an impact on the personnel and equipment working in the laboratory. The appropriate temperature in summer should be 18 ~ 28 ° C, 16 ~ 20 ° C in winter, and the humidity is best between 30%(winter) and 70%(summer).
3. Cleanliness:
The laboratory must be kept clean at all times. Dust in the outdoor air, in the ventilation process will enter the laboratory, the amount of dust in the experiment is too high, the air is not clean, not only affect the test results, but also, its particles fall on the surface of the instrument and equipment, may constitute obstacles, and even cause short circuit or other potential hazards.
2. Facility requirements
1. Water supply and drainage, sewage:
The laboratory must have a water supply and drainage device, and the drainage device is best to use polyvinyl chloride pipe, and the interface is welded with a welding torch. The chemical test bench may be installed water pipes, faucets, sinks, emergency flushes, eye washers, etc., the general laboratory wastewater can be discharged into the urban water network without treatment, and the harmful laboratory wastewater must be purified and treated before it can be discharged into the water network.
2. Power supply:
Electricity is an important driving force in the laboratory. In order to ensure the normal operation of the laboratory, the quality, safety, reliability and continuity of the power supply must be guaranteed. General electricity and experimental electricity must be separated; For some precision and valuable instruments and equipment, it is required to provide a power supply with stable voltage, constant current, stable frequency and anti-interference; If necessary, it is necessary to establish an uninterrupted power supply system, but also equipped with a dedicated power supply, such as uninterruptible power supply (UPS).
3. Gas supply and exhaust:
The compressed gas cylinders used in the laboratory should be kept in a minimum number, must be firmly fixed, or tied with metal chains, and must not be used near the source of fire, direct sunlight, high temperature rooms and other places where the temperature may rise. Laboratory waste gas treatment, such as a small amount, can be directly discharged outside; However, the discharge pipe must be about 3m higher than the nearby roof, and the waste gas with large toxicity or a large number can be treated by referring to industrial waste gas treatment methods such as adsorption, absorption, oxidation, decomposition and other methods.
Third, function and layout
According to the characteristics of the laboratory work of the physical and chemical laboratory, a safe, comfortable and beautified laboratory working environment should be created, and the office area is separated from the experimental area, that is, the uncontrolled area and the controlled area are formed. The physical and chemical laboratory should be equipped with office, archive room (report preparation room), sample collection and sample storage room, large instrument room, small instrument room, balance room (glass gauge verification room), chemical experiment and sample pretreatment room, electric baking room, washing room, experimental water (ultra-pure water) preparation room, darkroom, reagent storage room.
Uncontrolled region
Office:
For the staff of the department to study and discuss the problems in the work after work. The archives room (report preparation room) is used for the preparation and printing of reports, storage and access to department materials.
Sample collection room:
Independent sample storage room, storage cabinet function interval should be clearly divided, marked untested samples, samples in the test and samples have been tested. The sample room must be dry, ventilated, dustproof and rat-proof.
Chemical experiment and sample pretreatment room:
The laboratory must have exhaust facilities, independent exhaust cabinets, and separate organic and inorganic pretreatment; Walls, floors, test tables, reagent cabinets, etc. should be insulated, heat resistant, acid and alkali resistant and organic solvent corrosion resistant; The ground should be leaky to prevent backflow. The laboratory where the central test bench is set up shall be provided with the water supply device and the power plug for the test bench.
Large instrument room:
The voltage, current, and temperature and humidity meet the requirements. An ESD floor is required. The temperature ranges from 15 to 25 ° C, and the humidity ranges from 60 to 70%. Instruments that interfere with each other should not be placed in the same room, and instruments that detect inorganic substances should have exhaust pipes; The instrument for detecting organic substances has an adjustable exhaust hood.
Balance room:
The balance room should have double glass and curtains, a constant temperature and humidity system, the balance table must be shockproof, the balance table must be placed 1cm away from the wall, can buy shockproof balance table or brick marble countertop balance table. Small instrument room
The small instrument room should have enough power sockets, it is best to install a voltage regulator, equipped with a pool.
IDD Laboratory:
In order to prevent cross-contamination, there are independent laboratories with independent digestion cabinets.
Electric grill room:
There should be enough electric power, and it is best to use fireproof materials as partitions.
Washing room:
There should be a special area for cleaning glassware, separate utensils for organic analysis from those for inorganic analysis, and special utensils for testing toxic substances.
Laboratory water preparation room:
To have dust-proof facilities, the workbench should be strong and heat-resistant, equipped with a power line that can meet the power requirements of the water making equipment. The water supply faucet should have a slag screen.
Darkroom:
For the detection of fluorescent substances, mycotoxins and light-repellent substances, both to avoid light and ventilation, it is best to install gas cabinets.