Summarize the basic knowledge of laminar flow cabinet

Core Tip: The ultra clean workbench is a one-way flow air purification device that provides a local dust-free and sterile working environment. Widely used in medical and health, biopharmaceutical, food, medical science experiments
The ultra clean workbench is a one-way flow type air purification equipment that provides a local dust-free and sterile working environment. It is widely used in scientific research and production departments that require a locally clean and sterile working environment such as medicine and health, biopharmaceutical, food, medical science experiments, optics, electronics, sterile room experiments, sterile microbial testing, plant tissue culture and inoculation. It can also be connected to an assembly line with advantages such as low noise and mobility. It is an air purification equipment that provides a highly versatile working environment with local high cleanliness. Its use has good effects on improving process conditions, improving product quality, and increasing the yield.
Note: A clean bench is different from a biosafety cabinet.
The ultra clean workbench can only protect the reagents operated inside the workbench from contamination, and does not protect workers. The biosafety cabinet is a negative pressure system that can effectively protect workers.
Its working principle is
The air is sucked into the pre filter through a fan, and then enters the high efficiency filter through a static pressure box for filtration. The filtered air is sent out in a vertical or horizontal airflow state, enabling the operating area to achieve a level 100 cleanliness level and ensuring the environmental cleanliness requirements of production. According to the direction of air flow, the ultra-clean workbench is divided into vertical flow ultra-clean workbench and horizontal flow ultra-clean workbench. According to the operation structure, it can be divided into two forms: unilateral operation and bilateral operation. According to its purpose, it can also be divided into ordinary ultra-clean workbench and biological (pharmaceutical) ultra-clean workbench.
1. Working principle
The principle of the ultra clean workbench is that in a specific space, the indoor air is initially filtered by a pre filter, compressed into a static pressure box by a small centrifugal fan, and then filtered by a secondary air efficiency filter. The clean airflow blown from the air outlet surface of the air efficiency filter has a certain and uniform cross-sectional wind speed, which can eliminate the original air in the working area, take away dust particles and biological particles, to form a sterile and highly clean working environment.
2. Product classification
From the airflow direction, it can be divided into: vertical flow ultra clean workbench and horizontal flow ultra clean workbench; From the perspective of the number of operators, ultra-clean workbenches are divided into single person workbenches and double person workbenches; The ultra clean workbench is divided into conventional type, new type push-pull type, and self circulating ring type (vertical and direct current only) in terms of structure.
According to the direction of air flow, ultra-clean workbenches are divided into vertical flow clean benches and horizontal flow clean benches. Vertical flow workbenches have high noise due to their fans on the top, but vertical wind blowing is often used in pharmaceutical engineering to ensure human health; The horizontal flow workbench is relatively quiet, so it is often used in the electronics industry, with little impact on physical health. According to the operation structure, it can be divided into two forms: unilateral operation and bilateral operation. According to its purpose, it can also be divided into ordinary ultra-clean workbench and biological (pharmaceutical) ultra-clean workbench.
3. Precautions
The power supply of the ultra clean table mostly adopts three-phase four wires, including a zero wire that connects to the machine casing and should be firmly connected to the ground wire. The other three wires are all phase wires, with a working voltage of 380V. There is a certain sequence in the three-wire connection circuit. If the wire ends are connected incorrectly, the wind will reverse, and the sound is normal or slightly abnormal at this time. There is no wind on the front of the ultra-clean table (use the alcohol lamp flame to observe the movement, and it is not advisable to try it for a long time). The problem can be solved by promptly cutting off the power supply, and only changing the positions of any two wire ends before connecting them. "If the three-phase line is connected to only two phases, or if one of the three phases has poor contact, the machine sounds very abnormal, and the power should be immediately cut off for careful maintenance, otherwise the motor may be burned.". These common sense should be clearly explained to the staff when starting to use the ultra clean table, avoiding accidents and losses.
The air inlet of the ultra clean table is at the bottom of the back or front, and there is a common foam plastic sheet or non-woven fabric in the metal mesh cover to block large particles of dust. It should be checked and disassembled frequently. If the foam plastic is aging, it should be replaced in time. In addition to the air inlet, if there are air leakage holes, they should be tightly blocked, such as applying adhesive tape, cotton, adhesive paper, etc. The metal mesh cover on the front of the workbench contains a super filter, which can also be replaced. If it is used for a long time, dust particles are clogged, and the wind speed is reduced, which cannot ensure sterile operation, it can be replaced with a new one.