Instructions for biological safety cabinets | Operation principle of safety cabinets

January 10, 2022

working principle

The working principle of the A2 biological safety cabinet: the air enters the negative pressure air channel from the front fresh air port and is fully mixed with the air in the cabinet, and then is sent into the static pressure box by the fan. The left and right walls of the operation area and the rear wall are negative-pressure air ducts, which form a double separation of the air curtain and the box from the external environment. At the same time, the working area is surrounded by negative pressure to ensure that the sample does not leak. The airflow in the operating area is mixed with the air entering the fresh air vent through the negative pressure air duct due to the effect of the exhaust fan. Part of the mixed gas (about 30%) is sent by the fan It is recycled into the static pressure box, and the remaining mixed gas (about 70%) is filtered through the exhaust air high-efficiency filter and discharged out of the cabinet.

The working principle of the B2 biological safety cabinet: After the air is filtered by the pre-filter, it is sent into the static pressure box by the fan, and then enters the operation area after being filtered by the high-efficiency filter. The left and right walls of the operation area and the rear wall are negative-pressure air ducts, which form a double separation of the air curtain and the box from the external environment. At the same time, the working area is surrounded by negative pressure to ensure that the sample does not leak. The airflow in the operation area is filtered by the exhaust air high-efficiency filter through the negative pressure air channel and discharged into the exhaust gas channel due to the effect of the exhaust fan.

Operating environment and conditions

Temperature: 5 ℃ ~ 35 ℃

Relative humidity: not more than 85% (at + 35 ℃)

Atmospheric pressure: 86KPa ~ 106KPa

Maximum dust concentration: 3500 particles / L (dust particle size is not less than 0.5μm)

Power supply: 220V ± 10%, 50HZ ± 2HZ

Installation adjustment

1. The biological safety cabinet should be placed in a clean workshop or a relatively clean environment.

2. The place where the biological safety cabinet is installed should be far away from dust and earthquake sources.

3. During the unpacking and seating of the biological safety cabinet, it should be handled with care, and collision or tipping is strictly prohibited.

4. Read this instruction manual carefully before starting work.

Use operation

1. The power supply of the biosafety cabinet is 220V, 50Hz, and there is a grounding sign below the rear of the cabinet. It must be reliably grounded before use to ensure safety. The biosafety cabinet is equipped with a fuse and is located at the lower right end of the cabinet Next to the exit is the fuse for the total power supply of the device.

2. Before use, please check whether the power supply of each part is connected well. If there is an external exhaust fan, please check whether the external exhaust fan is installed.

3. Turn on the power and press the [Power] key on the control panel, the system is powered on and enters the standby state.

4. Press the 【Sterilization】 button, turn on the UV lamp for 30 minutes and then turn off the UV lamp. (Note: The glass door should be closed at this time)

5. Open the glass door to the sign.

6. Press the [Fan] button to turn on the fan for about 15 minutes to make the operation area reach the specified cleanliness.

7. Press the [Illumination] key to turn on the lighting lamp before the operator can start work.

8. After the work is completed, the fan and glass door should be closed, and the ultraviolet lamp should be turned on for 30 minutes to kill the bacteria remaining in the safety cabinet.

9. Turn off the UV lamp, open the glass door, and clean the work surface.

10. Turn off the power.

maintenance

1. The operator should carefully read the instruction manual of the safety cabinet and strictly follow the requirements in the instruction manual.

2. Routine maintenance: run the safety cabinet according to the power supply, check whether the functions of each part of the safety cabinet are normal; wipe the surface of the equipment and the operation area with detergent to dissolve in water; clean the box with flexible detergent or special glass cleaner In vitro surface and glass; sterilize the operation room.

3. Regular maintenance: conduct a comprehensive inspection of the equipment every three months and maintain it carefully. Completely clean the equipment and disinfect and sterilize; check whether each part is flexible in opening and closing; check whether each part is functioning normally.

4. Generally, when the working voltage of the fan is adjusted to the highest point after the use of 18, the ideal wind speed is still not reached, it means that the high-efficiency filter has too much dust (the filter hole on the filter material has been basically blocked, and it must be updated in time) In general, the service life of high-efficiency air filters is 18 months.

5. When replacing the high-efficiency air filter, pay attention to the correctness of the model specifications (original manufacturer configuration), according to the arrow wind direction device, and pay attention to the perimeter seal of the filter, absolutely no leakage occurs.

Special note: The replacement and maintenance of electrical components must be carried out by qualified electricians under safe conditions.

General failures, causes, and troubleshooting

Fault phenomenon

the reason

Discharge method

The main power switch fails to close and automatically trips

1. The fan is stuck causing the motor to stall or the circuit is short-circuited

1. Adjust the position of the fan shaft, or replace the impeller and bearing, and check whether the circuit is intact.

2. According to the circuit diagram, check the insulation resistance of the circuit and components to the housing point by point to repair the insulation failure.

Low wind speed

1. The high efficiency filter is invalid.

1. Replace the high-efficiency filter.

The fan does not rotate

1. The contactor does not work.

2. The fan power fuse has blown.

1. Check whether the contactor circuit is normal.

2. Replace the core.

Fluorescent light is not on

1. The lamp or relay is damaged.

2. The fuse of the lamp power supply has blown.

1. Replace the lamp or relay.