Principle and technical parameters of ultra-clean workbench

Principle and technical parameters of ultra-clean workbench

Fundamental

1

The ultra-clean workbench is designed to accommodate modern industrial, optoelectronic, biopharmaceutical, and scientific research experiments. It is designed to protect RNA and DNA samples from contamination during the experiment.

2. The working principle is that the indoor air is sucked into the cabinet by the fan through the HEPAH14 filter, and is discharged out of the cabinet through the operation hole. The discharged air directly faces the operator, avoiding the operator from contaminating the experimental sample.

a:

, technical advantages:

1. Digital display timer, large screen LCD display, pre-set UV sterilization time, customers can set the sterilization time according to their needs.
2. Large LCD screen displays surface wind speed, wind speed is too high or too low alarm reminder.
3. The fan speed can be adjusted by itself. As the HEPA filter increases with the use time, the pressure loss will become larger. To ensure the safe surface wind speed, the CPU monitors the surface wind speed too high or too low to adjust itself and achieve the safety value.

Filter: HEPA filter: For particle filtration, the filtration efficiency is 99.995% for particles larger than 0.3um

HEPA filter          

Performance parameter

Control part of Huafeng products

Huafeng online detection system - patented technology

1 , What is online monitoring system?

Huafeng Company's pipeline-free clean air fume hood and medicine cabinet come with an on-line monitoring system that can monitor the TVOC value of the filter outlet and display it on the LED screen, while monitoring the TVOC value in the chemical laboratory and displaying it in the LED. On the screen. This system allows users to know the saturation of the filter of the clean gas product they use, as well as to understand the air quality in the laboratory, to ensure the safety of users and to prevent unknown dangers and hidden dangers.

2 , background

Adopting high-sensitivity electrochemical probe imported from Japan, combined with chemical experiment

Software design of the complex situation of the room, after numerous tests,

When acetone is used as the reference substance, it is consistent with the PID data, and the error is less than

5%.

3 , working principle

A. The sensitive material of the gas sensor is metal oxide. The most representative one is SnO2. When it is heated to a certain high temperature in the air, oxygen is adsorbed on the surface with a negative charge, and then the surface of the crystal is supplied with electrons. Transferring to the adsorbed oxygen results in a positive charge in a space charge layer. This surface potential creates a barrier that blocks electron flow.

B. Inside the sensor, current passes through the bonding sites (grain boundaries) of the SnO2 crystallites. At the grain boundary, the adsorbed oxygen forms a barrier to prevent the carriers from moving freely, and the sensor's electricity is due to this barrier. When a reducing gas occurs, the surface concentration of the negatively charged oxygen decreases, resulting in a decrease in the barrier of the grain boundary. Thereby reducing the resistance of the sensor.

4 , TVOC: Total Volatile Organic Compounds

TVOC : Total Votatile Organic Compound

It refers to a general term for various chemical organic compounds which can be volatilized into a gas at normal temperature, and the main components thereof are alkane, aromatic hydrocarbon, alkene, halogen, ester, aldehyde and the like. Irritating to the eyes, respiratory system, harming the liver, kidneys, brain and nervous system.

The laboratory TVOC is very complex and usually contains many traces of chemicals that cannot be detected by existing detection methods.

5 , Alarm value setting

Huafeng Technology's online monitoring system uses dual probes, one probe to monitor the laboratory environment and the other probe to monitor filter saturation.

OSHA (American Occupational Safety and Health Association), ACGIH (United States Government Industrial Hygienist Conference) stipulates that the TLV value of acetone is 300ppm.

For the saturation point setting of the filter, Huafeng Technology uses 1% TLV, which is 3ppm. For laboratory environments, the recommended value is 3ppm, user

It can be set according to its actual situation and requirements.

6 , Huafeng product safety performance

• The Huafeng product standard prepares a two-layer molecular filter, and the filter saturation monitoring probe is placed between the two-layer molecular filters.

• When the on-line monitoring device detects that the filter is saturated and gives an audible and visual alarm, the trace amount of chemical gas will be filtered by the second layer filter, so the gas coming out of the product outlet is chemical-free. .

• When the first layer filter is saturated, the Huafeng Technology second layer filter can be used continuously, and the newly replaced filter can be placed on the second floor, so the customer only needs to replace one filter at a time.

7 , check

• Huafeng Technology has developed a fully automatic calibration instrument with independent intellectual property rights. It uses PID as the benchmarking instrument, acetone is the calibration chemical, and the point-to-point calibration is performed with an error of less than 5% and good repeatability.

• For the online monitoring system sold, in principle, it will be verified once every two years. The Huafeng technical engineer will replace the probe to be verified and issue a verification report.

• Conditional customers can also use acetone as a volatile gas, and compare them with a gas chromatograph and PID.

8 , monitoring system stability

• The probe supplier is a globally renowned brand.

• The figure below shows the long-term stability data of the probe provided by the manufacturer.