Air supply method
The purification table provides clean airflow through high-efficiency filters, which are mainly divided into two designs: horizontal air supply and vertical air supply. Horizontal air supply refers to the airflow parallel to the worktable and blows from the opposite side of the operator to the operating area; Vertical air supply refers to the airflow flowing perpendicular to the work surface from the top to the bottom. There are differences between the two in terms of airflow organization, operating space and applicable scenarios.
Differences between airflow patterns and protected objects
The horizontal supply of air flows directly to the operator, primarily protecting the experimental sample but may expose the operator to potential aerosols. The vertical air supply forms a laminar vertical barrier that typically protects both the sample and the operator as the airflow carries particulate matter down the breathing zone.
Select Consideration
The selection should be based on the needs of the experiment. The following comparison is based on a typical design:
| Horizontal air supply | Vertical air supply |
| The airflow parallels the countertop | The airflow is vertically downward |
| It is suitable for large equipment placement | Less obstruction of the front view |
| Commonly used for sample protection | Commonly used personnel protection scenarios |
| The depth of the working area is affected by the attenuation of the airflow | Work area uniformity is usually high |
The airflow velocity v needs to meet the cleanliness requirements, usually maintained in the range of 0.3~0.5 m/s, which can refer to the formula v = Q/A, where Q is the air supply volume and A is the effective area of the filter.
Summary
The core difference between horizontal and vertical air supply and purification tables is the direction of the airflow and the protection it brings. The horizontal air supply focuses on sample protection and facilitates the placement of taller instruments, while the vertical air supply provides sample protection while enhancing operator protection. The actual selection should be judged comprehensively based on the type of experiment, sample characteristics and safety specifications.
References: Technical Guide to Laboratory Cleaning Equipment; the principle of air purification technology; Comparative analysis of biological safety cabinet and purification workbench standards.