Complaint
Most fume hoods share common design characteristics. High performance fume hoods incorporate additional or modified components. The basic fume hood components include the hood body, sash, work surface, exhaust, and baffles.
1. Hood Body
The housing of the fume hood provides the containment for hazardous gases and vapors or the physical barrier between the containment and the outside air.
2. Work Surface
The work surface or deck is generally a laboratory bench top.
3. Exhaust Plenum
The shape and location of the exhaust plenum helps to distribute air flow evenly across the hood face. Materials such as paper towels drawn into the plenum can create turbulence in this part of the hood, resulting in areas of uneven air flow and poor performance.
4. Air Foil Sill
The air foil sill is located along the bottom edge of the fume hood. The air foil performs several important functions:
• It streamlines the airflow into the hood around the edge, reducing turbulence and loss of containment,
• The flow continually sweeps the work surface, and
• It provides a source of air for the hood to exhaust with the sash fully closed.
| Model Specification | WJ-1500A | WJ-1500B | WJ-1800A | WJ-1800B |
| External dimensions of equipment(mm) | 1500(W)*1205 (D) *2400 (H) | 1800(W)*1205 (D) *2400 (H) | ||
| Dimension of works pace (mm) | 1260(W1)*780(D1) *1100 (H1) | 1560(W1)*780(D1) *1100 (H1) | ||
| Panel material | 20+6mm thick butterfly ceramics | |||
| Material of internal lining board | 5mm thick ceramic fiber board | |||
| Diversion structure | Lower air return | |||
| Control system | Button control panel (LCD panel) | |||
| PH value control | The medium is alkaline water solution; manual monitoring, and manual control through acid pump and alkali pump. | |||
| Input power | Three-phase five-wire 380V/50A | |||
| Current for air fan | Not over 2.8A(380V or 220V can be directly connected) | |||
| Maximum load of socket | 12 KW(total of 4 sockets) | |||
| Water tap | 1 set (remote control valve + water nozzle) | No | 1 set (remote control valve + water nozzle) | No |
| Water discharge way | Magnetic chemical pump strong discharge | |||
| Using environment | For non-explosion indoor use, within 0-40 degrees Celsius. | |||
| Applicable fields | Inorganic chemistry experiment; Food, medicine, electronics, environment, metallurgy, mining, etc. | |||
| Ways of Purification | Spray sodium hydroxide solution, no less than 8 cubic meters/hour | Spray sodium hydroxide solution.no less than 12 cubic meters/ hour | ||
| Ways of surface air speed control | Manual control (through the electric air valve to adjust the exhaust air volume or adjust the height of the moving door) | |||
| Average surface air speed | 0.6-0.8 m/s Exhaust air volume: 1420-1890m3/h (when door height h =500mm) | 0.6-0.8 m/s Exhaust air volume: 1760-2340m3/h (when door height h =500mm) | ||
| Speed deviation of surface air | Not higher than 10% | |||
| The average intensity of illumination | Not less than 700 Lux; Standard white and uv-free yellow LED lamps; The illumination is adjustable. | |||
| Noise | Within 55 decibels | |||
| Flow display | White smoke can pass through the exhaust outlet, no overflow. | |||
| Safety inspection | No spikes, edges; Charged body and the exposed metal resistance is greater than 2 mQ; Under 1500V voltage, no breakdown or flashover occurred for 1min test. | |||
| Resistance of exhaust cabinet | Less than 160 pa | |||
| Power consumption | Less than 1.0kw/h (excluding power consumption of fans and external instruments) | Less than 1.2kw/h (excluding power consumption of fans and external instruments) | ||
| Water consumption | Less than 3.2L/ h | Less than 4.0L/ h | ||
| Performance of wind compensation | With a unique wind compensation structure, the volume of the wind will not cause turbulence in exhaust cabinet and will not directly blow to the staff (need to connect to the air compensation system of the laboratory) | |||
| Air volume regulating valve | 315mm diameter flanged type anti-corrosion electric air flow regulating valve (electric contact actuator) | |||
Fume hoods are a type of ventilation system used in many laboratories throughout the University. Their primary function is to exhaust chemical fumes, vapors, gases, dusts, mists, and aerosols. They also serve as physical barriers between reactions and the laboratory environment, offering a measure of protection against inhalation exposure, chemical spills, run-away reactions, and fires.
A typical fume hood has a box-like structure with a moveable sash window. Experimental procedures are performed within the hood which is consistently and safely ventilated, usually by means of an extract blower and ductwork. Chemical fumes are exhausted and diluted many times over in the atmosphere and have an insignificant effect on human health.
Fume hoods function by maintaining a relatively negative interior pressure while continuously drawing air through the sash opening, which prevents contaminants from escaping.
A suitable hood face velocity (the speed at which air is drawn into the hood) is critical to safe and effective operation. While excessive face velocities can result in turbulence and reduce containment, insufficient velocities also compromise performance.
In general, a hood's cubic face velocity is recommended to be between 0.3 m/s (60 cubic feet per minute) and 0.5 m/s (100 fpm).
• Hoods should be evaluated by the user before each use to ensure adequate face velocities and the absence of excessive turbulence.
• In case of exhaust system failure while using a hood, shut off all services and accessories and lower the sash completely. Leave the area immediately.6 Questions to Ask When Buying a Fume Hood:
-Which chemicals will you use within the hood?
-Is a ducted or ductless hood best suited to your needs and available space?
-Where will you place the fume hood in the lab? Consider workflows, access to external exhaust systems, and competing air patterns.
-What size fume hood will best suit your needs? Be sure to consider what (if any) equipment will be enclosed in the hood.
-Are any service fixtures or accessories such as airflow monitors, electrical outlets, water, or gas fixtures required?
-Are base cabinets for acid, solvent, or non-chemical storage required?
