VNA-SDN Series – Design for explosive and combustible dust collection –

Combustible dust is one of the most serious risks in most manufacturing plants. When the explosive dust becomes the right concentration of oxygen and contact with a source for ignition will trigger a dust explosion. a dust explosion can occur in many areas of manufacturing plants, but one of the most possible locations is the dust collector. That’s because dust collectors keep airborne dust in the limited to a particular space. An explosion in an unprotected dust collector can blast the dust collector body and sends fire, pressure, and dangerous projectiles into the workplace. This can critically injure personnel. Therefore, if you need to collect explosive dust, dust collectors should have the prevention and protection function of dust explosions.

Anti-electrostatic woven filter

Manual shaking type

Inflammable powder/dust that might explode

Max. airflow

Premium efficiency motor/Dust explosion-proof motor

Features:

FULFILLING SAFETY MEASURES.DUST COLLECTOR FOR EXPLOSIVE AND FLAMMABLE DUST.

  • Designed to provide a high level of safety during collection of potentially hazardous particles.
  • Explosion pressure diffusion port(pressure from explosion is discharged into air to prevent damage to the equipment).
  • Extinguisher port (in the unlikely event fire occurs in the equipment, extinguishing agent is dispensed).
  • Check valve (prevent reverse flow of blow force or fire to protect the worker).

Anti-electrostatic filter

Material: Antistatic Tetron Felt + Aluminum + Earth
Surface treatment: Metal wire net weaving
Corresponding models: VNA-SDN/DN
Application: electrification characteristic dust
Others:  Aluminum sheet and Earth

Finefil Antistatic filter is avilable

 

Dust and powders that might cause explosions

- Magnesium
- Aluminum
- Aluminum light alloys
- Iron powder (non-oxidized)
- Epoxy Resin
- Cornstarch
- Titanium
- Toner
- Coal Dust
Other inflammable powders

Three conditions leading to dust explosions

1. Oxygen
2. Dust in a concentration higher than the explosion lower limit threshold
3. Minimum ignition energy

Dust explosions occur when the 3 conditions of “oxygen,” “Dust concentration higher than explosion threshold,” and “minimum ignition energy” are all present. If even just 1 of these conditions can be eliminated, then dust explosions can be prevented. So the crucial point in preventing explosions is eliminating sources of sparks. Also, we need safety measures to protect your staff and facility from dust explosions, just in case.

Dust Explosion Prevention and Protection

Dust explosion-proof motor

Electric motors, for instance, involve moving parts that can cause sparking. Dust explosion-proof motor is designed to prevent the invasion of the outside substances and is designed to eliminate risks of sparks.VNA-30SDN and VNA-45SDN have mounted the motor.

Aluminum fan casing, impeller, and producer

Aluminum fan casing, impeller, and producer have mounted on the VNA-SDN series. It prevents to have sparks generated by the fans.

Anti-electrostatic woven plate filter

Static electricity will make spark and could be ignition energy of dust explosion. Anti-electrostatic woven plate filter employs metal thread is woven into polyester technology and the filter has a strong and long time antistatic effect and reduces the possibility of generating spark cause by static electricity.

Conductive paint

Countermeasures against the problem of a dust explosion caused by static electricity are indispensable. The antistatic coating Conductive paint is effective in preventing static electricity by painting on metal and plastic. The conductive paint prevents the spark inside the dust collector and dust explosion.

Sealed electric control panel

Sealed electric control box is designed to structure that does not give triger of dust explosion.

Earth bonding

Eath Bonding is used to reduce the risk of electric sparks by connecting bonding conductors between particular parts, it reduces the voltage there might have been.

Fire extinguishing port

In case of fire in the dust collector, the fire extinguishing port is designed to load Fire extinguishing agent in to dust collector.

Check Valve

Explosion isolation check valve is to safeguard the surrounding workers as well as machinery. Explosion isolation involves stopping an explosion energy through the duct to suction point. the aim of the check valve is to stop blast explosion power from traveling throug duct.

Explosion pressure diffusion port

Explosion pressure diffusion port is designed to be the “weak” area of the dust collector body, an Explosion pressure diffusion port opens when predetermined pressures are reached inside the collector, allowing the excess pressure and flame front to exit to a Explosion pressure diffusion port. It is designed to minimize damage to the dust collector and prevent it from blowing up in the event of a deflagration, thereby reducing the safety hazard.

Kst and Pmax value

Model Kst value Pmax
VNA-30SDN 700 11.5
VNA-45SDN 700 11.5
VNA-60DN 300 11.0

The above Kst and Pmax value was covered calculated based on “Japan Explosive pressure discharge device technical guidelines(Revised version)NllS-TR-No.38(2005) in incorporated agency industrial safety institute laws. The above figures are for standard equipment. Please evaluate your target dust for explosion potential (option: dust powder explosion evaruation service are available)

Internal design

Dimension

Unit: mm

Specification

Particular Unit VNA-30SDN VNA-45SDN VNA-60DN
Power Supply Volt 220 220 220
Frequency Hz 60 60 60
Phase 3P 3P 3P
Output kw/hp 1.5/2 2.2/3 3.7/5
Max Airflow m³/min 25 40 55
Max. Static Pressure kPa 2.55 2.63 2.64
Filter Area 9.0 13.5 18.0
Suction Port Ø mm 150 200 200
Dimension (WxDxH) mm 1020x1253x1754 1355x1328x1821 1546x1396x2055
Weight kg 340 400 460