Contrary to how the name sounds, Flame Proof Elevators are not the Elevators that can run through flaming floor and not be affected by it. However, the Flame Proof Elevators are Elevators with Components that do not allow flame to exist or occur or move out of the enclosure where it has started.
Below are some of the details we have mentioned about the flame proof Elevators, The Environment in which they are used, etc
- What are Flame Proof Elevators?
- Why do you need Flame Proof Elevators?
- Where do you need Flame Proof Elevators?
What are Flame Proof Elevators?
Flame Proof Elevators are Elevators which has components that do not create flame or even Sparks or or has enclosures for components which contain the spark by isolating the spark from the outside environment which may be flammable.
In a Flame Proof Elevator, generally, all the electrical components of the elevator are enclosed in a flame proof enclosure. A flame proof enclosure is generally a heavy duty aluminium or steel die cast enclosure which is totally enclosed with multiple bolts to isolate the contents in the enclosure from the external environment. All the holes meant for the cable entry use special flame proof cable glands to ensure that there is a tight fit between the cable and the enclosure thereby preventing any air exchange.
Due to the isolation of the Elevator components, the electrical equipment which may produce small sparks do not travel outside the enclosure. These enclosures and manufactured and used for many devices including motors, electromagnetic Solenoid, Limit Switches, Cable connections, etc.
Purging as a method of Flameproofing
Some equipment’s, generally electric panels, use a system called purging to make the enclosure flame proof. This is a different as compared to the Standard Flame Proof Enclosures.
So what is Purging? Purging is to have the enclosure required to be flameproof at a Positive Pressure as compared to the outside Pressure. Generally, the Enclosure is airtight or nearly air tight and there is an inlet into the enclosure which will carry the gas into the enclosure at a pressure more than the atmospheric pressure. The gas may be fed by using Pressurized cylinders or may be directly connected to a pressuring unit. Nitrogen gas is generally used as the gas for purging as it does not feed the flame.
Purging is used to keep the hazardous gas out of the enclosure by ensuring a positive pressure in the enclosure. This way the Hazardous gas or dust does not enter the enclosure and hence in the even of a spark or flame, the flame does not come in contact with the explosive gas or dust. As the nitrogen gas is used the flame is extinguished almost immediately as oxygen is not available for the flame to continue burning.
Why do you need Flame Proof Elevator?
The Elevator may be situated in the area which has flammable gas or dust or when the content of the goods carried in the elevator are unstable and flammable. Some Industrial Buildings where chemicals are handled need the certification from third Party and for such certification, a flame proof elevator may required.
When the Elevator is situation in a area which has flammable gas or dust, any spark in the elevator component may lead to a fire in the whole building. To prevent such a situations the elevators components are carefully enclosed in the flame proof enclosures.
When all the electrical components which might create a flame or spark are enclosed so that it is isolated from the outside environment, the elevator is known as flame proof elevator.
All the Explosive Environment have auto ignition temperature where the heat from the equipment will lead to ignition of the gas or dust in the environment. The Environments are this classified in 6 ranges from T1 to T6. The Maximum Surface temperature of the working components must be maximum of 80% of the Environment Temperature Class.
The Electrical components are thus rated for various Temperature Ranges. This is to ensure that the Temperature of the Working components are always under the auto ignition temperature of the environment with a safe margin (about 20%).
In a flame proof elevator care must be taken to ensure that sparks are not created by grinding of metal objects during the working of the elevator as this would be completely contrary to the objective to prevent flames.
Where do you need Flame Proof Elevator?
Flame Proof Elevators are used in industrial setting where the environment has unstable and flammable gas or dust and such gas may also have a auto ignition temperature.
The main industries that use flame proof elevators are Chemical Industries, Pharmaceutical Industries, Fertilizer Manufacturers, Space Exploration and Rocket Testing and Manufacturing Industries, Oil and natural Gas Industries. Other than these industries there are industries that have flammable dust, these also use flame proof elevators. All these industries have to deal with flammable gas, vapour, dust, etc.
Below is a Video of Flame Proof Elevator in Working Condition Showing the Flame Proof Enclosures.