Air Hoists / Pneumatic Hoist
Air hoists or pneumatic hoists use pneumatic air systems to operate instead of electrical power. Pneumatics is a branch of engineering which uses compressed air. So an air compressor unit sucks in atmospheric air and usually removes the naturally occurring moisture from it. Consequently the dry air is then pushed through pipes to power the air chain hoist.
Where can Air Hoists be used
Handy, flexible and universally deployable, an air hoist make the ideal tool for lifting and handling and manufacturing applications. An air hoist is commonly utilised in many industries including assembly lines, aircraft construction, shipyards and engineering.
Pneumatic hoists can also be used in areas which could be deemed hazardous to use electric hoists. Such places could include power plants, chemical plants, paint shops, oil refineries, foundries, mines and oil storage facilities.
Advantages of Pneumatic Hoists
- An air chain hoist typically has duty cycles of 100%. Consequently there is no need for a rest period as minimal heat is produced due to the air power.
- The simplistic design of these pneumatic hoists use cylinders and other components, with easy operation using on-off control functions.
- Low maintenance and long life operation due to minimal components is a key benefit to pneumatic hoists.
- Resistant to dirt and dust ingression; Impervious to heat, vapours, high temperatures and humidity.
- Less likely to experience shock damage due to the use of compressed air.
- Very low fire risk
- Air hoists commonly incorporate an overload device for additional safety.
- Light in weight – up to 40-50% lighter than similar electric hoists.
- Cleaner to operate with low environmental impact.
- Braking systems incorporated.
- Can be used in hazardous environments
Using A Pneumatic Hoist
Air chain hoist, or pneumatic hoists normally use a pendant type control box with simple up and down control buttons. As a result, operation is straight forward.
These hoists should be operated by trained personnel and are to be used for lifting loads/materials. However they should not be used to lift people.
Pneumatic hoists which are used outside should be protected from the elements. Therefore it is very important to regularly check your air hoist and its components. Also including the air hoist compressor unit for potential operating problems. Most importantly always follow compressed air usage guidelines. Daily checks of the braking system, emergency stops, and lifting / lowering limits should be carried out. As a result of complying with regulations and carrying out these checks you can ensure safety and longevity.
Air hoist Chains should be checked and re-lubricated on a monthly basis. And all other parts and components should be thoroughly inspected at least on a yearly basis by trained inspection engineers.
Most importantly you should never use an air chain hoist in certain areas such as nuclear plants (critical areas) or where organic acids or corrosive materials are present, nor over acid baths.
Air hoists normally use 4 bar or 6 bar air pressure, this helps avoid underperformance or overloading. The air supply must always be well maintained. For instance they should be dry, clean and free-flowing for the air hoist to operate unhindered.
Here are some useful pressure and air flow conversions;
Kilograms per square cm x by 14.226 to get pounds per square inch (PSI)
Bar x by 14.503 to get pounds per square inch (PSI)
Pounds per square inch (psi) x by 0.6984 to get Bar
Pounds per square inch (psi) x by 0.0703 to get kilograms/cm²
Cubic foot per minute (cfm) x by 0.02832 to get cubic metres per minute (m3/min)
Cubic foot per minute (cfm) x by 0.4719 to get Litre per second (l/sec)
Litre per second(l/sec) x by 2.118 to get cubic foot per metre (cfm)
Litre per second (l/sec) x by 0.001 to get cubic metre per second (M3/sec)
Cubic metre per minute (M3/min) x by 16.6666 to get Litre per second (l/sec)
Cubic metre per minute (M3/min) x by 35.3146 to get Cubic foot per minute (cfm)
What to look out for when purchasing
There are certain features which all good quality pneumatic hoists should incorporate. They should include safety elements like load brakes, emergency stop devices and shock loading protection. But should also include upper & lower limit switches and hooks with safety catches.
Other good features of an air hoist include; variable speed control, choice of control device, planetary gearboxes, vane motors. As well as integrated trolleys, low noise levels, self-cooling motors, main air valve shut off features and quality calibrated load chain.