Subject Area

Systems Engineering / Pressure Equipment

Start


Virtual Exhibition presents:

Please click on the Logo to open the company presentation in our Yellow Pages.

Virtual Exhibition


GHS Expert

Compressed Air

Everything you need to know about compressed air:
summarized by netinform and our partner BAUER KOMPRESSOREN GmbH München

Compressed Air
Compressor Types
Compressor Installation
Laws, Regulations, Technical rules
Indoors
Indoors

Indoor installation of air-cooled compressors

Indoor installation of air-cooled compressors
To ensure smooth operation of air-cooled compressors, the following points must be observed when compressors are installed indoors:
     
  • the room must be clean, free of dust, dry and as cool as possible;
  •  
  • direct sunlight should be avoided. If possible, the compressor should be installed on the northern side of the building;
  •  
  • sufficient ventilation must be ensured. Room temperature = cooling temperature! Min. +5°C, max.+45°C. At temperatures < 5°C, the room must be heated.

One differentiates between two types of ventilation:

Natural ventilation
Natural ventilation is the simplest form of ventilation and results automatically from heating and cooling. Unless thermal overloads are to be expected, natural ventilation is sufficient. It is suitable for light-duty compressors, intermittent operation and areas with moderate climate. The intake and discharge openings depend on

     
  • the power of the electric motor
  •  
  • the difference in height between the intake and discharge opening
  •  
  • the air volume in the compressor room

The dimensions of the respective openings are included in special tables and installation manuals together with alternative forms of compressor installations.



Installation with natural ventilation

Artificial ventilation
Normally, artificial ventilation is only required, if the motor output exceeds 15 kW, if the compressor is to be installed in a small room, if the cooling air openings cannot be adequately dimensioned or if several compressors are accommodated in one and the same room.
For further information please refer to the specific manuals.



Installation with artificial ventilation

It must be especially emphasized that in cases involving cold intake air (winter operation), this air must always be pre-warmed to avoid deficient drive lubrication because the oil is too cold. The intake air can be pre-warmed via a suitable forced-air system that can easily be mounted on the compressor. Large compressor systems require an appropriate intake and discharge air duct and a forced-air system that is adjusted to the compressor type.

Contents by
BAUER KOMPRESSOREN GmbH München

Outdoors
Outdoors

Outdoor installation of air-cooled compressors

Provided the following criteria are taken into account, air-cooled compressors may also be installed outdoors:
ensure protection against rain and direct sunlight (installation below an arbor, canopy, etc.)

For winter operation, compressors are best installed in a 10 or 20' thermally insulated container. A stationary heating unit including a forced-air system should be provided for targeted ventilation of the compressor and the container. This will also prevent freezing of the condensate valves and the condensate. The cooling openings are provided with flutter blinds or louver controls and are protected by a bird screen on the outside. Additional discharge and intake-air ventilators should be provided for larger compressors.

A big advantage of air-cooled compressors is that they require no cooling water and thus do not involve the risk of the supply lines etc. becoming iced up in winter.

Contents by
BAUER KOMPRESSOREN GmbH München
Sound insulation
Sound insulation

Sound insulation

To avoid hearing impairment, the sound pressure emitted by a machine or a high-pressure compressor must be reduced by suitable means. This applies, in particular, if compressors are installed in workshops or laboratories where man and machine are under one roof.
In these cases, the entire compressor system requires a soundproofed casing that encloses all filters, inlet and discharge-air openings as well as any additional blowers, e.g. that may be needed for larger compressors. At the same time, it is important that all parts of the compressor requiring maintenance can be easily accessed during servicing. The sound-pressure level is measured and recorded as per German standard DIN 45635, part 1.

Contents by
BAUER KOMPRESSOREN GmbH München
Compressor control
Compressor control

Compressor control

For high-pressure reciprocating compressors one differentiates between two modes of operation
     
  • semi-automatic
  •  
  • fully automatic (start-stop control)

Semi-automatic operation is typical of small, high-pressure compressors used to fill diving cylinders. The compressor is switched on manually and once the filling pressure (200 bar or 300 bar) is reached, the compressed air is either expanded again via the final pressure safety valve into the open air or automatically switched off via a pressure switch or sensor. Compressors for industrial applications are mainly operated fully automatically. For example to periodically apply compressed air to a test specimen, the compressed air must be held ready in an interim storage container. A pressure sensor will automatically switch on the compressor at a preset minimum container pressure and switch it off again once the final pressure has been reached. At the same time, steps must be taken to ensure that the compressor is depressurized at startup. This is effected by an automatic condensate drain with an integrated device to depressurize the compressor at startup.

Contents by
BAUER KOMPRESSOREN GmbH München

Ex-safety
Ex-safety

Explosion safety

Specific compressed air applications (e.g. in UREA production, in the chemicals industry etc.) require ex-proof design of the compressor drive and the compressor control system if the compressors are positioned at places where an ignitable gas/air mixture may develop from time to time during standard operation.

Contents by
BAUER KOMPRESSOREN GmbH München
Tubing
Tubing

Tubing

The stainless steel tubing materials 1.4541 or 1.4571 have proved highly suitable for the tubing network of a compressor system including compressed-air processing, storage and distribution to the consumer. The advantage of these materials is that corrosion cannot occur at any time and that flow resistance is low. Owing to the high pressure, a very small cross section may be selected for the tubing, so that material costs are much lower than for tubes with large cross sections. The outside diameters of the tubes range from 8 to a max. of 20 mm depending on pressure, throughput and distance. Tubing must be dimensioned such as to keep pressure losses within narrow limits. The maximum pressure loss should not exceed approx. 0.1 bar, and this must be taken into account at the planning stage.
As connecting element for coupling the compressor to the tubing, the cutting-ring coupling has proved highly suitable both in industry and in the breathing air sector.
Disadvantage: this coupling may start to leak after it has been unscrewed and screwed together again several times.

For tubing that is required to be highly leakproof, a stainless steel Swagelok coupling is recommended. With this coupling, leakage does not occur even after the coupling has been unscrewed and screwed together again several times. However, it is far more expensive.

Contents by
BAUER KOMPRESSOREN GmbH München