Self-excited continuous periodic mechanical vibrations of compressor, fan and pump mainly have an effect on refrigeration equipment (water-cooling refrigerating machines (chillers), autonomous central air-conditioners, condensing units, compressor and receiver units and others), operated in stationary conditions.
For example, in ship conditions, pitching and rolling motion, and vibration of main power unit, propellers and others, exert influence on refrigeration equipment operated on sites, liable to mechanical effects. And in emergency situations there are impact actions.
In view of above-mentioned, when designing refrigeration units it is necessary to consider vibration factor. At project stage, the design of shock absorption system, which includes support cascade of shock absorbers (fastening of equipment to foundation), intermediate cascades of shock absorbers (fastening of compressors, fans and pumps), vibration insulating inserts (flexible hoses), is very important. This article contains the information about vibration insulating inserts.
Depending on operation conditions, the vibration absorber is installed on compressor discharge and suction lines in horizontal plane to dampen vertical and transversal vibrations. Additionally, if necessary, the second vibration absorber is installed in vertical plane to dampen linear and transversal vibrations. It is required to install vibration absorbers in close proximity to compressor discharge and suction branch pipes.
Vibration insulating inserts are applied for the following:
- preventing of overlimited deformations along refrigeration unit pipelines during compressor operation;
- additional reducing of compressor-induced vibration level;
- compensation of temperature and mounting deformations;
- leveling of compressor-induced pulsations on discharge line.
Example 1. Installation of vibration insulating inserts in suction line and discharge line of refrigeration unit based on scroll compressor
Example 2. Installation of two vibration insulating inserts in suction line and discharge line of refrigeration unit based on scroll compressor (Figure 2, 3)
In these examples vibration insulating inserts manufactured by New Donghae of VAS series have been used as component parts. Vibration absorbers elements are produced from the following materials: corrugated pipes, braid, serrated insert and tip – from stainless steel of 304 grade (as per AISI), fitting end for nut– from copper. The distinctive feature of New Donghae vibration absorbers construction is installation of inner and outer tip for protection from overheat during mounting. When installing vibration insulating inserts in pipeline there can be excessive overheat with burner during soldering and consequently there can be observed the reduction of vibration damping. When installing vibration absorbers of such type, the risk of vibration damping reduction from overheat is minimal during installation.