An air receiver is a tank used to store compressed air. This component plays an integral part in ensuring proper functioning of compressor and pipe system components.
An air conditioning accumulator, often found in older cars equipped with thermal expansion valves or orifice tube systems, is designed to filter moisture out of refrigerant and monitor and control its flow.
Refrigerant Storage
An accumulator, like a receiver drier, serves as a liquid/vapor separator. While its counterpart prevents any vapor from leaving its unit and flowing into liquid line that leads to expansion valve, an accumulator allows a controlled amount of vapor through pickup tubes into suction line that runs to compressor.
As the accumulator is placed under vacuum, refrigerant vapor travels slowly through its internal desiccant material that absorbs and separates moisture from its refrigerant vapor stream. Moisture can damage system components as it passes through, so its elimination from circulation is an integral component to ensure its proper functionality.
The accumulator also features a small filter to block foreign matter from entering the orifice that controls oil return into the compressor, thus preventing blockages that would result in overheating and/or poor performance of its compressor. This feature is essential since foreign material could obstruct return, potentially restricting oil delivery into its intended destination and potentially leading to overheating or decreased performance from this machine.
An improperly functioning accumulator is another compelling reason to hire professional technicians to handle air conditioning maintenance and repair tasks. A technician will thoroughly examine it for moisture contamination as well as signs of wear that could compromise its performance, thus assuring optimal service from it.
Accumulator design is an integral component of modern air conditioning systems. While various models exist, their basic purpose remains the same: to store liquid refrigerant and prevent it from reaching the compressor. An accumulator should be located in the low pressure section after both evaporator and compressor to complete its job effectively.
The liquid storage capacity of an accumulator depends on its expected amount of floodback liquid that will occur, as determined by testing full system charges with it installed. An ideal accumulator would hold as much liquid as is anticipated while also featuring an orifice capable of dispensing an adequate amount of oil to support system needs; solder particles and foreign matter may clog this orifice, necessitating an inlet screen as protection; heat bands may also help evaporate excess fluid and facilitate oil return.
Moisture Removal
Moisture in compressed air can damage compressor equipment and diminish product quality, so it’s vital that any wet compressed air be drained regularly – typically once daily; but it may need to be done more frequently if your system runs continuously throughout the day.
Air receiver tanks that become saturated with moisture may start to corrode and require replacing or repair, leading to costly repair costs and replacement needs. One method for moisture removal is desiccant bags filled with silica gel which absorbs and removes humidity as air passes through, by being exposed to very low temperatures so as to cause it to condense into water droplets, then release this as waste through their pores.
Air compressors cannot remove moisture from compressed air on their own; as such, systems must include either an air dryer or an accumulator to ensure its quality before final production of compressed air products.
Receivers dryers and accumulators both perform the same function of extracting moisture from compressed air, consisting of an air tank, filter and desiccant bag. However, an accumulator typically outshines its counterpart.
CEMSs (continuous emission monitoring systems) are invaluable tools for analyzing airborne gas concentrations and particulate matter. Unfortunately, moisture contamination of samples can lead to artifact formation or absorption of target compounds that degrade measurement accuracy.
CEMS moisture mitigation methods include condensation and permeation – two of the most popular being condensation and permeation. Condensation uses a membrane tube equipped with an absorbent substrate cooled below dew point temperature; moisture is drawn into this structure through absorption by its cool temperature substrate and removed via adsorption. Permeation takes advantage of airflow through perforated membrane tubes that removes humidity through permeation processes; for permeation methods moisture can enter directly via inhalation into an ambient gas stream, while permeation involves airflow through pores in order to permeate through into sample gas streams of different temperatures; condensation also allows CEMS users to reduce moisture effects when inhaling sample gas streams, such as permeations methods use condensation; to this end moisture absorption by absorption by these substrates cooled below dewpoint; this removes moisture through absorption processes until finally it reaches dewpoint, leaving only trace amounts left behind on its side of course permeation involves more complex methods used on sample gas streams from such samples cooled substrate tubes; this method involves permeation membrane tubes with permeation membrane tubes with permeation processes similar to condensation process used on such streams while permeation is done through permeation involves permeation used during its own stream and permeation to removesits sample streams are applied depending on sample gas streams which has cool temperatures to remove it’s dewpoint.
Permeation is similar to condensation, except it uses a membrane instead of substrate as its base material. Although this approach is generally more efficient, permeation has some drawbacks that limit its use such as losing target compounds due to poor selectivity or producing too much dry gas in samples.
Pressure Control
An air receiver serves as a buffer to accommodate sudden spikes in demand by temporarily storing compressed air. Unlike an air accumulator, however, its air pressure can fluctuate on an ongoing basis within an air receiver. As part of its storage volume, a receiver tank, discharge piping and hoses also constitute the storage volume. A pressure-based pressure and flow controller may be installed after the receiver tank to help stabilize downstream pressure to 100 PSIG while simultaneously smoothing demand peaks. However, this requires an adverse volume flow from the control valve in order to achieve desired pressure reduction. An accumulator offers an alternative solution by storing hydraulic fluid for controlled release at desired pressures.
An accumulator consists of a cylindrical structure with two chambers separated by either an elastic diaphragm, fully enclosed bladder or piston. One chamber typically houses hydraulic fluid while the other contains inert gas such as nitrogen that’s typically under pressure.
As system pressure rises, nitrogen gas expands and forces hydraulic fluid into an accumulator. Once pressure drops again, this hydraulic fluid can be released back into the system when system pressure decreases again, providing power until both system and accumulator pressures equalize.
The size of an accumulator depends on its initial gas pressure, known as pre-charge pressure, which can be found from your supplier or determined via computer programs available from them.
Accumulators are commonly employed in systems where thermal expansion could cause excessive pressure, such as when there are blocked ports in an environment with high ambient heat and an expanding fluid is no place to go. Accumulators also come in low-pressure versions to keep airborne contaminants out of hydraulic oil reservoirs used by pumps; acting like breathing devices for their hydraulic oil levels as they rise and fall (For more circuits and information regarding accumulators see the author’s forthcoming e-book ‘Fluid Power Circuits Explained). (For more details see author’s forthcoming e-book “Fluid Power Circuits Explained.).
Energy Efficiency
As air is compressed through your compressor system, its energy increases as its pressure rises, only for it to drop again when the pump shuts off, creating a fluctuating air supply that may force your actuation system to look for flow elsewhere. An accumulator can absorb these pressure fluctuations to help even out your air supply and improve actuation system performance.
Your choice of an accumulator depends on your specific application. Two common types are gas-charged bladder and free-floating piston accumulators. With regard to bladders, two popular models include bottom repair style (most popular model is bottom repair style and new top repair style is available for easy replacement) or free floating piston type with seals between its chambers that separate gas from liquid; either of these options could prove more efficient depending on circumstances as they cost twice as much compared with their bladder-type counterparts.
Both types require regular inspection and maintenance to remain functional. If a desiccant becomes saturated with moisture, its ability to absorb it will wane, leading to its loss in pre-charge. In extreme circumstances, system pressure spikes exceeding an accumulator’s design capacity may crush its piston, while leakage or overflow could drain its liquid supply from an accumulator’s contents altogether.
An accumulator can be emptied using its dump valve and its current pre-charge can be monitored using a charging rig – providing insight into its performance in long term use and environmental conditions.
An accumulator’s main purpose is to store and recapture energy that would otherwise be lost, when system pressure increases it collects pressure fluid and stores it before releasing it back into the system when pressure drops, to reduce pressure peaks and power chassis suspensions. Furthermore, its energy can also help manage shock, vibration, and pulsations for added control – one reason many compressed air systems include both receiver/driers and accumulators/driers in their design.