2 Contents • ALMiG refrigeration dryers • Why use dry compressed air? • What is refrigeration drying? • Refrigeration dryer function • Overview of ALM refrigeration dryers • ALM refrigeration dryers • ALM 25 – 110 • ALM 150 – 1100 • ALM 1320 – 2150 • ALM 2400 – 5300 • Advantages of „energy-saving-speed controlled version“ ALM -E • Refrigeration dryer design
Average water content of air 14 12 10 g/m³ 8 6 4 2 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Why use dry compressed air? • Untreated compressed air • results in increasing leakage of the pipe system • affects highly compressed air applications (e.g. pneumatic tools) • results in - high maintenance costs • - long production downtimes • - serious quality issues in the production process Compressed air pipe Pneumatic tool
The ability of compressed air to absorb water vapour depends solely on temperature and not operating pressure.
Classification of moisture reg. DIN ISO 8573-1:2010 Area forrefrigerantdryers
Maindrying procedures Adsorption Condensation Refrigeration dryer(PDP ≥ +3°C) Adsorption dryer(PDP < 3°C to -70°C)
What is refrigeration drying? Refrigeration drying is a process in which the compressed air is cooled by a refrigerant in a heat exchanger. This condenses the water vapour in the compressed air and separates it out. The greater the difference between inlet and outlet compressed air temperature, the greater the amount of water condensed. The lower the compressed air's cooling temperature, the less moisture remaining. Drying comprises two phases: First phase: The warm compressed air enters an air / air heat exchanger in the opposite direction to the compressed air already cooled and exiting the unit. No extra energy is required for this process. Around 70 percent of the water vapour is removed as condensate. Second phase: The compressed air flows through an air / refrigerant heat exchanger and cools to the specified pressure dew point (e.g. 3°C). The remaining moisture condenses before this point is reached, is removed and discharged through a condensate drain.
Refrigeration dryer function Route travelled by the compressed air Precooling of the fully saturated, warmcompressed air in the air/air heat exchanger 1 1 4 Cooling to the pressure dew point in the refrigerant / air heat exchanger 2 2 Condensate collected is discharged by the separator / drain 3 The dry compressed air exiting the unit is heated by the compressed air entering in the opposite direction 4 Compressed air approx. +3 to +5°C 3 ! No condensate produced in compressed air network unless the compressed air temperature falls below +3° to +5°C!! Reduction in moisture to ISO class 4, PDP: ≥ + 3°C
Overview of ALM type ALMiG refrigeration dryers ALM 25 – ALM 110 5 models from 20 to 100 m³/h ALM 150 – ALM 1100 10 models from 140 to 1000 m³/h ALM 1320 – ALM 2150 4 models from 1200 to 2000 m³/h “E” version with energy-saving-speed control ALM 2400 – ALM 5300 6 models from 2200 to 5100 m³/h “E” version with energy-saving-speed control Larger types and special options on request !
With static condenser ALM 25 – 110 On/Off switch Dew point indicator Integrated time-controlled condensate drain (standard) * = inlet temperature 35°C; operating pressure 7 bar; pressure dew point +3°C
Benefits of ALM 25 - 110: • Static condenser (refrigerator principle): • No fan required; • quiet, • fewer wearing parts, • no air turbulence, • no dust • No influence from ambient temperature up to 45°C • Time-controlled condensate drainage • Warm outlet air (T-outlet = T-inlet + 5°C) thanks to exchange of relative heat • Easy to install: connect piping, plug in power cable , job done! • Integrated demister separator (function: metal wool "captures" and collects water droplets from damp air) • Long service life through use of quality components • Using the heat produced by condensation means that there are no cold, damp pipes at the air outlet
A-Drain: standard, electronically controlled condensate drain ALM 150 – 1100 * = inlet temperature 35°C; operating pressure 7 bar; pressure dew point +3°C
Vorteile ALM 150 - 1100 • Crossflowstainlesssteelplate-type heatexchanger (coppersoldered) • Ensuresoptimumheatexchangeandpreventscondensation on coldpipes • Newlydevelopedconstantpressurevalve • Constant refrigerantsupply • Constant vaporiseranddewpointtemperature • High-quality coolingcompressors • Aboveaveragecoolingrating • Piping not pronetovibration • Vibrationsandoscillationsare not transferredtoconnectionpoints -> noleaks • Electronicallylevel-controlledcondensatedrain • Automaticallydischargesthecondensatecollected • Nocompressedairlosses • Connections madeofstainlesssteel • Totallycorrosionfreesystem • Housingdesignedfor easy maintenance A-DRAIN Electronically level-controlled condensate drain Crossflow stainless steel heat exchanger
Other benefits of ALM 150 - 1100: • Compressed air inlet temperatures up to 55°C • Ambient temperatures up to 45°C • Maximum operating pressure of 16 bar(g) (higher pressures on request) • Very low pressure losses • Air / air heat exchanger with high effectiveness caused by small energy consumption • Easy to install: connect piping, plug in power cable, job done! • LED dew point indicator on control panel (ALM 350 and higher) • Long service life through use of quality components • As a safety pressure limiter, the constant pressure valve (CPV) provides an overload shutdown mechanism: • If the coolant temperature increases, the cooling medium pressure increases too the dryer shuts down and an alarm is issued. This ensures that the dryer is not damaged.
ALM 1320 – 2150 * = inlet temperature 35°C; operating pressure 7 bar; pressure dew point +3°C
Benefits of ALM 1320 - 2150: • Space-saving installation thanks to narrow, vertical design • Low power consumption • Heat exchanger version optimised for compressed air applications: • Sinusoidal, large, smooth air ducts • Low pressure loss through dryer • Outstanding accessibility for service as sheet metal panels can be removed on all four sides • Robust, reliable refrigeration control (HGBV: hot gas bypass valve) • Use of R134a or R404A refrigerants, typically used by industry • Temperature displays for compressed air inlet, compressed air outlet and dew point
ALM 2400 – 5300 * = inlet temperature 35°C; operating pressure 7 bar; pressure dew point +3°C ** = energy management
Benefitsof ALM 2400 - 5300: • Plate-type stainlesssteelheatexchanger, coppersoldered • Heatexchangerversionoptimisedforcompressedairapplication: • Sinusoidal, large, smooth airducts • Low drop in pressurethroughdryer • Useof R404A refrigerantasstandard • Low installationcost; easy tomaintainaspanelscanberemoved • High reliability, efficiencyanddurability • Dryerscanbepositionedwithonesidefacingthe wall, whichreducestheinstallationarearequired • Coldairoutput: noneedfor an air/airheatexchanger on theoutputsideifverycoldcompressedairisrequired. • Filter separatorand/orcoalescencefilter Digital Scroll(Otion) Demister separator Very fine oil filtration in cold air flow • Energy saving from use of Digital Scroll: If the dryer runs without load, the scroll wheels move apart thereby reducing internal resistance. Energy saving compared with standard refrigeration dryers: up to 80% !!
Overview of ALMiG-Energy-Saving-Drier“ type ALM E ALM 1320 – ALM 2150 4 models from 1200 to 2000 m³/h “E” version with energy-saving-speed control ALM 2400 – ALM 5300 6 models from 2200 to 5100 m³/h “E” version with energy-saving-speed control
Energy-Saving-Drier ALM 1320 – 5400 E: ALM E: Constructive difference to the ALM series • ReplacementoftheDanfoss "standardcoolingunit" with a Danfoss high efficiency "speed-controlledcoolingunit" and a "Danfossfrequencyconverter" that also hastobefitted • In technicalterms, thismeans: • minor design changesresultingfromsimplyreplacingthecoolingunitusing a "plug’nplay" system. • all othercomponentsareidentical.
Energy-Saving-Drier ALM 1320 – 5400 E: • Note: • ALM – E has: • same max. volume flow • same pressure dew point • same pressure losses • same dimensions • lower power consumption • The power consumption depending on the utilisation (30 - 100%) consists of 3 factors:: • Savings due to intelligent energy‐saving speed control • Savings by reducing the amount of heat sucked into the energy‐saving refrigeration dryer based on Summer time and Winter time (warm/cold) • Savings by reducing the amount of heat sucked into the energy‐saving refrigeration dryer based on • a lower outlet compressed air temperature in normal operations, for speed‐controlled compressors.
Refrigeration driers can work in very different ways, for example: Refrigeration dryer with energy-saving control • Standard refrigerationdryers • In the case of standard refrigerant driers the current consumption is always 100%. • no matter whether the compressed air throughput through the refrigeration dryer is at 100%, varies, or is zero • once it is switched on, the refrigeration dryer always uses 100% energy • a standard refrigeration dryer causes unnecessary energy costs • In the case of these refrigeration dryers an intelligent energy-saving speed control ensures that the electrical power consumption always rises or falls almost proportionally to the compressed air throughput • The electrical power consumption is always at the optimum level, in energy terms • Unnecessary energy costs are avoided • If the compressed air production goes into stand-by or is switched off: • the energy-saving dryer also goes into stand-by operation • the electricity uptake is reduced to a minimum • Important: • The refrigeration dryer is not completely switched off, but is permanently ready for use but with reduced electricity uptake • A constant low pressure dew point is guaranteed, even if the compressor goes into operation for a short time
Field of applications for „energy-saving-speed control“ drier? • Productionofcompressedairusing a speed-controlledcompressor, refrigerationdryerinstalledbeforecompressedairreceiver • The compressed air generated by the variable speed compressor varies depending on the air requirement • „Energy-saving-drier“ adjusts its power requirement to the air output • „Standard drier“ operateswith 100% power consumption. • Compressor is turned off or in standby (no FAD) • „Energy-saving-drier“ is in stand-by, energyconsumptionreducedto a minimum, readytooperate • „Standard drier“ operateswith 100% power consumptionevenifnoairispassingthroughthedrier
Field of applications for „energy-saving-speed control“ drier? 2.) Productionofcompressedairusing a fixedspeedcompressor, refrigerationdryerinstalledbeforecompressedairreceiver • Constant FAD (100%) fromthecompressor • „Energy-saving-drier“ operatswith 100% power consumption • „Standard drier“ operateswith 100% power consumption • Compressor is turned off or in standby (no FAD) • „Energy-saving-drier“ is in stand-by, energyconsumptionreducedto a minimum, readytooperate • „Standard drier“ operateswith 100% power consumptionevenifnoairispassingthroughthedrier
Field of applications for „energy-saving-speed control“ drier? 3.) Productionofcompressedairusing a fixedspeedorspeedcontrolledcompressor, refrigerationdryerinstalledafter compressedairreceiver • The FAD generated by the compressor passes into the compressed air tank. In response to the compressed air demand the FAD after the tank varies. • „Energy-saving-drier“ adjusts its power requirement to the air output • „Standard drier“operateswith 100% power consumption • Compressor is turned off or in standby (no FAD) • „Energy-saving-drier“ is in stand-by, energyconsumptionreducedto a minimum, readytooperate • „Standard drier“ operateswith 100% power consumptionevenifnoairispassingthroughthedrier
Calculation of the energy saving potential Example: ALM 1320 vs ALM 1320 "E" Energy price: € 0.15/kWh Working hours compressor station: 4000 Drier utilisation: 70%
Calculation of the energy saving potential Example: ALM 5300 vs ALM 5300"E" Energy price: € 0.15/kWh Working hours compressor station: 4000 Drier utilisation: 70%
Market overview „Energy saving dryer“ In addition to the energy saving dryers with "Speed control“ the market offers also energy-saving dryer with "Cold accumulator”. Function description according to manufacturer: The cold accumulator with high specific capacity is cooled by the refrigerant circuit and extracts the compressed air heat. If necessary, the coolant compressor cools down the accumulator again. Note ALMiG: Very often normal sand is used as „cold accumulator“ Cooling compressor on, cools compressed air + 'cooling reservoir' Pressure dew point falls 1 2 3 Cooling compressor off. Cooling of compressed air depends solely on cooling reservoir Pressure dew point rises Result: More moisture in the compressed air network • If more compressed air is needed suddenly when the cooling compressor is off (see point A), the system oscillates in response. • Pressure dew point rises very fast; the system is too slow to absorb these fluctuations! • Result: Much more moisture in the compressed air network ALMiG measurement protocol of a "refrigerated dryer with cold accumulator
or Installation upstream or downstream of receiver? Installation upstream of receiver Installation downstream of receiver + Dryer is always subject to constant volume flow by compressor (dryer is not "bypassed"). - In the event of high consumption, the refrigeration dryer can be "bypassed" – especially if there are a only few, but large compressed air consumers. + No condensate is collected in the compressed air receiver Receiver remains dry. - Condensate collects in the receiver Inner walls must be protected from rust. - High compressed air inlet temperature because short cooling section (install larger dryer if required). + Compressed air cooling up to dryer inlet (smaller dryer available if required).
Refrigeration dryer design • The ALMiG refrigeration dryer design is based on: • the compressed air inlet temperature in the refrigeration dryer the higher the inlet temperature, the lower the throughput • the ambient temperature at the dryer installation site the higher the ambient temperature, the lower the throughput • the operating pressure of the compressed air the higher the operating pressure, the greater the throughput • In accordance with DIN ISO 7183, as a rule, all standard refrigeration dryer details relate to • compressed air inlet temperature of +35°C • ambient temperature of +25°C • operating pressure of 7bar
Example of dryer design: • Specified parameters • Volume flow: 725 m3/h • Pressure dew point: +3℃ • Compressed air inlet temperature: 40°C • Ambient temperature: 30℃ • Operating pressure: 11bar • Design • Advance dryer selection: ALM 900 where V=689 m3/h • Volume flow correction: Vcorr= V x ftu x fpu 689 x 0.94 x 1.13 =732 m3/h • ALM 900 fits the bill !! (with a reserve !)
Example of dryer design: The „game“ with parameters: If the pressure dew point is not decisive and can be set on +10°C, the calculation will be as follows: • Specified parameters • Volume flow: 725 m3/h • PDP: +10°C • Compressed air inlet temp.: 40°C • Ambient temperature: 30°C • Operating pressure: 11bar • Design • Advance dryer selection: ALM 740 where V=685 m3/h • Volume flow correction: Vcorr= V x ftu x fpu 685 x 0,94 x 1,13 =728 m3/h • ALM 740 fits !! Result: If temperatures inside the pipe system never fall below +10°C, there will be no condensate, and customer may choose a smaller dryer type..
Example of dryer design: Comparison pressure losses ∆P for ALM 740: 0,23 bar ∆P for ALM 900: 0,16 bar Difference in price: ALM 900 : ALM 740 ca. 15% Result: Customer may choose, if he prefers a smaller pressure loss or a lower price for the dryer.
ALMiG Kompressoren GmbH Adolf-Ehmann-Strasse 2 • 73257 Köngen Sales tel. no.: +49 (0)7024 9614-240 Sales e-mail address: firstname.lastname@example.org www.almig.de