Compressed air receivers are storage tanks that provide several benefits for your compressed air system.
Sizing of air receivers is not an exact science. There are several rules of thumb for sizing the tanks, and vary depending on control type and compressor size. Also, the air piping in the plant can serve as receiver capacity if it is large enough diameter. One rule of thumb calls for 1 gallon of receiver capacity for every CFM of compressor capacity. Another calls for 3 gallons of receiver capacity for every CFM of compressor capacity. Compressed Air and Gas Institute (CAGI) publishes charts based on compressor capacity and control method to select a receiver.
Receivers can be either “wet receiver” or “dry receiver”. This refers to the location of the receiver relative to the air dryer. The receiver placed before the air dryer in the line will be a wet receiver. It will accumulate the condensed moisture and must be diligently drained to prevent passage of water downstream. The receiver placed after the air dryer will generally be a dry receiver. If the dryer is refrigerated type or deliquescent type, it may still accumulate water and must be drained. If the dryer is a twin-tower regenerative type, there is little likelihood of moisture accumulating in the tank.
Receivers are pressure rated and considered by ASME as a pressure vessel. They must be provided with an adequately sized and rated pressure relief valve. This protects the air receiver and keeps it from over pressurizing. This also provides a measure of protection for the compressor as well as downstream piping and equipment.
In addition, a pressure gauge is recommended and usually supplied with the air receiver. As mentioned above, the accumulated moisture must be drained from the tank. The drain valve can be as simple as a manual ball valve which must be manually opened to drain. Other drain valve options are electric timed automatic drain valves, mechanical float-type drain valve, and more sophisticated zero air loss drain valves. The latter are energy saving devices that only allow water to escape, and prevent the compressed air from being wasted.
Pye-Barker Supply Co. sales engineers are experts in sizing and applications of air receivers and other compressed air products. We represent several manufacturers such as Steel Fab, Silvan, and others. Most common sizes are available from manufacturer’s stock.
When it comes to Air Operated Diaphragm Pumps (AOD) there are a lot of manufactures to choose from: Graco, Sandpiper, Wilden, Yamada and ARO to name a few.
All of these brands claim to be the best, and while they each have their advantages, when it comes to overall performance, the ARO air operated diaphragm pumps are the leader of the pack.
You see the purchase price of an AOD pump is the smallest piece of the cost-of-ownership pie. There are Downtime costs, Energy costs, Parts costs and Labor costs to consider as well. All of these costs add up over the life of the pump, making this a pretty sizable financial commitment.
That is why you should choose ARO for your AOD pump needs. ARO has the least overall total cost of ownership in the industry. With ARO AOD pumps you can slice the total cost-of-ownership down to a much more digestible size.
So what makes ARO pumps better?
a) Quick Dump Checks that eliminate downtime from pumps freezing up
b) Simulshift Valve / Unbalanced Air Valve that eliminates stalling out of the pump
c) Convoluted Diaphragms that get up to 4-times the life of traditional diaphragms
d) Engineered Thermoplastic Construction that extends pump life
e) Engineered Bolted Construction that creates a zero leakage, safer and cleaner environment
a) Positive Seal, Ceramic “D” Valve that creates zero energy wasted during pump idle
b) Quick Dump Checks and Simulshift Valves that create lower energy cost
a) Longer Lasting Wear Parts i.e. Convoluted diaphragms, easy access major air valve, simplified service kits that significantly reduce labor and parts cost.
b) Longer Lasting Wear Parts that help reduce the amount of spare parts needed on hand
All of the above examples help produce a pump that will significantly reduce the total-cost-of–ownership over the life of the pump.
ARO (EXP) Vs. Most “Advanced” Competitor
Test Subjects: 2” (Ports) Polypropylene Constructed Pumps with Teflon Diaphragms
Pump Operation: 8 Hours a Day/5 Days a Week/250 Days a Year = 2,000 Hours
Pump Delivery: 100 GPM @ 25 PSI (Back Pressure)
Energy Cost: $0.06 Per KW Hour
ARO (EXP) Air CFM Advantage: 37 @ 100 GPM
EXP Annual Cost Savings Per Pump: $618.93
Before you make your next AOD purchase, give Pye-Barker a call.
Purge air flow on an uncontrolled desiccant dryer is based on the nameplate rating, not the amount of compressed air flowing through the dryer. The purge flow is metered by an orifice or cracked open valve that takes a fixed flow of air from the tower that is regenerating. The cfm of air flowing thru the dryer does not change the purge flow unless there is a dew point or moisture control controlling the dryer.
Example: On a 1000 cfm fixed cycle dryer that is only running at of its rated or 500 cfm, the purge flow will still be 15% of the nameplate rating or 150 cfm, this would mean the real purge flow is 30% of flow.
Purge flows can change often, this is a manual adjustment that is done during a specific part of the dryer cycle, on most dyers the purge flow is controlled by a ball valve based on the pressure reading on a gauge, over time these valves can become misadjusted and purge exhaust ports can become plugged causing back pressure which changes the purge flow.
Dewpoint controls save energy by adjusting the dryer cycle time and purge time, letting the desiccant get fully saturated with moisture before the controls will let the dryer purge.
Southwire has two Gardner-Denver 250HP compressors rated at 1100 CFM each for a total of 2200 CFM, they have a 2700 CFM ZEKS desiccant dyer. The purge flow is 15% of rated flow or 405 CFM. When they have the dryer on-line and working correctly they are putting 2200 CFM into the dryer and the dyer is using 15% of that flow for purge air, so they are losing 405 CFM to purge flow which comes to about 18.5% of their compressor output. Instead of getting 2200 CFM like they need, they are getting 1795 CFM and that means when the dryer is on line the plant does get enough air to run.
International Paper, dealing with another distributor, replaced two Gardner-Denver 75HP compressors and a 650cfm refrigerated dryer with one 150HP Gardner-Denver compressor rated at 620 CFM and a 700cfm Airtek desiccant dryer. They found they could not run their plant because the dryer was using 15% of flow or 105cfm for purge flow; which meant they only had 515cfm of air flow. They had to buy an additional 200HP compressor to have enough air flow for the plant.
What dryer you use in your compressed air system can save energy and saving energy can lower your operating cost.
Let us help you make sure you have all the compressed air you plant needs.
Many customers when adding compressed air equipment or expanding production process with new compressed air system tend to work with plumbing or mechanical contractors with specification to stay with current black iron or copper piping and fittings. The installation of compressed air or vacuum pump equipment is typically part of the scope of purchase for pending plant upgrades or new projects.
The upfront costs of piping material and the compatibility with existing piping is normally primary concern versus the time and labor of installation.
Many compressed air manufacturers are now supplying new technology lightweight aluminum piping with quick connect fittings and elbows such as GARDNER DENVER's Quick-Lock Tubing. The structural integrity of the new aluminum piping or tubing meets current ASME standards and unlike black iron pipe, no pipe saddles or hangers are needed. The new aluminum tubing is supplied in standard lengths and cut on site easily for mounting with quick connect fittings. Black iron pipe installations may also require special lifting equipment due to weight of pipe and hangers required. This not required for lightweight aluminum.
The price difference for old school black iron pipe and fittings versus aluminum lightweight pipe and quick connect fittings is approximately 10 percent higher for the aluminum but where a normal installation of black iron pipe upgrade may take 3 to 4 days, the new aluminum lightweight piping is typically installed in one day; drastically reducing the downtime and labor for iron pipe install.
Some customers expressed concern over the availability of the new aluminum piping and fittings compared to iron, galvanized, or copper pipe. GARDNER DENVER keeps extensive inventory in local warehouse in North Carolina. Many local mechanical contractors are also keeping the new aluminum piping and fittings in their inventory.
One local customer who has seen the benefits of this new technology is International Paper in Lithonia GA. They upgraded their plant piping network with the new aluminum piping. Their current air system has three air compressors, one GARDNER DENVER RDS cycling type air dryer, and a 5000 gallon vertical air receiver. The time frame for complete piping installation was two days.
The technical specifications for the GARDNER DENVER Quick-Lock aluminum tubing (reference documents GA-QLT-100 or GA-BLT-100) show maximum pressure of 220 psig and maximum temperature of 176 deg F. The maximum pressure for vacuum pump installations is 29.6 inches hg V. These ratings meet most ASME compressed air or vacuum system requirements.