Tag: reciprocating

Double Dare, Double Dragon, Double Mint Gum

Published on by Brian FarnoLeave a comment
1 -Classic Double Dragon Arcade Game from 1987! Spike & Hammer Save The World – This is the game I used to dump quarters in every visit to the mall.

It’s no secret, I’m a kid of the 80s. If you remember any of the three items in the title of this blog, then we may be able to be friends still, and I want to ask a question. How’s your sourdough starter doing? Okay, you got me, the blog isn’t going to be about sourdough, or one of my favorite TV shows from growing up, or the video game I always threw quarters into when we were allowed to spend some money at an arcade, but it’s going to be about Double Acting Reciprocating Air Compressors.

You may have heard from us about the many types of compressors before, and we would just like to make sure we have shared a few different viewpoints on these topics. The double acting compressor is a piston action compressor. Unlike the single action compressor, these will actually build pressure above and below the piston for each rise and fall, rather than just the rise. Because this generates twice as much air, these are generally found in larger sizes than the single acting compressors. This also means the compressor is constantly pushing a load out of the system whenever the motor is turning. While they do put more volume out and work with both directions of the piston, they have been found to only be around 32% more efficient than their single acting counterpart. Nonetheless, they are available in sizes that can supply an entire manufacturing facility and can be used efficiently when placed into a system that is designed correctly.

If you want to learn about more types of compressors, need help with your Konami cheat code, or what to discuss a point of use compressed air application, give us a call, chat, or email.

Brian Farno, MBA – CCASS Application Engineer

BrianFarno@EXAIR.com
@EXAIR_BF

1 – Classic Double Dragon Arcade Game from 1987! Spike & Hammer Save The World – Joe’s Classic Video Games – retrieved from – https://www.youtube.com/watch?v=_SqYOHpUiDM

Five Things To Know About Single Acting Reciprocating Compressors

Published on by Russ BowmanLeave a comment

With the development of highly efficient air compressors, there’s still a place for the most basic design: the single acting reciprocating compressor.  When the piston moves out of the cylinder, it draws air in, at atmospheric pressure.  When it moves in to the cylinder, it reduces the volume that air occupies, increasing its pressure.  These machines are durable, effective, relatively inexpensive, and pretty easy to maintain.  Here are a few interesting things to know about them:

1. Popularity. Because of the simplicity of their design, they’re the most common air compressor in the 10HP and under sizes.  You can get them from a number of sources, and they’re not going to set you back as much as some other types.
2. Oil free air (part 1) While the most basic design uses oil to lubricate the piston rings in the compression cylinder, oil-less reciprocating compressors have cylinders with very smooth (and hard) bore surfaces, like nickel or chrome plating. A series of guide rings around the whole circumference of the piston prevent metal-to-metal contact, eliminating the need for liquid lubrication in the compression cylinder.
3. Oil free air (part 2) If oil in your compressed air is a problem, an oil-free (as opposed to oil-less) compressor is another option. While an oil-less compressor doesn’t use lubricant for the piston movement, an oil-free compressor’s moving parts are oil lubricated, but that oil is kept away from the compression cylinder(s) with connecting rod(s) so that the oil is confined to the lower moving parts…the crankshaft and bottom ends of the connecting rods, and away from the pistons & compression cylinders.
4. Foundation. Reciprocating machinery, as the name implies, has parts that move back and forth. The sudden reversal of direction of heavy metal pistons & rods, dozens of times a minute, means that their operation is inherently unbalanced. This out-of-balance condition, though, can be absorbed by properly securing the compressor to a properly prepared foundation.
5. Higher pressures. If your facility’s compressed air usage primarily entails pneumatic tools, cylinders, and blow off devices like air guns, the system header pressure is likely maintained at around 100psig. While a one-stage reciprocating compressor is usually rated for discharge pressures up to 125psig, a second stage can increase that to 175psig. Multi-stage compressors are used for applications that require up to 3,000psig compressed air. Examples of these are scuba breathing air, pneumatic excavators, and my personal favorite: ballast tank blowing air, used to surface a submarine.

4-stage reciprocating compressors charge 3,000psig air tanks that are used to rapidly push water from a submarine’s ballast tanks to create positive buoyancy.  Because keeping your ‘diving-to-surfacing’ ratio at 1:1 is important.

At EXAIR Corporation, helping you get the most out of your compressed air system is important to us.  If you’ve got questions about how to do just that, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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About Dual Acting Reciprocating Compressors

Published on by Brian FarnoLeave a comment

When it comes to generating compressed air there are many types of compressors to utilize within a facility.  One of those types is a dual acting reciprocating compressor.  This is a type of positive displacement compressor that takes advantage of a piston style action and actually compresses air on both directions of the stroke.  Below you can see a video from a company that showcases how a dual acting compressor works and gives a good representation of how it is compressing the air on both directions of travel.

Dual_Recip
Click on this image for video

The reciprocating type of air compressor uses a motor that turns a crank which pushes a piston inside a cylinder; like the engine in your car.  In a basic cycle, an intake valve opens to allow the ambient air into the cylinder, the gas gets trapped, and once it is compressed by the piston, the exhaust valve opens to discharge the compressed volume into a tank.  This method of compression happens for both the single and double acting reciprocating compressors.

With a single acting compressor, the air is compressed only on the up-stroke of the piston inside the cylinder.  The double acting compressor compresses the air on both the up-stroke and the down-stroke of the piston, doubling the capacity of a given cylinder size.  This “double” compression cycle is what makes this type of air compressor very efficient.  A single acting compressor will have an operating efficiency between 100 cfm / 23 kW of air while the double acting compressor has an operating efficiency between 100 cfm 15.5 kW .  Therefore, electricity cost is less with a double-acting reciprocating air compressor to make the same amount of compressed air.

These compressors are ruggedly designed to be driven 100% of the time and to essentially be a Clydesdale of compressors.  They are commonly used with applications or systems requiring higher pressures and come in lubricated or non-lubricated models.

If you would like to discuss air compressors or how to efficiently utilize the air that your system is producing so that you aren’t giving your compressor an artificial load that isn’t needed, contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF