- #Airflow system dustcrawler compressed air usage how to#
- #Airflow system dustcrawler compressed air usage full#
- #Airflow system dustcrawler compressed air usage professional#
What is the Cost of Over-Pressurizing the System?Īn industry term that has been used in recent years to describe supplying more pressure to the system than is necessary is “artificial demand.” For example, if the production floor only needs 75 psig to maintain steady production, why maintain the compressed air header at 100 psig? The artificial demand in this case is 25 psig. In this simple example, I would recommend adding a 7.5-hp compressor to the system to add volume, which will stabilize the discharge pressure to the desired level.
#Airflow system dustcrawler compressed air usage how to#
Let’s take a look at an example of how to use Boyle’s Law in a real-world scenario: Where P1 is the initial pressure, V1 is the initial volume, P2 is the final pressure, and V2 is the final volume. What is the Relationship Between Flow and Pressure?Īnother little known fact about compressed air from an end user’s point of view is that discharge pressure has a direct impact on flow. Why you ask? Because production workers typically blow off their workstations between shift changes.
#Airflow system dustcrawler compressed air usage full#
A comical fact when conducting a full plant air audit (both supply side and demand side) is that in many cases the largest event that spikes the system is a shift change.
it will follow the path of least resistance). Remember, compressed air is “stupid” (i.e. A handy rule of thumb to remember is that a 1/4-inch opening/orifice will leak approximately 100 cfm at 100 psig. Therefore, out of these two relatively small leaks, the 200-hp compressor was losing essentially one tenth of its overall capacity. The moral to the story is that the quarry worker didn’t know that by opening two 1/8-inch valves under 100 psig discharge pressure the system would lose approximately 100 cfm, which equates to a 25-hp rotary screw air compressor (rule of thumb is that a rotary screw compressor delivers 4 to 5 cfm per 1 hp). When we arrived back at the compressor, the machine was at full pressure. I instructed the owner to have those two valves closed. After several minutes of investigation I found the culprit, a quarry worker had opened two 1/8-inch ball valves to direct some of the compressed air on his face in an effort to cool himself in this sweltering environment. I knew that this had to be a “system” problem and not a “compressor” problem, so I began to walk around the quarry to see what I could find. However, as the day got hotter I witnessed just what the owner had said - the discharge pressure began to fall. I arrived early the next morning, and the compressor setting was at 115 psig discharge pressure, just where it was supposed to be. I also knew that the only way for me to solve this phenomenon was to visit the site to gather data. Being a degreed engineer, I knew that what he was describing wasn’t possible. As you can imagine, this is a hot environment for the employee who is working the torch.Ī couple of weeks after the compressor was installed, I received a call from the owner, who was complaining that the compressor wouldn’t hold the desired pressure as the ambient temperature increased throughout the day. An air compressor is needed in this process to project the flame. This process is performed many times vertically down several hundred feet beneath the ground. One way granite is mined is by using a high-temperature torch that melts the rock to enable a slab to be removed. After thoroughly reviewing a compressed air system, I sold a 200-hp rotary screw compressor to a granite mining facility in east Georgia. I remember an experience that occurred many years ago when I worked for a major U.S. In this article, I try to address the subject in a way that non-engineering types can understand. There have been many articles written on this subject over the years, but many of them have been so technical that it was difficult to follow for a person outside of the industry. Furthermore, the majority of production personnel do not have a clue that compressed air isn’t free.
#Airflow system dustcrawler compressed air usage professional#
Walk into many body shops or small manufacturing plants, and you will find the compressor operating at an elevated pressure to satisfy the “demand.” If a plant has low air pressure on the production floor, what is the first thing that the maintenance professional does? You guessed it: He or she “jacks” up the pressure on the compressor, not realizing that he or she made the problem worse. After more than 25 years in the compressed air industry, it still amazes me that many plant personnel and even those who sell compressed air products for a living don’t fully understand the relationship between flow, or volume (cfm), and pressure (psig).
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