Boyles Law: The pressure exerted by a given mass of an ideal gas is inversely proportional to the volume it occupies, at constant temperature.Ideal Gas Law: In a perfect or ideal gas the change in density is directly related to the change of both temperature and pressure.The continuum theory is what we call macroscopic in nature, and governed by the gas laws such as The Ideal Gas Law, Boyles Law, and Daltons Law. In simple terms, it tells us that collisions between gas molecules dictate the properties of a gas. The Continuum Theory and The Kinetic Theory of GasesĪt or near atmospheric pressure, and in non-vacuum systems, the so-called continuum theory accurately describes the properties of gases. At these extremely low pressures, the collisions between molecules, which normally dictate the properties of gases, become very infrequent and a different theoretical model is required to explain their properties (the so-called Kinetic Theory of Gases). To put it into proportion, if gas molecules were grains of sand, at ultra-high vacuum they would be 1,650 meters apart. Since the diameter of each gas molecule is much less than this (4 x 10 -8 cm for air, for example), there is a great deal of space between molecules.
![solidworks 2005 check for collisions interference solidworks 2005 check for collisions interference](http://slideplayer.com/slide/14174912/86/images/6/Careers+in+SolidWorks+Number+of+Job+Postings+on+Monster.com+on+October+1%2C.jpg)
At this density, there is only one molecule roughly every 0.33 mm in space. Under lower and lower pressure, the molecules spread out further and further, until, at ultra-high vacuum (10 -12 mbar), there are only 2.65 x 104 or 26,500 molecules per cubic centimeter. There are roughly 2.65 x 10 19 or 26,500,000,000,000,000,000 molecules in a cubic centimeter of gas at 10 3 mbar, which is atmospheric pressure at sea level (Table 2). If we take this same 1 cubic meter volume of gas and increase its volume sufficiently for the pressure to be reduced to 10 -12 mbar (ultra-high vacuum), the container will be a staggering 99 km long x 99 km wide x 99 km high, or 200 times the volume of the grand canyon! Figure 1 | The Grand Canyon National Park 1Īnother way to understand the operating pressure range of industrial vacuum systems is to consider gas density or the number of gas molecules that reside in a given volume. When this relationship is expanded to the scale of industrial vacuum systems, the result is striking. If, for example, the container volume is doubled to 2 cubic meters, the pressure will decrease by half, to 500 mbar.
![solidworks 2005 check for collisions interference solidworks 2005 check for collisions interference](https://hawkridgesys.com/media/amasty/blog/cache/i/n/1200/675/interference-range-motion-solidworks-blog-0.jpeg)
It is easy to understand that if the container is expanded in volume while still remaining sealed, the pressure will decrease (and a vacuum will be created) in direct proportion to the increase in volume (in accordance with Boyle’s law). Consider a volume of gas at a pressure of 1000 mbar (atmospheric pressure) in a 1 meter by 1 meter by 1 meter container sealed so that no molecules can escape or enter. In fact, the range is so large it is hard to actually comprehend. Table 1 –|Typical pressure ranges of industrial vacuum systems Table 2 | Density of gas (molecules per cm3) for various pressure rangesĪs shown by the difference in pressure from low to ultra-high vacuum, industrial vacuum systems must operate under an extremely wide range of pressure. These ranges are very useful in describing the various pressure, flow, and other phenomenon encountered, which leads to a better understanding of vacuum pump selection and operation, and system operational requirements at the different vacuum levels.
![solidworks 2005 check for collisions interference solidworks 2005 check for collisions interference](https://docplayer.net/docs-images/42/3657910/images/page_10.jpg)
#Solidworks 2005 check for collisions interference series
In this series of articles, we will review the first principles of vacuum technology and explain them using real-world illustrations. Most industrial vacuum systems can, in broad-based terms, be categorized in terms of low (i.e., “soft”), medium, high (i.e., “hard”) and ultra-high vacuum (Table 1). As in any discipline, understanding the underlying scientific principles has profound practical implications when properly understood.