Elevation, atmospheric pressure, and baking
The pressure level of atmosphere at any specific point on earth is relative to the altitude of that position. Understanding what the atmospheric pressure is at your specific location is important to better understand how your vacuum pump will operate.
If you have ever tried to bake a cake from a premade mix you may have noticed that there were different instructions for those who live at high elevation. At higher elevation the atmospheric pressure is lower. Lower pressures speed along evaporation and expansion, and so in our baking example, at higher elevation means recipes have to cook for shorter amounts of time, less leaveners are added, and often more moisture must be added in order to get a similar end product to a recipe made at sea level.
As altitude increases, pressure decreases. After crossing over under atmospheric pressure you start to measure in negative pressure, or vacuum. If you have ever traveled in your car from lower to higher elevation with a bag of unopened chips you may have noticed by the time you are at the top of the mountain the bag looks like it is about to explode. This is another example of how decreased pressure at higher elevations allows for molecules to expand.
At Provac Sales, Inc. we are lucky to live close to the ocean. At main warehouse the elevation is close to sea level. Our atmospheric pressure is 760 Torr. In contrast Denver Colorado is located at 5,280 feet above sea level and their atmospheric pressure is approximately 630 Torr. If you are starting a vacuum pump at higher elevation in Denver from atmosphere it would get a 100 Torr “head start” over one which had to start at lower elevations.
In our baking example, increased elevation reduces pressure and reduces bake time. Manufactures can mimic the advantages of higher elevation by using vacuum pumps in their production process. Processes such as vacuum baking and freeze drying utilize a vacuum pump to remove molecules from baking or drying environment. With the absence of more molecules, manufactures can reduce bake/dry times at reduced temperatures, which helps to preserve the product and speed along manufacturing.
Single stage oil sealed vane pumps, oil sealed piston, dry screw pumps are popular choices for food manufacturing industries as they can tolerate pumping down from atmosphere, and higher levels of moisture which is a common biproduct.
Provac Sales, Inc. offers new and refurbished vacuum pumps for your vacuum baking, food processing, and freeze drying applications. Contact us today for a quotation.