Today we will know más on a very important system in airplanes, we will talk about the pressurizationón that offers safety and comfort to travelers.
We have previously reviewed in this blog important issues about pressurizationón and the air we breathe in the planes, But this time we will have another visionón of this fundamental system in thousands of flights and airplanes in the world.
Post written by: William Casalins
Aeron Engineeráuseful
Foundationón SON
Our Friend The Pressurizationón
The pressurization is well knownÓN in the largestíA of the passengers and of course among the crew and mecánicos of aviationón. Is indeed what insinúTo the word pressurize (presión). People immediately think of oxígeno, knows that as the air rises it is less dense and concentrationón of this is decreased with the height, Until it is PRáCutically insufficient for the vital requirements of the human being and even for the greateríA of animals, that's true, But it is only part of what really happens in the Avi cabinsón when we venture to be in places for which we are not made and that are extremely hostile for life.
The air we breathe isá composed of several types of gases and is oxígeno, what, although it isá in a lower percentage (más the least 20%) is the Más necessary for life; But it is úTil as long as it can be properly assimilated and in sufficient amounts by the alveoli of the lungs and be distributed by the blood to the whole body.
The flight attendants in the instructions tell us, very smiling, what, in case of depressurizationón, fallán the respective máox scarasíGeno and that we put ours before helping someone who needs it, But they know that the M is going to be lowered to lower levelsás ráI ask for possible, Whats that for, ¿If we have the máScaras put? That is a good question.
The answer is the same for which astronauts or great depth divers need not only oxíGeno but special costumes.
As we ascend we know that the presión decreases and that partiesíox cellsígeno isán más scarce (by volume) and when pressurizing (Increase presión in the cabin) again concentrateíAn in adequate proportions for human consumption; But it turns out that if Eastá very high, depending on each person, Even if you have a máOx scaleíGeno supplying enough air, At those flight levels your lungs not to beíAn capable of absorbing enough oxíGeno to keep you alive, It is necessary to go down for the body to beé In a less hard environment and Más friendly for life (as we know it). Transportation toéRegular passenger inmate implies being able to bring to the greatest number of people from one place to another without these being athletesímpicos (or ordinary people) And that is why we must simulate the Máan atmosphere where the greatestíWe feel at ease and without the fear of suffering all the diseases that implies being for prolonged times in necessary flight heights (operationally) today díA in the navigationón aérea.
Now something M is comingáInteresting ¿thaté marketíto if we rise más y más, like the passengers of a Concorde, un SR 71 or a high-altitude balloon? marketán unsuspected things. Water, at sea level with a pressureón máS the least of 29.92 inches of mercury or 14 psi (pounds per square inch) boils to 100 degrees centídegrees, as we rise it boils at a lower temperature, in Bogotaá for example would be around 92 degrees centídegrees, a 8848 meters (Everest) a 86 degrees to 11000 (at normal flight height) a 71 degrees and 19000 meters to 37 degrees. That doesn't haveíto greater importance if our body was not in its greatestíA water and if our temperature was not MáS the least 37 degrees centídegrees, because that means that 19000 meters (60000 pies, almost normal flight level in a concorde) Our blood beía, If it weren't for your pressureón internal, about to boil, with the serious consequences that this entails for our health, we roast in our juice, literally, because saliva if it could boil.
Known all this we can understand the great efforts made by engineersñendors and aircraft construction companies to fly to higher levels, or you are very tall, it brings many benefits to the flight, Avoid congestión of airplanes, normalme isán about bad weather, engines consume less fuel and in some areas they take advantage of favorable winds (jet stream)although the pressurizationón indicative más weight, más Fuel consumption, más costs in your constructionóN and Más systems to operate; además to have to control the temperature with sophisticated air conditioners that are so complicated and AntieconóMycos that modern aircraft recycle part of that air through efficient filters inside the system, not to mention the drag that is generated to cool the air conditioning heat exchangers.
Now let's see CóThey do it, the first is a cabin fully sealed and reinforced for the pressures and cycles it must withstand, the second is to get an air source, nowadays, with turbine engines, It is very fáCIL obtain it from the early stages of the compressor, a pressure control systemón that is normally achieved by controlling the VáLvule where the air comes out ,Yes enter más that the one who is pressurizing, you go up más of the one who enters spoke ,If the same volume comes out from the pressureón inside the cabin is maintained and obtained automallyáethics, semiautomáethical and manual. Lógically some V systemsáSecurity LVULES To avoid that in the case of a failure of the controllers or human the integrity of the collapse structure by overpreprepóOn the contrary for a presión exterior than to doíto make the cabin implosión.
THE HISTORY OF PRESSUREón, Like almost all aeron innovationsáUticas, it has its dark and painful side, the various accidents of the De Havilland Comets, Due to structural failures due to pressurization cyclesón and despressurizationón, These disasters contributed a lot to the development of the industry in the development of the new CéLULAS AND DESIGNñor of the windows of the modern jets that we fly today.
This was one of the topics that argueíA followed with a great aviator, Friend and CompañBut the Capán Alvaro Mejia on long flights where his experiences told me, those that enrichíto the knowledge and importance of a good and correct operationóteam no., But the torches go from a generationón to another and now I make those discussions with a young and studious commander Cristian Cuesta, that when he arrives at the cruise he takes out his notes, adjust your chair, Look to ATRás and ask house…?
Note: The comet was not the first avióN Passenger Pressure, nor the first to have square windows, But due to its impressive accidents it is what más has left teachingñANZAS FOR FUTURE DESIGNños.
