It is denoted by Twb.ħ Relative humidity: it is defined as the ratio of partial pressure of water vapour in a mixture to the saturation pressure of water at dry bulb temperature. Wet bulb temperature: it is the temperature indicated by a wet bulb thermometer which has its temperature sensitive element (bulb) covered with a wick soaked in water. Dry bulb temperature: it is the equilibrium temperature of the mixture indicated by an ordinary thermometer denoted by Tdb. Denoted by ‘ω’.ĥ Dalton’s law of partial pressures: the total pressure of the mixture of gases is the sum of the partial pressures exerted by each gas when it occupies the same volume of the mixture at the same temperature of the mixture. This temperature at which condensation of the vapour begins resulting in formation of liquid droplets or dew when the mixture is cooled is called dew point temperature.Ĥ Absolute humidity or specific humidity or humidity ratio: The ratio of mass of vapour to the mass of dry air is called absolute humidity. Dew point temperature: when the unsaturated air is cooled at constant pressure, the mixture reaches saturation temperature corresponding to the partial pressure of water vapour.
Super saturated air mixture: it is a mixture of dry air and water vapour in which the partial pressure of the water vapour is greater than the saturation pressure of water at the temperature of the mixture. The partial pressure of vapour being less than the saturation pressure of water at the temperature of the mixture. Saturated air mixture: saturated air mixture is a mixture of dry air and water vapour in which the partial pressure of the vapour is equal to the saturation pressure of water at the temperature of the mixture.ģ Unsaturated air mixture: it is a mixture of dry air and super heated water vapour. The amount of water vapour varies according to the temperature of air and reaches saturation at one point. Moist air: it is the mixture of dry air and water vapour. Air contains 79% nitrogen, 21% oxygen by volume and has a molecular weight of 29. Dry air: it is the mixture of nitrogen, oxygen and small percentage of other gases. SATHEESH KUMAR, DEPT OF MECH, MITE MOODABIDRI.Ģ PSYCHROMETRY The study of the properties of air and vapour pertaining to air conditioning problems is called psychrometry. After the war, food processing plants became the next big market for “manufactured weather.Chapter 7 PSYCHROMETRY N. As the war progressed, air conditioning in textile plants and candy factories also proved lucrative. Fuses and some explosive compounds in bomb manufacturing could not be produced in unstable indoor environments. Two years later, the nascent company’s biggest customers were munitions makers who clambered for technology to control indoor humidity, which helped reduce static charges that could touch off explosions around flash powder. Carrier and Lyle weren’t ready to abandon the project, and with five other engineers, founded the Carrier Engineering Corp.
As labor and material grew scarce, the company scaled back to its original lines. backed off from it when the country entered World War I. While the business took off, the Buffalo Forge Co. A 1921 newspaper ad notes, “You can manufacture weather” (photo right). Bolling created “Mech”, coined the terms "Weathermakers to the World" and "Manufactured Weather”, and challenged customers to "Make Every Day a Good Day," a reminder that air conditioning meant efficient production in all weather. In 1919, Carrier hired Esten "Jack" Bolling as their first "Publicity Engineer”.
Image courtesy Carrier Corporation Carrier Engineering Corp.’s early marketing efforts featured a cartoon mascot, The Mechanical Weather Man (aka “Mech”), whose control-valve body touted “Every Day a Good Day” (photo left).
0 kommentar(er)
