Psychrometric chart download pdf

Psychrometric chart download pdf

Psychrometry charts and humidity,Psychrometry charts and humidity

08/04/ · Identify 2 known measurements that are on the chart. Use a ruler to locate other measurements at the point of intersection. Visualize 2 measurements by comparing them on Fillable and printable Psychrometric Chart Fill, sign and download Psychrometric Chart online on blogger.com My Account. Login. Home > Miscellaneous Forms > Psychrometric Psychrometric Chart Pdf Free Download Talk to an Admission Officer Psychrometrics is the science of how to calculate the thermodynamic properties of moist air. Psychometric charts 4 Psychrometric Chart free download. Download free printable Psychrometric Chart samples in PDF, Word and Excel formats Power of Attorney; All Forms; HOME. Miscellaneous. Download (colored) Psychrometric Chart (si Units) Type: PDF. Date: November Size: 95KB. Author: Mc Jason Laurete. This document was uploaded by user and they confirmed ... read more

It can be very helpful in troubleshooting and finding solutions to greenhouse or livestock building environmental problems. It is used in calculating cooling loads and selecting mechanical equipment like enthalpy wheels, heat exchangers air , air handlers, and fan coils. You can download the Psychometric Chart PDF from the download button given below. We hope you find this content useful and are able to download the PDF for the Psychometric Chart. Nenad Sarunac. CeCy Joplin. carlos andres. Patricia Real. Quang Nguyen. Ayan Saha Roy. Suresh Kaushik. JZ cls. Kiet Nguyen Tuan. Muhammed Nihal. ehsan amirabedin. Eric Roe. Xuân Hoàng. Dániel Nagy. Eprillia Intan. Muhammed Aghamirzayev. adejoke odumosu. Jessie Bitog. Log in with Facebook Log in with Google.

Remember me on this computer. Enter the email address you signed up with and we'll email you a reset link. Need an account? Click here to sign up. Download Free PDF. Psychrometry charts and humidity. Muhammad Sadiq. Related Papers. WALAS S Chemical Process Equipment Selection and Design. Download Free PDF View PDF. Chemical Process Equipment - Selection and Design Walas. Chemical Process Equipment - Selection and Design Walas 1. Chemical Process Equipment. Selection and Desing by Stanley Walas. Chemical Process Equipment Selection and Design, Third Edition. Handbook of Industrial Drying. PAPER PROYECTO PIRO. Improving Process Profitability Continuously sm.

Mass Transfer Operations for the Practicing Engineer. Section 1 2 Psychrometry, Eva pora tive Cooling, a nd Solids Drying Cha rles G. M oyers, Ph D. Section Editor, Evaporative Cooling and Solids Drying Glenn W. Ba ldw in, M. Psychrometry PSYCHRO M ETRY Fogging and Plume Abatement. All rights reserved. Use of this product is subject to the terms of its license agreement. Click here to view. SI and Drying Tests. units are listed. Specialized symbols are either defined at the Batch Tray and Dryers. customary units Field of Application. July McGraw-Hill, New York, I, Reinhold, New York, Under ordinary conditions the partial pressure and Psychrometry is concerned with determination of the properties of vapor pressure are small relative to the total pressure, and the wet- gas-vapor mixtures.

The air-water vapor system is by far the system bulb equation can be written in terms of humidity differences as most commonly encountered. This has the will drop and its humidity will increase. If ts is such that the air leaving effect of making the adiabatic-saturation temperature different from the system is in equilibrium with the water, ts will be the adiabatic- the wet-bulb temperature. Thus, for systems other than air-water saturation temperature, and the line relating the temperature and vapor, calculation of psychrometric and drying problems is compli- humidity of the air is the adiabatic-saturation line.

The equation for cated by the necessity for point-to-point calculation of the tempera- the adiabatic-saturation line is ture of the evaporating surface. For other systems, the temperature of the RELATIO N BETW EEN W ET-BULB AN D evaporating surface would change. Terminology and relationships pertinent to psychrometry are: Under these conditions the wet-bulb temperatures and adiabatic- Absolute humidity H equals the pounds of water vapor carried by saturation temperatures are substantially equal and can be used inter- 1 lb of dry air. effect is unimportant for most engineering calculations. An empirical When the partial pressure p of water vapor in the air at a given tem- formula for wet-bulb temperature determination of moist air at atmos- perature equals the vapor pressure of water ps at the same tempera- pheric pressure is presented by Liley [Int.

of Mechanical Engineer- ture, the air is saturated and the absolute humidity is designated the ing Education, vol. saturation humidity Hs. water vapor in air divided by the vapor pressure of water at the given Chem. For low humidities this analogy gives temperature. All properties should be evaluated for the gas mixture. ture it contains. obtained a correlation for their data on sublimation of cylinders into Humid volume is the volume in cubic feet of 1 lb of dry air and the air and for the data of others on wet-bulb thermometers. For wet-bulb water vapor it contains. thermometers in air they give Saturated volume is the humid volume when the air is saturated. For evapo- face by convection equals the rate of mass transfer away from the sur- ration into gases other than air, Eq.

At equilibrium, if negligible change in the dry-bulb temperature would apply. is assumed, a heat balance on the surface is Application of these equations is illustrated in Example 1. Psychrometry 1 2 -3 Copyright © by The McGraw-Hill Companies, Inc. From Eq. The adiabatic-saturation temperature is obtained from Eq. Values of Hs and ts are given by the saturation curve of the psychrometric chart, such as Fig. properties of moist air when the dry-bulb temperature is 80°F and the wet-bulb temperature is 67°F. Read directly from Fig. Three charts for the air-water vapor system are given as Figs. These charts are for an absolute pressure of 1 atm. Determine the quantity of heat added per pound of dry air. Reading directly from the psychrometric chart Fig. Barometric pressure, To convert British thermal units per pound to joules per kilogram, multiply by ; to convert British thermal units per pound dry air-degree Fahrenheit to joules per kilogram-kelvin, multiply by Copyright © by The McGraw-Hill Companies, Inc.

PSYCHRO M ETRY 1 2 -5 FIG. To convert British thermal units per pound dry air-degree Fahrenheit to joules per kilogram-kelvin, multiply by Figure shows the heating is maintained at 20°F. path on the psychrometric chart. The path followed on a psychrometric chart is shown in Fig. Figure shows the path on a psychrometric chart. The only change in enthalpy is that diagram of Fig. The path followed is shown in Fig. To convert British thermal units per pound to joules per kilogram, multiply by ; to convert British thermal units per pound dry air-degree Fahrenheit to joules per kilogram- kelvin, multiply by PSYCHRO M ETRY 1 2 -7 FIG.

To convert British thermal units per pound to joules per kilo- gram, multiply by ; to convert British thermal units per pound dry air-degree Fahrenheit to joules per kilogram- kelvin, multiply by dry air B. dry air Enthalpy, B. humidity B. Hg Temp. t, °F. Goff and S. See also Keenan and Kaye. Thermodynamic Properties of Air, Wiley, New York, Enthalpy of dry air taken as zero at 0°F. Enthalpy of liquid water taken as zero at 32°F. PSYCHRO M ETRY 1 2 -9 TABLE 1 2 -1 Therm odyna mic Properties of M oist Air Sta nda rd Atmospheric Pressure, 2 9. PSYCHRO M ETRY 1 2 -1 1 TABLE 1 2 -2 Additive Corrections for H, h, a nd v W hen Ba rometric Pressure Differs from Sta nda rd Ba rometer Concluded Approximate altitude in feet Wet- Sat. dry air. From previous equation 0. of Fig. The air entering the dryer has a dry-bulb tem- perature of °F and a wet-bulb temperature of °F.

The air leaves the dryer at °F. A portion of the air is recirculated after mixing with room air having a dry-bulb temperature of 75°F and a relative humidity of 60 percent. Determine quantity of air required, recirculation rate, and load on the preheater if it is assumed that the system is adiabatic. Neglect heatup of the feed and of the con- veying equipment. The partial pressure of water vapor is calculated from Eq. At the HP 0. Air volume is 10, Thus air is recirculated. Additive corrections to be applied to the atmospheric values of absolute humidity and enthalpy are given in Table M EASUREM EN T O F HUM IDITY The specific volume of moist air in cubic feet per pound of dry air Dew-Point Method The dew point of wet air is measured can be determined for other pressures, if ideal-gas behavior is directly by observing the temperature at which moisture begins to assumed, by the following equation: form on an artificially cooled polished surface.

The polished surface is 0. the polished surface or to eliminate gradients across the surface. It is Relative humidity and dew point can be determined for other also difficult to detect the appearance or disappearance of fog; the than atmospheric pressure from the partial pressure of water in the usual practice is to take the dew point as the average of the tempera- mixture and from the vapor pressure of water vapor. The partial pres- tures when fog first appears on cooling and disappears on heating. The dew point of the from charts such as Figs. In order to obtain reliable mixture is then read directly from a table of vapor pressures as the information, care must be exercised to ensure that the wet-bulb ther- temperature corresponding to the calculated partial pressure. mometer remains wet and that radiation to the bulb is minimized. The The relative humidity is obtained by dividing the calculated partial latter is accomplished by making the relative velocity between wick pressure by the vapor pressure of water at the dry-bulb temperature.

and gas stream high [a velocity of 4. Again, as with the dew-point method, errors associated dry-bulb temperature, inHg. with the measurement of temperature can cause difficulty. The preceding equations, which have assumed that both the air and For measurement of atmospheric humidities the sling psychrom- the water vapor behave as ideal gases, are sufficiently accurate for eter is widely used. This is composed of a wet- and dry-bulb ther- most engineering calculations. If it is desired to remove the restriction mometer mounted in a sling which is whirled manually to give the that water vapor behave as an ideal gas, the actual density ratio should desired gas velocity across the bulb.

In the Assmann psychrometer be used in place of the molecular-weight ratio in Eqs. In addition to the mercury-in-glass thermometer, other tempera- Since the Schmidt number, Prandtl number, latent heat of vapor- ture-sensing elements may be used for psychrometers. These include ization, and humid heat are all essentially independent of pressure, resistance thermometers, thermocouples, bimetal thermometers, and the adiabatic-saturation-temperature and wet-bulb-temperature lines thermistors. will be substantially equal at pressures different from atmospheric. Mechanical Hygrometers Materials such as human hair, wood Example 8: Determination of Air Properties For a barometric fiber, and plastics have been used to measure humidity. These meth- pressure of bulb temperature of 70°F determine the following: absolute humidity, enthalpy, Electric hygrometers measure the electrical resistance of a film dew point, relative humidity, and specific volume.

of moisture-absorbing materials exposed to the gas. A wide variety of Solution. From Fig. air additive correction for air saturated at the wet-bulb temperature. See footnotes for Table passed over a moisture-absorbing chemical such as phosphorus pent- The enthalpy is obtained from Fig. oxide, and the increase in weight is determined. The air operating line neers, Atlanta, Counterflow Cooling Tower Performance, Pritchard begins at C, vertically below B and at a point having an enthalpy cor- Corporation, Kansas City, Mo. responding to that of the entering wet-bulb temperature. Line BC Piping Air Cond. October Kelley and Swenson, Chem. McAdams, Heat Transmission, 3d ed. In cooling water 1°F, the , pp. Merkel, Z. The Par- enthalpy per pound of air is increased 1 Btu multiplied by the ratio of allel Path Wet-Dry Cooling Tower, Marley Co.

Per- pounds of water per pound of air. Plume Abatement of the operating line. The air leaving the tower is represented by point and Water Conservation with Wet-Dry Cooling Tower, Marley Co. The cooling range is the projected length of line CD on the tem- Woods, Kan. RP-5, RP-5, Marley Co. The cooling-tower approach is shown on the diagram Woods, Kan. Wood and Betts, Engineer, , , , as the difference between the cold-water temperature leaving the Zivi and Brand, Refrig. tower and the ambient wet-bulb temperature. The coordinates refer directly to the temperature and enthalpy of PRIN CIPLES any point on the water operating line but refer directly only to the enthalpy of a point on the air operating line.

The corresponding wet- The processes of cooling water are among the oldest known. Usually bulb temperature of any point on CD is found by projecting the point water is cooled by exposing its surface to air. Some of the processes are horizontally to the saturation curve, then vertically to the temperature slow, such as the cooling of water on the surface of a pond; others are coordinate. The integral [Eq. These in the diagram. If the cooling range increases, line CD lengthens. At fer owing to the difference in temperature of water and air. On the other percent to sensible heat. cooling tower depends on the temperature and moisture content of In order to predict tower performance it is necessary to know the air. An indication of the moisture content of the air is its wet-bulb tem- required tower characteristics for fixed ambient and water conditions. retical temperature to which the water can be cooled. Important factors are air-to-water contact time, amount of fill surface, and breakup of water into droplets.

In actual practice, cooling towers are seldom designed for approaches closer than 2. CO O LIN G-TO W ER THEO RY The most generally accepted theory of the cooling-tower heat-transfer process is that developed by Merkel op. This analysis is based upon enthalpy potential difference as the driving force. Each particle of water is assumed to be surrounded by a film of air, and the enthalpy difference between the film and surrounding air pro- vides the driving force for the cooling process. The right-hand side of Eq. Figure illustrates water and air relationships and the driving potential which exist in a counterflow tower, where air flows parallel but opposite in direction to water flow.

An understanding of this dia- gram is important in visualizing the cooling-tower process. Marley Co. Norris, Robert W. Norris and Associates, Inc. Evaporative Cooling Copyright © by The McGraw-Hill Companies, Inc. Once the theoretical cooling-tower characteristic has been deter- From air-water vapor-mixture tables, the enthalpy h1 of the ambient air at mined by numerical integration or from the nomograph for a given 78°F wet-bulb temperature is cooling duty, it is necessary to design the cooling-tower fill and air dis- tribution to meet the theoretical tower characteristic. has developed performance data on various T, °F. These data are too extensive to include here, and those interested should consult this reference. RP, Mission Woods, Kan. In the forced-draft tower the fan is L 4 mounted at the base, and air is forced in at the bottom and discharged A quicker but less accurate method is by the use of a nomograph at low velocity through the top.

This arrangement has the advantage of Fig. Since the equipment is out of ratios ranging from 0. With these ranges in mind, an example of the use of sive conditions. However, because of the low exit-air velocity, the the nomograph will readily explain the effect of changing variables. forced-draft tower is subjected to excessive recirculation of the humid FIG. Since the wet-bulb tempera- ture of the exhaust air is considerably above the wet-bulb temperature of the ambient air, there is a decrease in performance evidenced by an increase in cold leaving -water temperature. The induced-draft tower is the most common type used in the United States. It is further classified into counterflow and cross-flow design, depending on the relative flow directions of water and air.

Thermodynamically, the counterflow arrangement is more effi- cient, since the coldest water contacts the coldest air, thus obtaining maximum enthalpy potential. The greater the cooling ranges and the more difficult the approaches, the more distinct are the advantages of the counterflow type. The chart will give approx- teristic of 1. Ecodyne Corp. requires a characteristic of 2. However, if the approach is increased to 3. computation, the manufacturer should be consulted for final design The cross-flow-tower manufacturer may effectively reduce the recommendations.

The increase in air flow is not necessar- filling varies with the water concentration. It has been found that ily achieved by increasing the air velocity but primarily by lengthening maximum contact and performance are obtained with a tower having a the tower to increase the air-flow cross-sectional area. Thus the that the cross-flow fill can be made progressively longer in the direc- problem of calculating the size of a cooling tower becomes one of tion perpendicular to the air flow and shorter in the direction of the air determining the proper concentration of water required to obtain the flow until it almost loses its inherent potential-difference disadvan- desired results.

Once the necessary water concentration has been tage. However, as this is done, fan power consumption increases. established, tower area can be calculated by dividing the gallons per Ultimately, the economic choice between counterflow and cross- minute circulated by the water concentration in gallons per minute- flow is determined by the effectiveness of the fill, design conditions, square foot. The required tower size then is a function of the following: and the costs of tower manufacture. Cooling range hot-water temperature minus cold-water tem- Performance of a given type of cooling tower is governed by the perature ratio of the weights of air to water and the time of contact between 2. Approach to wet-bulb temperature cold-water temperature water and air. In commercial practice, the variation in the ratio of air minus wet-bulb temperature to water is first obtained by keeping the air velocity constant at about 3.

As a secondary operation, air velocity 5. Air velocity through the cell is varied to make the tower accommodate the cooling requirement. Tower height Time of contact between water and air is governed largely by the time required for the water to discharge from the nozzles and fall Example Application of Sizing and Horsepower Charts through the tower to the basin. The time of contact is therefore To illustrate the use of the charts, assume the following conditions: obtained in a given type of unit by varying the height of the tower. It is therefore necessary to maintain a certain minimum height of cooling tower. The area of the tower is calculated as ft2 quantity of basin is sufficient. When a moderate approach and a cooling range of water circulated divided by water concentration.

Connecting the point repre- travels 7. Where a close approach senting percent of standard tower performance with the turning point and extending this straight line to the horsepower scale show that it will require of 4. For a tower area of ft2 It is usually not economical to design a cooling tower Suppose that the actual commercial tower size has an area of only ft2. with an approach of less than 2. However, this requires boosting fan to 40 ft. horsepower to achieve percent of standard tower performance. Figure shows the relationship of the hot-water, cold-water, , the fan horsepower is found to be 0. On the other hand, if the actual commercial tower area is ft2, the cool- the minimum area required for a given performance of a well- ing equivalent to ft2 of standard tower area can be accomplished with less designed counterflow induced-draft cooling tower can be obtained.

air and less fan horsepower. These curves do not apply to paral- area, or lel or cross-flow cooling, since these processes are not so efficient as the counterflow process. Also, they do not apply when the approach to This example illustrates the sensitivity of fan horsepower to small the cold-water temperature is less than 2. These charts changes in tower area. The importance of designing a tower that is should be considered approximate and for preliminary estimates only. slightly oversize in ground area and of providing plenty of fan capacity Since many factors not shown in the graphs must be included in the becomes immediately apparent. Met- all. Drift loss is a function of the drift-eliminator design, which typically varies between 0. New developments in eliminator design make it possible to reduce drift loss well below 0. Blowdown discards a portion of the concentrated circulating water [Fluor Corp.

now Ecodyne Corp. The amount of blowdown can be calculated according to Example Application of Sizing Chart Assume the same cool- the number of cycles of concentration required to limit scale forma- ing range and approach as used in Example 11 except that the wet-bulb tem- tion. Cycles of concentration are the ratio of dissolved solids in the perature is lower. Design conditions would then be recirculating water to dissolved solids in the makeup water. Below three cycles of concen- bulb temperature. This shows that the lower the wet-bulb temperature for the tration, excessive blowdown quantities are required and the addition same cooling range and approach, the larger is the area of the tower required of acid to limit scale formation should be considered.

and therefore the more difficult is the cooling job. Example Calculation of Makeup Water Determine the Figure illustrates the type of performance curve furnished by amount of makeup required for a cooling tower with the following conditions: the cooling-tower manufacturer. Inlet water temperature, °C °F Large air quantities are circulated through cooling towers at exit velocities of about Fan air-flow quantities depend upon tower-design factors, including such items as type of fill, tower configuration, and thermal- performance conditions. The effective output of the fan is static air horsepower SAHP , FIG.

which is obtained by the following equation: Copyright © by The McGraw-Hill Companies, Inc. head equal to static lift plus nozzle pressure loss. A cross-flow type of Cooling-tower fan horsepower can be reduced substantially as the tower with gravity flow enables a pumping head to equal static lift. A ambient wet-bulb temperature decreases if two-speed fan motors are reduction in tower height therefore reduces static lift, thus reducing used. Theoretically, operating at half speed will reduce air flow by 50 pump horsepower: percent while decreasing horsepower to one-eighth of full-speed operation. Figure shows a typical plot of outlet-water temperatures Fogging and Plume Abatement A phenomenon that occurs in when a cooling tower is operated 1 in the fan-off position, 2 with cooling-tower operation is fogging, which produces a highly visible the fan at half speed, and 3 with the fan at full speed.

Note that at plume and possible icing hazards. Fogging results from mixing warm, decreasing wet-bulb temperatures the water leaving the tower during highly saturated tower discharge air with cooler ambient air that lacks half-speed operation could meet design water-temperature require- the capacity to absorb all the moisture as vapor. While in the past vis- ments of, say, 85°F. For example, for a 60°F wet-bulb, 20°F range, a ible plumes have not been considered undesirable, properly locating leaving-water temperature slightly below 85°F is obtained with design towers to minimize possible sources of complaints has now received water flow over the tower. If the fan had a hp motor, 83 hp would the necessary attention.

In some instances, guyed high fan stacks have be saved when operating it at half speed. In calculating savings, one been used to reduce ground fog. Although tall stacks minimize the should not overlook the advantage of having colder tower water avail- ground effects of plumes, they can do nothing about water-vapor sat- able for the overall water-circulating system. uration or visibility. The persistence of plumes is much greater in peri- Recent developments in cooling-tower fan energy management ods of low ambient temperatures. also include automatic variable-pitch propeller-type fans and inverter- More recently, environmental aspects have caused public aware- type devices to permit variable fan speeds.

These schemes involve ness and concern over any visible plume, although many lay persons tracking the load at a constant leaving-water temperature. misconstrue cooling-tower discharge as harmful. This has resulted in The variable-pitch arrangement at constant motor speed changes a new development for plume abatement known as a wet-dry cooling- the pitch of the blades through a pneumatic signal from the leaving- tower configuration. Reducing the relative humidity or moisture con- water temperature. been demonstrated to be technically sound but at substantially Inverters make it possible to control a variable-speed fan by chang- increased tower investment.

Ambient air travels in parallel streams ing the frequency modulation. Standard alternating-current fan motors through the top dry-surface section and the evaporative section. Both may be speed-regulated between 0 and 60 Hz. In using inverters for sections benefit thermally by receiving cooler ambient air with the wet this application, it is important to avoid frequencies that would result and dry air streams mixing after leaving their respective sections. in fan critical speeds. Water flow is arranged in series, first flowing to the dry-coil section Even though tower-fan energy savings can result from these arrange- and then to the evaporation-fill section. Power-plant arrangement, in which dry coil sections can be located before or after steam condensers and refrigeration units, for example, can take advan- the air traverses the evaporative section, also can be used.

However, tage of colder tower water to reduce power consumption. Invariably, series-path air flow has the disadvantage of water impingement, which these system savings are much larger than cooling-tower fan savings could result in coil scaling and restricted air flow. with constant leaving-water temperatures. A refrigeration-unit con- Wet-dry cooling towers incorporating these designs are being used denser can utilize inlet-water temperatures down to At present they are not avail- reduce compressor energy consumption by 25 to 30 percent. able for commercial applications. During periods water is available at a temperature lower than the required chilled- below 50°F ambient wet-bulb temperatures, cooling towers have the water-supply temperature.

Modifications for a centrifugal refrigera- temperature capability to furnish chilled water directly to air- tion unit include the installation of a small liquid-refrigerant pump, conditioning systems. For existing refrigeration—cooling-tower sys- cooler spray header nozzles, and a vapor bypass line between the tems, piping can be installed to bypass the chiller to allow tower cooler and the condenser. Without the compressor operating, a ther- effluent to flow directly to cooling coils. After heat has been removed mocycle capacity up to 35 percent of the refrigeration-unit rating can from the air stream, water returns directly to the cooling tower. Water be produced. temperature leaving the cooling tower is controlled between 8.

est water temperature possible for a given ambient wet-bulb tempera- Depending upon the cleanliness of the cooling-tower water, it may be ture. The large vapor bypass between the cooler and the condenser is necessary to install a side-stream or full-flow filter to minimize conta- opened along with the compressor suction damper or prerotational mination of the normally closed chilled-water circuit. Figure vanes. The heat removed from the chilled-water stream boils off refrig- shows the general arrangement of this system. Substantial savings can erant vapor from the cooler. This vapor flows mainly through the be realized during colder months by eliminating refrigeration- bypass line to the condenser, where it is condensed to a liquid. Units compressor energy. having hot-gas bypass lines cannot be used for this purpose, as the pipe Several other methods involving cooling towers have been used to size is too small.

The liquid then returns to the cooler as in the normal reduce refrigeration energy consumption. These systems, as applied refrigeration cycle. If the refrigeration unit contains internal float to centrifugal and absorption refrigeration machines, are known as valves, they are bypassed manually or held open by an adjusting stem. thermocycle or free cooling systems. When water leaving the cooling Thermocycle capacity is a function of the temperature difference tower is available below 10°C 50°F , the thermocycle system permits between the chilled-water outlet temperature leaving the cooler and shutting down the compressor prime mover or reducing steam flow to the inlet condenser water.

The cycle finally stops when these two an absorption unit. Figure shows the arrangement for a cen- temperatures approach each other and there is not sufficient vapor trifugal refrigeration unit. pressure difference to permit flow between the heat exchangers. Precise control of the outlet chilled-water temperature does not In operating a cooling tower in the thermocycle or free-cooling occur with thermocycle operation. This temperature is dependent on mode, some precautions are necessary to minimize icing problems. ambient wet-bulb-temperature conditions. Normally, during cold These include fan reversals to circulate air down through the tower winter days little change occurs in wet-bulb temperatures, so that only inlet louvers, proper water distribution, constant water flow over the slight water-temperature variations may occur.

This would not be true tower, heat tracing of lines such as makeup lines as required, and max- of many spring and fall days, when relatively large climatic tempera- imum loading per tower cell. ture swings can and do occur. Refrigeration units modified for free cooling do not include the liq- N ATURAL-DRAFT TO W ERS uid-refrigerant pump and cooler spray header nozzles. As you may know, psychrometry is the study of the properties of air-water mixtures. On a psychrometric chart, there are lines that represent different properties of the mixture.

For example, one line might represent dew point temperature and another line might represent relative humidity. There are also curves that show changes in properties over time. For example, one curve might show how the relative humidity changes over time. Because these lines and curves represent different properties of air-water mixtures, they will cross each other at different points on the chart. This makes it easy for you to compare how two different properties relate to each other. Welcome to infolearners; A book website where you can read eBook, novels and other educational materials free online. This ebook website is useful for any student. You will find Psychrometric Chart Pdf and other useful educational materials that are very relevant to your interest. The psychrometric chart is the graphic representation of the thermodynamic properties of moist air. The psychrometric chart shows the interrelationships between various physical and thermodynamic parameters of moist air.

It is a very useful tool for HVAC engineers because it allows them to perform cooling and heating calculations easily and quickly, by simply looking at the diagram.

Welcome to our new post. In this post, we will provide you with a PDF of the Psychometric Chart. You can find the Psychometric Chart for Engineers, which you can also download in PDF format at the end of this post. A psychrometric chart presents the physical and thermal properties of moist air in a graphical form. It can be very helpful in troubleshooting and finding solutions to greenhouse or livestock building environmental problems. It is used in calculating cooling loads and selecting mechanical equipment like enthalpy wheels, heat exchangers air , air handlers, and fan coils. You can download the Psychometric Chart PDF from the download button given below. We hope you find this content useful and are able to download the PDF for the Psychometric Chart. Save my name, email, and website in this browser for the next time I comment. Download Color Psychometric chart PDF for HVAC and Refrigeration Engineers.

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Psychrometric Chart Pdf Free Download,Psychometric Chart

-5 0 5 10 15 20 25 30 35 40 45 50 55 60 dry bulb temperature - °c 5 10 15 20 25 30 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 08/04/ · Identify 2 known measurements that are on the chart. Use a ruler to locate other measurements at the point of intersection. Visualize 2 measurements by comparing them on B.3 TABLE B.1 Thermodynamic Properties of Moist Air (at Atmospheric Pressure psia) and Water Humidity Volume, Enthalpy, Saturated water vapor Enthalpy, Btu/lb Temp ratio w s, Psychrometric Chart Pdf Free Download Talk to an Admission Officer Psychrometrics is the science of how to calculate the thermodynamic properties of moist air. Psychometric charts PSYCHROMETRIC CHART Normal Temperature SI Units SEA LEVEL -5 0 5 10 15 20 25 30 35 40 0 10 20 30 40 50 60 70 80 90 ENTHALPY - KJ PER KILOGRAM OF DRY AIR 0 2 4 6 8 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 dry bulb temperature - °c 5 10 15 20 25 30 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 ... read more

This case would ings range usually from 1 to 10 cm deep. temperatures Direct rotary. Metal trays are preferable 3. curve represents the general case when a wet solid loses moisture first Hougen, McCauley, and Marshall [Trans. This is often the sim- overall heat-transfer coefficient or length of a transfer unit as plest way to achieve increased capacity.

als are given in Table for drying by cross circulation and in Table An approximate equation for the falling-rate period may be for drying by through circulation. liquors, psychrometric chart download pdf, rubber clay slip, lead con- itates, pigments, Type of dryer latex, etc. The time of contact is therefore To illustrate the use of the charts, assume the following conditions: obtained in a given type of unit by varying the height of the tower. Movement within the solid applies to liquids not held in solution and to all moisture above the results from a concentration gradient which is dependent on the char- fiber-saturation psychrometric chart download pdf, as in textiles, paper, and leather, and to all mois- acteristics of the solid. Psychrometry charts and humidity. The chart will give approx- teristic of 1. Heat is lost through evaporation, convection, and radiation and is gained through solar radiation.