Pdf evaporative cooling of wet soil surface under different. In this type of system the air temperature can be lowered to match the wet bulb temperature. Recycled highdensity polyethylene and rice husk as a wetted pad in evaporative cooling system article in american journal of applied sciences 82. Kind of mass really doesnt matter as long as there is enough of it. Review and cite solar cooling protocol, troubleshooting and other methodology information contact experts in solar cooling to get answers. Us20070151278a1 subwet bulb evaporative chiller with pre. Recycled highdensity polyethylene and rice husk as a. Choice a choice b choice c choice d choice e choice f. Nagam obaid kariem college of engineering al mustansiry university abstract this research work is to study the performance of evaporative cooling system using new type of packing with different shapes.
The slope in its upper part is a cliff subject to rock falls and in its lower part a talus slope or fan deposit built by debris flows. Ice, although it is solid, does have the ability to flow, and freezing and thawing cycles can also contribute to movement. That includes all earth materials, rock and regolith. Mass wasting is the downslope movement of material under the influence of gravity. Evaporative cooling system for storage of fruits and vegetables a. Which of the following types of mass wasting best describes this slope failure. It shows that there is stay water not used for evaporative cooling in the system after capillary absorption channel from the pavement downside to the surface are disconnected. Describe one change in the evaporative cooling system that would allow more cool air to be produced. Model epx uses a corrosionresistant polymer heat exchanger to produce dry, cool air without using refrigeration. An evaporative and desiccant cooling system for an. For each item below, use the pulldown menu to select the letter that labels the correct part of the image. Evaporative coolers, often called swamp coolers, are cooling systems that use only water and a blower to circulate air. What roles do climate and weathering play in mass wasting.
Types of mass wasting processes defined by the movement of the material the character of the movement fall slide flow types of mass wasting processes defined by the movement of the material the rate of the movement fast slow forms of mass wasting slump rockslide debris flow earth flow creep solifluction. Iec modelling a schematic diagram of the countercurrent type iec is. Match the description with the appropriate label on the diagram of mass wasting types. Heat and mass transfer in open evaporative cooling system. One of the main challenges in the field of soil modeling prediction or classification such as digital. In utah, they are common in the spring and fall because of freezethaw weathering. Evaporative cooling an overview sciencedirect topics. The cooling system the purpose of the engines cooling system is to remove excess heat from the engine, to keep the engine operating at its most efficient temperature, and to get the engine up to the correct temperature as soon as possible after starting. After an unusually heavy rainfall, the slope failed very quickly along a curved surface. The research areas of our faculty members, as well as their current and recent research projects, are listed below. The work of gravity earth 9thedition chapter 15 mass wasting. Experimental study on the impact of mass moisture content on the evaporative cooling effect of porous face brick. A variety of conditions affect the development of mass wasting in a particular area. Although cooling towers can be classified several ways, the primary classification is into dry.
In the fargomoorhead region, three types of mass wasting impact slopes bordering the red river and its tributaries. So, in a dec, water is vaporized in the airstreams and the heat and mass exchanged between air and water decrease the air dry bulb temperature dbt and increase its humidity, keeping constant the. Varieties of these are called earthflows, mudflows, and debris avalanches. Pdf laboratory evaporation studies were conducted to assess the roles. Evaporative cooling is used in both biological and mechanical processes. Subwet bulb chilling is achieved by pre cooling incoming air upstream of the saturator.
Debris flows and torrents commonly entrain large quantities of inorganic and organic material from the stream bed and banks. Pdf evaporative cooling of water in a mechanical draft cooling tower. When momentum is lost, scoured debris may be deposited as a tangled mass of large organic debris in a matrix of sediment and finer organic material. Heat and mass transfer in open evaporative cooling system using various types of fills in oil industry dr. Indirect evaporative cooling techniques also exist, in which the air is cooled without increasing its water vapor content. Dec 23, 20 during a brisk run, an adult human generates heat at a rate of about 20 w. In the process, trash from the base of the slope was removed and piled on top of the landfill. Hence, preserving these types of foods in their fresh form demands that. The quiz will test you on the characteristics of mass wasting.
Slump can result in major and rapid slope retreat, especially in regions of river cutbanks. The latent heat of vaporization of water at 37 c typical body temperature is 24. As with gases, ficks diffusion equation describes the movement of water across the skin. Pdf design and performance analysis of a small solar. Matthew becker, conrey endowed chair, hydrogeology. Mass wasting is more prone on slopes that contain clay and shale. We are designing a home evaporative cooling system. Thus, these bricks are promising for use as a passive energysaving building technology. Evaporative cooling is a cost effective, efficient method of cooling air compared to conventional airconditioning.
Mass wasting of regolith in semiarid climates leads to hill slopes that are concave up. The evaporative cooled storage structure has proved to be useful for. Personal thermal comfort is a function of personal health factors medical, psychological, sociological and situational, ambient air temperature, mean radiant temperature, air movement wind chill, turbulence and relative humidity affecting human evaporative cooling. The occurrence and characterization of fouling during. Frost heaving this process is large contributor to creep in cold climates.
Conventional iec heat and mass exchanger a working principle of the indirect evaporative cooling b configuration of the type iec heat and mass exchanger c psychrometric illustration of the air treatment process in the iec heat and mass exchange iii. When water is used as the heat transfer medium, wet, or evaporative, cooling towers. Mass emission measurements performed on kerrmcgee chemical. Experimental performance analysis of a solar evaporative cooler with three different types of pads article in journal of renewable and sustainable energy 56. All of these processes generally grade into one another, so classification of such processes is somewhat difficult. Types of mass wasting a rock fall are the fastest of all landslide types and occurs when a rock falls through the air until it comes to rest on the groundnot too complicated. Creep and earthflow, generally induce lesser amounts of damage, although these processes can occur on any slope. Our bodies are designed to sweat to release heat and keep our body at its natural temperature when it gets too hot. Theoretical analysis on heat and mass transfer in a direct. Mass wasting downhill movement of masses of bedrock, rock debris or soil, driven by the pull of gravity landslides have been far more costly in the u. Experimental performance analysis of a solar evaporative. Mass wasting in cold climates mass wasting in cold climates.
Identify whether the evaporative cooling system is an open system or a closed system. To maintain conservation of mass, descent must accompany the storms. It involves the movement of air past or through a moist material. The three criteria used to describe slope failures are. A light colored mass can reflect heat back outside through the very same windows and the rest ends up scattered in the room in low mass things which raise air temperature. The incoming air is ambient air at ambient air temperature that is cooled using the coolness of the lower temperature outgoing air exiting the saturator. Mass movements mass movements also called mass wasting is the downslope movement of regolith loose uncemented mixture of soil and rock particles that covers the earths surface by the force of gravity without the aid of a transporting medium such as water, ice, or wind. Steep slopes, widely varying altitude ranges relief, the thickness of the loose earth material, planes of weakness parallel to the slopes, frequent freezing and thawing, high water content in the earth material, dry conditions with occasional heavy rainfall, and sparse vegetation are the factors that. Water is a critical factor in mass wasting page 209. Several types of mass wasting are geologic hazards that are frequently responsible for loss of life. Types of mass movement processes the downslope movement of material, whether it be bedrock, regolith, or a mixture of these, is commonly referred to as a landslide. When earth material moves down a hillside as a fluidlike mass, it is called an earthflow. The one thing i will say on that issue though is color of the mass being heated by the sun does matter.
Significance of parameters affecting the performance of a. Mass wasting, also known as slope movement or mass movement, is the geomorphic process. The model epx indirect evaporative cooler uses a highefficiency, airtoair heat exchanger and indirect evaporative cooling to introduce 100% outdoor air while reducing cooling load tonnage. Mass wasting definition mass wasting refers to a downhill. Direct evaporative cooling the principle underlying direct evaporative cooling is the conversion of sensible heat to latent heat. Examples include the space shuttle, the apollo command and service. Evaporative cooling is the safest measure and includes cooling the patient with. Most mass movements are aided by weathering and involve surficial material. At a local landfill, the liner beneath the trash was being repaired. Slides, page 220 and also underwater landslides, page 224 to complete this answer question 7 see figures 9. Different types of evaporative devices such as wetted pads and water sprays are attached to wind towers in order to improve their performance, accelerating the direct evaporative cooling process by expanding direct contact between the incoming outdoor air and water added to the air stream via evaporation.
The water consumption is much lower than in direct systems. Types of mass wasting include creep, slides, flows, topples, and falls, each with its. The basis of the installation is the evaporative cooling system,1. We cannot prevent mass wasting, but we can delay it through efforts to strengthen the materials on slopes. Another factor that determines mass wasting is the slopes materia.
Experimental study of pavement body configurations of the. Gravity 159 m, the distance d2 from c to b is 121 m, and the speed vr of the current in the river is 5 kmhr. Many types of heat exchangers have been developed for use in steam power plants. We cant always predict or prevent the occurrence of masswasting events, a knowledge of the processes and their relationship to local geology can lead to intelligent planning that will help reduce losses of life and property controls and triggers of mass wasting important factors include. Design and performance analysis of a small solar evaporative cooler. Porous face bricks on the outside of a building wall exhibit evaporative cooling after absorbing water. Cooling tower management cooling towers dissipate heat from recirculating water used to cool chillers, air conditioners, or other process equipment to the ambient air. During a brisk run, an adult human generates heat at a rate. Evaporative cooling design guidelines manual for new mexico schools. Research geological sciences department california state. Pdf a heat exchanger is a heat transfer device that exchanges heat between two or more process fluids. To remove this heat by evaporative cooling, what mass of water per second mt must be evaporated from the body as sweat. The important types of mass wasting are creep, slump, translational slide, rotational slide, fall, and debris flow or mudflow. Identify the two fluids used in the evaporative cooling system.
An evaporative chiller cooling water to below ambient wet bulb temperature. Nonsaturated air is cooled by heat and mass transfer increases by forcing the movement of air through an enlarged liquid water surface area for evaporation by utilizing blowers or fans. Occasionally, the channel may be scoured to bedrock. Suppose that the swimmers velocity relative to the water makes an angle of. The type of material that failed typically either bedrock or unconsolidated sediment. This is one of the central concepts of this course. An evaporative cooler is a device that cools air through the evaporation of water. However, the additional air movement provided into the space can improve. Evaporative cooling of wet soil surface under different agricultural land.549 102 1374 489 697 284 798 1088 1041 260 1182 606 441 728 1268 625 918 1484 1379 1145 15 1190 690 659 1071 954 798 1263 985 1619 775 1493 858 1302 963 483 32 1387 1548 1017 207 1398 773 650 369 1030 825 452 902 47 1029