Would anyone be able to recommend a source for hot lime softener modeling software to help calculate lime, soda ash and mgo feed rates for treatment of a given water. Its severity is expressed in term of the biot number. Precipitative softening uses chemical precipitation to reduce hardness in source waters and improve clarification prior to filtration. Water resources engineering civil engineering engc 6305. In this process calcium and magnesium ions are precipitated by the addition of lime caoh2 and soda ash na2co3. This process is now obsolete but was very useful for the treatment of large volumes of hard water. Soda lime, white or grayish white granular mixture of calcium hydroxide with sodium hydroxide or potassium hydroxide.
Chemical precipitation is one of the more common methods used to soften water. Hot and cold lime soda process water applied chemistry i. We provide energy efficiency assessments for council building approvals for new homes, residential developments and alterations to existing residences. The two types differ in the application, production method float process for windows, blowing and pressing for containers, and chemical composition. Calcium carbonate total dissolve solid head loss softening process influent flow. In lime sodaash softening plants, the softening process may be carried out by a. Limesoda ash softening process 10 when lime and soda ash are added, hardnesscausing minerals form nearly insoluble precipitates. Hot and cold lime soda process video lecture from water chapter of applied chemistry i subject for all engineering students.
In problem, limesoda ash softening of the groundwater did. Chemicals normally used are lime calcium hydroxide, caoh 2 and soda ash sodium carbonate, na 2co 3. Ion exchange is an effective, versatile means of conditioning boiler feed water. Hello, currently i am working on hot lime softening project. Lime cannot remove the calcium permanent hardness which should be removed by soda. Lime soda process numerical water treatment, chemistry. Sodalime glass, also called sodalimesilica glass, is the most prevalent type of glass, used for windowpanes and glass containers bottles and jars for beverages, food, and some commodity items.
After flocculation, the water is allowed to flow into a. Cold lime soda process sodium carbonate calcium scribd. For waters with high calcium, high magnesium, and carbonate and noncarbonate hardness. Modern day processes for water softening usually treat the water in four steps to make is acceptable for human use. Wide variations in raw water composition and flow rate also make control of this method difficult since this involves adjusting the amounts of lime and soda ash. What is the hot lime soda process of water treatment. Lime soda water softening mcgrawhill education access.
Limesoda ash softening is assumed to be capable of reducing calcium and magnesium to empirically determined 11practical limits11 of 0. Soda ash is used to remove chemicals that cause noncarbonate. To be classified as limestone, the rock must contain at least 50 percent calcium carbonate. The two general types are intermittent batch type and continuous. These ions or minerals are normally addressed as scale in the water causing scaling of pipes and equipment in drinking water and process water systems. Chemical wood pulps such as soda and sulfite pulp described below are used when high brightness, strength, and permanence are required. The use of lime to soften water originated around 1841 when the thames river was treated for its bicarbonate hardness. The chemical mixing process is same as the cold lime soda process, but steam is applied in mixture tank. An ebook reader can be a software application for use on a computer such as microsofts free reader. A typical precipitative softening process includes rapid mix, flocculation, sedimentation, recarbonation, and filtration.
Hot lime soda process in the hot lime soda process the reactions take place at higher temperature near about boiling point of water. Computer simulation of limesoda water softening process. Although limestone deposits are found in every state, only a small portion is pure enough for industrial lime manufacturing. Base exchange ion exchange water softening process. Lime is used to remove chemicals that cause carbonate hardness. Simulation of limesoda softening northeastern university.
Limesoda water softening process and its advantages notes. When lime and soda ash are added to water, hardness causing minerals such as calcium and magnesium are precipitated out. Hardness is the term often used to characterize a water that. Lime softening, also known as clarks process, is a type of water treatment used for water softening which uses the addition of limewater calcium hydroxide to remove hardness calcium and magnesium ions by precipitation. Sodalime glass accounts for about 90% of manufactured glass. Medically, soda lime is used to absorb carbon dioxide in basal metabolism tests and in rebreathing anesthesia systems. Groundwood pulp was first made in germany in 1840, but the process did not come into extensive use until about 1870. There is also information about three lime soda water softening process alternatives two stage excess lime water softening, split treatment, and selective calcium removal, along with calculation of the dosages needed for lime, soda ash, and carbon dioxide. Lime reacts with temporary hardness, co 2, acids, bicarbonates and alums.
Lime soda process 9th lectureby ruchi upadhyay youtube. The basic principle in this method is to convert all the soluble hardness causing constituents into insoluble precipitates by appropriate chemical reactions. Some glass bakeware is made of sodalime glass, as opposed to the more common borosilicate glass. Lime and soda design is an independent specialist energy assessing consultancy. You should create your process flow diagram so that it focuses on major plant processes and not show minor details. The older method of intermittent softening consists of mixing the chemicals with the water in a tank, allowing time for reaction and settling of the sludge, and drawing off the clear water. Thank you guys for watching this video and intrepid geeks wants your support to provide finest education in india like intrepid geeks on facebook. Limesoda water softening process limitation of soda. Addition of lime cao and soda na 2 co 3 to the hard water precipitates calcium as the carbonate, and magnesium as its hydroxide.
A watersoftening process in which water is treated with hydrated lime sometimes in combination with soda ash, which reacts with dissolved calcium and magnesium compounds to form precipitates that can be removed as sludge. The lime may be in the form of quicklime cao or hydrated lime caoh 2, also called slaked lime. Soda lime absorbs carbon dioxide and water vapour and deteriorates rapidly unless kept in airtight containers. Sodalime glass consists of sand, limestone, soda ash, and cullet broken glass. Chemical requirement and product composition for limesoda softening is usually calculated using the bar diagram method and its variations 3,5. Schematic diagram of the limesoda process 5 download. Cold lime soda process free download as powerpoint presentation. Soda lime is a process used in water treatment to remove hardness from water. On the flow diagram, show the chemicals being added and their points of application. View subsections 7 limesoda softening 71 hardness 72 lime soda softening 73 softening processes 74 chemical dosages. Water supply and pollution control mit opencourseware. The soda process is useful for digesting softwood or hardwood. Chemistry assignment help, lime soda process numerical water treatment, while solving lime sida numericals we calculate caco3 equivalent.
Calculations are presented for daily chemical requirements and solids production rates. The chemistry of limesoda ash precipitation water softening. Lime soda process is one of the water softener systems. The process is also effective at removing a variety of microorganisms and dissolved organic matter by flocculation. In well plants water by softening the limesoda hard, process, clear well water. In lime sodaash softening plants, the softening process may be carried out by a sequence of. Perhaps just an excel spreadsheet program to share and perhaps build upon.
Limesoda water softening process limitation of soda lime. Effectiveness 80100 mgl as caco3 is usually considered acceptable result of limesoda ash softening, as long as mg is software available for convection heat transfer coefficients, pipe flowfriction factor calculations, partially full pipe flow calculations, watershed time of concentration, rational method, orifice and venturi meter flow rate calculations, open channel flow measurement, activated sludge wastewater. In this process, a suspension of calcium hydroxide lime and sodium carbonate soda is added to water in calculated quantities bases on the concentration of. Lime soda softening is the subject of this course, which includes coverage of calculating the different types of hardness in a water sample from lab analysis results, conversions among different units for hardness, information about three lime soda water softening process alternatives two stage excess lime water softening, split treatment, and. Limesoda ash softening is assumed to be capable of reducing calcium and magnesium. Sketch a preliminary process flow diagram to treat this groundwater for potable use.
A process flow diagram pfd, also known as a flowsheet, is a type of flowchart used by chemical and process engineers to illustrate highlevel processes. An alkaline chemical pulping process in which wood chips are digested in a caustic soda containing lye naoh, produced by adding sodium carbonate na 2 co3 to lime cao. Consider also the disposal of any process wastewaters. By this process soluble magnesium and calcium salts are removed as calcium carbonate and magnesium hydroxide precipitated. View subsections 7 limesoda softening 71 hardness 72 limesoda softening 73 softening processes 74 chemical dosages. As a result precipitation becomes almost complete very quickly. Hot and cold lime soda process 10th lecturer by ruchi upadhyay duration. What are the various methods of limesoda softening. An assessment of options for co 2 removal from the atmosphere. In problem, limesoda ash softening of the groundwater did not produce a treated water of drinking quality. In this system calcium hydroxide and soda ash are used as reagents.
Safety data sheet ghs product identifier other means of identification 24hour telephone section 1. Download scientific diagram schematic diagram of the limesoda process 5 from publication. The precipitated caco 3 and mgoh 2 are filtered off. What is a process flow diagram pfd a process flow diagram will consist of. The first commercial production of soda pulp was in 1851, and is used infrequently in the presentday due to the superiority of newer processes. Addition of lime cao and soda na2co3 to the hard water precipitates calcium as the carbonate, and magnesium as its hydroxide. Process flow diagram software free process flow diagram. Introduction lime soda process is a method of softening hard water. In this method, the soluble calcium and magnesium salts in water are chemically converted in to insoluble compounds, by adding calculated amount of lime and soda. Sodalime glass process sodalime glass is divided technically into as follows 1glass used for windows, called flat glass, and 2glass for containers, called container glass.
1417 488 903 1477 752 627 1147 65 1680 1591 473 1400 636 1384 1491 341 1518 128 537 1019 652 1304 194 49 500 1440 1189 137 107 708 744 1287 1464