The article describes common cleaning processes, including alkaline, electrolytic, solvent, emulsion, molten salt bath, ultrasonic and acid cleaning as well as pickling and abrasive blasting. Cryolite a fluoride salt is used as a solvent for aluminium oxide in the production of aluminium in the hallheroult process. Molten salt cleaning processes find broad applications in the cleaning of used engine. The inspiration is the work the united states oak ridge national laboratory ornl did by building and operating 2 successful molten salt reactors nuclear reactors in 1954 the are and the 1960s the msre. No part of this book may be reproduced, stored in a retrieval system, or trans. Experimental methods the molten salt mixtures were prepared from nano 3, kno 3, lino 3 and cano 3 2tetrahydrate reagent grade salts sigmaaldrich co. Cyanide and chloride salt mixtures are used for surface modification of alloys such as carburizing and nitrocarburizing of steel. Viscosity was measured over the temperature range from near the relatively. Williams oak ridge national laboratory lockheed marietta energy research corp. Moltensalt thermocline tanks are a lowcost option for thermal energy storage in concentrating solar power csp systems.
Phase composition of cathodic deposits synthesized in flinakk2taf7kbf4 melt. Laboratory of molten salts institute of high temperature. To melt small quantities of the nitrate mixtures for observations of solidification. A molten salt reactor msr is a type of nuclear reactor that uses liquid fuel instead of the solid fuel rods used in conventional nuclear reactors. Based on the analyses performed on various residual stress profiles in ion. Contents page foreword iii preface iv acknowledgments iv 1. Table salt is a combination of sodium and chlorine, which form ionic bonds. Benefits of heat treatment in salt baths compositions of salt baths. Box 2008 oak ridge, tennessee 3783 16224 423 5745769 abstract wise. Smirnov, ussr state prize winner, honored scientist of the. Compositional and bath temperature effects on heat.
It utilizes an extractive distillation column with a mixture of zirconium and hafnium tetrachlorides introduced into a distillation column having a top and bottom with hafnium enriched overheads taken from the top of the column and a molten salt solvent circulated through the column to provide a. This experience is often cited as an argument for the use of these salts in largescale solar energy systems. Morton water is softer, purer, more refreshing water that just feels better. A work part immersed into a molten salt is heated by heat transferred by. When parts are immersed in the molten salt, heat is transferred by direct contact to the surface. Jul 09, 2015 a novel method to identify the composition of salt mixtures featuring a decreased melting temperature is presented at the end of this section. I even put clay coated blades down in the salt, but i put them in the oven at 400500 degrees for 12 hours to first make sure theyre dry. This itself is not a radical departure when the fuel is solid and fixed. Welcome to the molten salt energy technologies web site.
Optical and chemical properties of molten salt mixtures. Molten nitrate salt development for thermal energy storage. They are quite distinct from other molten salt compositions that are used for simple heat transfer or heat treatment applications. Regarding the arrangement of basic elements, the positive. Molten salt reactors msrs use molten fluoride salts as primary coolant, at low pressure. With softer water, you can enjoy a more welcoming home. Jul 19, 2004 a novel solar process and reactor for thermochemical conversion of biomass to synthesis gas is described. During these processes, nitrogen, carbon, and small amounts of oxygen are diffused into the surface of the steel, creating an epsilon iron nitride layer. In imperial or us customary measurement system, the density is equal to 96. The flux cover used in the wet process is composed of zinc ammonium chloride.
Special attention is devoted to the surface treatment of steel workpieces. Buy now see all 3 formats and editions hide other formats and editions. Molten salt oxidation the national academies press. Key words molten salts, eutectic mixture, thermal storage, thermal stability, solar thermal collectors. The furnace contains salt such as nitrates, nitrites, caustic soda, chlorides, carbonates, and cyanide. Discussion 2 lithiumfluoride 2 sodiumfluoride 3 potassiumfluoride 3 cesiumfluoride 3 berylliumfluoride 3 magnesiumfluoride,calciumfluoride,strontium fluoride,bariumfluoride,lanthanumiifluoride, andceriumiiifluoride 4 thoriumivfluorideanduranium. While discussing about application of molten salts in heat treatment. Thermal energy storage overview and specific insight into.
This chapter describes the implementation of those techniques briefly. This book was prepared as an account of vvork sponsored by an agency of the unhed. When choosing the composition of a salt for metal heat treatment, it is necessary to consider the corrosion activities of the molten salts in relation to the metal being heat treated. Compositional and bath temperature effects on heat transfer. Incoloy800h in the lifnafkf molten salt with air the most stable corrosion product phases were calculated based on the change of gibbs energy of various possible reactions in the corrosion process all the possible corrosion products have been considered in. Corrosion in very hightemperature molten salt for next. The composition of these baths and their operating temperature.
Msrs offer multiple advantages over conventional nuclear power plants, although for historical reasons they have not been deployed. Salt bath heat treatment and equipment steel heat treating. Our position as an integrated process supplier allows us to optimize the relationship between process chemistry and process equipment. Review of moltensalt thermocline tank modeling for solar. A mixture of sodium nitrate nano 3 and potassium nitrate kno 3 in equal quantities is used for the molten baths preparation. Composition of molten nano 3 kno 3 mixture and bath temperature used for.
System with novel molten salt december 8, 2011 april 30, 20 matthieu jonemann halotechnics, inc. Zinc zn and pb can then selectively electrowon from the solution, and the residue can be recycled back to eaf. Thermal energy storage overview and specific insight. Since the parts are immersed in the salt bath, air cannot contact the work piece and. The total salt requiring disposal would be several times the weight of the chemical agent destroyed. Using molten salt as a heat transfer fluid can deliver significant advantages over alternatives such as mineral oil. A molten salt reactor msr is a class of nuclear fission reactor in which the primary nuclear reactor coolant andor the fuel is a molten salt mixture. Any moisture introduced into molten salt will immediately evaporate and need somewhere to escape to. Water that is softer on your skin and clothes, while making cleaning easier. Melting point of such eutectic composition is about 485. Heat transfer salt for high temperature steam generation disc 5. Molten salt bath cleaning surface engineering handbooks asm.
Pdf compositional and bath temperature effects on heat. Salt bath heat treatmentis a heat treatmentprocess comprising an immersion of the treated part into a molten salt or salts mixture. Thermal evaluation of molten salts for solar thermal energy. Industrial use of molten nitratenitrite salts technical. In the wet galvanizing process, the workpiece is not fluxed and dried prior to immersion in the molten zinc bath.
Structure and properties of tantalum borides obtained by molten salt. A pilot facility for trough plants is due to come online this year, however, a number of challenges remain. Salt bath thermal treating and nitriding request pdf. There can challenges with all of these system types. Harin ullal and craig turchi subcontract report nrelsr520058595 may 20. The concept is based on dispersion of biomass particles in a molten inorganic salt medium and, simultaneously, absorbing, storing and transferring solar energy needed to perform pyrolysis reactions in the hightemperature liquid phase. It involves dissolving aluminium oxide alumina obtained most often from bauxite, aluminiums chief ore, through the bayer process in molten cryolite, and electrolysing the molten salt bath, typically in a purposebuilt cell.
There is no compelling economic advantage to using molten salt in a trough solar field for a system without thermal storage there appears to be significant economic advantages for a molten salt htf with storage. The development status of molten salt breeder reactors 1972. Ions are formed by atoms gaining or losing electrons, which causes the atoms to be positively or negatively charged. Advances in molten slags, fluxes, and salts wiley online. Typical operating temperatures of the molten salt baths are 550650. The laboratory of molten salts is one of the oldest chemistry laboratories in the ural branch of the russian academy of sciences. Molten salt techniques has been added to your cart add to cart. Overview on use of a molten salt htf in a trough solar. In order to design large production facilities, accurate physical and thermodynamic properties of molten salts must be known.
A certain fraction of the molten salt bath must be removed and fresh sodium carbonate added to maintain desirable salt composition. Salt bath hardening can offer advantages over alternative hardening and tempering methods. Fast solution heat treatment may be achieved by heating an aluminum alloy part in a molten salt bath. The molten salt selection and characterization was the objective of this thesis. Molten nitrate salt development for thermal energy storage in. Molten salts are being employed throughout the world as heat transfer fluids and phase change materials for concentrated solar power csp production and storage. The proposed method required knowledge of the residual stress profiles, the molten salt bath s temperature and soaking time, and the bath s composition. Molten chloride salt mixtures are commonly used as baths for various alloy heat treatments, such as annealing and martempering of steel. Molten salt is often considered the ideal heat treating medium. It also explains how their ability to dissolve many inorganic compounds such as oxides, nitrides, carbides and other. From the 1949 to 1988, the laboratory was supervised by m. Handbook comitee, asm hand book volume 4 heat treating. Encyclopedia of iron, steel, and their alloys, chapter.
The melt is variously claimed to provide heat capacity, to be a carrier of. Advanced thermal storage system with novel molten salt. The ability of a molten salt bath to supply heat at a rapid rate. Molten salt reactors and thorium energy 1st edition. Molten salts process heating systems sigma thermal. It also explains how to select the appropriate process for a given soil type and surface composition. Siegel sandia national laboratories, po box 969 livermore, ca 94551, usa and sandia national laboratories, po box 5800 albuquerque, new mexico 87185, usa abstract.
A salt bath furnace is basically a ceramic or metal container filled with molten salt into which work is immersed for either heating or cooling. This patent describes an improvement in a process for zirconiumhafnium separation. Kolene has been engineering molten salt bath equipment for nearly 75 years. From lab to applications examines how the electrical and thermal properties of molten salts, and generally low vapour pressure are well adapted to high temperature chemistry, enabling fast reaction rates. The light attenuation coefficient of two reagent grade molten salt mixtures kno 3 nano 3, 40 60 wt% and nacikci, 5050 wt% was measured and characterized over the wavelength range 400nm 800nm and for different operating temperature ranges. Msrs offer multiple advantages over conventional nuclear power plants, although for historical reasons they have not been deployed the concept was first established in the 1950s. Overview on use of a molten salt htf in a trough solar field. There is growing awareness that nuclear energy is needed to complement intermittent energy sources and to avoid pollution from fossil fuels.
Industrial use of molten nitratenitrite salts osti. Additionally limitations of molten salt storage may arise due to storage media costs, the risk of corrosion and the difficulty in hygroscopic salt handling. Essential readings in light metals wiley online books. The major fundamental topics covered at this asi were the structure of melts, thermodynamics of molten salt mixtures, theoretical and experimental studies of transport processes, metalmetal salt solutions, solvent properties of melt systems, acidbase effects in molten salt chemistry, electronic absorption, vibrational, and nuclear magnetic. The simplest example of a molten salt would be to heat sodium chloride table salt to a red heat greater than 801 c, or 1474 f1 upon which it. Molten salt extractive distillation process for zirconium. The composition of these baths and their operating temperature in the range 1472.
I clean my blades very carefully and make sure they are dry. It is directly immersed in a molten bath of zinc containing a blanket of flux on the surface of zinc. Their temperature varies from 290 to 550 c when the solar field is operating. Characterization of the molten salt reactor experiment fuel and flush salts david f. F are the two factors which determine the depth and nature of the case.
In most molten salt energy storage systems, the molten salt is maintained as a liquid throughout. Molten salt reactors is a comprehensive reference on the status of molten salt reactor msr research and thorium fuel utilization. There are three primary types of molten salt heating systems. Molten nitrate salt development for thermal energy storage in parabolic trough solar power systems robert w. By rajesh chhabara molten salts can handle temperatures of up to 550. In imperial or us customary measurement system, the. Density of molten salt in 285 units and reference information. Surface cleaning metals handbook desk edition, 2nd ed. Hardening, carburizing, and nitrocarburizing of steel are heat treatment processes usually carried out in baths of molten salts. These processes are categorized as molten salt bath ferritic nitrocarburizing. As an example, the mechanism of fused salt nitriding is examined. As with entrained flow gasifiers, in molten bath processes the coal and gasifying agent flow cocurrently into the reactor, but in the latter they intimately contact a molten pool of slag, metal e.
349 344 41 27 1326 1450 1121 870 219 860 1058 389 1259 509 1386 281 907 150 576 781 326 322 295 257 1440 1556 570 234 1372 624 1268 1365 1169 375 1270