DOCSLIB.ORG

Chapter 10 Cryogenics Chapter 10. Cryogenics

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Chapter 10 Cryogenics Chapter 10. Cryogenics Chapter 10. Cryogenics Introduction Materials properties Refrigeration Insulation Cryostat design Cryogenic systems dolan swip 2009 1 Introduction "cryo"= cold "genes" = that which generates 1877-90 liquefaction of N2, O2 1892-98 Dewar invented vacuum flask liquified H2 1908-11 H.K. Onnes liquefied He, discovered superconductivity 1934 Kapitza He liquefaction engine 1947 S.C. Collins liquefaction process dolan swip 2009 2 Applications of Cryogenics Industrial gas production Food preservation Biomedical applications Bearings Elec tron ics Motors and generators Physics research Space technology Fusion research Magnets Neutral beams Vacuum pumps dolan swip 2009 3 Mechanical Properties Percent Elongation Mechanical ductility yield stress modulus of elasticity fa tigue life Failure of welds at low T. “Ductile-to-brittle Transition temperature” dolan swip 2009 4 Thermal Properties Specific heat (J/mole-K): R = 8. 314 J/mole-K D = Debye Temperature D At T < 0 . 08 D, 3 C = 233.8 (T/ D) Sta in less s tee l T(K) C (J/kg-K) 293 476 77 159 20 4.6 dolan swip 2009 5 Thermal Properties T Enthalpy h = ho + dT C(T) 0 Heat added per kg to raise temperature: T2 W/M = dT C(T) = h2 –h1 T1 ElExample: A co il con ta ins 100 tonnes of C u st abili zer. If the coil energy of 0.9 GJ is dissipated by a quench, By how much does the Cu temperature rise from 4 K? h = 0.9x109 J/105 kg = 9000 J/kg = 9 J/g Interpolating in Table, we find T = 93 K. dolan swip 2009 6 Enthalpy vs. Temperature dolan swip 2009 7 Thermal Conductivity structural supports coil outside: didesire low k Strength /k relative to SS -304 dolan swip 2009 8 Thermal Expansion Example: SS-304, 4 K 300 K L/L ≈ 0.00303 Need to compute thermal stresses. dolan swip 2009 9 Thermal Emissivity Used for radiant heat 293 K transfer in cryostats dolan swip 2009 10 Electrical Resistivity DdDepends on purity B & radiation damage dolan swip 2009 11 Vapor Pressures of Fluids From H. Neumann, FZK Summer School, 2008 dolan swip 2009 12 Cryogenic Liquids Cannot be liquefied above “critical temperature”. How separate O2 from N2 ? dolan swip 2009 13 Refrigeration and Liquefaction Joule-Thomson Effect: If TT T<Tinversion, then expansion cooling Tinv(H2) = 204 K Tinv(He) = 20 K require precooling dolan swip 2009 14 Expansion Engines Ordinary expansion raises entropy, wastes energy Slow expansion into engine (piston or turbine) cooling with less entropy rise, more efficient. dolan swip 2009 15 Collins Refrigeration System 25% 29K 50% 8K 25% 12% dolan swip 2009 16 Insulation dolan swip 2009 17 Heat Conduction Example dolan swip 2009 18 Convection and Radiation Small cells (styrofoam) or vacuum convection RditiRadiation Stephen-Boltzmann Constant: = 5.67x10-8 W/m2K4 Multilayer radiation barriers: 10 shields with e = 0.20 Prad = 0.003 as large Prad ≈ kapp A(T2-T1)/L dolan swip 2009 19 Apparent Mean Thermal Conductivity 300K 77K Optimum spacing ~ 1 layer/mm Compaction kapp dolan swip 2009 20 Vapor Shielding 293 K 77 K vapor LHe, 4.2 K LN2 dolan swip 2009 21 Cryostat Design 77 K Support JxB and gravity forces, low heat leak Styrofoam 77K 293 K dolan swip 2009 22 Heat Inflows 16 TF coils Bmax = 12 T = dolan swip 2009 23 Superinsulation Installation Poor Better Best From H. Neumann, FZK Summer School, 2008 dolan swip 2009 24 Liquid Nitrogen Storage Dewar From H. Neumann, FZK Summer School, 2008 dolan swip 2009 25 MFTF-B Cryogenic System During quench 10 m3 LHe 7000 m3 gas recovery bags. dolan swip 2009 26 MFTF-B Cryogenic System 7 struts Diameter =27cm Thickness =2.9cm Each ~ 8 W dolan swip 2009 27 MFTF-B Cryogenic Systems Thermal stress limits cooling rate: 80K4K takes ~ 4-5 days. dolan swip 2009 28 Summary Cryogenic systems have many applications (industrial, food, biomedical, mechanical, electrical, physics, space, fusion). Materials properties at low T limit performance (mechanical, thermal, electrical) . Refrigeration technology well developed, but expensive. About 300 W input power per W of heat removed at 4 K. Multilayer aluminized plastic films in vacuum low kapp Structure dominates heat inflow. dolan swip 2009 29 dolan swip 2009 30.
Load more

Recommended publications
  • VACUUM RECOVERY of ASPHALT EMULSION RESIDUE (An Arizona Method)
    ARIZ 504 July 1980 (3 Pages) VACUUM RECOVERY OF ASPHALT EMULSION RESIDUE (An Arizona Method) Scope (d) No. 10 sieve conforming to AASHTO designation M 92. I. This method describes a low temperature vacuum procedure for recovery of the asphalt residue (e) Vacuum recovery apparatus as shown from asphalt emulsions. It is is not suitable for assembled in Fig. I. quantitative recovery of solvents from emulsions I) Vacuum source capable of producing an containing low boiling range distillates. absolute vacuum within the system of approximately 710 mm (28 in.) mercury. Apparatus 2) Thermometer - shall have a range of _5° to 1. The apparatus shall consist of the following: +200°C (23°F to 392°F). The overall length (a) Brass stirring rod. shall be 600 mm (24 in.) and the distance from the bottom of the bulb to the zero point (b) 8 oz. ointment can. shall be 300 mm (12 in.) (c) 100 ml. stainless steel beaker. 3) Stirrer hot plate. VACUUM RECOVERY APPARATUS 300 mm Allihn condenser H20 Out / Thermometer Vacuum Release Pinch Clamp 500 m. 1,000 ml. Filtration Flask Filtration Flask Teflon Stirring Bar H20 In 500 ml. Filtration Flask Portable Heat Gun FIGURE I ARIZ 504 July 1980 4) Teflon covered stirring bar. (g) Insert the stoppered themometer (positioned 5) 1000 ml. and two 500 ml. filtering flasks with in the stopper at an angle to prevent contact with tubulation. stirring bar) into the flask and set on hot plate at a medium high heat setting (#4). The bulb of the 6) 300 mm Allihn condensor.
    [Show full text]
  • Temperature Distribution in a Vacuum Flask
    Solved with COMSOL Multiphysics 5.0 Temperature Distribution in a Vacuum Flask Introduction The following example solves for the temperature distribution within a vacuum flask holding hot coffee. The main interest here is to illustrate how to use MATLAB® functions to define material properties and boundary condition directly within the COMSOL model. Two MATLAB functions are used to define the temperature dependent thermal conductivity of the vacuum flask shell and the insulation foam, while a third function defines the heat transfer coefficient that corresponds to a natural convective cooling for a vertical plate and surrounding air. Model Definition Assume axial symmetry for this simulation to reduce the model geometry to the 2D cross-section of the vacuum flask geometry shown in Figure 1. The vacuum flask consists of a steel shell isolated with a foam material, and a cork made of nylon. On the inside wall apply a constant temperature, assuming that the vacuum flask is filled with coffee of constant temperature. 1 | TEMPERATURE DISTRIBUTION IN A VACUUM FLASK Solved with COMSOL Multiphysics 5.0 Nylon cork Air Steel shell Constant temperature Insulation foam Figure 1: Cross section of the vacuum flask geometry Define the temperature dependent thermal conductivity of steel according to the following polynomial expression: –4 2 –8 3 ksteel = 71.12– 0.115T + 1.16e T – 4.25e T As shown in Figure 2, in the temperature interval of interest for the model, the thermal conductivity decreases with increasing temperature. 2 | TEMPERATURE DISTRIBUTION IN A VACUUM FLASK Solved with COMSOL Multiphysics 5.0 Figure 2: Thermal conductivity of the steel wall versus temperature.
    [Show full text]
  • Liquefaction, Storage and Transfer of Cryofluids
    Storage and transfer of cryofluids Christian Gianese www.neel.cnrs.fr Guilty 1: Arsène d’Arsonval (1851 - 1940) He invented a glass container with double wall, the vacuum being done in the space between the outer and inner walls: the vase d'Arsonval. About 1902, he collaborated with Georges Claude on the liquefaction of gases and inspires industries Air Liquid. www.neel.cnrs.fr Guilty 2: James Dewar (1842 - 1923) He discovered a process to produce liquid oxygen in 1891 and liquid hydrogen in 1898, in industrial quantities. He developed an insulating bottle, the Dewar flask, still named after him, to study low temperature gas phenomena. In fact, he improves the d’Arsonval vessel by depositing a layer of silver on the inside wall, to minimize the heat input by radiation. He also used this bottle to transport liquid gases such as hydrogen. In 1905, he observed that cold charcoal could produce a vacuum. www.neel.cnrs.fr Thermos The first vacuum flasks for commercial use were made in 1904 when a german company, Thermos GmbH, was formed. Thermos, their tradename for their flasks, remains a registered trademark in some countries but was declared a genericized in the US in 1963 as it is colloquially synonymous with vacuum flasks in general; in fact it is far more common to speak of a domestic thermos than a vacuum flask. www.neel.cnrs.fr STORAGE www.neel.cnrs.fr The most important factors in storage systems Logistics Volume of storage, dimensions, transport, etc Reliability, safety Economics ! Rate of evaporation of cryogenic liquids (helium:
    [Show full text]
  • Organic Chemistry Ii
    University of Maribor Faculty of Chemistry and Chemical Engineering Laboratory for Organic and Polymer Chemistry and Technology Laboratory Course ORGANIC CHEMISTRY II Muzafera Paljevac and Peter Krajnc Proofreader: Dr. Victor Kennedy 1. THE LIST OF LABORATORY EXPERIMENTS IN ORGANIC CHEMISTRY II LAB COURSE 1. Determination of melting point 2. Continuous (fractional) distillation 3. Distillation with water steam 4. Recrystallization, Sublimation 5. Paper and thin layer chromatography _____________________________________________________________________________________ 6. Synthesis of acetylsalicylic acid 7. Synthesis of tert-butyl chloride 8. Synthesis of methyl orange 9. Synthesis of aniline 10. Synthesis of ethyl acetate 11. Synthesis of ethyl iodide 1 2. LABORATORY RULES AND REGULATIONS - You must wear a lab coat at all times when working in the laboratory. You are expected to provide your own lab coat, and you will not be allowed to work in the lab without one. - Safety glasses and gloves will be supplied when required and must be worn where notices, experimental instructions or supervisors say so. - Long hair must be tied back when using open flames. - Eating and drinking are strictly prohibited in the laboratory. - Coats, backpacks, etc., should not be left on the lab benches and stools. There are coat racks just outside the lab. Be aware that lab chemicals can destroy personal possessions. - Always wash your hands before leaving the lab. - Notify the instructor immediately in case of an accident. - Before leaving the laboratory, ensure that gas lines and water faucets are shut off. - Consider all chemicals to be hazardous, and minimize your exposure to them. Never taste chemicals; do not inhale the vapors of volatile chemicals or the dust of finely divided solids, and prevent contact between chemicals and your skin, eyes and clothing.
    [Show full text]
  • Simple Calorimeter for Heats of Fusion. Data on The
    U.S. Department of Commerce, Bureau of Standards RESEARCH PAPER RP607 Part of Bureau of Standards Journal of Research, Vol. 11, October 1933 A SIMPLE CALORIMETER FOR HEATS OF FUSION. DATA ON THE FUSION OF PSEUDOCUMENE, MESITYLENE (« AND 0), HEMIMELLITENE, o- AND m-XYLENE, AND ON TWO TRANSITIONS OF HEMIMELLITENE By Frederick D. Rossini abstract A vacuum flask with a thermoelement serves as a simple calorimeter for measuring heats of fusion quickly and economically, with an accuracy of a few percent. The following heats of fusion (with estimated uncertainties), in k-cal. per mole, were obtained: pseudocumene, — 44.1° C, 2.75±0.06; hemimelli- tene,-25.5° C, 2.00±0.05; mesitylene (a), — 44.8° C, 2.28±0.06; mesitylene (0), -51.7° C., 1.91±0.05; o-xylene,-25.3° C, 3.33±0.07; m-xylene,-47.9° C, 2.76 ±0.05. Hemimellitene was found to have two transitions below the freez- ing point, with the following heats of transition, in A>cal. per mole: hemimelli- tene (7-»0),-58±2° C.,0.28±0.04; hemimellitene (P^a),- 46 ± 1° C.,0.36±0.04. CONTENTS Page I. Introduction 553 II. Apparatus and method 553 III. Materials 554 IV. Standardization experiments 555 V. Experimental data 557 VI. Conclusion 559 I. INTRODUCTION The simple calorimeter described here was assembled in order to provide a means for measuring as quickly and economically as prac- ticable, and with an accuracy of a few percent, the heats of fusion of certain hydrocarbons for which there are no data.
    [Show full text]
  • APR PET S-12 Dissolution Screening
    PET Dissolution Test Document Code – PET-S-12 Publication or Revision Date: November 16, 2018 Introduction – Scope, Significance and Use This protocol is derived from a copyrighted method owned by M&G Polymers USA LLC and international copyright treaties protect the method. In consideration for the use of this method, users agree to hold APR and M&G Polymers USA LLC and its affiliated companies harmless and not be liable for any incidental, consequential or other indirect damages resulting from the use of this method. Disclaimer: This document has been prepared by the Association of Plastic Recyclers as a service to the plastic industry to promote the most efficient use of the nation’s plastic recycling infrastructure and to enhance the quality and quantity of recycled postconsumer plastic. The information in this document is offered without warranty of any kind, either expressed or implied, including WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, which are expressly disclaimed. APR and its members accept no responsibility for any harm or damages arising from the use of or reliance upon this information by any party. Participation in the Recognition Program is purely voluntary and does not guarantee compliance with any U.S. law or regulation or that a package or plastic article incorporating the innovation is recyclable or will be recycled. Equipment/Supplies List • Heat resistant gloves • Apron; full length that covers torso, arms and legs • Faceshield (hood sash if available) • Metal beaker with handle, at least 700 ml capacity • Fiberglass matting for setting hot beaker on while heating and cooling • Thermometer with metal armor casing • Safety glasses • Vented Hood • Hot Plate • 1000 ml filtering flask • Buchner funnel • Filter Paper (Whatman #1, 11 micron, VWR Catalog #28450-128) ©2018 Association of Plastic Recyclers.
    [Show full text]
  • Mycoplasma Screening of Cultured Cells by Fluorescence Microscopy
    Mycoplasma Screening of Cultured Cells by Fluorescence Microscopy Prepare cell samples Make sure cells have been passages at least 2 times after a thaw so mycoplasma have recovery time from their time in cold storage!! 1. With sterile tweezers or Pasteur pipet attached to vacuum flask place one 22x22mm or 25mm round sterile glass coverslip into well of sterile 6well plate (# wells = # cell lines tested) or 35mm dish. 2. Add 3 ml of (cell line specific) complete medium without antibiotics (important because they may inhibit mycoplasma and produce a false negative) slowly to the well (touch first drop of medium to the edge of the coverslip until capillary action carries the liquid under the coverslip and completely covers the underside, which holds the coverslip to the dish and disallows cell growth on the underside). 3. Add 2-4 drops of cell suspension (approximately 10^5cells) to the medium in the well. Rock gently. (Note: For testing non-adherent cells, a negative indicator line must be used. The line to be tested must be coplated with the indicator line. Mycoplasma will transfer to the indicator line within 2 days and will be visualized.) 4. Incubate 2-3 days at appropriate temperature for cell line until they are approximately 70% confluent (mycoplasma live on the outer membrane, and thus are easier to visualize when cells are subconfluent). To Fix 1. Add 3 ml methanol gently to the side of the dish (do not remove growth medium). 2. Leave for 3 min at room temperature. 3. Aspirate methanol/medium solution. 4. Add 3 ml methanol for 15 min at room temperature.
    [Show full text]
  • Edna PROTOCOL SAMPLE COLLECTION
    eDNA PROTOCOL SAMPLE COLLECTION Caren Goldberg and Katherine Strickler, Washington State University September 2014 Adapted from Protocol Version 04/12/2012 (D.S. Pilliod, R.S. Arkle, and M.B. Laramie) USGS Snake River Field Station MATERIALS 1. Cellulose nitrate disposable filter funnels or other field-tested, disposable filter funnels 2. Vacuum flask (1L) 3. Silicone tubing 4. Vacuum hand pump (from auto parts store) 5. Rubber stopper with hole for funnel stem 6. Latex or nitrile gloves (non-powdered) 7. Forceps (filter forceps if possible) 8. High quality, o-ring screw cap 2mL tubes (e.g., Sarstedt brand) with 1mL 100% molecular-grade ethanol (not denatured) 9. Ethanol-proof laboratory pen (do not use a regular Sharpie marker) 10. 50 mL tubes of 30 mL 1) 50% household bleach solution 2) distilled water in a holder (a foam drink holder [koozie] works well) 11. Polypropylene grab bottles and cooler (for off-site filtering) or Whirl-Pak® bags (for on- site filtering) 12. Water, bleach, scrub brush, and tubs (for decontaminating between sites) 2 3 5 1 4 2 Figure 1. Filter funnel (1), vacuum flask (2), silicone tubing (3), vacuum pump (4), and rubber stopper (5). 9 7 10 8 6 1 Figure 2. Latex or nitrile gloves (6), forceps (7), 2 mL tubes with 1 mL ethanol (8), ethanol-proof lab marker (9), and 2 50 mL tubes with 50% household bleach solution distilled water (10). 3 11a 11b Figure 3. Polypropylene grab bottles (11a) and Whirl-Pak® bag (11b). 12a 12d 12b 12c Figure 4. Water (12a), bleach (12b), scrub brushes (12c), and tubs (12d) for decontaminating boots and equipment between sites.
    [Show full text]
  • Forms of Energy
    Plot 48 Muwayire Rd (behind IHK Hospital) P.O.BOX 5337, KAMPALA - UGANDA Tel: 256783111908 Email: [email protected] Website: www.stagnes.co.ug FORMS OF ENERGY Energy is the body’s ability to do work Matter Matter is anything that has mass and volume OR anything that has weight and occupies space The meaning of each of the following a. Mass: is a quantity of matter in an object. b. Volume: Is the space occupied by an object. c. Molecules: It is the smallest particles of matter. d. Weight: is the gravitational force exerted on an object by the earth. States of matter There are three different states of matter - Solids - Liquids - Gases Solids Examples of solids. - Wood - Rubber - Glass - Plastic Characteristics of solids. - Molecules are closely packed. - Particles are held together very tightly. 1 - Molecules do not move from position but vibrate. - Solids have shape, size and volume apart from irregular objects. Diagram to show the arrangement of molecules. Liquids Examples of liquids. - Water - Soda - Oils - Juice Characteristics of liquids. - Molecules are spaced. - Molecules loosely held together. - Liquids have a proper volume (capacity) - Liquids have no definite shape (take up the shape of the container in which they are poured) Diagram to show the arrangement of molecules. Gases Examples of gases. - Nitrogen - Carbon dioxide - Oxygen 2 - Rare gases Characteristics of gases. - Molecules are far apart - Gases have no definite shape - Gases have a particular volume. - Molecules move freely. Diagram to show the arrangement of molecules. ACTIVITY 1. What is energy? 2. What is matter? 3. Name the three states of matter.
    [Show full text]
  • Basic Cell Culture Techniques
    BASIC CELL CULTURE TECHNIQUES STERILE TECHNIQUES Aseptic or sterile technique is the execution of tissue culture procedures without introducing contaminating microorganisms from the environment. In doing tissue culture work, 70% of the problems are due to a lack of good sterile technique. Microorganisms causing the contamination problems exist everywhere, on the surface of all objects and in the air. A conscious effort must be made to keep them out of a sterile environment. Because many and sometimes awkward manipulations are required for various techniques, tissue culture media used are often supplemented with antibiotics. Antibiotics do not eliminate problems of gross contamination which result from poor sterile technique or antibiotic- resistant mutants. Autoclaving renders pipettes, glassware, and solutions sterile. Nutrient medium cannot be autoclaved. The compounds in nutrient medium are destroyed by the heat of autoclaving. Medium must therefore be sterilized by passing it through a sterile filter small enough in pore size to hold back bacteria and mycoplasmas (Millipore Sterivex - GS 0.22u disposable filter units). Here are some rules of thumb to follow to keep your medium, cultures, and glassware from becoming contaminated: 1. Wipe your work area and hands with 70% ethanol before starting. Spray any container you plan to put into the sterile workspace with 70% ethanol. 2. Never uncover a sterile flask, bottle, petri dish, etc., until the instant you are ready to use it. Return the cover as soon as you are finished. Never leave it open to the environment. 3. Sterile pipettes should never be taken from the wrapper until they are to be used.
    [Show full text]
  • Structure & Working
    Vacuum Flask or Thermos is an insulating storage vessel that greatly lengthens the time over which its contents remain hotter or cooler than the flask's surroundings. Instead of containing any kind of heating or cooling element, so as to keep hot things hot and cold things cold a thermos is designed to in a such a way that it minimizes transfer of heat by not allowing heat to escape or enter easily. Heat can be transferred through the air. To keep heat from escaping, you need insulation. The best insulator possible is a vacuum, where there is no air. Structure & Working Additional insulation Screw-on stopper reduces heat losses and Outer plastic or stainless steel case. cushions flask against impacts. Outer layer of glass coated with reflective material (or stainless steel in unbreakable flasks). Vaccum Inner layer of glass (or stainless steel in unbreakable flasks). One or more supports keep inner vacuum container in place. (A)The thermos consists of two flasks, placed one within the other and joined at the neck. The gap between the two flasks is partially evacuated of air during its construction and this creates a near-vacuum which significantly reduces heat transfer by conduction or convection (B).The outer casing of a thermos flask is made up of plastic or metal. Plastic, being a poor conductor of heat, acts as an insulator preventing the heat loss through conduction. (C).Inside it, is a double-walled container made of glass or stainless steel. Both the walls are polished so they are shiny. The space between the two walls is a vacuum; this prevents heat loss through convection since there are no air particles to carry out the transfer of heat.
    [Show full text]
  • Rupture of Glass Vacuum Flask
    Accident Report: Rupture of Vacuum Flask Accident Description A graduate student was attempting to vacuum distill 4-methylanisole (STP boiling point: 174 OC) at room temperature, and was using liquid nitrogen to condense the anisole into a receiving flask. After some time had elapsed, he observed that no anisole had been transferred to the receiving flask, indicating a possible problem with the setup. He checked the reading on the gauge which indicated that the flask was under a partial vacuum, as expected. He dismantled the setup and removed the receiving flask. Ice had formed around the flask. Seeking to verify what was in the flask, he rinsed it off with cold tap water at a sink. He observed a cloud form in the flask. A few seconds later, the flask shattered, and he was struck in the face, neck, hands and chest by shards of glass. There was no chemical exposure. Fortunately, he was wearing safety eyewear and so did not receive any injuries to his eyes. Two other people were present in the lab at the time who immediately called 9-911 and requested medical assistance. Fortunately his injuries were not life-threatening. However, he lost a significant amount of blood during the time which elapsed between the accident and the arrival of the paramedics. The student had to have approximately 30 stitches to his face and neck area. Vacuum rack where flask was manipulated before warming at sink Conclusions and Recommendations 1. We suspect a crack or leak in the flask caused the explosion. When a flask partly open to the atmosphere is immersed in liquid nitrogen, air is condensed.
    [Show full text]