Advertisement
| cascade tower fan manual: Practical Manual of Chemical Plant Equipment Robert G. Schmidt (P.E.), 1967 |
| cascade tower fan manual: Design Manual for Small Steam Turbines Gerald R. Guinn, 1990 |
| cascade tower fan manual: The Coding Manual for Qualitative Researchers Johnny Saldana, 2009-02-19 The Coding Manual for Qualitative Researchers is unique in providing, in one volume, an in-depth guide to each of the multiple approaches available for coding qualitative data. In total, 29 different approaches to coding are covered, ranging in complexity from beginner to advanced level and covering the full range of types of qualitative data from interview transcripts to field notes. For each approach profiled, Johnny Saldaña discusses the method’s origins in the professional literature, a description of the method, recommendations for practical applications, and a clearly illustrated example. |
| cascade tower fan manual: Capital and Operating Costs of Pollution Control Equipment Modules: Data manual, by Herbert G. Blecker and Thomas M. Nichols Theodore W. Cadman, Thomas M. Nichols, 1973 |
| cascade tower fan manual: Pulp & Paper Canada Reference Manual & Buyers' Guide , 1977 |
| cascade tower fan manual: Capital and Operating Costs of Pollution Control Equipment Modules: Data manual, by Herbert G. Blecker and Thomas M. Nichols , 1973 |
| cascade tower fan manual: Moody's Manual of Investments John Sherman Porter, 1922 American government securities); 1928-53 in 5 annual vols.:[v.1] Railroad securities (1952-53. Transportation); [v.2] Industrial securities; [v.3] Public utility securities; [v.4] Government securities (1928-54); [v.5] Banks, insurance companies, investment trusts, real estate, finance and credit companies (1928-54). |
| cascade tower fan manual: Pulp & Paper Magazine of Canada Reference Manual & Buyers' Guide , 1973 |
| cascade tower fan manual: Pulp and Paper Manual of Canada , 1972 |
| cascade tower fan manual: Operation and Maintenance Manual for Electrostatic Precipitators , 1985 |
| cascade tower fan manual: The Turbine Pilot's Flight Manual Gregory N. Brown, Mark J. Holt, 2001-03 Covering all the essentials of turbine aircraft, this guide will prepare readers for a turbine aircraft interview, commuter ground school, or a new jet job. |
| cascade tower fan manual: Monthly Catalogue, United States Public Documents , 1992-11 |
| cascade tower fan manual: Catalogue of Publications Issued by the Government of the United States United States. Superintendent of Documents, 1975-06 February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index |
| cascade tower fan manual: Air Pollution Engineering Manual Air & Waste Management Association, 1992 THE AIR & WASTE MANAGEMENT ASSOCIATION is the world's leading membership organization for environmental professionals. The Association enhances the knowledge and competency of environmental professionals by providing a neutral forum for technology exchange, professional development, networking opportunities, public education, and outreach events. The Air & Waste Management Association promotes global environmental responsibility and increases the effectiveness of organizations and individuals in making critical decisions that benefit society. |
| cascade tower fan manual: Control Systems for Heating, Ventilating and Air Conditioning R. Haines, 2012-12-06 There are two reasons why we have a new edition every four or five years. The first is that technology changes. Chapter 10, on computer-based con trols, has had to be almost completely rewritten. Fundamentals don't change, but the tools available to us do change. Evaluation and proper use of those tools makes it even more imperative that we understand fundamentals. Many of our control problems stem from the use of new devices as a solution to problems that are, in fact, control design errors. New gadgets, for example, Direct Digital Controls (DDC), will not solve basic problems and may even compound them. None-the-Iess, you will find an extensive discussion of DDC because I think it is the probable future in HVAC control. But it must be applied with a good understanding of fundamentals. The second reason is that I keep learning and need to pass on my new and improved understanding to my readers. Thus you will find a number of small but important revisions, a dissertation on control modes, and a much more detailed discussion of how electronic control devices work. There are a few places where I have corrected what I now perceive to be errors. I apologize for these. I have been much encouraged by the acceptance of this book in the past, and I hope that this new edition will be helpful. Thank you for your support. |
| cascade tower fan manual: Circular Z. National Fertilizer Development Center (U.S.), 1970 |
| cascade tower fan manual: Oil and Gas Production Handbook: An Introduction to Oil and Gas Production Havard Devold, 2013 |
| cascade tower fan manual: Manual of Engineering Drawing Colin H. Simmons, Dennis E. Maguire, 2003-10-21 The Manual of Engineering Drawing has long been recognised as the student and practising engineer's guide to producing engineering drawings that comply with ISO and British Standards. The information in this book is equally applicable to any CAD application or manual drawing. The second edition is fully in line with the requirements of the new British Standard BS8888: 2002, and will help engineers, lecturers and students with the transition to the new standards.BS8888 is fully based on the relevant ISO standards, so this book is also ideal for an international readership. The comprehensive scope of this book encompasses topics including orthographic, isometric and oblique projections, electric and hydraulic diagrams, welding and adhesive symbols, and guidance on tolerancing.Written by a member of the ISO committee and a former college lecturer, the Manual of Engineering Drawing combines up-to-the-minute technical accuracy with clear, readable explanations and numerous diagrams. This approach makes this an ideal student text for vocational courses in engineering drawing and undergraduates studying engineering design / product design.Colin Simmons is a member of the BSI and ISO Draughting Committees and an Engineering Standards Consultant. He was formerly Standards Engineer at Lucas CAV.* Fully in line with the latest ISO Standards* A textbook and reference guide for students and engineers involved in design engineering and product design* Written by a former lecturer and a current member of the relevant standards committees |
| cascade tower fan manual: Op Amps for Everyone Ron Mancini, 2003 The operational amplifier (op amp) is the most versatile and widely used type of analog IC, used in audio and voltage amplifiers, signal conditioners, signal converters, oscillators, and analog computing systems. Almost every electronic device uses at least one op amp. This book is Texas Instruments' complete professional-level tutorial and reference to operational amplifier theory and applications. Among the topics covered are basic op amp physics (including reviews of current and voltage division, Thevenin's theorem, and transistor models), idealized op amp operation and configuration, feedback theory and methods, single and dual supply operation, understanding op amp parameters, minimizing noise in op amp circuits, and practical applications such as instrumentation amplifiers, signal conditioning, oscillators, active filters, load and level conversions, and analog computing. There is also extensive coverage of circuit construction techniques, including circuit board design, grounding, input and output isolation, using decoupling capacitors, and frequency characteristics of passive components. The material in this book is applicable to all op amp ICs from all manufacturers, not just TI. Unlike textbook treatments of op amp theory that tend to focus on idealized op amp models and configuration, this title uses idealized models only when necessary to explain op amp theory. The bulk of this book is on real-world op amps and their applications; considerations such as thermal effects, circuit noise, circuit buffering, selection of appropriate op amps for a given application, and unexpected effects in passive components are all discussed in detail. *Published in conjunction with Texas Instruments *A single volume, professional-level guide to op amp theory and applications *Covers circuit board layout techniques for manufacturing op amp circuits. |
| cascade tower fan manual: Chemical Engineering Design Gavin Towler, Ray Sinnott, 2012-01-25 Chemical Engineering Design, Second Edition, deals with the application of chemical engineering principles to the design of chemical processes and equipment. Revised throughout, this edition has been specifically developed for the U.S. market. It provides the latest US codes and standards, including API, ASME and ISA design codes and ANSI standards. It contains new discussions of conceptual plant design, flowsheet development, and revamp design; extended coverage of capital cost estimation, process costing, and economics; and new chapters on equipment selection, reactor design, and solids handling processes. A rigorous pedagogy assists learning, with detailed worked examples, end of chapter exercises, plus supporting data, and Excel spreadsheet calculations, plus over 150 Patent References for downloading from the companion website. Extensive instructor resources, including 1170 lecture slides and a fully worked solutions manual are available to adopting instructors. This text is designed for chemical and biochemical engineering students (senior undergraduate year, plus appropriate for capstone design courses where taken, plus graduates) and lecturers/tutors, and professionals in industry (chemical process, biochemical, pharmaceutical, petrochemical sectors). New to this edition: - Revised organization into Part I: Process Design, and Part II: Plant Design. The broad themes of Part I are flowsheet development, economic analysis, safety and environmental impact and optimization. Part II contains chapters on equipment design and selection that can be used as supplements to a lecture course or as essential references for students or practicing engineers working on design projects. - New discussion of conceptual plant design, flowsheet development and revamp design - Significantly increased coverage of capital cost estimation, process costing and economics - New chapters on equipment selection, reactor design and solids handling processes - New sections on fermentation, adsorption, membrane separations, ion exchange and chromatography - Increased coverage of batch processing, food, pharmaceutical and biological processes - All equipment chapters in Part II revised and updated with current information - Updated throughout for latest US codes and standards, including API, ASME and ISA design codes and ANSI standards - Additional worked examples and homework problems - The most complete and up to date coverage of equipment selection - 108 realistic commercial design projects from diverse industries - A rigorous pedagogy assists learning, with detailed worked examples, end of chapter exercises, plus supporting data and Excel spreadsheet calculations plus over 150 Patent References, for downloading from the companion website - Extensive instructor resources: 1170 lecture slides plus fully worked solutions manual available to adopting instructors |
| cascade tower fan manual: The Craft and Science of Coffee Britta Folmer, 2016-12-16 The Craft and Science of Coffee follows the coffee plant from its origins in East Africa to its current role as a global product that influences millions of lives though sustainable development, economics, and consumer desire.For most, coffee is a beloved beverage. However, for some it is also an object of scientifically study, and for others it is approached as a craft, both building on skills and experience. By combining the research and insights of the scientific community and expertise of the crafts people, this unique book brings readers into a sustained and inclusive conversation, one where academic and industrial thought leaders, coffee farmers, and baristas are quoted, each informing and enriching each other.This unusual approach guides the reader on a journey from coffee farmer to roaster, market analyst to barista, in a style that is both rigorous and experience based, universally relevant and personally engaging. From on-farming processes to consumer benefits, the reader is given a deeper appreciation and understanding of coffee's complexity and is invited to form their own educated opinions on the ever changing situation, including potential routes to further shape the coffee future in a responsible manner. - Presents a novel synthesis of coffee research and real-world experience that aids understanding, appreciation, and potential action - Includes contributions from a multitude of experts who address complex subjects with a conversational approach - Provides expert discourse on the coffee calue chain, from agricultural and production practices, sustainability, post-harvest processing, and quality aspects to the economic analysis of the consumer value proposition - Engages with the key challenges of future coffee production and potential solutions |
| cascade tower fan manual: Instrument Engineers' Handbook, Volume Two Bela G. Liptak, 2018-10-08 The latest update to Bela Liptak's acclaimed bible of instrument engineering is now available. Retaining the format that made the previous editions bestsellers in their own right, the fourth edition of Process Control and Optimization continues the tradition of providing quick and easy access to highly practical information. The authors are practicing engineers, not theoretical people from academia, and their from-the-trenches advice has been repeatedly tested in real-life applications. Expanded coverage includes descriptions of overseas manufacturer's products and concepts, model-based optimization in control theory, new major inventions and innovations in control valves, and a full chapter devoted to safety. With more than 2000 graphs, figures, and tables, this all-inclusive encyclopedic volume replaces an entire library with one authoritative reference. The fourth edition brings the content of the previous editions completely up to date, incorporates the developments of the last decade, and broadens the horizons of the work from an American to a global perspective. Béla G. Lipták speaks on Post-Oil Energy Technology on the AT&T Tech Channel. |
| cascade tower fan manual: Hydrocarbon Processing , 1982 |
| cascade tower fan manual: Rules of Thumb for Chemical Engineers Carl Branan, 2002 Fractionators, separators and accumulators, cooling towers, gas treating, blending, troubleshooting field cases, gas solubility, and density of irregular solids * Hundreds of common sense techniques, shortcuts, and calculations. |
| cascade tower fan manual: Scientific and Technical Aerospace Reports , 1995 Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database. |
| cascade tower fan manual: Extrusion Harold F. Giles Jr, John R. Wagner Jr., Eldridge M. Mount III, 2013-09-21 The second edition of Extrusion is designed to aid operators, engineers, and managers in extrusion processing in quickly answering practical day-to-day questions. The first part of the book provides the fundamental principles, for operators and engineers, of polymeric materials extrusion processing in single and twin screw extruders. The next section covers advanced topics including troubleshooting, auxiliary equipment, and coextrusion for operators, engineers, and managers. The final part provides applications case studies in key areas for engineers such as compounding, blown film, extrusion blow molding, coating, foam, and reprocessing. This practical guide to extrusion brings together both equipment and materials processing aspects. It covers basic and advanced topics, for reference and training, in thermoplastics processing in the extruder. Detailed reference data are provided on such important operating conditions as temperatures, start-up procedures, shear rates, pressure drops, and safety. - A practical guide to the selection, design and optimization of extrusion processes and equipment - Designed to improve production efficiency and product quality - Focuses on practical fault analysis and troubleshooting techniques |
| cascade tower fan manual: LRFD Guide Specifications for the Design of Pedestrian Bridges American Association of State Highway and Transportation Officials, 2009 |
| cascade tower fan manual: Introduction to Aircraft Flight Mechanics Thomas R. Yechout, 2003 Based on a 15-year successful approach to teaching aircraft flight mechanics at the US Air Force Academy, this text explains the concepts and derivations of equations for aircraft flight mechanics. It covers aircraft performance, static stability, aircraft dynamics stability and feedback control. |
| cascade tower fan manual: Indexes United States. Environmental Protection Agency, 1983 |
| cascade tower fan manual: Manual of Digital Earth Huadong Guo, Michael F. Goodchild, Alessandro Annoni, 2019-11-18 This open access book offers a summary of the development of Digital Earth over the past twenty years. By reviewing the initial vision of Digital Earth, the evolution of that vision, the relevant key technologies, and the role of Digital Earth in helping people respond to global challenges, this publication reveals how and why Digital Earth is becoming vital for acquiring, processing, analysing and mining the rapidly growing volume of global data sets about the Earth. The main aspects of Digital Earth covered here include: Digital Earth platforms, remote sensing and navigation satellites, processing and visualizing geospatial information, geospatial information infrastructures, big data and cloud computing, transformation and zooming, artificial intelligence, Internet of Things, and social media. Moreover, the book covers in detail the multi-layered/multi-faceted roles of Digital Earth in response to sustainable development goals, climate changes, and mitigating disasters, the applications of Digital Earth (such as digital city and digital heritage), the citizen science in support of Digital Earth, the economic value of Digital Earth, and so on. This book also reviews the regional and national development of Digital Earth around the world, and discusses the role and effect of education and ethics. Lastly, it concludes with a summary of the challenges and forecasts the future trends of Digital Earth. By sharing case studies and a broad range of general and scientific insights into the science and technology of Digital Earth, this book offers an essential introduction for an ever-growing international audience. |
| cascade tower fan manual: Fans and Pumps Canada. Energy, Mines and Resources Canada, 1987 Manual on fans and pumps, providing information on basic operatingprinciples, with simplified equations for estimating the energy requirements, both retrofit and housekeeping; equipment/systems, describingthe devices and discussing their characteristics with regard to energyconsumption; and a series of energy management opportunities, includingworksheets to produce sample calculations of energy savings, cost savings andsimple payback. A glossary is included. |
| cascade tower fan manual: Measurement and Computation of Streamflow Saul Edward Rantz, 1982 |
| cascade tower fan manual: Superpave Mix Design Asphalt Institute, 2001-01-01 |
| cascade tower fan manual: Chemical Process Equipment - Selection and Design (Revised 2nd Edition) James R. Couper, W Roy Penney, James R. Fair PhD, 2009-08-11 A facility is only as efficient and profitable as the equipment that is in it: this highly influential book is a powerful resource for chemical, process, or plant engineers who need to select, design or configures plant sucessfully and profitably. It includes updated information on design methods for all standard equipment, with an emphasis on real-world process design and performance. - The comprehensive and influential guide to the selection and design of a wide range of chemical process equipment, used by engineers globally; Copious examples of successful applications, with supporting schematics and data to illustrate the functioning and performance of equipment - Revised edition, new material includes updated equipment cost data, liquid-solid and solid systems, and the latest information on membrane separation technology - Provides equipment rating forms and manufacturers' data, worked examples, valuable shortcut methods, rules of thumb, and equipment rating forms to demonstrate and support the design process - Heavily illustrated with many line drawings and schematics to aid understanding, graphs and tables to illustrate performance data |
| cascade tower fan manual: Power Plant Instrumentation and Control Handbook Swapan Basu, Ajay Kumar Debnath, 2019-06-09 Power Plant Instrumentation and Control Handbook, Second Edition, provides a contemporary resource on the practical monitoring of power plant operation, with a focus on efficiency, reliability, accuracy, cost and safety. It includes comprehensive listings of operating values and ranges of parameters for temperature, pressure, flow and levels of both conventional thermal power plant and combined/cogen plants, supercritical plants and once-through boilers. It is updated to include tables, charts and figures from advanced plants in operation or pilot stage. Practicing engineers, freshers, advanced students and researchers will benefit from discussions on advanced instrumentation with specific reference to thermal power generation and operations. New topics in this updated edition include plant safety lifecycles and safety integrity levels, advanced ultra-supercritical plants with advanced firing systems and associated auxiliaries, integrated gasification combined cycle (IGCC) and integrated gasification fuel cells (IGFC), advanced control systems, and safety lifecycle and safety integrated systems. - Covers systems in use in a wide range of power plants: conventional thermal power plants, combined/cogen plants, supercritical plants, and once through boilers - Presents practical design aspects and current trends in instrumentation - Discusses why and how to change control strategies when systems are updated/changed - Provides instrumentation selection techniques based on operating parameters. Spec sheets are included for each type of instrument - Consistent with current professional practice in North America, Europe, and India - All-new coverage of Plant safety lifecycles and Safety Integrity Levels - Discusses control and instrumentation systems deployed for the next generation of A-USC and IGCC plants |
| cascade tower fan manual: Journal of the Society of Chemical Industry Society of Chemical Industry (Great Britain), 1915 |
| cascade tower fan manual: Process Design Manual, Wastewater Treatment Facilities for Sewered Small Communities Camp, Dresser & McKee, 1977 |
| cascade tower fan manual: Waterfront Facilities Inspection and Assessment Waterfront Inspection Task Committee, 2015 MOP 130 provides engineers with guidelines and tools for inspecting and evaluating the condition of waterfront structures located in seawater and freshwater environments. |
| cascade tower fan manual: Energy Research Abstracts , 1981 |
| cascade tower fan manual: An Inquiry Into Modes of Existence Bruno Latour, 2013-08-19 In a new approach to philosophical anthropology, Bruno Latour offers answers to questions raised in We Have Never Been Modern: If not modern, what have we been, and what values should we inherit? An Inquiry into Modes of Existence offers a new basis for diplomatic encounters with other societies at a time of ecological crisis. |
TROUBLESHOOTING - Costco Wholesale
40-INCH TOWER FAN INSTRUCTION MANUAL Problem Possible Cause Solution The fan is not operating. The plug is not fully inserted into the wall outlet. Make sure that the plug is fully …
User Manual - images-na.ssl-images-amazon.com
SECURING THE TOWER FAN TO THE PEDESTAL • Carefully turn the fan on its side and place on a table. Place the power cord through the center of the pedestal and base assembly. • Align …
Cascade Tower Fan Manual (book) - old.icapgen.org
Table of Contents Cascade Tower Fan Manual 1. Understanding the eBook Cascade Tower Fan Manual The Rise of Digital Reading Cascade Tower Fan Manual Advantages of eBooks Over …
Cascade 40 Tower Fan Assembly Guide - Blackstone …
Align, and then insert, the plastic pegs of the BASE TOP with the holes on the BASE BOTTOM until both pieces snap together. Now that the base is connected together, turn the tower fan …
Cascade Use, Care, and Installation Guide - Costco Wholesale
Grease should not be allowed to accumulate on fan or fi lter. Use proper pan size. Always use cookware appropriate for the size of the surface element. Keep fan, fi lters and grease laden …
PLEASE READ AND SAVE THESE INSTRUCTIONS
1. Use the fan only as described in this manual. Other use is not recommended and may cause fire, electric shock or injury to persons. 2. This product is intended for household use ONLY …
Parts Manual
Do you have questions you need answered right now? Call your nearest Cascade Parts Department. Visit us online at www.cascorp.com.
40 Tower Fan - images-na.ssl-images-amazon.com
Place the Tower Fan on the package foam or other soft surfaces and invert it to avoid scratch mark when install the base. Take away the two parts of the base from packaging box.
Cascade Tower Fan Manual (Download Only) - netstumbler.com
Cascade tower fans, unlike traditional bladed fans, utilize a narrow tower design with a series of internal slats or vents. Air is drawn in at the base and expelled upwards in a gentle, oscillating …
Installation and Instruction Manual Cascade System
Multiple tankless water heaters can be connected via a cascade communication cable to create a bank of water heaters that work in tandem. Up to 16 water heaters can be controlled by a …
OSCILLATING FAN INSTRUCTION MANUAL - Blackstone …
WARRANTY: This fan includes a one (1) year warranty, which covers manufacturer defects and workmanship under normal use. Warranty is offered only to the original purchaser. Proof of …
To clean your fan, first turn it OFF and UNPLUG the unit.
Read all instructions before using this product. Use this fan only as described in this manual. Any other use not recommend-ed by the manufacturer may cause fire, electrical shock or injury to …
WHEN USING ELECTRICAL APPLIANCES, BASIC PRECAUTIONS …
DO NOT operate the fan in the presence of explosive and/or flammable fumes. DO NOT place the fan or any parts near an open flame, cooking or other heating appliances. Extreme …
Cascade Tower Fan Manual Copy - old.icapgen.org
resources including 1170 lecture slides and a fully worked solutions manual are available to adopting instructors This text is designed for chemical and biochemical engineering students …
Parts Manual
Ordering Information – Parts, Service and Operator Guide literature is sold through the Cascade Parts Depot. All dealerships with an open account, please indicate quantity desired and …
FAN & CERAMIC HEATER COMBO - Blackstone International Ltd.
Tower Fan Speed Control a. After turning the tower fan ON using button 1, press the tower fan speed button to increase the speed from F1-F4 (F1, F2, F3, F4). If the speed button is pressed …
13-INCH PERSONAL FAN INSTRUCTION MANUAL
Read all instructions before using this product. Use this fan only as described in this manual. Any other use not recommended by the manufacturer may cause fire, electrical shock or injury to …
Cascade Tower Fan Manual (book) - old.icapgen.org
Cascade Tower Fan Manual is a crucial topic that needs to be grasped by everyone, ranging from students and scholars to the general public. This book will furnish comprehensive and in-depth
UG应用技巧之一（自定义右键弹出菜单和快捷键） - NX(UGS)技术 …
Apr 21, 2006 · 一、自定义右键弹出菜单和快捷键： UG的右键弹出菜单包含了一些我们常用的功能，比如Roate、Fit等，为了使用的更加方便，我们也可以自己打造！
cad中英对照命令大全 - CAD设计网 (askcad.com) - 信息资讯
cad中英对照命令大全 - CAD设计网(askcad.com) - 信息资讯 - AutoCAD二维论坛是国内最专业、发展最快的AutoCAD设计讨论基地，论坛云集高手，提供CAD的教程，练习，考试，软件下 …
AutoCAD机械制图英语词汇 (很全） - AutoCAD二维设计（含画法 …
Jan 8, 2007 · AutoCAD机械制图英语词汇英文词汇 大陆词汇 台湾词汇 2D Solid 二维实体 2D 实面 2D Wireframe 二维线框 3D Array 三维阵列 3D 阵列 3D Dynamic View 三维动态 ...
AutoCAD机械制图英语词汇（很全） - CAD设计网(askcad.com)
AutoCAD机械制图英语词汇（很全） - CAD设计网(askcad.com) - 信息资讯 - AutoCAD二维论坛是国内最专业、发展最快的AutoCAD设计讨论基地，论坛云集高手，提供CAD的教程，练习， …
cad中英对照命令大全 - AutoCAD二维设计（含画法几何） - CAD …
2D Solid 二维实体 2D 实面 2D Wireframe 二维线框 3D Array 三维阵列 3D 阵列 3D Dynamic View 三维动态观察 3D 动态检视 3d objects 三维物体 3D 物件 3D Orbi ... cad中英对照命令大全 …
机械设计名词术语中英文对照表 - 国产CAD软件专区 - CAD设计论坛
Jul 9, 2012 · 机械设计名词术语中英文对照表阿基米德蜗杆 Archimedes worm安全系数 safety factor; factor of safety安全载荷 safe load凹面、凹度 concavity扳手 wrench ...
