Transcription
Portable Clean Room & HoodFINAL REPORTKatie HoffmanDaniel MarquezHannah Reed2018-2019Department of Mechanical EngineeringNorthern Arizona UniversityFlagstaff, AZ 86001Project Sponsor: Aneuvas Technology, Inc.Faculty Advisor: Dr. Timothy BeckerInstructor: Dr. Sarah Oman
DISCLAIMERThis report was prepared by students as part of a university course requirement. While considerable efforthas been put into the project, it is not the work of licensed engineers and has not undergone the extensiveverification that is common in the profession. The information, data, conclusions, and content of thisreport should not be relied on or utilized without thorough, independent testing and verification.University faculty members may have been associated with this project as advisors, sponsors, or courseinstructors, but as such they are not responsible for the accuracy of results or conclusions.ii
EXECUTIVE SUMMARYThe objective of the clean hood project, proposed by Aneuvas Technology, Inc, is to design and build aportable clean hood, to fully design a portable clean room, and manufacture the clean room frame. Theproject is overseen by the client/faculty advisor Dr. Timothy Becker who leads the BioengineeringDevices Lab, affiliated with Mechanical Engineering and the Center for Bioengineering Innovation (CBI).The client needs a 72”x96”x84” clean room to perform training and testing with microcatheters and isalso in need of a 24”x48”x40” clean hood to run small equipment under, specifically the client’srheometer. The primary requirements given by the client are that both units maintain a positive pressure,be portable, easily transportable, and produces a foreign particle clean environment.The portable hood will be constructed of three separate pieces consisting of a hollow aluminum frame, apolycarbonate viewing case, and a Fan Filter Unit (FFU). The aluminum frame will support the totalweight of the FFU, this will be to prevent the polycarbonate from fracturing or cracking. The aluminumframe will fit over the polycarbonate viewing window and seal the FFU to the viewing window. Therewill be a rubber seal that will prevent pressure loss between the three components. The polycarbonateviewing window will have a hinged door that creates access to the client’s product being tested, and toadjust the rheometer that will primarily be operated within the hood.The portable room will be compiled of four main parts, this includes a powder coated steel framing, theplastic lining and the two FFUs. The powder coated steel framing for the room will disassemble, byseparating into smaller components, this is to simplify set up, allow portability and to lower the totalamount of parts. Attached to the framing will be a detachable plastic lining, this creates visibility into theroom and maintains the positive pressure. The plastic lining will be attached to the aluminum framingwith 3M Dual Lock, that acts like Velcro, but is much stronger and can hold more weight. It wasdetermined that two fans would be required to maintain a clean environment in the room. The room willprimarily be used to preform tests utilizing a microcatheter in a semi-sterile environment. The clean roomand hood will both create a clean environment on the FFUs lowest setting, allowing for additionalcleanliness by turning up the speed of air flow.Analytical calculations show the clean room and hood will maintain positive pressure with two fan unitsfor the room and one for the hood. The structural analysis performed shows that the framing for the roomwill not fail under the load of both the FFUs resting on top. The fan filter analysis showed the maximumcleanliness classification the room and hood can sustain, along with indication for when the filters need tobe changed. Calculations having been completed, the team moves to building and testing the clean roomand hood.iii
ACKNOWLEDGEMENTSThe capstone team would like to extend our gratitude to all who have assisted the team throughout allaspects of the project. Aneuvas Technology Inc., Dr. Timothy Becker, who gave the team a challengingproposal which then allowed the team to research and design two units that will benefit the client’sresearch and manufacturing. The capstone teacher Dr. Sarah Oman, who supported, advised, and gaveconstructive criticism through the year. NAU’s Machine Shop for providing open space, access to varioustools, and manufacturing mentors.iv
TABLE OF CONTENTSContentsDISCLAIMER . iiEXECUTIVE SUMMARY . iiiACKNOWLEDGEMENTS . ivTABLE OF CONTENTS . v1BACKGROUND . 11.1 Introduction . 11.2 Project Description . 11.3 Original System . 12REQUIREMENTS . 22.1 Customer Requirements (CRs) . 22.2 Engineering Requirements (ERs) . 22.3 Testing Procedures (TPs) . 32.3.1 Area . 32.3.2 Pressure . 32.3.3 Cost . 42.3.4 Weight . 42.3.5 Assembly Time . 42.3.6 Power FFU . 42.3.7 Particle Count. 42.3.8 Velocity . 42.4 House of Quality (HoQ) . 43EXISTING DESIGNS . 53.1 Design Research . 53.2 System Level . 53.2.1 Existing Design #1: Vertical Laminar Flow Hood . 53.2.2 Existing Design #2: Horizontal Laminar Flow Hood . 63.2.3 Existing Design #3: NCI 8’x8’x8’ Portable Clean Room . 63.2.4 Existing Design #4: Clean Air Products 6’x8’x8’ Portable Clean Room. 73.3 Functional Decomposition. 83.3.1 Black Box Model . 83.3.2 Work Process Diagram. 83.3.3 Functional Model . 93.4 Subsystem Level . 103.4.1 Subsystem #1: Fan Filter Unit (FFU). 103.4.2 Subsystem #2: Portable Clean Room . 103.4.3 Subsystem #3: Portable Clean Hood . 114DESIGNS CONSIDERED . 124.1 Portable Hood Designs . 124.1.1 Design #1: Portable Hood with Exterior Frame . 124.1.2 Design #2: Slide on External Frame Clean Hood . 124.1.3 Design #3: Vertical Laminar Flow Hood with Solid Frame . 134.1.4 Design #4: Horizontal Laminar Flow Hood with no Frame . 144.2 Portable Clean Room Designs . 154.2.1 Design #5: Clean Room with Detachable Frame . 154.2.2 Design #6: Double Flap Clean room. 15v
4.2.3 Design #7: Portable Clean Room Single Flaps . 16DESIGN SELECTED – First Semester . 175.1 Rationale for Design Selection . 175.2 Design Description . 185.2.1 Engineering Calculations . 185.2.2 Model Drawings . 196PROPOSED DESIGN – First Semester . 216.1 Implementation of Design . 216.2 Bill of Materials . 216.3 Final Design Assembly View and Exploded View . 217IMPLEMENTATION . 237.1 Manufacturing . 237.2 Design Changes . 278Testing . 298.1 Room Testing . 298.2 Hood Testing. 308.2.1 Area ( 0.743 m²) . 308.2.2 Pressure ( 78000 Pa) . 318.2.3 Cost ( 2000) . 338.2.4 Weight ( 45.36kg) . 338.2.5 Assembly Time ( 10 min) . 338.2.6 Power FFU (520 W) . 348.2.7 Particle Count ( ISO10) . 348.2.8 Velocity (m/s) . 359CONCLUSION . 369.1 Contribution to Project Success . 369.2 Opportunities for Improvement . 3710REFERENCES . 38APPENDICES . 39Appendix A: House of Quality . 39Appendix B: Portable Hood with Adjustable Frame . 40Appendix C: Portable Hood with Tabbed Framing. 40Appendix D: Technical Analysis. 40Appendix E: Computational Fluid Dynamics Analysis Visual . 55Appendix F: Bill of Materials . 55Appendix G: Gantt Chart . 555vi
1 BACKGROUND1.1 IntroductionThe clean hood project was created by Aneuvas Technology, Inc and is overseen by Dr. Timothy Becker.The project objective was to design and build a portable clean hood, fully design a portable clean roomand manufacture the frame for the room. The clean room and hood are to produce and maintain a positivepressure, which will reduce the number of foreign particles in the structures. This makes a cleanenvironment for which the sponsor can conduct sterile experiments and test in. The companymanufactures and analyzes minimal invasive microcatheter medical devices, used to treat aneurisms andother vascular defects in the brain. This project will benefit the client’s research and development of theirproducts by producing a clean low particle count environment.1.2 Project DescriptionFollowing the original project description provided by Aneuvas Technology, Inc.,“The scope of this project is to design, build, and test a fan-filter unit (FFU), a curtain clean roomarea, and a laminar flow hood to help establish sterile manufacture capabilities. The flow hood(2’x 4’) and clean room (4’x 6’) must have the ability to be disassembled and reassembled, cleanand sterilized, and portable.”The flow hood is to be 24”x 48”x 40” so it can fit over small equipment within the client’s lab, along withan FFU placed on top of the frame to induce a positive pressure of clean air. The clean room has beenchanged to be 72”x 96”x 84” and will be fully designed and include the manufacturing of the steel frameper clients request. It must have the ability to be assembled, disassembled, and carried by 3-4 people; itwill have two FFUs placed on top of the frame which will produce a positive pressure of clean air within.1.3 Original SystemThis project involved the design of a completely new portable clean room and clean hood. There was nooriginal system when this project began.1
2 REQUIREMENTSThe requirements of this project include the customer requirements and the engineering requirements. Thecustomer requirements were provided directly from the client/sponsor. The engineering requirements arederived from the customer requirements using the House of Quality (HoQ) and were given a unit ofmeasurement and a targeted value. Then the engineering requirements are put through a testing procedure(TPs) to verify if the customer requirements were met.2.1 Customer Requirements (CRs)The customer requirements were obtained during the first client meeting and from the project descriptionthey are listed below. Noise was removed from the CRs per clients request because it was not needed tobe measured.Table 1: Customer Requirements2.2 Engineering Requirements (ERs)From the customer requirements, engineering requirements were compiled to meet the CRs and are listedbelow. The different parameters used for the technical terms are given by Table 2. Measuring the area ofboth the hood and the room is in terms on 𝑚2 . The second parameter would be the pressure for each roomand is measured in pascals. Also identifying the total potential cost for the room and the hood which isdenoted in dollars. An important factor for the ability to transport both the hood and the room is theassembly time which is in minutes. The power generated for both systems is denoted by watts. The𝑚velocity for each fan unit will be measured in 𝑠 which will be used to understand positive pressurethrough the system. Sound and material were removed per clients request due to both being of minimalimportance to the client.2
Table 2. Engineering Requirements2.3 Testing Procedures (TPs)This section discusses the testing procedures considered to verify each customer requirement had beenmet.2.3.1 AreaTo test the area of both units we measured each side 2-3 times with a tape measure for accuracy and thencalculate the area with the dimensions measured. The tape measure was previously owned by a teammember.2.3.2 PressureThe pressure was measured with a pressure DAC and 2 pressure transducers which connected to acomputer with the program LabVIEW set up. The pressure inside the hood unit and the atmosphericpressure outside were measured. The measurement from the transducers was carried to a DAC whichtransferred the data to the computer. The computer program LabVIEW interpreted and recorded the datacollect by the transducers and DAC. Then LabVIEW converted the data to a readable pressuremeasurement. Two readings were conducted at seven different locations within the hood. Onemeasurement 6” below the FFU, a measurement at the bottom of the unit, on all four walls, and outsidethe unit. Measuring each location 3 times ensured accuracy. The testing equipment was purchased by theclient.3
2.3.3 CostTo verify the cost was met, the budget and bill of materials were updated and evaluated together for everynew change. This verified the budget was met, below expectation, or exceeded.2.3.4 WeightThe weight of both units was estimated with Solidworks because they were too large to fit onto a scale.Northern Arizona University had access to Solidworks for students.2.3.5 Assembly TimeA timer was used to measure assembly time, each unit was measured separately and then the disassemblyof each unit. Measuring was done once because of the shape of the units and the process ofassembly/disassembly does not change.2.3.6 Power FFUTo test if the FFU had power was done by plugging in the unit and turning it on. Per the manual of TerraUniversal FFU the power of the fan filter unit at its lowest setting is 393 Watts [2].2.3.7 Particle CountDue to budget constraints a particle counter could not be obtained to count the particles within each unit.To obtain an estimate of particles within each unit, the information was obtained from the manufacturer,the HEPA filter, and the size of the room vs the number of FFUs.2.3.8 VelocityFrom the pressures measured and tested with the pressure transducers the velocity was calculated byusing the pipe flow energy equation. The velocity of the FFUs are given by Terra Universal and each unitoutputs about 0.4724 meters per second as seen in Appendix D.2.4 House of Quality (HoQ)The House of Quality, as seen in Appendix A, relates and compares the customer requirements toengineering requirements, to meet the client’s expectations and desires for the project. The HoQ gives avisual of ERs that have greater importance or higher scores in relation to the ranked CRs. Each ER isgiven a specific target value that will allow for the design to meet the client’s needs. In Table 1, the resultsof the weighted CRs are from the quality function deployment (QFD) chart, as seen in Appendix A, thepositive pressure and inexpensiveness were weighted the heaviest because they were emphasized the mostby the client. While visibility was weighted the lowest because the given material is already transparent.In Table 2 the scoring of the ERs was from Appendix A, the pressure and number of particles had thehighest score of 13. While the lowest scored ER was sound with a score of 1.4. Each customerrequirement was obtained by the project description as well as the client. The results from the HoQallowed the team to prioritize the CRs and ERs needed to successfully complete the design and fulfill theclient’s desires.4
3 EXISTING DESIGNSThis section covers the design research, system level, functional decomposition and the subsystem level.Research was conducted to obtain a better understanding of portable clean rooms and hoods, theirclassification, the FFUs, and the type of material used for them. There are a variety of different designsfor both units, most clean rooms and hoods have similar features but key differences. Most clean roomshave clear walls for manufacturing visibility purposes, as well as two FFUs that provide positive pressurein the room. Clean hoods can be either a vertical laminar flow or a horizontal laminar flow with clearwalls to direct the flow out through the opening. Another difference is the functionality of the room, mostportable clean rooms have casters allowing movement. These existing designs aided in the process ofdesign concept generations for the hood and room, suiting the client’s needs.3.1 Design ResearchThere are many designs and concepts of portable clean rooms and hoods. Various companies were foundthrough online research, that manufacture portable clean rooms and hoods. There are two types of cleanhoods: vertical laminar flow and horizontal laminar flow. Clean Air Products and Terra Universal are thetop two manufacturers out of many that were researched and analyzed. The vertical and horizontal hooddesigns were reviewed to verify that both meet the CR criteria. The vertical flow hood has an FFU placedon top which then produces a vertical flow of air downward. The horizontal flow hood has an FFU placedat the back of the hood blowing a horizontal flow of air towards the front. For portable clean rooms thereare two styles, a soft-walled and a hard-walled clean room. The hard wall clean room can be both apermanent and portable room with hard walls all around. The soft wall clean room is primarily a portablebased room with soft clear walls all around. All existing designs can be seen in the sections below. Thesedesigns were evaluated to justify which concept best suited the client’s conception.3.2 System LevelThere are a few existing designs that represent potential design concepts for this project. The clean roomsavailable with similar design requirements pertaining to this project are sold by various companies aroundthe US. The requirements for most clean rooms are similar, they involve creating a laminar air flow andproducing positive air pressure to prevent particles from accumulating. Clean rooms vary in ISOclassification which pertain to the number of particles per cubic area. Each clean room has differentstandards given the fan utilized, and these standards vary from 10,000 particles per cubic area to 100,000particles per cubic area. Existing designs like a vertical laminar flow would be useful to create a cleanroom over a work area. Where a horizontal laminar flow hood is practical for some applications, pushingthe flow towards the user, but for this project it would not suit the client’s needs.3.2.1 Existing Design #1: Vertical Laminar Flow HoodAs seen in Figure 1 below, this hood produces a vertical laminar flow of clean air over the work space.This design is an ideal concept to analyze because it meets most of the CRs needed to satisfy thecustomer. It produces positive pressure, clean air, durable, reliable, and portable. It does not meet the costor visibility requirement that the client requests.5
Figure 1. Vertical Laminar Flow Hood [4]3.2.2 Existing Design #2: Horizontal Laminar Flow HoodThe horizontal laminar flow hood, as seen in Figure 2, produces a horizontal laminar flow towards theuser. This design meets some of the requirements but is not the best design to analyze because the FFU islocated on the back side of the hood. This design does not follow the client’s specifications, which washaving the FFU on the top of the hood due to limited surrounding space. Overall, a great perspective butdoes not meet the CRs entirely.Figure 2. Horizontal Laminar Flow Hood [4]3.2.3 Existing Design #3: NCI 8’x8’x8’ Portable Clean RoomThe NCI portable clean room is 8’x8’x8’, seen in Figure 3, fulfills most of the customer requirementsneeded for the clean room project. This portable clean room exceeds the size needed for the project but is6
portable. The main concern for this portable clean room was if it could be carried by three to four people,as specified in the CR’s. Due to the size of this clean room created by NCI, it may not meet therequirement of portability for the clean room project. Nevertheless, the design can be used for creativeidea generation for the final design concept of the clean room.Figure 3. 8'x8'x8' Portable Clean Room [3]3.2.4 Existing Design #4: Clean Air Products 6’x8’x8’ Portable Clean RoomIn Figure 4, Clean Air Products created a 6’x8’x8’ portable clean room, fulfilling some of therequirements our client requested be met. The dimensions exceed the required size needed, but it doesmeet the engineering requirement of being portable. The size of the room is important since it will beused in different sized areas. The concept of this clean room could be used as reference, since it meetssome of the customer requirements needed for the clean room project.Figure 4. 6’x8’x8’ Portable clean room [1]7
3.3 Functional DecompositionThe functional decomposition breaks down the entire system into smaller components. For this system ablack box model and a functional model were created to obtain a better understanding and to simplify theproject into smaller sections. These sections incorporate the basic principles of the black box and expandon it. Tracking the different flows like material, energy, and signal to create a logical flow of the processesgoing on within the system. The functional model takes the black box model and applies it to each unitand elaborates in detail.3.3.1 Black Box ModelThe black box model, Figure 5, portrays a simple overview of the inputs and outputs of positive pressurein a structure. The three flows through the hood and the room are a material flow, energy flow, and signalflow. For material flow, cleaning the room and utilization of the user’s hands are expanded upon andcreate a flow of materials in and out of the system. Energy flow was a section of interest since it createsthe main functionality of the clean room. The fans capture the kinetic energy coming from the clean roomthen releases it as laminar air flow which creates the positive air pressure. The electrical energy is used topower the fans which then engages the fans functionality. Human energy is introduced during systemoperation and when humans are operating within the system. Signal flow is used to indicate whether thesystem is under operation and this allows the user to understand whether the clean room is on or off.Figure 5. Black Box Model3.3.2 Work Process DiagramThe work process diagram shows the hierarchical type work needed to create the clean room as proposedby the customer. It starts with the project description, then ideas are generated for the project. Researchwas conducted using journals, the internet, and companies to obtain a better understanding of cleanenvironments and aided in design concept generation. Proposed design concepts were compared by theteam, presented to the client and iterated until the design shapes to the client’s ideal perception. Onceapproved, possible prototypes of the design were then created. A final cost analysis and design conceptwas created and presented to the client for final decision making. The work process diagram was createdand shown in Figure 6.8
Figure 6. Work Process Diagram3.3.3 Functional ModelThe functional model is a breakdown of the process
"The scope of this project is to design, build, and test a fan-filter unit (FFU), a curtain clean room area, and a laminar flow hood to help establish sterile manufacture capabilities. The flow hood (2'x 4') and clean room (4'x 6') must have the ability to be disassembled and reassembled, clean and sterilized, and portable."
