SideMount Machine Closed-Circuit Rebreather
Contents
1. 2 Figure 26 MSR Dromedary Bags Two counterlungs are used in this design one on the exhale side and one on the inhale side This separation allows for an increase in dwell time which indicates that the gas traveling through the loop moves slower to allow the scrubber material to work more efficiently Each counterlung is connected to the rebreather through a counterlung connection Figure 27 The MSR bag slides over the opening on the counter lung connection and is secured in place by the containing ring Black ring in Figure 27 The connections are constructed of schedule 40 PVC commonly used to transport drinking water 40 Figure 27 Counterlung Connection 6 1 4 Scrubber Of the two types of scrubber designs already identified as 1 1 and radial the axial with its proven efficacy and ease of design was eventually chosen for daily use over its counterpart rival The radial scrubber was finally ruled out because of lack of sufficient proven research that it is better or more efficient than the axial scrubber The dimensions of the acknowledged radial scrubber evolved from US Navy Scrubber recommendations and the commercial scrubber design of the Kiss Classic The Navy recommendation for scrubber design for a re breather with a three hour duration has the following requirements 11 amp 12 e Cylindrical Tube Design with minimum of inch wall thickness e Length to Diameter Ratio 3 02 e Scrubb2. 2 L Surkace supplied Divme sn energie 2 2 1 Open Circuit Diving ans kg an lin 22 EG CADE UIE Diving ass ee 3 Purpose of Closed Circuit Re bre ther ee 3 1 Military Diving a a 3 2 Civilian Divine nase 4 Functionality of Closed Circuit Rebreather Breathins Loop energie 4 11 GET 41 23 Breathing HOSES Re F eks 4 1 4 Carbon Dioxide Serubber areas 4 2 Gas u a EEE EERE TAE E a aE 4 3 PPOs Monitoring Sysiemn una ee mens ebene DoE sisting Technology uses ea Kiss Classic an ee ira S2 EEE NE CORE SMN NESE TORP EST 6 Desi MOTE aS 6 1 Breathing Loop eisen bush HA Moe 6 12 Breatiins POSES avd STG 6 1 3 Counterlungs uses Ban ses bl DEE u aa ee ee er 615 Plow GS sea G2 Gas SOUTCES LAR 6 3 PP0s Monitoring nee 6 4 Ser bber Head Geis etd ai 6 5 Counterlung Housing sun een 49 TT 51 Ga R See 55 9 Recommendations Tor Future susanne lan 56 9 1 Modifications name ke inurl 56 TET Mie 56 Ter 56 92 Addons apene eda redi 57 9 3 Scrubber Testing uses Bei a a 57 REE Ne 58 Appendix Timeline of the SMM en 60 Appendix SMM Specifications 61 Appendi
3. Figure 12 Over the Shoulder Counterlungs 9 Back mounted counter lungs give the diver the ability to have his or her chest area clean and clear of obstacles since the counter lungs are mounted in case behind the diver usually situated higher on the shoulder blades The disadvantage of this type of counter lung is the increase breathing effort resulting from the differences in hydrostatic pressure counter lungs placement compared to the ordinary functioning of diver s lungs 23 Figure 13 Back mounted Counterlungs 5 4 1 4 Carbon Dioxide Scrubber The scrubber removes the carbon dioxide that the diver exhales into the loop during his or her exhalations The gas moves into the scrubber canister advances through the scrubber material and next transports back out into the breathing loop There are two types of scrubber designs the axial scrubber and radial scrubber Figure 14 Both remove carbon dioxide from the diver s exhaled gas but the way the gas flows through the scrubber median differs An axial scrubber is designed to have the breathing gases move from top to bottom or vise versa through the scrubber median 4 Conversely the design of a radial scrubber is to have the breathing gas move from the middle to the outside or vise versa through the scrubber material 4 There are divergent claims by different divers about the radial scrubber having an advantage over the axial scrubber but to date there has not
4. drops below the diver s required set point rebreather will automatically add more oxygen to the breathing loop through an electronic solenoid The rEvo is also equipped with DSV mouthpiece and manual add buttons for oxygen and diluent gas addition As well as an ADV two independent PPO2 displays and Heads Up Display HUD are graphically shown in Figure 19 A Heads Up Display is a small multi colored light display and it is attached to the mouthpiece and allows the diver to monitor the contents of the breathing loop by viewing the lights Depending on the colors and or blinks the signal notifies the diver of the loop s contents as well as permitting the diver s hands to be free to work The two displays each show a reading from different oxygen sensor and the HUD shows the third oxygen sensor 6 Figure 19 rEvo PPO2 Displays amp HUD 6 31 5 3 Megalodon The Megalodon Meg Rebreather is an electronic CCR and just as the other rebreathers previously mentioned it comes with an ADV HUD and manual add buttons for gas addition and DSV This Meg unit differs from the Kiss and rEvo since it has over the shoulder counterlungs and the entire device is built around the canister Figure 20 which incidentally holds the scrubber The standard scrubber for the Meg is an axial design it holds about five and half pounds of scrubber median and is placed inside the canister 7 Figure 20 Megalodon Canister with mounting
5. The monitoring system consists of at least three oxygen sensors which are usually mounted in the main rebreather canister The items are then wired to an electrical display outside of the CCR and secured inside a waterproof housing especially designed to allow the diver to monitor the oxygen levels 26 5 Existing Technology Currently the closed circuit rebreather market has over dozen different rebreather models being produced but all are considered back mounted rebreathers back mounted rebreather is a unit that is worn on the diver s back in similar manner that a hiker would wear a backpack whereas an open circuit diver would wear a set of doubles Side Mounted Rebreathers are not currently available commercially and although there are a few companies doing research and development the methodology is still in its infancy as far as commercial units are concerned The back mounted units with good track records for dependable functionality currently available on the market are the Kiss Classic the rEvo the O2ptima and the Megalodon These exceptional units are also being used to push the limits in recreation diving and in technical professional exploration 5 1 Kiss Classic The Kiss Classic Rebreather was designed with the philosophy of keeping the device simple This closed circuit rebreather is a buffered manual control unit and it is mixed gas capable This basic description means that the unit has a constant flow of
6. and effort making sure that their scrubber is properly installed The second big difference in the O2ptima compared to other already described re breathers is its scrubber location Unlike the other systems Dive Rite s scrubber is located behind the diver s neck in what constitutes a horizontal position This unique design makes it nearly impossible for water to come into contact with the scrubber in the event of a flood 8 34 Table 3 Comparison Overview Rebreather Kiss Classic rEvo Megalodon Optima Counterlung Back mounted Back mounted Front Mounted Front Mounted Manual Yes Yes No No Electroinc No Yes Yes Yes BOV Yes No No No ADV Yes Yes Yes Yes Oxygen MAV Yes Yes Yes Yes Diluent MAV No Yes Yes Yes Scrubber Type Axial Axial Axial Axial PPO2 Displays Yes Yes Yes Yes HUD No Yes Yes Yes Dimensions 21 x 14 8 54cm x 36cm x 20cm 25 x 15 x 8 64cm x 38cm x 20 cm 35 NA 25 x 13 x 7 64cm x 33cm x 18cm 6 Design Outline The SideMount Machine SMM as introduced in these thesis by the author follows the same philosophy of keeping it simple as the Kiss Classic does This product is a rebreather system that is a fully closed circuit mixed gas rebreather promoting constant mass flow oxygen contro
7. gas valve since the initial design of the SMM does not have an automatic diluent valve This BOV mouthpiece has a proven record for functionality and reliability Figure 24 Kiss Classic BOV 6 1 2 Breathing Hoses The breathing hoses Figure 25 for this Kiss Classic design are the standard rubber corrugated rebreather hoses used on most rebreathers today The inner diameter of these hoses is 1 5 inches and the length will be 22 inches for the inhale side and 17 inches for the exhale side The later adjusted water use length 38 was chosen after pictures showed excess hose utilization with 22 inch hose on the mouthpiece s exhale side therefore after experimentation 17 inch hose was constructed and tested ultimately proving to be more suitable choice The breathing hoses float when in water and three stainless steal hose weights are placed on each hose to weigh them down and coincidentally increase the comfort of the mouthpiece Figure 25 Breathing Hoses 6 1 3 Counterlungs The counterlungs employed for the SideMount Machine Rebreather are MSR Dromedary Bags Figure 26 that can easily be purchased from any hiking or camping store The bags also come in variety of sizes to accommodate the specific lung volumes of different sized divers These bags are designed to hold drinking water hence they work great for counterlungs and are easy to clean eliminating any likelihood of egregious bacterial growth 39
8. inside an aluminum housing and attached to the CCR s head The Kiss Classic is equipped with an automatic diluent valve ADV which enables the diver to add diluent gas into the breathing loop without having to press any additional buttons The ADV as shown in Figure 17 is located in the head of the rebreather near the right side 5 29 5 2 The rEvo is mixed gas fully closed circuit rebreather with back mounted counterlungs The unit comes standard with an axial scrubber Figure 18 but has an uncommon dual canister design This selfsame dual design splits the scrubber material into two separate canisters instead of possessing just single canister scrubber like most other rebreathers sold on the market It is claimed by the manufacturer that the dual design allows for better performance of the scrubber material and the industrial specifications simultaneously increase the device s safety Figure 18 rEvo Dual Scrubber 6 The rEvo CCR can be set up in three different ways as a manual as a hybrid or as a fully electronic rebreather 6 Setting up this unit to work manually the device operates like the Kiss Classic Rebreather when set up to run electronically the rebreather controls and monitors everything in the system 30 automatically 6 The hybrid is the most unique feature of the rEvo When using the hybrid method the rEvo has constant flow of oxygen like the Kiss Classic does but if the
9. is compatible with either air or trimix as diluent gas 13 cuft tanks are recommended Figure 10 Basic CCR Schematic 3 4 1 1 Mouthpiece Two types of mouthpieces commonly found on Closed Circuit Rebreather are the Diver Surface Valve DSV and the Bailout Valve BOV and depending upon which type the unit is equipped the mouthpiece s identity is determined The DSV Figure 11 operates with the use of two position lever on the mouthpiece either indicating open or closed When the lever is in the open 20 position the loop is open and the mouthpiece must be in the diver s mouth When the lever is in the closed position the loop is shut and sealed from the surrounding environment The BOV Figure 11 has dual purpose functionality it acts as a DSV but has a second stage built into it as well This capacity allows the diver to switch from closed circuit to open circuit by closing the DSV therefore closing the loop and opening up access to open circuit via the second stage regulator Figure 11 Dive Surface Valve 9 amp Bailout Valve 5 4 1 2 Breathing Hoses The breathing hoses are attached to the mouthpiece and allow the exhaled gas from the diver to travel into the counterlung scrubber The gas then travels back to the diver when inhaling from the scrubber the gas next travels to the counterlung and then passes back to the mouthpiece The type of hose that is standard throughout th
10. rEvo PPO2 Displays 2 22 A222222 2a 31 Figure 20 Megalodon Canister with mounting hardware 2 222 222 32 Figure 21 Megalodon Head with Displays amp Head connected to Canister 33 Figure 22 Dive O2ptima Rebreather 34 Figure 23 SMM Cutaway VIEW sense Ene 37 Figure 24 K ss Classic BOW Ess seele 38 Figure 25 Breathing a ein a 39 Figure 26 MSR Dromedary Bags nannte 40 Figure 27 Counterling Connection un ea 41 Figure 28 Scrubber C nister sen sanken 43 Figur 29 Serubber Basket een en ae 44 Figure 30 Ist Stage with blocking plug amp 45 Figure 31 Oxygen Manual Add 46 Figure 32 Sensor Plate with Oxygen Sensors 1 1 41 47 Figure 33 PPO2 Display External 48 Fig re 94 Serubber Head een een ak 49 Figure 35 Counterlune aussen 50 Figure 36 Non Trimmed amp Trimmed 1 Introduction The history of professional diving can be traced back more than five thousand years Man s relationship with diving is firmly rooted in maritime commerce in military operations and in salvage work 1 There has always been an aspiration to expand underwater frontiers through exploration research and development of new gear and diving techniques 1 Original equipment de
11. the first practical diving dress 1 The first practical diving dress is accredited to Augustus Siebe who creatively modified the helmet of Deane s diving dress by adding a collar to fully seal the helmet around the diver s neck Figure 5 Siebe also added an exhaust valve to the helmet to vent excess gas Siebe s improved diving dress is the direct ancestor of the United States Navy s MK V standard deep sea diving dress 1 Figure 5 Augustus Siebe s Diving Dress 1 In 1905 the United States Navy designed the MK V Diving helmet which was basically Siebe s Diving Dress with some added safety modifications The MK V Diving helmet was used until February 1980 the upgraded model featuring only a few small modifications from the helmet s initial debut in 1905 The MK 12 Surface Supplied Diving System Figure 6 succeeded the MK V and this new unit was replaced by the MK 21 Figure 6 in December 1993 These improved units were minor upgrades to their predecessor with certain aforementioned advances in construction materials to make them lighter and more efficient Figure 6 US Navy MK 12 amp MK V 1 2 2 SCUBA The development of diving equipment engineered by John Deane Augustus Siebe and other early lesser known contributors gave men the ability to work underwater for extended time periods Despite this obvious progress work was still limited by the need of surface vessel to support the divers better so
12. the scrubber lid in to the scrubber canister it should slide down the center tube until it is about 1 1 8 inch from the top of the center tube Place the scrubber head on top of the scrubber canister aligning the hooks on the scrubber head with the latches on the scrubber canister Connect the 82 latches and press down the latches of opposite sides at the same time to apply pressure evenly Counterlung Case Slide the counterlung case over the low pressure hoses attached to the MAV and down over the counterlungs Make sure to feed the oxygen first stage thru the hole on the side of the counterlung case and be careful not to pinch the counterlungs between the case and scrubber head Slide the counterlung case until the bottom hose clamp is in the middle of the latches on the scrubber canister Tighten the bottom hose clamp securing the counterlung case to the scrubber head and locking the latches down preventing them from accidently opening 83 DSV BOV amp Loop Hoses With a lint free cloth clean the inside ends of the loop hoses and outer edges of the DSV BOV Slide a stainless steel hose clamp over one end of the loop hose and slide the hose over one end of the BOV Repeat this step for the second loop hose and other side of the BOV Slide the hose clamps to the end of the loop hoses closest to the BOV and tighten down Slide the remaining two hose clamps over each loop hose The loop hose coming from the right of t
13. 79 that the MK 15 closed circuit rebreather was manufactured and implemented into the US Navy Diving Program The MK 15 is constant oxygen partial pressure rebreather whereby the oxygen content is controlled at constant rate and is monitored by an oxygen sensor This 14 unit is used when missions deeper than an ordinary oxygen rebreather will allow 1 15 3 Purpose of Closed Circuit Rebreather 3 1 Military Diving The United States Navy began using closed circuit rebreathers for combat missions during WWII The U S Operational Swimmer used the LARU in special missions during wartime This CCR gave the diver the advantage of being bubble less and stealthier than swimming with traditional open circuit scuba Today the U S Navy has two separate groups of combat swimmers Explosive Ordnance Disposal EOD and Navy Air and Land SEAL special warfare teams Both groups take advantage of the CCR because of the overall silence and the bubble free surroundings these units offer 1 This extraordinary functionality gives the combat swimmers the ability of approaching enemy targets undetected during combat missions as well as increasing safety when working with explosives which may detonate due to immediate turbulence caused by the bubbles of an open circuit scuba system 3 2 Civilian Diving The human urge to explore unknown areas can be dated back as far man s fascination with the unknown existed As technology has
14. E FLORIDA SCRUBBER BASKET BOTTOM DRAWN BY CHRSTINA LUCAS SECTION OCTOBER 2010 SCALE 0 500 SHEET I 68 ANTHONY TEDESCHI MELBOURNE FLORIDA SCRUBBER BASKET 110 DRAWN Br CHRISTINA LUCAS SECTION OCTOBER 2010 SCALE 0 500 SHEET I 69 ANTHONY TEDESCHI MELBOURNE FLORIDA SCRUBBER CANISTER DRAWN BY CHRISTINA LUCAS SECTION OCTOBER 2010 SCALE 0 300 SHEET 70 ANTHONY TEDESCHI MELBOURNE FLORIDA SCRUBBER CANISTER BOTTOM DRAWN BY CHRISTINA LUCAS SECTION OCTOBER 2010 SCALE 0 500 SHEET 71 Appendix 2 Circuit Schematic Schematic dlagram of the three Mr a an un display three sensar PPO2 boord 3 5 pe 1 4711700 72 Parts List Appendix F User Manual 1 Counterlung case either 6 or 8 inch with utility hook rubber connection boot and rear connection attachment I Scrubber Head with counterlung connections amp tubing attached 2 Counterlungs selection from 2 or 4 liter I Oxygen first stage with delrin plug OPV and HP button gauge I Oxygen Addition System which includes Already Assembled 1 LP hose with orifice I Checkvalve 1 Y block manifold I Manual Add Valve I Quick Disconnect Check valve 1 LP hose with Quick Disconnect I LP hos
15. PO2 display were designed constructed and tested Watertight housing for PPO2 displays designed and constructed Phase 2 testing of the SMM completed 60 Appendix SMM Specifications Table 3 SMM Specifications Weight w a full steel low pressure 1283 Lb tank and full scrubber Dimensions Height x Diameter 29 x 8 Constant Mass Flow Yes Manual Add Valve for Oxygen Yes Trimix Compatible Yes Depth Rating 300 feet saltwater Scrubber Absorbent 8 lbs 61 Appendix Pro Engineer Renderings ANTHONY TEDESCHI MELBOURNE FLORIDA SCRUBBER BASKET BOTTOM DRAWN BY CHRISTINA LUCAS SECTION OCTOBER 2010 SCALE 0 900 62 ANTHONY TEDESCHI MELBOURNE FLORIDA SCRUBBER BASKET LID OCTOBER 2010 SHEET I 63 ANTHONY TEDESCHI MELBOURNE FLORIDA SCRUBBER CANISTER DRANN BY CHRISTINA LUCAS SECTION OCTOBER 2010 SCALE 0 350 64 ANTHONY TEDESCHI MELBOURNE FLORIDA SCRUBBER CANISTER BOTTOM DRAWN BY CHRISTINA LUCAS SECTION OCTOBER 2010 SCALE 0 700 65 ANTHONY TEDESCHI MELBOURNE FLORIDA SCRUBBER HEAD DRAWN BY CHRISTINA LUCAS SECTION OCTOBER 2010 SCALE 0 500 SHEET I 66 Appendix D Technical Drawings ANTHONY TEDESCHI MELBOURNE FLORIDA SCRUBBER HEAD DRAWN BY CHRISTINA LUCAS SECTIGN OCTOBER 2010 SCALE 0 500 SHEET 67 ANTHONY TEDESCHI MELBOURN
16. September 1 2010 from http www therebreathersite nl Kiss Rebreathers Retrieved September 1 2010 from http www kissrebreathers com kissclassic html rEvo Rebreathers Retrieved September 2 2010 from http www revo rebreathers com en home 58 7 8 9 10 11 12 The Megalodon Rebreather Retrieved September 2 2010 from http www customrebreathers com meg html Dive Rite Retrieved September 2 2010 from http www diverite com Rebreather World Retrieved September 5 2010 from http www rebreatherworld com Golem Gear Retrieved September 6 2010 from http www golemgear com Goodman LCDR M W Carbon Dioxide Absorbtion Systems for SCUBA 1 Quantitative Consideration of Design and Performance and Performance of Cylindrical Cansisters U S Navy Experimental Diving Unit January 15 1965 Huseby H W S amp Michielsen E J Carbon Dioxide Absorbent Evaluation and Canister Design amp Letter Report U S Navy Experimental Diving Unit November 6 1959 59 Appendix Timeline of the SMM August 2010 September 2010 October 2010 November 2010 Initial rebreather designs sketched and Counterlung Connections designed constructed Proposal of Design for the SideMount Machine Closed Circuit Rebreather Completed Scrubber design finalized and SMM was constructed Initial testing was conducted and modifications made Electronics for P
17. SideMount Machine Closed Circuit Rebreather by Anthony Tedeschi Jr Bachelor of Science Ocean Engineering Florida Institute of Technology May 2008 thesis submitted to Florida Institute of Technology in partial fulfillment of the requirements for the degree of Master of Science in Ocean Engineering Melbourne FL January 2010 2011 Anthony Tedeschi Jr All Rights Reserved The author grants permission to make single copies We undersigned committee hereby approve the attached thesis SideMount Machine Closed Circuit Rebreather by Anthony Tedeschi Jr Stephen L Wood Ph D P E Assistant Professor Ocean Engineering Major Advisor Jonathan Shenker Associate Professor Biological Science Department Geoffrey W J Swain Ph D Professor Ocean Engineering and Oceanography George A Maul Ph D Professor amp Department Head Department of Marine and Environmental Systems Abstract Title SideMount Machine Closed Circuit Rebreather Author Anthony Tedeschi Jr Major Advisor Stephen L Wood Ph D P E new type of mixed gas closed circuit rebreather has been developed to give a scuba diver the ability to access smaller passages in an underwater cave or shipwreck It may also be used as a back up system to a traditional rebreather setup by allowing the diver to carry less backup scuba cylinders therefore increasing the diver s safety The SideMount Machine SMM closed circuit
18. WII in France Jacques Yves Cousteau and Emile Gagnan achieved a breakthrough in open circuit scuba They improved on Rouquayrol s Demand Regulator and subsequently upgraded their predecessor s work with high pressure air tanks to create the first open circuit scuba unit commonly known as the Aqua Lung Figure 7 Their dual effort was a combination of years of progress and blending the work of different developers At the termination of WW II the Aqua Ling quickly became a huge commercial success and it is still the most widely used diving equipment 1 11 Figure 7 Aqua Lung 2 2 2 Closed Circuit Diving The basic closed circuit rebreather or oxygen rebreather uses tank of one hundred percent oxygen to supply breathing bag into which diver takes breath The exhaled gas from the diver is then re circulated through chemical filter with the purpose of removing carbon dioxide from the exhaled gas The oxygen metabolized by the diver is efficiently replenished from the tank of pure oxygen carried by the diver The first practical commercial closed circuit system Figure 8 was developed between 1876 and 1878 by Henry A Fleuss This closed circuit scuba system consists of copper tank containing pure oxygen and watertight facemask having a breathing bag attached The early models of the Fleuss device controlled oxygen addition with hand valve which the diver controlled Development of the 12 Fleuss system co
19. allow after market PPO2 displays and dive computers to be integrated within the system 9 2 Additions If used either as decompression rebreather or as bailout rebreather the unit needs an automatic diluent valve ADV and an over pressurization valve OPV The ADV will allow diluent gas to be automatically added to the loop as the diver descends obviously preventing the rebreather from imploding Once the diver begins his or her ascent back to the surface the gas in the loop expands and an OPV is then needed to vent the excess gas Since the current SMM can be used as a primary rebreather the diver can add and remove gas as needed during either his or her descent or ascent 9 3 Scrubber Testing To be profitably sold in the commercial marketplace the SideMount Machine Rebreather will need additional laboratory testing This required testing should be objectively conducted by independent laboratories and should decisively assess maximum scrubber duration capability This responsible testing would simulate a diver s underwater activities under extreme submerged swimming conditions 57 1 2 3 4 5 6 References United States Navy U S Navy Diving Manual Revision 6 Naval Sea Systems Command April 2008 Technical Diving International Intro 10 Tech 2009 Advanced Diver Magazine Retrieved September 1 2010 from http www advanceddivermagazine com Rebreathers Worldwide Retrieved
20. ary display and the backup display The oxygen sensors are mounted to a sensor plate Figure 32 which is housed in the head of the CCR and the indicator reads the oxygen content before it travels to 46 the inhale counterlung The wires pass through the top of the head and each circuit is attached to separate waterproof connectors Figure 32 Sensor Plate with Oxygen Sensors The external electronics consist of two separate displays encased in waterproof housings Figure 33 Each display shows the three separate oxygen sensor readings by converting the milli volt reading the oxygen sensor outputs into a partial pressure oxygen reading This transfer gives the unit redundancies for the readings and using analog circuitry it adheres to the philosophy of the SMM design in keeping it simple 47 Figure 33 PPO2 Display External Electronics 6 4 Scrubber Head The SMM s scrubber head Figure 34 is the rebreather s core it houses the three oxygen sensors two through holes for both exhale amp inhale counterlungs as well as containing the scrubber canister s connection point The delrin head was machined from a six inch 15 24 cm rod stock by a computer numerical control CNC machine There are two 1 inch 2 54 cm schedule 40 PVC tubes coming from the top of the scrubber which are connected to the counter lung connections These tubes allow the gas to flow from the diver s mouth through the system an
21. been any convincing published evidence to prove this speculation and the argument continues to be dominated by personal opinion 24 Figure 14 Axial 7 and Radial 10 Scrubbers The scrubber median used in rebreathers is soda lime and consists of the following components Calcium hydroxide water 2 Sodium hydroxide NaOH and Potassium hydroxide KOH The reaction takes place along a front which is the cross section of the scrubber canister When the exhaled carbon dioxide passes along the front of the soda lime it reacts and is converted to calcium carbonate 4 2 Gas Source All mixed gas Closed Circuit Rebreathers have two gas supplies to function properly The first gas supply is oxygen providing the diver with the needed oxygen that is removed from the loop after every breath is taken The other gas called diluent is usually air or some kind of trimix Trimix is a diving gas used 25 with combination of nitrogen oxygen and helium This gas is meticulously fed into the rebreather as diver moves deeper in the water column and because of the increase in surrounding pressure the diluent is added to provide the recipient with an adequate volume of gas to fill their lungs when taking a breath 4 3 PPO Monitoring System The or Partial Pressure of Oxygen monitoring system measures the PPO in the rebreather loop and then the readout is visually displayed to the diver
22. by supplying his divers with fresh air using series of weighted inverted buckets Then in 1690 Edmund Halley combined the diving bell along with series of weighted inverted buckets allowing him to adequately replenish the diving bell with fresh air shown in Figure 3 1 Figure 3 Edmund Halley s Diving Bell 1 s maritime commerce expanded so did the shipwrecks scattering the coast caused by storms collisions and navigational errors This newfound phenomenon caused greater need for diving dress that provides the explorer with better mobility and efficiency John Lethbridge developed completely enclosed one man diving dress Figure 4 Wearing this diving dress an ambitious diver could achieve depth of approximately sixty feet and stay underwater for almost forty minutes The diver was able to work efficiently for longer duration but the new equipment had the same disadvantage as the diving bell surface support vessel was needed to deploy and maneuver the diver 1 Figure 4 Lethbridge s Diving Suit 1 At the turn of the 19 century hand operated pump was developed and this machine was capable of delivering abundant air under pressure to a diver In 1828 Deane s Patent Diving Dress was developed it consisted of a heavy suit helmet with viewing ports and a hose to allow surface supplied air to the diver While Deane s Diving Dress was a breakthrough in Surface Supplied Diving it was not
23. d then back to the diver 48 Figure 34 Scrubber Head 6 5 Counterlung Housing The counterlung housing Figure 35 of this rebreather is constructed from schedule 40 PVC and encloses the counterlungs to protect them from the surround environment The housing slides over the two counterlungs and a rubber coupling secures the counterlung housing and rebreather head A small stainless steel hook is mounted to the top half and acts as an attachment point for the CCR to the diver Another extra large bolt snap is secured to the middle of the rubber coupling and is the attachment point for the bottom of the SMM 49 Figure 35 Counterlung Case 50 7 Testing certified closed circuit rebreather diver tested the efficacy of the SideMount Machine Rebreather Completed in two phases the obtained results were compared to comparable available commercial unit The first testing phase was to assure the work of breathing and to assure that the design was within reason constructed correctly to prevent leakage as well as to confirm that the PPO2 displays functioned properly The second testing phase was performed in order to utilize the unit in normal diving conditions and thus confirm the results of phase one testing The method of testing can be interpreted in the following table provided 51 Table 4 Phase 1 Testing Test Purpose Positive amp Negative Pressure Test To make sure the re breather was
24. developed and more 16 people have wandered the globe remote areas of exploration are becoming fewer These unexplored areas of the underwater world now exist at much deeper depths than before and or in more remote locations The functionality of a closed circuit rebreather allows for easier access to more difficult dive sites because the device requires less gas and can be used for a longer duration than traditional open circuit gear Since the rebreather recycles the gas used by the diver it is lighter than an open circuit scuba setup This important characteristic allows for easier mobility when traveling greater distances to explore in remote locations Transportation to arrive at given destinations may range from small plane access slow donkey passage or having to walk through a dense jungle The first major advantage of the CCR is that it is not depth dependent its operational duration does not change whether the diver is at twenty feet or two hundred and twenty feet This significant advantage again benefits the diver by allowing him or her to descend deeper into a sea or lake or stay underwater longer than traditional scuba gear permits The second advantage of the Closed Circuit Rebreather is that a diver can perform many long or deeper dives again and again using the same rebreather The traditional open circuit diver requires multiple sets of tanks and decompression tanks The third practical advantage of a CCR is the absence of bubble
25. e industry is composed of corrugated rubber The object s 21 length ranges from approximately seven inches to twenty two inches depending the particular rebreather setup and design 4 1 3 Counterlungs Counterlungs on a rebreather act as external lungs for the diver and they should match as close to the diver s tidal volume as possible When diver exhales into the loop the exhaled breath automatically fills the exhale counter lung then the gas travels through the scrubber and next back into inhale counter lungs This process allows for the gas in the loop to sufficiently dwell causing an improved mix with the new gas added to the loop thus providing the scrubber more time to work The two main setups for counterlungs on rebreather are the over the shoulder counterlung Figure 12 and the back mounted counterlung Figure 13 The over the shoulder counterlungs connect to the diver s harness and come to rest in front of the diver s body This specific symmetry offers a more propitious hydrodynamic gas flow inside the loop in horizontal trim position Consequently the apparatus allows for less demanding breathing effort The disadvantage of the over the shoulder counter lung is its vulnerability to sharp objects such as the masts of shipwrecks or cave ledges The counter lungs can also cause the diver s chest to be cluttered making it more difficult to clip and unclip necessary accessories to their harness 22
26. e three o rings with silicone grease and be sure all o rings are in proper working order The smaller diameter and thicker o ring is used to secure the sensor plate and does not need to be lubricated 76 Scrubber Head w 1 O ring Installed Scrubber Center Tube with O ring Installed Oxygen Sensors Screw each of the three oxygen sensors MaxTec Max 12 in to the sensor plate until snug DO NOT OVERTIGHTEN 77 Connect each oxygen sensor to the molex connector in the scrubber head and be sure to connect the numbered connector to the corresponding sensor numbered on the sensor plate Slide the sensor plate into the scrubber head making sure the top of the sensors are closest to the top of the scrubber head Be careful not to pinch any wires or to jam the sensors against the top of the scrubber head Slide the sensor plate o ring over the outside of the scrubber head center tube securing the sensor plate in place 78 Oxygen Addition System The SMM s oxygen addition system comes completely assembled except for the low pressure hose coming from the outlet side of the manual add valve MAV Using a 5 8 inch thin wall wrench hold the fitting attached to the elbow coming from the scrubber head to keep from breaking the epoxy seal Finger tighten the end of the low pressure hose to the fitting then using an 11 16 inch wrench snug the hose down MAKE SURE NOT TO BREAK THE EPXOY SEAL Allow the low pres
27. e to connect to Scrubber Head 1 Scrubber Canister 1 O ring Set includes 2 Scrubber Canister O rings 252 1 Scrubber Center Tube O ring 125 o 1 Oxygen Sensor Holder 323 2 Loop hoses 17 inch amp 22 inch 6 SS ballast Rings 4 Small hose clamps 1 Bailout Valve mouthpiece with Quick disconnect 1 Diluent Low Pressure Hose 36 inch 2 PPO2 Displays with batteries Not Included 3 Oxygen Sensors 12 Diluent Bailout Regulator Diluent Bailout Tank Oxygen Tank BCD Harness System 73 Schematic NEID AX Omm D 74 Components A Dive Surface Valve DSV Bailout Valve BOV B Exhale Counterlung 2 or 4 liter C Carbon Dioxide Scrubber D Inhale Counterlung 2 or 4 liter Oxygen tank with plugged first stage regulator F Oxygen Manual Add Valve with Orifice G Scrubber Head Houses three Max 12 Oxygen Sensors H Scrubber Canister I Counterlung Case 6 or 8 inch J PPO2 Displays Two independent systems each read all three oxygen sensors 75 Installation Assembly O rings Included with your SideMount Machine CCR are four o rings The two large diameter o rings get placed in the two o ring grooves on the scrubber head The single smaller diameter and thickness o ring top left in picture is placed inside the center tube of the scrubber head Be sure to wipe out the o ring grooves with a lint free cloth making sure they are free of dust and or debris Lubricate th
28. ely introduced into the system via an orifice valve Figure 30 at a gas flow rate just under the diver s metabolic oxygen consumption This practice is done by inserting a blocking plug into the oxygen thus consummating first stage Figure 30 and the precise mixture keeps the intermediate pressure from changing with depth in turn keeping the flow of oxygen constant at any depth Figure 30 1st Stage with blocking plug amp Orifice The oxygen can also be added to the loop using a manual add valve in case the orifice valve is not providing enough oxygen therefore the diver can simply add optimal gas into the system by pressing a button Figure 31 45 Figure 31 Oxygen Manual Add Valve The diluent gas will be added to the system with the mouthpiece via the bailout valve As the loop volume decreases the diver will switch the BOV to the open circuit position inhale and next switch the BOV back to closed circuit adjustment and then exhale back into the loop 6 3 PPO Monitoring System The only electronics evident in the SMM s rebreather design is present inside the partial pressure oxygen monitoring system This system consists of two sections the internal electronics which are housed inside of the breathing loop and the external electronics which will be attached to the diver The internal electronics consist of three oxygen sensors and each sensor is connected to two different wires which are connected to the prim
29. er length 12 28 inches 31 19 cm 41 Scrubber diameter 4 06 inches 10 31 cm Bottom spacing water trap minimum of 1 18 inches 2 99 cm e Scrubber Endplates Non corrosive nonmagnetic materials o Rim between 0 39 to 0 59 inches 0 99 to 1 49 cm o Hole openings less or equal to 0 78 inches 1 98 cm amp at least 35 open area The Kiss Classic scrubber has a rated duration of three hours and has the Dimensions as follows Cylindrical Tube Design with inch 0 63 cm wall thickness Length to Diameter Ratio 2 39 e Scrubber length 11 25 inches 28 57 cm e Scrubber diameter 4 7 inches 11 93 cm The scrubber design for the SMM Figure 23 took into account the Navy recommendations the Kiss Classic design and finally material availability to produce scrubber with the following dimensions Cylindrical Tube Design with inch 0 63 cm wall thickness Length to Diameter Ratio 2 55 e Scrubber length 12 inches 30 48 cm Scrubber diameter 4 7 inches 11 94 cm 42 The scrubber canister is constructed of gray cylindrical PVC tube and the bottom is permanently capped with a piece of solid delrin which is secured with PVC cement Figure 28 Scrubber Canister The scrubber basket Figure 29 is dropped inside the scrubber canister and the scrubber material will then be packed around the center tube filling most of the canister The end caps are made from delrin with a stainless steel mesh sc
30. er than on the back of a diver Figure 1 SideMount Machine CCR being worn by diver This added advantage gives the diver the option of using the rebreather as backup to his or her normal rebreather or to just wear the rebreather on one side and an open circuit bailout scuba cylinder on the subject s other side If using the SMM as a backup rebreather this innovative method allows the diver to carry less equipment than he or she traditionally would employ if only operating one rebreather For example if a diver were to dive to 200 feet for about 30 minutes he or she would need a minimum of four scuba cylinders for backup safety protection in case the rebreather were to fail Table 1 shows the amount of gas required for a traditional CCR diver compared to that of a diver wearing the SMM and Figure 2 demonstrates the difference in diver s profiles between the two setups Table 1 Gas Capacity Comparison Setup Gas Volume Required Traditional 171 ft SMM Bailout 29 ft SMM Bailout Setup Traditional Setup 3 29 16 Figure 2 Profile View of SMM setup vs Traditional Setup The option of wearing the SMM rebreather on the diver s side gives him or her the ability to access smaller cave areas or a deep shipwreck because the rebreather can be completely removed and replaced during a dive Unlike traditional rebreathers that mount on the divers back and cannot be removed during a dive With the options the Side M
31. g water into which the diver is immersed and the contained gas moves from start to finish in one continuous loop The process begins with a mouthpiece that the diver exhales air into The gas travels from the mouthpiece into a breathing hose and next into the exhale counter lung From the counter lung the gas travels into the carbon dioxide scrubber and then exits into the inhale counter lung From the 19 inhale counter lung the gas travels through breathing hose back to the mouthpiece the genesis from where the diver receives another breath DSV Dive Surface Valve Counterlungs 2 liter 4 liter or 6 liter Oxygen Manual Add Valve with 15 micron filter D Exhaust Valve Scrubber Canister approximately 6 Ibs 2 7 kg ADV Automatic Diluent Valve G Triple Sensor Well R22D Teledyne Sensors 2 Displays Three independent 2 displays Each with its own housing battery and sensor Bail out Second Stage The bail out second stage is Zz incorporated into the DSV switch from closed circuit to open circuit bail out simply close the breathing loop The bail out second stage is plumbed to the diluent tank NOTE the bail out second stage is for getting a sanity breath only Divers should carry a redundant bail out system for emergencies Oxygen Tank amp First Stage 13 cuft tanks are recommended Diluent Tank amp First Stage The Classic KISS
32. g for leaks and spent 15 minutes determining if the scrubber was operating appropriately for the designed time range Table 5 Phase 2 Testing Test Purpose Land Test Used the re breather on land to make sure it had been properly removing the carbon dioxide and ascertaining that the PPO2 displays were operating correctly Duration was 15 minutes Pool Test Continued the land test in the pool making sure that the CCR did not leak and verifying that the electronics had been working properly Duration 2 hour 53 After conducting the land test and pool test for Phase 2 the SMM CCR passed as it was expected to as can be seen in the table above The next step for testing of the SMM is to bring to a shallow 20 30 range open water type environment From there it would need to be incrementally tested on deeper and longer dives 54 8 Conclusion the diver s needs increase his purpose being either professional or recreational the necessity for smaller modular simpler and cheaper equipment evolves forward in the direction of more practical diving device applications The objective of creating the SideMount Machine rebreather is to provide an alternative safe and efficient type of diving equipment capable of offering all of the above listed features to either the experienced or amateur diver With this current contemporary design the SideMount Machine Closed Circuit Rebreather affords the diver the opp
33. hardware 7 The Megalodon s core is the head Figure 21 which holds the solenoid oxygen sensors batteries and electronics The three oxygen sensors are mounted in the head s middle inside a sensor carriage The head is attached to the top of the Meg s canister with the electronics and sensors being stored inside the canister shown in Figure 21 From the top of the head comes two separate wire cords 32 which connect to independent displays Figure 21 to allow the diver to monitor the breath loop levels 7 Figure 21 Megalodon Head with Displays amp Head connected to Canister 7 5 4 O2ptima The Dive Rite O2ptima Figure 22 is a fully closed circuit re breather and constant electronically controlled unit featuring built in decompression ability The equipment has over the shoulder counterlungs similar to the Meg s and has the same functionality such as DSV oxygen and diluent add buttons ADV three oxygen sensors and HUD 8 33 Figure 22 Dive O2ptima Rebreather 8 The biggest difference with the O2ptima re breather design is its use of an Extend Air cartridge for its scrubber The scrubber is still an axial design like the others but the scrubber median is sprayed onto permeable material Once dry it is rolled up and cut to fit inside the scrubber canister This adaptability allows the diver to have pre packaged scrubber advantage and it saves him or her valuable time
34. he BOV is attached to the exhale tube and the left side loop hose is connected to the inhale tube Do not over tighten the hose clamps and make sure the loop hoses are not twisted PPO2 Displays Connect the PPO2 display following the aftermarket PPO2 display s instructions Positive Negative Test With everything connected the SMM has to be tested for leaks by conducting Negative and Positive pressure test Place the BOV in mouth making sure the lever is in the open position to breath off the loop Inhale through the mouth and exhale through the nose until you have created vacuum in the rebreather Close the switch on the BOV to keep the 84 vacuum allow it to sit for about minutes making sure no air enters the system Open the BOV switch to allow gas to enter in to the loop and place in to mouth Inhale thru nose and exhale thru mouth filling the loop with gas until full Switch the BOV back to the closed position and allow the rebreather to sit for about five minutes check to make sure the loop stays over inflated 85
35. l inside the system The SMM Rebreather can be used two ways The first implementation is as a primary unit worn on the diver s side similar to an open circuit side mounted cylinder but much smaller and less cumbersome Used this way the device allows the diver to have a smaller vertical yet wider profile in the water The SMM allows the diver access to smaller exploratory areas which under normal circumstances could not be reached with a traditional back mounted rebreather The SMM could also be used as a backup re breather worn easily as a Side Mount tank in addition to the diver wearing a traditional back mounted re breather The Side Mount Machine is easily accessed for use should the primary re breather fail 36 Figure 23 SMM Cutaway View 6 1 Breathing Loop 6 1 1 Mouthpiece The current rebreather market has variety of proven and remarkable functioning mouthpieces Mouthpiece selection is based on the diver s preferences and the type of diving he or she performs The SMM design uses a bailout valve mouthpiece which is the same that is used in the Kiss Classic s BOV as shown in Figure 24 37 The design decision to use the Kiss Classic s BOV mouthpiece was threefold The first apparent reason is increased diver safety Should the system fail while being tested the underwater participant could easily flip the switch and then be on open circuit scuba The versatile mouthpiece could also be used as an additional
36. lution was to have mobile self contained supply of air SCUBA or Self Contained Underwater Breathing Apparatus only existed in an abstract hypothetical realm This revolutionary diving method was theoretical for many years but its technology could not be developed because of limitations in contemporary air pumps and requisite containers to hold the compressed gas Scuba gradually evolved and separated into two distinct divisions Open Circuit Scuba Exhaled gas is vented to the surrounding environment and Closed Circuit Scuba Oxygen is filtered and re circulated back to the diver 1 10 2 2 1 Open Circuit Diving In 1866 Benoist Rouquayrol designed Rouquayrol s Demand Regulator The regulator adjusted the higher pressure from a container to a lower breathable pressure that the diver could use This regulator was the first necessary tool for an open circuit scuba system but containers to hold the desired breathing gas could not hold high pressure therefore the regulator was adapted for surface supplied diving It was not until 1933 that research on open circuit scuba development began again A French naval officer Commander LePrieur successfully built an open circuit scuba system using a compressed air tank Because his device did not have a demand regulator the diver had to constantly control the flow of air The lack of a demand regulator caused the diver to focus too much on air control and not enough on his mission 1 During W
37. ntinued with the addition of higher pressure oxygen cylinder and accompanying demand valve regulator 1 Figure 8 Fleuss Diving Apparatus 1 In the late 1940s Dr C J Lambarteen proposed the use of Mixed Gas Rebreather because oxygen becomes toxic to the human body on descents deeper than twenty feet This unique rebreather was based on the same concept as the oxygen rebreather but instead of inhaling pure oxygen the diver would have gas mixture containing nitrogen and or helium combined with heightened oxygen content This new mixture would allow for practical underwater usage beyond the depth range 20 feet of an oxygen rebreather Then in the early 1950s Dr Lambertsen introduced the FLATUS I which was semi closed circuit system that continually added small volume of mixed gas into to the breathing loop This 13 gas is then re circulated the carbon dioxide is removed and excess gas is vented out of the breathing loop During WWII the U S Navy enhanced and deployed the Lambertsen Amphibious Respiratory Unit LARU In the post war years that followed the LARU Figure 9 was replaced by the Emerson Lambertsen Oxygen Rebreather The Emerson unit was eventually substituted by the Draeger Lung Automatic Regenerator LAR V Figure 9 and is still used by US Combat Swimmers 1 Figure 9 Lambertsen Amphibious Respiratory Unit amp Draeger Lung Automatic Regenerator V 1 It was not until the beginning of 19
38. ortunity of accessing remote diving locations smaller areas in overhead environments such as caves or shipwrecks and or allow him or her the ability to safely and more efficiently dive deeper 55 9 Recommendations for Future In order to make the Side Mount Machine Closed Circuit Rebreather more acceptable commercial quality design few detailed adjustments to its construction have to be modified and or added 9 1 Modifications 9 1 1 Materials First designers must replace the PVC schedule 40 tubing and elbows with delrin tubing and elbows The inhale and the exhale tubes that connect to the head of the re breather should have threaded ends to allow them to be replaced should they ever be damaged and this particular modification will give them more secure fixture to the scrubber head counterlung connections can also be machined from delrin material instead of their current construction of PVC plumbing parts and their size profile can be satisfactorily decreased The stainless steel inlet for oxygen is secured with epoxy and it thus could be modified changed to be precisely threaded into the elbow 9 1 2 Electronics printed circuit board instead of breadboard currently used allows for professional look and its utilization reduces the size of the electronics 56 configuration Fisher connectors attached to scrubber head instead of the current waterproof connector can be initiated in order to
39. ount Machine offers the improvement would be very marketable not only to the serious exploration diver who is pushing the limits but also to the typical everyday amateur rebreather diver The goal of implementing the Side Mount Machine is not only to provide a reliable rebreather for divers but also to produce an affordable unit that will cost less than the three thousand plus dollar re breathers currently available in the marketplace 2 Background of Diving Equipment 2 1 Surface Supplied Diving Diving can be traced back more than five thousand years The adventurous individuals would use surface supplied air to harvest food coral exotic pearls sponges and would perform salvage work in up to one hundred feet of water depth These surface supplied units consisted of devices such as breathing tubes breathing bags diving bells and diving dresses 1 Breathing tubes were the most logical and easiest approach to supply diver with surface supplied air The diver would use hollow reeds or tubes long enough to reach the surface To go to greater depths the length of the breathing tube was extended however this extended tube approach is not feasible beyond three feet in depth due to the body s natural respiratory ability to counteract the external water pressure This pressure obviously increases as the diver descended deeper into the water column Table 2 1 Table 2 Depth amp Pressure Chart Depth Atmosphe
40. oxygen being added into the loop through a small orifice and the 27 concurrent flow rate is set to meet diver s oxygen requirements If the diver needs to add more oxygen to the loop the CCR is conveniently equipped with a manual add button Figure 15 which the diver simple presses to facilitate more oxygen entering the loop 5 Figure 15 Kiss Classic Manual Add Button 5 The partial pressure oxygen display Figure 16 for the Kiss Rebreather demonstrates three independent displays Each of the three displays maintains its own housing LCD screen battery and additionally each unit is connected to its own oxygen sensor O2 sensors are mounted in the head of the CCR This illustrated PPO display setup makes the unit completely redundant and highly unlikely to ever completely fail 5 Figure 16 Kiss Classic PPO2 Displays 5 28 The scrubber design of the Kiss Class is an axial flow canister Figure 17 which holds about six pounds of scrubber median The scrubber is attached to the head of the CCR Shown in Figure 17 and it is the black piece located above the scrubber This scrubber is rated for about three hours of use representing a flow of about one liter per minute of carbon dioxide expended by the diver 5 Figure 17 Kiss Classic Scrubber grey cylinder amp Head 5 This pictured rebreather is equipped with a BOV for its mouthpiece and has back mounted counterlungs The counterlungs are placed
41. re Absolute ATA Pressure oft 1 14 7 psi 1 BAR 33ft 10m 2 29 4 psi 2 BAR 66 ft 20m 3 44 1 psi 3 BAR 99 ft 30m 4 58 8 psi 4 BAR 132ft 40m 5 73 5 psi 5 BAR At the beginning of man s diving explorations the effects of pressure were not understood completely therefore designs such as breathing bags were impractical Breathing bags were initially designed with the idea of the diver carrying a bag of air Again issues involving greater pressure caused this primitive airbag design to be infeasible Another major issue with early breathing bag design was a practical way to sink the bag due to the bags buoyancy 1 The standard diving bell development started in 1500 and its adaptations continued into the 1800s The diving bell is an apparatus with a bell shape that has its bottom open to the water The early bells were strong tubs with weights attached to allow them to sink in a vertical manner The vertical positioning of the bell allowed air to be captured therefore supplying divers with sufficient air for hours rather than mere minutes These post medieval diving bells were not very maneuverable and required a surface ship to move and effectively deploy them The bell was either dropped over the work area or the diver would leave the bell for a short interval holding his breath and rapidly then returning to the diving bell for air 1 In 1680 William Phipps modified the rudimentary diving bell
42. rebreather has similar functionality as other commercial available rebreathers on the market such as Jetstam Technologies Kiss Classic InnerSpace Systems Megalodon rEvo and DivRites Optima rebreather The unique feature of this system is that the rebreather can be worn like a sidemounted scuba cylinder and can be completely removed by the diver and reattached underwater during a dive This thesis presents the design construction and field test of the SMM rebreather The closed circuit rebreather is designed with both an exhale and inhale iii counterlung to allow for greater dwell time of the gas traveling through the loop The SMM has a radial scrubber design to remove the carbon dioxide in the breathing loop and three oxygen sensors connected to monitoring system This enables the diver to see what the oxygen partial pressure is in the breathing loop to keep them alive This rebreather is also equipped with bailout valve to switch the from open circuit to closed circuit and to add diluent gas to the breather loop The oxygen addition system of the SideMount Machine is manual add valve which is connected to an oxygen tank and the diver presses the button to allow the gas to enter the breathing loop iv Table of Contents 1 Introduction 1 1 Purpose of SMM CCR es 2 Background of Diving
43. reen glued to act as a filter to efficaciously keep the scrubber material in place The end caps are designed to meet or exceed the stringent Navy recommendations listed above The center tube is constructed of schedule 40 one inch 2 54 cm PVC tube and one end is attached with PVC cement to a scrubber end cap 43 Figure 29 Scrubber Basket 6 1 5 Flow of Gas The gas flow starts from the diver s exhalation and travels through the exhalation side breathing hose From there the gas will travel to the exhalation counterlung It will then move from the counterlung traveling down the center tube of the scrubber When the gas reaches the end of the tube it mushrooms out from the center and flows back up through the scrubber material The gas then passes from the bottom to the top through the entire scrubber median When the gas reaches the top of the scrubber it travels past the oxygen sensors and into the inhale counterlung from there the gas flows through the inhale breathing hose side and back into the diver s mouth The gas is moved through the loop by the diver s exhale pushing the gas and inhale suction 44 6 2 Gas Sources For any closed circuit rebreather to function there needs to be way for both oxygen and diluent to be measurably added into the breathing loop The oxygen is added into the exhale side of the loop to promote it to travel through more than half the loop allowing it to mix evenly It is quantitativ
44. s this differentiation offers two benefits to the diver First the diver is virtually silent and second allows the diver to move closer to marine life without disturbing it e g documenting wildlife with photographs or video 17 Ostensibly the absence of bubbles shooting up from the diver is not at all evident His singular presence will have little or no an impact on an observable environment such as a pristine shipwreck where the possibility of the bubbles dislodging rust or silt has been satisfactorily eliminated When these vulnerable elements are disturbed the falling debris reduces the diver s visibility Better visibility allows for the diver to navigate more safely 2 18 4 Functionality of Closed Circuit Rebreather The Closed Circuit Rebreathers come in variety of shapes and sizes however when broken down into the most basic components the variations all contain the same fundamental parts and perform the same function which is to recycle the gas the diver uses 3 These fundamental parts can be classified into three sections the Breathing Loop the Gas Source and the Partial Pressure 2 monitoring system The only difference between the separate manufacturers designs is how the companies package these components into the CCR 3 In the figure below the basic CCR design and gas flow through a rebreather is shown 4 1 Breathing Loop A breathing loop on a CCR is a sealed oval apart from the surroundin
45. sealed not allow gas in escape or enter the system Duration 10 minutes Land Test Used the re breather on land to make sure it was properly removing the carbon dioxide Duration 1 5 hours Pool Test Used the re breather in the pool to check for any leaks not detected by the positive and negative test and to check the WOB of the re breather s design This check also allowed the test diver to determine how the unit had to be trimmed out Figure 36 Duration 20 minutes Dive Simulator Fed the electronics different millivolt reading to simulate change in PPO2 in order to check proper operation Phase 1 allowed the testing of the individual components and to confirm that the design had been done properly as to not having rebreather with an unacceptable high WOB The SMM did not have PPO2 electronics connected during Phase 1 testing therefore the breathing loop was flushed and fresh gas had been added about every ten to fifteen minutes This careful analysis was performed to make sure that the diver s PPO2 did not fall below 0 16 which logically and scientifically becomes unsustainable once it registers below that level All phase 1 tests were passed thus confirming that the SMM was both designed and functioning properly 52 Figure 36 Non Trimmed amp Trimmed CCR Phase 2 testing differed from phase I in that both systems were tested together The test diver entered the pool checkin
46. sure hose to run straight up in the middle of the two counterlung connections Be careful when handling not to stress the epoxy seal 79 Your instructor will show you how to set the intermediate pressure of the oxygen first stage regulator to obtain the proper flow rate Itis recommended to start around the 165 psi range Counterlung Attachment To install the counterlungs wipe down the inside of the counterlung ring on each counterlung and counterlung connection with lint free cloth Lightly lubricate the inside ring on the counterlung with silicone grease and then press the counterlung on to the counterlung connection Make sure to hold the back of the connection to keep from stressing the tubes attached to the scrubber head Next screw the counterlung connection ring to the counterlung Finger tight Secure the bottom of the counterlungs around the center post with Velcro tab This keeps the counterlungs from accidently floating up 80 Counterlung Attached to Counterlung Connection Base of both Counterlungs Secured Scrubber Canister Insert the bottom of the scrubber basket in to the scrubber canister with the center tube facing up Plug the center tube with paper towels to keep the scrubber median from entering the center tube 81 Fill the scrubber canister 1 3 of the way then tap all sides of the canister to pack the scrubber median Repeat this two more times until the scrubber canister is filled Place
47. veloped in the past and present technological advancements in dive gear allow mankind to explore farther and deeper into the underwater world The eventual twentieth century development of basic open circuit scuba equipment marked the start of the now fully evolved closed circuit re breathers Yet an impasse for modern deepwater divers still exists There continues to be an increasing need for more reliable essential devices such as multiple re breathers backup re breathers and or smaller utilitarian rebreather which offers the diver smaller profile while investigating his or her underwater environment This thesis presents new rebreather to address these issues It must be pointed out that the design contained within this document has not been proven outside of the laboratory and should not be used for open water use until a fully tested professionally manufactured system becomes available Patent Pending The author and professors that have signed off on this technology are not liable for miss use of this design 1 1 Purpose of SMM The purpose of the Side Mount Machine Closed Circuit Rebreather SMM CCR shown in Figure 1 is to enhance the safety and reliability in conducting deeper and or longer dives whether the exploration is in the open ocean or maneuvering thousands of feet inside an extensive cave system The SMM provides the diver with an easily attachable mixed gas rebreather that is worn on the side rath
48. x Pro Engineer Renderings 2 2 62 Appendix D Technical Drawin ess 67 Appendix E 2 72 Appendix F User Maintal ausland 73 vi List of Figures Figure 1 SideMount Machine CCR being worn by 2 Figure 2 Profile View of SMM setup vs Traditional Setup 3 Figure 3 Edmund Halley s Diving 7 Figure 4 Lethbridge s Diving SULA 8 Figure 5 Augustus Siebe s Diving Dress 9 Figure 6 US Navy MK 12 amp Vu 10 Fedre Aqua LUNS aat 12 Figure 8 Fleuss Diving Apparatus 13 Figure 9 LARU amp Draeger Lung Automatic Regenerator 14 Figure 10 Basic CCR Schematic sagene ea 20 Figure 11 Dive Surface Valve amp Bailout 21 Figure 12 Over the Shoulder Counterlungs 2 23 Figure 13 Back mounted Counterlungs an naeh 24 Figure 14 Axial and Radial Scrubbers 4 444 000 000 25 Figure 15 Kiss Classic Manual Add 28 Figure 16 Kiss Classic PPO Displays sn ne as 28 Figure 17 Kiss Classic Scrubber grey cylinder amp 29 Figure 18 rEvo DualSer bber 30 Figure 19
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