Exhaust System Design and Testing Web Copy

The following slides were presented by Bert Browning, Mgr. PD&E, Centek Industries at IBEX 2010 during his ABYC Seminar entitled Exhaust System Design and Testing . We hope you enjoy the presentation and will not hesitate to contact us if you have any questions or if we may be of assistance on your next project.

Exhaust systemsAll exhaust systems are designed and installed on internal combustion engines for one primary purpose; to conduct the products of the combustion process from the engine to a point at the extremity of the vessel without harm to the engine, vessel or personnel. -John R. Ford (Godfather of wet marine exhaust)

3

Topics for DiscussionDesign Considerations Design Advancements Design/System Selection Installation Standards, Rules and Guidelines Case Studies System Testing Results/Conclusion

4

Design ConsiderationsMaterial OptionsMetalUsed for both dry and wet exhaust Hi strength and temperature tolerances Heavy Corrosive and nonnoncorrosive options Costly

PlasticWet exhaust only Low strength and temperature tolerance Light weight Non-corrosive NonCost effective

5

Design Considerations (cont.)Material OptionsCompositeWet exhaust only Fiber-Reinforced Polymer (Fiberglass) FiberCarbon-Fiber Reinforced Polymer CarbonWide range of design strength and temperature tolerances Light weight Non-corrosive NonCost effective6

Design Considerations (cont.)Exhaust System ConsiderationsDry exhaustMust be metal

Wet exhaustCan be either metal, composite or plastic Use highest temperature rated products available

7

Design Considerations (cont.)The importance of temperature ratings

8

Design Considerations (cont.)Vessel and Sound Directives and InitiativesCE Recreational Craft Directive (RCD)PassPass-by test @ 75ft(25m): single engine - 75dB(A) or twin engine - up to 78dB(A)

Standards and SafetyABYC, ABS, Lloyd s UL 94V, Test for Flammability of Plastic Materials Carbon Monoxide (ABYC, Standards and Technical Information Reports for Small Craft, TH-22 and TH-23) THTH-

9

Design Advancements, MetalPastCustom designs difficult, required test fits Mild steel, cast iron, low grade stainless Diffuser/spray head best guess Insulation blankets Connection with pipe flanges; heavy, critical bolt locations on replacement components

10

Design Advancements, Metal (cont.)PresentCustom design seamless with CAD and modeling 316L standard, option of 25-6MO (high nickel 25content) Diffuser/spray head calculated Insulation hardcoat Connection with marmon flanges; lighter, no hole orientation issues, assembled with v-bland clamps v-

12

Design Advancements, CompositePastResins100% petroleum based high styrene content

PresentResinsNonNon-petroleum based Renewable resources Low styrene content Higher corrosion resistance Higher temperature ratings

E-Glass

ECR-Glass, ECRCarbon/Graphite, Aramid (Kevlar) Laminate structure14

Design/System SelectionCONSULT WITH THE EXPERTS OF EXHAUST SYSTEMSRegistered engineering firm

3D ModelingEase of communication between builder and exhaust supplier More feasible custom design AutoCAD, SolidWorks, Pro/E, Rhino, Unigraphics Make certain of compatibility with vendor The right fit, the first timeAlmost anything is possible15

Design/System Selection (cont.)

16

Design/System Selection (cont.)Engine location relative to waterline Hull TypePlaningEngine location above waterlineInline muffler exhaust Waterlift muffler exhaust Waterlift muffler and gas/water separator Muffler/gas/water separation combination unit Underwater exhaust (widely used in semi-displacement hulls) semi-

DisplacementEngine location below waterlineWaterlift muffler exhaust Waterlift muffler and gas/water separator17

Design/System Selection (cont.)System SizingNecessary for engine efficiency and vessel design parametersCleaner operation (fewer combustion byproducts) Achieve rated power and rpm Maximum fuel economy

Not all engines are the same Proper sizing based on engine operating parametersExhaust gas flow Allowed backpressure Raw cooling water flow18

Design/System Selection (cont.)Available space & desired exhaust noise attenuationMaximum muffler volume = maximum possible exhaust noise attenuation

19

Installation Standards, Rules and GuidelinesPrevent water intrusion back to the engine (ABYC P-1: P1.5.11 & 1.5.13) Isolate and Support exhaust components (ABYC P-1: P1.5.8)Minimize transmission of engine/mechanical noise to superstructure Minimize risk of failure from vibration, shock, expansion and contraction NEVER rigidly fix composite exhaust components at more than one point

Provision to drain components (ABYC P-1: 1.5.14) PMinimize damage from freezing water or chemical action when out of service Use gravity to your advantage

20

Installation Standards, Rules and Guidelines (cont.)Surface temperature < 200F (ABYC P-1: 1.5.10) PSeparate exhaust terminus for each engine and generator (ABYC P-1: 1.5.7) PGas tight to hull exterior (ABYC P-1: 1.5.1 & 1.5.4) PDouble clamp all hose connections (ABYC P-1: P1.7.1.10.1) Muffler volume large enough to retain engine cooling water and prevent backing up into the engine (ABYC PP1: 1.7.2.4)

21

Installation Standards, Rules and Guidelines (cont.)Sailboats, waterlift installed as near to centerline as possible and as direct as possible to high point near to centerline (ABYC P-1: 1.7.2.2) PSeacock must be installed on dewatered system with drain below waterline (ABYC P-1: 1.7.2.4) PCarbon Monoxide, exhaust terminus should be located eitherHull side near hull side and transom intersection Transom as far outboard of centerline as practicable Bottom of the boat, OR Above highest occupied deck and its weather enclosure/cover

(ABYC P-1: 1.5.2, TH-22 & TH-23) PTHTH22

Case StudiesCASE STUDY #1Application:65ft Workboat with twin DDA Series 60 600hp

Requirements/Constraints:Engine below waterline Dry exhaust Quiet but no sound directives applied

Solution:Could use either wet or dry exhaust Customer requests dry exhaust 6.63 exhaust23

Case Studies (cont.)Case Study #1

Courtesy of ABYC P-1 FIGURE 4

24

Case Studies (cont.)CASE STUDY #2Application:86ft Sportfish with twin MTU 16V2000M93 2400hp

Requirements/Constraints:Engine above waterline Available space is minimal Quiet but no sound directives apply

Solution:Could use either inline, waterlift or muffler/gas/water separation combination unit Due to space constraints, inline muffler Simple path to terminus 18 exhaust

25

Case Studies (cont.)Case Study # 2Double Clamps Inline Muffler Surge Chamber Insulated Surfaces

Above WL terminus

26

Case Studies (cont.)CASE STUDY #3Application:43ft Cruiser/Sportfish with twin Cummins QSM11 670hp

Requirements/Constraints:Engine above waterline Adequate space available to house large muffler inside engine compartment Quietest possible solution and need to pass exhaust noise initiatives (less than 75dB(A) on 75ft pass by)

Solution:Could use either inline, waterlift or muffler/gas/water separation combination unit Customized dual chambered waterlift muffler 8 In-10 Out exhaust In-

27

Case Studies (cont.)Case Study # 3Dual Chambered Waterlift Muffler (above WL option)

Above WL terminus28

Case Studies (cont.)CASE STUDY #4Application:54ft Trawler with single Cummins QSM11 670hp

Requirements/Constraints:Engine below waterline Sufficient space inside engine compartment Quiet but no sound directives apply

Solution:Must utilize waterlift muffler Simple path to terminus 8 exhaust29

Case Studies (cont.)Case Study # 4High point Loop Waterlift Muffler, low point Anti-Siphon Valve

Above WL terminus

30

Case Studies (cont.)CASE STUDY #5Application:70ft Sailing Yacht with single Yanmar 4JH3-DTE 125hp 4JH3-

Requirements/Constraints:Engine below waterline; sailboat guidelines apply Sufficient space inside engine compartment Quiet but no sound directives apply Long exhaust run

Solution:Must utilize waterlift muffler Simple path to terminus, but long run 4 exhaust

31

Case Studies (cont.)Case Study # 5High point Loop near longitudinal centerline Waterlift Muffler near longitudinal centerline, low point Anti-Siphon Valve

Above WL terminus

32

Case Studies (cont.)CASE STUDY #6Application:54ft Trawler with Northern Lights M864K 25kW

Requirements/Constraints:Generator partially below waterline Sufficient space inside engine compartment Quietest option for generator night operation but no sound directives apply

Solution:Must utilize waterlift muffler, addition of water/gas separation unit Simple path to terminus 2.5 exhaust

33

Case Studies (cont.)Case Study # 6Gas/Water Separator, high point Waterlift Muffler

Above WL dewatered gas terminus

Below WL raw water terminus

34

Case Studies (cont.)CASE STUDY #7Application:100ft Houseboat with Westerbeke 20kW (Gasoline)

Requirements/Constraints:Generator above waterline Sufficient space inside engine compartment Quietest option for generator operation but no sound directives apply

Solution:Design for CO safety Customized muffler/gas/water separation combination unit, 2 In/Out-1.5 Drain exhaust with stack dewatered gas In/Outdischarge Simple path to terminus

35

Case Studies (cont.)Case Study # 7

Courtesy of ABYC P-1 FIGURE 6B

36

Case Studies (cont.)CASE STUDY #8Application:135ft M/Y with twin CAT C32 1100hp

Requirements/Constraints:Engine above waterline Request Underwater exhaust discharge Adequate space available to house large muffler inside engine compartment Quietest and cleanest possible solution

Solution:Could use either inline, waterlift or muffler/gas/water separation combination unit 12 In/Out 6 Bypass/Relief with additional resonator on relief

37

Case Studies (cont.)Case Study # 8Resonator, relief Underwater muffler, (vertical option)

Above WL relief terminus Below WL exhaust terminus with deflector

38

TestingDynamometer (Pre-build) (PreFacilitated by builder in conjunction with engine supplier and exhaust supplier Allows developmental testing prior to build/sea-trial build/seaDuplicate planned system layout Test various muffler designs Obtain actual exhaust noise data Obtain backpressure results and resolve any concerns

Total system backpressureLimits set by engine manufacturer Measure at designated port on turbo flange or 1 after turbo flange Culmination of ALL components and piping in the exhaust system from the turbo/manifold to the terminus

39

Testing (cont.)Typical causes of elevated system backpressureImproperly sized system Too many sharp bends Improper terminus positionHull side terminus where wave pattern blocks terminus Hull bottom with no relief line/port

Determining problematic components/sections to system backpressureUtilize multiple backpressure test pointsRecord pressure drop between components/bends in the system

Correcting system backpressure issuesCONSULT WITH THE EXPERTS OF EXHAUST SYSTEMS40

ReferencesABYC, Standards and Technical Information Reports for Small Craft, Section P-1, www.abycinc.org Craft, PCentek Industries, Inc., www.centekindustries.com DeAngelo Marine Exhaust, www.deangelomarine.com Manuflex Limited, www.manuflex.co.uk Metcalf Marine Exhaust, www.mmxhaust.com Owens Corning, www.owenscorning.com Ashland, www.ashland.com

42

Contact Information

Bert Browning, Mgr. PD&E, Centek Industries, Inc [email protected] (229) 228-7653

43