Large Angle Diffuser (LAD®)

LAD®: 

LAD ® Cheng Fluid Systems, Inc. 480 San Antonio Road, Suite 120 Mountain View, CA 94040 www.chengfluid.com LAD®

LAD® General Information: 

LAD® General Information The Large Angle Diffuser (LAD ® ) is located inside a standard concentric diffuser and protrudes a small distance inside the small diameter piping section. The LAD ® consists of a series of overlapping, truncated cones, all with a common focal point, which is located within the expansion. Cheng Fluid Systems, Inc. 480 San Antonio Road, Suite 120 Mountain View, CA 94040 www.chengfluid.com Concentric expansion Feed pipe LAD ® Flow

Slide 3: 

When to Install a LAD®? The maximum angle of expansion you can have without causing backflow is 15°, which results in a very long piece of equipment . Without a LAD ® there is turbulence and backflow . With a LAD ® there is smooth laminar flow, and a more compact piece of equipment. Benefits: · Diffuser is more compact · Less loss of head · Maximum pressure head recovery LAD ® 15 °

LAD® Effects: 

LAD ® Effects Velocity reduction in the central zone, with a uniform exit profile Fluids will obey trajectories of the point source and will then be distributed uniformly in the expansion as if from a singular point.

LAD® Effects : 

LAD ® Effects No LAD ® With LAD ® Velocity profile at mid plane of expansion Back mixing A LAD ® creates a uniform exit flow profile and eliminates back mixing of the fluids.

Experimental Results showing how LAD® can eliminate flow separation in an expansion.: 

Experimental Results showing how LAD ® can eliminate flow separation in an expansion. Without LAD ® With LAD ®

Process Equipment Improves with LAD® & CRV® Technology: 

Process Equipment Improves with LAD ® & CRV ® Technology For Platinum gauze & Honeycomb monolith Catalytic reactors (top pictures) And Heat Exchangers (bottom) Inlet piping turns and Large Concentric expansions Cause poor fluid distribution Using LAD ® and CRV ® Technology, A More Uniform Flow Distribution Occurs And Component Performance Improves

Elbow and Sudden Expansion Affect Condenser Performance: 

Elbow and Sudden Expansion Affect Condenser Performance Long Radius 60 Inch Diameter Mitered Elbow

Elbow and Sudden Expansion cause Flow Problems at Tube Entrance: 

Elbow and Sudden Expansion cause Flow Problems at Tube Entrance Tube Sheet Areas Not Fed Results Showed only 65% of Tubes are received cooling water.

Elbows and Sudden Expansion Affects Condenser Performance: 

Elbows and Sudden Expansion Affects Condenser Performance Two Closely Coupled Long Radius Elbows Cooling Water Flow Direction Cooling Water Must Make 90 ° Sharp Turn and Suddenly Expand to Flow To Tube Sheet Flow Rates Varies from 2910 to 4747 GPM

Turbulence Caused by Elbows and Reducer Affect Condenser Performance: 

Turbulence Caused by Elbows and Reducer Affect Condenser Performance Fluid Turbulence Caused By Elbows and Reducer Result in Non-Uniform Velocity Profile at Water-Box Nozzle Inlet

Sudden Expansion and Sharp 90° Turn Cause Tube Flow Problems: 

Sudden Expansion and Sharp 90° Turn Cause Tube Flow Problems Non-Uniform Water Box Exit Velocity Profile

Improve Condenser Performance with LAD® and CRV® Technology: 

Improve Condenser Performance with LAD ® and CRV ® Technology New LAD ® Nozzle Design CRV ® Water box CRV ® CRV ® Tube sheets

Improve Condenser Performance with LAD® and CRV® Technology: 

Improve Condenser Performance with LAD ® and CRV ® Technology High Flow Rate Case of 4747 Cubic Meters per Hour 90% Tubes Now Receive Cooling Water Only Small Corner Region Has No Flow

High Pressure Losses Can Occur in Exhaust Region: 

High Pressure Losses Can Occur in Exhaust Region Struts Sudden Large Expansion Concentric Turning Vanes 90º Turn Flow Separations around the Struts, Turning Vanes and in the Large Expansion Area can cause High Pressure Losses of as much as 60 " Water(0.15 kg/cm 2 )

LAD® and CRV® Technology Can Lower Exhaust Pressure Loss: 

LAD ® and CRV ® Technology Can Lower Exhaust Pressure Loss Shaft Channel Cross Section View Interior Turning Vanes Removed Overlapping LAD ® Cones to Control Sudden Expansion Flange Connections to Connect To Existing Ductwork New CRV ® Strut Design to Preserve Rotation of Gas

Specifying a LAD® Flow Conditioner: 

Specifying a LAD ® Flow Conditioner LAD ® Large Angle Diffuser Information Needed to fit application Location where LAD ® needed (Condenser, Sudden Expansion, etc.) Flow Conditions Piping Diameter/Schedule, Piping Material Expansion Geometry Isometric Based on Above Information, CFS will provide a quote for the correct Large Angle Diffuser Design which can be welded into the expansion . CFS can perform CFD simulations to prove design works

LAD®: 

LAD ® Cheng Fluid Systems, Inc. 480 San Antonio Road, Suite 120 Mountain View, CA 94040 www.chengfluid.com LAD®