Heat Transfer with Plate 10152014 Plate Heat Exchangers

Heat Transfer with Plate 10/15/2014

Plate Heat Exchangers - Plate 10/15/2014

What is best heat transfer choice? Shell & Tube: Heavy Duty Plate: Efficient 10/15/2014

What is best choice? Plates: Higher Coeffecient = Lowest Cost Tubes: Higher Pressure & Temperature Limits

Fluids channeled in opposite directions on alternating plates for efficiency. 10/15/2013

How it works q Plates are parallel or same side flow (not diagonal) q Rotating plate 180° puts flow on opposite side and direction

How it works q High turbulence q True counter current flow path q Low fouling from scouring action of flow q Highest heat transfer coefficients

Heat Transfer Coefficients Heat transfer coefficients: Btu / Hr – Ft 2 - F Application S&T Plate Water/Water 400 -500 1400 -1500 q Higher heat transfer coeffecients mean lower surface area and lower cost q Higher coeffecients and lmtd’s result in lower surface area and cost – see next page

Drivers: Coefficient & Temperature Difference Surface Area = U Q x LMTD = $ Q = Heat transfer duty = Btu/hr U = Overall heat transfer coefficient = Btu/hr. sqft. F LMTD = Log mean temperature difference = °F = ( Thot in – Tcold out ) – ( Thot out – Tcold in ) ln ( Thot in – Tcold out ) ( Thot out – Tcold in )

Flow Arrangement – One Pass q All connections on fixed end q Single pass only may be specified.

Flow Arrangement – Multi Pass q Connections on moveable end – must disconnect for servicing

Two corrugation types; H, L H L q 30° Chevron q High Press q 60° Chevron q Low Press Drop q High Heat Transfer Drop q Lower Heat Transfer

Flow Path H–H H–L L-L

PHE Benefits LOWER VOLUME COMPACT DESIGN HIGH HEAT TRANSFER COEFFICIENTS LOWEST INSTALLED COST! LESS MATERIAL

Factors in Choosing a PHE q Design Pressure q Design Temperature q Temperature Crossing q Corrosive Fluids q Particles in Fluids q Fouling / Cleanability

Pressure / Temperature Limits Designed For: q Pressures up to 300 psi (new plate stamping technology now allows for over 400 psi) q Temperatures: -10°F to +320°F

Temperature Crossing and Approach

Temperature Crossing q Temperature crossing not possible in shell & tube not pure counterflow

PHE Benefits CLOSER APPROACH TEMPERATURE CROSSING COUNTER CURRENT FLOW LOWER ENERGY COSTS! GREATER HEAT RECOVERY

Corrosive Fluids q Swimming pools and open groundwater heat pumps can be high in chlorides q 304 SS plates good to 75 ppm Cl q 316 SS plates good to 200 ppm chlorides q Titanium plates good for greater than 200 ppm chlorides

Particles in the Fluids q Open cooling towers and ponds can be high in particles q Standard plates can pass particles that are 75% of the free channel ( 1/16” to 1/8” for standard plates) q Provide an appropriate strainer in the heat exchanger inlet q Flow fluids with particles downward in heat exchangers q Provide back flushing system to periodically clean the unit

In Line Port Strainers q Removable Port Strainer q Removed via moveable rear head

Fouling Factors / Cleanability q Fouling – The build up of an unwanted substance (dirt, minerals, etc) on a heat transfer surface area q Reduces heat transfer capabilities q Fouling Factor – a “fudge factor” that over sizes the heat transfer device in order to overcome fouling. q Fouling factor = Excess heat transfer surface area Excessive fouling factors add dead heat transfer surface to a plate heat exchanger causing lower performance from less velocity across the plate.

Fouling Factors q The term “Fouling Factor” was developed by TEMA (Tubular Exchanger Manufacturing Association) q It is needed as S&T heat exchangers are not symmetrical (shell side Vs tube side) and therefore should not have the same amount of excess surface area added to each side.

Fouling Factors q 1/Uf = 1/Uc + FF q where Uf is the fouled overall heat transfer rate q where Uc is the clean overall heat transfer rate q using typical S&T FFs of 0. 001 ft 2 F/Btu yields; 10% Excess Surface should be specified or FFs in 0. 0001 to 0. 0005 range

Frame Construction

Frame Construction Carrying Bar Tightening Bolts Plates / Plate Pack Rear Support Column Guiding Bar Movable Head Connection Port Fixed Head

Frame Features q ASME Section VIII for safety q Canadian Registration q All bolted construction for reassembly at job site q Zinc plated tightening bolts q Stainless steel plate carrying bars

Standard NPT Threaded Connection Types NPT Threaded ANSI Studded W/ Alloy Nozzle Use ANSI studded when flanged connections are specified for lowest cost ANSI Studded W/ Alloy Liner Optional ANSI Flanged Sanitary Ferrule Quick Disconnect

Frame Features q Many different sizes to be competitive q Sized with 20% room for expansion w/ plates q Connections sizes up to 14” q Up to 400 psi working pressure

Frame Features q Safety shield on every unit q “OSHA Approved” q Protects passerby from leaks q Prolongs gasket life by limiting exposure to elements

PHE Benefits EASY SERVICING MECHANICAL CLEANING POSSIBLE ALL BOLTED CONSTRUCTION LOWER MAINTENANCE COSTS!! REDESIGN CAPABLITY

Optional Construction q Rigid insulation with drip tray q All removeable q For chilled water apps prevents sweating of heat exchanger q Saves energy q Cloth blanket insulation for heating applications

Advantage: Plates are key

The Plate

Plate Depth determines; q Plate thickness q Minimum tightening dimension q Pressure rating q Heat transfer rate q Particle size to pass / fouling risk q Typical plate depths are 0. 1” minimum to 0. 15” standard q Some very wide gaps available

Advantage: Plates q Many different plate sizes: 0. 1” to 0. 15” deep q Use best plate styles that have been used for years – all AHRI approved q All parallel flow; no diagonal q Optimum distribution areas – no stagnant areas q One time plate pressing q Gasket 100% confined

Tightening Dimension Tightening dimension is critical for sealing heat exchangers properly.

Plates q Plate Materials q 304 SS q 316 SS q Titanium q Plate Patterns q H (High theta) q L (Low theta) q Plate Thickness q 0. 4, 0. 5, 0. 6, 0. 7 mm

Plate Design q Units with ports sizes 4” and smaller use a unique interlocking corner alignment system q Guarantees proper alignment and sealing of heat exchanger

Plate Design q Units with ports sizes 6” and larger use a unique 5 point alignment system q Guarantees proper sealing of the heat exchanger while allowing for easy assembly and disassembly “Plate cannot shift in any direction. ”

Double Wall Plate Geometry q Double wall plates protect one fluid from contaminating the other if a plate fails Gasket Double Wall Plate Potable Water Air Gap Fluid leaks to the outside. Boiler Water Plate Failure

Gasket Materials q Nitrile (NBR) q Good for general service q 230°F maximum q EPDM q Superior resistance to higher temperatures i. e. steam q Longer gasket life q 320° F maximum q. Life expectancy of gaskets is 5 years based on temperatures listed above

Gasket Design q Gasket failures always are to the outside of the heat exchanger

Gluefree Gaskets q Gluefree q Glued

Gasket Gaske. Design sealing q. Ridged Gaskets plate Others q Higher sealing pressures q Better sealing of heat exchanger q Longer life and reliability

PHE Certifications q ASME Section VIII q CRN q AHRI Performance Certification q January 2015

Plate Models / Sizes 14” 10” Connection Sizes 4” 8” 6” WP 140 WP 101 WP 45 WP 60 WP 61 2” 1” WP 20 WP 10 WP 21 WP 40 WP 41 WP 80 WP 81

AHRI Performance Certification q AHRI Certification q Standard 400 for Liquid to Liquid Heat Exchangers q Product listed at www. ahridirectory. com q Guarantee of performance by third party

AHRI Performance Certification q As required by ASHRAE 90. 1 and individual engineers q Applications that are exempt; q Glycol applications q Flows over 2, 000 gpm q ASHRAE 90. 1 accepted by some states

Heat Transfer Products The End Thank You 10/15/2014