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Quotes - Engineering - SalesFree-Flow Plate Heat Exchangers
Wide Channel Plates for Difficult Streams
The Free-Flow plate uses a corrugation designed with a far more open fluid path. It gives up some thermal efficiency per square foot and gains the ability to pass material that would bridge across a conventional plate and block the channel.
What it handles. Viscous products, slurries, effluent streams, pulps, and anything carrying fibers or particles up to roughly 3/8 inch. Fruit purees with pulp, mash, stillage, waste streams and paper mill liquors are the typical candidates.
Contamination still controlled. Each medium remains individually gasketed with the interspace vented to atmosphere, so the Free-Flow keeps the same no-cross-contamination behaviour as the standard unit. That matters on food duty where the fluid being handled is exactly the kind that fouls.
Cleaning. The unit is expandable and lightweight, and it disassembles and cleans quickly. On streams that foul heavily, the value of a pack that opens in an hour rather than an afternoon compounds over a season.
Part numbers. Every catalogued model, with the dimensions and ratings that separate them: Accu-Therm Free-Flow Part Numbers (16 part numbers).
Common to the Whole Series
Configuration
- Channel Gap: Wide gap, constant channel width (dimension not published)
- Connection Type: Studded port; sanitary S-line or Q-line ferrule
- Passes: Single pass standard
- Plate Pattern: Free-Flow (FF) - no contact points
- Plate Thickness: 0.6 mm (est.)
- Wall Construction: Single wall gasketed, free-flow
Materials
- Frame: Painted carbon steel; stainless optional. Zinc-plated compression bolts
- Gasket: NBR or EPDM standard; High-Temp EPDM, Viton/FKM, Butyl. FDA/3-A
- Gasket Attachment: Glue-In
- Plate: 316L SS standard; 304 SS, titanium, coated plates optional
Ratings
- Max Temperature: 302°F - 329°F, gasket dependent
- Min Temperature: 32°F MDMT
- Test Pressure: 1.3 x MAWP
Typical Specification
- Plate design: Open flow channel corrugation
- Particle size: Up to approximately 3/8 inch
- Typical fluids: Slurries, pulps, fibrous and viscous streams, effluent
- Gasketing: Each medium individually gasketed, interspace vented
- Materials: 304 and 316 stainless; higher alloys available
- Thermal efficiency: Lower per square foot than standard plates
- Pressure drop: Lower for a given flow than standard plates
- Cleaning: Rapid disassembly; expandable pack
- Duty: Waste heat recovery, product cooling, effluent interchange
- Alternative: Temp-Plate bank assembly for the heaviest solids
| PRODUCT | CONSTRUCTION | MATERIALS | SUPPLY |
| Free-Flow Plate Heat Exchangers | Mueller factory built | 304 / 316 stainless | Authorized representative |
Free-Flow Plate Heat Exchangers
The Trade You Are Making
A Free-Flow pack needs more surface area than a standard pack for the same duty, because opening the channel reduces turbulence. That is the price of not blocking, and on a stream that genuinely carries solids it is a price worth paying every time.
Where the solids loading is heavier still, or the stream is truly abrasive, a Temp-Plate bank assembly with removable plates is usually the better answer and we will say so.
Effluent and Energy Recovery
The most rewarding Free-Flow application is often recovering heat from a waste stream you were previously throwing away, precisely because that stream is dirty enough that nobody wanted to put an exchanger in it.
Interchanging warm effluent against incoming cold make-up water is frequently the shortest-payback heat recovery project in a food or paper plant.
Accu-Therm Free-Flow Part Numbers
Plate & Frame Part Numbers
A free-flow plate has no contact points across the channel. The herringbone pattern that gives a standard plate its turbulence is also what bridges when a stream carries fibre, and a free-flow plate trades some of that turbulence for a channel that passes solids.
What it is for. Stillage, mash, pulp, fruit purees, wastewater with suspended solids, anything where a standard pack would block rather than foul. If your stream is clean, this is the wrong plate — the standard pattern transfers more heat in less area.
The AT161FF is carried as a legacy designation: it appears in the Accu-Therm I&O manual and on installed nameplates but not in current literature.
Accu-Therm Free-Flow Part Numbers
Sizing for the Solids, Not the Clean Case
The gap has to pass the largest particle in the stream with margin, and that is a specification input rather than something we can infer. Tell us what is in the stream and roughly how much of it.
Fouling behaviour follows from that. A free-flow unit still fouls; the difference is that it fouls in a way you can clean, because the pack opens and the channel is reachable.
Expect a Bigger Unit
Lower turbulence means a lower transfer coefficient, which means more surface for the same duty. A free-flow selection is physically larger than the standard-plate selection it replaces, and it should be — a smaller unit that blocks in a fortnight is not the cheaper answer.
Part Numbers
| Part Number | Frame | Plate H | Plate W | Port | Surface Area | Max Flow | Also Written |
|---|---|---|---|---|---|---|---|
| AT40FF | B or F frame | 70-1/4" | 27" | 4" | 99 - 2,292 sq ft | 800 | AT 40FF, AT-40FF, AT40 FF, AT40-FF |
| AT40FFB-10 | B-10 | B Frame, B-10 series | 70-1/4" | 27" | 4" | 99 - 2,292 sq ft | 800 | AT 40FFB-10, AT-40FFB-10 |
| AT40FFB-20 | B-20 | B Frame, B-20 series | 70-1/4" | 27" | 4" | 99 - 2,292 sq ft | 800 | AT 40FFB-20, AT-40FFB-20 |
| AT40FFF-20 | F-20 | F Frame, F-20 series | 70-1/4" | 27" | 4" | 99 - 2,292 sq ft | 800 | AT 40FFF-20, AT-40FFF-20 |
| AT161FF | B or F frame | 70-3/4" | 29" | 3" / 4" | 57 - 1,579 sq ft | 650 | AT 161FF, AT-161FF, AT161 FF, AT161-FF |
| AT161FFB-10 | B-10 | B Frame, B-10 series | 70-3/4" | 29" | 3" / 4" | 57 - 1,579 sq ft | 650 | AT 161FFB-10, AT-161FFB-10 |
| AT161FFB-20 | B-20 | B Frame, B-20 series | 70-3/4" | 29" | 3" / 4" | 57 - 1,579 sq ft | 650 | AT 161FFB-20, AT-161FFB-20 |
| AT161FFF-20 | F-20 | F Frame, F-20 series | 70-3/4" | 29" | 3" / 4" | 57 - 1,579 sq ft | 650 | AT 161FFF-20, AT-161FFF-20 |
| AT184FF | B or F frame | 91" | 36" | 8" | 165 - 2,734 sq ft | 3000 | AT 184FF, AT-184FF, AT184 FF, AT184-FF |
| AT184FFB-10 | B-10 | B Frame, B-10 series | 91" | 36" | 8" | 165 - 2,734 sq ft | 3000 | AT 184FFB-10, AT-184FFB-10 |
| AT184FFB-20 | B-20 | B Frame, B-20 series | 91" | 36" | 8" | 165 - 2,734 sq ft | 3000 | AT 184FFB-20, AT-184FFB-20 |
| AT184FFF-20 | F-20 | F Frame, F-20 series | 91" | 36" | 8" | 165 - 2,734 sq ft | 3000 | AT 184FFF-20, AT-184FFF-20 |
| AT192FF | B or F frame | 111-3/4" | 51-5/16" | 12" | 250 - 5,400 sq ft | 7100 | AT 192FF, AT-192FF, AT192 FF, AT192-FF |
| AT192FFB-10 | B-10 | B Frame, B-10 series | 111-3/4" | 51-5/16" | 12" | 250 - 5,400 sq ft | 7100 | AT 192FFB-10, AT-192FFB-10 |
| AT192FFB-20 | B-20 | B Frame, B-20 series | 111-3/4" | 51-5/16" | 12" | 250 - 5,400 sq ft | 7100 | AT 192FFB-20, AT-192FFB-20 |
| AT192FFF-20 | F-20 | F Frame, F-20 series | 111-3/4" | 51-5/16" | 12" | 250 - 5,400 sq ft | 7100 | AT 192FFF-20, AT-192FFF-20 |
16 part numbers. Figures marked (est.) are engineering estimates rather than Mueller published values — ask us to confirm before designing to one. Everything else traces to the source named in the catalogue record.
Common FAQs
Up to roughly 3/8 inch, depending on the plate selected. Beyond that, or where the stream is abrasive as well as solid-bearing, a Temp-Plate bank assembly with removable plates is the more practical arrangement.
It needs more surface area than a standard plate pack for the same thermal duty, so the unit is larger. Against that, it does not block, which on a solids-bearing stream is the difference between an exchanger that runs and one that does not.
Sometimes, depending on the frame and plate family. Send us the unit nameplate and we will tell you whether a Free-Flow pack can be fitted or whether a new frame is required.
Yes. Each medium is individually gasketed with the interspace vented to atmosphere, exactly as on the standard sanitary unit, so cross contamination is controlled the same way. It is widely used on pulp-bearing juice, purees and mash.
That depends on the channel gap, which varies with the plate. Send us the largest particle size and the solids loading and we will select against it.
Same idea, different vendors' words for it. The plate has an unobstructed channel rather than the contact points a standard herringbone plate uses.
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