Plastic Teller Rosette Size Selection: 25 vs 47 vs 51 vs 59 vs 73 vs 95 vs 145 mm

Plastic Teller Rosette size selection changes much more than nominal diameter. Across DAIER's catalog-confirmed 25–145 mm series, specific surface area generally decreases from approximately 269 to 65 m²/m³, void fraction rises from about 82% to 95%, and dry packing factor falls from approximately 488 to 76 m⁻¹.

The verified product series includes approximately:

• 25 mm;
• 47 mm;
• 51 mm;
• 59 mm;
• 73 mm;
• 95 mm;
• 145 mm.

The core engineering trade-off is:

Smaller Teller Rosette → greater geometric contacting area and a finer packed bed

while:

Larger Teller Rosette → greater free volume, fewer packing elements and generally lower packing factor.

However, this product family contains important supplier-specific geometry differences, so:

nominal diameter alone is not enough to select a Teller Rosette model.

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1. DAIER Plastic Teller Rosette Size Data

DAIER's catalog-aligned engineering database provides the following verified values:

The catalog data also show that Teller Rosette models differ in:

• overall dimensions;
• internal loop arrangement;
• number of rings.

Therefore, this is not simply one geometry scaled proportionally larger.

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2. Why Teller Rosette Size Selection Is Different from a Simple Ring

For a conventional Raschig Ring, engineers often focus heavily on:

• outside diameter;
• height;
• wall thickness.

Teller Rosette is different.

The catalog model also changes:

• internal loop count;
• loop arrangement;
• element height;
• internal spacing.

For example:

25 mm

Uses a 5-ring geometry.

47–51 mm

Use 9-ring geometries.

59–73 mm

Use 12-ring structures.

95 mm

Uses 18 rings.

145 mm

Uses 20 rings.

This means:

a larger Teller Rosette is not simply an enlarged copy of the smaller model.

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3. What Happens to Surface Area as Size Increases?

The broad trend is downward:

• 25 mm — 269 m²/m³;
• 47 mm — 185 m²/m³;
• 51 mm — 180 m²/m³;
• 59 mm — 127 m²/m³;
• 73 mm — 94 m²/m³;
• 95 mm — 98 m²/m³;
• 145 mm — 65 m²/m³. 

But notice the important exception:

95 mm has slightly more specific surface area than 73 mm.

So the relationship is not perfectly monotonic.

The reason is that the internal rosette geometry changes.

Therefore:

Do not calculate Teller Rosette surface area from nominal diameter alone.

Use the actual supplier model.

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4. Why Void Fraction Matters

Void fraction increases strongly across the family:

• 25 mm — 82%;
• 47 mm — 88%;
• 51 mm — 89%;
• 59 mm — 89%;
• 73 mm — 90%;
• 95 mm — 92%;
• 145 mm — 95%. 

Higher void fraction creates more physical volume for:

• gas flow;
• liquid drainage;
• counter-current contacting.

This generally makes larger Teller Rosette models more attractive as:

• gas throughput increases;
• pressure-drop sensitivity increases;
• fouling becomes more important.

But voidage is only one factor.

The tower must still achieve enough mass transfer.

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5. Why Packing Factor Matters

The verified dry packing factor decreases from:

• 25 mm — 488 m⁻¹;
• 47 mm — 271 m⁻¹;
• 51 mm — 255 m⁻¹;
• 59 mm — 213 m⁻¹;
• 73 mm — 180 m⁻¹;
• 95 mm — 129 m⁻¹;
• 145 mm — 76 m⁻¹. 

This is a strong hydraulic trend.

As Teller Rosette size increases:

the packed bed moves toward lower geometric resistance.

However:

packing factor is not the same as actual pressure drop.

Real ΔP still depends on:

• gas velocity;
• liquid flow;
• bed height;
• fluid density;
• viscosity.

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6. 25 mm Plastic Teller Rosette

The 25 mm model is the smallest verified product.

Its catalog data include:

• 269 m²/m³ surface area;
• 82% void fraction;
• 85 kg/m³ bulk density;
• 170,000 pcs/m³;
• 488 m⁻¹ packing factor;
• 5-ring geometry. 

This places it clearly at the:

high-area / fine-bed

end of the product family.

25 mm May Be Attractive When

• strong contacting-area density is required;
• process fluids are relatively clean;
• hydraulic load remains moderate;
• tower diameter favors smaller packing.

Main Limitations

It is less attractive when:

• fouling is significant;
• solids are present;
• gas throughput is very high;
• pressure-drop margin is limited.

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7. Why 25 vs 47 mm Is a Major Bed Change

Moving from 25 to 47 mm changes:

Surface Area

269 → 185 m²/m³

Void Fraction

82% → 88%

Packing Count

170,000 → 32,500 pcs/m³

Packing Factor

488 → 271 m⁻¹.

That is a very substantial shift.

So the 47 mm product is not merely:

“a slightly larger 25 mm Teller Rosette.”

It creates a much more open random bed.

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8. 47 mm Plastic Teller Rosette

The 47 mm model provides:

• 185 m²/m³ surface area;
• 88% void fraction;
• 58 kg/m³ bulk density;
• 32,500 pieces/m³;
• 271 m⁻¹ packing factor;
• 9-ring geometry. 

This gives it a useful intermediate position.

It retains substantial geometric area while greatly increasing bed openness compared with 25 mm.

It may deserve stronger consideration where:

• mass transfer remains important;
• a lower-density bed is desired;
• 25 mm appears unnecessarily fine.

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9. 51 mm Plastic Teller Rosette

The 51 mm model is close in nominal size to 47 mm and uses a similar 9-ring arrangement.

Verified values are:

• 180 m²/m³ surface area;
• 89% void fraction;
• 57 kg/m³ bulk density;
• 25,000 pieces/m³;
• 255 m⁻¹ packing factor. 

Compared with 47 mm:

• surface area falls only slightly;
• void fraction rises slightly;
• packing count decreases;
• packing factor falls.

Therefore, 47 and 51 mm occupy relatively close positions, but they are not identical.

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10. Why 47 and 51 mm Should Not Be Treated as the Same Product

The models have similar:

• height;
• internal 9-ring geometry.

But catalog data differ.

47 mm

185 m²/m³88% void271 m⁻¹ packing factor

51 mm

180 m²/m³89% void255 m⁻¹ packing factor.

For a new project, that difference may be modest.

For an existing tower replacement, however:

exact product dimensions should still be confirmed before substitution.

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11. 59 mm Plastic Teller Rosette

The 59 mm model changes to a 12-ring geometry.

Its verified properties are:

• 127 m²/m³ surface area;
• 89% void fraction;
• 48 kg/m³ bulk density;
• 17,500 pieces/m³;
• 213 m⁻¹ packing factor. 

Compared with 51 mm, the surface-area reduction is much larger:

180 → 127 m²/m³.

This is one reason internal geometry should be examined rather than assuming continuous proportional scaling.

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12. Why 59 mm Is an Important Transition

59 mm maintains the same published void fraction as 51 mm:

89%.

But it has:

• much lower surface area;
• fewer packing elements;
• lower packing factor. 

Therefore, the primary benefit of moving toward 59 mm is not more catalog voidage.

It is:

a coarser bed with lower packing population and packing factor.

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13. 73 mm Plastic Teller Rosette

The 73 mm product provides:

• 94 m²/m³ surface area;
• 90% void fraction;
• 50 kg/m³ bulk density;
• 8,000 pieces/m³;
• 180 m⁻¹ packing factor;
• 12-ring geometry. 

This moves the product family further toward:

• open-bed operation;
• lower element population;
• reduced geometric resistance.

It may deserve stronger consideration when:

• gas throughput rises;
• moderate fouling exists;
• very high geometric area is unnecessary.

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14. 95 mm Plastic Teller Rosette

The 95 mm model is particularly interesting.

It provides:

• 98 m²/m³ surface area;
• 92% void fraction;
• 52 kg/m³ bulk density;
• 3,900 pieces/m³;
• 129 m⁻¹ packing factor;
• 18-ring geometry. 

Notice:

surface area rises from 94 m²/m³ at 73 mm to 98 m²/m³ at 95 mm.

This is a direct consequence of changed product geometry.

So:

larger Teller Rosette does not always mean lower geometric surface area at every adjacent model.

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15. Why 95 mm Is Not Simply “More Open 73 mm”

Moving from 73 to 95 mm changes:

Surface Area

94 → 98 m²/m³

Void Fraction

90% → 92%

Packing Count

8,000 → 3,900 pcs/m³

Packing Factor

180 → 129 m⁻¹.

This is an unusual but useful combination:

more catalog surface area + greater void fraction + lower packing factor.

It demonstrates why different Teller Rosette geometries should be treated as separate engineered models.

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16. 145 mm Plastic Teller Rosette

The 145 mm model is the largest catalog-confirmed size.

Its data include:

• 65 m²/m³ surface area;
• 95% void fraction;
• 46 kg/m³ bulk density;
• 1,100 pieces/m³;
• 76 m⁻¹ packing factor;
• 20-ring geometry. 

This puts it clearly at the:

large/open/low-packing-factor

end of the family.

It may become attractive in large towers where:

• hydraulic openness is strongly prioritized;
• gas flow is high;
• moderate fouling is expected;
• lower geometric area remains acceptable.

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17. Which Size Has the Highest Surface Area?

The verified ranking is:

1. 25 mm — 269 m²/m³
2. 47 mm — 185 m²/m³
3. 51 mm — 180 m²/m³
4. 59 mm — 127 m²/m³
5. 95 mm — 98 m²/m³
6. 73 mm — 94 m²/m³
7. 145 mm — 65 m²/m³. 

The 95-vs-73 mm reversal is important.

It proves that:

specific surface area depends on internal rosette geometry—not nominal diameter alone.

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18. Which Size Has the Highest Void Fraction?

Void fraction generally increases:

82% → 88% → 89% → 89% → 90% → 92% → 95%.

The 145 mm model has the highest verified value:

95%.

That creates a strong preliminary position when high bed openness matters.

But the lower 65 m²/m³ surface area still needs to satisfy the process duty.

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19. Which Size Has the Lowest Packing Factor?

The 145 mm model has the lowest verified packing factor:

76 m⁻¹.

The full progression is:

488 → 271 → 255 → 213 → 180 → 129 → 76 m⁻¹

from 25 through 145 mm.

This strongly supports the general hydraulic trend toward larger sizes.

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20. Bulk Density Is Not Perfectly Monotonic

The verified bulk densities are:

• 25 mm — 85 kg/m³;
• 47 mm — 58 kg/m³;
• 51 mm — 57 kg/m³;
• 59 mm — 48 kg/m³;
• 73 mm — 50 kg/m³;
• 95 mm — 52 kg/m³;
• 145 mm — 46 kg/m³. 

Notice:

• 73 mm is heavier than 59 mm;
• 95 mm is heavier than 73 mm.

Again, the changing internal geometry matters.

Therefore:

do not estimate packed-bed weight by assuming it falls continuously with nominal size.

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21. Size Selection for Clean Contact-Intensive Service

For relatively clean service, preliminary selection may move toward:

25–51 mm

when:

• geometric contacting area matters strongly;
• fouling is low;
• hydraulic load is manageable.

59–95 mm

when:

• contact and hydraulic openness need a stronger balance.

145 mm

when:

• large open passages and low packing factor dominate.

This is preliminary positioning rather than a universal recommendation.

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22. Size Selection for High Gas Throughput

As gas load increases, the engineer generally moves away from the finest 25 mm bed.

Larger Teller Rosette provides:

• greater void fraction;
• fewer pieces;
• lower packing factor.

This can move:

• 73 mm;
• 95 mm;
• 145 mm

higher in the candidate list.

However:

maximum hydraulic openness should not be optimized independently from mass-transfer duty.

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23. Size Selection for Fouling Service

Fouling makes packing population increasingly relevant.

Compare:

25 mm

170,000 pieces/m³.

95 mm

3,900 pieces/m³.

145 mm

1,100 pieces/m³.

Larger packing creates:

• fewer contact points;
• larger characteristic openings.

This may improve practical tolerance for moderate deposits.

But:

Teller Rosette is not universally non-clogging.

Heavy scaling, solids or crystallization can still restrict the bed.

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24. Why Tower Diameter Matters More at 95 and 145 mm

Large random packing requires sufficient cross-sectional population.

A 145 mm element placed in a relatively small tower can create:

• strong wall effects;
• too few elements across the diameter;
• uneven random-bed structure.

Therefore:

145 mm should never be selected solely from its 95% void fraction or 76 m⁻¹ packing factor.

Tower ID must support the geometry.

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25. Very Small Packing Can Also Be Wrong for a Large Tower

Selecting 25 mm simply for its 269 m²/m³ area can create:

• very high packing count;
• much finer flow structure;
• greater fouling sensitivity.

If the process does not need that amount of geometric area, a larger Teller Rosette may provide a more robust operating balance.

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26. Teller Rosette for Scrubber Towers

Plastic Teller Rosette is often relevant to compatible gas-scrubbing duties.

Its open rosette geometry can support:

• gas passage;
• liquid contacting;
• local liquid breakup.

Smaller models may move higher for clean contact-intensive duty.

Larger models may move higher for:

• higher gas flow;
• moderate fouling;
• lower hydraulic resistance.

Actual material compatibility still needs to be confirmed separately.

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27. Teller Rosette for Odor-Control and Air-Treatment Towers

Large plastic Rosette packing may be considered in compatible:

• odor-control towers;
• exhaust scrubbers;
• air-treatment systems.

Such towers often need to balance:

• contact;
• hydraulic capacity;
• fouling tolerance.

The larger:

• 73;
• 95;
• 145 mm

classes can become particularly relevant where very fine packing is unnecessary.

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28. Material Selection Is Separate from Rosette Size

This article addresses:

Teller Rosette geometry and size.

It does not automatically determine the polymer.

DAIER's Engineering Assistant also contains PP Teller Rosette selection nodes for some sizes, but internal material-screening data should not replace actual polymer compatibility review.

Final material selection should consider:

• exact chemistry;
• concentration;
• operating temperature;
• solvents;
• oxidizers.

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29. Replacement Projects Need More Than Nominal Diameter

For an existing Teller Rosette bed, identify:

• nominal size;
• exact dimensions;
• ring count;
• polymer;
• bed height;
• tower ID.

For example:

47 mm and 51 mm both use 9-ring geometries but have different physical properties.

Likewise:

73 mm uses 12 rings while 95 mm uses 18 rings.

Therefore:

same product family does not mean any nearby nominal size is a direct substitute.

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30. Changing Size Is an Engineering Retrofit

Changing:

25 mm → 95 mm

changes:

• surface area: 269 → 98 m²/m³;
• void fraction: 82% → 92%;
• packing factor: 488 → 129 m⁻¹;
• packing population: 170,000 → 3,900 pcs/m³. 

That is a major change in packed-bed behavior.

Therefore:

do not assume the same bed height or process performance after a major Teller Rosette size change.

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31. Support Grid Compatibility

The support grid must retain the selected packing.

Changing from:

145 mm → 25 mm

can make existing support openings unsuitable for the much smaller product.

The support must also provide:

• sufficient open area;
• adequate mechanical strength.

Packing size changes should therefore include an internals review.

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Plastic Teller Rosette Size Decision Table

*95 mm has slightly higher verified surface area than 73 mm because its internal geometry changes from a 12-ring to an 18-ring configuration.

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32. Quick Size Selection Logic

Move toward 25 mm when:

• high geometric area is a strong priority;
• service is clean;
• hydraulic load is manageable.

Move toward 47–51 mm when:

• substantial contact area remains important;
• more open hydraulics are required.

Move toward 59–73 mm when:

• gas capacity and contact need a stronger balance.

Move toward 95 mm when:

• high openness is important;
• a large model is suitable;
• its 18-ring geometry provides useful contacting area.

Move toward 145 mm when:

• the tower is large;
• hydraulic openness strongly dominates;
• lower geometric surface area remains acceptable.

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33. What Information Should Be Included in an RFQ?

Provide:

• Plastic Teller Rosette;
• required size/model if known;
• polymer material;
• tower internal diameter;
• packed height;
• gas composition;
• liquid composition;
• gas flow;
• liquid flow;
• operating temperature;
• operating pressure;
• required removal duty;
• allowable pressure drop;
• fouling or solids information.

For replacement projects also provide:

• exact existing dimensions;
• internal ring count if identifiable;
• photos;
• support-grid opening;
• reason for replacement.

Ask the supplier to confirm:

• full element dimensions;
• ring configuration;
• surface area;
• void fraction;
• bulk density;
• pieces per cubic meter;
• dry packing factor.

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Common Selection Mistakes

Selecting 25 mm Only Because It Has 269 m²/m³ Surface Area

It also has the lowest void fraction and highest packing factor in the verified series.

Assuming Surface Area Always Decreases with Size

95 mm is listed at 98 m²/m³, slightly above 73 mm at 94 m²/m³.

Treating 47 and 51 mm as Exactly the Same

Their catalog properties differ.

Assuming Larger Packing Is Always Lighter

59 mm is lighter than 73 and 95 mm in the verified bulk-density data.

Ignoring Ring Count

Different models use 5-, 9-, 12-, 18- and 20-ring geometries.

Choosing 145 mm Only Because It Has 95% Void Fraction

Tower diameter and required contacting duty must still be checked.

Changing Size Without Reviewing Packed Height

Mass-transfer and hydraulic behavior both change.

Ignoring the Packing Support

Smaller replacement packing may not be retained by the existing grid.

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Frequently Asked Questions

What Plastic Teller Rosette sizes does DAIER's verified database contain?

The catalog-aligned series includes approximately 25, 47, 51, 59, 73, 95 and 145 mm models.

Which size has the highest surface area?

The 25 mm model at approximately 269 m²/m³.

Which size has the highest void fraction?

The 145 mm model at approximately 95%.

Which size has the lowest packing factor?

The 145 mm model at approximately 76 m⁻¹.

What is the surface area of 47 mm Teller Rosette?

Approximately 185 m²/m³.

What is the surface area of 59 mm?

Approximately 127 m²/m³.

Why does 95 mm have more surface area than 73 mm?

Because the catalog geometry changes: the 95 mm product uses an 18-ring structure while the 73 mm model uses a 12-ring structure.

Are 47 and 51 mm interchangeable?

Do not assume so. They are close in geometry but have different surface area, void fraction, packing count and packing factor.

Which size is better for fouling service?

Larger models generally deserve stronger preliminary consideration because they create fewer packing elements and a more open bed, but severe fouling may require another packing family.

Is Teller Rosette size selected only by nominal diameter?

No. Internal ring configuration and exact supplier geometry are also important.

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Selection Takeaway

Plastic Teller Rosette size selection cannot be reduced to “small = more area, large = more open.” The internal rosette geometry itself changes as the model becomes larger.

Across DAIER's verified series:

25 mm → 269 m²/m³ / 82% void / 170,000 pcs/m³ / 488 m⁻¹ packing factor

while:

145 mm → 65 m²/m³ / 95% void / 1,100 pcs/m³ / 76 m⁻¹ packing factor.

But there are important non-linear details:

• 95 mm has slightly higher surface area than 73 mm;
• 59 mm is lighter than the 73 and 95 mm models;
• ring count changes from 5 to 20 across the series.

The correct selection sequence is:

Process Duty → Gas/Liquid Loads → Required Contacting → Hydraulic Margin → Fouling → Tower Diameter → Exact Rosette Geometry → Polymer Compatibility → Support Review

The key principle is:

Select Plastic Teller Rosette from the actual supplier-specific geometry and process duty—not nominal diameter alone.