Types of Random Packing

Large random packing has a higher capacity, but efficiency is low while small packing has high efficiency with lower capacity. You should select the most economical packing that balances efficiency and power.
a) Pall Ring Packing
It is similar to the Raschig ring but with “fingers.” Pall rings are punched on the side to create internal drips which increase the capacity efficiency by 50% to 80% compared to the Raschig Rings. They have the same height as diameter and are commonly used in distillation and absorption services.
b) Raschig Ring Packing
Raschig Ring is the first generation of random packing which was designed with a height equal to the diameter. It is made of metal and it is less common due to its low efficiency, low capacity, and high costs. It's only used in corrosive applications such as ceramic or carbon/graphite construction materials. It lacks internal support known as “fingers.”
c) High-Performance Saddle Ring
It was designed to create a low aspect ratio or height less than the diameter. When installed, it settles in a way that it orients more flat surfaces parallel to liquid and vapor traffic. The surfaces increase capacity while maintaining an effective contact surface area. High-Performance Saddle Rings offer higher efficiency and capacity than the Pall Ring Packing.
They are commonly used in sour water stripping, atmospheric and high-pressure distillation, demethanizers, euthanizes, quench towers, acid gas removal, and main fractionators.
d) SuperBlendTM 2-Pac Packing
It uses two distinct Saddle Ring high-Performance Packing, large and small packing. Large packing is for high capacity, and pressure drop, and small packing is for higher efficiency. The small packing fits in the interstitial voids of the more extensive packing to create a more effective surface area without decreasing the capacity. The combination increases the efficiency of large packing by 25% or the capacity of small packing by 15%.
This packing is commonly used in fine chemical distillation, absorption, and stripping, refinery fractionators, and retrofit opportunities.
e) Lessing Ring
They are designed from the Raschig Ring and are made out of ceramic. They have internal drips which enhance mass transfer and increase the surface area. They have a high density. Thus they have excellent acid and heat resistance. They are used in regenerative oxide and transfer systems because they withstand corrosion.
f) Dixon Rings
Dixon rings are similar to Lessing in design, but they are made of stainless steel mesh. The mesh gives Dixon rings a low-pressure drop. They have a high rate of the mass transfer due to the large surface area. They still keep a high mass transfer rate despite having a high liquid hold-up, large surface area, and low-pressure drop. They are mainly used in scrubbing applications and laboratory distillation.
Where is Random packing used?
 When the tower has a small diameter？

It is impossible to install trays in towers with a diameter of less than 0.9m (3 feet). Packing is the most reliable and efficient choice for small-diameter towers.
• Processes with Low-pressure drop
Used when pressure drop in packing towers is way too lower than in tray towers. Trays have a free area of about 5% to 10% of the tower cross space while that of packing is more than 50%.
• Corrosive systems
Random packing comes in a range of materials such as plastic, ceramic, and metal which are resistant to corrosive fluids.
• Increasing capacity of operation towers
If the tower with trays has low capacity, it can be upgraded with random packing to upgrade the capacity.

Pall Rings

Metal pall ring is an important type of pall ring. Compared with plastic pall ring, the metal pall ring has better corrosion and rust resistance to be used in the extremely harsh environments. Metal pall ring is mainly made of carbon steel, galvanized steel, stainless steel and other materials. Stainless steel pall ring is the most popular and widely used type because of the best corrosion resistance and chemical stability performance.
Similar to the ceramic pall ring, there are two layer of windows on the cylinder wall. And each layer has five ligules, which is punched and bending inward the axe of ring.

 Applications of Metal Pall Rings

1. · Separation and absorption applications at atmospheric pressure.
2. · Where low pressure drop under vacuum is critical.
3. · Stripping applications.
4. · Quenching tower.
5. · Direct contact cooling applications.
6. · Suitable for high temperature applications
7. ·H 2 S, NH 3 and SO 2 absorption and stripping
8. · Stripping
9. ·Reaction tower
10. · Distillation column

Specifications Of Metal Pall Rings

1. Material: carbon steel, stainless steel, Monel, Titanium, aluminum and many other high alloy and duplex specialty metal.
2. Diameter: 16 mm, 25 mm, 38 mm, 50 mm, 76 mm and 90 mm.
3. Thickness: 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm,0.9 mm and 1.0 mm.

 

Specifications of metal pall ring
Item	Size (D × T × H ) (mm)	Bulk density (kg/m3)	Filling quantity	Surface area (m2/m3)	Voidage (%)
SFTPR-01	16 × 0.3 × 16	360	201000	346	95.5
SFTPR-02	25 × 0.4 × 25	302	5100	212	96.2
SFTPR-03	25 × 0.5 × 25	400	54000	216	95
SFTPR-04	25 × 0.6 ×25	461	5400	219	94.2
SFTPR-05	38 × 0.4 × 38	262	15180	145	96.7
SFTPR-06	38 × 0.6 × 38	328	15000	146	95.9
SFTPR-07	50 ×0.5 × 50	194	6500	106	97.5
SFTPR-08	50 × 0.7 × 50	285	6500	108	96.4
SFTPR-09	50 × 0.9 × 50	365	6500	109	95.4
SFTPR-10	76 × 0.8 × 76	205	183	69	97.4
SFTPR-11	90 × 1.0 × 90	229	1160	62	97.1

Performance Consideration

Packing Size mm	16	25	38	50	90
Free Space %	93	94	95	96	97
Specific Surface Area (m2/m3)	316	209	122	100	54
No. Per Unit Volume (m3)	210,000	49,500	13,450	6,000	1,000

Specifications Of Metal Pall Rings Technical Information

Features of Plastic Pall Rings

1. · Large flux.
2. · Low resistance.
3. · High mechanical strength.
4. · High separation efficiency.
5. · High operational flexibility.
6. · High mechanical strength.
7. · Chemical resistance, such as acids, bases, salts.
8. · Temperature stability.
9. · Various interior shapes. Can be adapted to different applications.
10. · Different colors. All colors can be customized.