Good acid distribution systems in any tower are extremely important to ensure optimal working of the Sulphuric Acid plant. An acid distributor is at the heart of the drying and absorption tower system with the purpose of distributing acid evenly over the packing. Complete contact and mixing of gas and acid will ensure proper working of the drying and absorption towers.
Advantages of Alloy Pipe Acid Distributors
- Higher Efficiency
The performance of acid distributors can be compared based on number of acid distribution points and branch pipes per m2. Cast iron distributors limit the number of distribution points. Alloy distributors allow a significant increase in distribution points by 2 to 4 times compared to cast iron distributors.
- Low Corrosion
Cast iron distributors usually have corrosion rates upward of 100mpy (2.5mm/yr). High corrosion causes sulphate formation (sludge deposition) in the tower which leads to plugging of tower packing, poor acid quality, gas channeling, frequent shutdowns and maintenance and lower life of mist eliminators. Alloy distributors have corrosion less than 2mpy (0.05mm/yr) depending on the alloy used, thus there is no sulphate forming problem allowing the distributor and tower operations to be clean.
- Longer Life
Life of alloy distributors is 2 to 3 times longer than cast iron distributors due to low corrosion. Recently, the Galiakotwala team inspected alloy distributors installed 15 years ago in all three towers in a Sulphuric Acid plant. The alloy distributors were observed to be absolutely clean with minimal corrosion.
- Constant Performance
Higher corrosion in cast iron distributors leads to an increase in the size of distribution holes (orifices) causing a reduction in distribution efficiency over time. Due to lower corrosion of alloy distributors, the size of distribution holes do not change maintaining constant performance and efficiency over the lifetime of the alloy distributor.
- Low Maintenance
There is practically zero maintenance for alloy distributors. Once installed alloy distributors only require periodic inspection of the branch pipes and main header to check for plugging.
- No Stocking of Spare Parts
Cast iron distributors are made in blocks and plant operators have to deal with the availability and stocking of spare parts. Entire blocks need to be changed in case of a leakage. This is not the case with alloy distributors which are easily weldable by conventional welding techniques. No stocking of spare parts is required for alloy distributors.
- Easy to Install
Alloy distributors are light in weight, one man can easily lift components of the alloy distributor. This allows for easy installation and handling of alloy distributors.
- Easy to Clean
Each branch pipe can be easily disconnected from the main header for cleaning during a shut down.
- Reduced Load to Mist Eliminators
Alloy distributors are designed to be installed above the packing with gentle distribution over the tower packing. This reduces areas of high velocity gas flow, minimizing mist generation and pressure drop and thereby reducing load to mist eliminators.