Problem No. 29: Stripper versus decomposer: What is the difference?
A discussion defining the role of the stripper and decomposer in a urea plant and how they differ.
Category: Equipment
Problem No. 27: How do you clean the scraper in a prilling tower?
The scraper in a prilling tower rotates above the floor of the tower and moves the prills from the bottom of the prilling tower to the conveyor belt. Under certain conditions, the scraper can get clogged and requires cleaning, but how can this be done safely?
Problem No. 23: CO₂ compressor capacity limitation
The CO2 compressor in a urea plant is often a limiting factor in the urea plant. This discussion shares experiences on how best to debottleneck this unique and interesting high-pressure rotating piece of equipment.
Problem No. 21: Vibrations in the discharge line of the HP reciprocating carbamate pump
In all urea plants, high pressure pumps are used to pump the feedstock ammonia and carbon dioxide to the high pressure synthesis section and in most urea plants carbamate liquid is recycled from the recirculation section to the synthesis. Reciprocating pumps are used for these services and sometimes vibration problems occur in the discharge pipeline. This discussion considers the possible causes and solutions to problem.
Problem No. 20: Unblocking pipelines after a urea plant shutdown (continued)
A discussion on what measures can be taken to unblock pipelines and heat exchangers after a urea plant shutdown.
Problem No. 19: High pressure pumps – which is better reciprocating or centrifugal?
In every urea plant, high-pressure pumps are used to pump the feedstock ammonia and carbon dioxide to the high-pressure synthesis section and in most urea plants carbamate liquid is recycled from the recirculation section to the synthesis section. This discussion compares the advantages and disadvantages of reciprocating and centrifugal pumps based on operating experiences in the industry.
Problem No. 17: Loose liner or overlay welding?
A discussion about the differences between loose liners and overlay welding for protection of high pressure equipment in urea plants.
Problem No. 16: High pressure scrubber problem
Sometimes a serious problem occurs in a urea plant, which forces the plant to reduce capacity or even forces a shutdown. It is then vital to find the root cause of the problem as soon as possible, especially if the problem repeats. Such a situation happened at Khorasan Petrochemical Company in Iran which experienced a problem with the high pressure scrubber.
Problem No. 15: Pressure safety valve experiences
Pressure safety valves are critical equipment items in any chemical process plant. This article discusses experiences and challenges of pressure safety valves in urea plants.
Problem No. 13: 3-Way valves in urea melt lines
In several urea plants, 3-way valves in urea melt lines have experienced leakage problems but successful innovations are available that provide a reliable solution.