Ammonia desulfurization -- Equipment material requirements
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The company is using the ammonia-based flue gas desulfurization method. Below is the list of equipment designed by the bidding party; please let me know if there are any issues, and thank you. :Table 7.1: List of Main Process Equipment and Materials for the Handshake SystemSerial Number | Name | Specifications/Model | Material | Quantity | Remarks
--- | --- | --- | --- | --- | ---
I. Main Custom-Made Processing Equipment | 1 | Humidification and Concentration Tower | FRP | 3 units | Includes ladder platforms and internal components |
| | 2 | Venturi Pre-Desulfurization Unit | FRP | 3 units | |
| | 3 | Desulfurization Tower | FRP | 3 units | |
| | 4 | Ammonia Water Tank | FRP | 1 unit | |
| | 5 | Slurry Tank | FRP | 1 unit | |
| | 6 | Mother Liquor Tank | FRP | 1 unit | |
| | 7 | Oxidation Tank | FRP | 1 set | |
| | 8 | Thickerizer | FRP | 1 unit | |
| | 9 | Ventilation Pipes and Supports | Q235B | 1 batch | With special anti-corrosion treatment |
| | 10 | Expansion Joints | 7 sets | |
II. Electric Equipment | 11 | Ammonia Water Pumps | 6 units | Three in operation, three as backups |
| | 12 | Slurry Pumps | 6 units | Three in operation, three as backups |
| | 13 | Circulation Pumps | 9 units | Six in operation, three as backups |
| | 14 | Mother Liquor Pumps | 2 units | One in operation, one as backup |
| | 15 | Oxidation Pumps | 2 units | One in operation, one as backup |
| | 16 | Roots Blowers | 3 units | Two in operation, one as backup |
| | 17 | Automatic Centrifuges | 316L | 2 units | One in operation, one as backup |
| | 18 | Dryers | 316L | 1 set | |
| | 19 | Automatic Packaging Machines | 1 unit | |
| | 20 | Electric Gate Valves | Q235B | 10 units | |
| | 21 | Stirrers | 316L | 3 units | |
III. Electrical System | 22 | Low-Voltage Power Cabinet | 1 unit | |
| | 23 | Electrical Distribution Cabinets | 2 units | |
| | 24 | Voltage-Reduction Starting Cabinet | To be determined | |
| | 25 | Local Control Boxes | 6 units | |
| | 26 | Cables and Cable Trays | 1 batch | |
| | 27 | PLC Control Cabinet | 1 set | Communicates with the boiler’s DCS system |
| | 28 | Plant Lighting | 1 set | |
IV. Instruments, Meters, and Pipeline Valves | 29 | pH Controllers | 3 sets | |
| | 30 | Density Meters | 3 units | |
| | 31 | Level Transmitters | 10 units | |
| | 32 | Differential Pressure Transmitters | 3 units | |
| | 33 | Electric Control Valves | 316L | 10 units | |
| | 34 | Thermal Resistors | 3 sets | |
| | 35 | Electromagnetic Flow Meters | 12 units | |
| | 36 | Laboratory Instruments | 1 batch | Utilizes facilities available at the plant |
| | 37 | Pipeline Materials: ABS or 316L | 1 batch | |
| | 38 | Valves: ABS or 316L | 1 batch | |
| | 39 | Various Pressure Gauges | 1 batch | |
While diving, I noticed that there were many discussions and questions regarding 316L material, so I’m posting this to seek some help.
Original poster: Hello! I think this material is suitable! I have also worked on desulfurization projects, and they chose materials in the same way! 316L has the best corrosion resistance among all stainless steels; it can be used. Original poster: I’m very grateful for your work on electric control valves. If possible, we could work together once!! :lol :lol :lol Just joking, don’t take it seriously~~~~ I specialize in control valves; if you encounter any technical issues with valves, we can exchange ideas and suggestions, and learn from each other to make progress together~~~ We specialize in control valves! This post was last edited by chaochao on 2008-5-24 at 14:39
Hehe. The most important material isn’t specified. FRP should be fine. 316L definitely won’t work; currently, the chloride ion concentration in ammonia-based desulfurization systems is usually above 40,000 PPM. Apart from the drying system, 316 is not suitable for use in other areas. The key is the selection of materials for all the operating equipment that comes into contact with the slurry. Such as the impeller of a pump. Lined rubber definitely won’t work; it has to be alloy.
Upstairs, where does the claim that \"the chloride ion level in the ammonia-based desulfurization system is usually above 40,000 PPM\" come from? If I have a pre-washing step before the ammonia-based desulfurization process, which is simply a second stage of dust removal and temperature reduction, then the chloride ion concentration in the ammonia-based desulfurization system will not be so high. “Such as the impeller of a pump. “Lining with rubber definitely won’t work.” Why is the person upstairs so certain? Have they used it in actual projects? Is the rubber lining not durable enough or not resistant enough to corrosion?
First, the concept of chloride ions in the system is explained; this concentration has no relation to the chloride ion concentration in the flue gas. Those involved in desulfurization know that since the slurry circulates within the system, chloride ions continue to accumulate. The limestone method maintains the chloride ion concentration in the system by discharging wastewater, but the ammonia method does not allow for wastewater discharge; as a result, its chloride ion concentration is generally higher than that designed for the limestone method. As for the impellers of slurry pumps, rubber lining cannot be used; corrosion is not an issue – the main problem is wear, and this is a lesson that has been learned through extensive practical experience in engineering.
In ammonia-based desulfurization systems, the chloride ion concentration is usually above 40,000 PPM – this claim has no basis; I have seen the test reports of one facility, and the actual values are not that high
The ammonia method does not produce wastewater, but it generates the by-product ammonium sulfate, as well as some ammonium chloride.
“As for the impellers of slurry pumps, rubber lining cannot be used; corrosion is not an issue – the main problem is wear, and this is a lesson that has been learned through extensive practical experience. Ammonia-based desulfurization differs from the limestone-gypsum method; so what substances can cause wear on the impellers?
Ammonium sulfide is crystallized and then removed from the system through a series of processes, whereas almost no ammonium chloride crystallization occurs (this has been confirmed through theoretical analysis and practical testing, so there is no doubt about it). If no wastewater is discharged, there is no need for other methods to remove ammonium chloride. So, there is only one way for chloride ions to be removed from the system: through the ammonium sulfate that goes into the dryer, which contains approximately 3–5% moisture. The guy ahead said he had seen the test report, and the value wasn’t that high. I don’t know which one I’m watching. I am familiar with several of the more mature ammonia-based desulfurization processes currently in use in China, and I have had extensive discussions on them. The control of chloride ion concentrations is roughly similar across these processes; some even claim to achieve levels above 100,000, which is somewhat exaggerated. In reality, once the concentration exceeds 60,000, the 1.4529 alloy can no longer handle it – C-276 alloy is required instead, and even C-276 may not be sufficient at levels above 100,000. This post was last edited by yinxh009 on 2008-5-25 18:42.]
Ammonium sulfate crystals do indeed exhibit better wear resistance compared to limestone-gypsum slurry, but this does not mean that there is no wear at all; dust also causes wear on the impeller. Practice has shown that the service life of rubber-lined impellers in ammonia-based desulfurization is not as long, and many have been replaced with all-alloy ones.
The materials chosen are appropriate, so there should be no problems.