What are the advantages and disadvantages of converter furnaces with an internal insulation lining versus those without one?
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What are the advantages and disadvantages of converter furnaces with an internal insulation lining versus those without one?
It has a lining; the material for the equipment casing can be something like 16Mn, which will meet the requirements. The thickness of the equipment walls is not very great, but the lining is sensitive to water (liquid water)； Without lining, the equipment housing needs to be made of materials such as 387, resulting in a thicker furnace wall.
I agree with the view from the second floor: installing internal insulation allows for the use of lower-grade materials for the shell of the converter (especially medium-frequency converters), as well as a reduction in the wall thickness; meanwhile, the thickness of the external insulation on the converter can also be reduced； The disadvantage is that it reduces the volume of the converter and the amount of catalyst required. I have never seen a converter without internal insulation.
Internal insulation in the converter reduces the requirements for the converter’s material while also minimizing heat loss. There are high requirements regarding the use of internal insulation materials; otherwise, high temperatures and pressures can easily cause the converter to bulge or deform, posing a danger. In addition to the points mentioned above, another significant drawback is that once the internal insulation is damaged and large cracks appear, gas can flow in a short circuit around the catalyst bed, resulting in an increase in CO levels at the outlet or making it difficult to control the situation, which poses challenges for operation.
Another advantage of installing internal insulation is its excellent heat-insulating effect; this allows the active temperature of the shift catalyst to be maintained for an extended period of time while the plant is shut down. We use a fully low-temperature shift process, and during shutdown, it is possible to operate the system for up to 7 days without the need to raise the temperature. It is sufficient to preheat the equipment and pipelines leading to the shift reactor in order to start up the system by introducing gas. I wonder if everyone agrees?
In medium-voltage conversion units, some conversion furnaces are not equipped with internal insulation; the equipment is made of 15CrMoR material, and its wall thickness is relatively large. The reasons for not including internal insulation are, first, corrosion, second, pressure resistance, and third, a reduced amount of catalyst that can be used. As for parking and heat preservation, if the external insulation of the equipment is properly done, the heat preservation effect will be fairly good
This post was last edited and replied to by 654262293 on 2010-6-21 at 12:36. Reply 6# cicala: In medium-voltage conversion units, many of the conversion furnaces are equipped with internal insulation; external insulation provides a much poorer level of insulation. Our two conversion furnaces originally used medium-series low voltage, but were upgraded to full low-voltage conversion in 1995. The first conversion furnace is equipped with internal insulation, while the second conversion furnace was modified from a zinc oxide desulfurization tank; it lacks internal insulation and only has external insulation. During the shutdown period, the first shift converter maintained good heat retention, while the second shift converter had much poorer heat retention, and its bed temperature dropped rapidly.
Reply to 7# 654262293: I want to know what the inlet pressure remains at after you modify the system to use all low-pressure transformers What is the operating temperature of a low-temperature transformer?
Reply to 8# 892187063: The inlet pressure of the full low-pressure transformation system in our old plant is 2.05 MPa. The first transformation stage is divided into two sections; the inlet temperature for the first section is around 215 degrees, while that for the second section is around 230 degrees. The inlet temperature for the second transformation stage is around 210 degrees.
Our shift conversion process is still of the medium-low-low conversion type; the pressure at the inlet of the conversion unit is 0.8 MPa, while it is 0.7 MPa at the outlet. The medium-low conversion units are connected in series, with internal and external insulation in place. The insulation layer inside the medium conversion furnace has fallen off, and cracks often appear in the tower walls during the cold shock stage, leading to air leakage – this is caused by the alternating application of warm and cold water. The converter material is 16MnR. It’s better after you’ve made the modifications. Haha