The function of the start-up heater in transformation

Used for heating during catalyst replacement sulfiding

Is it also needed when the system is cooled down?

Yes, it is also used to rapidly lower the temperature of the conversion furnace, but no nitrogen heating is required

Then there’s no need to heat the nitrogen; why then go through the process of passing it through the startup heater? I just don’t understand this

At the beginning of catalyst sulfidation, it is necessary to raise the temperature; after that, the temperature needs to be lowered again. The heating process must be followed strictly, and once the temperature drops to around 200 degrees, it is necessary to maintain that temperature for a certain period of time – perhaps this is the purpose behind it.

;P What are the consequences of the sudden drop in process gas temperature and condensation after normal-temperature nitrogen enters the system?

The last edit to this post was made by 654262293 on 2016-4-18 at 10:43. Hold on a moment; I’ll get back to you. There are several main reasons why it’s necessary to use a startup heater when the temperature drops: 1. If a startup heater is not used, then when cold nitrogen enters the converter, the thermal pressure resulting from the large temperature difference can severely damage the strength of the catalyst, and in severe cases, the catalyst may even break apart. 2. After the catalyst sulfidation is complete, if a start-up heater is not used, the entry of cold nitrogen into the shift converter will cause the temperature of the catalyst in the upper part to drop below its activation temperature, while the temperature in the lower part of the catalyst bed remains very high. It is not possible to follow the cooling curve properly. 3. If a start-up heater is not used, when cold nitrogen enters the converter, if the nitrogen is not dry but contains a certain amount of moisture, this will cause condensate to enter the catalyst bed, leading to caking of the catalyst and, in severe cases, its agglomeration. The consequence of this is a decline in catalyst activity.

I’ve learned it; it’s because of short-term parking at my workplace – that’s exactly what I did. Next time there is a situation of short-term parking, I’ll suggest it to my supervisor, but whether it will be accepted is unknown

1. Do you mean the heating furnace that starts up at the transformation inlet? It is used to prevent liquid water from forming due to low gas temperature while driving, so as to avoid it entering the shift converter and causing the catalyst to break down ； 2. Parking to cool down and then heating the nitrogen is intended to prevent a large temperature difference between the cold nitrogen and the catalyst bed; such a difference could cause the catalyst to crack upon entering the furnace suddenly.