How to deal with overheating in a converter?

May I ask the original poster: are your shift converters used in ammonia synthesis or methanol plants to convert CO into CO2? If so, the following actions should be taken in case of overheating: First, reduce the load appropriately to decrease the absolute amount of CO entering the converter. Second, increase the steam volume appropriately; since steam has high thermal conductivity, it can carry away some of the heat. Third, the oxygen content entering the converter must be strictly controlled. If the oxygen content is high, the shift catalyst is prone to overheating. Fourth, identify the cause of the overheating in a timely manner and take appropriate measures. This post was last edited by lxq700918 on 2009-2-13 18:07.]

It depends on whether the oxygen content in the gas is high; one also needs to check the humidity of the gas as it exits the saturation tower. If the temperature doesn’t change much, adding steam will suffice

During normal production, overheating of the converter is generally caused by high oxygen content or improper adjustment. In cases of high oxygen content, it is necessary to reduce production load appropriately, while simultaneously contacting the gas generation unit to lower the oxygen content ； In the case of overheating caused by regulation issues, it is necessary to adjust the amount of steam added and the amount of water used for humidification promptly.

The shift reaction is a highly exothermic reaction; as the reaction proceeds, the gas temperature continues to rise. However, the optimal reaction temperature gradually decreases as the conversion rate increases. Therefore, in order to increase the conversion rate and enable the reaction to proceed at the optimal temperature, it is necessary to continuously remove the heat of reaction, thereby keeping the temperature low as the reaction progresses. Secondly, the heat resistance of the catalyst itself has certain limits; to prevent the catalyst layer from overheating, it is also necessary to remove the heat generated by the reaction in a timely manner. It is actually extremely difficult to ensure that the reaction proceeds entirely at the most optimal temperature. In industry, the segmented conversion method is used to address this issue; conversion furnaces are generally divided into three sections. That is, the first stage undergoes an almost adiabatic transformation reaction at a higher temperature, in order to achieve a faster reaction rate and improve catalyst utilization ； Then intermediate cooling is carried out ； The second stage continues to react at a lower temperature, with cooling taking place between the stages ； The reaction temperature in the third paragraph is lower. There are mainly two methods for cooling through intercooling: **the direct quenching method and the indirect heat exchange method using a heat exchanger. **During cold shock cooling, due to the high latent heat of vaporization of water, only a small amount of water is needed to achieve cooling, which increases the water vapor content in the gas and reduces the consumption of externally supplied steam; as a result, the system resistance is low. However, the structure of the converter is relatively complex. The medium-string low-flow process and the fully low-temperature shift process without saturation towers generally employ the **cold shock method**. The all-low-temperature conversion process uses indirect heat exchange. Since the gas-steam ratio in the full-low conversion process is low, the amount of steam remaining after the reaction is minimal, resulting in a very low dew point temperature of the conversion gas. In this case, if hot water is used to raise the temperature only through a single water heater, it will not be possible to meet the requirements for the water temperature at the inlet of the saturation tower. Therefore, in the full low-temperature conversion process, after passing through the first water heater, the hot water exchanges heat with the gas coming out of the second conversion stage via the second water heater; it then exchanges heat with the gas coming out of the first conversion stage through the temperature-regulating water heater. Through multiple stages of heat exchange, the temperature of the water entering the saturation tower is increased, allowing more water vapor to be saturated in the semi-water gas within the saturation tower and thereby reducing the amount of steam that needs to be supplied from outside. For similar reasons, the medium-low-low process also employs indirect heat exchange.