Discussion on the structure of converter furnaces

Is it an evaporative water jacket?

Is it the same as the water seal in a gas holder? When it is full, it flows automatically into the overflow channel~~~ or it evaporates~~ The temperature of the water jacket in a conversion furnace is usually around 50 degrees, so evaporation is less likely to occur; it’s better to return it to the circulating water through the return pipe~

It is generally achieved through the return pipe.

This structure is the one used in the conversion furnaces designed by the Second Institute nowadays; we use the same design. There is no return water, and during normal operation a certain liquid level is maintained. When the liquid level drops, water is added through a self-regulating valve, but only a small amount of water is needed, as the temperature in the water jacket of the conversion furnace is around 50 degrees, making evaporation unlikely. Therefore, it is sufficient to keep water inside during normal operation.

I agree with the view from the 6th floor: the water consumption for the ice jacket is low, and the liquid level can be controlled through automatic control valves. No circuit required

This can be done under normal conditions; the problem is that if defects appear in the inner layer, operations must be stopped for repairs. When cracks are present, more heat is released, which requires more cold water, resulting in high water consumption. Our facility has a recirculation system; the water temperature is controlled at 80 degrees, and the water flow rate is 5–9 T/h. The inner layer is made of castable material. This post was last edited by Chemical Engineering*Beginner Class on 2009-4-21 at 10:21

Thank you, it’s on the 6th floor; that’s probably right

Maintain the overflow level, and pay close attention to the temperature of the water returning to the jacket; it’s best not to let it exceed 50 degrees

The purpose of the water jacket is to reduce the design temperature of the pressure vessel. Firstly, it helps to lower the material requirements for the pressure vessel; secondly, even if the lining inside the pressure vessel is damaged, the evaporation of water in the jacket helps to keep the vessel’s temperature low, thereby preventing any hazards. If the jacket water temperature is maintained at 50 degrees, the amount of water returning will be very large. Otherwise, where does the heat emitted by the housing go? Even if the design temperature of the housing is below 100 degrees, the amount of heat transferred is still considerable. However, if the design temperature of the housing is below 100 degrees, the thickness of the lining will be very large. Conversely, the actual operating temperature of the casing is definitely above 100 degrees. Keeping the jacket water temperature at 50 degrees poses another risk: it can cause the jacket to crack apart from the pressure vessel. This is how it is done at the moment, but it doesn’t mean it’s the correct way. The fact that there is no danger at the moment does not mean it will remain safe forever.

What is the purpose of the overflow port? Is it necessary to connect it to a water return pipe? Does it need to remain open at all times?

The purpose of the water jacket is to reduce the design temperature of the pressure vessel, and secondly, to allow for early detection in the event that the lining is damaged. The existing conversion reactors for producing methanol from coke oven gas are all based on the same design, with very few improvements made, which is why the same problems keep arising. The proper design of a water jacket should ensure that there is no need for overflow, nor for backflow; instead, an exhaust port to the atmosphere should be provided at the top of the jacket, along with an automatic level control system. Under normal conditions, the evaporation rate of the water jacket is limited, generally to around 500 KG/h (this value can be calculated based on the surface area of the furnace and the evaporation temperature). Since it is evaporation at atmospheric pressure, the temperature is around 100 degrees. If the lining is damaged, this can be detected by observing the amount of evaporation; on the instrument, this shows up as a sudden drop in liquid level and a sudden increase in the opening degree of the control valve. From a safety perspective, an interlock shutdown of the converter can be triggered when the jacket liquid level is too low, to prevent equipment failures. These design approaches are also the common practice of foreign companies (such as David and Topsoo). A 50-degree design is incorrect, and overflow leads to water waste. It should be noted that the water used for the jacket should preferably be boiler feed water; at the very least, it should be demineralized water, and under no circumstances should recycled water be used. Furthermore, there are many areas in the structural design of existing methanol conversion reactors using coke oven gas that could be improved. It is necessary to draw on the design concepts of two-stage pure oxygen conversion reactors used abroad; good designs cannot be created by working in isolation. Quantitative analysis is essential (especially for combustion calculations) in order to take targeted actions and prevent accidents such as furnace penetration; the same applies to the calculation of the evaporation rate in water jackets. Only with guidance from quantitative calculation theories can a perfect design be ensured.

The purpose of the water jacket is to reduce the design temperature of the pressure vessel, and secondly, to allow for early detection in the event that the lining is damaged. The existing conversion reactors for producing methanol from coke oven gas are all based on the same design, with very few improvements made, which is why the same problems keep arising. The proper design of a water jacket should ensure that there is no need for overflow, nor for backflow; instead, an exhaust port to the atmosphere should be provided at the top of the jacket, along with an automatic level control system. Under normal conditions, the evaporation rate of the water jacket is limited, generally to around 500 KG/h (this value can be calculated based on the surface area of the furnace and the evaporation temperature). Since it is evaporation at atmospheric pressure, the temperature is around 100 degrees. If the lining is damaged, this can be detected by observing the amount of evaporation; on the instrument, this shows up as a sudden drop in liquid level and a sudden increase in the opening degree of the control valve. From a safety perspective, an interlock shutdown of the converter can be triggered when the jacket liquid level is too low, to prevent equipment failures. These design approaches are also the common practice of foreign companies (such as David and Topsoo). A 50-degree design is incorrect, and overflow leads to water waste. It should be noted that the water used for the jacket should preferably be boiler feed water; at the very least, it should be demineralized water, and under no circumstances should recycled water be used. Furthermore, there are many areas in the structural design of existing methanol conversion reactors using coke oven gas that could be improved. It is necessary to draw on the design concepts of two-stage pure oxygen conversion reactors used abroad; it is impossible to create good designs by working in isolation. Quantitative analysis is essential (especially for combustion calculations) in order to take targeted actions and prevent accidents such as furnace penetration; the same applies to the calculation of the evaporation rate in water jackets. Only with guidance from quantitative calculation theories can a perfect design be ensured.

It was designed by the Second Chemical Engineering Institute. But there is backflow. In the absence of backflow, the liquid level should be kept stable with a small amount of overflow.