Regarding the manhole on the converter
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1. The manholes on sulfur dioxide converters are designed to be welded; when replacing the catalyst, it is necessary to cut them open, which is quite difficult. Why aren’t they designed with flange connections? 2. It is necessary to modify each heat exchanger, especially Exchangers 3 and 4. The access holes at the bottom of these exchangers are also welded; sometimes there is condensed acid at the bottom along with acidic sludge, which makes cleaning difficult. In such cases, cutting is required, which is quite troublesome. Is it possible to replace those welded access holes with ones that use flange connections? I hope the experts here can give me some advice! Thank you
This is a traditional design; it may be related to the insufficient material properties of the gaskets used back then.
This is a traditional design; it may be related to the insufficient material properties of the gaskets used back then.
This post was last edited by boqing_zh on 2020-12-15 at 11:27. It is a traditional design; perhaps it is related to the insufficient (temperature-resistant) properties of the gasket material used back then. There are now a wide variety of high-temperature resistant gaskets available, which can be used in place of flange manholes. The manholes of a company’s WSA wet acid production plant have always been designed to be flanged type. If the material’s temperature resistance is below 500°C, it can be considered to replace only the manholes at each inlet section with flanged types.
Flange connections have relatively poor sealing performance, and leaks are very difficult to deal with once they occur
Changing it to carbon steel welding makes it easier to cut than stainless steel.
You can’t put it that way; there are cases where flanges don’t leak, but welding can still result in leaks. Cars pose a greater risk of accidents on the roads, but that doesn’t mean we should stop them from being used on roads
This is a flange; it’s difficult to deal with leaks if they occur
It turns out that the sulfuric acid production capacity is low and the process parameters are not well controlled; therefore, the catalyst has to be removed and screened almost every year, and catalysts that are easy to disassemble are generally chosen； Now that the process parameters are well controlled, screening is done only once every 3 years or more; welding is much more reliable than flanges ； Furthermore, a sulfur dioxide alarm device needs to be installed at the flange, which increases the requirements for routine maintenance.