A low-temperature heat recovery device for sulfuric acid and a process for producing low-pressure steam using it

Abstract

The invention provides a low-temperature sulfuric acid heat recycling device and a process for producing low-pressure steam by using the device, belonging to the technical field of low-temperature heat utilization. The low-temperature sulfuric acid heat recycling device provided by the invention consists of a low-temperature heat recycler and a uniform mixer. The device can be used for recycling low-temperature heat and generating low-pressure steam by using the low-temperature heat in the sulfuric acid industry. The device has the beneficial effects that the low-temperature sulfuric acid heat recycling device provided by the invention is low in manufacturing cost, safe to operate and wide in applicable sulfuric acid concentration range, and can be applied to processes with large sulfuric acid absorption temperature difference. When the device is used for generating low-pressure steam, the low-temperature heat utilization rate in the conventional sulfuric acid production can be increased to be greater than 99%.

Description

technical field [0001] The invention belongs to the technical field of low-temperature heat utilization, and in particular relates to a sulfuric acid low-temperature heat recovery device and a process for producing low-pressure steam by using the same. Background technique [0002] The production of sulfuric acid from sulfur mainly involves three steps: sulfur incineration, sulfur dioxide conversion and sulfur trioxide absorption. The above three processes are all exothermic reactions. The first two steps generate high and medium temperature potential heat, which is recovered through a series of heat exchangers such as waste heat boilers and high temperature superheaters, and can produce sub-high pressure or medium pressure steam. For the third step, the temperature of reaction heat released by sulfur trioxide absorption is too low, traditional equipment and processes cannot be used to produce steam, and the heat generated is lost to the environment through circulating cooli...

AI Technical Summary

Problems solved by technology

However, in order to ensure the recovery efficiency of low-temperature heat, the material and structure of the equipment used are extremely demanding, and complex piping and control systems need to be set up to strictly control the concentration and temperature of sulfuric acid. This will increase investment on the one hand, and lead to Technical problems such as difficult control of process conditions; in the process of utilizing low-temperature heat, the HRS boiler used by Monsanto Environmental Chemical Company of the United States occupies a large area and is expensive, which is not conducive to cost control

At the same time, the internal structure of the HRS boiler is complex, difficult to process and repair, and the operating conditions are harsh, and it replaces the absorption tower acid cooler of the traditional process. In particular, it needs to use process gas to superheat the steam to increase the temperature of the heat energy. The process is complex

The developed technology does not form an independent system, it is not suitable for the transformation of old factories, and it is difficult to adapt to the market development trend for the construction of new factories

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