Low-pressure steam generator

Abstract

The invention provides a low-pressure steam generator. The steam generator comprises a housing provided with openings at the upper and lower ends, a shell side inlet, a shell side outlet, an upper tube plate arranged at the opening at the upper end of the housing, and a lower tube plate arranged at the opening at the lower end of the housing. An upper head is arranged above the upper tube plate, and a lower head is arranged below the lower tube plate. A heat exchange tube set is arranged between the upper and lower tube plates and is vertically disposed inside the chamber of the housing. The steam generator also comprises a tube side inlet and a tube side outlet. A tube plate thermal insulation layer is arranged on the upper surface of the upper tube plate. The inner tube wall at the upper end of each heat exchange tube is provided with a heat exchange tube thermal insulation layer, the heat exchange tube thermal insulation layer is internally provided with a sleeving, and the upper end of the sleeving protrudes from the heat exchange tube and is disposed inside a through hole in the tube plate thermal insulation layer in a penetrating manner. The steam generator is provided with the tube plate thermal insulation layer and the heat exchange tube thermal insulation layers, so that the tube plates and heat exchange tube materials can be effectively prevented from being thermally eroded by tube side high-temperature mediums, the temperature of the tube plates and the heat exchange tubes is reduced, and the temperature of the tube plates and the heat exchange tubes can be controlled within the using temperature range of the used materials.

Description

technical field [0001] The invention relates to the technical field of steam generators, in particular to a steam generator used in coal-to-methanol production of olefins. Background technique [0002] As a basic chemical material that can form many other materials, olefins have been used as an important basis for measuring the national chemical industry level. Olefins are mainly produced from petroleum cracking. Due to the increasing shortage of petroleum production in my country, the production of olefins that rely on petroleum is even more insufficient. Therefore, the coal chemical industry of coal-to-methanol production of olefins has emerged as the times require. [0003] Steam generator is an indispensable equipment for energy saving and waste heat recovery in the petrochemical industry, and also plays a very important role in coal chemical projects. Conventional steam generators can no longer meet the requirements for heat exchange in coal chemical projects. It is di...

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Problems solved by technology

[0007] Again, the shell side of the steam generator is the cold medium boiler feed water, and the tube side is the hot medium process gas. The process gas contains catalyst powder. Due to the poor fluidity of the powder, it is easy to flow in the tube in the environment with steam or water. Fouling, and then the efficiency of the steam generator will be greatly reduced

When cleaning the dirt in the pipe, the whole device needs to be shut down, so the continuous operation time of the equipment is short, which affects the production capacity

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