Preheater of synthesis ammonia raw material gas

Abstract

The invention discloses a preheater of synthesis ammonia raw material gas. The preheater comprises a shell and a plurality of groups of coil tube bundles which are arranged in the shell; the shell is of a rectangular tube structure comprising a top plate, a bottom plate, a left side plate and a right side plate; a heat-insulation layer is lined on the inner wall of the shell; the plurality of groups of coil tube bundles are vertically arranged along the shell in parallel, and are supported in the shell through a pipe plate; the raw material gas inlet and raw material gas outlet of each bundleare arranged at the same side plate of the shell; the top plate, the bottom plate and the heat-insulation layer are combined structures of a plurality of prefabricated modules; each prefabricated module is composed of a steel structure and a heat-insulation material poured in the steel structure; the steel structure is of an open box shape; the heat-insulation material is poured in the open box; the number of the prefabricated modules is the same with that of the tube bundles; each prefabricated module is corresponding with one group of tube bundles; the adjacent prefabricated modules are connected through connection pieces; the heat-insulation material is arranged in a joint; and the heat-insulation material is also poured in the inner walls of two side plates. The preheater has the beneficial effects that the manufacturing difficulty of the device is reduced, and the construction cycle is shortened; the overhaul cycle is shortened greatly, and the valid working days are prolonged; and the heat-insulation layer is poured and molded and is seamless, and the heat insulation effect is much better.

Description

technical field [0001] The invention relates to a heat exchanger, in particular to a preheating device for synthetic ammonia feed gas. Background technique [0002] The raw material gas for ammonia synthesis is a mixture of air and natural gas (or coal gas). Before the conversion of the raw gas, it needs to be preheated to a temperature suitable for conversion. It is then sent to the conversion furnace to continue heating and conversion. The existing raw material gas preheating device includes a shell and multiple sets of coil tube bundles arranged in the shell. The shell is composed of a top plate, a bottom plate, and left and right side plates to form a rectangular tube structure. The two ends of the shell are respectively The inlet and outlet of the flue gas, and the outlet is drawn by an induced fan. The multiple groups of tube bundles are arranged side by side along the longitudinal direction of the shell, and are supported in the shell by the tube plate. The raw mater...

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Problems solved by technology

The problem is that since the shell is an integral structure welded by steel plates, the heat insulation layer has to be built with refractory bricks. On the one hand, the joints of the bricks reduce the heat insulation effect; The construction is difficult, the efficiency is low, and the processing cycle of the device is too long; especially, when repairing or replacing the tube bundle, all the heat insulation layers need to be removed and rebuilt, resulting in long repair time and shortening the effective working days of the enterprise , and the maintenance cost is high

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