Combined tube heat exchange device for alumina decomposition tank and cooling method

Abstract

The invention provides a combined tube heat exchange device for an alumina decomposition tank and a cooling method, and relates to the field of metallurgical alumina production. The combined tube heatexchange device comprises a plurality of shell-and-tube heat exchangers, each shell-and-tube heat exchanger is provided with a shell, the two ends of each shell are provided with sealing heads, tubeplates arranged at the connection positions of the sealing heads and the shells, each sealing head and the corresponding tube plate define a tube box, and a plurality of heat exchange tubes are arranged side by side between every two corresponding tube plates; and the heat exchange tubes are seamless steel tubes, the two ends of each heat exchange tube are in expansion connection to the corresponding tube plates, and the side walls of the two ends of each shell are respectively provided with a cooling water inlet and a cooling water outlet. Every two corresponding sealing heads are provided with a slurry inlet and a slurry outlet correspondingly, and the multiple shell-and-tube heat exchangers are connected in series and / or in parallel. By means of the combined tube heat exchange device for the alumina decomposition tank and the cooling method, the local abrasion problem in the heat exchange device can be effectively eliminated, and the service life of the heat exchange device can be prolonged.

Description

technical field [0001] The invention relates to the field of metallurgical alumina production, in particular to a combined tube and tube heat exchange device and cooling method for an alumina decomposition tank used for cooling slurry in a decomposition tank during the alumina production process. Background technique [0002] In the existing metallurgical alumina production line, the cooling of the slurry in the decomposition tank needs to be carried out through a heat exchanger. This technology is a common practice in the production of alumina by the Bayer process in China and has been used for decades. The technical solution is to send part of the slurry in the decomposition tank to the heat exchanger through a centrifugal pump, exchange heat with low-temperature circulating water for cooling, and then return the low-temperature slurry to the decomposition tank to achieve overall cooling by stirring. Since the slurry is a supersaturated sodium aluminate solution containing...

AI Technical Summary

Problems solved by technology

Since the plate needs to be installed inside the heat exchanger through the positioning column, the slurry will form a local flow velocity change at the positioning column, and the plate part and the positioning column are prone to abrasion problems, and the service life is limited; secondly, there are also problems in the plate heat exchanger The weld seam is severely fragile after repeated alkali cleaning; finally, the plate heat exchanger needs to be hoisted as a whole, and the weight of the equipment makes it difficult to hoist

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