Preheating or heating casing temperature measuring device in alumina production

Abstract

The invention discloses a preheating or heating casing temperature measuring device in alumina production. A temperature measuring resistor is installed on a straight pipe section between an inner pipe plug of a casing and a variable diameter of the casing, and abuts against the straight pipe section. The temperature measuring resistor is arranged in a protective box. The gap between the temperature measuring resistor and the inner wall of the protective box is filled with a thermal insulation material. The protective box is fixed on the straight pipe section. A connecting flange is arranged on the outermost side of the protective box. The integrity of the temperature measuring element can be protected. The impact of environmental factors on the temperature measurement results can be reduced. The accuracy of temperature measurement of the materials at the inlet and outlet of the casing can be improved. Compared with the common installation mode, the error can be reduced by 7-10 DEG C.The accuracy of judgment on production by operators can be reduced. Therefore, energy can be saved.

Description

technical field [0001] The invention relates to a temperature measurement technology in alumina production, in particular to a temperature measurement device for preheating or heating sleeves. Background technique [0002] During the production of alumina by the Bayer process, many processes use casing preheating and heating, including pre-desiliconized pulp, pressure-cooked leached pulp, and evaporated mother liquor for alkali washing. At present, the temperature of the material in and out of the bushing is measured by a patch thermal resistance on the surface of the bushing, and the patch temperature sensor is attached to the surface of the bushing by screws or magnets. The installation method of this patch type thermal resistance is greatly affected by the surrounding environmental factors, such as the insulation damage of the casing, and the ambient temperature will cause a large error in the temperature measurement result. The general error is about 10°C, and some error...

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Problems solved by technology

The installation method of this patch type thermal resistance is greatly affected by the surrounding environmental factors, such as the insulation damage of the casing, and the ambient temperature will cause a large error in the temperature measurement result. The general error is about 10°C, and some errors can reach more than 20°C. On-site operators cannot accurately judge the pre-desilication temperature or dissolution temperature, etc. When the temperature is not enough, excess steam may be introduced, resulting in waste of steam

In addition, the installation method of this patch thermal resistance is easy to be damaged during maintenance, causing economic losses and affecting production and operation.

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