Energy-conservation and emission-reduction type active lime calcination method and apparatus

Abstract

An energy-saving and emission-reducing calcining method for preparing active lime. First, the raw material (1) limestone is subjected to particle size classification, and then the limestone is evenly distributed according to the grade and sent to each preheating chamber (8.1) of the new vertical preheater (8). , using high-temperature exhaust gas to preheat and partially decompose it, and then introduce it into the rotary kiln (15), calcinate under the action of the temperature field, and decompose CO2 into lime, and then enter the shaft device (18) for "simmering" and After the heat exchange, it is introduced into the cooling machine (19) for cooling and sieved to separate block lime and powder lime, and then obtain the finished block lime and powder lime. The present invention also provides a particle size classification device (2), a distributor (5), a distribution bin (6), a new vertical preheater (8), a rotary kiln (15), and a kiln head cover (17) for the method. And the device that burner (16), shaft device (18), cooling machine (19) etc. are formed. The particle size of the selected raw material limestone can be relaxed, low heat consumption, high production efficiency, high product activity, low SO2 and waste gas emissions, low cost, easy operation, and can meet the needs of larger industrial production.

Description

technical field [0001] The invention relates to a high-activity lime industrial production method and device with high activity, low energy consumption, low sulfur and waste gas emission. The invention belongs to the field of industrialized lime production, and specifically relates to a method and a device for producing high-activity lime in an industrialized manner by using natural block limestone as a raw material, reducing energy consumption, and reducing sulfur and waste gas emissions. The invention can also be widely used in the heating of granular materials in industries such as building materials, chemical industry and metallurgy. Background technique [0002] So far, there are two methods for producing block active lime: shaft kiln calcination and rotary kiln calcination. Shaft kiln calcination methods can be divided into ordinary old mechanized shaft kiln and modern shaft kiln. Ordinary old-style mechanized shaft kilns have backward technology, high labor intensit...

AI Technical Summary

Problems solved by technology

The disadvantages are: (1) The rate of raw and dead combustion of lime is relatively high

(2) The distribution of limestone in the preheater is uneven, the heat transfer is uneven, and the thermal efficiency is low

Various forms of vertical preheater material receiving areas are located on the inner side of the cross section of the preheater, and the outer space is based on the inner limestone rolling along the angle of repose and then accumulated. The height difference of the layer is very large, the distribution of limestone particle size is uneven, the resistance encountered when the high-temperature exhaust gas from the kiln tail passes through the material layer is greatly different, the distribution of hot air is uneven, and the limestone is heated unevenly

(3) Low pre-decomposition rate

Various forms of vertical preheater discharge are equipped with multiple pushing devices, but limestone can only be pushed into the rotary kiln in sequence. When one pushing device is pushing, other pushing devices are in a waiting state. The more feeding devices, the longer the waiting time; when the pushing device is in the waiting state, the limestone above it is in a static state. As the exchange progresses, the temperature difference between the material and the hot air flow becomes smaller and smaller, and even tends to " Zero", thus slowing down the heat transfer from the limestone surface to the interior, and also reducing the pre-decomposition rate of the preheater

(4) The vibrating vertical cooler adopts multiple vibrating unloading devices to vibrate unloading at the same time. Affected by the difference in vibration frequency, it is difficult to achieve balanced unloading, and it is prone to "heart-pulling" phenomenon, resulting in partial cooling or even red material. The lime is unloaded; at the same time, under the action of the vibration force, the lump lime is easily broken, which reduces the lump lime rate

In addition, the larger the output of the production line, the larger the diameter of the feeding chamber, which brings many technical difficulties to the corresponding support structure and affects the development of larger industrial production.

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