1、 Overview

Long ago, people knew how to burn lime and build lime kilns. However, for many centuries, there has been no significant improvement in lime calcination technology. The production method of primitive earth kilns is still used today, which not only consumes a large amount of fuel, but also has low production and quality, high labor intensity, and very poor operating conditions. In response to this situation, our company is committed to the purpose of changing this situation. After more than ten years of research and practical testing and summary of over 100 mechanized vertical kilns, combined with the experience of advanced mechanized vertical kilns abroad, we have designed the F550 mechanized vertical kiln lime production line system, which has the advanced level in the domestic lime kiln industry today. The production line works stably, is environmentally friendly, energy-saving, operates simply, reliably, and has simple equipment, And the investment is low.

Four production lines are proposed for the 100000 ton lime powder production line of this project, including one batching and feeding system, four lime kilns, six lime storage silos, four kiln gas and water bath dust removal and desulfurization systems, and four automated control systems.

2、 Main economic and technical indicators

1. Lime kiln volume: 550m3

2. Daily single kiln output: 350T-370T

3. Heat consumption: 125kg · standard coal/ton of lime

4. Utilization coefficient: 0.65-0.72

5. Lime activity: (ml): 280 ～ 360

6. Lime CaO (%): 85-92

7. Lime calcination rate (%): 5-10

8. Limestone consumption (t/t · ash): 1.7

9. Smoke and dust emission index after water bath dust removal (mg/Nm3): less than 30

10. Electricity consumption: 12-20 kWh/ton of ash

11. 6 operators per shift

3、 Main parameters of kiln

1. Total height of kiln: 40 meters

2. Kiln shell outer diameter: 6.79 meters

3. Maximum inner diameter of kiln: 5.3 meters

4. Kiln volume: 550 cubic meters

5. Kiln shell steel plate thickness: 12mm

6. Air supply method: ventilation under the kiln without a hood

7. Batching measurement method: measuring with a measuring hopper

8. Loading method: inclined frame trolley

6. Fabric method: high-speed rotating fabric machine for fabric distribution

7. Ash discharge: Four point discharge of the disc ash discharge machine

8. Kiln gas dust removal: water bath wet dust removal and desulfurization

4、 Raw material conditions

(1) High quality limestone: 50-80 mm or 60-90 mm, CaO ≥ 53%, clean and free of soil, with uniform particle size and consistent stone quality.

⑵ anthracite: calorific value ≥ 6500kcal/kg; Volatile content is about 6%, ash content is less than 13%, and particle size is 10-30mm.

5、 Measures Taken to Eliminate Furnace Misfire in F550 Mechanized Lime Production Line

1. Air supply without hood is adopted to make the lime kiln ventilation soft, lime cooling sufficient, the produced lime is calcined evenly and uniformly, the product quality is stable, and the activity is high; At the same time, the most important thing is that the use of air supply without a hood has greatly improved the ventilation of the kiln center, resulting in a uniform and balanced rise of the fire layer in the lime kiln, and greatly improving the uniformity of lime calcination.

2. The windless hood grate eliminates the major hidden danger of uneven ash discharge from the kiln and one of the hidden dangers of furnace misfire.

5、 Measures Taken to Eliminate Furnace Misfire in F550 Mechanized Lime Production Line

3. Design a dedicated non-standard ventilation fan according to different purposes, so that the wind pressure and air volume of the fan match the needs of the kiln. Excessive wind pressure can also cause the kiln to overheat.

4. The lime kiln adopts a disc ash extractor for multi-point ash discharge, which reduces the balance of materials in the kiln during ash discharge, eliminates the problem of ash deviation from the kiln, and improves the stability of the kiln's operation.

5. Adopting the most advanced domestic automatic distribution machine designed by oneself, the mixed coal and stone are distributed into the kiln in the most reasonable way; After the ignition and debugging of the kiln are normal, it can maintain the kiln without deviation for a long time, thus enabling the operation of the kiln to be automated.

5、 Measures Taken to Eliminate Furnace Misfire in F550 Mechanized Lime Production Line

6. The kiln belt adopts thermoelectric coupling for monitoring, enabling the kiln to achieve dark fire operation. This can greatly reduce the temperature of the kiln gas, greatly reduce the heat carried away by the kiln gas, and achieve energy-saving in the kiln. At the same time, timely detection and correction of kiln misfire can be achieved.

6、 Lime production process flow

The lime production line consists of a raw material (fuel) storage system, a batching system, a feeding system, a distribution system, a kiln calcination system, an ash discharge system, a storage bin, lime processing, dust removal system, and automation control.