New type of natural gas fired lime

Design Specification for Intelligent Production Line (250 tons/day)

Type F 200 type intelligent pulverized coal spraying lime kiln

 The lime kiln is set as: pre-tropical, calcined zone, temperature preservation zone and cooling zone (compared with the traditional lime kiln).

Pre-tropical: the role of pre-tropical is to use the high temperature flue gas from calcined to preheat the limestone to enter the calcination belt in advance. ① can make full use of the heat energy and reduce the production cost ② can speed up the production of the kiln and improve the output (utilization rate) of the kiln.

 Calcination belt: the calcination belt is equipped with three layers of annular furnace and three layers of surrounding burner (burner). The furnace wall is designed as wave, and the central material in the kiln drops faster than the surrounding area, which makes the materials in the kiln roll and mix in the kiln, and also increases the uniformity of lime calcination

 When the calcined limestone reaches above the decomposition temperature, the carbon dioxide decomposes from the limestone, and the limestone block becomes lime.

 Temperature zone: the effect of temperature zone is made from the calcination with high temperature lime not because the cooling wind through too fast cooling, ① calcination with high temperature lime in temperature zone continue to decompose incomplete decomposition of calcium carbonate, make its decomposition, lime quality improvement (lime, burn, effective calcium) ② energy saving ③ product quality is stable.

 Since the lime leaves the calcination zone from the cooling zone, the existing waste heat of the high temperature lime just extracted from the calcination is used to make the lime fully decomposed in the temperature zone for 8.4 hours, so as to reduce the lime and improve the quality of the lime, and also make full use of the waste heat to reduce the fuel consumption.

 Reduce the diameter of the calcined belt to ensure that the high temperature flame can penetrate through the material center in the kiln.

 A separate cooling area is set up to ensure that the lime that needs to be cooled is urgently cooled to improve the activity of the lime. There is as much lime as it needs to be cooled, and there is no rush to cool it.

7, the use of long flame jet PWM control nozzle, in the realization of accurate temperature control, but also to ensure the penetration of the flame, improve the uniformity of the furnace temperature.

8. The lime kiln adopts the disk ash out machine to continuously produce ash, which makes the materials in the kiln drop and balance, eliminates the disadvantages of ash out kiln, and improves the stability of the kiln work.

9. High temperature kiln gas is used for blue carbon drying after dust removal by cyclone dust collector to achieve the purpose of comprehensive utilization and energy saving.

10. Adopt inverted cone cloth; the kiln can keep the kiln not too hot for a long time after normal ignition debugging, so that the automation of the kiln operation can be realized.

2. Main technical parameters

1. Volume of a single lime kiln: 200m³

2. Daily output of single kiln: 200~250T

3, heat consumption: 110~115 kg of standard coal / ton of lime

4. Utilization coefficient: 1-1.5

5. Activity of lime: (ml): 360~440

6. Lime CaO (%): 85-92 (depending on the calcium content of Party A)

7, lime burning rate (%): raw burning rate is less than 5%, over-burning rate is <2%

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

9. Power consumption: 20 degrees Celsius / ton of ash

3. Main parameters of the kiln

1. Total height of the kiln: 34.2 meters

2. Outer diameter of the kiln shell: 4.94 meters

3, the pre-tropical inner diameter of the kiln: 3.63 meters, the volume of 57 cubic meters

4. Internal diameter of kiln calcination belt: 3.1 meters, volume of 54 cubic meters (4 cycles per day)

5, the inner diameter of the kiln temperature protection belt: 3.45 meters, the volume of 70 cubic meters

6, Volume of kiln cooling belt: 14 cubic meters

7, the kiln middle bin volume: 9 cubic meters

8, Total volume of the kiln: 204 cubic meters

9, kiln shell steel plate thickness: 10 mm

10, batching measurement method: measuring bucket measurement

11. Charging mode: inclined frame trolley

12, ash: disk out of the ash machine four uninterrupted ash

13. Kiln gas dust removal: enter the cyclone dust collector through the diameter 770 stainless steel pipeline to remove coarse dust particles, and pass into the water film dust collector after dust removal.

4. Raw material conditions

⑴ High quality limestone: 40~70 ㎜ or 50~80 ㎜, CaO content of 53%, clean and no soil, uniform particle size, consistent stone, no impurities.

⑵ Natural gas: it is 8500~9200 kcal / Standard m ³; the fluctuation range of low heat rate is <2%; the impurity content meets the national standard.

5. Special process and energy saving measures of the F 200 type intelligent natural gas burning vertical kiln

1, the lime production line using automatic control system operation, lime kiln all ventilators using frequency conversion speed control, kiln gas thermocouple monitoring, in order to reduce fuel consumption, make full use of exhaust waste heat, appropriate increase tropical volume using exhaust waste heat preheating just into the kiln limestone, reducing kiln gas away heat, in order to achieve the purpose of energy saving.

2. The calcination belt of the furnace wall adopts one layer of 345 mm thick low creep, high aluminum brick (DRL-145), One layer of 345 mm thick three-grade high aluminum brick (ZL-55), one layer of 345 mm thick two-grade high aluminum brick (ZL-65), 100% of 230 mm thick clay refractory brick (PN-42) + clay refractory castings, An insulation layer of 280 mm thick light castings, Add 30mm thick heat insulation refractory fiber + 3 layers of 10 mm thick asbestos board four layers of comprehensive thermal insulation system, Greatly strengthened the thermal insulation effect of the kiln, The above measures can effectively prevent the heat loss in the calcined area of the lime kiln, Thus, the energy-saving effect of the kiln is achieved.

6. Specific measures to improve the quality of lime (raw and over-burning rate, active degree)

1. There is no hood in the center of the kiln, the material center in the kiln drops faster than the surrounding, the center of the kiln is loose, and the void rate is high, which is convenient for the high temperature flame penetration, so as to make the lime calcination uniform.

7. Lime production process

The lime production line is composed of raw material storage system, batching system, feeding system, kiln calcination system, temperature control system, ash discharge system, storage system, dust removal system and automatic control.

Viii. Supporting the main process and equipment

 Nine, lime kiln dust removal, noise prevention system

1. High temperature flue gas of lime kiln accumulates diameter 770 mm cyclone dust collector to remove coarse particle dust smoke fan water film dust collector, the flue gas treatment capacity of 30,000 cubic meters per hour.

2. A small amount of dust from the tray and ash machine of the belt under the kiln, and the post of the lifting machine room is directly removed through the cooling fan under the kiln, enters the cooling area in the kiln, and is sent to the upper pre-tropical part of the lime kiln through the induced air duct.

3. The unloading area of the limestone floor warehouse shall be sealed by spray dust removal + the workshop.

4. The batching noise of lime kiln adopts the drop point accumulation method + workshop sealing method to reduce and isolate the batching noise.

5. The kiln surface unloading noise adopts the landing point accumulation method to reduce the unloading noise.

6. The noise of the ventilation fan is sealed by the workshop building to reduce and isolate the noise.

7. The noise of other equipment is isolated to reduce the noise.

8. Environmental noise is 65 decibels in the day and 55 decibels at night.

9. No wastewater discharge from the lime kiln production system; the site drainage enters the total sewage collection tank and is supplied to the dust removal system after precipitation. The wastewater is not discharged.

 Ten, the lime kiln batching system

1. 40~70 ㎜ limestone by car to the volume of 160 tons of stone warehouse, limestone in the vibration feeder into B65015 m large inclination belt machine, and then into the single layer of stone strip sieve sieve soil and small particle stone (washing), qualified stone into the volume of 1.5m³ limestone electronic metering bucket measurement, reach 1.7 tons of weight after electronic scale signal to the computer, computer received the signal immediately to the limestone belt machine stop instruction, vibration feeder, belt machine and vibration sieve immediately stop operation, limestone measurement completed.

2. The screened mud and small particles of limestone are through chute and sent to the waste pool for disposal.

 Xi. Limestone lifting system

The limestone in the limestone measuring bucket is also sent into the 1.5m³ feeding trolley through the belt feeder, and the car lifts the stone to the top of the kiln and pours into the top bin of the kiln. The stone in the top bin of the kiln is controlled through the material level meter. The bin is connected with the lime kiln and the height of the material surface in the kiln is guaranteed.

 XII. Combustion control system

Combustion and smoke exhaust system This system is calcium carbide exhaust and combustion air transmission to the jet nozzle mixed combustion, heating stone. This burner combustion adopts automatic ignition, flame monitoring, PWM pulse regulation and control mode. The whole furnace is divided into 9 temperature control sections (preheating 1 layer, heating 3 (layer) section, and heat average area 2 (layer) section.

Gas pipeline configuration: gas main pipeline: manual ball valve, pressure detection, flow detection device and pipeline composition. Gas section pipeline: composed of manual cut-off valve, filter, reduced pressure regulator valve, high and low pressure pressure switch, safe cut-off solenoid valve and pipeline, etc. A. Pipe before burner nozzle: manual cut-off valve, gas solenoid valve, manual regulating valve, burner nozzle (including ignition detection electrode) and pipeline. Manual cut-off valve is used during maintenance and maintenance. The gas manual regulating valve is used during commissioning.b. Air pipe configuration: the air pipe is composed of combustion fan and inlet pressure regulating valve, pressure switch, air solenoid valve and manual regulating valve and pipeline, etc. Comradler: 1, flow 10000 m3/h, full pressure 10 kPa, power 90 kW.c. Ignition control system configuration: the automatic ignition control system consists of ignition transformer, automatic ignition controller, etc.d. Smoke exhaust system configuration: the smoke exhaust system is composed of the kiln top flue gas collection pipe, induced draft fan, etc. Introduced draft fan: 1 set, AC frequency conversion speed regulation.e. Temperature control system configuration: the temperature control system consists of a thermocouple, a transmitter, a PLC (or pulse controller), etc.(Pulse controller function can be realized through PLC programming)

 The lime kiln calcination system

 After limestone into the kiln, as the lime kiln ash, from the kiln pretropical (after 6.8 hours) into the calcination belt, calcination belt into three layers of burner heating furnace, each layer of eight burner cloth along the circumference, the lower burner to take dislocation arrangement, limestone from into the calcination to the calcination belt (6.4 hours), process after heating in the calcination belt, tumbling, decomposition, heat preservation repeatedly three times to make its full decomposition, achieve calcination evenly.

 In order to ensure the quality of lime, a thermal insulation zone is added between the calcination zone and the cooling zone, so that the high temperature lime just out of the calcination belt is rolled and braised for 8.4 hours in the temperature zone, so as to ensure that a small amount of undecomposed lime is fully decomposed in the insulation process of the temperature zone, to ensure that the lime is completely burned through.

The burned lime enters the cooling. When the chamber is cooled, the high air volume is used to improve the active degree of the lime, and cool as much as is needed every hour.

 Lime kiln ash-producing system

The ash of lime kiln adopts four points of disc ash machine. The ash output is determined according to the process regulations of the production line, that is, the ash output is determined according to the yield per unit area of the lime kiln. When the disk ash out machine starts the continuous ash out for a long time (stop only when the ash is sent to the lime bin), or reaches the specified ash out time, the microcomputer automatically issues the order to stop the disk ash out machine, stop the disk ash out machine. After the intermediate ash storage bin, the control system will immediately act to close the electric gate, stop the special lime hoist and end the ash out process.

15. Lime kiln operation and control system

1. Grey control

Lime kiln operation control system has automatic control and manual control.

2. Dadding control

Each kiln shall set the number of feeding per hour according to the unit yield of the lime kiln. The microcomputer sends instructions to the control system to control the action of the system, which is automatically completed according to the prepared feeding and lifting procedures. If the automatic operation fails, it will also be changed to semi-automatic manual operation.

3, kiln temperature intelligent control

Setting the temperature fluctuation range of the kiln calcination, if the actual setting kiln temperature exceeds the PWM limit, the computer shall control the PWM time to ensure temperature stability so that the actual kiln temperature is consistent with the set kiln temperature, stabilizing the kiln calcination and the product quality.

4. Data archiving system

The production data and operation process of the kiln will be located will be automatically archived by the industrial control computer to automatically generate production reports.

sixteen,

1. The lime kiln system is simple to operate, with only 2 people per shift, 3 people per shift, low labor intensity and good working environment; the lime kiln system has low operating cost, stable product quality and reliable work.

2. The structure layout of the lime kiln is compact and reasonable, and it covers a small area.