Energy-saving system combining dead-burnt magnesium oxide and light-burnt magnesium oxide

Abstract

The utility model discloses an energy-saving system combining dead burning and light burning of magnesium oxide, which comprises a light burning magnesium oxide unit, the light burning magnesium oxide unit comprises a suspension preheater, an out-of-kiln predecomposition furnace and a suspension cooler, a top outlet of the out-of-kiln predecomposition furnace is connected with an inlet of the suspension preheater, and a top outlet of the out-of-kiln predecomposition furnace is connected with an outlet of the suspension cooler. A bottom outlet of the out-kiln predecomposition furnace is connected with an outlet air pipe of the suspension cooler, and a blanking pipe of the suspension preheater is connected with an inlet of the suspension cooler; the magnesium oxide dead burning unit comprises a rotary kiln and a grate cooler, a branch pipe is arranged on the pre-decomposition furnace outside the kiln and connected with the rotary kiln, and an outlet of the rotary kiln is connected with an inlet of the grate cooler. The device disclosed by the utility model can be used for independently preparing the light calcined magnesia and simultaneously preparing the light calcined magnesia and the dead calcined magnesia, the two processes can be switched and selected as required, and the device has the characteristics of low energy consumption, low emission, high efficiency and the like.

Description

Technical Field

[0001] The utility model relates to an energy-saving system combining heavy-burned and light-burned magnesium oxide. Background Art

[0002] The Chinese patent document with publication number CN107265890A discloses a complete set of equipment and method for producing a magnesite light-burned magnesia and dead-burned magnesia production line, including a grinding device, a light-burning device and a dead-burning device. The complete set of equipment uses magnesite as raw material, and successively preheats, suspends and calcines the material, and cools it, so that light-burned magnesia and dead-burned magnesia can be prepared simultaneously. However, the device cannot complete the preparation of light-burned magnesia alone, and the heat of the light-burned magnesia in the suspension cooler is not utilized.

[0003] In view of this, the utility model provides an energy-saving process system combining new heavy-burned and light-burned magnesium oxide based on a suspension preheater, an off-kiln precalciner, a suspension cooler, a rotary kiln, and a grate cooler to solve the backward production process problems of domestic light-burned magnesium oxide and heavy-burned magnesium oxide production enterprises. When light-burned magnesium oxide and heavy-burned magnesium oxide are prepared at the same time, the waste heat of the rotary kiln and the grate cooler is further utilized; when light-burned magnesium oxide is prepared alone, the waste heat of the suspension cooler is further utilized to reduce energy consumption and improve thermal efficiency. Summary of the invention

[0004] The utility model provides an energy-saving system combining heavy-burned and light-burned magnesium oxide in order to solve the problems existing in the prior art.

[0005] The technical solutions adopted in this utility model are:

[0006] An energy-saving system combining heavy-burned and light-burned magnesium oxide, comprising:

[0007] A light-burned magnesium oxide unit, the light-burned magnesium oxide unit comprising a suspension preheater, an off-kiln precalciner and a suspension cooler, the top outlet of the off-kiln precalciner is connected to the inlet of the suspension preheater, the bottom outlet of the off-kiln precalciner is connected to the outlet air duct of the suspension cooler, and the feed pipe of the suspension preheater is connected to the inlet of the suspension cooler;

[0008] The dead-burned magnesium oxide unit comprises a rotary kiln and a grate cooler. A branch pipe is arranged on the pre-decomposition furnace outside the kiln to connect with the rotary kiln, and the outlet of the rotary kiln is connected with the inlet of the grate cooler.

[0009] Furthermore, the suspension preheater comprises a first-stage preheating cyclone, a second-stage preheating cyclone, a third-stage preheating cyclone, a fourth-stage preheating cyclone and a fifth-stage preheating cyclone, the discharge pipe of the first-stage preheating cyclone is connected to the inlet of the second-stage preheating cyclone, the discharge pipe of the second-stage preheating cyclone is connected to the inlet of the third-stage preheating cyclone, the discharge pipe of the third-stage preheating cyclone is connected to the inlet of the fourth-stage preheating cyclone, a dividing valve is provided on the discharge pipe of the fourth-stage waste heat cyclone, and is respectively connected to the middle and lower parts of the pre-decomposition furnace outside the kiln through the dividing valve, and the top outlet of the pre-decomposition furnace outside the kiln is connected to the inlet of the fifth-stage preheating cyclone.

[0010] Furthermore, the air outlet of the fifth-stage preheating cyclone is connected to the inlet of the fourth-stage preheating cyclone, the air outlet of the fourth-stage preheating cyclone is connected to the inlet of the third-stage preheating cyclone, the air outlet of the third-stage preheating cyclone is connected to the inlet of the second-stage preheating cyclone, and the air outlet of the second-stage preheating cyclone is connected to the inlet of the first-stage preheating cyclone.

[0011] Furthermore, the suspension cooler includes a first-stage cooling cyclone, a second-stage cooling cyclone and a third-stage cooling cyclone. The bottom outlet of the pre-decomposition furnace outside the kiln is connected to the outlet air duct of the first-stage cooling cyclone, and a second gate valve is arranged between the two. The discharge pipe of the first-stage cooling cyclone is connected to the inlet of the second-stage cooling cyclone, and the discharge pipe of the second-stage cooling cyclone is connected to the inlet of the third-stage cooling cyclone.

[0012] Furthermore, a branch pipe and a tertiary air duct are arranged above the second gate valve and connected to the rotary kiln, a fourth gate valve is arranged on the branch pipe, and a third gate valve is arranged on the tertiary air duct.

[0013] Furthermore, a calcining furnace burner is provided on the precalcining furnace outside the kiln.

[0014] Furthermore, the pre-calcining furnace outside the kiln is connected with a first gate valve, and a light-burned magnesium oxide dust collection system is provided downstream of the first gate valve; and a heavy-burned magnesium oxide dust collection system is connected to the grate cooler.

[0015] The utility model also discloses a method for using an energy-saving system combining heavy-burned and light-burned magnesium oxide. When only the light-burned magnesium oxide unit is operated, the first, third and fourth gate valves are closed, and the second gate valve is opened. The magnesite enters the first, second, third and fourth preheating cyclones in sequence for four-stage preheating treatment. The fourth preheating cyclone collects materials and enters a pre-decomposition furnace outside the kiln for calcination through a material dividing valve. The fuel of the burner burns under the action of the lower combustion-supporting wind to provide a heat source for the calcination and decomposition of the magnesite in the pre-decomposition furnace outside the kiln. The magnesite material is calcined to generate light-burned magnesium oxide. The materials collected by the fifth preheating cyclone are cooled and collected in the first cooling cyclone 13, the second cooling cyclone and the third cooling cyclone in sequence, and finally sent to the light-burned magnesium oxide storage and transportation system.

[0016] Cooling air is introduced into the third cooling cyclone. In the process of cooling the light-burned magnesium oxide, the cooling air is heated step by step in the second and first cooling cyclones, and enters the pre-decomposition furnace outside the kiln as combustion-supporting hot air. The flue gas and materials of the pre-decomposition furnace outside the kiln enter the fifth preheating cyclone through the air duct at the top outlet. After gas-solid separation, the materials are collected from the discharge port of the fifth preheating cyclone and enter the cooling cyclone for multi-stage cooling, while the flue gas enters the fourth preheating cyclone from the air outlet of the fifth preheating cyclone as the preheating heat source of the fourth preheating cyclone to preheat the materials collected in the third preheating cyclone. After the gas and materials enter the fourth preheating cyclone for gas-solid separation, the flue gas enters the third preheating cyclone as the third preheating The preheating heat source of the cyclone is used to preheat the materials collected by the second-stage preheating cyclone. After the gas and materials enter the third-stage preheating cyclone for gas-solid separation, the flue gas enters the second-stage preheating cyclone as the preheating heat source for the second-stage preheating cyclone to preheat the materials collected by the first-stage preheating cyclone. After the gas and materials enter the second-stage preheating cyclone for gas-solid separation, the flue gas enters the first-stage preheating cyclone as the preheating heat source for the first-stage preheating cyclone to preheat the materials entering the first-stage preheating cyclone from the magnesite metering and furnace entry system. After the gas and materials enter the first-stage preheating cyclone for gas-solid separation, they enter the environmental protection dust removal system through the air outlet of the first-stage preheating cyclone for flue gas treatment and are finally discharged from the chimney.

[0017] Furthermore, when the light-burned magnesium oxide unit and the heavy-burned magnesium oxide unit are operated simultaneously, the second gate valve is closed, and the first, third and fourth gate valves are opened, and the dolomite enters the first, second, third and fourth preheating cyclones for four-stage preheating treatment, and the material collected by the fourth-stage preheating cyclone enters the precalcining furnace outside the kiln through the dividing valve for calcination, and the fuel of the burner burns under the action of the lower combustion-supporting wind, and the dolomite material is calcined to generate light-burned magnesium oxide, and the material collected by the fifth-stage preheating cyclone is cooled and collected in the first, second and third-stage cooling cyclones in turn, and finally sent to the light-burned magnesium oxide storage and transportation system;

[0018] After being pressed by a briquette machine, the light-burned magnesium oxide is transported to a rotary kiln for the preparation of dead-burned magnesium oxide. The material calcined in the rotary kiln enters a grate cooler for cooling, and the cooled material enters a dead-burned magnesium oxide storage and transportation system;

[0019] As the first gate valve is open and the second gate valve is closed, the flue gas from the first stage cooling cyclone enters the light-burned magnesium oxide dust collection system for flue gas treatment and is finally discharged from the chimney. The flue gas from the rotary kiln and the tertiary air duct provides the lower combustion-supporting air for the precalciner outside the kiln. The combustion-supporting air enters the fifth stage preheating cyclone through the top outlet of the precalciner outside the kiln.

[0020] The flue gas from the rotary kiln and the tertiary air duct enters the pre-decomposition furnace outside the kiln as combustion-supporting hot air. The flue gas and materials from the pre-decomposition furnace outside the kiln enter the fifth-stage preheating cyclone through the air duct at the top outlet. The materials are collected from the discharge port of the fifth-stage preheating cyclone and enter the cooling cyclone for multi-stage cooling.

[0021] The utility model has the following beneficial effects:

[0022] The utility model can complete the preparation of light-burned magnesium oxide alone, and can also meet the simultaneous preparation of light-burned magnesium oxide and dead-burned magnesium oxide. When light-burned magnesium oxide is prepared alone, the waste heat of the suspension cooler is used in the pre-decomposition furnace outside the kiln and the suspension preheating system; when light-burned magnesium oxide and dead-burned magnesium oxide are prepared simultaneously, the waste heat in the grate cooler and the rotary kiln is used in the pre-decomposition furnace outside the kiln and the suspension preheating system, thereby improving the utilization efficiency of thermal energy. The two processes can be switched and selected as needed, and have the characteristics of low energy consumption, low emissions, high efficiency, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the utility model.

[0024] In the figure:

[0025] Suspension preheater: 1. First-stage preheating cyclone; 2. Second-stage preheating cyclone; 3. Third-stage preheating cyclone; 4. Fourth-stage preheating cyclone; 5. Fifth-stage preheating cyclone.

[0026] 6. Precalciner outside the kiln; 7. Dispensing valve; 8. Calciner burner; 9. First gate valve; 10. Second gate valve; 11. Third gate valve; 12. Fourth gate valve;

[0027] Suspension cooler: 13. First-stage cooling cyclone; 14. Second-stage cooling cyclone; 15. Third-stage cooling cyclone.

[0028] 16. Rotary kiln; 17. Grate cooler. DETAILED DESCRIPTION

[0029] The utility model is further described below in conjunction with the accompanying drawings.

[0030] like Figure 1 As shown, the utility model is an energy-saving system combining heavy-burned and light-burned magnesium oxide, which utilizes magnesite to prepare light-burned magnesium oxide and heavy-burned magnesium oxide; the system is divided into a light-burned magnesium oxide unit and a heavy-burned magnesium oxide unit.

[0031] The light-burned magnesium oxide unit includes a suspension preheater, an off-kiln precalcining furnace 6 and a suspension cooler.

[0032] The dead-burned magnesium oxide unit includes a rotary kiln 16 and a grate cooler 17 .

[0033] The suspension preheater includes a first-stage preheating cyclone 1, a second-stage preheating cyclone 2, a third-stage preheating cyclone 3, a fourth-stage preheating cyclone 4, and a fifth-stage preheating cyclone 5.

[0034] The suspension cooler comprises a first-stage cooling cyclone 13 , a second-stage cooling cyclone 14 , and a third-stage cooling cyclone 15 .

[0035] The first-stage preheating cyclone 1 discharge pipe is connected to the inlet of the second-stage preheating cyclone 2, the second-stage preheating cyclone 2 discharge pipe is connected to the inlet of the third-stage preheating cyclone 3, the third-stage preheating cyclone 3 discharge pipe is connected to the inlet of the fourth-stage preheating cyclone 4, the fourth-stage waste heat cyclone 4 discharge pipe is provided with a dividing valve 7, and is respectively connected to the middle and lower parts of the pre-calcining furnace 6 outside the kiln through the dividing valve 7, the top outlet of the pre-calcining furnace 6 outside the kiln is connected to the inlet of the fifth-stage preheating cyclone 5, and the bottom outlet of the pre-calcining furnace 6 outside the kiln is connected to the first-stage cooling cyclone The outlet air duct of the wind tube 13 is connected, and a second gate valve 10 is arranged in between. An air duct is arranged below the second gate valve 10 to connect to the light-burned magnesium oxide dust collection system. A first gate valve 9 is arranged on the air duct. The discharge pipe of the fifth-stage preheating cyclone 5 is connected to the inlet of the first-stage cooling cyclone 13. The discharge pipe of the first-stage cooling cyclone 13 is connected to the inlet of the second-stage cooling cyclone 14. The discharge pipe of the second-stage cooling cyclone 14 is connected to the inlet of the third-stage cooling cyclone 15. The discharge pipe of the third-stage cooling cyclone 15 is connected to the light-burned magnesium oxide storage and transportation system.

[0036] A branch pipe is provided above the second gate valve and connected to the rotary kiln 16, a fourth gate valve 12 is provided on the branch pipe, the tertiary air duct is connected to the cone of the pre-decomposition furnace outside the kiln, a third gate valve 11 is provided on the tertiary air duct, the outlet of the rotary kiln 16 is connected to the inlet of the grate cooler 17, the bottom outlet of the grate cooler 17 is connected to the heavy-burned magnesium oxide storage and transportation system, and the hot air outlet of the grate cooler 17 is connected to the heavy-burned magnesium oxide dust collection system.

[0037] When only the light-burned magnesium oxide unit is in operation, the first gate valve 9, the third gate valve 11, and the fourth gate valve 12 are closed, and the second gate valve 10 is opened. After being dispersed by the magnesite metering and furnace entry system, the magnesite enters the first-stage preheating cyclone 1, the second-stage preheating cyclone 2, the third-stage preheating cyclone 3, and the fourth-stage preheating cyclone 4 in sequence for four-stage preheating treatment. The materials collected by the fourth-stage preheating cyclone 4 enter the middle and lower parts of the precalcining furnace 6 outside the kiln through the dividing valve 7 for calcination, and the distribution ratio of the materials entering the middle and lower parts of the precalcining furnace 6 outside the kiln can be adjusted according to the dividing valve 7. The outer precalciner 6 is provided with an outer precalciner burner 8 at the bottom. The fuel burns under the action of the lower combustion-supporting wind, providing a heat source for the calcination and decomposition of magnesite in the outer precalciner 6. The magnesite material is calcined to generate light-burned magnesium oxide. The calcination temperature of the material in the outer precalciner 6 is about 840-900°C, and the retention time is 6-10s. The material collected by the fifth-stage preheating cyclone 5 is cooled and collected in the first-stage cooling cyclone 13, the second-stage cooling cyclone 14 and the third-stage cooling cyclone 15 in turn. The temperature of the light-burned magnesium oxide can be lower than 120°C after multi-stage cooling, and finally sent to the light-burned magnesium oxide storage and transportation system.

[0038] The air outlet of the third-stage cooling cyclone 15 is connected to the inlet of the second-stage cooling cyclone 14, the air outlet of the second-stage cooling cyclone 14 is connected to the inlet of the first-stage cooling cyclone 13, the air outlet of the first-stage cooling cyclone 13 is connected to the bottom of the pre-decomposition furnace 6 outside the kiln, providing lower combustion-supporting air for the pre-decomposition furnace 6 outside the kiln, and the combustion-supporting air enters the fifth-stage preheating cyclone 5 through the top outlet of the pre-decomposition furnace 6 outside the kiln, the air outlet of the fifth-stage preheating cyclone 5 is connected to the inlet of the fourth-stage preheating cyclone 4, the air outlet of the fourth-stage preheating cyclone 4 is connected to the inlet of the third-stage preheating cyclone 3, the air outlet of the third-stage preheating cyclone 3 is connected to the inlet of the second-stage preheating cyclone 2, and the air outlet of the second-stage preheating cyclone 2 is connected to the inlet of the first-stage preheating cyclone 1.

[0039] The cooling wind introduced into the third-stage cooling cyclone 15 is air. In the process of cooling the light-burned magnesium oxide, the cooling wind is heated step by step in the second and first-stage cooling cyclones, and enters the pre-decomposition furnace 6 outside the kiln as combustion-supporting hot air. The flue gas and materials of the pre-decomposition furnace 6 outside the kiln enter the fifth-stage preheating cyclone 5 through the air duct at the top outlet. After gas-solid separation, the materials are collected from the discharge port of the fifth-stage preheating cyclone 5 and enter the cooling cyclone for multi-stage cooling, while the flue gas enters the fourth-stage preheating cyclone 4 from the air outlet of the fifth-stage preheating cyclone 5 as a preheating heat source for the fourth-stage preheating cyclone 4 to preheat the materials collected in the third-stage preheating cyclone 3. After the gas and materials enter the fourth-stage preheating cyclone 4 for gas-solid separation, the flue gas enters the third-stage preheating cyclone 3 as a preheating heat source for the third-stage preheating cyclone 3. Preheating heat source, preheating the materials collected by the second-stage preheating cyclone 2, after the gas and materials enter the third-stage preheating cyclone 3 for gas-solid separation, the flue gas enters the second-stage preheating cyclone 2, as the preheating heat source of the second-stage preheating cyclone 2, to preheat the materials collected by the first-stage preheating cyclone 1, after the gas and materials enter the second-stage preheating cyclone 2 for gas-solid separation, the flue gas enters the first-stage preheating cyclone 1, as the preheating heat source of the first-stage preheating cyclone 1, to preheat the materials entering the first-stage preheating cyclone 1 from the magnesite metering and furnace entry system, after the gas and materials enter the first-stage preheating cyclone 1 for gas-solid separation, the outlet exhaust gas temperature is below 220°C, and enters the environmental protection dust removal system through the air outlet of the first-stage preheating cyclone 1 for flue gas treatment and finally discharged from the chimney.

[0040] When the light-burned magnesium oxide unit and the heavy-burned magnesium oxide unit are running at the same time, the second gate valve 10 is closed, and the first gate valve 9, the third gate valve 11, and the fourth gate valve 12 are opened. After being dispersed by the magnesite metering and furnace entry system, the magnesite enters the first-stage preheating cyclone 1, the second-stage preheating cyclone 2, the third-stage preheating cyclone 3, and the fourth-stage preheating cyclone 4 in sequence for four-stage preheating treatment. The materials collected by the fourth-stage preheating cyclone 4 enter the middle and lower parts of the pre-calcining furnace 6 outside the kiln through the dividing valve 7 for calcination, and the distribution ratio of the materials entering the middle and lower parts of the pre-calcining furnace 6 outside the kiln can be adjusted according to the dividing valve 7. The outer precalciner 6 is provided with an outer precalciner burner 8 at the bottom. The fuel burns under the action of the lower combustion-supporting wind, providing a heat source for the calcination and decomposition of magnesite in the outer precalciner 6. The magnesite material is calcined to generate light-burned magnesium oxide. The calcination temperature of the material in the outer precalciner 6 is about 840-900°C, and the retention time is 6-10s. The material collected by the fifth-stage preheating cyclone 5 is cooled and collected in the first-stage cooling cyclone 13, the second-stage cooling cyclone 14 and the third-stage cooling cyclone 15 in turn. The temperature of the light-burned magnesium oxide can be lower than 120°C after multi-stage cooling, and finally sent to the light-burned magnesium oxide storage and transportation system.

[0041] After being pressed by a briquette press, the light-burned magnesium oxide is transported to a rotary kiln 16 for preparation of dead-burned magnesium oxide, and the temperature in the rotary kiln 16 is 1800-2000° C. The material calcined in the rotary kiln 16 enters a grate cooler 17 for cooling, and the cooled material enters a dead-burned magnesium oxide storage and transportation system.

[0042] Cooling air is introduced into the inlet of the third-stage cooling cyclone 15, and the air outlet is connected to the inlet of the second-stage cooling cyclone 14, the air outlet of the second-stage cooling cyclone 14 is connected to the inlet of the first-stage cooling cyclone 13, and the air outlet of the first-stage cooling cyclone 13 is connected to the bottom of the pre-decomposition furnace 6 outside the kiln. Since the first gate valve 9 is opened and the second gate valve 10 is closed, the flue gas from the first-stage cooling cyclone enters the light-burned magnesium oxide dust collection system for flue gas treatment and is finally discharged from the chimney. The flue gas from the rotary kiln 16 and the tertiary air duct provides lower combustion-supporting air for the pre-decomposition furnace 6 outside the kiln. The combustion-supporting air enters the fifth-stage preheating cyclone 5 through the top outlet of the pre-decomposition furnace 6 outside the kiln. The air outlet of the fifth-stage preheating cyclone 5 is connected to the inlet of the fourth-stage preheating cyclone 4, the air outlet of the fourth-stage preheating cyclone 4 is connected to the third-stage preheating cyclone 3, the air outlet of the third-stage preheating cyclone 3 is connected to the second-stage preheating cyclone 2, and the air outlet of the second-stage preheating cyclone 2 is connected to the first-stage preheating cyclone 1.

[0043] The cooling wind introduced into the third-stage cooling cyclone 15 is air. In the process of cooling the light-burned magnesium oxide, the cooling wind is heated step by step by the second and first-stage cooling cyclones, and then enters the light-burned magnesium oxide dust collection system for flue gas treatment and is finally discharged from the chimney.

[0044] The flue gas from the rotary kiln 16 and the tertiary air duct enters the preheating furnace 6 outside the kiln as combustion-supporting hot air. The flue gas and materials from the preheating furnace 6 outside the kiln enter the fifth-stage preheating cyclone 5 through the air duct at the top outlet. After gas-solid separation, the materials are collected from the discharge port of the fifth-stage preheating cyclone 5 and enter the cooling cyclone for multi-stage cooling, while the flue gas enters the fourth-stage preheating cyclone 4 from the air outlet of the fifth-stage preheating cyclone 5 as a preheating heat source for the fourth-stage preheating cyclone 4 to preheat the materials collected by the third-stage preheating cyclone 3. After the gas and materials enter the fourth-stage preheating cyclone 4 for gas-solid separation, the flue gas enters the third-stage preheating cyclone 3 as a preheating heat source for the third-stage preheating cyclone 3 to preheat the materials collected by the second-stage preheating cyclone 2. The material is preheated, and the gas and material enter the third-stage preheating cyclone 3 for gas-solid separation. The flue gas enters the second-stage preheating cyclone 2, which serves as the preheating heat source for the second-stage preheating cyclone 2 to preheat the material collected by the first-stage preheating cyclone 1. The gas and material enter the second-stage preheating cyclone 2 for gas-solid separation. The flue gas enters the first-stage preheating cyclone 1, which serves as the preheating heat source for the first-stage preheating cyclone 1 to preheat the material entering the first-stage preheating cyclone 1 from the magnesite metering and furnace entry system. After the gas and material enter the first-stage preheating cyclone 1 for gas-solid separation, the outlet exhaust gas temperature is below 220°C, and enters the environmental protection dust removal system through the air outlet of the first-stage preheating cyclone 1 for flue gas treatment and finally discharged from the chimney.

[0045] The utility model can meet the needs of preparing light-burned magnesium oxide alone, and can also meet the needs of preparing light-burned magnesium oxide and dead-burned magnesium oxide at the same time. When light-burned magnesium oxide is prepared alone, the waste heat of the suspension cooler is used in the pre-decomposition furnace outside the kiln and the suspension preheating system; when light-burned magnesium oxide and dead-burned magnesium oxide are prepared at the same time, the waste heat in the grate cooler and the rotary kiln is used in the pre-decomposition furnace outside the kiln and the suspension preheating system, thereby improving the efficiency of thermal energy utilization. The two processes can be switched and selected as needed, and have the characteristics of low energy consumption, low emissions, high efficiency, etc.

[0046] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements without departing from the principle of the present invention, and these improvements should also be regarded as within the protection scope of the present invention.

Claims

1. An energy-saving system combining heavy-burned and light-burned magnesium oxide, characterized in that: include A light-burned magnesium oxide unit, the light-burned magnesium oxide unit comprising a suspension preheater, an off-kiln precalcining furnace (6) and a suspension cooler, the top outlet of the off-kiln precalcining furnace (6) being connected to the inlet of the suspension preheater, the bottom outlet of the off-kiln precalcining furnace (6) being connected to the outlet air duct of the suspension cooler, and the discharge pipe of the suspension preheater being connected to the inlet of the suspension cooler; A dead-burned magnesium oxide unit comprises a rotary kiln (16) and a grate cooler (17); a branch pipe is provided on a pre-calcining furnace (6) outside the kiln and connected to the rotary kiln (16); and an outlet of the rotary kiln (16) is connected to an inlet of the grate cooler (17).

2. The energy-saving system combining heavy-burned and light-burned magnesium oxide according to claim 1, characterized in that: The suspension preheater comprises a first-stage preheating cyclone (1), a second-stage preheating cyclone (2), a third-stage preheating cyclone (3), a fourth-stage preheating cyclone (4) and a fifth-stage preheating cyclone (5); a discharge pipe of the first-stage preheating cyclone (1) is connected to an inlet of the second-stage preheating cyclone (2); a discharge pipe of the second-stage preheating cyclone (2) is connected to an inlet of the third-stage preheating cyclone (3); a discharge pipe of the third-stage preheating cyclone (3) is connected to an inlet of the fourth-stage preheating cyclone (4); a material distribution valve (7) is provided on the discharge pipe of the fourth-stage preheating cyclone (4) and is respectively connected to a middle part and a lower part of an external preheating furnace (6) through the material distribution valve (7); and a top outlet of the external preheating furnace (6) is connected to an inlet of the fifth-stage preheating cyclone (5).

3. The energy-saving system combining heavy-burned and light-burned magnesium oxide according to claim 2, characterized in that: The air outlet of the fifth-stage preheating cyclone barrel (5) is connected to the inlet of the fourth-stage preheating cyclone barrel (4), the air outlet of the fourth-stage preheating cyclone barrel (4) is connected to the inlet of the third-stage preheating cyclone barrel (3), the air outlet of the third-stage preheating cyclone barrel (3) is connected to the inlet of the second-stage preheating cyclone barrel (2), and the air outlet of the second-stage preheating cyclone barrel (2) is connected to the inlet of the first-stage preheating cyclone barrel (1).

4. The energy-saving system combining heavy-burned and light-burned magnesium oxide according to claim 1, characterized in that: The suspension cooler comprises a first-stage cooling cyclone (13), a second-stage cooling cyclone (14) and a third-stage cooling cyclone (15); the bottom outlet of the pre-calcining furnace (6) outside the kiln is connected to the outlet air duct of the first-stage cooling cyclone (13), and a second gate valve (10) is arranged between the two; the discharge pipe of the first-stage cooling cyclone (13) is connected to the inlet of the second-stage cooling cyclone (14), and the discharge pipe of the second-stage cooling cyclone (14) is connected to the inlet of the third-stage cooling cyclone (15).

5. The energy-saving system combining heavy-burned and light-burned magnesium oxide according to claim 4, characterized in that: A branch pipe and a tertiary air duct are arranged above the second gate valve (10) and connected to the rotary kiln (16); a fourth gate valve (12) is arranged on the branch pipe, and a third gate valve (11) is arranged on the tertiary air duct.

6. The energy-saving system combining heavy-burned and light-burned magnesium oxide according to claim 1, characterized in that: The precalcining furnace (6) outside the kiln is provided with a calcining furnace burner (8).

7. The energy-saving system combining heavy-burned and light-burned magnesium oxide according to claim 1, characterized in that: The precalcining furnace outside the kiln (6) is connected to a first gate valve (9), and a light-burned magnesium oxide dust collection system is provided downstream of the first gate valve (9); and a heavy-burned magnesium oxide dust collection system is connected to the grate cooler (17).

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