CN211445544U - Method for capturing and purifying CO by using external combustion type rotary kiln in cement kiln2And an emission reduction system - Google Patents

Abstract

The utility model relates to a cement kiln utilizes external combustion formula rotary kiln entrapment purification CO₂And the emission reduction system comprises a cement rotary kiln and an external combustion rotary kiln, high-temperature materials preheated by a kiln tail preheater of the cement rotary kiln or an external combustion kiln preheater enter the external combustion rotary kiln, and the external combustion kiln is used in a hot air chamber for three times by the cement kilnThe air is continuously heated by the supplementary fuel in the combustion chamber to form high-temperature hot air for heating, the heated hot air continuously returns to the tertiary air pipe of the cement kiln or returns to the tertiary air pipe of the cement kiln after passing through the preheater of the external combustion kiln, the material is decomposed in the external combustion kiln, and CO generated by the decomposition of the material₂The gas is in the closed external combustion kiln, and the effect is that the material in the external combustion kiln is not contacted with the hot air for heating in the hot air chamber, and the CO generated by decomposition₂High purity and quality of gas, and can be directly purified into liquid CO₂Or solid CO₂(dry ice) product, realizing CO₂The aim of emission reduction is to recycle the high-activity CaO and the waste heat generated by decomposition.

Description

External combustion type cement kilnMethod for capturing and purifying CO in rotary kiln2And an emission reduction system

Technical Field

The utility model relates to a cement kiln, in particular to a cement kiln uses external combustion formula rotary kiln entrapment purification CO₂And an emission reduction system.

Background

With CO₂The emission amount of greenhouse gases is increased sharply, and environmental problems such as global warming and the like become more severe. In 2015, 12 months, 195 countries concluded passing through Paris' agreement. China is a main contracted country of Paris agreement, and in order to achieve the aim of reducing emission of greenhouse gases, 2016 (10) months and the working scheme of controlling emission of greenhouse gases printed by thirteen five in the State institute are put forward to 2020, and the unit produces total CO in domestic₂The emission is reduced by 18 percent compared with that in 2015. Industrial sector greenhouse gas emissions account for 28% of the total global emissions (90% of which are CO)₂) 29% of them are from the cement industry (annual emissions of about 40 hundred million tons) -accounting for about 8% of the global total greenhouse gas emissions. And the cement industry discharges CO₂65% of the total amount of limestone comes from the decomposition of limestone.

The utility model discloses based on inventor's decades engage in cement clinker production technology research and development, cement clinker production management and external combustion formula rotary kiln experiment, research, development experience, will external combustion formula rotary kiln experiment, research, development experience combine together with the cement clinker production line, for realizing that cement clinker production line entrapment purification (reduce discharging) CO₂And emission reduction of SO₂Provides a feasible technical measure.

Disclosure of Invention

The utility model provides a cement kiln utilizes external combustion formula rotary kiln entrapment purification CO₂And an emission reduction system, aiming at the technical characteristics of a novel dry-process cement kiln system and an external combustion type rotary kiln system, the external combustion type rotary kiln system is implemented in the cement kiln system in a matching way, thereby realizing the direct capture and purification of CO generated by the decomposition of limestone in the cement production process₂For realizing CO capture and purification (emission reduction) of a cement clinker production line₂And emission reduction of SO₂Provides feasible technical measures, and the specific technical scheme is thatDry method for capturing and purifying CO in cement kiln₂And an emission reduction system which is an automatic control system and comprises a cement rotary kiln and an external combustion rotary kiln, wherein the cement rotary kiln comprises a kiln tail preheater, a decomposing furnace, a rotary kiln, a tertiary air pipe and a clinker cooler, and the external combustion rotary kiln comprises a material distribution and air locking feeder, an external combustion kiln, a combustion chamber and CO₂Gas separator, CO₂Gas exhaust-heat boiler and CO₂Gas secondary dust collector, CO₂The gas three-stage dust collector, the air locking feeder, the external combustion kiln preheater and the external combustion rotary kiln hot air chamber are characterized in that: the material distributing and air locking feeder of the external combustion type rotary kiln is communicated with the discharge hole of any one of the C1, C2 and C4 stage preheaters of the kiln tail preheater of the cement rotary kiln, the air inlet of the external combustion type rotary kiln preheater of the external combustion type rotary kiln is communicated with the upper air outlet of the hot air chamber of the external combustion type rotary kiln, two ends of a tertiary air pipe are respectively connected with a cement kiln decomposing furnace and a clinker cooler, the air outlet end of the tertiary air pipe is communicated with the hot air chamber of the external combustion type rotary kiln through a combustion chamber 8, and CO of the external combustion type rotary kiln₂Gas separator, CO₂Gas exhaust-heat boiler and CO₂And a discharge port of a CaO collector of the gas secondary dust collector is communicated with an air outlet pipe of a C2-level preheater of a kiln tail preheater of the rotary cement kiln, the decomposing furnace and a kiln tail smoke chamber through a conveying pipeline.

The technical effect of the utility model is that partial materials in the cement kiln are decomposed in the external combustion kiln, and the CO generated by the decomposition of the materials₂In the closed external combustion kiln space, the material is not contacted with high-temperature hot air for heating, and CO is generated₂High purity, and can be directly processed into liquid CO₂Or solid CO₂(dry ice); the generated high-activity CaO is continuously used for cement clinker production or directly sold, and a reliable cement clinker production line is formed for capturing and purifying CO₂And emission reduction of SO₂The technical means of (1).

Drawings

Fig. 1 is a schematic view of the structural connection and flow of the present invention.

Detailed Description

As shown in figure 1, a novel dry-method cement kiln captures purified CO₂And an emission reduction system, which is an automatic control system and comprises cement rotationA kiln and an external combustion rotary kiln, wherein the rotary cement kiln comprises a kiln tail preheater 1 of the cement kiln, a decomposing furnace 2, a rotary kiln 3, a tertiary air pipe 4, a cooler 5, a material-separating air-locking feeder 6, an external combustion rotary kiln 7, a combustion chamber 8, CO₂Gas separator 9, CO₂Gas exhaust-heat boiler 10, CO₂Gas secondary dust collector 11, CO₂The device comprises a gas tertiary dust collector 12, an air locking feeder 13, an external combustion kiln preheater 14 and an external combustion rotary kiln hot air chamber 15, wherein a material distribution air locking feeder 6 of the external combustion rotary kiln is communicated with a discharge hole of any one stage preheater of a kiln tail preheater 1 of the cement rotary kiln, namely C1, C2 and C4, an air inlet of the external combustion kiln preheater 14 of the external combustion rotary kiln is communicated with an air outlet of the external combustion rotary kiln hot air chamber 15, two ends of a tertiary air pipe are respectively connected with a cement kiln decomposing furnace (2) and a clinker cooler (5), an air inlet end and an air outlet end of the tertiary air pipe 4 are communicated with the external combustion rotary kiln hot air chamber through a combustion chamber 8, and a CO combustion type rotary kiln of the external₂Gas separator 9, CO₂Gas exhaust-heat boiler 10, CO₂And a discharge port of a CaO collector of the gas secondary dust collector 11 is communicated with a C1, a C2 stage preheater, the decomposing furnace 2 and a kiln tail smoke chamber of a kiln tail preheater 1 of the rotary cement kiln through a conveying pipeline.

The realization method comprises waste heat recovery and CO₂Gas trapping and purifying, high-activity CaO recycling,

the recovery of the waste heat and the scattered heat,

firstly, preheating materials to 800 ℃ in a kiln tail preheater 1 of a cement rotary kiln, burning and decomposing the materials in a decomposing furnace 2 at the temperature of 750 ℃, calcining the generated materials in a rotary kiln 3, and discharging decomposed waste mixture;

secondly, air enters the decomposing furnace 2 through the tertiary air pipe 4 to be used as combustion-supporting air of the decomposing furnace, or is sent into a combustion chamber 8 of the external combustion type rotary kiln through the tertiary air pipe 4, and pulverized coal is continuously added for combustion to generate high-temperature hot air with the temperature of 1100 ℃;

thirdly, high-temperature air is sent into a hot air chamber 15 of the external combustion type rotary kiln to be used as a heat source of the external combustion kiln 7, heat is transferred into the kiln to promote the decomposition of materials in the kiln, the high-temperature air is discharged to 900 ℃, and when a C4-grade material distribution air locking feeder 6 of a kiln tail preheater 1 of the rotary cement kiln is closed, the high-temperature air is sent to an external combustion kiln preheater 14 from an upper outlet of the external combustion kiln 7 to preheat raw materials from a kiln tail preheater 1C 1-grade of the rotary cement kiln, or the high-temperature air returns to a tertiary air duct and then enters a cement kiln decomposing furnace 2;

waste rock and CO₂The gas is collected and purified, and then the gas is purified,

fourthly, part of the materials preheated to 700 ℃ from the kiln tail preheater 1 enter an external combustion type rotary kiln 7 for heating and decomposition,

most of the decomposed materials in the external combustion kiln 7 are discharged from the kiln head, and part of fine powder and CO are discharged from the kiln head₂Gas admission to CO₂The CO is separated by a gas separator 9₂Gas passing through CO₂Cooling the gas exhaust-heat boiler 10, and introducing CO₂Gas secondary dust collector 11, CO₂Carrying out purification by using a gas third-stage dust collector 12, carrying out heavy planting until the purification degree reaches that the dust content is less than or equal to 5mg/m, and carrying out treatment by using the next system;

the method comprises the steps of recycling high-activity CaO,

⑤, and part of fine powder discharged from the kiln head of the external combustion kiln 7 is the first high-activity CaO and self-CO₂The second kind of fine powder discharged from the gas secondary dust collector 11 is high-activity CaO and self-CO₂The third high-activity CaO of the fine powder discharged by the gas three-level dust collector 12 is respectively conveyed to a C1 level raw material feeding pipe of a cement kiln tail preheater 1 through pneumatic transmission according to requirements to be used as a desulfurizer to reduce SO of a cement kiln system₂Discharging, and simultaneously continuously producing cement clinker; or sent to the cement kiln decomposing furnace 2 to continue producing cement clinker; or sent to the tail smoke chamber of the cement kiln to continue producing cement clinker or sold.

The embodiments of the present invention should not be construed as limiting the scope of the present invention, and any modifications, equivalent replacements, and improvements that can be made by a person skilled in the art within the spirit and principle of the present invention are also included in the protection scope of the present invention.

Claims (1)

1. Method for capturing and purifying CO by using external combustion type rotary kiln in cement kiln₂And an emission reduction system which is an automatic control system and comprises a rotary cement kiln and an external combustion rotary kiln, wherein the rotary cement kiln comprises a kiln tail preheater (1) and a decomposition deviceA furnace (2), a rotary kiln (3), a tertiary air pipe (4) and a clinker cooler (5), wherein the external combustion type rotary kiln comprises a material distribution air locking feeder (6), an external combustion kiln (7), a combustion chamber (8) and CO₂Gas separator (9), CO₂Gas exhaust-heat boiler (10), CO₂Gas secondary dust collector (11), CO₂Tertiary dust collector of gas (12), lock wind feeder (13), outer kiln preheater (14), outer burning formula rotary kiln hot-blast chamber (15), its characterized in that: the material distributing and air locking feeder (6) of the external combustion type rotary kiln is communicated with the discharge hole of any one of the C1, C2 and C4 grade preheaters of the kiln tail preheater (1) of the cement rotary kiln, the air inlet of the external combustion kiln preheater (14) of the external combustion type rotary kiln is communicated with the upper air outlet of the hot air chamber (15) of the external combustion type rotary kiln, the two ends of a tertiary air pipe are respectively connected with a cement kiln decomposing furnace (2) and a clinker cooler (5), the air inlet and outlet ends of the tertiary air pipe (4) are communicated with the hot air chamber of the external combustion type rotary kiln through a combustion chamber (8), and the CO of the external combustion type rotary kiln₂Gas separator (9), CO₂Gas exhaust-heat boiler (10), CO₂The discharge hole of the CaO collector of the gas secondary dust collector (11) is communicated with the air outlet pipe of the C2-level preheater of the kiln tail preheater (1) of the rotary cement kiln, the decomposing furnace (2) and the kiln tail smoke chamber through a conveying pipeline.

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