CN110986576B

CN110986576B - Energy-saving lining of cement firing system

Info

Publication number: CN110986576B
Application number: CN201911236473.0A
Authority: CN
Inventors: 徐金福; 仝超; 章武英; 陈援兵
Original assignee: Anhui Wuhu Conch Construction and Installation Co Ltd
Current assignee: Anhui Wuhu Conch Construction and Installation Co Ltd
Priority date: 2019-12-05
Filing date: 2019-12-05
Publication date: 2021-12-10
Anticipated expiration: 2039-12-05
Also published as: CN110986576A

Abstract

The invention discloses an energy-saving lining of a cement burning system, which comprises a fire-resistant layer and a heat-insulating layer, wherein the fire-resistant layer is attached to the inner wall of a cylinder body of each component of the cement burning system, and the heat-insulating layer is coated on the surface of the fire-resistant layer; the heat insulation layer contains hollow ceramic microspheres, tin dioxide, bismuth oxide, silicate, aluminum oxide, silicon carbide and chromium oxide; the refractory layer of the rotary kiln sequentially comprises a kiln opening castable, a magnesium spinel brick, a magnesium hercynite, a magnesium aluminate spinel brick, a low-heat-conduction anti-stripping brick DDR-50, a low-heat-conduction anti-stripping brick DDR-30 and a kiln tail castable from a kiln opening to a kiln tail. The energy-saving lining of the cement burning system can reduce the surface heat dissipation of the system, thereby achieving the effects of saving coal consumption and power consumption and reducing the emission of carbon dioxide.

Description

Energy-saving lining of cement firing system

Technical Field

The invention relates to a cement burning system, in particular to an energy-saving lining of the cement burning system.

Background

The cement burning system comprises a preheater, a decomposing furnace, a tertiary air pipe, a grate cooler, a kiln head cover, a rotary kiln and the like. At present, on immobile equipment such as a preheater, a tertiary air duct, a kiln head cover, a decomposing furnace, a kiln tail smoke chamber and the like, the heat degree is relatively high, and the existing lining is of a double-layer structure of heat insulation materials and refractory materials.

The heat insulation material is a calcium silicate board, the secondary air temperature is increased along with the application of the grate cooler of the fourth generation, and the calcium silicate board has heat insulation effect which can not save energy and meet the requirements of environmental protection. Secondly, the strength of the calcium silicate board is low, and when cracks appear on the refractory material lining, the calcium silicate board is easily hollowed by high-speed airflow, so that the refractory material falls off. Thirdly, because the strength of the calcium silicate board is low, the calcium silicate board can not be applied to the heat insulation in the rotary kiln. The heat dissipation problem of the rotary kiln is very serious, and the surface of the cylinder of the rotary kiln can reach more than 350 ℃. The refractory materials of the rotary kiln mainly comprise magnesium refractory bricks and anti-stripping high-alumina bricks, but the rotary kiln has the following problems that the magnesium-aluminum spinel bricks have larger heat conduction systems, so that the surface temperature of a cylinder is higher, the equipment is adversely affected, the heat loss is increased, the anti-stripping high-alumina bricks have the problems in two aspects except the two aspects, and the service life is shorter than two years.

Disclosure of Invention

The invention aims to provide an energy-saving lining of a cement firing system, which can reduce the surface heat dissipation of the system, thereby achieving the effects of saving coal consumption and power consumption and reducing the emission of carbon dioxide.

In order to achieve the purpose, the invention provides a cement burning system energy-saving lining which comprises a fire-resistant layer and a heat-insulating layer, wherein the fire-resistant layer is attached to the inner wall of a cylinder body of each component of the cement burning system, and the heat-insulating layer is coated on the surface of the fire-resistant layer; the heat insulation layer contains hollow ceramic microspheres, tin dioxide, bismuth oxide, silicate, aluminum oxide, silicon carbide and chromium oxide; the refractory layer of the rotary kiln sequentially comprises a kiln opening castable, a magnesium spinel brick, a magnesium hercynite, a magnesium aluminate spinel brick, a low-heat-conduction anti-stripping brick DDR-50, a low-heat-conduction anti-stripping brick DDR-30 and a kiln tail castable from a kiln opening to a kiln tail.

Preferably, the heat insulation layer is formed by coating heat insulation paint on the fire-resistant layer, drying and calcining; the heat-insulating coating contains water-based acrylic emulsion, a defoaming agent, a leveling agent, hollow ceramic microspheres, tin dioxide, bismuth oxide, silicate, aluminum oxide, silicon carbide and chromium oxide.

Preferably, the weight ratio of the water-based acrylic emulsion to the defoaming agent to the leveling agent to the hollow ceramic microspheres to the tin dioxide to the bismuth oxide to the silicate to the aluminum oxide to the silicon carbide to the chromium oxide is 50: 1-3: 1.5-2: 4-6: 3-9: 0.8-1.2: 1.6-2.5: 5-9: 4-8: 0.4-0.9.

Preferably, the defoaming agent is selected from at least one of silicone emulsion, polyoxyethylene polyoxypropylene pentaerythritol ether, polyoxyethylene polyoxypropylene amine ether, polyoxypropylene glycerol ether and polyoxypropylene polyoxyethylene glycerol ether, and polydimethylsiloxane.

Preferably, the leveling agent is selected from at least one of polyacrylic acid, carboxymethyl cellulose, and methyl cellulose.

Preferably, the hollow ceramic microbeads have an average particle size of 20-40nm and the average particle sizes of tin dioxide, bismuth oxide, silicate, aluminum oxide, silicon carbide and chromium oxide are each independently 0.1-0.2 mm.

Preferably, the total length of the cement rotary kiln is 74m, and the refractory layers sequentially comprise 0-0.8m kiln mouth castable, 0.8-2.8m magnesium spinel brick, 2.8-27m magnesium hercynite, 27-38m magnesium aluminate spinel brick, 38-45m low-heat-conduction anti-stripping brick DDR-50, 45-73m low-heat-conduction anti-stripping brick DDR-30 and 73-74m kiln tail castable from the kiln mouth to the kiln tail.

Preferably, the thermal conductivity of the thermal insulation layer is 0.013W/m.k or less.

Preferably, each part of the cement firing system comprises a preheater, a decomposing furnace, a kiln head cover, a tertiary air pipe, a grate cooler and a rotary kiln.

In the technical scheme, the heat insulation layer used by the invention can be directly used for long-time barbecue facing flame, has better heat insulation effect, and has the heat conductivity coefficient of only below 0.013W/m.k; the heat insulation effect is obvious, and the inhibition efficiency can reach about 90% under the condition of a certain thickness. The whole structure of the heat insulation layer is equivalent to the heat insulation mechanism of a thermos bottle, air in the hollow ceramic microsphere cavity added in the material is heated at high temperature, no heat convection is generated, a three-dimensional air layer also exists among the closely arranged hollow ceramic microspheres, and the generation of the heat convection is also avoided; the added heat reflection materials (tin dioxide, bismuth oxide, silicate, aluminum oxide, silicon carbide and chromium oxide) are added as auxiliary fillers, so that the heat conductivity coefficient of the coating is close to the vacuum heat conductivity coefficient, effective heat insulation and heat preservation are achieved, inorganic film-forming substances (calcium silicate boards) with relatively low heat conductivity coefficients are used as heat insulation layers, and a heat insulation shielding layer with a static air layer and the inorganic film-forming substances is constructed together. Under the condition of the original material thickness of 1/3, the temperature of the equipment shell can be reduced by about 50 ℃. The rotary kiln adopts the light heat-insulating bricks to replace the traditional alkaline bricks and high-alumina bricks, and can further improve the heat-insulating and heat-preserving effects.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Detailed Description

The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

In the present invention, unless otherwise specified, directional words such as "head", "tail", and the like included in a term merely represent the orientation of the term in a conventional use state, or are colloquially known by those skilled in the art, and should not be construed as limiting the term.

The invention provides a cement burning system energy-saving lining which comprises a fire-resistant layer and a heat-insulating layer, wherein the fire-resistant layer is attached to the inner wall of a cylinder body of each component of a cement burning system, and the heat-insulating layer is coated on the surface of the fire-resistant layer; the heat insulation layer contains hollow ceramic microspheres, tin dioxide, bismuth oxide, silicate, aluminum oxide, silicon carbide and chromium oxide; the refractory layer of the rotary kiln sequentially comprises a kiln opening castable, a magnesium spinel brick, a magnesium hercynite, a magnesium aluminate spinel brick, a low-heat-conduction anti-stripping brick DDR-50, a low-heat-conduction anti-stripping brick DDR-30 and a kiln tail castable from a kiln opening to a kiln tail.

The scheme adopts the composite series refractory bricks and the low-heat-conductivity series refractory bricks, so that the temperature of the cylinder can be reduced by 40-50 ℃ (the cylinder is used in the same position and the refractory bricks are used for the same period). The temperature reduction of the cylinder has the following advantages: firstly, the heat loss of the whole kiln is reduced, coal used at the head of the kiln is reduced under the same yield, the excess air coefficient at the tail of the kiln is improved, the calcination of a decomposing furnace is facilitated, and the clinker coal consumption is reduced; and secondly, the temperature of the cylinder body is reduced, the stress of the metal cylinder body on the liner body caused by thermal deformation is reduced, and meanwhile, the reduction of the environmental temperature is beneficial to better operation of a mechanical system (such as between the cylinder body and each belt wheel, between the belt wheel and a supporting wheel and the like).

Through the scheme, the temperature of the shell surface of the preheater, the decomposing furnace, the tertiary air pipe, the kiln head cover, the kiln tail smoke chamber and other immobile equipment and the surface of the rotary kiln cylinder is reduced by more than 50 ℃, the specific effect is shown in table 1, and the coal consumption can be reduced by 746 ten thousand tons per year according to the annual output of clinker in China which is 14 hundred million tons calculated by the table. The reduction of CO is calculated according to 14 hundred million tons of annual clinker output in China₂Discharge 36.68 million tons; the kiln lining is totally made of low-heat-conductivity bricks except for a firing zone, the weight of the kiln lining is reduced by 66.7 tons, the load of the kiln is reduced, and the current is reduced. The kiln current is reduced by about 150A, and the power consumption is reduced by 0.24 Kwh/t.

TABLE 1

In the present invention, the formation process of the thermal insulation layer may be in various manners, but in order to further improve the thermal insulation effect, it is preferable that the thermal insulation layer is formed by coating a thermal insulation coating on the refractory layer, drying, and calcining; the heat-insulating coating contains water-based acrylic emulsion, a defoaming agent, a leveling agent, hollow ceramic microspheres, tin dioxide, bismuth oxide, silicate, aluminum oxide, silicon carbide and chromium oxide.

In the above embodiment, the content of each component of the heat insulating coating material may be selected within a wide range, but in order to further improve the heat insulating effect, it is preferable that the weight ratio of the aqueous acrylic emulsion, the defoaming agent, the leveling agent, the hollow ceramic microspheres, the tin dioxide, the bismuth oxide, the silicate, the aluminum oxide, the silicon carbide, and the chromium oxide is 50: 1-3: 1.5-2: 4-6: 3-9: 0.8-1.2: 1.6-2.5: 5-9: 4-8: 0.4-0.9.

In the above embodiment, the specific kind of the defoaming agent can be selected from a wide range, but in order to further improve the heat insulating effect, it is preferable that the defoaming agent is selected from at least one of silicone emulsion, polyoxyethylene polyoxypropylene pentaerythritol ether, polyoxyethylene polyoxypropylene amine ether, polyoxypropylene glycerol ether and polyoxypropylene polyoxyethylene glycerol ether, and polydimethylsiloxane.

In the above embodiment, the specific kind of the leveling agent may be selected within a wide range, but in order to further improve the heat insulating effect, it is preferable that the leveling agent is selected from at least one of polyacrylic acid, carboxymethyl cellulose, and methyl cellulose.

In the above embodiment, the particle diameter of each material may be selected within a wide range, but in order to further improve the heat insulating effect, it is preferable that the average particle diameter of the hollow ceramic micro beads is 20 to 40nm, and the average particle diameters of tin dioxide, bismuth oxide, silicate, alumina, silicon carbide and chromium oxide are each independently 0.1 to 0.2 mm.

In the present invention, the arrangement of the type of the refractory material in the rotary cement kiln can be selected in a wide range, but in order to further improve the heat insulation effect in the rotary cement kiln, it is preferable that the total length of the rotary cement kiln is 74m, and the refractory layers are sequentially made of 0-0.8m kiln mouth castable, 0.8-2.8m magnesium spinel brick, 2.8-27m magnesium hercynite, 27-38m magnesium aluminate spinel brick, 38-45m low thermal conductivity anti-stripping brick DDR-50, 45-73m low thermal conductivity anti-stripping brick DDR-30 and 73-74m kiln tail castable from the kiln mouth to the kiln tail. The configuration of the phi 4.8X 74m cement rotary kiln light insulating brick is shown in table 2.

TABLE 2

0.8-2.8 m: under the condition of not having thicker kiln coating protection, be applied under the naked condition approximately, frequent superficial kiln coating leads to refractory material's temperature variation great, and mechanical stress and chemical attack make the firebrick life cycle can only reach about 6 months in addition, and the MS2T spinel brick that uses in this application can effectively solve down the too high and influence production problem of transition zone barrel temperature.

25-35 m: the DDRML-80 heat-conducting magnesium-aluminum spinel brick is formed by compounding a working layer and a heat-insulating layer, wherein the working layer has high-temperature performances of corrosion resistance, scouring resistance, thermal shock resistance and the like of the magnesium-aluminum spinel brick, can meet the working condition requirement of a transition zone, ensures the service life, and the heat-insulating layer has a good heat-insulating effect.

35-45 m: using low heat conduction anti-stripping bricks DDR-50; 45-73.2 m: using a low-heat-conduction anti-stripping brick DDR-30; the DDR-50 and DDR-30 bricks have small thermal expansion coefficient, stable volume and good thermal shock resistance, and can reduce the material damage caused by the increase of thermal stress; meanwhile, the material has the advantages of low volume density, low heat conductivity coefficient and excellent alkali resistance,

the total weight of the whole kiln is reduced, for example, the total weight of the original whole kiln with the diameter of 4.8 x 72m is 637.74 tons, the total weight of the existing whole kiln with the refractory bricks is 577.38 tons, and the weight of the whole kiln is reduced by 60.36 tons and is reduced by about 9.5 percent compared with the original configuration. The reduction of the whole kiln configuration can reduce the purchase cost by about 33 ten thousand yuan, and the weight of the kiln system is reduced by the light weight of the materials under the condition of the same feeding amount, so that the load of the kiln is reduced to a certain extent, the current of a kiln main machine is reduced, and the power consumption of the operation of the kiln system is reduced.

In the present invention, the thermal conductivity of the thermal insulation layer can be selected within a wide range, but in order to further improve the thermal insulation effect, the thermal conductivity of the thermal insulation layer is preferably 0.010 to 0.012W/m.k.

In addition, in the present invention, the components of the cement firing system can be selected within a wide range, but in order to further increase the application range of the energy saving lining, it is preferable that the components of the cement firing system include a preheater, a decomposing furnace, a kiln head cover, a tertiary air duct, a grate cooler, and a rotary kiln.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.

Claims

1. The energy-saving lining of the cement burning system is characterized by comprising a fire-resistant layer and a heat-insulating layer, wherein the fire-resistant layer is attached to the inner wall of a cylinder body of each component of the cement burning system, and the heat-insulating layer is coated on the surface of the fire-resistant layer; the heat insulation layer contains hollow ceramic microspheres, tin dioxide, bismuth oxide, silicate, aluminum oxide, silicon carbide and chromium oxide; the refractory layer of the rotary kiln sequentially comprises a kiln opening castable, a magnesium spinel brick, a magnesium hercynite, a magnesium aluminate spinel brick, a low-heat-conduction anti-stripping brick DDR-50, a low-heat-conduction anti-stripping brick DDR-30 and a kiln tail castable from a kiln opening to a kiln tail;

the heat insulation layer is formed by coating heat insulation paint on a fire-resistant layer, drying and calcining; the heat insulation coating contains water-based acrylic emulsion, a defoaming agent, a leveling agent, hollow ceramic microspheres, tin dioxide, bismuth oxide, silicate, aluminum oxide, silicon carbide and chromium oxide; the weight ratio of the water-based acrylic emulsion to the defoaming agent to the leveling agent to the hollow ceramic microspheres to the tin dioxide to the bismuth oxide to the silicate to the aluminum oxide to the silicon carbide to the chromium oxide is 50: 1-3: 1.5-2: 4-6: 3-9: 0.8-1.2: 1.6-2.5: 5-9: 4-8: 0.4-0.9;

the total length of the cement rotary kiln is 74m, and the refractory layers sequentially comprise 0-0.8m kiln mouth castable, 0.8-2.8m magnesium spinel brick, 2.8-27m magnesium hercynite, 27-38m magnesium aluminate spinel brick, 38-45m low-heat-conduction anti-stripping brick DDR-50, 45-73m low-heat-conduction anti-stripping brick DDR-30 and 73-74m kiln tail castable from a kiln mouth to a kiln tail.

2. The energy saving liner for cement firing systems as claimed in claim 1, wherein the defoamer is selected from at least one of silicone emulsion, polyoxyethylene polyoxypropylene pentaerythritol ether, polyoxyethylene polyoxypropylene amine ether, polyoxypropylene glycerol ether and polyoxypropylene polyoxyethylene glycerol ether, polydimethylsiloxane.

3. The energy saving lining of cement firing system as claimed in claim 1, wherein the leveling agent is selected from at least one of polyacrylic acid, carboxymethyl cellulose, methyl cellulose.

4. The energy saving lining of cement firing system as claimed in claim 1, wherein the average particle size of the hollow ceramic micro beads is 20-40nm, and the average particle size of each of the tin dioxide, bismuth oxide, silicate, aluminum oxide, silicon carbide and chromium oxide is independently 0.1-0.2 mm.

5. The energy-saving lining for cement burning system as claimed in claim 1, wherein the thermal conductivity of the thermal insulating layer is 0.013W/m-k or less.

6. The energy-saving lining of cement burning system as claimed in claim 1, wherein each part of the cement burning system comprises a preheater, a decomposing furnace, a kiln head cover, a tertiary air pipe, a grate cooler and a rotary kiln.