CN113831768A

CN113831768A - Anti-scaling coating for dry dedusting evaporative cooler

Info

Publication number: CN113831768A
Application number: CN202111124015.5A
Authority: CN
Inventors: 种振宇; 曹玉峰; 李志峰; 崔金强; 杨洪超; 杨光义; 王长宝
Original assignee: Shandong Iron and Steel Co Ltd
Current assignee: Shandong Iron and Steel Co Ltd
Priority date: 2021-09-24
Filing date: 2021-09-24
Publication date: 2021-12-24
Anticipated expiration: 2041-09-24
Also published as: CN113831768B

Abstract

The invention belongs to the technical field of metallurgy, and particularly relates to an anti-scaling coating for a dry dedusting evaporative cooler. The coating is prepared from the following raw materials: nickel, chromium carbide, borax, silicon carbide, titanium dioxide and manganese dioxide. The anti-scaling coating is designed according to the operation characteristics of the dry dedusting evaporative cooler, can be suitable for the high-temperature environment of 800 ℃, has excellent wear resistance, ductility and corrosion resistance, and can effectively avoid scaling of the evaporative cooler.

Description

Anti-scaling coating for dry dedusting evaporative cooler

Technical Field

The invention belongs to the technical field of metallurgy, and particularly relates to an anti-scaling coating for a dry dedusting evaporative cooler.

Background

Converter steelmaking is the most important steelmaking method, and the flue gas purification technology is rapidly developed, wherein the converter dry dedusting technology is widely applied due to good economic benefit and environmental benefit. The converter gas with high heat value can be recovered by adopting the converter dry dedusting technology to process the flue gas, and the recovery amount of per ton of steel gas can reach 100Nm³Meanwhile, the dust concentration of the smoke at the outlet can reach 10mg/Nm³The following.

However, in the actual production process, the dry dedusting system still has some problems to be solved. In the production process of the converter, the dusty high-temperature flue gas flows out from the converter mouth of the converter, enters the vaporization flue, flows through the tail end of the tail flue and enters the evaporation cooler, and the flue gas is cooled by adopting a water spray cooling mode. A part of atomized water drops sprayed by a spray gun nozzle in the evaporative cooler is directly evaporated in the twinkling of an eye in high-temperature flue gas, a part of atomized water drops is evaporated while colliding and adhering with a large amount of high-temperature dust particles contained in the flue gas of the converter, a small amount of atomized water drops are also evaporated while the atomized water drops are adhered to the inner wall of the evaporative cooler along with the collision of the dust particles in the flue gas and water vapor due to poor atomizing effect of the nozzle, the atomized water drops are adhered to the inner wall of the evaporative cooler to form water-containing dust particles, and the scaling phenomenon is caused.

Because the interior of the dry dedusting evaporative cooler is in a high-temperature environment with the temperature as high as 800 ℃, the existing anti-scaling coating is difficult to be applied to the high-temperature environment, and therefore an anti-scaling coating which aims at the operation characteristics of the dry dedusting evaporative cooler and is suitable for the high-temperature environment is urgently needed.

Disclosure of Invention

The invention aims to provide an anti-scaling coating for a dry dedusting evaporative cooler, aiming at the problem that the surface of the dry dedusting evaporative cooler is seriously scaled in the operation process so as to influence the production, the anti-scaling coating is designed according to the operation characteristics of the dry dedusting evaporative cooler, can be suitable for the high-temperature environment of 800 ℃, has excellent wear resistance, ductility and corrosion resistance, and can effectively avoid scaling of the evaporative cooler.

The technical scheme of the invention is as follows: an anti-scaling coating for a dry dedusting evaporative cooler is prepared from the following raw materials: nickel, chromium carbide, borax, silicon carbide, titanium dioxide and manganese dioxide.

The raw materials are calculated according to the following weight percentage:

the raw materials are calculated according to the following weight percentage: 50% of nickel, 40% of chromium carbide, 6% of borax, 1.5% of silicon carbide, 1% of titanium dioxide and 1.5% of manganese dioxide.

The particle sizes of the nickel, the chromium carbide, the borax, the silicon carbide, the titanium dioxide and the manganese dioxide are all-200 meshes. If the particle size is large, the dispersion is not uniform, and the anti-scaling effect is affected.

The anti-scaling paint is applicable at a temperature as high as 800 ℃.

The preparation method of the anti-scaling paint comprises the steps of uniformly mixing the raw materials of nickel, chromium carbide, borax, silicon carbide, titanium dioxide and manganese dioxide according to a proportion, and then extruding and forming the mixture into filaments.

The method for removing the scales of the evaporative cooler by adopting the coating dry-proof method is characterized in that the coating is uniformly sprayed on the inner wall of the pipeline of the evaporative cooler in an electric arc spraying mode.

The invention has the beneficial effects that: the anti-scaling coating for the dry dedusting evaporative cooler mainly comprises Ni, Cr and B elements, specifically nickel, chromium carbide, borax, silicon carbide, titanium dioxide and manganese dioxide. Wherein

Nickel: the comprehensive performance of a coating formed by the coating is improved;

and (3) chromium carbide: high-temperature corrosion is dealt with;

borax: improving the microstructure, high-temperature oxidation behavior and microhardness of the NiCr-based coating by adding the element B;

silicon carbide: the wear resistance of the coating is improved;

titanium dioxide: the function of a dispersant is achieved;

manganese dioxide: for preventing the formed coating from falling off during thermal shock.

The coating is uniformly sprayed on the inner wall of the pipeline of the evaporative cooler in an electric arc spraying mode to form a spraying layer, when water-containing dust particles impact the inner wall of the evaporative cooler along with flue gas flow, the adhesive molecular force between the spraying layer and the dust particles is greatly weakened compared with the adhesive molecular force between the inner wall of the evaporative cooler and the dust particles, and according to the fact that one layer of scale is generated in each furnace, a plurality of layers of ash scales can be generated on the inner wall of the evaporative cooler. Continuous many stove production, then the temperature of evaporative cooler inner wall will take place periodic variation, and then the ash layer that forms can take place inhomogeneous expend with heat and contract with cold and break, and then drop to the curved interior of banana, realize spraying layer "do not glue the ash" target to avoid dry process dust removal evaporative cooler inner wall scale deposit.

The anti-scaling coating has the following advantages:

1. the method is suitable for the working environment of the evaporative cooler at the temperature of more than 400 ℃, and the temperature can reach 800 ℃.

2. The wear resistance is high: with Cr₃C₂And the mixed phase of the product generated in the spraying process is used as hard particles and becomes a framework in the coating structure, and the abrasion resistance requirement can be completely met by the impact of the erosion particles.

3. High ductility: the transition of NiCrB as a carrier ensures the ductility of the entire coating without cracking during temperature changes.

4. The corrosion resistance is high: the NiCrB has good corrosion resistance, and ensures that the hard particles cannot lose efficacy and fall off due to corrosion of the carrier, thereby directly influencing the wear resistance of the coating.

In conclusion, the anti-scaling coating has the advantages of simple formula, obvious effect, low cost and simple use method, and can effectively avoid scaling of the inner wall of the evaporative cooler.

Detailed Description

Example 1

The anti-scaling coating for the dry dedusting evaporative cooler is prepared from the following raw materials in percentage by weight: 47% of nickel; 40% of chromium carbide; 9 percent of borax; 1% of silicon carbide; 1% of titanium dioxide; 2% of manganese dioxide.

Example 2

The anti-scaling coating for the dry dedusting evaporative cooler is prepared from the following raw materials in percentage by weight: 50% of nickel; 38% of chromium carbide; 8 percent of borax; 2% of silicon carbide; 0.5 percent of titanium dioxide; 1.5 percent of manganese dioxide.

Example 3

The anti-scaling coating for the dry dedusting evaporative cooler is prepared from the following raw materials in percentage by weight: 50% of nickel; 40% of chromium carbide; 6 percent of borax; 1.5 percent of silicon carbide; 1% of titanium dioxide; 1.5 percent of manganese dioxide.

Example 4

The anti-scaling coating for the dry dedusting evaporative cooler is prepared from the following raw materials in percentage by weight: 53% of nickel; 35% of chromium carbide; 8 percent of borax; 2% of silicon carbide; 1% of titanium dioxide; 1% of manganese dioxide.

Experimental example 1

Firstly, the purpose of experiment is as follows: the anti-fouling coatings obtained in examples 1 to 4 were tested for wear resistance for 3Cr13 and 20g steel, respectively.

II, experimental materials: the materials were weighed and mixed uniformly according to the formulations described in examples 1-4, respectively, and then extruded into filaments.

Thirdly, experimental steps: the base material of the test piece is 3Cr13 and 20g steel respectively, and the shape is 57 × 25 × 5 mm. After the surface is treated by sand blasting, a coating with the thickness of 1.5mm is sprayed. The wear resistance of a material is measured by the weight loss of wear. Before and after the experiment, a test piece is placed into a beaker filled with an acetone solution, is cleaned in an ultrasonic cleaning instrument for 3-5 minutes, is dried and then is weighed by an electronic balance with the precision of 0.1mg, and is then placed into an abrasion tester, the test piece is pre-ground for 1000 revolutions and then is formally ground for 1000 revolutions, the weight difference of the test piece before and after abrasion is calculated, namely the weight loss, three test pieces are measured by each formula, and the abrasion resistance of the formula is measured by taking the average value.

Fourthly, experimental results and analysis: please refer to Table 1.

Table 1: wear resistance multiple of 3Cr13 and 20g steel

	Example 1	Example 2	Example 3	Example 4
					3Cr13	18	20	21	19
20g	24	28	29	26

As can be seen from the analysis of Table 1, the improvement of the wear-resisting times can effectively avoid the rapid wear of the coating caused by the dust scouring in the flue gas.

Experimental example 2

Firstly, the purpose of experiment is as follows: the anti-fouling coatings obtained in examples 1 to 4 were each tested for their anti-fouling effect.

Thirdly, experimental steps: respectively and uniformly spraying the coating on the inner wall of the evaporative cooler pipeline in an electric arc spraying manner, and comparing the scaling condition of the inner wall of the evaporative cooler pipeline without anti-scaling treatment.

Fourthly, experimental results and analysis: please refer to Table 2.

Table 2: scaling of inner wall of evaporative cooler pipeline after 1 month of use

As can be seen from Table 2, after the anti-scaling treatment is carried out, the inner wall of the evaporative cooler is scaled by less than 20mm after the anti-scaling treatment is used for 1 month, and ash removal is not needed. The inner wall of the evaporative cooler which is not subjected to anti-scaling treatment is scaled by 200-250 mm, and ash removal treatment needs to be carried out in time so as not to influence normal production.

Claims

1. An anti-scaling coating for a dry dedusting evaporative cooler is characterized by being prepared from the following raw materials: nickel, chromium carbide, borax, silicon carbide, titanium dioxide and manganese dioxide.

2. The anti-scaling coating material for the dry dedusting evaporative cooler as set forth in claim 1, wherein the raw materials are in the following weight percentage:

3. the anti-scaling coating material for the dry dedusting evaporative cooler as set forth in claim 2, wherein the raw materials are in the following weight percentage: 50% of nickel, 40% of chromium carbide, 6% of borax, 1.5% of silicon carbide, 1% of titanium dioxide and 1.5% of manganese dioxide.

4. The anti-fouling coating material for a dry dedusting evaporative cooler as set forth in any one of claims 1 to 3, wherein the particle sizes of the nickel, the chromium carbide, the borax, the silicon carbide, the titanium dioxide and the manganese dioxide are all-200 mesh.

5. The anti-scaling coating material for dry dedusting evaporative coolers as recited in any one of claims 1-3, wherein the anti-scaling coating material is suitable for use at temperatures up to 800 ℃.

6. A preparation method of the anti-scaling paint as claimed in claim 1, characterized in that the raw materials of nickel, chromium carbide, borax, silicon carbide, titanium dioxide and manganese dioxide are uniformly mixed according to a proportion and then extruded into filaments.

7. The method for preventing the scale formation of the evaporative cooler by the dry-method dedusting of the coating according to claim 1, wherein the coating is uniformly sprayed on the inner wall of the pipeline of the evaporative cooler by an electric arc spraying method.