Titanium dioxide special drying equipment

project description:
In recent years, my country's titanium dioxide industry has increased several times in terms of production capacity, output and market demand, and my country's titanium dioxide industry has brought about a period of prosperity.
Titanium dioxide is considered to be a white pigment with better performance in the world, and is widely used in coatings, plastics, papermaking, printing, ink, chemical fiber, rubber, cosmetics and other industries. Titanium dioxide is chemically stable and does not react with most substances under normal circumstances. Titanium dioxide has three crystals in nature: platy, anatase and rutile. The paint industry is a larger user of titanium dioxide, especially rutile titanium dioxide, which is mostly consumed by the paint industry. Coatings made of titanium dioxide have bright colors, strong tinting strength, strong dosage, low dosage, and many varieties, which can protect the stability of the medium, and can enhance the mechanical strength and adhesion of the paint film to prevent cracks. Prevents the penetration of UV rays and moisture and prolongs the life of the paint film.
The plastics industry is the second largest user. Adding titanium dioxide to plastics can improve the heat resistance, light resistance and weather resistance of plastic products, improve the physical and chemical properties of plastic products, enhance the mechanical strength of products, and prolong service life.
The paper industry is the third largest user of titanium dioxide. As a paper filler, it is mainly used in high-grade paper and thin paper. Adding titanium dioxide to the paper can make the paper have good whiteness, good gloss, high strength, thin and smooth, no penetration during printing, and light weight. Titanium dioxide for papermaking generally uses anatase titanium dioxide without surface treatment, which can act as a fluorescent whitening agent and enhance the whiteness of paper. However, the laminated paper requires the use of surface-treated rutile titanium dioxide to meet the requirements of light resistance and heat resistance.
Titanium dioxide is also an indispensable white pigment in advanced inks. The ink containing titanium dioxide is durable and does not change color, has good surface wettability and is easy to disperse. Titanium dioxide used in the ink industry has both rutile and anatase types.
The textile and chemical fiber industry is another important application area of titanium dioxide. Titanium dioxide for chemical fiber is mainly used as a matting agent. Since the anatase type is softer than the golden red type, the anatase type is generally used. Titanium dioxide for chemical fiber generally does not need surface treatment, but some special varieties need surface treatment in order to reduce the photochemical effect of titanium dioxide and avoid fiber degradation under the action of titanium dioxide photocatalysis.
Enamel industry is an important application field of titanium dioxide. Enamel-grade titanium dioxide has high purity, good whiteness, fresh color, uniform particle size, strong refractive index and high achromatic power, and has strong opacity and opacity, which makes the coating thin after enamel coating. Smooth and strong acid resistance, can be mixed with other materials evenly in the enamel manufacturing process, non-caking, easy to melt and so on.
The ceramic industry is also an important application field of titanium dioxide. Ceramic-grade titanium dioxide has high purity, uniform particle size, high refractive index, and excellent high temperature resistance. With high opacity, thin coating and light weight, it is widely used in ceramics, construction, decoration and other materials.
There are two methods of manufacturing titanium dioxide: sulfuric acid method and chlorination method. Among them, 56% are chlorination products, and more than 70% of these products are produced by large titanium dioxide factories such as DuPont in the United States. Titanium dioxide factories in other countries, including China, are still dominated by sulfuric acid method.
Sulfuric acid method: It is the acid hydrolysis reaction of titanium special iron powder with concentrated sulfuric acid to produce ferrous sulfate, which is hydrolyzed to generate metatitanic acid, and then calcined and pulverized to obtain titanium dioxide product. This method can produce anatase and rutile titanium dioxide. The advantage of the sulfuric acid method is that it can use cheap and easily available ilmenite and sulfuric acid as raw materials, the technology is relatively mature, the equipment is simple, and the anti-corrosion materials are easy to solve. The disadvantage is that the process is long, and it can only be operated intermittently. The wet operation has high consumption of sulfuric acid and water, many wastes and by-products, and causes great environmental pollution.
Chlorination method: The chlorination method is to mix rutile or high-titanium powder and coke, chlorinate titanium tetrachloride at high temperature, oxidize at high temperature, and then filter, wash, dry and seal to obtain titanium dioxide products. The chlorination method can only produce rutile-type products. The advantage of the chlorination method is that the process is short and the production capacity is easy to expand. The continuous automation is high, the energy consumption is relatively low, the "three wastes" are few, and high-quality products can be obtained.
According to the material characteristics of titanium dioxide, on the basis of digesting and absorbing foreign better equipment and technology, the self-developed rapid spin Flash Dryer has been successfully applied in titanium dioxide drying.

Device Description:
The flash Dryer is mainly composed of an air inlet system, a heating system, a feeding system, a drying host, a collecting and dust removal system, an exhaust system, and a control system. When working, the wet material enters the drying chamber from the screw feeder, and the material meets the hot air rotating at high speed in the drying chamber. After being crushed by the crushing device at the bottom, the material is quickly dispersed, and the contact area between the material and the hot air increases rapidly. Under the action of centrifugal force (there is a classification device on the top), the product that reaches the dryness and a certain fineness is blown out of the classification device, and the material is quickly dried in the process.


Features:
The flash dryer has the advantages of high technology content, high standardization, environmental protection, safety, low consumption, simple maintenance, etc. In the design structure:
①The bottom of the dryer is equipped with an inverted cone structure, so that the drying gas flow section gradually expands from bottom to top, the bottom airflow is relatively large, and the upper airflow is relatively small, so as to ensure that the large particles in the lower part are in a fluidized state, and the small particles in the upper part are in a fluidized state. The particles are also in a fluidized state, and the hot air rotates along the vertebral body, which increases the wind speed at the bottom, reduces the length of the cantilever part of the stirring shaft, and increases the safety and reliability of operation; the bearing can be placed outside the machine to effectively prevent the bearing from being exposed to high temperatures. Zone work, thereby extending the service life of the bearing.
②A scraper is set on the stirring teeth. When the material is crushed by the stirring teeth, it is thrown to the wall of the machine and adhered to the wall. If it is not scraped off in time, the equipment will vibrate in severe cases, and even cause the agitator to stop rotating. . The scraper is set on the stirring teeth, which can peel off the material sticking to the machine wall in time to avoid sticking to the wall.
③The rotation of the stirring shaft is controlled by the stepless speed regulating motor. Select different rotating speeds according to the product particle size requirements. The faster the stirring shaft rotates, the smaller the particle size of the product.
④A classifier is set on the upper part of the dryer. By changing the hole diameter of the classifier and the height of the classification section, the air flow rate is changed to control the size and quantity of particles leaving the dryer, the final moisture content and the residence time of the material in the drying section.
⑤The number of revolutions of the screw conveyor of the feeder is controlled by an inorganic speed-regulating motor. The feeding speed is controlled according to the material properties and drying process parameters.
⑥ The equipment has a compact structure and a small footprint. It integrates drying, crushing and classification. It is an organic combination of swirl technology, fluidization technology, spouting technology and convection technology. The production process saves power and equipment costs.