CN103013169B - A kind of spray drying method of azo organic dye aqueous solution - Google Patents

Abstract

The invention discloses a spray-drying method of an azo-type organic dye aqueous solution, which is characterized in that it is carried out according to the following steps: quantitatively weigh the azo-type organic dye aqueous solution to be spray-dried, start stirring, add an appropriate amount of water-soluble anti-coking agent, After fully stirring and mixing evenly, send it to a spray dryer for drying. The method can overcome the disadvantages of dull dye color and decreased dye strength caused by spray drying of the conventional azo organic dye aqueous solution, and the process is simple and easy to realize.

Description

A kind of spray drying method of azo organic dye aqueous solution

technical field

The invention relates to a drying method of organic dyes; in particular, it relates to a spray drying method of an azo organic dye aqueous solution.

Background technique

There are many types of azo dyes, complete color spectrum, high quality and low price, and are mainly used in textile and paper making industries. In recent years, the competition in the dye industry has become increasingly fierce, so all dye manufacturers are constantly optimizing the production process, trying to reduce production costs, so that they can occupy a favorable position in the market competition. In the production process of azo dyes, the prepared dye aqueous solution is usually salted out, filtered, concentrated or dried to finally be made into powdery dyes or high-concentration liquid dyes. The traditional dye production process mainly uses salting-out to separate the dye components. Not only is the product purity not high, but there are batch-to-batch differences in the product quality of different batches, it is difficult to ensure the stability of product quality, and inorganic salts are also used in the salting-out process, so A large amount of salty wastewater is produced during the filtration process, and the discharge of these wastewaters has caused great pollution to the environment, seriously restricting the sustainable development of the dye industry. In recent years, in order to avoid the discharge of a large amount of salt-containing dye wastewater during the dye production process, while ensuring stable dye product quality and avoiding product batch differences, many dye companies at home and abroad have adopted spray drying technology to dry the synthetically prepared dye aqueous solution. The parameters of the dye spray drying process are usually selected: the inlet air temperature is 220°C-280°C, and the outlet air temperature is 90°C-110°C. Because the obtained dye product is granular, dust-free, easy to disperse and dissolve, and the product quality is stable, etc., Therefore, the spray drying technology is deeply favored by dye companies and has been widely promoted and applied in the dye industry. However, azo dyes are relatively poor in high-temperature thermal stability. During the drying process using spray drying technology, high-temperature air will cause thermal decomposition of azo dyes and cause coking, which will lead to dark color of dye products and a significant reduction in dye strength. Shortcomings. Therefore, how to avoid the thermal decomposition of azo dyes during the spray drying process and ensure the improvement of dye quality and strength is one of the urgent problems in the dye industry.

Contents of the invention

The object of the present invention is to provide a spray-drying production method of an azo organic dye aqueous solution. This method can overcome the disadvantages mentioned above.

The object of the present invention is achieved by the following technical solutions: a spray drying method of an azo organic dye aqueous solution is characterized in that it is implemented according to the following steps: quantitatively weigh the azo organic dye aqueous solution to be spray-dried, start Stir, add an appropriate amount of water-soluble anti-scorching agent, fully stir and mix evenly, and send it to a spray dryer for drying.

The dye concentration of the dye aqueous solution described in the above technical scheme is 1-50%;

The spray dryer described in the above technical solution has an inlet air temperature of 200°C to 280°C and an outlet air temperature of 90°C to 110°C;

The water-soluble anti-coking agent described in the above-mentioned technical scheme is sodium sulfite, sodium bisulfite, sulfamic acid, or one or its mixture in sodium metabisulfite;

The addition of an appropriate amount of water-soluble anti-scorching agent described in the above technical scheme, its addition is 0.1% to 2% of the weight of the organic dye in the synthetically prepared azo dye aqueous solution;

Compared with the prior art, the present invention has many advantages and positive effects

1. The spray-drying method of a kind of azo-type organic dye aqueous solution of the present invention can overcome the shortcoming that the color of the dye product caused by spray-drying in the existing azo-type organic dye production process is dark and the intensity is reduced.

2. The process of the present invention is simple and reasonable, and is convenient for implementation and popularization.

Detailed ways

The spray-drying method of a kind of azo organic dye aqueous solution of the present invention is implemented according to the following steps: quantitatively weigh the azo organic dye aqueous solution to be spray-dried, start stirring, add an appropriate amount of water-soluble anti-coking agent, and fully stir After mixing evenly, send it to a spray dryer for drying.

The present invention will be further described in detail below by way of examples.

Example 1

Take by weighing Direct Fast Black G commercial dye (dye strength 100%), and use deionized water configuration concentration to be 13% Direct Fast Black G dye solution for subsequent use; Weigh Direct Fast Black G commercial dye (dye strength 100%) , use deionized water to prepare a dye solution with a concentration of 13%, then add sodium sulfite accounting for 0.5% of the dye content, and stir evenly to obtain a direct sunfast black G dye solution with an additive concentration of 12% for use; start the LPG type high-speed centrifuge Spray dryer, control the inlet air temperature of the high-speed centrifugal spray dryer to 270±5°C, and the outlet air temperature to 100±5°C to dry the above-mentioned dye solution to obtain dry direct sunfast black G dye powder and additive direct Fast Black G Dye Powder. According to the national standard GB/T6688-2008, the relative strength of the obtained dye powder is tested, and the results show that the relative strength of direct sunfast black G dye without additives is 85%, and the relative strength of direct sunfast black G dye with sodium sulfite is 95%. .

Example 2

It is basically the same as in Example 1, except that the inlet air temperature of the high-speed centrifugal spray dryer is adjusted to 240±5°C. The results show that the relative strength of the direct sunfast black G dye without additives is 91%, and the direct sunfast black with additives is 91%. The relative intensity of G dye is 96%.

Example 3

It is basically the same as in Example 2, except that direct sunfast black G commercial dye (100% dye strength) is replaced with direct black 22 (dye strength 150%)), and the results show that the relative strength of the dyestuff without additive direct black 22 is 138 %, the relative strength of additive Direct Fast Black 22 dye is 144%.

Example 4

It is basically the same as in Example 2, except that the direct sunfast black G commercial dye (100% dye strength) is replaced by direct acid-fast scarlet 4BS (dye strength 200%), and the results show that the relative strength of the dyestuff without adding any direct acid-fast scarlet 4BS is 182%, and the relative strength of direct acid-fast scarlet 4BS dye with additive is 192%.

Example 5

Substantially the same as Example 2, only the dye concentration of the direct sunfast black G commercial dye (100% dye strength) aqueous solution is increased to 20%, the result shows that the relative intensity of the direct sunfast black G dye without additive is 91%, The relative strength of the additive Direct Fast Black G dye is 96%.

Example 6

It is basically the same as Example 3, except that sodium sulfite is replaced by sodium bisulfite, and the results show that the relative intensity of direct black 22 dye without additive is 140%, and the relative intensity of direct black 22 dye with additive is 148%.

Example 7

It is basically the same as in Example 3, except that sodium sulfite is replaced with sulfamic acid, and the results show that the relative intensity of direct black 22 dye without additive is 134%, and the relative intensity of direct black 22 dye with additive is 143%.

Example 8

It is basically the same as Example 2, except that sodium sulfite is changed into sodium sulfite and sodium bisulfite in a weight ratio of 1: 1, the results show that: the relative strength of the direct black 22 dye without additive is 135%, and the relative strength of the direct black 22 dye with additive is 135%. Strength is 144%.

Example 9

Substantially the same as in Example 3, except that sodium sulfite is replaced by sodium sulfite and sulfamic acid in a weight ratio of 1:1, the results show that the relative intensity of direct black 22 dye without additive is 131%, and the relative intensity of direct black 22 dye with additive is 144%.

Example 10

It is basically the same as in Example 3, except that sodium sulfite is replaced by sodium bisulfite and sulfamic acid with a weight ratio of 1: 1. The results show that the relative strength of the direct black 22 dye without additive is 130%, and the direct black 22 dye with additive is 130%. The relative strength of 143%.

Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the above examples. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention shall all belong to protection scope of the present invention.

Claims (1)

1. a spray-drying method of an azo organic dye aqueous solution is characterized in that it is implemented in the following steps: quantitatively take the azo organic dye aqueous solution to be spray-dried, start stirring, add an appropriate amount of water-soluble anti-coking agent, fully After stirring and mixing evenly, send it to a spray dryer for drying to obtain a powdery dye product. The spray dryer described in the above technical solution has an inlet air temperature of 200°C to 280°C and an outlet air temperature of 90°C to 110°C; The dye concentration of the dye aqueous solution described in the above technical solution is 1-50%; the above-mentioned water-soluble anti-scorching agent is one of sodium sulfite, sodium bisulfite, sulfamic acid, or sodium metabisulfite or a mixture thereof; The added amount is 0.1%-2% of the weight of the organic dye in the azo organic dye aqueous solution.