OPTIMIZATION OF THE CRYSTALLIZATION PROCESS IN THE PRODUCTION OF SODIUM SILICATE PENTAHYDRATE FROM LIQUID GLASS

ABSTRACT

Scientific research of technological production systems, equipment and methods for producing sodium silicate pentahydrate are analyzed. The scientific research illustrated that optimum values were analyzed by mathematical and statistical processing of experimental studies on the crystallization process in the production of sodium silicate pentahydrate from liquid glass. Based on the developed regression equation, an algorithm was developed to determine the optimal value of natural variables (liquid glass thickness, temperature, and processing time of duration), and based on this, a program was created in the Delphi programming language.

АННОТАЦИЯ

Проанализированы научные исследования технологических систем производства, оборудования и методы получения пентагидрата силиката натрия. Научные исследования показали, что оптимальные значения проанализированы путем математической и статистической обработки экспериментальных исследований процесса кристаллизации при производстве пентагидрата силиката натрия из жидкого стекла. На основе разработанного уравнения регрессии был разработан алгоритм определения оптимального значения натуральных переменных (толщина жидкого стекла, температура и длительность обработки) на языке программирования Delphi.

Keywords: optimization, liquid glass, sodium silicate pentahydrate, crystallization, temperature, processing time of  duration, Delphi, algorithm, motor, vacuum, analysis, structure.

Ключевые слова: оптимизация, жидкое стекло, силикат натрия пентагидрата, кристаллизация, температура, продолжительность процесса, Delphi, алгоритм, двигатель, вакуум, анализ, структура.

Introduction. Scientific research of technological production systems, equipment and methods for producing sodium silicate pentahydrate are analyzed. It is true that increasing the competitiveness of products produced in the country in the chemical industry in the world market, developing exports, expanding local production enterprises and workshops, increasing the type of environmentally friendly, high-quality products, as well as implementing energy-saving, simple, compact modern equipment by improving low-efficiency devices is one of the urgent problems of today.

On the one hand, one of the main sectors of production enterprises in Uzbekistan is the chemical industry, but many chemical products are imported and used by export from foreign countries. These types of chemical products include sodium silicate pentahydrate and others.

On the other hand, studies have been conducted by foreign scientists on the production of sodium silicate pentahydrate. In particular, scientists from China, Russia, Ukraine, USA, India, Belarus and other countries are making their contribution.

Scientific analyzes show that scientific article published by Belarusian scientists, it is said that in the technology of production of hydrated silicate powders from liquid glass, the structure of the spray drying apparatus consists of a cylindrical part with a diameter of 5800 mm, a height of 4500 mm, and a conical part with a height of 3100 mm. The body of the dryer is made of stainless steel, the outer part is thermally insulated with mineral wool plates covered with tin. In this dryer, the temperature is in the range of 180-220 ℃, the number of revolutions of the disk motor is 14000 rpm/s, the vacuum pressure in the dryer is 100-150 MPa, and the influence of other influencing factors is determined [1].

Figure 1. Technological scheme of production of hydrated sodium silicate in the form of powder

The number of technological parameters set for this system is high and leads to an increase in energy costs.

An invention patent obtained by Chinese scientists describes a continuous system for the production of sodium metasilicate pentahydrate. Through heat radiation structure's internal construction, through its inner chamber evaporation liquid repeated evaporation liquefaction process, accomplish thermal transmission to reach the effect to inside liquid cooling-up, through control by temperature change check out test set and the cooperation of energy storage mechanism, make heat radiation structure reversal, it is rotatory to drive rotatory ring, and the flowing back is assisted to flowing back and filtering mechanism to automatic start valve mechanism open flowing back and reducing the reliance to the manual work [2].

In the analysis of this study, the devices used in the system have a complex structure, which leads to an increase in the cost.

Research methods and equipment. Based on this, the crystallization process for the production of sodium silicate pentahydrate from liquid glass was studied and a laboratory device was created for conducting experiments (Figure 2).

Figure 2. Drum crystallizer

1-drum, 2-heat exchanger, 3-knife, 4-bearing, 5-valve

The principle of operation of the device is as follows. Liquid glass is poured into the drum crystallizer bath. To accelerate the crystallization process, the liquid glass temperature is increased to 60-70 ℃. For this, hot water is supplied from the bottom of the bath, which serves to increase the temperature of the liquid glass. The drum moves continuously and presses the liquid glass on its outer surface. In the conducted experiment, the influencing factors are the temperature of the product at 130-150 ℃, the thickness of the product is 0.5-2 mm, and the duration of the crystallization process is 120-180 seconds. Also, due to the high number of water molecules of the product in the upper part of the layer, it is heated at a temperature of 130-150 ℃ with the help of an electric heater, and the water molecular number is close to 5. After that, the number of water molecules in the product decreases and crystallizes under the influence of heat. As a result, the drum is cleaned with the help of blades after one complete revolution.

Research results and discussion. As a result of mathematical and statistical processing of the experimental results, a regression equation was obtained that describes the dependence of the moisture content of sodium silicate pentahydrate on the influencing factors in the crystallization process [3].

              (1)

We changed equation (1) into a natural form to construct graphs using the Response Surface Methodology.

The resulting graphs are shown in Fig. 3.

Figure 3. Graph of dependence of sodium silicate pentahydrate on the number of water molecules

An algorithm for determining the optimal values of the factors affecting the crystallization process was created and illustrated in Fig. 4.

Figure 4. Algorithm for determining optimal values

According to this algorithm, a program for determining optimal values was developed in the Delphi programming language [4]. Limit values of influencing factors are shown in the program. Also, the optimal value of the output factor is 5. That means sodium silicate pentahydrate has the number of water molecules. The screen view of the built program is presented in Fig. 5.

Figure 5. Program interface

Conclusion. For the crystallization process, the number of water molecules should be equal to 5, which is represented by the chemical formula . The following results were obtained when the limit values of the influencing factors were indicated in the developed program. The temperature of the liquid glass is 147℃, the thickness is 1.1 mm, and the duration of the process is 160 seconds.

References:

1. Industrial technology of hydrated silicate powders from liquid glasses / M. I. Kuzmenkov, S. I. Masyuk, A. M. Grechny, A. M. Kozel // Construction materials monthly scientific, technical and production magazine. M.; Construction materials; 1998. 2013. - No. 11. - pp. 26-27.
2. 金龙 (Jing Long), Continuous production process and device of sodium metasilicate pentahydrate, patents.google.com, CN113955764A, China. 2022-01-21.
3. Sh.R.Ibragimov et al., Mathematical model of the process of liquid glass crystallization in the production of sodium silicate pentahydrate. UNIVERSUM: TECHNICAL SCIENCES, Scientific journal Issue: 2(119), Part 6 – Moscow: 2024. – 32-36 p.
4. Sh.R.Ibragimov, Software for determining the optimal values of technological parameters in the process of crystallization of the production of sodium silicate pentahydrate from liquid glass // Certificate of the Intellectual Property Agency of the Republic of Uzbekistan. No. DGU 37873, 05/15/2024