PARAMETER CONTROL IN THE EXTRACTION AND DISTILLATION UNIT

ABSTRACT

This article discusses the technology of extracting plant materials with organic solvents or steam stripping for complete extraction of oils, automation and description of an experimentally developed industrial unit using a heat pump and a solar collector for the extraction process and distillation of oil from fruit seeds. The goal of automation of the experimentally developed industrial extraction-distillation unit is to achieve stable operation with maximum extractor productivity, ensuring high miscella concentration and oil removal depth, with minimal solvent and energy costs. The issue of stabilizing the solvent flow is also being addressed through a single-circuit control system consisting of a flow meter, a microcontroller and a control valve installed on the solvent supply line, and to increase the accuracy of regulating the composition and quality of the product, devices with an automatic calibration device for composition analyzers are used.

АННОТАЦИЯ

В данной статье рассматриваются технология экстрагирования растительного сырья органическими растворителями или отгонке паром для полного извлечения масел, автоматизация и описание разработанной экспериментально – опытно – промышленной агрегатной установки с применением теплового насоса и солнечного коллектора для процесса экстракции, и дистилляции масла из плодовых косточек. Целью автоматизации разработанного экспериментально – опытно – промышленного экстракционно-дистилляционного агрегата является достижение стабильной ее работы при максимальной производительности экстрактора, обеспечение высокой концентрации мисцеллы и глубины съема масла, при минимальных затратах растворителя и энергозатратах. Также решается вопрос стабилизации расхода растворителя за счет одноконтурной системы управления, состоящей из расходомера, микроконтроллера и регулирующего клапана установленного на линии подачи растворителя, а для повышения точности регулирования состава и качества продукта применяют приборы с устройством автоматической калибровки анализаторов состава.

Keywords: Process, Food, Microcontroller, Extraction, Automation, Control System.

Ключевые слова: процесс, пищевой, микроконтроллер, экстракция, автоматизация, система управления.

Introduction. The extraction of essential oils from plant materials is based on extraction with organic solvents or steam distillation. This allows significant losses of volatile fragrant substances and leads to a disruption of the natural balance of components in the composition of essential oils and to an undesirable decrease in their quality [2,3].

In accordance with the existing theory, preparing raw materials for pressing is to destroy the cells of oilseeds as much as possible during the grinding process. And in the process of moisture-heat treatment, weaken the forces holding the oil in the cell by increasing the plasticity of the cell membrane by moisturizing and then drying it to give it certain elastic properties that provide pressing conditions [1,2,4,6].

In the technology for extracting medicinal oils from the kernels of fruit seeds, grape seeds, etc., the oil is extracted from the raw material by cold triple pressing. In this case, the yield is up to 30-40% of the total amount of oil in the raw material.

The development of methods of energy-resource-saving technologies that make it possible to obtain new high-quality products in the pharmaceutical, perfume and food industries is due to the urgent public need for high-quality medicines and food, as well as for environmentally friendly production [3,4].

Methods and subject of research. At the department of “Information and communication systems for managing technological processes” of the Bukhara Engineering and Technology Institute, scientific research work was carried out, as a result of which an experimental installation was created and assembled for the extraction and distillation of oil from stone fruits [4,5,6].

The automation scheme of the experimental installation for the extraction and distillation of oil from fruit seeds consists of three single-circuit automatic control systems, each of which performs one of the control tasks.

Results and discussion. The technological scheme of the developed and manufactured pilot industrial unit using a heat pump and a solar collector for extracting extracts from plant raw materials using the direct extraction method consists of an extractor - irrigation E, heat exchanger T, distiller D, condenser K, heat pump compressor TH, pumps H₁, H₂ and H₃, solar collector CK, and container E for solvent accumulation.

Oil extraction by extraction is carried out in the following order: a cassette with crushed oil material is inserted into the extractor E and the required amount of solvent is poured into the container E.

The heat exchanger, insulated from the outside, is filled with water and heated to a temperature of 85 - 90 ⁰C from the heat pump condenser and solar collector.

Then taps K₁ and K₉ are opened, taps K₂ and K₁₀ are closed, the pump is turned on and irrigation of the oily material located in the extractor cassette with solvent begins. After the accumulation of the required ratio of the amount of solvent to the extracted raw material in the conical bottom of the extractor, valve K₁ is closed. By opening tap K₂, the oilseed material is further irrigated with a circulating solvent in a closed system using a pump. When the miscella circulates through the heat exchanger, the miscella is heated to 55 - 60 ⁰C, which is necessary to intensify the extraction process.

After the extraction process is completed, tap K₁₀ opens and tap K₉ closes, and all the miscella from the extractor is pumped into the distiller. Upon completion of pumping the miscella, pump is turned off, valves K₂ and K₁₀ are closed, the extractor is loaded with a new portion of oilseed material and the cycle is repeated.

The miscella, pumped over by the pump, is sprayed by a nozzle located at the top of the distiller. In the distiller, the miscella is circulated by a pump through a heat exchanger by opening tap K₅. By heating the miscella to a temperature of 55-60⁰C and spraying it, intense evaporation of the solvent from the miscella begins. Solvent vapors enter the condenser through a drop eliminator, where they condense on the surface of the heat pump evaporator and the condensate is returned to the tank.

At the end of the distillation process, taps K₃ are closed, the pump stops and tap K₆ is opened. The resulting oil is sent for purification.

The extraction process continues until 97% of the oil contained in the material is isolated, the distillation process continues until 99,2% of the solvent contained in the miscella is evaporated [5,6].

The functional diagram of the automation of the extraction-distillation unit is shown in Fig. 1.

To stabilize the solvent flow, a single-circuit control system is provided, consisting of a flow meter, a microcontroller and a control valve installed on the solvent supply line.

The automatic temperature control system for the miscella after the heat exchanger consists of a temperature sensor that measures the temperature and converts it into a unified signal. This signal is measured by a microprocessor microcontroller. The temperature in the condenser and solar collector is controlled in a similar way.

Figure 1. Automation scheme of the extraction and distillation unit

The oil concentration at the outlet of the distiller is measured by a concentrator; the converted unified signal after the concentration meter is sent to the input of a microcontroller which generates a control signal to change the position of the control body of the actuator.

In this process, an important role is played by the precise maintenance of the quality parameter - the concentration of the miscella. This parameter is characterized by the complexity of measurement. In some cases, the chromatographic method is used to measure the composition. In this case, the measurement result is known at discrete moments of time, spaced from each other by the duration of the chromatograph operating cycle. A similar situation arises when the only way to measure product quality is mechanized sample analysis.

Discreteness of measurement leads to significant additional delays and a decrease in the dynamic accuracy of regulation (Fig.2). To reduce the undesirable impact of measurement delay, we use a model of the relationship between product quality and variables that are measured continuously. We refine the model coefficients by comparing the value of the qualitative parameter calculated from it and the value of the qualitative parameter found as a result of the next analysis. Thus, one of the rational ways to regulate quality is to regulate according to an indirect calculated indicator with clarification of the algorithm for its calculation based on direct analysis data. In the intervals between measurements, the product quality indicator is calculated by extrapolating previously measured values [4,5,6].

Figure 2. Block diagram of the ACS of the product quality parameter:

1 – object; 2 – quality analyzer; 3 – computing device; 4 – regulator.  - regulatory impact;  - where is the quality indicator assessment;  - qualitative parameter according to direct analysis data

The computing device continuously calculates the quality score

,

- where is the quality indicator assessment;

- miscella concentration – a qualitative parameter;

- miscella concentration at time i;

 - qualitative parameter according to direct analysis data;

F₁ and F₂ are functions.

In which the first term reflects the dependence of x on continuously measurable process variables dynamically related to them, and the second reflects the output of the extrapolating filter.

To improve the accuracy of composition and quality control, devices with an automatic calibration device are used. In this case, the control system periodically calibrates the composition analyzers, adjusting their characteristics [2,5,6].

Conclusion. The goal of automating an extraction-distillation unit is to achieve stable operation with maximum extractor productivity, ensuring high miscella concentration and oil removal depth, with minimal solvent and energy costs.

References:

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3. Kasyanov G.N., Korobitsyn V.S.; Extraction of valuable components from plant raw materials by methods of pre- and supercritical CO2 extraction: - monograph, State. education institution of higher education prof. education Kuban. state tech. University - Krasnodar: Publishing House - South, 2010, - 132 p.
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5. Safarov A.F., Gafurov K.H., Khikmatov D.N. Kholikov A.A. Energy and resource saving technologies in the processing of fruits and vegetables (Monograph). Bukhoro: “Durdona”, 2013. – 247 p.
6. Yamaletdinova M. F. Researching the process of heat treatment of apricot kernels based on the development of multifactorial experimental plan.// International Journal of early childhood special education (INT-JECS) vol 14, Issue 07 2022. pp.1552-1557.