RU2514666C1 - Method of production of powder product from filtrate of distillery stillage - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: method comprises rough and fine dividing of distillery stillage in two separators located in parallel and fine filters, each of which is intermittently operated in the mode of dividing with the cake discharge and obtaining the filtrate and in the mode of counterflow regeneration of the filter elements. The filtrate obtained after the fine filter, at a concentration of dry substance of 4-5% is evaporated in a vacuum evaporator under discharge of 0.3-0.5 atm up to the concentration of dry substance of 30-40%. Then the concentrated solution is directed to a spray dryer, after which the powder product is obtained with the moisture content of 8-10% and a fineness of 70-80 microns. The exhaustion in the vacuum evaporator is created using a steam jet ejector installation comprising a steam generator, an ejector, a condenser, and a condensate collector and a pump, operating in the closed thermodynamic cycle.

EFFECT: invention enables to improve the quality of the powder product by storing it in of useful substances and vitamins, to reduce energy costs for the processes of evaporation and drying the filtrate, and to provide environmentally safe operating conditions of the equipment.

1 dwg, 2 tbl, 1 ex

Description

The invention relates to technological processes for the treatment of alcohol stillage, which is a by-product of alcohol production, and can be used in food, animal feed and other industries.

Known technological scheme of bardosus [Klimovsky D.N. Technology of alcohol / D.N. Klimovsky, V.N. Stabnikov. - M .: Pishchepromizdat, 1960. - 515 p.], Which provides for the separation of stillage into two fractions: suspended (pellet) and liquid (filtrate), evaporation of the filtrate in a multi-case vacuum-evaporation station with its subsequent drying on a surface drum dryer.

The disadvantages of this method are:

- low efficiency of separation of the original stillage into suspended and liquid fractions, since the use of centrifugal separators and fine filters is not provided;

- deterioration in the quality of the finished product due to the probability of its burning on the surface of the drum dryer due to the fact that steam is used with a pressure of 2 ... 4 atm and a relatively high temperature of 120 ... 140 ° C;

- additional energy costs for the processes of evaporation and drying of the filtrate, since it is not intended to use the heat of the exhaust steam after the ejector to heat the drying agent;

- environmental pollution due to lack of recirculation of the drying agent.

An object of the invention is to improve the quality of the finished product, reduce energy consumption and improve environmental friendliness when implementing this method.

To solve the technical problem of the invention, a method for producing a powdered product from an alcohol stillage filtrate is provided, characterized in that it provides for coarse and fine separation of the stillage in two separators and fine filters installed in parallel, each of which periodically operates in the separation mode with the removal of cake and obtaining a filtrate and in countercurrent water regeneration of filter elements; evaporation of the filtrate obtained after fine purification of the filtrate with a solids concentration of 4-5% in a vacuum evaporator under a vacuum of 0.3-0.5 atm and a boiling point of 70-80 ° C to obtain a condensed solution with a solids concentration of 30-40% , from which in a spray dryer receive a powdery product with a moisture content of 8-10% and a dispersion of 70-80 microns; while the vacuum in the vacuum apparatus is created by means of a steam ejector installation, including a steam generator, ejector, condenser, condensate collector and pump, which operate in a closed thermodynamic cycle, and one part of the working steam with a pressure of 1-1.2 atm is supplied from the steam generator to the heating chamber a vacuum evaporator, and the other with a pressure of 3-3.2 atm is sent to the ejector nozzle; then a mixture of vapors - spent working and ejected from a vacuum evaporator with a temperature of 110-120 ° C, is sent to a condenser for heating the air to a temperature of 75-80 ° C, followed by its supply to a spray dryer; from which the exhaust air is taken off to a heat exchanger-recuperator, where its temperature is reduced to the dew point and the droplet liquid contained in it is condensed in the amount of moisture evaporated from the product, and then the dried air after heating in the condenser is sent to a spray dryer with the formation of a closed cycle; and the condensates obtained after the heat exchanger-recuperator, heating the chambers of the vacuum evaporator and from the condenser are discharged to the condensate collector, from which one part of the condensate is pumped to the steam generator to replenish the water level in it, and the other is fed to the separator and fine filter operating in countercurrent water regeneration mode.

The technical result of the invention is to improve the quality of the finished product, reduce energy consumption and improve environmental friendliness when implementing this method.

The powdered product from the distillery distillery filtrate contains significant amounts of vitamins, which allows us to call this product a fortified concentrate. In its nutritional properties, it is approximately equal to skim milk. Adding it to the feed of hatchery chickens significantly reduces their mortality; its introduction into the diet of fattened poultry and young animals reduces the number of diseases and accelerates growth.

Figure 1 presents a diagram that implements the proposed method for producing a powdery product from a filtrate of alcohol stillage.

The circuit contains separators 1, 3; fine filters 2, 4; vacuum evaporator 5; ejector 6; capacitor 7; reducing valve 8; condensate collector 9; pumps 10, 13; safety valve 11; a steam generator 12; spray dryer 14; heat exchanger-recuperator 15; fan 16; valve 17; material flow lines: 0.1 - powdery product; 0.8 - cake bards; 1.0 - waste water; 1.6 - cold water; 1.8 - condensate; 2.0 - steam worked; 2.2 - working steam; 2.7 - a mixture of working and exhaust steam; 3.0 - waste drying agent; 3.3 - drying agent; 9.1 - source bard; 9.7 - bard filtrate; 9.8 - condensed filtrate.

A method of obtaining a powdery product from a distillery stillage filtrate is as follows.

The original stillage from the hardware department of the distillery is fed to a separator 1, in which it is roughly divided into cake and filtrate. Next, the filtrate through line 9.7 is sent for fine separation into a fine filter 2, after which the cake is connected to the cake obtained after separator 1, and discharged along line 0.8, and the filtrate with a solids concentration of 4 ... 5% is fed to a vacuum evaporator 5.

The filtrate in the apparatus 5 is evaporated under a vacuum of 0.3 ... 0.5 atm and a condensed solution with a solids concentration of 30 ... 40% is obtained, which is sent to the spray dryer 14 using a valve 17 via line 9.8. A powder product is obtained at the outlet of the dryer 14. with a humidity of 8 ... 10% and a dispersion of 70 ... 80 microns.

The vacuum in the apparatus 5 is created using a steam ejector installation, including a steam generator 12, an ejector 6, a condenser 7, a condensate collector 9 and a pump 13 operating in a closed thermodynamic cycle.

The working steam obtained in the steam generator 12 with a pressure of 3 ... 3.2 atm is divided into two parts, one of which is sent via line 2.2 to a pressure reducing valve 8 to reduce the pressure to 1 ... 1.2 atm, and then to the heating chamber of the vacuum evaporator 5, and the other part of the working steam with a pressure of 3 ... 3.2 atm - into the ejector nozzle 6. Vapors ejected along line 2.0 from a vacuum apparatus create a vacuum of 0.3 ... 0.5 atm at a boiling point of a solution of 70 ... 80 ° FROM. This temperature allows you to save in the solution such useful substances as vitamins (riboflavin, thiamine, nicotinic acid, pantothenic acid, biotin, choline), crude protein, carbohydrates.

A mixture of spent working and ejected vapors with a temperature of 110 ... 120 ° C is sent via line 2.7 to a condenser 7, in which air is heated to a temperature of 75 ... 80 ° C due to regenerative heat exchange. Heated air by fan 16 on line 3.3. served in the spray dryer 14. Using a spray dryer can reduce the duration of the drying process, which can be from 15 to 30 seconds. The temperature of the product particles in the drying chamber is almost equal to the temperature of evaporation of pure moisture. This is due to the fact that the particles have a saturated surface. Drying takes place almost instantly. In combination with the low temperature of dispersible particles of the product, this allows to obtain a high-quality powdery product. This drying method does not cause protein denaturation, oxidation and loss of vitamins.

The exhaust air from the dryer 14 is discharged through line 3.0 to a heat exchanger-recuperator 15, where cold water is supplied via line 1.6, and waste water is discharged through line 1.0. Due to the regenerative heat exchange between cold water and the exhaust air after the dryer, its temperature decreases to the dew point. In this case, condensation of dropping liquid contained in the exhaust air is carried out in the amount of moisture evaporated from the product on the cooling surface of the heat exchanger-recuperator. Thus dried air through line 3.3 is directed first to the condenser 7, and then again to the spray dryer 14 with the formation of a closed cycle.

The condensate formed after the heat exchanger-recuperator 15 together with the condensate after the heating chamber of the vacuum evaporator 5 and the condenser 7 is led through lines 1.8 to the condensate collector 9. In this case, one part of the condensate from the collector 9 is pumped by pump 13 to a steam generator 12 equipped with a safety valve 11, to replenish the water level in it. Another part of the condensate is pumped into the separator 3 and the fine filter 4, operating in countercurrent water regeneration mode, to restore the throughput of the filter elements.

An example implementation of the method.

The method is implemented in a production environment on a line with a capacity of the initial bard 5.2 t / h.

The original bard from the hardware department of the distillery is fed to a separator, in which it is roughly divided into cake and filtrate. Next, the filtrate is sent to a fine separation in a fine filter.

The cake after the fine filter is combined with the cake obtained after the separator, and in an amount of 0.7 t / h is discharged into a collector (not shown in the diagram), and the filtrate in an amount of 4.5 t / h with a solids concentration of 4% is fed into vacuum evaporator. The filtrate in the apparatus is evaporated under a vacuum of 0.3 atm and a condensed solution with a solids concentration of 35% is obtained, which is sent in an amount of 0.5 t / h to a spray dryer. Drying is carried out with air heated to a temperature of 75 ° C, which is fed by a fan in an amount of 20 t / h into the dryer body.

At the outlet of the spray dryer receive a powdery product in an amount of 0.2 t / h with a moisture content of 9% and a dispersion of 70 ... 80 microns.

The vacuum in the vacuum apparatus is created using a steam ejection plant with a capacity of 16 t / h, including a steam generator, ejector, condenser, condensate collector and pump, operating in a closed thermodynamic cycle.

The working steam obtained in the steam generator with a pressure of 3.0 atm is divided into two parts, one of which in the amount of 4.1 t / h is sent to a pressure reducing valve to reduce the pressure to 1.2 atm, and then to the heating chamber of the vacuum evaporator, and the other part of the working steam in the amount of 16 t / h with a pressure of 3.2 bar - into the ejector nozzle. The ejected vapors from the vacuum apparatus equal to the amount of moisture evaporated from the filtrate 4 t / h create a vacuum of 0.3 atm at the boiling point of the solution 75 ° C.

A mixture of spent working and ejected vapors with a temperature of 110 ° C in an amount of 20 t / h is sent to a condenser, in which, due to regenerative heat exchange, the air exhausted after the spray dryer is heated from a temperature of 23 ° C to a temperature of 75 ° C.

Exhaust air from a dryer with a temperature of 40 ° C in an amount of 21.2 t / h is discharged into a heat exchanger-recuperator, where cold water is supplied from a water supply network with a temperature of 15 ° C in an amount of 9 t / h. Due to the regenerative heat exchange between cold water and the exhaust air after the dryer, its temperature decreases to 23 ° C, which is lower than the dew point temperature under these conditions. Therefore, condensation of the dropping liquid contained in the exhaust air is carried out in the amount of moisture vaporized from the product 1.2 t / h on the cooling surface of the heat exchanger-recuperator.

Thus dried air is directed first to a condenser for heating, and then again to a spray dryer with the formation of a closed cycle.

The condensate formed after the heat exchanger-recuperator together with the condensate after the heating chamber of the vacuum evaporator and condenser with a total capacity of 25.3 t / h is discharged to the condensate collector. In this case, one part of the condensate in an amount of 20 t / h from the collector is sent by a pump to a steam generator equipped with a safety valve to replenish the water level in it. The other part of the condensate is pumped into the separator and fine filter, operating in countercurrent water regeneration mode to restore the throughput of the filter elements.

The characteristics of the equipment used in the line are presented in table 1.

Tab. one

A comparative analysis of the finished powdery product from the distillery stillage filtrate obtained by the existing and proposed technology is presented in table 2.

Tab. 2

As can be seen from the example and table 2, the proposed method for producing a powdery product from the filtrate alcohol distillery stillage makes it possible:

- improve the quality of the resulting powdery product by preserving in it useful substances and vitamins;

- reduce energy costs through the use of a steam ejector installation and a recirculation loop for a drying agent;

- reduce energy costs for the processes of evaporation and drying of the filtrate due to the use of the heat of the exhaust steam after the ejector to heat the air before feeding it to the spray dryer;

- to increase the efficiency of separation of the initial stillage into suspended and liquid fractions and the quality of the finished powder product through the use of a spray dryer using air with a low temperature of 75 ... 80 ° C as a drying agent;

- eliminate environmental pollution during the drying process due to the presence of a recirculation loop through the drying agent and ensure environmentally friendly operating conditions of the equipment.

If you change the process parameters and drying modes in the direction of decreasing or increasing, this will lead to a decrease in the quality of the finished powder product and an increase in energy consumption for its production.

Claims (1)

A method for producing a powdered product from an alcohol stillage filtrate, characterized in that it provides for coarse and fine separation of the stillage in two parallel separators and fine filters, each of which periodically operates in the separation mode with the removal of cake and obtaining the filtrate and in countercurrent water regeneration of filtering elements, evaporation of the filtrate obtained after fine purification of the filtrate with a solids concentration of 4-5% in a vacuum evaporator under a vacuum of 0.3-0.5 atm and t boiling point 70-80 ° C to obtain a condensed solution with a solids concentration of 30-40%, from which a powder product with a moisture content of 8-10% and a dispersion of 70-80 μm is obtained in a spray dryer, while the vacuum in the apparatus is created by a steam ejector installation, including a steam generator, ejector, condenser, condensate collector and pump, which operate in a closed thermodynamic cycle, with one part of the working steam with a pressure of 1-1.2 atm from the steam generator being fed into the heating chamber of the vacuum evaporator, and another - with a pressure of 3-3.2 atm is sent to the ejector nozzle, then a mixture of vapors - spent working and ejected from a vacuum evaporator with a temperature of 110-120 ° C is sent to a condenser to heat the air to a temperature of 75-80 ° C followed by by feeding it to a spray dryer, from which the exhaust air is taken off to a heat exchanger-recuperator, where it is lowered to the dew point and the droplet liquid contained in it is condensed in the amount of moisture evaporated from the product, and then the dried air after heating to the condensate the atomizer is sent to a spray dryer with the formation of a closed cycle, and the condensates obtained after the heat exchanger-recuperator, the heating chamber of the vacuum evaporator and from the condenser are taken to a condensate collector, from which one part of the condensate is sent by a pump to the steam generator to replenish the water level in it, and the other is fed into the separator and fine filter, operating in countercurrent water regeneration mode.