RU2798054C1 - Beet processing section with column diffusion device - Google Patents

Abstract

FIELD: sugar industry.

SUBSTANCE: invention is related to equipment for extracting target components from plant materials. Beet processing section with a column diffusion apparatus contains a beet shavings trap, a diffusion juice heater, a column diffusion device, a water separator, a sand trap for pulp press water, a barometric water collector, a sulphurator, a collector of sulphated barometric water, a pump for supplying barometric water, a pump for supplying fresh pulp water, a pump for supplying settled pulp press water, a pump for supplying clarified diffusion juice, a pump for supplying a juice mixture, a pump for pumping diffusion juice into a sand trap, a pulp press water collector, a scalder, a diffusion juice sand trap interconnected by pipelines. The column diffusion device includes a vertical cylindrical body, inside of which a pipe shaft is installed along the axis with a bladed transport device fixed in a spiral, which ensures the supply of the juice mixture from the bottom up. A horizontal sieve is fixed in the lower part of the body of the column diffusion device to separate the diffusion juice removed from the device. The beet processing section with a column diffusion device is additionally equipped with an exhaust fan and a heat pump unit, consisting of a compressor, a liquid evaporator for extracting heat from the pulp press water removed from the water separator, an air evaporator for utilizing exhaust air from the beet processing section, a compressor, two condensers, one of which is designed for heating barometric water, and the other for heating pulp water before supplying heated barometric water and heated pulp press water to the column diffusion device, two thermostatic valves to control the temperatures of barometric water and pulp press water before they enter the column diffusion device, a pump for supplying sulphated barometric water into the liquid evaporator and a receiver designed to create a protective water seal between the liquid and air evaporators and condensers for heating barometric water and pulp water, also interconnected by pipelines.

EFFECT: reduction of heat consumption for diffusion process due to the return of part of the utilized heat from the obtained pulp water and from the heated air from the beet processing section.

1 cl, 3 dwg

Description

The claimed invention relates to equipment for extracting target components from vegetable raw materials and can be used in the sugar industry to equip a beet processing department with a column diffusion apparatus, as well as in the canning industry to obtain an extract from apple pomace in order to extract macro- and micronutrients, aromatic, coloring , pectin, minerals and organic acids.

A device "Column diffusion apparatus" (A.S. No. 1835861, C13D 1/1, publ. 27.04.1996, Bull. No. 12) is known, containing a cylindrical body with technological nozzles and counterblades fixed on its inner surface, installed inside the body , transport blades fixed on it in height, having upper working surfaces, and in the upper part - unloading blades, located in the lower part of the housing, a horizontal sieve for separating juice from chips and a chute for pulp removal located outside the housing. The unloading blades are attached to the pipe shaft with an offset relative to the transport blades of the last row in the direction opposite to their movement at an angle of 15 - 30 ^o , while the working surface of each unloading blade is inclined to the housing wall at an angle to the horizontal plane equal to 3 - 10 ^o , and on it, guide ribs for the pulp are fixed in a spiral, curved in the direction opposite to the direction of rotation of the pipe.

The disadvantage of this device of the column diffusion apparatus is the increased heat loss through the housing of the diffusion apparatus and the absence of a waste heat utilizer from the premises of the beet processing department, because the heat radiated from the heated housing to the ambient air by the ventilation system is removed to the atmosphere.

Also known is the "Column diffusion apparatus for beet extraction" (A.S. No. 151897, C13B 10/00, publ. 04/20/2015, Bull. No. 11), including a housing divided by a vertical partition that does not reach the bottom into closed and open zones , a pulsator is installed on the cover of the closed zone, connected to a steam generator and a drive, and a liquid level sensor connected to each other through a control unit, in the upper half of the closed zone there is a pipe for loading raw materials, an open zone is connected to a pipe for unloading the extracted raw materials with a pipe for supplying water, characterized in that in the closed area there are inlet and outlet pipes connected to the heater, and the outlet pipes are also connected with the inlet of the loading pipe, on which the pipe for draining juice is located, and with the inlet pipes, and in the open area there is a pipe for supplying pulp press water. The closed zone of the diffusion apparatus housing contains at least one outlet and inlet pipes.

The disadvantage of this analogue of the diffusion apparatus for beet extraction is the significant heat loss through the heated, non-insulated housing of the column diffusion apparatus due to the lack of a heat exchanger in the beet processing room.

A device for an extraction plant is known (A.S. No. 1604834, publ. 07.11.90, Bull. No. 41), including a pre-treatment column with a vapor supply pipe installed in the technological sequence, an extraction column with an extractant supply pipe, an extractant separation unit and a squeezing screw for meal, an extractant recirculation system, the latter is made in the form of a cooler, a cleaning and drying unit and a condenser, and the water vapor recirculation system is connected to the pre-treatment column and is made in the form of a supply tank and a steam generator connected in series. In the extraction unit, the coil of the extractant separation unit is connected to the water vapor recirculation system.

The disadvantage of the described extraction plant is its purpose, since it is used in the process flow for processing only oil-containing raw materials. The use of this analogue for the extraction of other plant materials, for example, sugar beet chips is not possible.

Closest to the claimed technical solution in terms of technical essence and the achieved technical result is the equipment of the beet processing department with a column diffusion apparatus (see Grebenyuk S.M., Plaksin Yu.M., Malakhov N.N., Vinogradov K.I. Technological equipment for sugar factories. - M .: KolosS, 2007. - P. 128-130, Fig. 6.1). This equipment includes beet weighing devices, beet cutters, beet chip scalder, column diffusion apparatus and auxiliary equipment. The main equipment of the beet processing department contains a pulp head, a diffusion juice heater, a column diffusion apparatus, a water separator, liquid and steam heaters, sand traps, a collection of heated barometric water, a sulfitator, a collection, pumps, a scalder, a sump and a collection of pulp press water and a diffusion juice sand trap.

The disadvantages of this prototype are the increased heat costs caused by its loss through the vertical housing of the column diffusion apparatus, the scalder, the heaters for beet chips and diffusion juice, as well as the lack of devices for utilizing the heat generated from these heated apparatuses to create optimal microclimate conditions in the production room of the beet processing department. (according to "SanPiN 2.2.4.548-96, clause 2.2.4. Physical factors of the production environment. Hygienic requirements for the microclimate of industrial premises. Sanitary rules and regulations").

The technical objective of the claimed invention is to reduce the heat and energy consumption of the extraction process due to the return of the heat of the pulp press water and part of the recovered heat from the premises of the beet processing department.

The technical result of the claimed invention is the reduction of heat consumption for the diffusion process due to the return of part of the utilized heat from the obtained pulp water and from the heated air from the beet processing department.

The technical result is achieved by the fact that the claimed beet processing department with a column diffusion apparatus contains interconnected by pipelines a beet shaving head, a diffusion juice heater, a column diffusion apparatus, a water separator, a sand trap for pulp press water, a collection of barometric water, a sulfitator, a collection of sulphated barometric water, a pump for supplying barometric water, a pump for supplying fresh pulp press water, a pump for supplying settled pulp press water, a pump for supplying clarified diffusion juice, a pump for supplying juice mixture, a pump for pumping diffusion juice into a sand trap, a collection of pulp press water, a scalder, a sand trap for diffusion juice, while The column diffusion apparatus includes a vertical cylindrical body, inside which a pipe shaft is installed along the axis with a bladed transport device fixed in a spiral, which ensures the supply of a juice mixture from the bottom up, as well as a horizontal sieve fixed in the lower part of the column diffusion apparatus housing for separating the diffusion juice removed from the column diffusion apparatus, characterized in that the compartment is additionally equipped with an exhaust fan and a heat pump unit, consisting of a compressor, a liquid evaporator for extracting heat from the pulp press water removed from the water separator, an air evaporator for utilizing exhaust air from the beet processing compartment, a compressor, two condensers, one of which is designed for heating barometric water, and the other for heating pulp water before supplying heated barometric water and heated pulp press water to the column diffusion apparatus, two thermostatic valves to control the temperatures of barometric water and pulp press water before they enter the column diffusion apparatus, a pump for supplying sulphated barometric water into the liquid evaporator and a receiver designed to create a protective hydraulic seal between the liquid and air evaporators and condensers for heating barometric water and pulp water, also interconnected by pipelines.

The invention is illustrated by the following illustrations.

In FIG. 1 shows a diagram of a beet processing department with a column diffusion apparatus.

In FIG. 2 shows a section of the column diffusion apparatus.

In FIG. 3 shows a thermodynamic diagram of the pressure - specific enthalpy ( lg p - h) of the refrigerant for calculating the duty cycle of a heat pump installation.

The scheme of the beet processing department with a column diffusion apparatus contains a beet shaving head 1, a diffusion juice heater 2, a column diffusion apparatus 3, a water separator 4, a sand trap for pulp press water 5, a barometric water collector 6, a sulfitator 7, a sulphated barometric water collector 8, a pump for supplying barometric sulphated water 9, a pump for supplying pulp press water prepared for extraction 10, a pulp press water sump 11, a pump for supplying settled pulp press water 12 to the pulp press water sump 11, a collection of settled pulp press water freed from sand 13, a sand trap for diffusion juice 14, a pump 15 for supplying clarified sand-free diffusion juice into the scalder, pump 16 for supplying the juice mixture to the column diffusion apparatus and maintaining the required pressure in it, scalder 17, pump 18 for pumping diffusion juice from the scalder into the diffusion juice sand trap 19, exhaust fan 20, liquid evaporator 21, air evaporator 22, solenoid valve 23 of the barometric water preparation circuit, solenoid valve 24 of the pulp water preparation circuit, compressor 25, condenser 26 for maintaining the temperature of the barometric water, condenser 27 for maintaining the temperature of the pulp water, receiver 28 and pump 29 for supplying sulphated barometric water to liquid evaporator 21. In turn, the column diffusion apparatus 3 includes a vertical cylindrical body 30, inside which a pipe 31 is installed along the axis with a bladed transport device 32 fixed in a spiral, which ensures the supply of the juice mixture from the bottom upwards of the column diffusion apparatus, as well as a horizontal sieve 33 for separation of diffusion juice removed from the vertical cylindrical body 30 and fixed in the lower part of the body 30 of the column diffusion apparatus 3.

The claimed device works as follows. Beet chips are sent by a belt conveyor to the shaft of the scalder 17 for preheating with diffusion juice at a temperature of 72 °C. When the chips are heated, the diffusion juice is cooled to 47 ° C and is sent by pump 18 from the scalder 17 to the diffusion juice sand trap 19. Next, the diffusion juice enters the 1 mezgolovushka and after separation of the pulp in it is sent for further processing. The pulp separated in the head 1 is returned to the 17 scalder. In the 17 scalder, the beet chips are finally heated by the circulating juice, preheated by steam in the diffusion juice heater 2 from a temperature of 72 ° C to 85 ° C. Juice mixture with a temperature of 78 ° C from the scalder 17 by the pump 16 for supplying the juice mixture enters the column diffusion apparatus 3, in which it moves from bottom to top with the help of internal transport devices rotating with the pipe shaft 31 bladed transport devices 32. and due to pressure and pressure, Pressure and the pressure created by the pump for supplying the juice mixture is created by pump 16. Pulp press water is supplied to the upper part of the column diffusion apparatus 3 from condenser 27, in which a temperature of about 74 ° C is maintained. At the same time, barometric water is supplied by pump 9 to the upper part of the column diffusion apparatus 3 from condenser 26, in which a temperature of about 65 °C is maintained. Pulp press water prepared for extraction is supplied to the column diffusion apparatus 3 by pump 10 in the amount of 40% by weight of beet chips (m. St. page), and sulphated barometric water - by pump 9 in the amount of 60% m. St. page to the mass of beet chips The diffusion juice obtained as a result of countercurrent extraction of the chips is filtered through a horizontal sieve 33 of the column diffusion apparatus 3 and sent to the diffusion juice sand trap 14 to remove mineral sand impurities. Then the diffusion juice with a temperature of 72 ° C, discharged from the column diffusion apparatus 3 with a flow rate of 420% w.s. page to the mass of beet chips is divided into two streams. One flow with a flow rate of 120% w.m. page to the mass of beet chips with the help of a pump for supplying clarified diffusion juice 15 is fed into the scalder 17 for preheating beet chips. After the scalder 17, the diffusion juice is pumped out by the pump 18 into the diffusion juice grit trap 19 and sent through the head 1 for further processing. The second stream is circulating diffusion juice with a flow rate of 300% wt. page to the mass of beet chips is pumped 15 through the diffusion juice heater 2 to the column diffusion apparatus 3. Desugared beet chips (pulp) are fed by the conveyor to the water separator 4, and then to the pulp press department for pressing to obtain squeezed pulp and pulp press water. The pulp-pressing water enters the pulp head 5 to remove the pulp. Then, the pulped water purified in the pulp head 5 from the pulp head 5 is sent to the collector 13, from where it is pumped by the pump 12 into the sump 11 for final settling. Further, the settled pulp water is pumped by pump 10 to the liquid evaporator 21, in which low-grade heat is removed from the pulp press water due to the boiling of the refrigerant. Barometric water from the collector 8 is processed in the sulfitator 7 to achieve the required pH value and is sent to the collector of sulphated barometric water 8, from which it enters the condenser 26 for heating to the required temperature before being fed into the column diffusion apparatus 3. Heated air removed from the beet processing department by a fan 20 is injected into the air evaporator 22. From the liquid evaporator 21 and the air evaporator 22, the boiling refrigerant is sent to the compressor 25, from which the compressed vapors are discharged into two condensers: through the condenser 26 - barometric water, and through the condenser 27 - pulp water. The extractants heated in this way in condensers 26 and 27 to the required temperature - sulphated barometric water and bagasse water are fed into the upper part of the column diffusion apparatus 3 for the extraction of sugar beet chips. To prevent microbiological decomposition of sugar and maintain the required acidity of water, a formalin solution is supplied to the scalder 17 and column diffusion apparatus 3.

The low-temperature heat emitted from the premises of the beet processing department from the heated body of the column diffusion apparatus 3, from the beet chip scalder and the diffusion juice heater 2, as well as from the pulp press water in the inventive device is utilized in a vapor compression heat pump installation, including a liquid evaporator 21, an air evaporator 22, thermostatic valves 23 and 24, compressor 25, condensers 26 and 27, in which the optimal corresponding temperatures of barometric water of 65°C and pulp water of 74°C are achieved, which are necessary for extraction in column diffusion apparatus 3. To create a protective water seal between the evaporators and condensers, a receiver is installed 28. The supply of sulphated barometric water to the liquid evaporator is carried out by pump 29.

We will explain the operation of the described heat pump installation with an example. The refrigerant, for example, R401a, boils at a temperature of 5°C and absorbs the low-grade heat of the pulp press water obtained during the pressing of the pulp. An additional source of low-grade heat is air from heated thermal devices (diffusion juice heater 2 and scalder 17) and column diffusion apparatus 3. Air is taken from the beet processing department by a fan 20 with a temperature of at least 28-30 ° C. The vaporous refrigerant from the liquid evaporator 21, where pulp press water enters, is fed into the compressor 25, in which the refrigerant vapor is compressed with an increase in pressure up to 2.8 MPa and a vapor temperature up to 85°C. Similarly, the refrigerant from the air evaporator 22, which extracts heat from the beet processing room, is also sent to the compressor 25. The high-temperature refrigerant obtained in the compressor 25 enters the condensers 26 and 27 to obtain the appropriate extractant temperatures: pulp water 74°C and barometric water 65°C. To create a protective water seal between the liquid evaporator 21, the air evaporator 22 and the corresponding condensers of the heat pump installation 27 and 26, as well as to separate the oil from the air, the receiver 28 serves. barometric water 23 and pulp water 24.

The claimed invention can be illustrated by the following proposed example. The productivity of the column diffusion apparatus Q = 4.0 thousand tons of beets / day

To calculate the heat costs for the operating conditions of the prototype, it is necessary to perform a material and thermal calculation of the apparatus.

The equation of the material balance of the apparatus has the form (1):

where G _str - chip consumption;

G _W - pulp output;

G _in - the amount of feed water;

G _ds - selection of diffusion juice.

According to accepted technological standards (Sapronov A.R. Technology of sugar production. - M.: Kolos, 1999. 495 p.)

Then, from equation (1), the consumption of feed water (extractant), taking into account relations (2) and (3), will be:

Checking the correctness of the balance is carried out according to equation 1:

Therefore, the balance is correct.

To perform a thermal calculation, we compose the heat balance equation (5):

WhereΣQ _etc - the amount of heat flows entering the apparatus;

ΣQ _wow is the sum of outgoing heat fluxes.

where Q _str is the heat brought by the chips into the apparatus;

Q _in - the heat brought by the feed water.

where _cstr is the heat capacity of the chips, 3768 J/kg K is taken;

t _str - chip temperature, assumed 60 ^◦ C.

WhereQ _V - feed water consumption (barometric - 60% by weight of water, or

G _bw \u003d 29.16 kg / s) and pulp water - 40% by weight of water, or

G _lw \u003d 19.44 kg / s)

с _в - heat capacity of feed water, 4200 J/kg K;

t _in - feed water temperature, incl. barometric water 65 ^◦ C and

pulp water 74 ^◦ C.

where Q _w is the heat carried away with the pulp;

Q _ds - heat carried away with diffusion juice;

Q _p - heat loss through the outer enclosures of the apparatus.

where c _w is the heat capacity of the pulp, 4190 J/kg K is taken;

t _W - the temperature of the pulp, taken 65°C.

where c _ds is the heat capacity of the diffusion juice, 3768 J/kg K is taken;

t _in - the temperature of the diffusion juice, 72 ^◦ C is taken.

Determination of heat losses

In the case of direct heating of barometric water, the heat costs will be

For direct heating of pulp water

Total heat costs for heating the extractant

In the case of using a heat pump unit to heat the extractant, the total heat costs are the sum of the amount of heat(Q _O ), taken from the air of the separation room and the heat of the obtained pulp water and the heat equivalent to the expended work of the compressor (N _l )

To calculate the heat pump adopted:

thermal load (according to formula (17)) Q _t \u003d 9.92 MJ / s;

the average temperature of the low-potential coolant at the inlet to the heat pump t _n1 =27 °C;

temperature of the low-grade coolant after the heat pump t _n2 =14 °C;

the average air temperature in the beet processing department during the sugar beet processing season t ₀ = 30 ° C;

temperature drops at the outlet of the heat exchangers in the evaporator ∆t _app , condenser ∆t _k is assumed to be 3 ... 5 ° С

Refrigerant evaporation temperature:

t _And = t _h2 – ∆t _Spanish = 14 - 4 = 10 ° (19)

Refrigerant condensation temperature t _to :

t _k \u003d t _v2 + ∆t _k \u003d 74 + 3 \u003d 77 ° С (20)

To build a thermodynamic cycle of operation of a heat pump installation, we use lg p - h - a diagram (Fig. 1), on which:

- point 1' characterizes the state of the refrigerant in the evaporator;

- process (1'-1) - overheating of the refrigerant in the evaporator;

- point 1 characterizes the state of the refrigerant before _{compression ;}

- process (1-2) - compression of the refrigerant in the compressor;

- point 2 characterizes the state of the refrigerant after its isentropic compression. Point 2 is located on the continuation of the Pk isobar corresponding to the condensation pressure at temperature tk and the isentrope drawn from point 1;

- process (2-3) - isothermal condensation of the refrigerant in the condenser and heat transfer to a high-potential coolant;

- point 3 characterizes the state of the refrigerant after the condenser, taking into account heat losses. The position of point 3 is determined by the intersection of the isobar Pk and the isoenthalpe h ₃ ;

- process 3-4 - reversible expansion of the refrigerant in the expansion valve;

- point 4 characterizes the state of the refrigerant at the outlet of the condenser. The position of point 4 is determined by the intersection of the Pk isobar and the boundary curve x = 0 (in this case, the pressure drop during condensation is neglected due to its small value).

- process 4-1 - isothermal evaporation of the refrigerant in the evaporator due to the heat taken from the cold heat carrier.

The obtained values of the operating points of the thermodynamic cycle are summarized in Table 1.

Table 1 - Calculated parameters of the thermodynamic cycle of the heat pump

installations

No. R , Bar t , ̊ C h , kJ/kg v 1 0.4 10 420 0.060 1' 0.4 13 415 0.056 2 2.8 105 477 0.0095 3 2.8 80 315 4 0.4 10 315

The work of compression in the compressor

l _compress \u003d h ₂ - h ₁ \u003d 477 - 420 \u003d 57.0 kJ / kg (21)

Specific heat load in the condenser

q _k \u003d h ₂ - h ₃ \u003d 477 - 315 \u003d 162.0 kJ / kg (22)

equal to the heat load of the heat pump unit

q _k \u003d q ₀ \ u003d 162 kJ / kg .

The mass flow rate of the refrigerant G _ha , kg / s, is determined by the heat load of the installation Q ₀ , equal to the amount of heat received by the hot coolant:

G _ha \u003d Q ₀ / q ₀ \u003d 9.92 / 162.0 \u003d 61.2 kg / s (23)

Theoretical compressor power:

N _l \u003d G _xa × l _com = 61.2 × 57 \u003d 3.5 MW (24)

Total heat load in the condenser

Q _o \u003d G _xa q _k \u003d 61.2 162 \u003d 9.914 MW (25)

It was obtained by calculation that when waste heat is utilized for heating the extractant, the value of heat loss according to the balance equation (equation (17)) is covered by the load on the capacitors. And the calculated capacity of the compressor (equation (24)) of the heat pump unit is about 30% of the cost of heating the extractant.

For the example under consideration, the heat conversion coefficient of the heat pump installation µ is

µ \u003d q ₀ / l _szh \u003d 162 / 57 \u003d 2.84,

those. for 1 kW of electrical energy consumed, the heat pump produces 2.84 kW of thermal energy. Saving energy resources for the preparation of the extractant reaches 70%.

In other words, in the claimed invention, the heat losses of the extraction process are not lost irretrievably, but are utilized in a vapor-compression heat pump unit included in the scheme of the beet processing department with a column diffusion apparatus, which allows it to be used to heat barometric and pulp-pressed water to the required temperatures and thereby exclude from circuits high-temperature steam and liquid heaters, which generally provides a significant reduction in the heat load in the beet processing department during the extraction of sugar in a column diffusion apparatus.

Thus, the claimed invention allows:

- reduce the heat costs for the diffusion process by utilizing the low-temperature heat of the pulp-pressing water and returning part of the utilized heat from the heated housings of the heaters and the column diffusion apparatus installed in the beet processing department;

- to regulate the temperature of the supply of barometric and pulp water to the column diffusion apparatus, depending on the quality of the processed sugar beet;

- reduce the air temperature in the beet processing department to the standard microclimate in the production room of the beet processing department by removing heated air from the beet processing department.

Claims (1)

A beet processing department with a column diffusion apparatus, containing interconnected by pipelines a beet shavings head, a diffusion juice heater, a column diffusion apparatus, a water separator, a sand trap for pulp press water, a barometric water collector, a sulfitator, a collector of sulphated barometric water, a pump for supplying barometric water, a pump for supplying fresh pulp press water, a pump for supplying settled pulp press water, a pump for supplying clarified diffusion juice, a pump for supplying a juice mixture, a pump for pumping diffusion juice into a sand trap, a pulp press water collector, a scalder, a diffusion juice sand trap, while the column diffusion apparatus includes a vertical cylindrical a housing inside which a pipe is installed along the axis with a bladed transport device fixed in a spiral, providing the supply of a juice mixture from the bottom up, as well as a horizontal sieve fixed in the lower part of the housing of the column diffusion apparatus for separating the diffusion juice removed from the column diffusion apparatus, characterized in that the compartment is additionally equipped with an exhaust fan and a heat pump unit, consisting of a compressor, a liquid evaporator for extracting heat from the pulp-pressing water removed from the water separator, an air evaporator for utilizing exhaust air from the beet processing compartment, a compressor, two condensers, one of which is designed to heat barometric water, and the other - for heating pulp water before supplying heated barometric water and heated pulp press water to the column diffusion apparatus, two thermostatic valves to control the temperatures of barometric water and pulp press water before they enter the column diffusion apparatus, a pump for supplying sulphated barometric water to the liquid evaporator and a receiver designed to create a protective water seal between liquid and air evaporators and condensers for heating barometric water and pulp water, also interconnected by pipelines.

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