RU6717U1 - MULTI-STAGE EVAPORATION INSTALLATION - Google Patents

Abstract

A multi-stage evaporation plant containing a circulation circuit of a solution with natural chalk seed crystals, including evaporators, a settling tank, pipelines and nozzles, the first evaporator being equipped with an inlet pipe through regenerative heaters of the initial scale-forming solution, characterized in that the installation is equipped with a second circulation circuit of the solution with sulfate seed crystals calcium, including evaporators, sump, pipelines and nozzles, and the nozzle of the clarified solution of the primary circuit tank is connected by a pipeline to the first evaporator of the second circuit, the secondary tank of the second circuit is equipped with a suspension pipe for seed crystals of calcium sulfate, connected by a pipe to the first evaporator of the second circuit, the secondary steam pipe of the last evaporator of the primary circuit is connected by a pipe to the pipe annulus of the first evaporator of the second circuit crystallizer evaporators, classifier, sedimentation tank, centrifuges for complete processing concentrated solution for commercial salt products, the first evaporator-crystallizer, classifier, sump, pipelines and nozzles combined in the third circulation circuit of the solution with seed crystals of calcium sulfate, the sump of the second circuit equipped with nozzles of a clarified solution and suspension of seed crystals of calcium sulfate, connected by pipelines to the first the third circuit crystallizer evaporator, the third circuit sump is equipped with nozzles of clarified solution and gravy

Description

STEEP EVAPORATING INSTALLATION

The utility model relates to evaporation technology, namely, to multi-stage thermal evaporation plants, and can be used for the complete processing of scale-forming natural and wastewater into distillate and salt products without salt discharges by closed technology in the energy, metallurgical, chemical and other industries.

It is especially advisable to use it in heat supply systems of large boiler houses and 1EC.

Environmental protection is currently a very urgent task. Meanwhile, the volume of wastewater, often discharged into open water, is growing like an avalanche every year. The complete processing of such waters would make it possible to get rid of salt discharges, to obtain salable salt products, as well as distillate, suitable for the preparation of drinking water and make-up water for steam boilers, which is an acute shortage in many industries and regions.

However, the solution to this problem is associated with serious difficulties | 1 caused by the presence of scale-forming components in most discharged effluents, which for thermal evaporation plants poses a risk of scale on tubular heating surfaces, deterioration of heat transfer, and a slight decrease in their efficiency.

Thirty-two-year experience of the applicant operating a large complex for desalination of the Caspian Sea water in Aktau (Kazakhstan) showed that with the help of seed crystals of natural chalk (calcium carbonate) sulfate scale can be avoided only with a small degree of concentration of scale-forming water, to the so-called sulfate barrier, (2 -3.5 times). With a greater degree of concentration necessary for complete water treatment, begins to stand out / J //

U1D 1 / 2b, S02P 1/04

pouring calcium sulphate from the solution and the formation of hard-washed sulphate scale on the heating surfaces of evaporators.

Known multi-stage desalination plant with the prevention of carbonate scale by recirculation of seed crystals of natural chalk (Water Supply and Sanitary Engineering, 1973, No. 7, p. 27), containing 34 steps of instant boiling, a head heater, a condenser and a sump (clarifier), combined into a common circulation circuit.

Seed - finely ground natural chalk is introduced into the system once at startup and then recycled by a centrifugal pump and clarifier through all 34 steps.

A disadvantage of the known installation is the inability to concentrate the initial solution by more than 2-3.5 times due to the formation of hard-to-wash sulphate scale, which cannot be prevented with the use of seed crystals of natural chalk.

Another disadvantage is the discharge of brine into an open reservoir, as well as the high cost of electric energy for circulating the solution in instant boilers. In addition, the operating experience of the installation showed a lack of effectiveness in preventing carbonaceous scale in instant boilers.

Closest to the claimed one is the S-case desalination plant, carried out according to the direct-flow multi-stage evaporation scheme (Water Supply and Sanitary Engineering Journal, 1973, No. 7, p. 30), containing a circulation circuit of the solution with natural chalk crystals, including evaporators, a settling tank, a condenser, pipelines and nozzles, the first evaporator being provided with an input nozzle through regenerative heaters of the initial scale-forming solution (sea water). The source water from the sea intake enters the condenser, where it is heated to 3 ° C, part of it is discharged, and the part necessary to supply it is fed through the deaerator and the regenerative heater system to the first evaporator. To prevent carbonate scale, seed crystals are introduced into the solution. The seed - finely ground natural chalk - is introduced into the system once at startup and then recycled using a clarifier (sump) and a centrifugal pump. The clarified brine is discharged into the sea, and the condensed seed suspension is returned to the installation. The heating steam pipe from an external source is connected to the pipe end of the annulus only of the first evaporator. The remaining evaporators are heated by the secondary evaporators of the previous stages.

This installation is selected as a prototype. The disadvantage of the prototype is the inability to concentrate the source water with one circulation loop more than 2-3.5 times, which is due to two reasons: firstly, the danger of separation of insoluble limescale calcium sulfate, which cannot be prevented in the same loop recirculation of seed crystals of natural chalk; secondly, because for reliable pumping of the seed suspension from the sump by the pump it is necessary, as shown by operating experience, that the concentration of the seed at the outlet of the recirculation loop does not exceed 70 80 g / kg

Therefore, if in order to reliably prevent scale in the first evaporator of the circuit, the seed concentration is 15-g) g / kg, the maximum possible degree of water concentration in the recirculation loop will be on average no more than 5, and it is usually necessary to concentrate 10-15 or more times. Another disadvantage of the prototype is the discharge of brine into the sea or other body of water, which is a violation of environmental requirements for the protection of the environment. In addition, a small degree of concentration of the source water makes it economically impractical to extract valuable products from it.

deep concentration of the source water necessary for the complete economically feasible processing of concentrated brine into salable salt products without salt discharges into open water bodies.

The main objective of the utility model is the creation of a multi-stage evaporative installation for deep concentration of the initial salt-containing water with its full conversion to salable salt products without salt discharges into the environment, as well as increasing the reliability of the installation while reducing energy and operating costs.

An additional task is to increase the efficiency and reliability of preventing the scaling of carbonate and calcium sulfate.

The main and additional tasks are achieved by the fact that:

1. The installation is equipped with a second circulation circuit of the solution with seed crystals of calcium sulfate, including evaporators, sump, pipelines and pipes, and the sump of the first circuit is equipped with a pipe of the clarified solution connected by a pipe to the first evaporator of the second circulation circuit;

The sump of the second circuit is equipped with a pipe suspension of seed crystals of calcium sulfate, connected by a pipe to the first evaporator of the second circuit, a pipe of the secondary steam of the last evaporator of the first circuit is connected by a pipe to the pipe of the annular space of the first evaporator of the second circuit.

2. The installation is equipped with evaporators — crystallizers, a classifier, a settler, and other equipment for processing the concentrated solution into salable products, the first evaporator-crystallizer, classifier, settler, pipelines, and nozzles combined in a third circulation circuit of the solution with seed crystals of calcium sulfate, sedimentation tank of the second

the circuit is equipped with nozzles for the clarified solution and suspension of seed crystals, calcium sulfate is connected by pipelines with the first crystallization evaporator of the third circulation circuit, and the sump of the third circuit is equipped with nozzles of the clarified solution and suspension of calcium sulfate crystals, connected by pipelines to the last and first evaporators, respectively crystallizers.

Comparison of ayuyuyemy technical solutions not only with the prototype, but also with other technical solutions in this technical field did not allow to reveal the indicated set of features in them. Thus, the claimed technical solution is not known from the prior art and meets the criteria of the novelty utility model.

The specified set of features is a set of essential features, since it is sufficient to achieve a technical result provided by a useful model, which erupts in the possibility of preventing sulphate scale, making it possible to concentrate the initial salt-containing water and completely process it into commercial salt products without salt discharges into the environment, and increase the reliability of the declared multi-stage evaporator installation, reducing energy costs due to multi-layer the proper use of heat in evaporators and crystallizer evaporators. Comparison of the analysis with the prototype shows that the claimed installation is characterized by the presence of signs that are distinct from the prototype and sufficient in all cases to which the requested amount of legal protection applies.

The claimed combination of essential features, due to their mutual influence on the achievement of the above technical result of the proposed technical solution, provides high efficiency of the installation to achieve reliable prevention of scale of calcium carbonate and calcium sulfate, deep concentration

source water, which allows organizing economically feasible extraction of salable salt products from a concentrated solution, avoiding salt discharges into the environment, increasing the efficiency of the installation by connecting the secondary vapor pipe of the last evaporator of the primary circuit with the pipe of the annular space of the first evaporator of the second circulation circuit, and also solves the technical the contradiction of the known technical solutions, which consists in the fact that according to the connection scheme of the apparatus it is impossible to deeply concentrate the initial salt-containing solution and avoid calcium sulfate scale deposits on the heating surfaces.

The installations known from the prior art, both in aggregate and separately, do not solve the task and the above contradiction.

The proposed set of essential features does not follow explicitly from the prior art, which is confirmed by the presence of distinctive features in this combination.

Causal relationships between the set of essential features of the claimed technical solution and the achieved technical result are as follows.

Providing the installation with a second circulation circuit of the solution with seed crystals of calcium sulfate, including evaporators, a sump, pipelines and pipes, and equipping the sump of the first circuit with a clarified solution pipe connected by a pipe to the second circulation circuit, prevents sulfate scale and the possibility of increasing the concentration of the initial solution, and also provides conditions for reliable pumping of the suspension of seed crystals from the sump.

Beyond the top of the boiled aonarate — crystallizer, classifier, Schick pipelines and outlet pipes into the third circulating HHft solution loop with seeding calcium sulfate crystals, equipped with a trap of the second catarrh circuit of the clarified solution and a suspension of calcium sulfate seed crystals, and a connected loop from the pipeline the third circuit - the nozzles of the clarified solution f and suspension

crystals of calcium sulfate, connected by pipelines, respectively, to the last and first evaporated apparatus - crystallizers, provides the possibility of complete processing of the initial solution into salable salt products without salt discharges into the environment.

Ck) the union of the pipe of the second pass of the last evaporation of the percotta with pltcom inter-space. The steam water supply of the evaporator of the second circuit provides a reduction in the consumption of heating steam from an external source and an increase in the efficiency of the claimed installation.

The figure attached to the application shows a diagram of the inventive installation. Pictured are seven evaporators and two evaporative unit crystallizers, but the number of both evaporators and crystallizers may be larger.

The following flow conventions are accepted here: steam

they’ve got t sh - raSTyur

 ,. Distillate, demineralized water

.-g - salt products

-h-h-h- - seed crystal suspension

 - suspension of seed crystals

primary circuit

snarche apparatus krisgahzhiaatrr, khassi | 1ka оr 16 prices 17-19, tr: water supply 1: trevsbRo var from the main source I), cone; heating steam of 21 "secondary steam 22,23, source water 24, input of source water 25 into evaporator I , a concentrated solution with seed crystals of natural chalk 26, a clarified solution of natural chalk 28, a suspension of seed crystals of natural chalk 28, a concentrated solution with seed crystals of sulfate 29, a clarified solution of the second circuit 30, its defleination solution of the second HoiiTypa-i conc a grouted solution with seed crystals of calcium sulfate and salable 3lf saline products, a solution with a saline product separated into a classifier of salting crystals 32, clarified solution 33 from the settler II of the third solution circuit — salt product 34, crystalline saline products from centrifuges 35-37, suspensions of seed crystals second 38 and third circuits 39, the output of the distillate 40 and demineralized water 41 from the installation of the suspension of seed crystals 42 from the classifier 16 in the sump II, pipes.-clarified solution 43 from the sump 9 of the first circuit, clarified solution 44 from the sump 10 of the second circuit, clarified solution 45 I suspension of seed crystals of calcium sulfate 46 from the sump of the third circuit II, secondary steam 47. ", evaporator 4, annulus 48 of evaporator 5, input water 49 to the evaporator X, the annulus 50 of the evaporator I and the evaporator apparatus - crystallizer MA of the suspension of herbal crystals of stool sulfate | o1 from the sump ID of the secondary circuit.

Evaporators sump 9, pipelines 25,26,40, branch pipe 49

make up the first circulation circuit of the solution with seed crystals of natural chalk.

sedimentation tank II at the trunk wire 31.42.39 and water: 7bsc 46 obvdiyein into the third circuit of the solution with ethereal crystals with: carbonate and suspensions of seed crystals of potassium sulfate.

Installation works as follows.

The heating steam pipelines from an external source are connected to the branch tubes 50 7, respectively, of the first evaporator of the first circuit and of the first external crystallizer apparatus. The remaining evaporators are regenerative heaters & the next hedge apparatus - crystalline / 5 aator are heated by the second pair of the previous apparatuses, for which the pipe by piping from the pipe-connecting space of the first evaporator 5 of the second circuit Condensate of dead steam from the first evaporator through pipelines 21 returns to an external source.

The source of natural or waste water through a pipe 24 is fed through heat transfer pipes of regenerative heaters to the first evaporator of the First circuit. .

Seed crystals are introduced into the system once at start-up and then recycled by sedimentation tanks and centrifugal pumps

(not shown in the figure), moreover, seed crystals of fine-grained natural chalk are introduced into sump 9, calcium sulphate seeds are introduced into sumps 10 and II

The success of the seed crystals of natural chalk of the sump 9 is returned via line 28 to the first circuit evaporator I, and the clarified solution from the pipe 43 of the sump 9 is introduced for further concentration through the pipe 27 to the first evaporator 5 of the second circuit.

The thickened suspension of seed crystals of calcium sulfate from the pipe W of the sump 10 is supplied through pipelines 36 and 39 to the second and third circulating circuits.

in

& N

a thief with seed hryahahlani natural honey schchdduet in Vervon kont: re on tr: boarovoda || 25,26 and 2В eroheochemix pipes and evaporators U) oTetoflBHKl a for the prevention of limescale calcium sulfate solution with seed crystals with: calcareous alkali circulating in the second circuit: through piping 27, 38 through the heat exchange condenser of evaporators 5-7 and the third circuit: re — through the pipes 31, 42, 39 through the heat exchange pipes of the first evaporator-cristalizer 14, classifier 16 and settler II.

The solution clarified in the settling tank 10 from the pipe 44 is fed through a pipeline 30 for the final concentration and crystallization of the first commercial product (ti & ne of all common salt} or sodium sulfate} into the first evaporator-crystallizer 14 of which a solution 31 is formed through the pipeline 31 with seed crystals and crystals evaporation of the first commercial product is fed to the classifier 16, in which smaller seed crystals from larger crystals of commercial salt are separated from the solution in an ascending stream The solution with the seed crystals through line 42 enters sump II.

A part of the suspension of mash 1 | nyg sulfate crystals from settler II is fed to a centrifuge 18, from which a new

salable product ZbSv in the form of crystalline gypsum) With uz & tv, the suspension of seed crystals from the nozzle returns to the first boil |

the solution from the pipe 45 through the pipe 33 is supplied to the boiled appa / "rat-crystallizator for crystallization of other salable products

The thickened suspension of the first salable salt product from the classifier 16 is fed through a pipe 32 to a centrifuge 17, from which the first crystalline salt product 35 is supplied. After the separation of salts in the centrifuges 17 and 18, the mother liquor is fed to the last evaporator-crystallizer 15 for processing.

6

The superstitious superstition of the co-product and the adjoining invariant apparatus 15 is performed on a centrifuge 19, in which the last Kzletahliid sokheoroduht 37 and the solution-schhearoduct 34 are most popular.

Evaporators and vicharshe avarate crystal BHiaatorn is equipped with highly efficient napocesapaipoHHiaiK devices w

rnnoro steam 40 from yaofreyitvdey and demineralized water of the digestion apparatus - crystallizers 41 can be used for rI1CH) of drinking water supply and power supply of steam boilers medium and high |

Thus, in the proposed installation, natural or wastewater can be completely recycled to distillate and salt products without salt discharges into the environment using a closed technology.

The inventive utility model can be widely used in the energy, metallurgical, chemical, biotechnological, electronic and other industries.

It is especially advisable to use it in the heat supply systems of large boiler houses, TPPs and 1ES, where there is always a need for wastewater treatment and high quality distillate is always needed to power medium and high pressure steam boilers.

Therefore, the claimed utility model meets the criteria mentally {

Using the proposed installation allows, in comparison with the prototype, to obtain the following technical and economic advantages:

carry out deep concentration of the source scale-forming natural or wastewater while reliably preventing scale of carbonate and calcium sulfate;

hazardous discharges in oh | Harvesting: a medium due to the processing of the source water into distillate and soderoduct product

The claimed installation is ecologically safe, since the vag. demineralized water and a salt pro- duction distillate from it: they are used repeatedly in industry.

Claims (1)

A multi-stage evaporation plant containing a circulation circuit of a solution with natural chalk seed crystals, including evaporators, a settling tank, pipelines and nozzles, the first evaporator being equipped with an inlet pipe through regenerative heaters of the initial scale-forming solution, characterized in that the installation is equipped with a second circulation circuit of the solution with sulfate seed crystals calcium, including evaporators, sump, pipelines and nozzles, and the nozzle of the clarified solution of the primary circuit tank is connected by a pipeline to the first evaporator of the second circuit, the secondary tank of the second circuit is equipped with a suspension pipe for seed crystals of calcium sulfate, connected by a pipe to the first evaporator of the second circuit, the secondary steam pipe of the last evaporator of the primary circuit is connected by a pipe to the pipe annulus of the first evaporator of the second circuit crystallizer evaporators, classifier, sedimentation tank, centrifuges for complete processing concentrated solution for commercial salt products, the first evaporator-crystallizer, classifier, sump, pipelines and nozzles combined in the third circulation circuit of the solution with seed crystals of calcium sulfate, the sump of the second circuit equipped with nozzles of a clarified solution and suspension of seed crystals of calcium sulfate, connected by pipelines to the first the third circuit crystallizer evaporator, the third circuit sump is equipped with nozzles of clarified solution and gravy the ratio of seed crystals of calcium sulfate, connected by pipelines, respectively, to the last and first evaporator-crystallizer.