RU2706617C2 - Makeup water preparation system for heat generating plants of thermal power plants or industrial boiler rooms - Google Patents

Abstract

FIELD: water supply; sewerage.

SUBSTANCE: invention can be used in water treatment. Makeup water preparation system for heat generating plants includes preliminary treatment plant 10 with mechanical filter 13 with filtration layer 131 and reverse osmosis desalination unit 70 with concentrate collection tank 72. Line 200 for removal of concentrate from concentrate collection tank 72 is connected to lower part of mechanical filter 13 for use of concentrate of reverse-osmosis desalination plant 70 as washing medium for loosening regeneration of filtration layer 131. To lower part of mechanical filter 13 there additionally connected is discharge line 300 to concentrate collection tank 72 of excess volume of clean flushing medium after completion of filtration layer regeneration process 131. Ratio of volume of concentrate collection tank 72 to volume of filtering layer 131 makes 15–20. If prefilter 10 comprises, at least, two parallel mechanical filters 13 with filtration layer 131, their intermittent regeneration is performed in turn.

EFFECT: disclosed invention provides the possibility of using the makeup water preparation process wastes as a washing medium for filtering layer regeneration.

1 cl, 1 dwg, 2 tbl

Description

Technical field

The invention relates to the field of water treatment and can be used for the preparation of make-up water for heat-generating plants (steam and hot water boilers, heating water heaters) of thermal power plants, industrial boiler houses and other industrial facilities.

State of the art

Known adopted as a prototype of the patented invention, a system for the preparation of make-up water for heat-generating installations of thermal power plants or industrial boiler houses, containing in series:

the initial water pre-treatment unit, which includes at least two parallel-connected mechanical filters with a filter layer.

and a reverse osmosis desalination unit with a concentrate collection tank and a concentrate drain line attached to the bottom of the indicated tank, (Experience in the development of new water treatment technologies at TPPs / Larin B.M. et al. Ivanovo State Power Engineering University // Thermal Power Engineering, 2010, No. 8, S. 8-13, Fig. 4. [1]).

At the same time, the pre-treatment plant, as a rule, contains at least two mechanical filters to enable the periodic shutdown of one of them to regenerate the filter layer without stopping the water purification process. Each mechanical filter in such an installation is usually equipped with an independent unit for the indicated regeneration of the filter layer after it is contaminated during operation (RU 2000116944, B01D 24/48, 2000 [2]). Regeneration is always carried out by loosening the washing of the filter layer with a washing medium, which is usually used clarified water after clarifiers or purified water from working mechanical filters.

The disadvantage of this technical solution in relation to [1] is the need for costs for the regeneration of the filter layer of a mechanical filter, associated with a high consumption of relatively expensive clarified or purified natural water on mechanical filters.

Disclosure of invention

The objective of the patented invention is to reduce the cost of regeneration of the filter layer of the mechanical filter of the pre-treatment plant of the makeup water treatment system, and the technical result is the possibility of using the waste of the makeup water preparation process itself as a washing medium for the regeneration of the filter layer of the specified filter.

The solution of this problem by achieving the specified technical result is ensured by the fact that in the system for the preparation of make-up water for heat-generating plants of thermal power plants or industrial boiler houses, containing in series:

initial water pre-treatment unit, which includes mechanical filters with a filter layer;

a reverse osmosis desalination plant with a concentrate collecting tank and a concentrate discharge line connected to the lower part of the indicated tank, according to the patented invention:

the concentrate discharge line from the corresponding tank of the reverse osmosis desalination plant is connected to the lower part of each of these mechanical filters to use the specified concentrate as a washing medium during loosening regeneration of the filter layer as it becomes contaminated in each of these filters,

and to the bottom of each mechanical filter is additionally connected a discharge line to the concentrate tank of an excess volume of clean washing medium after completion of the process of loosening regeneration of the filter layer:

In this case, the ratio of the volume of the concentrate collection tank to the volume of the filter layer of one mechanical filter is preferably 15-20.

The causal relationship between the totality of distinctive features and the specified technical result of the patented invention is as follows:

connecting the concentrate discharge line from the corresponding tank of the reverse osmosis desalination plant to the lower part of each of these mechanical filters ensures the use of the concentrate from the reverse osmosis desalination plant, which is a waste of the make-up water preparation process (at the desalination stage) as the washing medium of the filter layer of these filters;

connecting to the lower part of each mechanical filter a discharge line of an excess volume of a clean washing medium to a concentrate tank after completing the process of loosening regeneration of the filter layer eliminates the return to the osmosis unit of excess (remaining in the mechanical filter) concentrate with a salt content 4-5 times higher than in source water and accordingly prevents deterioration of permeate quality.

The indicated preferred ratio between the volumes of the concentrate collection tank and the filter layer of the mechanical filter allows you to select the optimal volume value of the specified concentrate collection tank.

Brief Description of the Drawing

The drawing schematically shows a system for the preparation of make-up water for one of the possible embodiments of the patented invention.

Legend

BK - a tank of concentrate;

BOV - a tank of clarified water;

BP - a tank of demineralized water - permeate;

M - mechanical filter;

O - clarifier;

PC - industrial boiler room;

TSU - heat generating installation;

TPP - thermal power station;

UOO - installation of reverse osmosis desalination;

UPR - pre-treatment unit.

List of drawing items

10 - UPR; 11 - O; 12 - BOV; 13 - M; 131 - filter layer; 20 - supply line of source water; 30 - drainage line of clarified water; 40 - line discharge into the sewer settled sediment; 50 - line for supplying clarified water to M 13; 60 - feed line in the UO of clarified water purified in a mechanical filter; 70 - DOE; 71 - PSU; 72 - BC; 80 - line feed permeate to BP; 90 - line for the discharge of concentrate from UO to BC; 100 - feed line of permeate as make-up water to heat generating plants; 200 - concentrate supply line from BC 72 to filter M13; 300 — discharge line of the excess volume of the clean washing medium from Ml3 to BC 72; 400 - line discharge into the sewer contaminated flushing medium from M13.

The implementation of the invention

The make-up water preparation system for heat generating plants (TPU) not shown in the drawing of thermal power plants (TPP) or industrial boiler rooms (PC) according to the patented invention comprises a preliminary treatment unit (UPR) 10, which includes: a clarifier (O) 11, a clarified water tank (BWA) 12 and in this example, to simplify the drawing, one mechanical filter (M) 13 with a filter layer 131. A feed water supply line 20 is connected to clarifier O 11. Lines 30 and 40 are respectively used to supply clarified water to BOW 12 and for discharge the sewage system settled suspension. The clarified water drain line 50 connects the BOV 12 to the mechanical filter M 13, the filter M 13 with the filter layer 131 is connected by a line 60 to the input part of the reverse osmosis desalination plant (UOE) 70. From which lines 80 and 90, connecting the demineralized water tank, respectively, leave (BP) 71 and a concentrate tank (BC) 72. Line 100 serves to supply permeate from BP 71 as makeup water to boilers of a TPP or an industrial boiler room. Connected to the bottom of the BC 72, the concentrate discharge line 200 at the other end is connected to the bottom of the filter M 13 to use the concentrate as a washing medium for loosening regeneration of the filter layer 131 of this filter. The possibility of using UOO 70 concentrate as a washing medium is related to the fact that it is pure water, but with an increased salt content, which does not interfere with its function of washing the filter layer 131 from mechanical impurities. To the lower part of M 13 is additionally connected a discharge line 300 in BK 72 of the excess volume of the clean washing medium after the regeneration of the filter layer is completed. And the line 400, attached to the upper part of the filter M 13, is designed to discharge into the sewer a contaminated flushing medium.

The work of the invention is as follows:

The feed water through line 20 enters the pre-treatment unit UPO 10, where first the clarifier O 11 passes, in which it is treated with reagents to precipitate suspended and colloidal impurities. The clarified water through line 30 is collected in the clarified water tank BOW 12, from where it is supplied through line 50 to a mechanical filter M 13. And the precipitated mixture from O 11 is discharged through line 40 to the sewer. The clarified water purified in the filter layer 131 of the mechanical filter M 13 is fed through line 60 to the UOO 70 reverse osmosis desalination plant. After the UOO 70, demineralized water — permeate — is fed through line 80 to the BP 71 permeate tank, from where it is sent as feed to line 100 water to heat generating plants of thermal power plants or industrial boiler rooms. The concentrate from UOO 70 through line 90 is discharged to the tank BK 72 and through line 200 it is supplied to a mechanical filter M 13, where it is used as a flushing medium during periodic loosening regeneration of the filter layer 131 as it becomes contaminated. In this case, the contaminated flushing medium through line 400 is discharged into the sewer, and the excess amount of clean washing medium remaining in the filter after regeneration of the filter layer 131 is returned via line 300 back to BC 72. The last operation, as noted above, is performed in order to exclude the influx UOE 70 concentrate with a salt content of 4-5 times higher than in the source water and, accordingly, prevent deterioration of permeate quality.

Consider the conditions for the accumulation of a sufficient volume of UO concentrate, necessary for loosening regeneration of a mechanical filter:

- the minimum flow rate of the concentrate UOO is 20% of the incoming flow rate, which corresponds to the maximum hydraulic efficiency 80%

- the minimum duration of the filter cycle of a mechanical filter is 10 hours;

- the maximum time of loosening regeneration of the filter layer of a mechanical filter is 20 minutes.

Table 1 shows the relevant indicators for the three sizes of mechanical filters.

As can be seen from table 1, despite the choice of boundary (worst) conditions, the volume of UO concentrate accumulated over 10 hours exceeds the volume of the flushing medium required for loosening regeneration of the filter layer of a mechanical filter.

Consequently, the condition of the sufficiency of the concentrate will be all the more fulfilled if the boundary values deviate in a favorable direction, in which the volume of accumulated UO concentrate will exceed the volume of the washing medium necessary for the regeneration of the filter layer of the mechanical filter, i.e.

- increasing the consumption of concentrate UOO more than 20% of the flow of water entering the UOO;

- increasing the duration of the filter cycle of the mechanical filter over 10 hours;

- reducing the time of loosening regeneration of less than 20 minutes.

Table 2 shows the ratio of the required volume of the concentrate and the volume of the filter layer of the mechanical filter, which determines the required volume of the concentrate tank depending on the volume of material of the filter layer.

* Note: data taken from table 1.

Execution example

The source water with a flow rate of 83 m ³ / h enters the clarifier VTI-100, where it is treated with aluminum sulfate. The coagulated water after the clarifier with a flow rate of 81 m ³ / h enters the clarified water tank, from where it is supplied to a mechanical filter with a diameter of 3.4 m with a filter layer height of 1.0 m and a loading volume of 10 m ³ . The clarified and purified water after a mechanical filter with a flow rate of 81 m ³ / h is supplied to a reverse osmosis desalination plant with a capacity of 65 m ³ / h. UO concentrate with a flow rate of 16 m ³ / h enters the concentrate tank with a capacity of 180 m ³ . For 10 hours of operation of the PSU, the volume of concentrate accumulated in the tank will be 160 m ³ .

After 10 hours of operation, the mechanical filter switches to loosening regeneration. The concentrate from the tank with a flow rate of 455 m ³ / h is passed from bottom to top through a mechanical filter at a speed of 50 m / h for 20 minutes. The total flow rate of the concentrate fed for loosening regeneration is 152 m ³ . After the end of the loosening regeneration, the volume of concentrate remaining in the mechanical filter in the amount of 18 m ³ is discharged into the concentrate tank.

Excessive volume of concentrate (in excess of the mechanical filter required for loosening regeneration of the filter layer) can be discharged into the sewer. More rationally, the entire available volume of concentrate should be fed for loosening regeneration.

In the given embodiment, the ratio of the required volume of the concentrate tank to the volume of the filter layer in the mechanical filter is 18.

If there are at least two parallel-connected mechanical filters with a filter layer in the UPR 10, they are loosened regeneration as they become contaminated.

Industrial applicability

The make-up water preparation system according to the invention meets the condition of “industrial applicability”. The essence of the technical solution is disclosed in the formula, description and drawing clearly enough for understanding and industrial implementation by appropriate specialists based on the current level of technology in the field of water treatment.

Claims (7)

1. The system for the preparation of make-up water for heat-generating installations of thermal power plants or industrial boiler houses, containing sequentially included: initial water pre-treatment unit, which includes mechanical filters with a filter layer, and a reverse osmosis desalination unit with a concentrate collection tank and a concentrate discharge line attached to the bottom of said tank, characterized in that: the concentrate discharge line from the corresponding tank of the reverse osmosis desalination plant is connected to the lower part of each of these mechanical filters to use the specified concentrate as a washing medium during loosening regeneration of the filter layer as it becomes contaminated in each of these filters, and to the bottom of each mechanical filter there is additionally connected a discharge line to the concentrate tank of an excess volume of clean washing medium after completion of the process of loosening regeneration of the filter layer. 2. The make-up water preparation system according to claim 1, characterized in that the ratio of the volume of said concentrate collection tank to the volume of the filter layer of one mechanical filter is 15-20.

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