CN110894116A

CN110894116A - Zero-emission treatment system for circulating cooling water

Info

Publication number: CN110894116A
Application number: CN201911198039.8A
Authority: CN
Inventors: 俞建德; 曹霞; 刘磊
Original assignee: ZHEJIANG DEAN TECHNOLOGY Co Ltd
Current assignee: ZHEJIANG DEAN TECHNOLOGY Co Ltd
Priority date: 2019-11-29
Filing date: 2019-11-29
Publication date: 2020-03-20

Abstract

The invention discloses a circulating cooling water zero discharge treatment system which comprises an electrocoagulation module, a filtering module, a sedimentation module and a dewatering module, wherein the electrocoagulation module comprises an electrocoagulation pool and a slag collecting tank, a slag discharge port is formed in the side surface of the slag collecting tank, a first water inlet, a first water outlet and a first sludge discharge port are formed in the electrocoagulation pool, the filtering module comprises a DE type filter pool and a backwashing sewage discharge tank, a second water inlet and a second water outlet are formed in the DE type filter pool, a third water outlet is formed in the backwashing sewage discharge tank, a third water inlet, a fourth water outlet and a second sludge discharge port are formed in the sedimentation module, the dewatering module comprises a dewaterer with an inlet connected with the flocculation tank, the flocculation tank is communicated with a medicine outlet of a medicine soaking machine, the first sludge discharge port and the second sludge discharge port are respectively communicated with an inlet of the flocculation tank, and a fifth water outlet and a third sludge discharge port are formed. The system has only one water inlet and one water outlet, has good treatment effect and can really realize high-efficiency zero-emission treatment on the circulating cooling water.

Description

Zero-emission treatment system for circulating cooling water

Technical Field

The invention relates to a sewage treatment system, in particular to a circulating cooling water zero-discharge treatment system.

Background

China is a water-deficient country, the annual water supply amount of each person is below 1000 tons, which is lower than the international standard, and faces a severe water shortage situation. The circulating cooling water is a large item of water used in industrial water, and in the industries of petrochemical industry, electric power, steel, metallurgy and the like, the consumption of the circulating cooling water accounts for 50-90% of the total water used by enterprises. Cooling water is continuously recycled in a circulating system, and due to the rising of water temperature, the change of flow speed, evaporation, the concentration of various inorganic ions and organic substances, a cooling tower and a cooling water tank are subjected to the comprehensive effects of sunlight irradiation, wind and rain, the entering of dust and sundries, the structure and materials of equipment and the like outdoors, so that a plurality of problems can be caused. In the existing circulating cooling water treatment, after circulating cooling water is concentrated to a certain multiple, certain concentrated water must be removed, and new water must be supplemented. If the sewage treatment equipment of the existing domestic power plant mostly adopts a reverse osmosis treatment process, although a certain treatment effect can be achieved, about 25% of inlet water is still directly discharged in a concentrated water form after reverse osmosis, the resource waste is large, and the directly discharged concentrated water can cause adverse effects on surface water and the environment.

Disclosure of Invention

The invention aims to solve the technical problem of providing a circulating cooling water zero-emission treatment system aiming at the defects of the prior art.

The technical scheme adopted by the invention for solving the technical problems is as follows: a circulating cooling water zero-discharge treatment system comprises an electric flocculation module, a filtering module, a precipitation module and a dewatering module, wherein the electric flocculation module comprises an electric flocculation tank and a slag collecting tank arranged at the top of the electric flocculation tank, a slag discharge port is formed in the side face of the slag collecting tank, a first water inlet, a first water outlet and a first sludge discharge port are formed in the electric flocculation tank, the first water inlet is communicated with an external circulating cooling water discharge system, the filtering module comprises a transverse DE type filtering tank and a backwashing sewage discharge tank which are communicated, a second water inlet and a second water outlet are formed in the DE type filtering tank, the second water inlet is communicated with the first water outlet, the second water outlet is communicated with an external circulating cooling water supply system, a third water outlet is formed in the sewage discharge backwashing tank, and a third water inlet, a third water outlet, a third water inlet, a third water outlet and a third sludge discharge outlet are formed in the precipitation module, Fourth delivery port and second row mud mouth, the third delivery port with the third inlet communicate with each other, the fourth delivery port with first water inlet communicate with each other, the dehydration module include the hydroextractor, the entrance of hydroextractor connect and be equipped with the flocculation groove, the flocculation groove communicate with each other with the medicine outlet of a bubble medicine machine, first row mud mouth with the second row mud mouth respectively with the entry of flocculation groove communicate with each other, the hydroextractor on seted up fifth delivery port and third row mud mouth, the fifth delivery port with first water inlet communicate with each other, the third row mud mouth be used for the mud cake that obtains after the outer row of dehydration.

According to the circulating cooling water zero-discharge treatment system, external circulating cooling water is introduced into the electric flocculation module through the first water inlet, and after the circulating cooling water from the external circulating cooling water discharge system is subjected to step-by-step comprehensive treatment through the electric flocculation module, the filtering module, the precipitation module and the dehydration module, the circulating cooling water is discharged into the external circulating cooling water supply system through the second water outlet in the filtering module. The treatment system of the invention has only one outward water inlet and one outward water outlet, has good treatment effect and can really realize high-efficiency zero-emission treatment on the circulating cooling water.

Preferably, the electrocoagulation tank comprises a first tank body, an electrode plate group, a water distribution plate and a slag scraping device, wherein a first water inlet is transversely formed in the side wall of the first tank body, the electrode plate group is arranged in the first tank body and consists of a plurality of electrode plates which are arranged at intervals from front to back, the water distribution plate is vertically arranged in the first tank body and is positioned between the first water inlet and the electrode plate group, a plurality of first water distribution holes are formed in the water distribution plate at intervals, the slag scraping device is arranged at the top of the slag collecting tank, the slag collecting tank is adjacent to the first water collecting tank, a water outlet weir is vertically arranged between the slag collecting tank and the first water collecting tank, the upper edge of the water outlet weir is provided with a row of saw teeth, and a first water outlet is arranged at the bottom of the first water collecting tank, the bottom of the first tank body is a sludge collecting groove with a large upper part and a small lower part, and the first sludge discharge port is arranged at the bottom of the sludge collecting groove. Above-mentioned electrocoagulation pool has changed the mode that traditional electrocoagulation pool bottom was intake, changes into the side of following first cell body and transversely intakes, and the cooperation water distribution board can realize the even intake of electrocoagulation pool, and simultaneously, the even play water of electrocoagulation pool can be guaranteed to the play weir, improves the electrocoagulation effect.

Further, the slag scraping device comprises a motor, a first track and a second track, the first track is horizontally arranged, the second track is obliquely arranged, the first track is wound on a first roller and a second roller, the first roller and the second roller are respectively installed on the first tank body, a third roller is installed at the output end of the motor, and the second track is wound on the second roller and the third roller. During the use, this scrape sediment device will scrape the dross of getting and arrange outward, simultaneously, the supernatant at first cell body top can overflow to the water catch bowl in and arrange to the filtering module in.

Preferably, a filter frame and a suction washing device are arranged in the DE type filter tank, filter cloth is arranged on the filter frame, the suction washing device comprises a sucker, the sucker is connected with a sucker driving device and arranged on the outer side of the filter frame, the sucker comprises a first cavity and a second cavity, a central hole is formed in the side wall of the first cavity, a drain pipe is installed at the central hole, a suction plate is covered on one side of the second cavity and provided with a suction seam communicated with the second cavity, the first cavity and the second cavity are separated by a partition plate, the second cavity comprises a plurality of sub cavities which are sequentially connected in rows, the partition plate is provided with a plurality of suction holes which are in one-to-one correspondence with the sub cavities, and the sub cavities are communicated with the first cavity through the suction holes, the plurality of suction holes are symmetrically arranged on two sides of the central hole, and the aperture of each suction hole is gradually increased along with the gradual increase of the distance from the central hole. The sucker can ensure that the suction and the washing in the DE type filter chamber are more uniform. The suction force of the suction holes closer to the central hole is larger, and the hole diameter of the suction holes is designed to be increased along with the gradual increase of the distance from the central hole, so that the uniform suction and washing effect of the suction disc can be ensured, the backwashing efficiency is improved, and sewage generated by backwashing can smoothly flow into the backwashing sewage discharge tank.

Preferably, the sedimentation module comprises a vertical flow sedimentation tank, the vertical flow sedimentation tank comprises a second tank body, the second tank body is provided with a fourth water inlet and a sixth water outlet, the bottom of the second tank body is provided with a conical hopper with a large upper part and a small lower part, a mud scraping device is arranged in the second tank body and comprises a scraper driving device, a central transmission shaft and a scraper, the central transmission shaft is connected with the output end of the scraper driving device, the scraper is fixed on the central transmission shaft, the scraper is positioned on the inner side of the hopper, and a second mud discharge port is arranged at the bottom of the hopper. In the sewage treatment process, scraper blade drive arrangement can drive central transmission shaft and scraper blade and slowly rotate, and the scraper blade can play the sludge scraping and stirring effect in the mud fill as the sludge concentration district, increases the mobility of mud, makes mud can last smooth discharge from the mud discharging port, avoids the mud jam condition, and is effectual to the sediment of mud, guarantees the continuity and the mud discharging efficiency of mud discharging, ensures water purification effect.

Furthermore, the scraper plate comprises a plurality of inclined plates, the inclined plates are fixedly connected with the central transmission shaft through a plurality of connecting rods respectively, each inclined plate is parallel to the inner side surface of the mud bucket, and a gap is formed between each inclined plate and the inner side surface of the mud bucket. The arrangement of the plurality of inclined plates ensures the mud scraping effect, has a certain flow guide effect and can promote the mud to flow to the second mud discharge port.

Preferably, a vertically arranged central cylinder, a sleeve and a sludge turnover box are fixed in the second tank body, the sleeve is sleeved outside the central cylinder, the sleeve and the central cylinder enclose a closed annular cavity, the fourth water inlet and the sixth water outlet are respectively positioned at the upper part of the second tank body, a water inlet pipe transversely penetrates through the fourth water inlet, the water inlet pipe is communicated with the annular cavity, the lower part of the central cylinder is provided with an opening, the side wall of the central cylinder is provided with a plurality of through holes, the inner cavity of the central cylinder is communicated with the annular cavity through the plurality of through holes, the central cylinder is sleeved outside the central transmission shaft, the sludge turnover box is erected above the sludge hopper, the outer side surface of the sludge turnover box and the inner side surface of the second tank body enclose an annular channel, the upper part of the mud dumping box is provided with an opening, the lower part of the central transmission shaft penetrates through the mud dumping box and extends into the mud bucket, and the lower parts of the sleeve and the central cylinder respectively extend into the bottom of the mud dumping box. By utilizing the gravity principle, mud, floccules, colloids and the like in the sewage from the backwashing sewage discharge tank are slowly deposited at the middle lower part of the sludge turning tank, supernatant overflows from the upper part of the sludge turning tank and is accumulated in the tank body, and water finally flows out of the tank body from the sixth water outlet along with the continuous rising of the water level in the tank body. Along with the accumulation of mud, floccule, colloid etc. in turning over the mud case, formed one deck "natural filter layer" in turning over the mud incasement, play the filtering action to the follow-up sewage that constantly gets into in the mud case that turns over, filter the interception with mud and pollutant, played certain quality of water purification effect, improved the efficiency that sewage vertical flow deposits. And finally, as the sludge is deposited more and more in the sludge turnover box, the sludge overflows from the upper part of the sludge turnover box and continuously flows into the mud bucket through the annular channel under the action of the self weight of the sludge. The central cylinder, the sleeve and the sludge turning box are matched for use, so that the flow of sewage is more concentrated, the sewage can be intensively introduced into the sludge turning box, and supernatant is discharged firstly after natural sedimentation in the sludge turning box. At the initial stage of sewage treatment, the sludge-water mixture is mainly used in the sludge turning box, and along with the increase of the sludge amount deposited in the sludge turning box, supernatant firstly overflows from the upper part of the sludge turning box, and when the sludge in the sludge turning box is accumulated to a certain amount, the supernatant also overflows from the upper part of the sludge turning box.

Furthermore, a plurality of first supporting cross rods are fixed on the outer side of the mud turning box, the mud turning box is fixed at the bottom of the second tank body through the plurality of first supporting cross rods, a plurality of second supporting cross rods are fixed on the inner side of the mud turning box, and two ends of each second supporting cross rod are respectively fixed on the sleeve and the mud turning box. The first supporting cross rod and the second supporting cross rod can improve the strength of the mud turning box and facilitate the installation of the mud turning box.

Preferably, the lower part of the central cylinder is communicated with a water distribution device, the water distribution device is suspended in the sludge turning box, and when the sludge turning box is used, sewage in the central cylinder flows through the water distribution device and enters the sludge turning box; the water distribution device comprises an even number of water distribution pipes which are horizontally arranged by taking the central transmission shaft as a center, the lower part of each water distribution pipe is provided with a plurality of second water distribution holes, the plurality of second water distribution holes are arranged at intervals along the length direction of each water distribution pipe, and the plurality of second water distribution holes are symmetrically arranged by taking a longitudinal section passing through the center line of each water distribution pipe as a center; the aperture of the second water distribution hole on each water distribution pipe is gradually increased along with the gradually increased distance from the central transmission shaft. The water distribution device can improve the uniformity of water distribution. Besides the function of uniform water distribution, the water distribution device also plays a certain surging role on the sludge in the sludge turning box, so that the redundant sludge overflows from the upper part of the sludge turning box and falls into the annular channel and the sludge hopper to be concentrated, and the continuity of sludge discharge is improved. In the water treatment process, sewage flows in from the middle of the sludge turning box, and the design of the second water distribution holes with gradually increased pore diameters is adopted, so that the uniform water distribution is further ensured.

Preferably, a cylindrical overflow weir is arranged in the second tank body, a circle of saw teeth are arranged on the upper edge of the overflow weir, the overflow weir is arranged on the upper part of the inner side of the second tank body, the outer diameter of the overflow weir is smaller than the inner diameter of the second tank body, an annular water collecting tank with an upper opening is defined by the outer side surface of the overflow weir and the inner side surface of the second tank body, and the sixth water outlet is communicated with the water collecting tank. The overflow weir has a buffering effect, can prevent a large amount of water from flowing to the sixth water outlet, and ensures the water treatment effect. A circle of saw teeth on the upper edge of the overflow weir can play a further role in buffering.

Compared with the prior art, the invention has the following advantages: according to the circulating cooling water zero-discharge treatment system, external circulating cooling water is introduced into the electric flocculation module through the first water inlet, and after the circulating cooling water from the external circulating cooling water discharge system is subjected to step-by-step comprehensive treatment through the electric flocculation module, the filtering module, the precipitation module and the dehydration module, the circulating cooling water is discharged into the external circulating cooling water supply system through the second water outlet in the filtering module. The treatment system of the invention has only one outward water inlet and one outward water outlet, has good treatment effect and can really realize high-efficiency zero-emission treatment on the circulating cooling water.

Drawings

FIG. 1 is a block diagram of a circulating cooling water zero-discharge treatment system in an embodiment in a top view;

FIG. 2 is a front view of an electroflocculation module in an embodiment;

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2;

FIG. 4 is a cross-sectional view taken along line B-B of FIG. 2;

FIG. 5 is an external view of an effluent weir in an electroflocculation module;

FIG. 6 is a front view of the suction cup in the DE filter (with the suction plate removed);

FIG. 7 is a cross-sectional view taken at C-C of FIG. 6;

FIG. 8 is a cross-sectional view taken along line D-D of FIG. 6;

FIG. 9 is a longitudinal sectional view corresponding to FIG. 6;

FIG. 10 is a left side view corresponding to FIG. 6;

FIG. 11 is an external view of a suction plate of the suction cup;

FIG. 12 is a schematic structural diagram of a vertical flow sedimentation tank in the embodiment;

FIG. 13 is a schematic diagram showing the size arrangement of water distribution holes on water distribution pipes in a vertical flow sedimentation tank;

FIG. 14 is a schematic view (top view) of a water distribution device comprising 2 water distribution pipes connected to a central cylinder and a central transmission shaft;

FIG. 15 is a schematic view (top view) of a water distribution device comprising 4 water distribution pipes connected to a central cylinder and a central transmission shaft;

FIG. 16 is a schematic view (top view) of a water distribution device comprising 8 water distribution pipes connected to a central cylinder and a central transmission shaft;

FIG. 17 is a schematic cross-sectional view of a water distribution pipe having 1 arrangement of water holes;

FIG. 18 is a schematic cross-sectional view of a water distribution pipe having 3 water distribution holes;

FIG. 19 is a schematic cross-sectional view of a water distributor with 4 rows of water holes.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

The system for zero discharge treatment of recirculated cooling water in example 1, as shown in fig. 1, includes an electrocoagulation module, a filtration module, a precipitation module and a dehydration module, the electrocoagulation module includes an electrocoagulation cell 11 and a slag collection tank 12 disposed at the top of the electrocoagulation cell 11, a slag discharge port 13 is disposed on the side surface of the slag collection tank 12, the electrocoagulation cell 11 is provided with a first water inlet 14, a first water outlet 15 and a first sludge discharge port 16, the first water inlet 14 is communicated with an external recirculated cooling water discharge system, the filtration module includes a DE-type filter 21 and a backwash sewage discharge tank 22 which are transversely communicated, the DE-type filter 21 is provided with a second water inlet 23 and a second water outlet 24, the second water inlet 23 is communicated with the first water outlet 15, the second water outlet 24 is communicated with an external recirculated cooling water supply system, the backwash sewage discharge tank 22 is provided with a third water outlet 25, the precipitation module is provided with a third water inlet 31, The fourth water outlet 32 is communicated with the third water inlet 31, the fourth water outlet 32 is communicated with the first water inlet 14, the dewatering module comprises a dewatering machine 41, a flocculation tank 42 is connected to an inlet of the dewatering machine 41, the flocculation tank 42 is communicated with a medicine outlet of the medicine soaking machine 40, the first sludge outlet 16 and the second sludge outlet 33 are respectively communicated with an inlet of the flocculation tank 42, the dewatering machine 41 is provided with a fifth water outlet 43 and a third sludge outlet 44, the fifth water outlet 43 is communicated with the first water inlet 14, and the third sludge outlet 44 is used for discharging sludge cakes obtained after dewatering. The flow paths are shown by arrows in figure 1.

In example 1, as shown in fig. 2 to 4, an electrocoagulation cell 11 includes a first cell body 111, an electrode plate group, a water distribution plate 113, and a slag scraping device, a first water inlet 14 is transversely formed in a side wall of the first cell body 111, the electrode plate group is disposed in the first cell body 111, the electrode plate group is composed of a plurality of electrode plates 112 disposed at intervals in front and behind, the water distribution plate 113 is vertically disposed in the first cell body 111, the water distribution plate 113 is disposed between the first water inlet 14 and the electrode plate group, a plurality of first water distribution holes 114 are spaced on the water distribution plate 113, the slag scraping device is disposed at the top of a slag collecting tank 12, the slag collecting tank 12 is adjacent to a first water collecting tank 17, a water outlet weir 18 is vertically disposed between the slag collecting tank 12 and the first water collecting tank 17, as shown in fig. 5, an upper edge of the water outlet weir 18 is provided with a row of saw teeth, a first water outlet 15 is disposed at the bottom of the first water collecting tank 17, a sludge collecting tank, the first sludge discharge port 16 is provided at the bottom of the sludge collection tank 115.

In embodiment 1, the slag scraping device includes a motor 116, a first horizontal track 117 and a second inclined track 118, the first track 117 is wound around a first roller 119 and a second roller 120, the first roller 119 and the second roller 120 are respectively installed on the first tank 111, a third roller 121 is installed at an output end of the motor 116, and the second track 118 is wound around the second roller 120 and the third roller 121.

In embodiment 1, a filter frame (not shown in the figure) and a suction washing device are arranged in the DE type filter 21, filter cloth is arranged on the filter frame, the suction washing device includes a suction cup 26, the suction cup 26 is connected with a suction cup driving device (not shown in the figure), the suction cup 26 is arranged on the outer side of the filter frame, as shown in fig. 6 to 11, the suction cup 26 includes a first cavity 261 and a second cavity 262, a central hole 263 is arranged on the side wall of the first cavity 261, a drain pipe 27 is arranged at the central hole 263, a suction plate 264 is arranged on one side of the second cavity 262, a suction slit 265 communicated with the second cavity 262 is arranged on the suction plate 264, the first cavity 261 and the second cavity 262 are separated by a partition plate 28, the second cavity 262 includes six sub-cavities 266 which are sequentially connected in a row, six suction holes 29 corresponding to the six sub-cavities 266 are arranged on the partition plate 28, the six sub-cavities 266 are communicated with the first cavity 261 through the central holes 29, the six suction holes 29 are symmetrically arranged, the aperture diameter of the suction hole 29 gradually increases as the distance from the central hole 263 gradually increases.

The circulating cooling water zero-emission treatment system of embodiment 2 differs from embodiment 1 in that in embodiment 2, the sedimentation module includes a vertical flow sedimentation tank 30, as shown in fig. 12, the vertical flow sedimentation tank 30 includes a second tank body 34, a fourth water inlet 35 and a sixth water outlet 36 are provided on the second tank body 34, a tapered mud bucket 37 with a large top and a small bottom is provided at the bottom of the second tank body 34, a mud scraping device is provided in the second tank body 34, the mud scraping device includes a scraper driving device 38, a central transmission shaft 39 and a scraper, in this embodiment, the scraper driving device 38 employs a motor, the central transmission shaft 39 is connected with an output end of the scraper driving device 38, the scraper is fixed on the central transmission shaft 39, the scraper is located inside the mud bucket 37, and the second mud discharge port 33 is provided at the bottom of the mud bucket 37; the scraper comprises a plurality of inclined plates 301, the inclined plates 301 are fixedly connected with the central transmission shaft 39 through a plurality of connecting rods 302 respectively, each inclined plate 301 is arranged in parallel with the inner side surface of the mud bucket 37, and a gap 303 is formed between each inclined plate 301 and the inner side surface of the mud bucket 37. The flow routing is shown by the arrows in fig. 12.

In the embodiment 2, a vertically arranged central cylinder 51 is fixed in the second tank body 34, the sleeve 52 is sleeved outside the central cylinder 51, the sleeve 52 and the central cylinder 51 enclose a closed annular cavity 54, the fourth water inlet 35 and the sixth water outlet 36 are respectively positioned at the upper part of the second tank body 34, the fourth water inlet 35 is transversely provided with a water inlet pipe 541, the water inlet pipe 541 is communicated with the annular cavity 54, the lower part of the central cylinder 51 is opened, the side wall of the central cylinder 51 is provided with a plurality of through holes 55, the inner cavity of the central cylinder 51 is communicated with the annular cavity 54 through the plurality of through holes 55, the central cylinder 51 is sleeved outside the central transmission shaft 39, the mud turning box 53 is erected above the mud bucket 37, the outer side surface of the mud turning box 53 and the inner side surface of the second tank body 34 enclose an annular channel 56, the upper part of the mud turning box 53 is opened, the lower part of the central transmission shaft 39 penetrates through the mud turning box 53 and extends into the mud bucket 37, and the lower parts of the sleeve 52 and the central cylinder 51 respectively extend into the bottom; the lower part of the central cylinder 51 is communicated with a water distribution device which is suspended in the sludge turning tank 53, when in use, sewage in the central cylinder 51 flows through the water distribution device and enters the sludge turning tank 53; the water distribution device comprises even number of water distribution pipes 57 which are horizontally arranged by taking the central transmission shaft 39 as the center, the lower part of each water distribution pipe 57 is provided with a plurality of second water distribution holes 58, the plurality of second water distribution holes 58 are arranged at intervals along the length direction of each water distribution pipe 57, and the plurality of second water distribution holes 58 are symmetrically arranged by taking a longitudinal section passing through the central line of each water distribution pipe 57 as the center; as shown in fig. 13, the diameter of the second water distribution holes 58 of each water distribution pipe 57 is gradually increased as the distance from the central drive shaft 39 is gradually increased.

In example 2, the number of the water distribution pipes 57 is even, and may be 2 (as shown in fig. 14), 4 (as shown in fig. 15), 8 (as shown in fig. 16), or other even numbers. The number of the water distribution holes 58 symmetrically arranged centering on the longitudinal section passing through the center line of each water distribution pipe 57 may be 1 row (as shown in fig. 17), 3 rows (as shown in fig. 18), 4 rows (as shown in fig. 19) or other rows.

In embodiment 2, a plurality of first support cross bars 59 are fixed on the outer side of the sludge turnover tank 53, the sludge turnover tank 53 is fixed at the bottom of the second tank body 34 through the plurality of first support cross bars 59, a plurality of second support cross bars 50 are fixed on the inner side of the sludge turnover tank 53, and two ends of each second support cross bar 50 are respectively fixed on the sleeve 52 and the sludge turnover tank 53.

In embodiment 2, a cylindrical overflow weir 6 is disposed in the second tank 34, a ring of saw teeth is disposed on an upper edge of the overflow weir 6, the overflow weir 6 is disposed on an upper portion of an inner side of the second tank 34, an outer diameter of the overflow weir 6 is smaller than an inner diameter of the second tank 34, an annular water collecting tank 61 with an upper opening is defined by an outer side surface of the overflow weir 6 and an inner side surface of the second tank 34, and the sixth water outlet 36 is communicated with the water collecting tank 61.

In the above embodiments, the DE type filter 21, the suction washing device, the dewatering machine 41, and the medicine soaking machine 40 all adopt the prior art, for example: the DE type filter 21 may be a filter tank disclosed in ZL200910097605.6, the suction washing device may be a suction washing device for filter tanks disclosed in ZL200910100890.2, the dewatering device 41 may be a screw extrusion type sludge dewatering device disclosed in ZL201010108726.9, and the soaking machine 40 may be a solid water treatment agent dosing tank disclosed in ZL 200820083562.7.

The working principle of the circulating cooling water zero-discharge treatment system is as follows: circulating cooling water discharged by an external circulating cooling water discharge system enters an electric flocculation tank 11, after electric flocculation treatment, floating slag floats to a slag collection tank 12 and is discharged through a slag discharge port 13, bottom sediments in the electric flocculation tank 11 are discharged into a flocculation tank 42 and enter a dehydrator 41, and supernate enters a DE type filter 21; supernatant from the electrocoagulation cell 11 is continuously filtered and backwashed in the DE type filter 21, the clear water obtained by treatment is discharged into an external circulating cooling water supply system to be recycled, while sewage generated by backwashing horizontally flows into the backwashing sewage discharge tank 22, is treated in the backwashing sewage discharge tank 22 and then enters a precipitation module, and the water treated in the backwashing sewage discharge tank 22 is still sewage containing certain sludge; the sewage from the backwashing sewage discharge tank 22 is further treated in the precipitation module, the supernatant generated in the precipitation module flows back to the electric flocculation tank 11 for continuous treatment, the bottom precipitate in the precipitation module enters the dehydrator 41 through the flocculation tank 42 and is dehydrated in the dehydrator 41, the obtained deslimed water is discharged into the electric flocculation tank 11 for continuous treatment, and the sludge cake obtained by dehydration is discharged and collected.

The whole treatment system of the invention only has one outward water inlet (namely the first water inlet 14) and one outward water outlet (namely the second water outlet 24), has good treatment effect, and can really realize high-efficiency zero-emission treatment on the circulating cooling water.

Claims

1. The circulating cooling water zero-discharge treatment system is characterized by comprising an electric flocculation module, a filtering module, a precipitation module and a dewatering module, wherein the electric flocculation module comprises an electric flocculation tank and a slag collecting tank arranged at the top of the electric flocculation tank, a slag discharge port is formed in the side surface of the slag collecting tank, a first water inlet, a first water outlet and a first sludge discharge port are formed in the electric flocculation tank, the first water inlet is communicated with an external circulating cooling water discharge system, the filtering module comprises a DE type filtering tank and a backwashing sewage discharge tank which are transversely communicated, a second water inlet and a second water outlet are formed in the DE type filtering tank, the second water inlet is communicated with the first water outlet, the second water outlet is communicated with an external circulating cooling water supply system, a third water outlet is formed in the backwashing sewage discharge tank, and a third water inlet and a third water outlet are formed in the precipitation module, Fourth delivery port and second row mud mouth, the third delivery port with the third inlet communicate with each other, the fourth delivery port with first water inlet communicate with each other, the dehydration module include the hydroextractor, the entrance of hydroextractor connect and be equipped with the flocculation groove, the flocculation groove communicate with each other with the medicine outlet of a bubble medicine machine, first row mud mouth with the second row mud mouth respectively with the entry of flocculation groove communicate with each other, the hydroextractor on seted up fifth delivery port and third row mud mouth, the fifth delivery port with first water inlet communicate with each other, the third row mud mouth be used for the mud cake that obtains after the outer row of dehydration.

2. The system of claim 1, wherein the electrocoagulation cell comprises a first cell body, an electrode plate group, a water distribution plate and a slag scraping device, the first water inlet is transversely arranged on a side wall of the first cell body, the electrode plate group is arranged in the first cell body, the electrode plate group comprises a plurality of electrode plates which are arranged at intervals in the front and at the back, the water distribution plate is vertically arranged in the first cell body, the water distribution plate is arranged between the first water inlet and the electrode plate group, a plurality of first water distribution holes are arranged on the water distribution plate at intervals, the slag scraping device is arranged at the top of the slag collecting tank, the slag collecting tank is adjacent to the first water collecting tank, a water outlet weir is vertically arranged between the slag collecting tank and the first water collecting tank, and the upper edge of the water outlet weir is provided with saw teeth, the first water outlet is arranged at the bottom of the first water collecting tank, the bottom of the first tank body is a sludge collecting tank with a large upper part and a small lower part, and the first sludge discharge port is arranged at the bottom of the sludge collecting tank.

3. The circulating cooling water zero-emission treatment system as claimed in claim 2, wherein the slag scraping device comprises a motor, a first horizontal track and a second inclined track, the first track is wound on a first roller and a second roller, the first roller and the second roller are respectively installed on the first tank body, a third roller is installed at the output end of the motor, and the second track is wound on the second roller and the third roller.

4. The circulating cooling water zero emission treatment system according to claim 1, wherein a filter frame and a suction washing device are arranged in the DE type filter tank, filter cloth is arranged on the filter frame, the suction washing device comprises a sucker, the sucker is connected with a sucker driving device and is arranged on the outer side of the filter frame, the sucker comprises a first cavity and a second cavity, a central hole is formed in the side wall of the first cavity, a drain pipe is installed at the central hole, a suction plate covers one side of the second cavity, a suction seam communicated with the second cavity is formed in the suction plate, the first cavity and the second cavity are separated by a partition plate, the second cavity comprises a plurality of sub-cavities which are sequentially connected in a row, and the partition plate is provided with a plurality of suction holes which are in one-to-one correspondence with the sub-cavities, the plurality of sub-cavities are communicated with the first cavity through the plurality of suction holes, the plurality of suction holes are symmetrically distributed on two sides of the central hole, and the aperture of the suction holes is gradually increased along with the gradual increase of the distance from the central hole.

5. The recirculating cooling water zero-emission treatment system as recited in claim 1, wherein the sedimentation module comprises a vertical flow sedimentation tank, the vertical flow sedimentation tank comprises a second tank body, the second tank body is provided with a fourth water inlet and a sixth water outlet, a conical hopper with a large upper end and a small lower end is arranged at the bottom of the second tank body, a sludge scraping device is arranged in the second tank body, the sludge scraping device comprises a scraper driving device, a central transmission shaft and a scraper, the central transmission shaft is connected with an output end of the scraper driving device, the scraper is fixed on the central transmission shaft, the scraper is located on the inner side of the hopper, and the second sludge discharge port is arranged at the bottom of the hopper.

6. The zero-emission treatment system of circulating cooling water as claimed in claim 5, wherein the scraper comprises a plurality of inclined plates, the inclined plates are fixedly connected with the central transmission shaft through a plurality of connecting rods, each inclined plate is arranged in parallel with the inner side surface of the mud bucket, and a gap is formed between each inclined plate and the inner side surface of the mud bucket.

7. The circulating cooling water zero emission treatment system according to claim 5, wherein a vertically arranged center barrel, a sleeve and a sludge turnover box are fixed in the second tank body, the sleeve is sleeved outside the center barrel, the sleeve and the center barrel define a closed annular cavity, the fourth water inlet and the sixth water outlet are respectively positioned at the upper part of the second tank body, a water inlet pipe transversely penetrates through the fourth water inlet, the water inlet pipe is communicated with the annular cavity, the lower part of the center barrel is opened, the side wall of the center barrel is provided with a plurality of through holes, the inner cavity of the center barrel is communicated with the annular cavity through the plurality of through holes, the center barrel is sleeved outside the center transmission shaft, the sludge turnover box is erected above the sludge hopper, the outer side surface of the sludge turning box and the inner side surface of the second tank body form an annular channel, the upper part of the sludge turning box is open, the lower part of the central transmission shaft penetrates through the sludge turning box and extends into the sludge hopper, and the lower parts of the sleeve and the central cylinder respectively extend into the bottom of the sludge turning box.

8. The recirculated cooling water zero emission treatment system according to claim 6, wherein a plurality of first support cross bars are fixed to an outer side of the sludge turnover tank, the sludge turnover tank is fixed to a bottom of the second tank body through the plurality of first support cross bars, a plurality of second support cross bars are fixed to an inner side of the sludge turnover tank, and both ends of each of the second support cross bars are respectively fixed to the sleeve and the sludge turnover tank.

9. The system of claim 6, wherein the lower part of the central cylinder is communicated with a water distribution device which is suspended in the sludge turnover tank, and when the system is used, sewage in the central cylinder flows through the water distribution device and enters the sludge turnover tank; the water distribution device comprises an even number of water distribution pipes which are horizontally arranged by taking the central transmission shaft as a center, the lower part of each water distribution pipe is provided with a plurality of second water distribution holes, the plurality of second water distribution holes are arranged at intervals along the length direction of each water distribution pipe, and the plurality of second water distribution holes are symmetrically arranged by taking a longitudinal section passing through the center line of each water distribution pipe as a center; the aperture of the second water distribution hole on each water distribution pipe is gradually increased along with the gradually increased distance from the central transmission shaft.

10. The zero-emission treatment system of circulating cooling water as claimed in claim 5, wherein a cylindrical weir is disposed in the second tank, a ring of saw teeth is disposed on an upper edge of the weir, the weir is disposed on an upper portion of an inner side of the second tank, an outer diameter of the weir is smaller than an inner diameter of the second tank, an annular water collection tank with an upper opening is defined by an outer side surface of the weir and an inner side surface of the second tank, and the sixth water outlet is communicated with the water collection tank.