CN108101268B

CN108101268B - Self-sustaining recycling process for treating ballast stone washing wastewater

Info

Publication number: CN108101268B
Application number: CN201810113184.0A
Authority: CN
Inventors: 李科; 杨永见; 曹平
Original assignee: Sichuan Boqu Technology Co ltd
Current assignee: Sichuan Boqu Technology Co ltd
Priority date: 2018-02-05
Filing date: 2018-02-05
Publication date: 2020-07-14
Anticipated expiration: 2038-02-05
Also published as: CN108101268A

Abstract

The invention relates to the technical field of water pollution treatment. Aims to provide a self-sustaining recycling process for treating ballast stone washing wastewater. The technical scheme adopted by the invention is as follows: the method sequentially comprises the following steps: A. cleaning the railway ballast; B. collecting waste water; C. removing primary coarse sand; D. removing secondary fine sand; E. precipitating in an inclined tube; F. pre-flocculation and post-coagulation treatment; G. naturally settling; H. sludge concentration treatment; I. sludge dewatering treatment; J. the water self-sustaining circulates. The invention can greatly improve the treatment effect of the ballast stone washing wastewater, remove coarse sand, fine sand and SS in the stone washing wastewater, greatly reduce the consumption of water resources and realize the self-sustaining circulation of the stone washing wastewater.

Description

Self-sustaining recycling process for treating ballast stone washing wastewater

Technical Field

The invention relates to the technical field of water pollution treatment, in particular to a self-sustaining recycling process for treating ballast stone washing wastewater.

Background

With the needs of economic development and daily traffic, the strength of railway construction is increased sharply. The railway ballast is used as a foundation for bearing a track and a sleeper, and the water permeability and the stability of the railway ballast directly influence the safety of a railway. Therefore, in the process of manufacturing the railway ballast, the railway ballast needs to be washed, and a large amount of impurities carried in the railway ballast are removed. However, the ballast stone washing wastewater contains a large amount of suspended substances SS, and if the suspended substances SS are not treated, the suspended substances are directly discharged, so that the environment is greatly influenced. In the prior art, a complete set of equipment for treating ballast stone washing wastewater is lacked, and the conventional water treatment equipment has many defects, such as: 1. the water consumption is large, and huge water resource waste is caused. 2. The sand content of the stone washing wastewater is high, and the traditional equipment has poor treatment effect on the wastewater and the like.

Disclosure of Invention

The invention aims to provide a self-sustaining recycling process for treating ballast stone washing wastewater, so as to solve the problems.

In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows: a self-sustaining recycling process for treating ballast stone washing wastewater sequentially comprises the following steps:

A. cleaning the railway ballast: washing the railway ballast by using a washing vibrating screen;

B. collecting waste water: collecting waste water generated after cleaning by using a U-shaped aqueduct;

C. removing primary coarse sand: introducing the collected wastewater into a spiral sand-water separator for primary coarse sand removal;

D. removing secondary fine sand: introducing the wastewater from which the primary coarse sand is removed into a hydraulic cyclone sand remover for secondary fine sand removal;

E. inclined tube precipitation: introducing the wastewater from which the secondary fine sand is removed into an inclined tube sedimentation tank, and removing part of SS in advance after natural sedimentation to obtain sludge; the obtained sludge is directly introduced into a sludge discharge tank;

F. pre-flocculation and post-coagulation treatment: introducing the wastewater precipitated by the inclined tube into a flocculation precipitator, adding a flocculating agent into the wastewater to form a primary flocculating body, and then adding a coagulant aid into the wastewater to form a flocculating body with larger particles by means of net catching and bridge support, so that the sedimentation is easier; a PH value regulator is added in a matched manner in the reaction process of the flocculating agent and the coagulant aid to regulate the PH value;

G. natural sedimentation treatment: after the pre-flocculation and post-coagulation treatment, the mixture of the flocculating constituent and water naturally settles in a flocculation precipitator, the water body reaching the standard on the upper layer of the flocculation precipitator is directly discharged into a reuse water pool, the flocculating constituent settles and forms sludge on the lower layer of the flocculation precipitator, and the obtained sludge is introduced into a sludge discharge pool;

H. sludge concentration treatment: introducing sludge in the sludge discharge tank into a sludge concentration tank for concentration;

I. sludge dewatering treatment: after sludge concentration treatment, introducing the sludge into a sludge dewatering machine for dewatering;

J. self-sustaining circulation of water: and (4) connecting the water in the reuse water pool back to the washing vibrating screen again to clean the ballast.

Preferably, in the step H, the turbid liquid at the upper layer in the sludge concentration tank is introduced into the drainage tank; in the step I, introducing the turbid liquid obtained by dehydration into a drainage pool; and E, introducing the turbid liquid in the drainage pool into the inclined tube sedimentation pool in the step E again.

Preferably, in the step F, an ABC agent combination is adopted, the agent A is flocculant polyaluminium chloride, the agent B is coagulant aid polyacrylamide, and the agent C is a pH value regulator; the ratio of the medicament A to the medicament B to the medicament C is 80:12:1 in parts by mass.

Preferably, the reuse water tank is communicated with a municipal water supply network, and water is supplemented through the municipal water supply network.

Preferably, the flocculation precipitator comprises a plurality of flocculation cylinders which are arranged side by side and are communicated with each other, the upper part of each flocculation cylinder is cylindrical, the lower part of each flocculation cylinder is inverted conical, and a liquid inlet pipe is arranged on the side wall of the flocculation precipitator and is connected with a water outlet of the inclined tube sedimentation tank through the liquid inlet pipe; the bottom of each flocculation cylinder is provided with a sludge discharge pipe and is communicated with a sludge discharge pool through the sludge discharge pipe, a vertical stirring shaft is also arranged in each flocculation cylinder, the top end of the stirring shaft is connected with a stirring motor fixedly arranged at the top of the flocculation cylinder, and the peripheral surface of the stirring shaft is provided with a plurality of groups of stirring blades; a plurality of drain pipes are vertically arranged on the side wall of the flocculation precipitator, which is far away from one side of the liquid inlet pipe, and drain valves are arranged on the drain pipes; and the flocculation precipitator is also provided with a dosing device for adding a flocculating agent and a coagulant aid into the flocculation precipitator.

Preferably, the stirring shaft is a hollow shaft, a plurality of groups of short medicine discharging pipes are arranged on the stirring shaft, and the plurality of groups of short medicine discharging pipes and the stirring blades are distributed at intervals; the medicine outlet short pipe extends along the radial direction of the stirring shaft and is communicated with the inside of the stirring shaft; the dosing device comprises a dosing sleeve sleeved outside the stirring shaft, the upper end and the lower end of the dosing sleeve are respectively connected with the stirring shaft through bearing sets, each bearing set comprises an upper bearing and a lower bearing, and sealing filler is arranged between the upper bearing and the lower bearing; a gap communicated with the inner surface and the outer surface of the stirring shaft is arranged on the side wall of the stirring shaft opposite to the middle section of the dosing sleeve; the utility model discloses a flocculating and precipitating device, including flocculating agent storage cylinder and coagulant aid storage cylinder, add medicine sleeve one side still be provided with the medicine that advances of the inside intercommunication of medicine sleeve and be responsible for, advance medicine and be responsible for and stretch out outside the flocculating settling ware and store up cartridge case intercommunication with the flocculating agent respectively through flocculating agent branch pipe and coagulant aid branch pipe, be provided with the medicine valve on flocculating agent branch pipe and the coagulant aid branch pipe respectively.

Preferably, a dosing pump is arranged on the medicine inlet main pipe.

Preferably, a stirring device for stirring sludge is arranged in the sludge concentration tank, the stirring device comprises a rotating shaft vertically arranged at the center in the sludge concentration tank, a frame-shaped stirring frame is arranged at the lower part of the rotating shaft, a plurality of strip-shaped stirring plates are fixedly arranged at the bottom of the stirring frame, and the stirring plates extend along the radial direction of the rotating shaft; the bottom of the sludge concentration tank is provided with an inverted conical groove, the bottom of the rotating shaft is fixedly provided with a positioning block matched with the groove, and the positioning block is positioned in the groove; the middle part of the stirring frame is connected with the upper part of the rotating shaft through an inclined pull steel cable.

Preferably, the top of the sludge concentration tank is provided with a mounting bracket, and the mounting bracket is provided with a transparent glass cover.

Preferably, the sludge dewatering machine is one of a plate-and-frame type sludge dewatering machine, a belt type sludge dewatering machine, a centrifugal type sludge dewatering machine and a stacked screw type sludge dewatering machine.

The beneficial effects of the invention are concentrated and expressed as follows: the treatment effect of stone waste water is washed to improvement railway ballast that can be very big gets rid of coarse sand, fine sand and SS in washing the stone waste water, very big reduction the consumption of water resource, realized washing the self-sustaining circulation of stone waste water.

1. Because the stone waste water is washed to the railway ballast has high sand content, adopts U type aqueduct to collect waste water, can effectual reduction grit impurity's deposition volume, guarantees to wash the normal collection of stone waste water, prevents to block up.

2. Performing primary treatment on the wastewater by using a spiral sand-water separator, and removing coarse sand with the thickness of 2-10mm contained in the wastewater, wherein the separation rate reaches 99%; then the waste water is treated by a hydraulic cyclone desander for the second stage, fine sand with the diameter of 0.2-2mm contained in the waste water is removed, and the separation rate reaches more than 90 percent.

3. And the wastewater is naturally precipitated by using the inclined tube sedimentation tank, and part of SS suspended matters can be removed in advance without adding a medicament, so that the aims of saving the medicament and reducing the operating cost are fulfilled.

4. Then in the step of pre-flocculation and post-coagulation treatment, a flocculating agent is added in the earlier stage of the process to form a primary flocculating constituent, and then a coagulant aid is added into the wastewater to form a larger granular flocculating constituent. Can effectively improve the precipitation efficiency and thoroughly remove SS suspended matters in the wastewater.

5. And supplementing the standard water after the preposed flocculation and postposition coagulation aiding treatment into a reuse water tank, and then using the water in the reuse water tank for cleaning the ballast. The circulating work can be realized only by adding medicine and supplementing water, so that the water resource is saved, and the operation cost is further reduced.

Drawings

FIG. 1 is a schematic view of the structure of the apparatus for use of the present invention;

FIG. 2 is a schematic diagram of the structure of a flocculation precipitator;

FIG. 3 is a schematic view of the installation of the medicated cannula;

fig. 4 is a schematic structural view of a sludge thickener.

Detailed Description

The self-sustaining recycling process for treating the ballast stone washing wastewater, which is shown in the combined drawings of 1-4, sequentially comprises the following steps:

A. cleaning the railway ballast: and cleaning the railway ballast by using the water washing vibrating screen 1.

B. Collecting waste water: the U-shaped aqueduct 2 is used for collecting waste water generated after cleaning, and the U-shaped aqueduct 2, namely the water drainage open channel with the U-shaped section, is usually arranged in an overhead manner and has a certain gradient as the water drainage open channel usually needs to pass through the upper part of a railway line. Adopt U type aqueduct 2 to collect waste water, can effectual reduction grit impurity's deposition volume, guarantee to wash the normal collection of stone waste water, prevent to block up.

C. Removing primary coarse sand: and introducing the wastewater collected by the U-shaped aqueduct 2 into a spiral sand-water separator 3 for primary coarse sand removal. The wastewater is subjected to primary treatment by using the spiral sand-water separator 3, coarse sand with the particle size of 2-10mm contained in the wastewater is removed, and the separation rate reaches 99%. The sand material outlet end of the spiral sand-water separator 3 is also generally provided with a shaftless spiral sand conveyer for conveying sand materials to a stock ground for uniform stacking.

D. Removing secondary fine sand: and (4) introducing the wastewater from which the primary coarse sand is removed into a hydraulic cyclone sand remover 4 for secondary fine sand removal. The cyclone desander 4 carries out secondary treatment on the wastewater, removes 0.2-2mm of fine sand contained in the wastewater, the separation rate reaches more than 90%, and after the sand-water separation twice, coarse sand and fine sand in the wastewater are well separated, so that the universality is high, and the method can be suitable for the treatment of various ballast stone washing wastewater.

E. Inclined tube precipitation: and (3) introducing the wastewater from which the secondary fine sand is removed into an inclined tube sedimentation tank 5, and removing part of SS in advance after natural sedimentation to obtain sludge. The obtained sludge is directly introduced into the sludge discharge tank 6, and the sludge is treated uniformly when the storage amount reaches a certain degree. According to the invention, the wastewater is subjected to natural sedimentation treatment through the inclined tube sedimentation tank 5, and part of SS suspended matters can be removed in advance without adding a medicament, so that the aims of saving the medicament and reducing the operation cost are fulfilled.

F. Pre-flocculation and post-coagulation treatment: the wastewater precipitated by the inclined tube is introduced into a flocculation precipitator 7, a flocculating agent is added into the wastewater to form a primary flocculating constituent, and then a coagulant aid is added into the wastewater to form a flocculating constituent with larger particles by netting and bridge frame, so that the sedimentation is easier. And (3) adding a pH value regulator in a matching manner in the reaction process of the flocculating agent and the coagulant aid to regulate the pH value. The essence of the process steps of the pre-flocculation and post-coagulation treatment is that a flocculating agent is added into the wastewater in the early stage to form a primary flocculating constituent, and then a coagulant aid is added into the wastewater to form a larger granular flocculating constituent. Because the granule of flocculating constituent is bigger, can effectual improvement precipitation efficiency to thoroughly get rid of the SS suspended solid in the waste water.

The method comprises the steps of performing pre-flocculation and post-coagulation treatment, wherein an ABC medicament combination is adopted, a flocculating agent is adopted, polyaluminium chloride is preferably adopted, a coagulant B is adopted, polyacrylamide is preferably adopted, a pH value regulator is adopted, and a commercially available conventional medicament is adopted as the pH value regulator, wherein the medicament A, the medicament B and the medicament C are mixed according to the mass ratio of 80:12:1, the dosage of the medicament C is slightly adjusted according to actual conditions, the normally up-and-down floating part is 0.1-0.2, and the ABC medicament combination according to the mixture ratio has better universality through detection, and can reach SS concentration of less than or equal to 50 mg/L aiming at various ballast stone washing wastewater, which is greatly lower than the SS concentration of national first-level water discharge standard.

The preposed flocculation post-coagulation assisting treatment is carried out in a flocculation precipitator 7, the flocculation precipitator 7 can be a conventional flocculation precipitator 7 which is commonly sold in the market, and of course, in order to improve the treatment effect on SS and improve the utilization rate of the medicament, the better method can be carried out. The flocculation precipitator 7 comprises a plurality of flocculation barrels 13 which are arranged side by side and are communicated with each other, the upper part of the flocculation barrels 13 is cylindrical, the lower part of the flocculation barrels is in an inverted cone shape, the upper part of the flocculation barrels 13 is used as a main area of flocculation reaction, and the lower part of the flocculation barrels is used as a main area of flocculating constituent precipitation. The flocculation cylinders 13 of the flocculation settler 7 can be of an integral structure, and can be assembled in sections for convenient equipment transportation, as long as the sealing performance among the flocculation cylinders 13 is ensured, which is not described herein again.

The side wall of the flocculation precipitator 7 is provided with a liquid inlet pipe 14 and is connected with the water outlet of the inclined tube sedimentation tank 5 through the liquid inlet pipe 14. The bottom of each flocculation cylinder 13 is provided with a sludge discharge pipe 15 and is communicated with the sludge discharge tank 6 through the sludge discharge pipe 15, and flocculating constituents produced after wastewater reacts with a flocculating agent and a coagulant aid in the flocculation precipitator 7 are precipitated and enter the sludge discharge tank 6 through the sludge discharge pipe 15. The flocculation precipitator 7 is generally arranged above the sludge discharge tank 6 in an overhead manner, sludge is discharged into the sludge discharge tank 6 by utilizing natural gravity, a sludge pump can be arranged on the sludge discharge pipe 15 in a matching manner, and when the sludge is not discharged smoothly, the sludge pump is used for sucking in a matching manner.

The flocculation effect of SS in the wastewater in the flocculation precipitator 7 is affected by the performance of the flocculant and coagulant aid medicament, and is also related to the utilization rate of the medicament. Therefore, the flocculation precipitator 7 should be stirred to improve the utilization rate of the medicament. A vertical stirring shaft 16 is also arranged in each flocculation cylinder 13, the top end of the stirring shaft 16 is connected with a stirring motor fixedly arranged at the top of the flocculation cylinder, and a plurality of groups of stirring blades 17 are arranged on the peripheral surface of the stirring shaft 16. The stirring shaft 16 is driven by the stirring motor, and the stirring shaft 16 drives the stirring paddle 17, so that the full reaction of the medicament and the wastewater is realized.

Certainly, in order to add the chemicals into the flocculation precipitator 7, the flocculation precipitator 7 of the present invention is further provided with a chemical adding device for adding the flocculant and the coagulant aid into the flocculation precipitator 7, and the chemical adding device may be a chemical adding port and a plurality of chemical storage tanks arranged at the top of the flocculation precipitator 7. The medicaments in the medicament storage tanks can be added into the flocculation precipitator 7 through the medicament adding openings. But in order to increase the dispersion of the agent in the flocculation settler 7 and to increase its utilization. More preferably, as shown in fig. 2 and 3, the stirring shaft 16 is a hollow shaft, the stirring shaft 16 is provided with a plurality of groups of short drug discharging pipes 20, and the plurality of groups of short drug discharging pipes 20 are spaced from the stirring blades 17. The medicine outlet short pipe 20 extends along the radial direction of the stirring shaft 16 and is communicated with the inside of the stirring shaft 16. After the medicine adding device leads the medicine into the stirring shaft 16, the medicine in the medicine adding device is thrown out through the medicine outlet short pipe 20 by utilizing the rotation of the stirring shaft 16, so that the medicine is uniformly distributed in the flocculation precipitator 7.

The dosing device comprises a dosing sleeve 21 sleeved outside the stirring shaft 16, the upper end and the lower end of the dosing sleeve 21 are connected with the stirring shaft 16 through bearing sets 22 respectively, each bearing set 22 comprises an upper bearing and a lower bearing, and sealing filler is arranged between the upper bearing and the lower bearing, so that the sealing of the filler between the dosing sleeve 21 and the stirring shaft 16 is realized. And a notch 23 communicated with the inner surface and the outer surface of the stirring shaft 15 is formed in the side wall of the stirring shaft 16 opposite to the middle section of the dosing sleeve 21, and the medicament enters the stirring shaft 15 through the notch 23. It still is provided with and advances medicine main pipe 24 with the inside intercommunication of medicine sleeve 21 to add medicine sleeve 21 one side, it stretches out outside the flocculation precipitator 3 and stores up cartridge case and coagulant aid storage case intercommunication with the flocculating agent respectively through flocculating agent branch pipe 25 and coagulant aid branch pipe 26 to advance medicine main pipe 24, be provided with respectively on flocculating agent branch pipe 25 and the coagulant aid branch pipe 26 and add medicine valve 27, add medicine valve 27 and adopt solenoid valve usually, realize the interpolation of different medicaments through the control corresponding medicine valve 27.

In the process of high-speed rotation of the stirring shaft 16, negative pressure is formed in the stirring shaft 16 after the medicament in the stirring shaft 16 is thrown out, the medicament is automatically supplemented into the stirring shaft 16 from the medicament storage cylinder, namely the stirring shaft 16 also has a certain pumping function when rotating at high speed. However, considering that the stirring shaft 16 has a poor or substantially lost pumping effect when rotating at a low speed, it is preferable that the main medicine inlet pipe 24 is provided with a medicine feeding pump. Utilize the medicine feeding pump pressure boost, go into (mixing) shaft 16 with the medicament pump in to guarantee that (mixing) shaft 16 is under high-speed and low-speed, charge device homoenergetic provides stable medicine.

G. Natural sedimentation treatment: after the preposed flocculation and postposition coagulation-aiding treatment, the mixture of the flocculating constituent and water naturally settles in the flocculation precipitator 7, the water body reaching the standard on the upper layer of the flocculation precipitator 7 is directly discharged into the reuse water tank 8, the flocculating constituent settles and forms sludge on the lower layer of the flocculation precipitator 7, and the obtained sludge is introduced into the sludge discharge tank 6. The side wall of the flocculation precipitator 7 far away from the liquid inlet pipe 14 is vertically provided with a plurality of drainage pipes 18, and the drainage pipes 18 are provided with drainage valves 19. As shown in fig. 2, the intake pipe 14 is located at the left side, and the discharge pipe 18 is located at the right side. The number of the drainage pipes 18 may be two or more, and here, taking two as an example, the two drainage pipes 18 are sequentially arranged from top to bottom, and each drainage pipe 18 is provided with one drainage valve 19. After the precipitation is completed, the drain valve 19 is opened, and the water reaching the standard at the upper layer can be drained into the reuse water tank 8 through the drain pipe 18. Due to the fact that the plurality of discharge pipes 18 are arranged, a worker can selectively open the drain valves 19 on the drain pipes 18 with the corresponding heights according to actual conditions, and the automatic water discharge device can adapt to various different working conditions.

H. Sludge concentration treatment: and (3) introducing the sludge in the sludge discharge tank 6 into a sludge concentration tank 9 for concentration. A stirring device used for stirring the sludge is arranged in the sludge concentration tank 9, and the stirring device can adopt a structure that a rotating shaft is matched with a stirring paddle and a stirring rod. By stirring the sludge, evaporation of water is promoted to remove excess water from the sludge. However, when the sludge is stirred, if the sludge with a higher water content is directly concentrated, the time is longer, and for this reason, it is better to introduce the upper turbid liquid in the sludge concentration tank 9 into the drainage tank 11 in the step H. And then the turbid liquid in the drainage pool 11 is introduced into the inclined tube sedimentation pool 5 in the step E again, so that the time length of the concentration process can be reduced, and the removal rate of SS in the wastewater is further improved.

Since the concentration of the sludge is increased and the viscosity of the sludge is increased during the concentration process, it is better to use the stirring device as shown in fig. 4, the stirring device includes a rotating shaft 28 vertically arranged at the center in the sludge concentration tank 9, a frame-shaped stirring frame 29 is arranged at the lower part of the rotating shaft 28, a plurality of strip-shaped stirring plates 30 are fixedly arranged at the bottom of the stirring frame 29, and the stirring plates 30 extend along the radial direction of the rotating shaft 28. The bottom of the sludge concentration tank 9 is provided with a groove 31 in an inverted cone shape, the bottom of the rotating shaft 28 is fixedly provided with a positioning block 32 matched with the groove 31, and the positioning block 32 is positioned in the groove 31. The middle part of the stirring frame 29 is connected with the upper part of the rotating shaft 28 through a diagonal cable 33. In the rotating process of the rotating shaft 28, the positioning block 32 at the lower end of the rotating shaft is positioned in the groove 31, so that the stability of the rotating shaft in the rotating process is improved, the sludge also has a certain lubricating effect on the friction between the positioning block 32 and the groove 31, and the rotating shaft is simple in structure, good in effect and extremely long in service life. In addition, the inclined pull steel cable 33 can also play a role in strengthening, so that the stirring frame 29 is prevented from deforming in the process of long-term use.

Besides, the top of the sludge concentration tank 9 can be provided with a mounting bracket 34, and the mounting bracket 34 is provided with a transparent glass cover 35. Thereby make full use of solar energy to heat mud, further improved concentrated efficiency. The glass cover 35 not only serves as a separation part and plays a role of a cover, so that the heat loss in the sludge concentration tank 9 is reduced, meanwhile, the solar short wave radiation can penetrate through the glass cover 35, the reflected radiation is long wave radiation, and the penetration of the glass cover 35 is poor, so that the glass cover 35 can be arranged to enable the invention to fully utilize solar energy in the concentration process.

I. Sludge dewatering treatment: after the sludge is concentrated, the sludge is introduced into a sludge dewatering machine 10 for dewatering. The sludge dewatering machine 6 can adopt one of a plate-and-frame type sludge dewatering machine, a belt type sludge dewatering machine, a centrifugal type sludge dewatering machine and a stacked screw type sludge dewatering machine, or a plurality of the sludge dewatering machines are connected in series in sequence for use. Because the turbid liquid generated after the sludge dehydration contains more impurities and is not convenient to directly discharge, the better method is that in the step I, the turbid liquid obtained after the dehydration is introduced into the drainage pool 11, and then the turbid liquid in the drainage pool 11 is introduced into the inclined tube sedimentation pool 5 in the step E again, so that the zero pollution discharge in the true sense is realized.

J. Self-sustaining circulation of water: connect the washing shale shaker 1 again with the water in the reuse pond 8, wash the railway ballast, that is to say utilize the water up to standard in the reuse pond 8 to wash the railway ballast, realized the reuse to the water resource. According to the invention, the circular work can be realized only by adding chemicals and supplementing water, so that water resources are saved, and the operation cost is further reduced. In order to facilitate the water replenishing of the invention, the reuse water tank 8 is preferably connected with a municipal water supply network 12, and the water is replenished through the municipal water supply network 12.

Claims

1. A self-sustaining recycling process for treating ballast stone washing wastewater is characterized by comprising the following steps: the method sequentially comprises the following steps:

A. cleaning the railway ballast: washing the railway ballast by using a washing vibrating screen (1);

B. collecting waste water: collecting waste water generated after cleaning by using a U-shaped aqueduct (2);

C. removing primary coarse sand: introducing the collected wastewater into a spiral sand-water separator (3) for primary coarse sand removal;

D. removing secondary fine sand: introducing the wastewater after the primary coarse sand removal into a hydraulic cyclone sand remover (4) for secondary fine sand removal;

E. inclined tube precipitation: introducing the wastewater from which the secondary fine sand is removed into an inclined tube sedimentation tank (5), and removing part of SS in advance after natural sedimentation to obtain sludge; the obtained sludge is directly introduced into a sludge discharge tank (6);

F. pre-flocculation and post-coagulation treatment: introducing the wastewater precipitated by the inclined tube into a flocculation precipitator (7), adding a flocculating agent into the wastewater to form a primary flocculating body, and then adding a coagulant aid into the wastewater to form a flocculating body with larger particles by netting and bridge frame, so that the wastewater is easier to precipitate; adding a pH value regulator in a matching way in the reaction process of the flocculating agent and the coagulant aid to regulate the pH value;

G. natural sedimentation treatment: after the preposed flocculation and postposition coagulation aiding treatment, the mixture of the flocculating constituent and water naturally settles in a flocculation precipitator (7), the water body reaching the standard on the upper layer of the flocculation precipitator (7) is directly discharged into a reuse water tank (8), the flocculating constituent forms sludge on the lower layer of the flocculation precipitator (7) after settling, and the obtained sludge is introduced into a sludge discharge tank (6);

H. sludge concentration treatment: the sludge in the sludge discharge tank (6) is introduced into a sludge concentration tank (9) for concentration;

I. sludge dewatering treatment: after sludge concentration treatment, sludge is introduced into a sludge dewatering machine (10) for dewatering;

J. self-sustaining circulation of water: the water in the reuse water pool (8) is connected back to the washing vibrating screen (1) again to wash the ballast;

the flocculation precipitator (7) comprises a plurality of flocculation cylinders (13) which are arranged side by side and are communicated with each other, the upper parts of the flocculation cylinders (13) are cylindrical, the lower parts of the flocculation cylinders are inverted conical, and a liquid inlet pipe (14) is arranged on the side wall of the flocculation precipitator (7) and is connected with a water outlet of the inclined pipe sedimentation tank (5) through the liquid inlet pipe (14); a sludge discharge pipe (15) is arranged at the bottom of each flocculation cylinder (13) and is communicated with the sludge discharge pool (6) through the sludge discharge pipe (15), a vertical stirring shaft (16) is also arranged in each flocculation cylinder (13), the top end of the stirring shaft (16) is connected with a stirring motor fixedly arranged at the top of the flocculation cylinder (13), and a plurality of groups of stirring blades (17) are arranged on the peripheral surface of the stirring shaft (16); a plurality of drainage pipes (18) are vertically arranged on the side wall of the flocculation precipitator (7) far away from the liquid inlet pipe (14), and drainage valves (19) are arranged on the drainage pipes (18); the flocculation precipitator (7) is also provided with a dosing device for adding a flocculating agent and a coagulant aid into the flocculation precipitator (7); the stirring shaft (16) is a hollow shaft, a plurality of groups of medicine discharging short pipes (20) are arranged on the stirring shaft (16), and the plurality of groups of medicine discharging short pipes (20) and the stirring blades (17) are distributed at intervals.

2. The self-sustaining recycling process for ballast stone washing wastewater treatment according to claim 1, characterized in that: in the step H, introducing the turbid liquid at the upper layer in the sludge concentration tank (9) into a drainage tank (11); in the step I, introducing the turbid liquid obtained by dehydration into a drainage pool (11); and then the turbid liquid in the drainage tank (11) is introduced into the inclined tube sedimentation tank (5) in the step E again.

3. The self-sustaining recycling process for ballast stone washing wastewater treatment according to claim 2, characterized in that: in the step F, an ABC medicament combination is adopted, wherein the medicament A is flocculant polyaluminium chloride, the medicament B is coagulant aid polyacrylamide, and the medicament C is a pH value regulator; the ratio of the medicament A to the medicament B to the medicament C is 80:12:1 in parts by mass.

4. The self-sustaining recycling process for ballast stone washing wastewater treatment according to claim 3, characterized in that: the reuse water tank (8) is communicated with a municipal water supply network (12) and is used for supplementing water through the municipal water supply network (12).

5. The self-sustaining recycling process for ballast stone washing wastewater treatment according to claim 1, characterized in that: the medicine outlet short pipe (20) extends along the radial direction of the stirring shaft (16) and is communicated with the inside of the stirring shaft (16); the dosing device comprises a dosing sleeve (21) sleeved outside the stirring shaft (16), the upper end and the lower end of the dosing sleeve (21) are respectively connected with the stirring shaft (16) through bearing sets (22), each bearing set (22) comprises an upper bearing and a lower bearing, and sealing filler is arranged between the upper bearing and the lower bearing; a gap (23) communicated with the inner surface and the outer surface of the stirring shaft (16) is arranged on the side wall of the stirring shaft (16) opposite to the middle section of the dosing sleeve (21); it still is provided with the medicine that advances who adds medicine sleeve (21) inside intercommunication and is responsible for (24) to add medicine sleeve (21) one side, it stretches out outside flocculation and precipitation ware (7) and stores up cartridge case and coagulant aid storage cartridge case intercommunication with the flocculating agent respectively through flocculating agent branch pipe (25) and coagulant aid branch pipe (26) to advance medicine person in charge (24), be provided with respectively on flocculating agent branch pipe (25) and coagulant aid branch pipe (26) and add medicine valve (27).

6. The self-sustaining recycling process for treating ballast stone washing wastewater according to claim 5, characterized in that: the medicine feeding main pipe (24) is provided with a medicine feeding pump.

7. The self-sustaining recycling process for treating ballast stone washing wastewater according to claim 6, characterized in that: a stirring device used for stirring sludge is arranged in the sludge concentration tank (9), the stirring device comprises a rotating shaft (28) vertically arranged at the center in the sludge concentration tank (9), a frame-shaped stirring frame (29) is arranged at the lower part of the rotating shaft (28), a plurality of strip-shaped stirring plates (30) are fixedly arranged at the bottom of the stirring frame (29), and the stirring plates (30) extend along the radial direction of the rotating shaft (28); a groove (31) in an inverted cone shape is formed in the bottom of the sludge concentration tank (9), a positioning block (32) matched with the groove (31) is fixedly arranged at the bottom of the rotating shaft (28), and the positioning block (32) is located in the groove (31); the middle part of the stirring frame (29) is connected with the upper part of the rotating shaft (28) through a diagonal steel cable (33).

8. The self-sustaining recycling process for ballast stone washing wastewater treatment according to claim 7, characterized in that: the top of the sludge concentration tank (9) is provided with a mounting bracket (34), and the mounting bracket (34) is provided with a transparent glass cover (35).

9. The self-sustaining recycling process for ballast stone washing wastewater treatment according to claim 8, characterized in that: the sludge dewatering machine (10) is one of a plate-and-frame type sludge dewatering machine, a belt type sludge dewatering machine, a centrifugal type sludge dewatering machine and a stacked screw type sludge dewatering machine.