CN102491605A - Construction method for carrying out high dehydration on dredging slurry by using swirling flow, condensation, and plate-and-frame - Google Patents

Abstract

The invention relates to a construction method for highly dehydrating dredging mud by using swirling flow - concentration - plate frame, which is to send 15-20% dredging mud to the coarse vibrating screen through the conveying device to screen out large particles and impurities; Then the mud is separated in a large cyclone separator to obtain downgoing mud and upgoing mud; the downgoing mud is passed through a fine vibrating screen to obtain slag on the sieve and thick slurry after sieving, and the upgoing mud flows into the coagulation sedimentation tank to obtain concentrated mud and The supernatant; after the screened thick slurry and concentrated mud are settled in the mud storage tank, they are dehydrated by a plate and frame filter press to obtain mud cakes and press filter tail water; the dregs and mud cakes on the screen are used as engineering fills, The clear liquid and filter press tail water are treated by the tail water treatment system and then discharged up to standard. Grading and quickly reduce the moisture content of low-concentration dredging mud, effectively solving the problem of large quantities of dredging mud occupying land and not being able to be used directly.

Description

A construction method for highly dewatering dredging mud by using cyclone-concentration-plate frame

technical field

The invention relates to a high dehydration construction method of dredging mud, which uses the combination of swirling flow, concentration and plate frame, and belongs to the field of resources and environment.

Background technique

In recent years, in order to improve the navigation and water supply capacity of inland rivers and improve the water quality of rivers and lakes, many rivers and eutrophic lakes (such as Taihu Lake, Chaohu Lake, Dianchi Lake, etc.) in my country are carrying out large-scale dredging projects. At present, the conventional treatment method of domestic dredging silt is mainly to store it in the yard, and after storage, it is treated in situ as land use, or it is used as filling material after various improvements.

Most of the dredging projects in China use the cutter suction sludge dredging and filling equipment. Due to the limitation of this type of equipment and its conveying process, the concentration of dredging and filling sludge is low, between 15-20%, which results in sediment When cleared, it becomes mud, the volume increases to 4-5 times of the original, and the output reaches about 3000m ³ /h. Therefore, the scale of the subsequent silt storage yard is very large, and the area occupied is very considerable. At present, most of the dredging projects in my country have different degrees of storage yard problems, which seriously restrict the progress of dredging projects.

In order to solve the problem of dredging sludge occupying the storage yard, technical improvements can be made from the intermediate treatment of dredging slurry, and a more efficient and rapid dehydration method can be used to reduce the moisture content of the slurry to a level that can be directly used as fill.

state. Since most of the urban construction in our country requires a large amount of filling materials, the dredged silt can find the final outlet by converting it into filling materials.

The invention patent with the publication number CN101956412A involves the use of the centrifugal force generated by the hydrocyclone to separate and concentrate the mud, but the patent involves the sand mining technology of the dredger. , is very different from the separation used for sludge in this patent.

Contents of the invention

The purpose of the invention is to solve the problem that a large amount of low-concentration dredging mud occupies the stockyard and the tail water of the stockyard pollutes the environment. Through the implementation of the invention, the treatment time of dredging mud can be shortened, the treatment efficiency can be improved, and the treated slag and mud cake can be directly used as filling soil, thereby avoiding land occupation of the dredging stockyard and pollution to the environment.

The purpose of the present invention is achieved through the following technical solutions.

A construction method for highly dewatering dredging mud by using cyclone-concentration-plate frame, comprising the following steps:

(1) Use dredging equipment to dredge river and lake sediment;

(2) Send the sludge into the coarse vibrating screen through the conveying device to screen out the large particles and impurities in the sludge;

(3) Put the coarsely screened mud into the cyclone separator with a pressure pump, and separate the downgoing mud and upgoing mud; specifically, the cyclone separator separates the mud particles with a particle size greater than 30 μm, and the mud particles are separated by the lower part of the cyclone. The mud particles with particle size less than 30μm are discharged from the grit chamber, and are discharged from the overflow port on the upper part of the cyclone;

(4) After the downgoing mud passes through the fine vibrating screen, slag on the screen with low moisture content and thick slurry after sieving are obtained, and the upgoing mud flows into the coagulation sedimentation tank to obtain concentrated mud and supernatant; the screen mesh of the vibrating screen 20μm;

(5) Thick slurry after sieving and concentrated slurry in coagulation sedimentation tank are deposited in the mud storage tank, and then dehydrated with high concentration by plate and frame filter press to obtain mud cake and press filter tail water;

(6) The slag on the screen and the dewatered mud cake of the plate and frame filter press can be directly used as engineering fill. The supernatant of the sedimentation tank and the tail water of the filter press are treated by the tail water treatment system and discharged safely after reaching the standard.

The advantages of the present invention are:

(1) The 15-20% concentration mud output from dredging is directly screened and dehydrated without being temporarily stored in the stockyard, which avoids the problem of land occupation in the stockyard;

(2) The combined use of three dehydration methods improves the dehydration efficiency of dredging mud, reduces the time of mud dehydration, and can accelerate the progress of sludge treatment projects;

(3) The dredging slurry first passes through the cyclone separator, which can quickly separate the large particle size above 30 μm, which reduces the pressure of subsequent dehydration treatment and can improve the efficiency of plate and frame filter press dehydration;

(4) The moisture content of the dregs and mud cakes obtained after being treated by the cyclone separator and the plate-and-frame filter press is between 30% and 35%, which can be directly transported as filling.

(5) After the supernatant of the sedimentation tank and the tail water of the filter press are treated by the tail water treatment system, they can be safely discharged up to the standard, which reduces the pollution of the tail water to the surrounding environment.

Description of drawings

Fig. 1 is a process flow diagram of the present invention.

In Fig. 1: 1, dredging ship; 2, 5-20mm vibrating screen; 3, cyclone separator; 4, descending mud; 5, ascending mud; 6, fine vibrating screen of 20 μm; 8. Slag; 9. Coagulation sedimentation tank; 10. Concentrated mud; 11. Supernatant; 12. Mud storage tank; 13. Plate and frame filter press; 14; Mud cake; 15. Press filter tail water; 16 1. Tail water treatment system; 17. Sedimentation tank; 18. Rapid filter tank; 19. Constructed wetland.

Detailed ways

Example

The present invention will be further described below in conjunction with specific embodiment according to above-mentioned accompanying drawing again:

Fig. 1 is a process flow diagram of the present invention, with reference to shown in Fig. 1, a kind of construction method that utilizes swirl-concentration-plate frame to carry out dredging mud height dehydration comprises the following steps:

(1) Use the dredging equipment on the dredging vessel 1 to dredge the sediment of a lake in Jiangsu. The concentration of the dredging slurry is between 15-20%.

(2) Send the dredging mud to the 5-20mm coarse vibrating screen 2 through the conveying device on the dredging ship, and the coarse vibrating screen removes large particles and impurities in the mud;

(3) Pump the coarsely screened mud into the large-scale cyclone separator 3 with a pressure pump, and separate the downward mud with a particle size greater than 30 μm from the cyclone separator 4 and discharge it through the grit chamber, and the upward mud with a particle size of less than 30 μm 5 Discharged through the overflow port;

(4) After the descending mud passes through the 20 μm fine vibrating screen 6, the over-sieve muck 8 and the thick slurry 7 after the sieve are obtained with a lower moisture content. The upward mud flows into the coagulation sedimentation tank 9 to obtain concentrated mud 10 and supernatant 11;

(5) Thick slurry 7 and concentrated mud 10 after screening pass through mud storage tank 12 and finally reach plate and frame filter press 13 for high-concentration dehydration to obtain mud cake 14 and filter press tail water 15 with a moisture content of 30-35%;

(6) The dregs 8 and mud cake 14 on the sieve can be directly used as engineering fill, and the supernatant 11 of the sedimentation tank and the tail water 15 of the filter press are treated by the tail water treatment system 16 and discharged safely after reaching the standard.

Claims (3)

1. one kind is utilized eddy flow-concentrated-sheet frame to carry out the constructional method of desilting mud height dehydration, may further comprise the steps:

(1) utilize desilting equipment that river lakebed mud is carried out desilting;

(2) through transport unit mud is sent into thick vibratory screening apparatus, large particulate matter and the impurity in the mud is removed in scalping;

The mud that (3) will pass through scalping is squeezed in the cyclone separator with pressure pump, separates to obtain descending mud and up mud;

(4) descending mud obtains dregs and sieve back underflow on the lower sieve of water ratio behind meticulous vibratory screening apparatus, and up mud flows into coagulative precipitation tank, obtains concentrating mud and supernatant;

(5) the concentrated mud of sieve back underflow and coagulative precipitation tank carries out the high density dehydration through the storage basin post precipitation through plate-and-frame filter press, obtains mud cake and press filtration tail water;

(6) mud cake after the dehydration of dregs and plate-and-frame filter press can directly banket as engineering on the sieve, and settling tank supernatant and press filtration tail water is safety dumping up to standard after the tail water treatment system is handled.

2. a kind of eddy flow-concentrated-sheet frame that utilizes described in the claim 1 carries out the constructional method of desilting mud height dehydration; It is characterized in that cyclone separator is isolated particle diameter greater than 30 μ m mud particles in the step (3); Spigot by the swirler-bottom is discharged; Particle diameter is discharged by the riser on swirler-top less than 30 μ m mud particles.

3. a kind of eddy flow-concentrated-sheet frame that utilizes described in the claim 1 carries out the constructional method of desilting mud height dehydration, and the screen cloth mesh that it is characterized in that the vibratory screening apparatus in above-mentioned (4) step is 20 μ m.