CN104986927A

CN104986927A - Drying process for sludge with lower water content

Info

Publication number: CN104986927A
Application number: CN201510382063.2A
Authority: CN
Inventors: 孙浩
Original assignee: Tianjin Hope Environmental Protection Technology Co Ltd
Current assignee: Tianjin Hope Environmental Protection Technology Co Ltd
Priority date: 2015-07-02
Filing date: 2015-07-02
Publication date: 2015-10-21

Abstract

A drying process for sludge with lower water content comprises the following steps: 1) pretreating watery sludge: feeding sludge in a microwave treatment device for wall breaking, disinfecting and sterilizing, and adding the sludge, which has the water content of 75 to 85 percent after being sterilized, in a sludge storing box for storage; 2) uniformly and slowly adding a cationic polyacrylamide flocculant in a dissolver with stirring and heating functions, stirring with a stirring device at the revolving speed of 60-200 r/min, and avoiding long-time excessive mechanical shearing; 3) adding the sludge in the sludge storing box and the cationic polyacrylamide product solution in a flocculation tank for flocculoreaction, wherein the sludge stays for 10-30 min in the flocculation tank, introducing the flocculated sewage in a filter press to be subjected to primary drying and dewatering, and discharging the produced sewage from a water outlet pipe in the filter press. Electroosmotic dewatering is adopted, and stink caused by high temperature and harmful gases, such as dioxin, caused by high-temperature incineration are avoided.

Description

A kind of drying process of low water-bearing section mud

Technical field

The present invention relates to environmental technology field, particularly relate to a kind of drying process of low water-bearing section mud.

Background technology

Along with improving constantly of expanding economy and standard of living, the mud in urban life and trade effluent increase in numbers swiftly, and the wet mud that China produces every year is up to 1,200 ten thousand tons, and annual growth rate is between 10-15%.Because sludge treatment cost accounts for about 50% of sewage work's processing cost, cost is very high, therefore many sewage works of China often only process the process avoiding mud to sewage, and a landfill and stacking mode are main, have caused serious problem of environmental pollution.Through the purifying treatment of sewage work, discharge after reaching state sewage emission standard, the generation of mud also will roll up, and the most of pollutent in sewage is all transferred in mud, the common characteristic of these mud is that organic content is high, and particle is thin, there is high-hydrophilic, but dewatering is poor, and containing a large amount of bacteriums, pathogenic agent, some factory sludge is even containing heavy metal.At present, sludge dewatering is link very important in sewage treatment process, this link need complete two works for the treatment of: be separated the precipitated sludge completed in the sewage of harmless treatment, through its water ratio of mud of initial gross separation up to 99 ﹪, dehydration decrement must be carried out to it, sludge volume after dehydration decrement greatly reduces, and is beneficial to mud and carries out the successive projects such as landfill, burning.In general, the water ratio after sludge dewatering decrement is at about 80 ﹪, and in mud cake state, volume-diminished is to 20 ~ 30 original ﹪.Dewatering technology of mud is roughly divided into following a few class: mechanical expression formula; Heat drying formula, osmosis formula.The equipment that mechanical expression formula dewatering process adopts is as plate and frame(type)filter press, belt filter press, folded spiral shell formula sludge dewatering equipment, centrifugal drier etc.; Heat drying formula dewatering process adopt equipment as ultra-sonic oscillation water extracter, rotating disc type sludge drying machine etc.; Osmosis formula dewatering process causes industry extensively to pay attention in recent years, and made theoretic exploration and demonstration to its dehydration mechanism, confirming as is a kind of sludge dewatering novel process of less energy-consumption.Treatment process mainly landfill, burning, the compost etc. of current mud, because the water ratio from the mud of sewage work after mechanism filter-pressing is generally about 70%, if the water ratio of mud will be reduced to less than 40%, need to consume a large amount of energy, thus the mummification cost of mud is improved greatly.Therefore, a kind of process disposing technique actively mud being carried out to science is needed.

Summary of the invention

The object of this invention is to provide a kind of drying process of low water-bearing section mud.

Of the present inventionly to comprise the following steps:

1. the pre-treatment of water-containing sludge: mud is dropped in microwave heating appts and carry out broken wall, virus killing and sterilizing.By the water ratio after sterilizing be 75% ~ 85% mud add sewage sludge storage case store;

2. cationic polyacrylamide flocculant agent added at leisure uniformly in the dissolver of band stirring and heating measures, the whipping appts using per minute to transfer 60 ~ 200 turns to stirs, and should avoid mechanical shearing excessively acute for a long time;

3. the mud in sewage sludge storage case and cationic polyacrylamide product solution are added in flocculation tank and carry out flocculation reaction, mud is 10 ~ 30 minutes in the flocculation tank residence time, then pressure filter is imported, in pressure filter, complete preliminary mummification processed, the sewage of generation is discharged by the rising pipe in pressure filter;

4. the mud through step 3 gained is entered into mud squeezing passage, mud enters into pressure by mud squeezing passage and works in coordination with electroosmotic dewatering device, trigger pressure is worked in coordination with electroosmotic dewatering device and is carried out sludge dewatering, the gradient scope that pressure works in coordination with electroosmotic dewatering DC electric field is 0.5 ~ 3.6V/mm, the water ratio of the mud cake produced after sludge dewatering is 15% ~ 30%, and the thickness of mud cake is 5mm ~ 20mm.

Further, the moisture percentage in sewage sludge in above-mentioned steps 3 after pressure filter processed is 55% ~ 65%.

Further, described mud cake is transported in incinerating kiln by transport unit, to mud cake as a supplement fuel burn.

Further, described pressure filter is plate and frame(type)filter press or belt filter press.

Beneficial effect of the present invention is: sludge drying process of the present invention, it is by adopting pressure filter desiccating method and osmosis desiccating method, and sludge drying process can more smooth and easyly be carried out easily, and sludge drying degree is more controlled, mud handling capacity is larger, and without causing the anxiety of secondary pollution.Specifically, namely before the mud high to water ratio carries out drying and other treatment, first pre-treatment is carried out to it, mud drops in microwave heating appts and carries out broken wall, virus killing and sterilizing, its water ratio is adjusted to the scope being convenient to sludge drying device process, sludge dewatering is carried out again by pressure filter, then re-use pressure to work in coordination with electroosmotic dewatering device and carry out second dehydration to it, after second dehydration, the sludge cake of output carries out burning disposal by incineration system, completely eliminate the hidden danger that sludge drying process may cause secondary pollution, avoid the stench that high temperature produces, the obnoxious flavoures such as the Dioxins that high temperature incineration produces.

Embodiment

Embodiment: get 100 jin, the mud that water ratio is 75% ~ 85%, mud is dropped in microwave heating appts and carry out broken wall, virus killing and sterilizing, the amount of adding cationic polyacrylamide flocculant agent is 5% of primary mud, add in the dissolver of band stirring and heating measures uniformly at leisure, the whipping appts using per minute to transfer 60 ~ 200 turns to carries out stirring 30 minutes, and mechanical shearing excessively acute for a long time should be avoided, mud in sewage sludge storage case and cationic polyacrylamide product solution are added in flocculation tank and carries out flocculation reaction, mud is 10 ~ 30 minutes in the flocculation tank residence time, then pressure filter is imported, preliminary mummification processed is completed in pressure filter, the sewage produced is discharged by the rising pipe in pressure filter, the mud of gained is entered into mud squeezing passage, mud enters into pressure by mud squeezing passage and works in coordination with electroosmotic dewatering device, trigger pressure is worked in coordination with electroosmotic dewatering device and is carried out sludge dewatering, the gradient scope that pressure works in coordination with electroosmotic dewatering DC electric field is 0.5 ~ 3.6V/mm, the water ratio of the mud cake produced after sludge dewatering is 15% ~ 30%, the thickness of mud cake is 5mm ~ 20mm.

Above one embodiment of the present of invention have been described in detail, but described content being only preferred embodiment of the present invention, can not being considered to for limiting practical range of the present invention.All equalizations done according to the present patent application scope change and improve, and all should still belong within patent covering scope of the present invention.

Claims

1. a drying process for low water-bearing section mud, comprises the following steps:

1). the pre-treatment of water-containing sludge: mud is dropped in microwave heating appts and carry out broken wall, virus killing and sterilizing.By the water ratio after sterilizing be 75% ~ 85% mud add sewage sludge storage case store;

2). cationic polyacrylamide flocculant agent added at leisure uniformly in the dissolver of band stirring and heating measures, the whipping appts using per minute to transfer 60 ~ 200 turns to stirs, and should avoid mechanical shearing excessively acute for a long time;

3). the mud in sewage sludge storage case and cationic polyacrylamide product solution are added in flocculation tank and carries out flocculation reaction, mud is 10 ~ 30 minutes in the flocculation tank residence time, then pressure filter is imported, in pressure filter, complete preliminary mummification processed, the sewage of generation is discharged by the rising pipe in pressure filter;

4). the mud through step 3 gained is entered into mud squeezing passage, mud enters into pressure by mud squeezing passage and works in coordination with electroosmotic dewatering device, trigger pressure is worked in coordination with electroosmotic dewatering device and is carried out sludge dewatering, the gradient scope that pressure works in coordination with electroosmotic dewatering DC electric field is 0.5 ~ 3.6V/mm, the water ratio of the mud cake produced after sludge dewatering is 15% ~ 30%, and the thickness of mud cake is 5mm ~ 20mm.

2. the drying process of a kind of low water-bearing section mud according to claim 1, is characterized in that: the moisture percentage in sewage sludge in above-mentioned steps 3 after pressure filter processed is 55% ~ 65%.

3. the drying process of a kind of low water-bearing section mud according to claim 1, is characterized in that: described mud cake is transported in incinerating kiln by transport unit, to mud cake as a supplement fuel burn.

4. the drying process of a kind of low water-bearing section mud according to claim 1, is characterized in that: described pressure filter is plate and frame(type)filter press or belt filter press.