Method and device for stabilizing heavy metal through pyrolysis of sludge

A heavy metal and pyrolysis technology, applied in pyrolysis treatment of sludge, removal of solid waste, vaporization of by-products, etc., can solve the problems of high sludge treatment cost, waste of funds, large input level, etc., and reduce energy consumption. requirements and disposal costs, improve overall economics, avoid high disposal fees

Inactive Publication Date: 2014-03-26
TONGJI UNIV
View PDF4 Cites 20 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] However, in the existing sludge treatment technology, the role of stabilizing heavy metals of sludge pyrolysis carbon has not been brought into play
On the other hand, a large amount of hazardous waste containing heavy metals produced by various industries spends a lot of money on incineration or sent to high-level and expensive safe landfills for disposal, which not only wastes money, but also easily produces secondary waste. Pollution
[0004] In view of the fact that the existing sludge carbonization technology cannot meet the large-scale use of the heavy metal stabilization effect of sludge pyrolysis carbon to actively treat hazardous waste containing heavy metals, the sludge itself is expensive and expensive to treat; the cost of hazardous waste treatment is higher and the cost is higher. The present invention proposes an efficient, economical, feasible, non-increasing secondary pollution and saves disposal site and investment of various waste comprehensive treatment technologies, that is, a method and device for stabilizing heavy metals by using sludge pyrolysis, which can Disposal of sludge and simultaneous stabilization of heavy metals and hazardous waste containing heavy metals using the pyrolysis process of sludge

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method and device for stabilizing heavy metal through pyrolysis of sludge

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025]The dry basis calorific value of sewage sludge in a certain city is 15500KJ / kg, the water content is 82%, and the various heavy metals contained in itself are not high. Another batch of incineration fly ash needs to be processed. The incineration fly ash contains 2800ppm of Pb, 400ppm of Cd and 3.6ng / g-I TEQ of dioxin, which belongs to hazardous waste. During the treatment, fly ash is added according to 20% of the dry weight of the sludge, and the dry basis calorific value of the mixed material is 12400kJ / kg. And add 18kg of sawdust powder / ton of wet sludge; or add 7kg of crushed waste plastics per ton of wet sludge to supplement pyrolysis energy. After repeated mixing and kneading in the tank-type mixer 1 with agitator, it is sent to the dryer 2. The dryer 2 is a rotary drum dryer. The flue gas 9 is in direct contact with the sludge and dried. into the gas purifier 13. After drying, the mixed material 3 enters the pyrolyzer 4. The pyrolyzer 4 is a three-stage heating ...

Embodiment 2

[0027] The dry basis calorific value of a certain sewage sludge is 13000KJ / kg, the water content is 70%, and the various heavy metals contained in itself are not high. Another batch of Cr-containing waste slag discharged from chemical plants needs to be treated. The waste slag has a Cr concentration of 5900ppm, a Cd concentration of 1000ppm, a water content of 40%, and a dry basis calorific value of 5000kJ / kg, which is a hazardous waste. During treatment, add this waste residue according to 5%~10% of the dry weight of the sludge, and the dry basis calorific value of the mixed material is 10900~12600 KJ / kg. Repeated mixing in the tank type mixer 1 with agitator, after stirring evenly, it is sent to the dryer 2, the dryer 2 is a rotary drum dryer, the flue gas 9 is in direct contact with the sludge and dried, and the waste gas is discharged into the gas Purifier 13. After drying, the mixture 3 enters the pyrolyzer 4 again. The form of the pyrolyzer 4 is the same as that of embo...

Embodiment 3

[0029] The dry basis calorific value of a certain sewage sludge is 12000KJ / kg, it has been dried, the moisture content is nearly 0%, and the various heavy metals contained in it are not high. Another batch of sludge containing heavy metal cadmium Cd needs to be treated; the dry basis calorific value of the cadmium-containing sludge is about 3000KJ / kg, which cannot sustain combustion, the concentration of Cd is 2900ppm (dry basis), and the water content is 60%. Hazardous Waste. During treatment, add this waste residue according to 5%~10% of the dry weight of the sludge, and the dry basis calorific value of the mixed material is 11100~11550 KJ / kg. Add a small amount of water to the tank-type mixer 1 with agitator to thicken the dry sludge, mix it with cadmium-containing mud repeatedly, and after mixing evenly, send it to the dryer 2. The dryer adopts a rotary disc-type indirect dryer. , the dried material 3 is sent to the pyrolyzer 4, the pyrolyzer is a three-stage rotary heati...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
heating valueaaaaaaaaaa
heating valueaaaaaaaaaa
heating valueaaaaaaaaaa
Login to view more

Abstract

The invention relates to a method and a device for stabilizing heavy metal through pyrolysis of sludge. The method comprises the following steps: uniformly mixing dewatered sludge with moisture content of 0%-80% with hazardous waste containing heavy metal needing to be processed, wherein the dry basis heat value of the mixed material is guaranteed not less than 9000kJ/kg; drying the sludge mixed with hazardous waste containing heavy metal, then putting into a pyrolyzer for pyrolysis at 350-750 DEG C, preferably, at 450-650 DEG C; online burning the volatile components generated in pyrolysis so as to offer heat required by the pyrolyzer, wherein the formed cokes are cooled down and then sent to a sanitary landfill or are reused as catalyst. The device for stabilizing heavy metal through pyrolysis of sludge comprises a mixer for sludge and hazardous waste containing heavy metal, a dryer for drying mixture of sludge and hazardous waste containing heavy metal, the pyrolyzer, a gas storage tank and a combustion chamber for pyrolyzing volatile components, as well as a cooler for pyrolyzing carbon. The method and the device for stabilizing heavy metal through pyrolysis of sludge have the advantages that hazardous waste containing heavy metal and other contaminants can be processed while in sludge pyrolysis, and extra cost for investment and processing is not increased.

Description

technical field [0001] The invention belongs to the field of sludge disposal and resource treatment. Specifically, the present invention relates to a method and device for stabilizing non-volatile heavy metals by using sludge pyrolysis. Background technique [0002] Sewage treatment plants will produce a large amount of sludge in the process of treating sewage, mainly microbial residues, organic pollutants and some inorganic impurities. The sludge output of urban sewage treatment plants is about 1% of the sewage volume, and the sludge contains 97% water. Processing 100,000 M per day 3 Sewage plant with a daily sludge output of 1000M 3 Sludge (water content 97%). The moisture content of the dewatered sludge formed after sludge dehydration is generally at 80%, and the advanced dehydration technology in the existing technology can reduce the moisture content to 70%~65%. The annual sludge generation in my country's cities is nearly 30 million tons (based on a moisture conte...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C02F11/10B09B3/00
CPCY02W10/40
Inventor 戴晓虎陈德珍薛香玉窦晓敏
Owner TONGJI UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap