阅读说明：本技术 一种污泥多级资源化的综合利用方法及其利用系统 (Comprehensive utilization method and system for multistage recycling of sludge ) 是由 陈琛 罗海林 蔡素燕 汪元南 吴艳丽 王敏 于 2019-10-16 设计创作，主要内容包括：一种污泥多级资源化的综合利用方法及其利用系统。所述方法包括包括以下步骤：(1)污泥前期处理；(2)污泥和热烟气的热解；(3)油气分离；(4)资源化利用；(5)制得资源化成品。所述利用系统包括污泥处理和输送装置、热解反应装置、油气分离装置、窑炉、污泥焦资源化处理装置、成品装置和自动控制装置,所述自动控制装置控制上述其它装置工作。本发明能够实现高效、节能、无污染的污泥资源化处理。(A comprehensive utilization method and a comprehensive utilization system for multi-stage recycling of sludge. The method comprises the following steps: (1) sludge pretreatment; (2) pyrolysis of sludge and hot flue gas; (3) oil-gas separation; (4) resource utilization; (5) and obtaining a resource finished product. The utilization system comprises a sludge treatment and conveying device, a pyrolysis reaction device, an oil-gas separation device, a kiln, a sludge coke recycling device, a finished product device and an automatic control device, wherein the automatic control device controls the other devices to work. The invention can realize the sludge resource treatment with high efficiency, energy saving and no pollution.)

1. The comprehensive utilization method of the sludge multi-stage resource is characterized by comprising the following steps:

(1) sludge pretreatment: adding polyferric sulfate into the sludge to destroy floc structures in the sludge, wherein the adding amount of the polyferric sulfate is 5-7% of the total mass of the sludge, and then dehydrating; adsorbing impurities in odor released in the sludge dehydration process by using natural zeolite or artificial zeolite, and discharging the tail gas after adsorption up to the standard;

(2) pyrolysis of sludge and hot flue gas: carrying out concurrent flow contact on the hot flue gas from the kiln and the sludge treated in the step (1), and pyrolyzing sludge particles to generate tar, pyrolysis gas and sludge coke under the anoxic condition by absorbing heat;

(3) oil-gas separation: separating oil gas generated by pyrolysis, wherein the separated pyrolysis gas flows out to pass through a dust removal unit and then is used as fuel and gas denitration agent and is sent into a furnace chamber reburning area of a kiln; the separated tar is conveyed to a sewage treatment unit for treatment;

(4) resource utilization: recycling the sludge coke generated in the step (2), and adding cement and fly ash into the sludge coke, wherein the mass ratio of the cement to the fly ash to the sludge coke is 2-3: 4-5: 10-12; stirring, crushing and mixing at a stirring speed of 3800-4200 r/min for 1-2 h, inputting the mixture into an aging bin for aging, and keeping the temperature in the aging bin at 50-52 ℃ for 2-3 h to obtain an aged material;

(5) preparing a resource finished product: introducing the aged material into a mold, placing the mold in a press machine, keeping the molding pressure at 22-25 Mpa at the highest pressure for 30-35 s, releasing the pressure, unloading the mold, and taking out a brick blank; and (5) air-drying the green bricks, and spraying water for natural curing for 10-20 days to obtain the finished brick.

2. The comprehensive utilization method of the multistage resource of the sludge as claimed in claim 1, wherein the dehydration treatment in the step (1) is specifically that the sludge is pumped to a sludge dehydrator through a spiral sludge pump, the sludge is dehydrated to below 50% in an intensified manner, and a treating agent is added into filtrate after filter pressing dehydration so as to perform precipitation adsorption treatment on heavy metals; the treating agent comprises the following materials in parts by weight: 50-55 parts of polyaluminium, 10-15 parts of ferric chloride and 10-12 parts of sodium silicate, wherein the adding amount of the treating agent is 125-130 g/m³。

3. The comprehensive utilization method for multistage sludge resource utilization according to claims 1-2, characterized in that the temperature of hot flue gas in the step (2) is 480-520 ℃, and the oxygen content is 3-5%; the pyrolysis reaction temperature is 550-580 ℃; the grain diameter of the sludge particles is 0.5-0.8 mm.

4. The comprehensive utilization method of sludge multi-stage resource utilization according to claim 3, characterized in that the mixed gas of pyrolysis gas and flue gas in the step (3) is sent into a furnace chamber reburning area of a kiln, the temperature is 980-1000 ℃, and the air excess coefficient is 0.8-0.9.

5. The comprehensive utilization method of sludge multi-stage resource utilization according to claims 1-4, characterized in that in the step (4), after stirring, crushing and mixing and before the mixed material is input into the aging bin, the sludge is continuously extruded by the reducing screw auger, the sludge at the outlet of the reducing screw auger is extruded and heated, and the sludge leaving the outlet of the reducing screw auger is in a loose state.

6. The comprehensive utilization method of multistage sludge resources as claimed in claim 5, wherein in step (2), hot flue gas from the kiln firstly passes through a multistage cyclone processor to settle coarse particles with the diameter of more than 10 μm, and then passes through a bag-type dust collector, so that the interception rate of fine particles with the diameter of 1-10 μm reaches 99.9%.

7. A utilization system for executing a comprehensive utilization method for multistage resource utilization of sludge is characterized by comprising a sludge treatment and conveying device, a pyrolysis reaction device, an oil-gas separation device, a kiln, a sludge coke resource treatment device, a finished product device and an automatic control device, wherein the automatic control device controls the other devices to work;

the device comprises a sludge treatment and conveying device, a pyrolysis reaction device, a sludge coke recycling device and a finished product device which are sequentially connected, wherein the pyrolysis reaction device is also connected with an oil-gas separation device; a sludge conveying pipeline is arranged between the sludge treatment and conveying device and the pyrolysis reaction device, a first pyrolysis gas conveying pipe is arranged between the pyrolysis reaction device and the oil-gas separation device, a flue gas conveying pipe is arranged between the kiln and the pyrolysis reaction device, the pyrolysis reaction device is also provided with a sludge coke outlet, the sludge coke outlet is connected to the sludge coke recycling treatment device, a dust removal unit and a pyrolysis gas injection unit are arranged in the oil-gas separation device, a second pyrolysis gas conveying pipe is arranged between the dust removal unit and the pyrolysis gas injection unit, the pyrolysis gas injection unit is provided with a spray gun, the spray gun is positioned in a hearth of the kiln, and the dust removal; the sludge coke recycling treatment device is provided with an outlet which is connected with a finished product device.

8. The utilization system of claim 7, wherein the sludge treatment and delivery device is internally provided with a sludge dewatering machine, which comprises a power supply, an anode screw shaft, a fixed ring, a movable ring, a pore plate, a rotary cutter and a fiber mesh conveying belt.

Technical Field

The invention relates to the technical field of sludge treatment, in particular to a comprehensive utilization method and a comprehensive utilization system for multistage recycling of sludge.

Background

The sludge treatment aims at reduction, stabilization, harmlessness and final recycling, is convenient for transportation and consumption, and can recycle polluted resources. In the current various treatment methods, the input cost is respectively landfill, digestion and utilization, synergistic incineration and the like from low to high.

The sanitary landfill disposal does not meet the requirement of the current sludge disposal policy of the state, after the sludge is buried, the interior of the sludge still contains a large amount of water, a large amount of landfill leachate is generated, the local water source is polluted improperly treated, a large amount of land area is occupied, and the sludge landfill tends to be cancelled in the future.

The digestion is divided into anaerobic digestion and aerobic digestion, and finally the sludge can be used for preparing fertilizer for land utilization. Anaerobic digestion can not thoroughly treat all sludge at one time, the digestion process hardly meets the requirement of sludge harmlessness, high-temperature pyrohydrolysis is usually required before anaerobic digestion, the anaerobic biogas production process and biogas storage have safety risks, the organic matter content of domestic sludge is low, the sand content is high, the fertilizer content hardly meets the fertilizer making requirement, the fertilizer has a marketing problem, and through the pyrohydrolysis, anaerobic and aerobic processes, the investment is large, the operation cost is high, and the wastewater, odor and heavy metals exceed the standard and are difficult to treat.

The incineration process has obvious advantages in the aspects of sludge reduction and harmlessness, the sterilization effect is thorough, the moisture content of the sludge is reduced as far as possible before the sludge is incinerated, the heat value of the sludge is improved, a common incineration device is integrated with the drying process of the sludge, the one-time investment of treatment equipment is large, the energy consumption and the treatment cost are high, and heavy metals and the like after the sludge is incinerated can enter the atmosphere along with the diffusion of smoke dust to cause secondary pollution.

How to use a treatment process, achieve the reduction, stabilization, harmlessness and final resource utilization of the sludge with less investment and convenient operation is a problem which needs to be solved urgently.

Disclosure of Invention

In order to solve the problems, the invention provides a comprehensive utilization method and a comprehensive utilization system for multistage resource utilization of sludge. The invention can realize the sludge resource treatment with high efficiency, energy saving and no pollution.

The technical scheme adopted by the invention for solving the technical problems is a comprehensive utilization method for multistage resource of sludge, which comprises the following steps:

(1) sludge pretreatment: adding polyferric sulfate into the sludge to destroy floc structures in the sludge, wherein the adding amount of the polyferric sulfate is 5-7% of the total mass of the sludge, and then dehydrating; adsorbing impurities in odor released in the sludge dehydration process by using natural zeolite or artificial zeolite, and discharging the tail gas after adsorption up to the standard;

(2) pyrolysis of sludge and hot flue gas: carrying out concurrent flow contact on the hot flue gas from the kiln and the sludge treated in the step (1), and pyrolyzing sludge particles to generate tar, pyrolysis gas and sludge coke under the anoxic condition by absorbing heat;

(3) oil-gas separation: separating oil gas generated by pyrolysis, wherein the separated pyrolysis gas flows out to pass through a dust removal unit and then is used as fuel and gas denitration agent and is sent into a furnace chamber reburning area of a kiln; the separated tar is conveyed to a sewage treatment unit for treatment;

(4) resource utilization: performing resource utilization on the sludge coke generated in the step (2), and adding cement and fly ash into the sludge coke, wherein the mass ratio of the cement to the fly ash to the sludge coke is 2-3: 4-5: 10-12; stirring, crushing and mixing at a stirring speed of 3800-4200 r/min for 1-2 h, inputting the mixture into an aging bin for aging, and keeping the temperature in the aging bin at 50-52 ℃ for 2-3 h to obtain an aged material;

(5) preparing a resource finished product: introducing the aged material into a mold, placing the mold in a press machine, keeping the molding pressure at 22-25 Mpa at the highest pressure for 30-35 s, releasing the pressure, unloading the mold, and taking out a brick blank; and (5) air-drying the green bricks, and spraying water for natural curing for 10-20 days to obtain the finished brick.

Preferably, the dehydration treatment in the step (1) is specifically that the sludge is pumped to a sludge dehydrator through a spiral sludge pump, the sludge is dehydrated to below 50% in an intensified manner, and a treating agent is added into filtrate after filter pressing dehydration so as to carry out precipitation adsorption treatment on heavy metals; the treating agent comprises the following materials in parts by weight: 50-55 parts of polyaluminium, 10-15 parts of ferric chloride and 10-12 parts of sodium silicate, wherein the adding amount of the treating agent is 125-130 g/m³。

In any of the above schemes, preferably, the temperature of the hot flue gas in the step (2) is 480-520 ℃, and the oxygen content is 3-5%; the pyrolysis reaction temperature is 550-580 ℃; the grain diameter of the sludge particles is 0.5-0.8 mm.

In any of the above schemes, preferably, the mixed gas of the pyrolysis gas and the flue gas in the step (3) is sent into a furnace chamber reburning area of the kiln, the temperature is 980-1000 ℃, and the air excess coefficient is 0.8-0.9.

In any of the above schemes, preferably, in the step (4), after stirring, crushing and mixing and before the mixed material is input into the aging bin, the sludge is continuously extruded by the reducing screw auger, the sludge at the outlet of the reducing screw auger reaches the extrusion temperature rise, and the sludge leaving the outlet of the reducing screw auger is in a loose state.

In any of the above schemes, preferably, in the step (2), the hot flue gas from the kiln firstly passes through a multi-stage cyclone processor to settle coarse particles with the diameter of more than 10 μm, and then passes through a bag-type dust collector, so that the interception rate of fine particles with the diameter of 1-10 μm reaches 99.9%.

The invention adopts another technical scheme to solve the technical problems and is a multistage recycling utilization system for sludge, which comprises a sludge treatment and conveying device, a pyrolysis reaction device, an oil-gas separation device, a kiln, a sludge coke recycling treatment device, a finished product device and an automatic control device, wherein the automatic control device controls the other devices to work;

the device comprises a sludge treatment and conveying device, a pyrolysis reaction device, a sludge coke recycling device and a finished product device which are sequentially connected, wherein the pyrolysis reaction device is also connected with an oil-gas separation device; a sludge conveying pipeline is arranged between the sludge treatment and conveying device and the pyrolysis reaction device, a first pyrolysis gas conveying pipe is arranged between the pyrolysis reaction device and the oil-gas separation device, a flue gas conveying pipe is arranged between the kiln and the pyrolysis reaction device, the pyrolysis reaction device is also provided with a sludge coke outlet, the sludge coke outlet is connected to the sludge coke recycling treatment device, a dust removal unit and a pyrolysis gas injection unit are arranged in the oil-gas separation device, a second pyrolysis gas conveying pipe is arranged between the dust removal unit and the pyrolysis gas injection unit, the pyrolysis gas injection unit is provided with a spray gun, the spray gun is positioned in a hearth of the kiln, and the dust removal; the sludge coke recycling treatment device is provided with an outlet which is connected with a finished product device.

Preferably, a sludge dewatering machine is arranged in the sludge treatment and conveying device and comprises a power supply, an anode screw shaft, a fixed ring, a movable ring, a pore plate, a rotary cutter and a fiber mesh conveying belt.

The invention is obtained according to years of practical application practice and experience, adopts the best technical means and measures to carry out combined optimization, obtains the optimal technical effect, is not simple superposition and splicing of technical characteristics, and has obvious significance.

The invention has the beneficial effects that:

1. the comprehensive utilization method and the comprehensive utilization system for multistage recycling of sludge can realize continuous dehydration of sludge, and facilitate the recycling of prepared sludge fuel particles in various ways.

2. The invention takes the flue gas generated by the kiln as a heat source and a carrier gas, pyrolyzes the sludge at a certain temperature, removes NOx in the flue gas while realizing energy utilization, realizes the safe and resource utilization of the sludge, avoids the problem of secondary pollution of the existing disposal modes such as sludge landfill, incineration and the like, realizes the waste control by waste and the cooperative control of various pollutants, and is a feasible sludge resource utilization mode.

3. The industrial scale sludge systematic resource utilization process provided by the invention can be used for preparing the sludge into bricks, and has high process stability.

4. The invention has simple treatment method, short process flow and low treatment cost. The processing device has compact structure, good operation stability and reliability and no pollution in the processing process. Especially, the energy consumption in the treatment process is low, the treatment cost is reduced, and the popularization is facilitated.

Brief description of the drawings

FIG. 1 is a flow process diagram of a comprehensive utilization method of sludge multi-stage resource utilization according to the invention.

Detailed Description

The invention is further described with reference to the drawings and the detailed description, but the scope of the claims is not limited thereto.