阅读说明：本技术 一种工业污泥连续干燥与无害化处理方法 (Continuous drying and harmless treatment method for industrial sludge ) 是由 林冲 陈学彬 陈秋丽 陈嘉澍 黄桂颖 卓献荣 于 2021-09-10 设计创作，主要内容包括：一种工业污泥连续干燥与无害化处理方法,包括以下步骤：工业原污泥从储存的污泥桶中输出,进行过滤,然后传送至进料口内,然后通过推送装置来传输污泥；在传输装置内部设有载热介质循环通道,通过加入载热介质对污泥进行干燥脱水；在推送装置表面设有排气口,通过排气口来降低推送装置在运行过程中产生的压力,然后将排出的气体进行冷却冷凝处理；在污泥脱水干燥完成后通过焚烧炉来进行焚烧,焚烧完成后进行收集；通过在推送装置内加入载热介质进行热循环,使污泥脱水干燥的效果更佳；通过冷凝系统可以将排出的气体进行处理收集以及进行无害化处理；通过采用热交换的方式来收集热量供于其他步骤,形成循环利用,使能源利用最大化。(A continuous drying and harmless treatment method for industrial sludge comprises the following steps: outputting industrial raw sludge from a stored sludge barrel, filtering, conveying the industrial raw sludge into a feed inlet, and conveying the industrial raw sludge through a pushing device; a heat-carrying medium circulation channel is arranged in the transmission device, and sludge is dried and dehydrated by adding the heat-carrying medium; an exhaust port is arranged on the surface of the pushing device, the pressure generated by the pushing device in the operation process is reduced through the exhaust port, and then the exhausted gas is cooled and condensed; after the sludge is dehydrated and dried, incinerating the sludge by an incinerator, and collecting the sludge after the incineration is finished; a heat-carrying medium is added into the pushing device for thermal circulation, so that the sludge dewatering and drying effects are better; the discharged gas can be treated and collected and subjected to harmless treatment through a condensing system; the heat is collected by adopting a heat exchange mode and is supplied to other steps, so that the cyclic utilization is formed, and the energy utilization is maximized.)

1. A continuous drying and harmless treatment method for industrial sludge comprises the following steps:

s1, conveying industrial raw sludge: outputting industrial raw sludge from a stored sludge barrel (1), filtering, and then conveying the industrial raw sludge into a feeding hole (3);

s2, conveying sludge by a pushing device: the double screws (4) of the pushing device (2) are meshed to transmit industrial sludge, the meshing of the screws and the sludge generate friction in the sludge transmission process, and the sludge is dried and dehydrated through heat generated by the friction;

s3, dewatering the sludge through heat-carrying medium circulation heat supply: a heat-carrying medium circulation channel is arranged in the pushing device (2), and the pushing device (2) is circularly heated by adding the heat-carrying medium in the circulation channel, so that the sludge is dried and dehydrated more thoroughly in the transmission process;

s4, exhausting and reducing pressure: an exhaust port (9) is formed in the surface of the pushing device (2), and pressure generated by the pushing device (2) in the operation process is reduced through exhaust; the gas discharged from the gas outlet (9) comprises water vapor, VOC gas and non-condensable gas;

s5, cooling and condensing: cooling and condensing the gas discharged in the step S4 by a condensing system and performing a harmless treatment;

s6, incinerating the dehydrated and dried sludge: burning the industrial sludge dried and dehydrated in the step S3 in an incinerator (21);

s7, sludge collection: in the sludge incineration process, the generated gas is subjected to electrostatic dust removal and then discharged; and collecting the sludge after the sludge is incinerated.

2. The method for continuously drying and harmlessly treating industrial sludge according to claim 1, wherein the condensing system of step S5 comprises a positive pressure cooling condensing system, and the positive pressure cooling condensing system comprises an exhaust gas collecting pipe (10), a cooling water pipe (11), a condenser (12), a condensed water collecting pipe (13), and a condensed water collecting tank (14).

3. The method for continuously drying and harmlessly treating industrial sludge according to claim 1, wherein the condensation system of step S5 further comprises a negative pressure freezing and condensation system, and the negative pressure freezing and condensation system comprises a volatile component gas collection tank (15), a volatile component condenser (16), a vacuum pump (17), an evacuation port (18), a two-stage compression refrigerator (19), and a liquid volatile component collection tank (20).

4. The method for continuously drying and harmlessly treating industrial sludge according to claim 1, wherein the positive pressure cooling condensing system of the condensing system is used for continuously cooling and condensing water vapor discharged from the exhaust port (9) into condensed water, and then collecting the condensed water; the negative pressure freezing and condensing system of the condensing system is used for freezing and cooling the VOC gas discharged by the exhaust port (9) and condensing the VOC gas into liquid.

5. The method for continuously drying and harmlessly treating industrial sludge according to claim 2 or 3, wherein the step of treating the gas by the condensation system comprises the following steps:

s5.1, collecting gas: collecting the gas discharged by the pushing device (2) through an exhaust collecting pipe (10), and conveying the gas into a condenser (12);

s5.2, adding cooling water for condensation: cooling water is added into one end of the cooling water pipe (11) to cool the gas in the condenser (12) and condense the water vapor into liquid;

s5.3, collecting condensed water: conveying the condensed liquid to a condensed water collecting pool (14) through a condensed water collecting pipe (13) for centralized collection;

s5.4, collecting VOC gas and non-condensable gas: the residual VOC gas and non-condensable gas after positive pressure cooling and condensation treatment are collected into a volatile gas collection tank (15);

s5.5, condensing and collecting gas: conveying the gas in the volatile component gas collection tank (15) into a volatile component condenser (16) for freezing and cooling to condense the gas into liquid, and conveying the condensed liquid into a liquid volatile component collection tank (20) for storage;

s5.6, discharging non-condensable gas: the remaining non-condensable gas is discharged from the evacuation port (18) by a vacuum pump (17).

6. The method for continuously drying and harmlessly treating industrial sludge according to claim 1, wherein the step S6 further comprises the steps of:

s6.1, collecting energy sources: the heat exchange mode is adopted to collect the heat generated in the incinerator (21) during the incineration process of the sludge;

s6.2, recycling energy: and the collected heat energy is used for other steps to form a cycle, so that the energy utilization is maximized.

7. The method of claim 6, wherein the heat exchange of step S6.1 comprises a first heat exchange and a second heat exchange; the temperature collected by the first heat exchange is taken from a relatively high temperature in the incinerator (21), and the temperature collected by the second heat exchange is taken from a relatively low temperature in the incinerator (21).

8. The method of claim 7, wherein the high temperature collected by the first heat exchange is used in step S3; the low temperature collected by the second heat exchange is used for preheating the raw sludge in step S1.

Technical Field

The invention relates to the technical field of sludge treatment, in particular to a continuous drying and harmless treatment method for industrial sludge.

Background

Industrial sludge is a kind of sludge, and refers to a precipitated substance generated in an industrial wastewater treatment process. Industrial sludge is classified into general industrial sludge and hazardous waste sludge. Although industrial sludge is mainly inorganic sludge, it may contain a certain amount of pathogenic microorganisms, bacteria, heavy metal ions and persistent toxic and harmful substances such as organic solvents, and thus has a great hazard, and therefore, industrial sludge must be properly treated and disposed of, which has become a major problem in industrially developed areas for environmental protection. Currently, according to the properties of industrial sludge, the corresponding treatment process method of industrial sludge mainly comprises: concentrating, elutriating, filter pressing, vacuum filtering, drying, burying, burning, drying and the like.

Sludge drying is a process of removing most of water content from sludge through the action of percolation or evaporation, and generally refers to a drying facility which adopts a self-evaporation facility such as a sludge drying bed or a heat source such as steam, smoke, hot oil and the like. At present, in order to reduce drying energy consumption, dehydration (such as mechanical dehydration, positive-negative pressure difference filter pressing and the like) is almost adopted firstly, and then drying is carried out, wherein the drying method mainly comprises steam high-temperature drying, heat pump energy-saving drying and condensation of volatile matters in sludge in the drying process, so that the emission of waste gas (VOC) is reduced. The process method and the equipment are usually separated, the transportation of the raw sludge to the drying is usually open and discontinuous, secondary pollution is easy to cause, the treatment efficiency is low, and the treatment energy consumption and the economic cost are high. Based on the above, the invention provides a continuous drying and harmless treatment method for industrial sludge, so as to solve the above problems.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a continuous drying and harmless treatment method for industrial sludge, which can effectively solve the problems in the background art.

In order to solve the problems, the technical scheme adopted by the invention is as follows: a continuous drying and harmless treatment method for industrial sludge comprises the following steps:

s1, conveying industrial raw sludge: outputting industrial raw sludge from a stored sludge barrel, filtering, and conveying the industrial raw sludge into a feed inlet;

s2, conveying sludge by a pushing device: the double screws of the pushing device are meshed to transmit industrial sludge, friction is generated between the meshing of the screws and the sludge in the sludge transmission process, and the sludge is dried and dehydrated through heat generated by the friction;

s3, dewatering the sludge through heat-carrying medium circulation heat supply: a heat-carrying medium circulation channel is arranged in the pushing device, and the pushing device is circularly heated by adding the heat-carrying medium in the circulation channel, so that the sludge is dried and dehydrated more thoroughly in the transmission process;

s4, exhausting and reducing pressure: an exhaust port is arranged on the surface of the pushing device, and the pressure generated by the pushing device in the operation process is reduced through exhaust; the gas discharged from the gas outlet comprises water vapor, VOC gas and non-condensable gas;

s5, cooling and condensing: cooling and condensing the gas discharged in the step S4 by a condensing system and performing a harmless treatment;

s6, incinerating the dehydrated and dried sludge: burning the industrial sludge dried and dehydrated in the step S3 by an incinerator;

s7, sludge collection: in the sludge incineration process, the generated gas is subjected to electrostatic dust removal and then discharged; and collecting the sludge after the sludge is incinerated.

As a further preferable mode of the present invention, the condensing system of step S5 includes a positive pressure cooling condensing system, and the positive pressure cooling condensing system is composed of an exhaust gas collecting pipe, a cooling water pipe, a condenser, a condensed water collecting pipe, and a condensed water collecting tank.

As a further preferable scheme of the present invention, the condensing system of step S5 further includes a negative pressure freezing and condensing system, and the negative pressure freezing and condensing system is composed of a volatile component gas collecting tank, a volatile component condenser, a vacuum pump, an evacuation port, a two-stage compression refrigerator, and a liquid volatile component collecting tank.

As a further preferable scheme of the invention, the positive pressure cooling and condensing system of the condensing system is used for continuously cooling and condensing the water vapor discharged from the exhaust port into condensed water, and then collecting the condensed water; the negative pressure freezing and condensing system of the condensing system is used for freezing and cooling the VOC gas discharged by the exhaust port to condense the VOC gas into liquid.

As a further preferred embodiment of the present invention, the condensing system processes the gas by the following steps:

s5.1, collecting gas: collecting the gas discharged by the pushing device through an exhaust collecting pipe, and conveying the gas into a condenser;

s5.2, adding cooling water for condensation: cooling the gas in the condenser by adding cooling water into one end of the cooling water pipe, and condensing the water vapor in the gas into liquid;

s5.3, collecting condensed water: conveying the condensed liquid to a condensed water collecting pool through a condensed water collecting pipe for centralized collection;

s5.4, collecting VOC gas and non-condensable gas: collecting the residual VOC gas and non-condensable gas after positive pressure cooling condensation treatment into a volatile gas collection tank;

s5.5, condensing and collecting gas: conveying the gas in the volatile component gas collection tank to a volatile component condenser for freezing and cooling to condense the gas into liquid, and conveying the condensed liquid to a liquid volatile component collection tank for storage;

s5.6, discharging non-condensable gas: the remaining non-condensable gas is discharged from the evacuation port by a vacuum pump.

As a further preferable embodiment of the present invention, the step S6 further includes the steps of:

s6.1, collecting energy sources: the heat exchange mode is adopted to collect the heat generated in the incinerator during the incineration process of the sludge;

s6.2, recycling energy: and the collected heat energy is used for other steps to form a cycle, so that the energy utilization is maximized.

As a further preferable embodiment of the present invention, the heat exchange method of step S6.1 includes first heat exchange and second heat exchange; the temperature collected by the first heat exchange is taken from the relatively high temperature in the incinerator; the temperature collected by the second heat exchange is taken from the relatively low temperature in the incinerator.

As a further preferable aspect of the present invention, the high temperature collected by the first heat exchange is used in step S3; the low temperature collected by the second heat exchange is used for preheating the raw sludge in step S1.

Compared with the prior art, the invention provides a continuous drying and harmless treatment method for industrial sludge, which has the following beneficial effects:

a heat-carrying medium is added into the pushing device for thermal circulation, so that the sludge dewatering and drying effects are better; the discharged gas can be treated and collected and subjected to harmless treatment through a condensing system; the heat is collected by adopting a heat exchange mode and is supplied to other steps, so that the cyclic utilization is formed, and the energy utilization is maximized.

Drawings

FIG. 1 is a schematic view of the structure of each part of the present invention;

FIG. 2 is an overall flow chart of sludge drying according to the present invention;

wherein: 1. sludge barrel, 2, pusher, 3, feed inlet, 4, twin-screw, 5, motor, 6, speed reducer, 7, belt, 8, dry sludge outlet pipe, 9, exhaust port, 10, exhaust collecting pipe, 11, cooling water pipe, 12, condenser, 13, condensate collecting pipe, 14, condensate collecting tank, 15, volatile part gas collecting tank, 16, volatile part condenser, 17, vacuum pump, 18, evacuation port, 19, two-stage compression refrigerator, 20, liquid volatile collecting tank, 21, incinerator, 22, heat exchanger.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

Referring to fig. 1-2, the invention provides a continuous drying and harmless treatment method for industrial sludge, which comprises the following steps:

s1, conveying industrial raw sludge: outputting industrial raw sludge from a stored sludge barrel 1, filtering, and then conveying the industrial raw sludge into a feeding hole 3; the feeding hole 3 is formed in the front end of the pushing device 2, and the feeding hole 3 is communicated with the pushing device 2;

s2, conveying sludge by a pushing device: the double screws 4 of the pushing device 2 are meshed to transmit industrial sludge, the meshing of the screws and the sludge generate friction in the sludge transmission process, and the sludge is dried and dehydrated through heat generated by the friction; the double screw 4 is positioned in the pushing device 2, and a heat-carrying circulation channel is arranged in the double screw 3 and used for adding a heat-carrying medium to enable the screw to generate heat; the pushing device 2 is driven by a motor 5, a speed reducer 6 and a belt 7;

s3, dewatering the sludge through heat-carrying medium circulation heat supply: a heat-carrying medium circulation channel is arranged in the pushing device 2 and surrounds the shell of the pushing device 2, and the heat-carrying medium is added into the circulation channel to circularly heat the pushing device 2, so that the sludge is dried and dehydrated more thoroughly in the transmission process; the heat-carrying medium is heat-conducting oil or other media;

s4, exhausting and reducing pressure: an exhaust port 9 is arranged on the surface of the pushing device 2, and the pressure generated by the pushing device 2 in the operation process is reduced through exhaust; the gas discharged from the gas outlet 9 includes water vapor, VOC gas, and non-condensable gas;

s5, cooling and condensing: cooling and condensing the gas discharged in the step S4 by a condensing system and performing a harmless treatment;

s6, incinerating the dehydrated and dried sludge: burning the industrial sludge dried and dehydrated in the step S3 in an incinerator 21; a dried sludge outlet pipe 8 is arranged at the tail end of the pushing device 2, and after the industrial sludge is dried by the pushing device 2, the industrial sludge is discharged through the dried sludge outlet pipe 8 to be collected, and then is combusted by an incinerator 21;

s7, sludge collection: in the sludge incineration process, the generated gas is subjected to electrostatic dust removal and then discharged; and collecting the sludge after the sludge is incinerated.

As a further preferable mode of the present invention, the condensing system of step S5 includes a positive pressure cooling condensing system, and the positive pressure cooling condensing system is composed of an exhaust gas collecting pipe 10, a cooling water pipe 11, a condenser 12, a condensed water collecting pipe 13, and a condensed water collecting tank 14.

As a further preferable scheme of the present invention, the condensing system of step S5 further includes a negative pressure freezing and condensing system, and the negative pressure freezing and condensing system is composed of a volatile component gas collecting tank 15, a volatile component condenser 16, a vacuum pump 17, an evacuation port 18, a two-stage compression refrigerator 19, and a liquid volatile component collecting tank 20.

As a further preferable aspect of the present invention, the positive pressure cooling and condensing system of the condensing system is configured to continuously cool and condense water vapor discharged from the exhaust port 9 into condensed water, and then collect the condensed water; the negative pressure freezing and condensing system of the condensing system is used for freezing and cooling the VOC gas discharged from the gas outlet 9 to condense the VOC gas into liquid.

As a further preferred embodiment of the present invention, the condensing system processes the gas by the following steps:

s5.1, collecting gas: collecting the gas discharged by the pushing device 2 through an exhaust collecting pipe 10, and conveying the gas to a condenser 12;

s5.2, adding cooling water for condensation: cooling water is added into one end of the cooling water pipe 11 to cool the gas in the condenser 12, and the water vapor in the gas is condensed into liquid;

s5.3, collecting condensed water: conveying the condensed liquid to a condensed water collecting tank 14 through a condensed water collecting pipe 13 for centralized collection;

s5.4, collecting VOC gas and non-condensable gas: the residual VOC gas and non-condensable gas after positive pressure cooling and condensation treatment are collected into a volatile gas collection tank 15;

s5.5, condensing and collecting gas: conveying the gas in the volatile component gas collection tank 15 into a volatile component condenser 16 for freezing and cooling to condense the gas into liquid, and conveying the condensed liquid into a liquid volatile component collection tank 20 for storage for subsequent recovery or other harmless treatment;

s5.6, discharging non-condensable gas: the remaining non-condensable gas is discharged from the evacuation port 18 by the vacuum pump 17;

the vacuum pump 17 is used as a gas flow driving device, and a low vacuum pump, such as a liquid ring vacuum pump, can be selected, and is mainly used for pumping the residual non-condensable gas after the volatile component is frozen, cooled and condensed by the volatile component condenser 16, on one hand, the pressure of the gas side flow channel of the volatile component gas collection tank 15 and the volatile component condenser 16 is further reduced to a proper negative pressure, and on the other hand, the residual non-condensable gas is exhausted to the atmosphere through the exhaust port 18.

As a further preferable embodiment of the present invention, the step S6 further includes the steps of:

s6.1, collecting energy sources: collecting heat generated in the incineration furnace 21 during the incineration of the sludge by using a heat exchanger 22;

s6.2, recycling energy: and the collected heat energy is used for other steps to form a cycle, so that the energy utilization is maximized.

As a further preferable scheme of the present invention, the heat exchanger 22 of step S6.1 collects heat of the incinerator 21 and includes a first heat exchange collection temperature and a second heat exchange collection temperature; the temperature acquired by the first heat exchange is more than or equal to 100 ℃; the temperature collected by the second heat exchange is less than or equal to 100 ℃.

As a further preferable scheme of the present invention, the high temperature collected by the first heat exchange is used in step S3, so as to keep the pushing device 2 capable of continuously supplying heat during operation, and simultaneously reduce the heat load of the heat-carrying medium; the low temperature collected by the second heat exchange is used for preheating the industrial raw sludge in the sludge barrel 1 in the step S1; by preheating the industrial sludge, the load of the subsequent process can be reduced.

As a specific embodiment of the present invention:

filtering industrial raw sludge stored in the sludge barrel 1, then conveying the filtered industrial raw sludge to the feeding hole 3, and feeding the sludge into the pushing device 2 through the feeding hole 3; then starting a motor 5 and a speed reducer 6 to drive the double screws 4, driving the sludge to be conveyed forwards by the rotary meshing of the double screws 4, generating friction between the meshing of the double screws 4 and the sludge in the sludge conveying process, simultaneously adding a heat-carrying medium into a circulating channel of a shell of the pushing device 2 to carry out thermal circulation, and adding the heat-carrying medium into a heat-carrying circulating channel inside the double screws 4 to carry out thermal circulation.

In the sludge conveying process, as the sludge is heated, dried and dehydrated, a large amount of water vapor, VOC (volatile organic compound) gas and non-condensable gas can be generated in the pushing device 2; discharging the gases from an exhaust port 9 of the pushing device 2, entering an exhaust collecting pipe 10, then conveying the gases into a condenser 12 through the exhaust collecting pipe 10, simultaneously adding cooling water from one end of a cooling water pipe 11 into the condenser 12 for circulation, cooling the gases, condensing water vapor in the gases into liquid, and conveying the condensed liquid into a condensed water collecting pool 14 through a condensed water collecting pipe 13 for centralized collection and recycling; after positive pressure cooling and condensation treatment, collecting the residual VOC gas and non-condensable gas into a volatile component gas collecting tank 15, then conveying the volatile component gas and non-condensable gas into a volatile component condenser 16 for freezing and cooling, condensing the volatile component gas and non-condensable gas into liquid, conveying the liquid into a liquid volatile component collecting tank 20 for storage, and performing subsequent recycling or other harmless treatment; after freezing and condensation are completed, the remaining non-condensable gas is discharged from the evacuation port 18 to the atmosphere by the vacuum pump 17.

Discharging the sludge after dehydration and drying from a dried sludge outlet pipe 8 at the tail end of the pushing device 2 for collection, and then conveying the sludge into an incinerator 21 for combustion; in the combustion process, heat is collected through the heat exchanger 22, the heat is collected at a higher temperature for the first time and then is conveyed to the pushing device 2 for the sludge conveying process to utilize, the heat is collected at a lower temperature for the second time, and then the heat is conveyed into the sludge barrel 1 to preheat the industrial raw sludge in advance; in the sludge incineration process, the generated gas is subjected to electrostatic dust removal and then discharged; and collecting the sludge after the sludge is incinerated.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.