CN117029005A - System for coal fired boiler coprocessing oily sludge - Google Patents

Abstract

The invention discloses a system for cooperatively treating oily sludge by a coal-fired boiler, which relates to the field of oily sludge treatment, and comprises a biomass gasifier, a low-nitrogen burner, a hot blast stove, a pyrolysis rotary kiln and the coal-fired boiler; the biomass gasification furnace, the low-nitrogen burner, the hot blast stove, the pyrolysis rotary kiln and the coal-fired boiler are sequentially connected through pipelines; the biomass gasification furnace is provided with a biomass inlet, the pyrolysis rotary kiln is provided with a feed inlet, and the pyrolysis rotary kiln is provided with a slag discharge port. The invention utilizes the coal-fired boiler to cooperatively treat the oily sludge, solves the problem of coal mill blockage caused by direct blending of coal into the oily sludge and influences the operation of the coal-fired boiler, is suitable for the treatment of the oily sludge with various properties, improves the cooperative treatment capacity of the coal-fired boiler, and greatly reduces the influence on the operation of the coal-fired boiler.

Description

System for coal fired boiler coprocessing oily sludge

Technical Field

The invention relates to the field of oily sludge treatment, in particular to a system for cooperatively treating oily sludge by a coal-fired boiler.

Background

The oily sludge is mainly oily solid waste generated in the links of crude oil exploitation, gathering and transportation, refining, oily sewage treatment and the like, and is one of main pollutants generated in the oil gas development and storage and transportation processes. The oil-containing sludge is not only waste generated in the oilfield production process, but also resource, and if the oil-containing sludge is not treated or recycled, the environment is polluted, and the resource waste is caused.

Aiming at the treatment of the oily sludge, more technologies such as incineration, pyrolysis, landfill, tempering and washing and the like are applied at present in China. The adoption of the coal-fired boiler to blend and burn the oil-containing sludge has the advantages of playing the synergic advantages of the coal-fired boiler, reducing investment, realizing the energy utilization of the oil-containing sludge, and eliminating the pollution of the oil-containing sludge to the environment.

For example, chinese patent publication No. CN113698069a discloses a co-treatment system and method for oil-containing sludge in coal-fired power plants, which adopts a process route of "centrifugal degreasing + residue co-firing", to heat and condition oil stains twice, and to screen the products obtained by the first heating and conditioning in a screening machine, and to screen the oversize product with low oil content in a scraper conveyor as fuel coal to recover heat thereof by co-firing, and to secondarily heat and condition undersize product with high oil content. The oil, mud and water of the oily sludge are efficiently separated in a two-stage centrifugal mode, and the oil phase obtained by secondary centrifugation is used as fuel oil of a power plant starting boiler or other types of fuel boilers, so that the fuel cost of the power plant is effectively reduced. And (5) the water phase obtained by secondary centrifugation enters a sewage treatment system.

The method has the following defects that the oily sludge is directly mixed into the coal as fuel for blending combustion:

1. the viscosity of the mixed oil-containing sludge is high, and the coal mill is easy to be blocked.

2. The oily sludge is pyrolyzed in the coal mill, and generated pyrolysis gas has potential safety hazard to the operation of the coal mill.

3. Because the property difference between the oil-containing sludge and the coal is large, the working condition of the coal-fired boiler is influenced.

Therefore, development of a technology suitable for the cooperative treatment of the oil-containing sludge of the coal-fired boiler can reduce the influence on the operation of the coal-fired power plant to the greatest extent, and the development of the cooperative treatment technology of the coal-fired boiler can be facilitated.

Disclosure of Invention

Based on the problems, the invention aims to provide a system for cooperatively treating oil-containing sludge of a coal-fired boiler, which is used for reducing the influence of oil-containing sludge with different properties on the operation of the coal-fired boiler, realizing the maximum energy utilization of the oil-containing sludge and eliminating the influence of the oil-containing sludge on the environment.

The invention provides the following scheme:

a system for cooperatively treating oily sludge by a coal-fired boiler comprises a biomass gasifier, a low-nitrogen combustor, a hot blast stove, a pyrolysis rotary kiln and the coal-fired boiler; the biomass gasification furnace, the low-nitrogen burner, the hot blast stove, the pyrolysis rotary kiln and the coal-fired boiler are sequentially connected through pipelines; the biomass gasification furnace is provided with a biomass inlet, the pyrolysis rotary kiln is provided with a feed inlet, and the pyrolysis rotary kiln is provided with a slag discharge port.

Further, the slag cooler is connected with the slag discharging port and is connected with the low-nitrogen burner through a pipeline. The slag cooler cools the slag discharged from the pyrolysis rotary kiln through air, the air is heated into high-temperature air under the action of the slag, and the high-temperature air is sent into the low-nitrogen combustor through the second air blower to be combusted.

Further, the pyrolysis rotary kiln comprises a cyclone dust collector which is arranged on a pipeline between the pyrolysis rotary kiln and the coal-fired boiler.

Further, the slag discharging port is arranged at one end close to the hot blast stove, and the feeding port is arranged at one end close to the cyclone dust collector.

Further, one end, close to the hot blast stove, of the pyrolysis rotary kiln is inclined downwards by 2-3 degrees.

Further, a burner is arranged on the coal-fired boiler, and the cyclone dust collector is connected with the burner through a pipeline.

Further, a first gas fan is arranged on a pipeline connected with the biomass gasifier and the low-nitrogen burner; a second gas fan is arranged on the pipeline between the cyclone dust collector and the coal-fired boiler.

Further, the biomass gasification furnace is connected with a first air blower; a second air blower is arranged on a pipeline connected with the low-nitrogen combustor of the slag cooler; the burner is connected with a third air blower.

Preferably, the biomass gasification furnace is an updraft fixed bed gasification furnace.

Preferably, the pyrolysis rotary kiln is an internal heating rotary kiln.

Further, the biomass inlet is arranged above the biomass gasification furnace.

Further, a material level gauge is arranged in the biomass gasification furnace.

Further, a biomass transport mechanism is also included.

Further, the device also comprises an oily sludge storage bin and an oily sludge conveying mechanism.

The invention also provides a method for cooperatively treating the oily sludge by the coal-fired boiler, which comprises the following steps:

s1: gasifying biomass into biomass fuel gas in a biomass gasification furnace;

s2: after being mixed with preheated air by a low-nitrogen burner, biomass fuel gas is fully combusted in a hot blast stove, and obtained high-temperature flue gas is introduced into a pyrolysis rotary kiln to fully contact with oily sludge, and oil and water in the oily sludge are gasified under the action of the high-temperature flue gas;

s3: and the gas discharged from the pyrolysis rotary kiln is sent into a coal-fired boiler for combustion after dust removal.

The invention has the following effects:

(1) The invention can treat oily sludge with different properties, such as oily sludge with higher viscosity, higher oil content, uneven particle size and impurities.

(2) The invention can greatly improve the quantity of the oil-containing sludge cooperatively treated by the coal-fired boiler, and avoids the blockage of a coal mill caused by the excessive oil-containing sludge because the oil-containing sludge is not directly mixed into the coal.

(3) The invention converts the oily sludge into pyrolysis gas to be sent into the coal-fired boiler for combustion and utilization, and reduces the influence of the treatment of the oily sludge on the coal-fired boiler to the greatest extent.

(4) The invention can realize the independent collection and disposal of the dregs after the pyrolysis of the oily sludge, and avoid the inorganic matters in the oily sludge from being mixed with the coal cinder discharged by the coal-fired boiler.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a flow chart of a system for cooperatively treating oil-containing sludge in a coal-fired boiler according to an embodiment of the invention.

Fig. 2 is a schematic diagram of a system for cooperatively treating oil-containing sludge in a coal-fired boiler according to an embodiment of the invention.

The figure identifies the description:

1-feeding bin, 2-first chain-plate conveyor, 3-bucket elevator, 4-second chain-plate conveyor, 5-buffer bin, 6-biomass gasifier, 7-first blower, 8-first gas fan, 9-low nitrogen burner, 10-second blower, 11-hot blast stove, 12-oily sludge storage bin, 13-large inclination angle conveyor, 14-screw conveyor, 15-pyrolysis rotary kiln, 16-slag cooler, 17-cyclone dust collector, 18-second gas fan, 19-burner, 20-third blower, 21-coal fired boiler, 22-pneumatic gate valve.

Detailed Description

The technical solutions of the present invention will be clearly and completely described in the following embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be understood that the terms "comprises" and "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

In the description of the present invention, it should be noted that, directions or positional relationships indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., are directions or positional relationships based on those shown in the drawings, or are directions or positional relationships conventionally put in use of the inventive product, are merely for convenience of describing the present invention and simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific direction, be constructed and operated in a specific direction, and thus should not be construed as limiting the present invention.

The terms "first," "second," "third," and the like are used merely to distinguish between descriptions and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

As shown in fig. 1 and 2, the system for cooperatively treating the oily sludge by the coal-fired boiler comprises a biomass gasification system, an oily sludge pyrolysis system and a pyrolysis gas utilization system, which are sequentially connected.

Specifically, the biomass gasification system comprises a biomass conveying mechanism and a biomass gasification furnace 6; the oily sludge pyrolysis system comprises a low-nitrogen combustor 9, a hot blast stove 11, a pyrolysis rotary kiln 15, a slag cooler 16, an oily sludge storage bin 12 and an oily sludge conveying mechanism _； The pyrolysis gas utilization system includes a cyclone 17 and a coal-fired boiler 21.

Specifically, the biomass gasification furnace 6, the low-nitrogen burner 9, the hot blast stove 11, the pyrolysis rotary kiln 15, the cyclone dust collector 17, the burner 19 and the coal-fired boiler 21 are connected through pipelines in sequence; a biomass inlet is arranged on the biomass gasification furnace 6; the pyrolysis rotary kiln 15 is provided with a feed inlet and a slag discharge port, and the slag cooler 16 is connected with the slag discharge port of the pyrolysis rotary kiln 15; the slag cooler 16 and the low nitrogen burner 9 are connected by a pipeline.

Specifically, the slag discharging port of the pyrolysis rotary kiln 15 is arranged at one end close to the hot blast stove 11, and the feeding port is arranged at one end close to the cyclone dust collector 17.

Specifically, the end of the pyrolysis rotary kiln 15 near the hot blast stove 11 is inclined downward by 2 ° -3 °.

Specifically, the coal-fired boiler 21 is provided with a burner 19, and the cyclone dust collector 17 is connected with the burner 19 through a pipeline.

Specifically, a first gas fan 8 is arranged on a pipeline connected with the biomass gasifier 6 and the low-nitrogen burner 9; a second gas fan 18 is arranged on the pipeline between the cyclone dust collector 17 and the burner 19.

Specifically, the bottom of the biomass gasification furnace 6 is connected with a first blower 7; a second blower 10 is arranged on a pipeline of the slag cooler 16 connected with the low-nitrogen combustor 9; the burner 19 is connected to a third blower 20.

Specifically, the bottom of the biomass gasification furnace 6 is provided with an ash tray, the biomass inlet is formed in the top of the biomass gasification furnace 6, the first gas fan 8 is connected with the top of the biomass gasification furnace 6, and the first air blower 7 is connected with the bottom of the biomass gasification furnace 6.

Specifically, the biomass conveying mechanism comprises an upper bin 1, a first chain plate conveyor 2, a bucket elevator 3, a second chain plate conveyor 4, a buffer bin 5 and a pneumatic gate valve 22; the buffer storage bin 5 is arranged above the biomass gasifier and is communicated with a biomass inlet of the biomass gasifier, and the pneumatic gate valve 22 is arranged between the buffer storage bin 5 and the biomass gasifier 6; the first drag conveyer 2 is horizontally arranged, the feeding bin 1 is arranged above one end of the first drag conveyer 2, the bucket elevator 3 is vertically arranged at the other end of the first drag conveyer 2, the first drag conveyer 2 is positioned at the lower end of the bucket elevator 3, the second drag conveyer 4 is horizontally arranged at the upper end of the bucket elevator 3, and the second drag conveyer 4 is positioned above the buffer storage bin 5.

Specifically, the first scraper conveyor 2 can convey the biomass sent out by the feeding bin 1 to the bucket elevator 3, the bucket elevator 3 conveys the biomass from the first scraper conveyor 2 to the second scraper conveyor 4, the biomass is conveyed to the buffer bin 5 through the second scraper conveyor 4, and the biomass is sent to the biomass gasification furnace 6 through the pneumatic gate valve 22.

Specifically, the oily sludge conveying mechanism comprises a double-screw conveyor, a large-inclination-angle conveyor 13 and a screw conveyor 14, wherein the double-screw conveyor is arranged at the bottom of the oily sludge storage bin 12, one end of the large-inclination-angle conveyor 13 is connected with the double-screw conveyor at the bottom of the oily sludge storage bin 12, the other end of the large-inclination-angle conveyor is connected with the screw conveyor 14, and the screw conveyor 14 is arranged above the pyrolysis rotary kiln 15 and is connected with the feed inlet.

Specifically, a level gauge is provided in the biomass gasification furnace 6.

Specifically, the biomass gasifier 6 is an updraft fixed bed gasifier; the pyrolysis rotary kiln 15 is an internal heat rotary kiln.

The system for cooperatively treating the oily sludge by the coal-fired boiler comprises the following use flows:

the crushed biomass is sent to the feeding bin 1 through a forklift, the materials in the bin are sent to the bucket elevator 3 through the first chain plate conveyor 2, and the materials of the bucket elevator 3 are sent to the buffer storage bin 5 at the top of the biomass gasification furnace 6 through the second chain plate conveyor 4. When the biomass gasification furnace 6 is at a low grain level, the pneumatic gate valve 22 connected to the bottom of the buffer bin 5 is opened, materials enter the biomass gasification furnace 6, and when the biomass gasification furnace 6 is at a high grain level, the pneumatic gate valve 22 is closed to stop feeding. The biomass gasification furnace 6 takes air as a gasifying agent, is fed from an air inlet at the bottom of the biomass gasification furnace 6 through a first air blower 7, biomass is gasified into biomass fuel gas under anoxic combustion, the biomass is led out from the top of the biomass gasification furnace 6 through a first fuel gas air blower 8, and carbon residues are discharged from an ash tray at the bottom of the biomass gasification furnace 6.

The oily sludge is sent into an oily sludge storage bin 12, and the oily sludge is evenly sent into a large-inclination-angle conveyor 13 by a double-shaft screw conveyor at the bottom of the oily sludge storage bin, and is sent into the tail end of a pyrolysis rotary kiln 15 (namely one end of a cyclone dust collector 17) through the screw conveyor 14. The biomass fuel gas is mixed with high-temperature air sent by a second blower 10 by a fuel gas fan 8, and then fully combusted in a hot blast stove 11 after passing through a low-nitrogen burner 9, and high-temperature flue gas is generated and introduced into a pyrolysis rotary kiln 15. The high-temperature flue gas is at 500-600 ℃ and fully contacts with the oily sludge, the flowing direction of the high-temperature flue gas is opposite to the moving direction of the oily sludge, and the oil content and the water content in the oily sludge are heated to be above the gasification temperature, so that the separation of the oil content and the inorganic matters in the oily sludge is realized. The oily sludge moves from the tail end of the pyrolysis rotary kiln 15 to the front end of the pyrolysis rotary kiln 15 (i.e. the end close to the hot blast stove 11) and stays for 20-30min. The residual dregs after oil removal of the oily sludge are discharged from the front end dregs outlet of the pyrolysis rotary kiln 15, enter the dregs cooler 16, are cooled by air, and the heated high-temperature air is sent into the low-nitrogen burner 9 through the second blower 10.

The gas discharged from the pyrolysis rotary kiln 15 is sent into a cyclone dust collector 17, most of dust in the gas is removed, and then is sent into a combustor 19 on a coal-fired boiler 21 through a second gas fan 18, and is mixed with combustion air provided by a third air fan 20, and then is fully combusted in the coal-fired boiler 21, so that the purposes of harmless and recycling treatment of oil-containing sludge are achieved.

While the invention has been described with reference to one embodiment, it will be understood by those skilled in the art that various changes and substitutions of equivalents may be made without departing from the spirit and scope of the invention. Therefore, the protection scope of the invention is subject to the protection scope of the claims.

Claims (10)

1. The system for cooperatively treating the oily sludge by the coal-fired boiler is characterized by comprising a biomass gasifier, a low-nitrogen burner, a hot blast stove, a pyrolysis rotary kiln and the coal-fired boiler; the biomass gasification furnace, the low-nitrogen burner, the hot blast stove, the pyrolysis rotary kiln and the coal-fired boiler are sequentially connected through pipelines; the biomass gasification furnace is provided with a biomass inlet, and the pyrolysis rotary kiln is provided with a feed inlet and a slag discharge port.

2. The system for co-processing oil-containing sludge in coal-fired boiler according to claim 1, further comprising a slag cooler, wherein the slag cooler is connected with the slag discharging port, and the slag cooler is connected with the low-nitrogen burner through a pipeline.

3. The system for collaborative treatment of oil-containing sludge by a coal-fired boiler according to claim 2, further comprising a cyclone, wherein the cyclone is arranged on a pipeline between the pyrolysis rotary kiln and the coal-fired boiler.

4. The system for collaborative treatment of oil-containing sludge by a coal-fired boiler according to claim 3, wherein the slag discharging port of the pyrolysis rotary kiln is arranged at one end close to the hot blast stove, and the feeding port of the pyrolysis rotary kiln is arranged at one end close to the cyclone dust collector.

5. The system for cooperatively treating oil-containing sludge with a coal-fired boiler as claimed in claim 4, wherein the coal-fired boiler is provided with a burner, and the cyclone dust collector is connected with the burner through a pipeline.

6. The system for cooperatively treating oil-containing sludge by a coal-fired boiler according to claim 5, wherein a first gas fan is arranged on a pipeline connected with the biomass gasifier and the low-nitrogen burner; a second gas fan is arranged on the pipeline between the cyclone dust collector and the coal-fired boiler.

7. The system for co-processing oil-containing sludge in coal-fired boiler as claimed in claim 6, wherein said biomass gasification furnace is connected with a first blower; a second air blower is arranged on a pipeline connected with the low-nitrogen combustor of the slag cooler; the burner is connected with a third air blower.

8. The system for co-processing oil-containing sludge in coal-fired boiler as claimed in claim 7, wherein said biomass gasifier is an updraft fixed bed gasifier.

9. The system for collaborative treatment of oily sludge in a coal-fired boiler according to claim 8, wherein the pyrolysis rotary kiln is an internal heat rotary kiln.

10. A method for treating oil-containing sludge using the system for cooperatively treating oil-containing sludge of a coal-fired boiler according to any one of claims 1 to 9, comprising the steps of:

s1: gasifying biomass into biomass fuel gas in a biomass gasification furnace;

s2: mixing biomass fuel gas and preheated air provided by a second air blower in a low-nitrogen combustor, fully burning in a hot blast stove, and introducing the obtained high-temperature flue gas into a pyrolysis rotary kiln to fully contact with oily sludge, wherein oil and water in the oily sludge are gasified under the action of the high-temperature flue gas;

s3: and the gas discharged from the pyrolysis rotary kiln is sent into a coal-fired boiler for combustion after dust removal.