CN111256153B

CN111256153B - Sludge pre-drying and direct combustion system for circulating fluidized bed boilers

Info

Publication number: CN111256153B
Application number: CN202010198104.3A
Authority: CN
Inventors: 王绍民; 张庆; 张伟强; 刘冠杰; 郭涛; 吕海生; 李强
Original assignee: Huaneng Clean Energy Research Institute
Current assignee: Huaneng Clean Energy Research Institute
Priority date: 2020-03-19
Filing date: 2020-03-19
Publication date: 2025-01-28
Anticipated expiration: 2040-03-19
Also published as: CN111256153A

Abstract

The invention discloses a sludge pre-drying and direct-furnace mixing and burning system suitable for a circulating fluidized bed boiler, comprising a wet sludge bin, pre-drying equipment, a dry sludge storage bin, a coal conveying belt, a sludge distribution belt, a sludge bin in front of a furnace, a rotary plugging removal device, a furnace feed spiral, a material drop pipe and a circulating fluidized bed boiler; the outlet of the wet sludge bin is connected to the inlet of the circulating fluidized bed boiler via the pre-drying equipment, the dry sludge storage bin, the coal conveying belt, the sludge distribution belt, the sludge bin in front of a furnace, the rotary plugging removal device, the furnace feed spiral and the material drop pipe in sequence, and the system can achieve the purpose of simultaneously treating wet sludge with a moisture content of 70% to 85% and wet sludge with a moisture content of 50% to 65%, and the treatment cost is low.

Description

Sludge predrying direct-access furnace blending combustion system suitable for circulating fluidized bed boiler

Technical Field

The invention belongs to the technical field of environmental protection, and relates to a sludge predrying direct-access furnace blending combustion system suitable for a circulating fluidized bed boiler.

Background

In recent years, the problem of 'sludge surrounding city' is more serious, and the development of sludge treatment technology is unprecedented. Compared with the traditional sanitary landfill, agricultural utilization, ocean disposal, building material utilization and the like, the sludge incineration is the most thorough sludge treatment mode, and has the outstanding advantages of high treatment speed, high reduction degree, resource reuse and the like.

For sewage treatment plants, the sludge incineration technology is adopted to construct an incinerator and a tail gas purification treatment system, so that the project investment is large, the operation cost is high and the economical efficiency is poor. The coal-fired boiler is a natural sludge incinerator, and particularly has the advantages of wide fuel adaptability, high combustion efficiency, low pollutant emission and the like.

According to the sludge blending burning mode, sludge burning can be divided into two kinds of wet sludge direct-feeding furnace blending burning and wet sludge drying and then burning. The sludge drying and incinerating technology is to dry wet sludge with the water content of about 80% by a newly built sludge drying system to the water content of below 40% and then to incinerate the wet sludge in a furnace. The traditional wet sludge direct-feeding furnace blending technology is characterized in that the wet sludge with the water content lower than 65% is mixed with coal by using a coal conveying system of a power plant and then is fed into a boiler, and the wet sludge with the water content higher than 70% is in a thick slurry state and can only be pumped into the boiler by using a special sludge screw pump.

The conventional wet sludge direct-feeding furnace co-firing system can only treat sludge with a water content in a range (such as 50% -65% or 70% -85%) of water content. In the current engineering application field, a direct-access furnace blending technology is generally adopted for wet sludge with the water content of 50% -65%. For wet sludge with the water content of 70% -85%, the wet sludge is generally dried to the water content below 40% by a sludge drying system and then is put into a furnace for incineration, and at the moment, a new sludge drying system is needed, the equipment investment of the drying system is large, the heat source energy consumption is large and the operation cost is high.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, and provides a sludge predrying direct-access furnace co-firing system suitable for a circulating fluidized bed boiler, which can realize the purpose of simultaneously treating wet sludge with the water content of 70% -85% and wet sludge with the water content of 50% -65%, and has lower treatment cost.

In order to achieve the aim, the sludge predrying direct-access furnace doping combustion system suitable for the circulating fluidized bed boiler comprises a wet sludge bin, predrying equipment, a dry sludge storage bin, a coal conveying belt, a sludge distribution belt, a stokehole sludge bin, a rotary blocking removing device, a furnace feeding screw, a blanking pipe and the circulating fluidized bed boiler;

The outlet of the wet sludge bin is communicated with the inlet of the circulating fluidized bed boiler through predrying equipment, a dry sludge storage bin, a coal conveying belt, a sludge distribution belt, a stokehold sludge bin, a rotary blocking removing device, a furnace feeding screw and a blanking pipe in sequence.

The device also comprises a sludge pre-drying workshop, wherein the wet sludge bin, the pre-drying equipment and the dry sludge storage bin are all positioned in the sludge pre-drying workshop.

And an air outlet of the sludge predrying workshop is communicated with a circulating fluidized bed boiler through a negative pressure fan and a booster fan.

The wet sludge bin is communicated with the pre-drying equipment through wet sludge conveying equipment.

The pre-drying equipment is communicated with the dry sludge storage bin through a dry sludge discharging and conveying device.

The dry sludge storage bin is connected with the coal conveying belt through dry sludge conveying equipment.

The pre-drying equipment dries the wet sludge from 70% -85% to 50% -65%, and a plate-and-frame filter press, a high-pressure belt filter press or other mechanical drying machines can be adopted.

The invention has the following beneficial effects:

when the sludge predrying direct-access furnace blending combustion system suitable for the circulating fluidized bed boiler is specifically operated, wet sludge with the water content of 70% -85% sent by a sewage treatment plant is dried to the water content of 50% -65% through predrying equipment, then the wet sludge and the sludge with the water content of 50% -65% directly sent by the sewage treatment plant are sent into a dry sludge storage bin, and then sludge incineration treatment is carried out through a dried sludge storage bin system and a sludge incineration system, so that the aim of simultaneously treating the wet sludge with the water content of 70% -85% and the wet sludge with the water content of 50% -65% is fulfilled, the system is simple, the operation reliability is high, and the treatment cost is low.

Further, the wet sludge bin, the pre-drying equipment and the dry sludge bin are all positioned in the sludge pre-drying workshop, and an air outlet of the sludge pre-drying workshop is communicated with the circulating fluidized bed boiler through a negative pressure fan and a booster fan, so that odor generated in the treatment process is directly sent into the circulating fluidized bed boiler for combustion, and odorless emission of the whole sludge treatment process of the power plant is realized.

Drawings

Fig. 1 is a schematic structural view of the present invention.

Wherein, 1 is wet sludge bin, 2 is wet sludge conveying equipment, 3 is predrying equipment, 4 is dry sludge discharging and conveying device, 5 is dry sludge storage bin, 6 is dry sludge conveying equipment, 7 is coal conveying belt, 8 is sludge distributing belt, 9 is stokehold sludge bin, 10 is rotary block-removing device, 11 is furnace feeding screw, 12 is blanking pipe, 13 is circulating fluidized bed boiler, 14 is negative pressure fan, 15 is booster fan, 16 is sludge predrying workshop.

Detailed Description

The invention is described in further detail below with reference to the attached drawing figures:

Referring to fig. 1, the sludge predrying direct-access furnace blending combustion system suitable for the circulating fluidized bed boiler comprises a wet sludge warehouse 1, predrying equipment 3, a dry sludge warehouse 5, a coal conveying belt 7, a sludge distribution belt 8, a stokehold sludge warehouse 9, a rotary blocking removing device 10, a furnace feeding screw 11, a blanking pipe 12 and the circulating fluidized bed boiler 13, wherein an outlet of the wet sludge warehouse 1 is communicated with an inlet of the circulating fluidized bed boiler 13 through the predrying equipment 3, the dry sludge warehouse 5, the coal conveying belt 7, the sludge distribution belt 8, the stokehold sludge warehouse 9, the rotary blocking removing device 10, the furnace feeding screw 11 and the blanking pipe 12 in sequence.

The invention also comprises a sludge predrying workshop 16, wherein the wet sludge bin 1, the predrying equipment 3 and the dry sludge storage bin 5 are all positioned in the sludge predrying workshop 16.

Specifically, an air outlet of a sludge predrying workshop 16 is communicated with a circulating fluidized bed boiler 13 through a negative pressure fan 14 and a booster fan 15, a wet sludge bin 1 is communicated with predrying equipment 3 through wet sludge conveying equipment 2, predrying equipment 3 is communicated with a dry sludge storage bin 5 through a dry sludge discharging and conveying device 4, and the dry sludge storage bin 5 is connected with a coal conveying belt 7 through dry sludge conveying equipment 6.

The wet sludge pre-drying process comprises the steps that wet sludge with the water content of 70% -85% temporarily stored in a wet sludge bin 1 is conveyed into a pre-drying device 3 through a wet sludge conveying device 2, and the sludge is dried to the water content of 50% -65% through the pre-drying device 3 and then conveyed into a dry sludge storage bin 5 through a dry sludge discharging and conveying device 4.

The dry sludge adding process is that dry sludge with the water content of 50% -65% temporarily stored in a dry sludge storage bin 5 is conveyed to a coal conveying belt 7 through a dry sludge conveying device 6, conveyed to the front of a furnace by the aid of the existing coal conveying belt 7, and conveyed to a sludge storage bin 9 in front of the furnace through a sludge distribution belt 8.

The sludge incineration system flow is that sludge in a stokehold sludge bin 9 enters a furnace feeding screw 11 through a rotary blocking removing device 10 and then enters a circulating fluidized bed boiler 13 through a blanking pipe 12 for incineration.

The odor treatment process comprises the steps of sucking odor in a wet sludge bin 1, wet sludge conveying equipment 2, pre-drying equipment 3, a dry sludge discharging and conveying device 4, a dry sludge storage bin 5, dry sludge conveying equipment 6, a sludge pre-drying workshop 16 and the like by adopting a negative pressure fan 14, and conveying the odor to a circulating fluidized bed boiler 13 for burning by a booster fan 15 through an odor conveying pipeline.

Two types of sludge sources with the water content of 50% -65% are used in the dry sludge storage bin 5, one type of sludge is produced by drying wet sludge with the water content of 70% -85% through the pre-drying equipment 3, and the other type of sludge with the water content of 50% -65% are directly sent by a tank car of a sewage treatment plant.

The method comprises the working principle that wet sludge with the water content of 70% -85% sent by a sewage treatment plant is dried to the water content of 50% -65% through a pre-drying device 3, then the wet sludge and the sludge with the water content of 50% -65% directly sent by the sewage treatment plant are sent into a dry sludge storage bin 5, then sludge incineration treatment is carried out through a dried sludge storage bin adding system and a sludge incineration system, and odor generated in the sludge treatment process is sent to a boiler for incineration through an odor treatment system.

Although embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives, and variations may be made in the above embodiments by those skilled in the art without departing from the spirit and principles of the invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A sludge pre-drying and direct-into-furnace co-combustion system suitable for a circulating fluidized bed boiler, characterized in that it comprises a wet sludge bin (1), a pre-drying device (3), a dry sludge storage bin (5), a coal conveyor belt (7), a sludge distribution belt (8), a sludge bin in front of the furnace (9), a rotary clearing device (10), a furnace feeding spiral (11), a material dropping pipe (12) and a circulating fluidized bed boiler (13);

The outlet of the wet sludge bin (1) is connected to the inlet of the circulating fluidized bed boiler (13) via the pre-drying device (3), the dry sludge storage bin (5), the coal conveyor belt (7), the sludge distribution belt (8), the sludge bin in front of the furnace (9), the rotary blockage clearing device (10), the furnace inlet spiral (11) and the drop pipe (12) in sequence;

It also includes a sludge pre-drying workshop building (16), wherein the wet sludge bin (1), the pre-drying equipment (3) and the dry sludge storage bin (5) are all located in the sludge pre-drying workshop building (16);

The air outlet of the sludge pre-drying workshop (16) is connected to the circulating fluidized bed boiler (13) via a negative pressure fan (14) and a booster fan (15);

The wet sludge bin (1) is connected to the pre-drying device (3) via the wet sludge conveying device (2);

The wet sludge temporarily stored in the wet sludge bin (1) with a moisture content of 70% to 85% is transported to the pre-drying device (3) through the wet sludge conveying device (2), and then the sludge is dried to a moisture content of 50% to 65% by the pre-drying device (3), and then transported to the dry sludge storage bin (5) by the dry sludge discharging conveying device (4);

The drying sludge storage process is as follows: the dry sludge with a moisture content of 50% to 65% temporarily stored in the dry sludge storage bin (5) is transported to the coal conveyor belt (7) through the dry sludge conveying equipment (6), and then transported to the front of the furnace by using the existing coal conveyor belt (7), and then transported to the sludge bin (9) in front of the furnace by the sludge distribution belt (8);

The sludge with a moisture content of 50% to 65% in the dry sludge storage bin (5) has two sources: one is the sludge produced by drying wet sludge with a moisture content of 70% to 85% through the pre-drying device (3); the other is the sludge with a moisture content of 50% to 65% directly delivered by tank trucks from the sewage treatment plant.

2. The sludge pre-drying and direct-to-furnace co-combustion system suitable for a circulating fluidized bed boiler according to claim 1 is characterized in that the pre-drying equipment (3) is connected to the dry sludge storage bin (5) via a dry sludge discharge conveying device (4).

3. The sludge pre-drying and direct combustion system for circulating fluidized bed boilers according to claim 1 is characterized in that the dry sludge storage bin (5) is connected to the coal conveyor belt (7) via the dry sludge conveying equipment (6).