WO2022094917A1

WO2022094917A1 - Lime slurry preparation system for waste incineration plant

Info

Publication number: WO2022094917A1
Application number: PCT/CN2020/127060
Authority: WO
Inventors: 张雷; 王勇涛; 郑伟
Original assignee: 桂林市深能环保有限公司; 潮州深能环保有限公司; 深圳市能源环保有限公司; 深圳市深能环保东部有限公司; 深圳市深能环保城市环境服务有限公司; 武汉深能环保新沟垃圾发电有限公司; 单县深能环保有限公司
Priority date: 2020-11-06
Filing date: 2020-11-06
Publication date: 2022-05-12

Abstract

A lime slurry preparation system for a waste incineration plant, the system comprising: a digestion device (1), a dilution device (2) and a lime slurry conveying device (3); and further comprising: a Venturi dust removal device (4), wherein a first lime slurry backflow pipeline (4.2) is further provided, one end of the first lime slurry backflow pipeline (4.2) being connected to a slurry output pipeline (3.2B), and the other end thereof being connected to a first inlet (4.1A1) of a Venturi negative-pressure suction washing device (4.1). A steam collection pipeline (4.3) is further arranged at the top of a digestion tank (1.4), one end of the steam collection pipeline (4.3) being connected to the digestion tank (1.4), and the other end thereof being connected to a second inlet (4.1A2) of the Venturi negative-pressure suction washing device (4.1); and an outlet (4.1B) of the Venturi negative-pressure suction washing device (4.1) is connected to a dilution tank (2.1). By means of adding a lime slurry backflow pipeline, a small portion of an output slurry of the slurry output pipeline (3.2B) in the lime slurry conveying device (3) is conveyed to an atomizer, and the majority of the output slurry flows into the Venturi negative-pressure suction washing device (4.1) via the first inlet (4.1A1), such that in a Venturi pipe, moist hot steam and a backflow slurry are mixed and condensed, and finally flow back to the dilution tank (2.1), thereby eliminating the moist hot steam.

Description

A system for preparing lime slurry in waste incineration plant

technical field

The invention relates to a lime slurry preparation system of a waste incineration plant.

Background technique

With the rapid development of waste incineration power generation, its flue gas treatment system has become more mature and standardized in design and management. In terms of flue gas deacidification process, semi-dry deacidification system is generally adopted as the main deacidification process. According to To meet local emission standards, supplement the dry deacidification or wet deacidification system as an auxiliary deacidification process. At present, the mainstream semi-dry deacidification system uses a high-speed rotary atomizer to spray lime slurry. In order to ensure the high efficiency of the neutralization reaction and take into account the processing cost, it is necessary to cooperate with the construction of a lime slurry preparation system and use quicklime to prepare lime slurry on site.

The lime slurry preparation system is mainly composed of lime storage silo, digestion tank, dilution tank, lime slurry delivery pump, slurry delivery pipeline, etc. According to the lime slurry preparation and dosing process, when the dilution tank sends a low level signal, the lime in the lime silo will be transported to the digestion tank through the ash discharge valve and screw conveyor, and a certain proportion of tap water will enter the digestion tank to digest the lime. Treatment, as the liquid level of the digestion tank rises, the lime slurry after digestion overflows to the dilution tank through the overflow pipe of the digestion tank, and the tap water inlet valve of the dilution tank is opened to dilute the lime slurry to an appropriate preset concentration. When the high level is reached, the lime slurry preparation stops. The lime slurry in the dilution tank is transported to the atomizer through the lime slurry pump and the lime slurry circulation pipeline for deacidification of the flue gas, and the remaining lime slurry is returned to the dilution tank. The flow rate of the lime slurry pump is much larger than the actual demand of the lime slurry in the atomizer. Usually, the delivery volume of the lime slurry pump is 5-7 times the actual demand of the atomizer, so as to improve the flow rate of the pipeline and avoid the blockage of the pipeline and the remaining lime slurry. Return to the dilution tank. Since the digestion process is an exothermic process, a certain amount of hot and humid steam with lime powder will be generated in the digestion tank. At present, this part of the steam is mostly treated by centrifugal fans and then concentrated spray washing. However, because the steam carries lime powder, it is easy to cause scaling and blockage of the spray washing system including the fan, and it is difficult to run smoothly for a long time. Maintenance workload is high.

SUMMARY OF THE INVENTION

In order to overcome the problems of unstable operation and large maintenance workload of the hot steam washing system of the digestion tank when preparing lime slurry in a waste incineration plant, the present invention proposes a lime slurry preparation system for a waste incineration plant, including a digestion device, a dilution device, and a lime slurry conveying device. It also includes a venturi dust removal device, and a first lime slurry return pipeline is also provided, one end of the lime slurry return pipeline is connected with the pump outlet pipeline and the other end is connected with the first inlet of the venturi negative pressure suction and washing device. . The top of the digestion tank is also provided with a steam collection pipe, one end of the steam collection pipe is connected with the digestion tank and the other end is connected with the second inlet of the venturi negative pressure suction washing device; the venturi negative pressure suction The outlet of the suction washing device is connected to the dilution tank. By adding a lime slurry return pipe, a small part of the output slurry of the lime slurry conveying device is transported to the atomizer and most of it flows into the venturi negative pressure suction washing device through the first inlet. In the venturi pipe, The wet and hot steam is mixed and condensed with the reflux slurry, and finally returned to the dilution tank to effectively eliminate the wet and hot steam.

The technical scheme adopted by the present invention to solve the technical problem is as follows: a lime slurry preparation system for a waste incineration plant, including a digestion device, a dilution device, and a lime slurry conveying device. The solution prepared by the digestion device flows into the dilution device, and then passes through the dilution device. The lime slurry conveying device is conveyed to the atomizer;

Described digestion device, according to the direction that lime slurry flows, comprises lime silo, ash discharge valve, screw conveyor and digestion tank successively, also comprises the first tap water branch pipe that flows into described digestion tank;

The dilution device includes a dilution tank and an overflow pipe flowing into the dilution tank from the digestion tank, and also includes a second tap water branch pipe connected to the dilution tank;

The lime slurry conveying device includes a conveying pump, a pump inlet pipe that flows into the conveying pump from the dilution tank, and a slurry output pipe that is conveyed to the atomizer by the conveying pump;

It is characterized in that it also includes a venturi dust removal device, the venturi dust removal device includes a venturi negative pressure suction and washing device, and a first lime slurry return pipe is also provided, and one end of the first lime slurry return pipe is connected to the slurry output. The pipeline is connected and the other end is connected with the first inlet of the venturi negative pressure suction washing device;

The top of the digestion tank is also provided with a steam collection pipe, one end of the steam collection pipe is connected with the digestion tank and the other end is connected with the second inlet of the venturi negative pressure suction washing device; the venturi negative pressure suction The outlet of the suction washing device is connected to the dilution tank.

A preferred solution is that a second lime slurry return pipeline is also provided, one end of the second lime slurry return pipeline is connected to the first lime slurry return pipeline and the other end is directly connected to the dilution tank.

Preferably, a venturi flushing pipe is also provided, one end of the venturi flushing pipe is connected to the second tap water branch pipe, and the other end is connected to the venturi negative pressure suction and washing device through a tee together with the first return pipe The first inlet of the pipeline is provided with a valve, and the Venturi negative pressure suction and washing device is flushed by switching the valve.

A preferred solution is that the steam collection pipe adopts a corrugated hose and the two ends are connected by quick-connect flanges.

Beneficial effects of the present invention: The present invention proposes a lime slurry preparation system for a waste incineration plant. Since a Venturi dust removal device is provided, the Venturi dust removal device includes a Venturi negative pressure suction and washing device. By adding a lime slurry return pipe, A part of the slurry in the slurry output pipeline of the lime slurry conveying device flows through the venturi negative pressure suction and washing device. In the venturi tube, the hot and humid steam and the reflux slurry are mixed and condensed, and finally returned to the dilution tank, which effectively removes the hot and humid steam. to eliminate.

Description of drawings

FIG. 1 is a schematic diagram of a device arrangement according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a device arrangement according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram of a device arrangement according to a third embodiment of the present invention.

FIG. 4 is a schematic diagram of a device arrangement according to a fourth embodiment of the present invention.

In the picture:

1 digestion unit, 1.1 lime silo, 1.2 ash discharge valve, 1.3 screw conveyor, 1.4 digestion tank, 1.5 first tap water branch pipe;

2 dilution device, 2.1 dilution tank, 2.2 overflow pipe, 2.3 second tap water branch pipe, 2.3A venturi flushing pipe;

3 lime slurry conveying device, 3.1 conveying pump, 3.2A inlet pump pipeline, 3.2B slurry output pipeline;

4. Venturi dust removal device, 4.1 Venturi negative pressure suction and washing device, 4.1A1 Venturi first inlet, 4.1A2 Venturi second inlet, 4.1B Venturi first outlet, 4.2 First lime slurry return pipeline, 4.2A first Two lime slurry return pipeline, 4.21 tee, 4.3 steam collection pipeline.

Detailed ways

FIG. 1 is a schematic diagram of a device arrangement according to a first embodiment of the present invention. The figure shows that, in this example, a lime slurry preparation system for a waste incineration plant includes a digestion device 1, a dilution device 2, and a lime slurry conveying device 3; the solution prepared by the digestion device 1 flows into the dilution device 2, and then passes through the lime slurry conveying device. 3 to the nebulizer.

The digestion device 1, according to the flow direction of the lime slurry, sequentially includes a lime silo 1.1, an ash discharge valve 1.2, a screw conveyor 1.3 and a digestion tank 1.4, and also includes a first tap water branch pipe 1.5 flowing into the digestion tank;

The dilution device 2 includes a dilution tank 2.1, an overflow pipe 2.2 flowing into the dilution tank 2.1 from the digestion tank 1.4, and a second tap water branch pipe 2.3 connected to the dilution tank 2.1;

The lime slurry conveying device 3 includes a conveying pump 3.1, which flows into the pump inlet pipe 3.2A of the conveying pump 3.1 from the dilution tank 2.1, and is conveyed by the conveying pump 3.1 to the slurry output pipe 3.2B of the atomizer;

As shown in the figure, in this example, a venturi dust removal device 4 is also included. The venturi dust removal device includes a venturi negative pressure suction and washing device 4.1, and a first lime slurry return pipe 4.2 is also provided. The first lime slurry returns One end of the pipeline 4.2 is connected with the slurry output pipeline 3.2B and the other end is connected with the first inlet 4.1A1 of the Venturi negative pressure suction washing device 4.1;

The top of the digestion tank 1.4 is also provided with a steam collection pipe 4.3, one end of the steam collection pipe 4.3 is connected with the digestion tank 1.5 and the other end is connected with the second inlet 4.1A2 of the Venturi negative pressure suction and washing device 4.1; The outlet 4.1B of the venturi negative pressure suction washing device 4.1 is connected to the dilution tank 2.1.

The figure shows that in this example, by adding the first lime slurry return pipe 4.2, a part of the slurry in the slurry output pipe 3.2B in the lime slurry conveying device is used to flow through the Venturi negative pressure suction and washing device. In the process, the moist heat steam and the reflux slurry are mixed and condensed, and finally returned to the dilution tank to effectively eliminate the moist heat steam.

FIG. 2 is a schematic diagram of a device arrangement according to a second embodiment of the present invention. The figure shows that, different from the first embodiment, in this example, a second lime slurry return pipeline 4.2A is also provided, and one end of the second lime slurry return pipeline 4.2A is connected to the first lime slurry return pipeline 4.2 Connect the other end directly into the dilution tank 2.1.

FIG. 3 is a schematic diagram of a device arrangement according to a third embodiment of the present invention. The figure shows that, different from the first embodiment, in this example, a venturi flushing pipe 2.3A is also provided, one end of the venturi flushing pipe 2.3A is connected to the second tap water branch pipe 2.3 and the other end is connected to the second tap water branch pipe 2.3 through a tee 4.21. The first return pipeline 4.2 is connected to the first inlet 4.1A1 of the Venturi negative pressure suction and washing device 4.1, a valve is set on the pipeline, and the Venturi negative pressure suction and washing device 4.1 is switched through the valve. Rinse.

FIG. 4 is a schematic diagram of a device arrangement according to a fourth embodiment of the present invention. The figure shows that, different from the first embodiment, in this embodiment, the steam collecting pipe 4.3 adopts a corrugated hose and the two ends are connected by quick-connect flanges.

Claims

A lime slurry preparation system for a waste incineration plant, comprising a digestion device, a dilution device, and a lime slurry conveying device, the solution prepared by the digestion device flows into the dilution device, and then is conveyed to an atomizer through the lime slurry conveying device;

The digestion device, according to the flow direction of the lime slurry, sequentially includes a lime silo, an ash discharge valve, a screw conveyor and a digestion tank, and also includes a first tap water branch pipe flowing into the digestion tank;

The dilution device includes a dilution tank and an overflow pipe flowing into the dilution tank from the digestion tank, and also includes a second tap water branch pipe connected to the dilution tank;

The lime slurry conveying device includes a conveying pump, a pump inlet pipe that flows into the conveying pump from the dilution tank, and a slurry output pipe that is conveyed to the atomizer by the conveying pump;

It is characterized in that it also includes a venturi dust removal device, the venturi dust removal device includes a venturi negative pressure suction and washing device, and a first lime slurry return pipe is also provided, and one end of the first lime slurry return pipe is connected to the slurry output. The pipeline is connected and the other end is connected with the first inlet of the venturi negative pressure suction washing device;

The top of the digestion tank is also provided with a steam collection pipe, one end of the steam collection pipe is connected with the digestion tank and the other end is connected with the second inlet of the venturi negative pressure suction washing device; the venturi negative pressure suction The outlet of the suction washing device is connected to the dilution tank.
A system for preparing lime slurry for a waste incineration plant according to claim 1, characterized in that a second lime slurry return pipeline is further provided, and one end of the second lime slurry return pipeline is connected to the first lime slurry return pipeline. The other end is directly connected to the dilution tank.
A system for preparing lime slurry for a waste incineration plant according to claim 1, characterized in that a venturi flushing pipeline is also provided, one end of the venturi flushing pipeline is connected to the second tap water branch pipeline, and the other end is connected to the first tap water through a tee. A return pipeline is connected to the first inlet of the venturi negative pressure suction and washing device together, a valve is set on the pipeline, and the venturi negative pressure suction and washing device is washed by switching the valve.
A system for preparing lime slurry in a waste incineration plant according to claim 1, wherein the steam collecting pipe adopts a corrugated hose and the two ends are connected by a quick-connect flange.