CN-121971998-A - High-efficiency internal circulation system and method for desulfurizing agent based on low-pressure conveying and precise grading

CN121971998ACN 121971998 ACN121971998 ACN 121971998ACN-121971998-A

Abstract

The invention discloses a high-efficiency internal circulation system and method for desulfurizing agents based on low-pressure conveying and precise grading, and relates to the technical field of industrial flue gas purification. The high-efficiency internal circulation system of the desulfurizing agent based on low-pressure conveying and precise grading realizes continuous conveying and two-stage grading integrated treatment of the desulfurizing ash, the ash conveying system stably conveys the desulfurizing ash to the two-stage precise sorting unit under preset pressure, the primary pre-separator carries out primary coarse separation on the desulfurizing ash to remove most of coarse particle desulfurization byproducts, the subsequent grading load is lightened, the secondary dynamic air classifier carries out precise grading on the fine powder-containing air flow, high-activity desulfurizing agent fine powder is precisely separated and sent into a desulfurizing agent bin, and coarse particles and medium-particle-size powder are sent into the desulfurizing ash bin.

Inventors

GAO HUAQING
Pang Qingzhou
FENG JINXING
XIE YOUPING
SHAO MINGJUN

Assignees

海汇环保设备股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260331

Claims (10)

1. High-efficient internal circulation system of desulfurizing agent based on low pressure is carried and precision classification, characterized by comprising: The ash conveying system is used for continuously conveying the desulfurization ash at a preset pressure; the feeding port of the two-stage precise sorting unit is connected with the outlet of the ash conveying system and is used for carrying out two-stage classification on conveyed desulfurized ash, and the two-stage precise sorting unit comprises a first-stage preseparator and a second-stage dynamic air flow classifier which are arranged in series; The desulfurizer bin is connected with the fine powder outlet of the secondary dynamic air classifier and is used for receiving and storing the separated high-activity desulfurizer fine powder; The desulfurization ash bin is connected with the coarse material outlet of the primary preseparator and the coarse material outlet of the secondary dynamic air classifier and is used for receiving and storing the separated coarse particle desulfurization ash.
2. The high-efficiency internal circulation system of the desulfurizing agent based on low-pressure conveying and precise grading according to claim 1, wherein the ash conveying system is a low-pressure continuous conveying system, the working pressure of the ash conveying system is 0.08-0.15 MPa, the system comprises a pneumatic conveying pump and a conveying pipeline connected with the pneumatic conveying pump, and the ash conveying system is used for stably conveying the desulfurized ash in a dense phase form.
3. The low-pressure conveying and precision grading-based efficient internal desulfurizing agent circulating system according to claim 1, wherein the secondary dynamic air flow grader comprises: the classifying shell is provided with the feed inlet, the fine powder outlet and the coarse material outlet; A classifying wheel rotatably installed inside the classifying housing; and the variable frequency motor is in driving connection with the classifying wheel and is used for changing the cutting particle size of the classifying wheel by adjusting the rotating speed, so that the powder with different particle sizes can be accurately separated.
4. The high-efficiency internal circulation system of desulfurizing agent based on low-pressure conveying and precise grading according to claim 1, wherein the system further comprises a pushing and sucking composite power system consisting of a front-stage pushing unit and a rear-stage sucking unit; the front-stage pushing unit comprises the ash conveying system and is used for pushing the desulfurized ash to the two-stage precise sorting unit; The rear-section suction unit comprises a dust remover fan connected with the desulfurizing agent bin and is used for forming negative pressure in the secondary dynamic air flow classifier and guiding the air flow containing fine powder to pass through.
5. The high-efficiency internal circulation system for desulfurizing agent based on low-pressure conveying and precise classification according to claim 1, wherein the rear-stage suction unit further comprises a local suction force generated by a classifying wheel rotating at high speed in the secondary dynamic air classifier, and the local suction force cooperates with a system negative pressure generated by a dust remover fan to suck fine powder meeting the particle size requirement into the classifying wheel and discharge the fine powder from the fine powder outlet.
6. The high-efficiency internal circulation system of desulfurizing agent based on low-pressure conveying and precise grading according to claim 1, wherein the primary pre-separator is a cyclone separator, and a feed inlet of the primary pre-separator is tangentially connected with an outlet of an ash conveying system and is used for realizing primary separation of coarse-particle desulfurization ash and dust-containing airflow under the action of centrifugal force.
7. The high-efficiency internal circulation system of desulfurizing agent based on low-pressure conveying and precise classification according to claim 1, wherein the feed inlet of the secondary dynamic air classifier is connected with the air outlet of the primary preseparator through an air guide pipeline, and the trend of the air guide pipeline is set to enable air flow to enter the classification area where the classification wheel is located from bottom to top.
8. The high-efficiency internal circulation system of desulfurizing agent based on low-pressure conveying and precise classification according to claim 1, wherein the coarse material outlet of the primary preseparator and/or the coarse material outlet of the secondary dynamic air classifier are/is connected to a mechanical conveying device through a pipeline, and the outlet of the mechanical conveying device is connected with the desulfurization ash bin.
9. The high-efficiency internal circulation system of the desulfurizing agent based on low-pressure conveying and precise grading according to claim 3, wherein the rotating speed adjusting range of the variable frequency motor is 800-1800r/min and is used for correspondingly sorting out high-activity calcium hydroxide fine powder with different particle size thresholds.
10. A method based on the low-pressure conveying and precision grading-based high-efficiency internal circulation system of desulfurizing agent as claimed in any one of claims 1 to 9, characterized in that it comprises the following steps: step S1, low-pressure conveying, namely continuously conveying desulfurization ash from a desulfurization reactor to a two-stage precise separation unit in a low-pressure and dense-phase mode through an ash conveying system with the working pressure lower than 0.2 MPa; S2, primary coarse separation, namely, the desulfurization ash enters a primary pre-separator, primary separation is carried out under the action of centrifugal force, the separated coarse desulfurization ash is discharged into a desulfurization ash bin, and the air flow containing unreacted desulfurizing agent fine powder enters the next stage; Step S3, secondary fine separation, namely, enabling dust-containing air flow to enter a secondary dynamic air flow classifier, generating a controllable centrifugal force field by adjusting the rotating speed of a classification wheel, enabling high-activity superfine desulfurizer powder with the air flow drag force larger than the centrifugal force to be sucked into the classification wheel, and discharging the powder from a fine powder outlet; And S4, recycling, namely conveying the high-activity desulfurizer fine powder discharged from the fine powder outlet into a desulfurizer bin for being sprayed into a desulfurization reactor again for use, and conveying the medium-grain-size powder discharged from the medium-coarse material outlet into a desulfurization ash bin.

Description

High-efficiency internal circulation system and method for desulfurizing agent based on low-pressure conveying and precise grading Technical Field The invention relates to the technical field of industrial flue gas purification, in particular to a high-efficiency internal circulation system and method for desulfurizing agents based on low-pressure conveying and precise grading. Background The calcium-based dry desulfurization technology is a common process for low-temperature flue gas in the industries of steel, electric power, building materials and the like, and is characterized in that high-activity calcium hydroxide powder is sprayed into a flue to react with sulfur dioxide to generate desulfurization ash mainly comprising calcium sulfite, calcium sulfate and unreacted calcium hydroxide, and in order to improve the utilization rate of a desulfurizing agent, the recycling of the unreacted calcium hydroxide in the desulfurization ash is already an industry consensus. In the prior art, a traditional bin pump type pneumatic conveying system generally adopts a high-pressure (more than 0.4 MPa) intermittent conveying mode to push all the desulfurized ash to an ash bin, and a centrifugal or vortex type separator is arranged for subsequent separation, so that the scheme can realize centralized treatment of the desulfurized ash, but the high-pressure conveying energy consumption is higher, the abrasion of a pipeline and a valve is serious, a conveying and separating system is relatively independent, the flow is long, the occupied area is large, a simple cyclone separator is adopted for carrying out online separation, although a part of conveying links are omitted, the classification precision of the cyclone separator is limited, unreacted calcium hydroxide and desulfurization byproducts with similar particle sizes are difficult to effectively distinguish, the impurity content in the reclaimed materials is high, the activity is low, the reclaimed materials cannot be directly recycled to a desulfurization system, meanwhile, fine powder in the system is easy to concentrate, the subsequent equipment is blocked, and the long-term stable operation of the system is influenced. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a high-efficiency internal circulation system and method for desulfurizing agents based on low-pressure conveying and precise grading, which realize continuous conveying and two-stage grading integrated treatment of desulfurized ash by adopting a structural design of a combination of an ash conveying system and a two-stage precise sorting unit formed by connecting a first-stage preseparator and a second-stage dynamic air classifier in series, wherein the ash conveying system stably conveys the desulfurized ash to the two-stage precise sorting unit under preset pressure, the first-stage preseparator carries out primary coarse separation on the desulfurized ash to remove most of coarse particle desulfurization byproducts, the subsequent classification load is reduced, the second-stage dynamic air classifier carries out precise grading on the air flow containing fine powder, precisely separates high-activity desulfurizing agent fine powder and sends the high-activity desulfurizing agent fine powder into a desulfurizing agent bin, and coarse particles and medium-particle-size powder are sent into a desulfurizing ash bin. In order to achieve the purpose, the invention is realized by the following technical scheme that the high-efficiency internal circulation system of the desulfurizing agent based on low-pressure conveying and precise grading comprises: The ash conveying system is used for continuously conveying the desulfurization ash at a preset pressure; the feeding port of the two-stage precise sorting unit is connected with the outlet of the ash conveying system and is used for carrying out two-stage classification on conveyed desulfurized ash, and the two-stage precise sorting unit comprises a first-stage preseparator and a second-stage dynamic air flow classifier which are arranged in series; The desulfurizer bin is connected with the fine powder outlet of the secondary dynamic air classifier and is used for receiving and storing the separated high-activity desulfurizer fine powder; The desulfurization ash bin is connected with the coarse material outlet of the primary preseparator and the coarse material outlet of the secondary dynamic air classifier and is used for receiving and storing the separated coarse particle desulfurization ash. Preferably, the ash conveying system is a low-pressure continuous conveying system, the working pressure of the ash conveying system is 0.08MPa to 0.15MPa, the ash conveying system comprises a pneumatic conveying pump and a conveying pipeline connected with the pneumatic conveying pump, and the ash conveying system is used for stably conveying the desulfurization ash in a dense-phase form. Preferably, the secondary dynamic a