CN-121990739-A - Multistage sludge drying system and drying method

CN121990739ACN 121990739 ACN121990739 ACN 121990739ACN-121990739-A

Abstract

The invention discloses a multistage sludge drying system which comprises a feeding unit, a multistage serial drying unit, a heat exchange circulation unit, a moisture removal unit and a discharging unit, wherein the multistage serial drying unit comprises a low-temperature preheating module, a medium-temperature evaporation module and a high-temperature setting module which are sequentially arranged, the heat exchange circulation unit is respectively communicated with each module in the multistage serial drying unit and provides heat mediums with different temperature ranges for each module, the moisture removal unit is respectively communicated with each module in the multistage serial drying unit and is used for collecting and discharging moisture in each module, and the multistage serial drying system further comprises a control unit which is respectively connected with the feeding unit, the multistage serial drying unit, the heat exchange circulation unit, the moisture removal unit and the discharging unit through signals and is used for controlling the sludge conveying speed, the heat medium parameters and the moisture removal amount based on the acquired working conditions of each unit. Compared with the prior art, the multistage sludge drying system and the drying method have the advantages that the multistage sludge drying system and the drying method for carrying out sectional gradient heating according to the sludge drying characteristics are provided.

Inventors

DENG JIAJIA
LIU JIAHE
Xue tianli
HUANG SHIFANG
TU FANGXIANG
NING XUE
WEI CHONGGAO
XU SHENGYONG
PAN GAOGANG
WEI LIXUAN

Assignees

广西电力职业技术学院
桂润环境科技股份有限公司
广西森工矿业投资有限公司

Dates

Publication Date: 20260508
Application Date: 20260305

Claims (9)

1. The multistage sludge drying system is characterized by comprising a feeding unit, a multistage serial drying unit, a heat exchange circulation unit, a dehumidifying unit and a discharging unit; The multi-stage serial drying unit comprises a low-temperature preheating module, a medium-temperature evaporating module and a high-temperature setting module which are sequentially arranged, and the heat exchange circulation unit is respectively communicated with each module in the multi-stage serial drying unit and provides heat mediums with different temperature ranges for each module; the moisture removing unit is respectively communicated with each module in the multistage serial drying unit, and collects and discharges moisture in each module; the system also comprises a control unit which is respectively connected with the feeding unit, the multistage serial drying unit, the heat exchange circulation unit, the dehumidifying unit and the discharging unit in a signal way, and the sludge conveying speed, the heat medium parameters and the dehumidifying amount are controlled based on the obtained working conditions of the units.
2. The multistage sludge drying system according to claim 1, wherein the low-temperature preheating module, the medium-temperature evaporating module and the high-temperature shaping module are respectively provided with an independent stirring and conveying mechanism, and each stirring and conveying mechanism comprises a driving motor, a transmission shaft and special-shaped stirring blades distributed along the axial direction; the pitch or the inclination angle of the special-shaped stirring blade is gradually changed along the flowing direction of the sludge.
3. The multistage sludge drying system according to claim 2, wherein the feeding unit comprises a sludge receiving hopper, a crushing and refining device and a quantitative feeder which are sequentially arranged; The crushing and homogenizing device is used for shearing, crushing, mixing and homogenizing the sludge, and the constant feeder is used for conveying the homogenized sludge to the low-temperature preheating module according to a set flow.
4. The multistage sludge drying system of claim 1, wherein the heat exchange circulation unit comprises at least two independent heat medium generating devices and a heat medium mixing adjuster; The two heat medium generating devices respectively generate a low-temperature interval heat medium and a high-temperature interval heat medium, and the heat medium mixing and adjusting device mixes the heat mediums with different temperatures in proportion according to the instruction of the control unit to generate a medium-temperature interval heat medium.
5. The multistage sludge drying system of claim 4, wherein the heat exchange circulation unit further comprises a circulation pump set, and the circulation pump set controls the flow of the heat medium to each module and circulates in a loop.
6. The multi-stage sludge drying system as claimed in claim 1, wherein the dehumidifying unit comprises a dehumidifying port, a collecting pipe and a heat recovery mechanism, wherein the dehumidifying port is respectively communicated with the low-temperature preheating module, the medium-temperature evaporating module and the high-temperature shaping module, and the collecting pipe is connected with the multi-stage dehumidifying port; the heat recovery mechanism collects the hot and humid gas exhausted by each module and extracts sensible heat and latent heat from the hot and humid gas.
7. The multi-stage sludge drying system as claimed in claim 1, wherein the discharging unit comprises a cooling bin and a sealing discharge valve; The cooling bin receives the dried sludge from the high-temperature setting module, and reduces the temperature of the sludge to a safe storage temperature through heat exchange; and the sealed discharge valve intermittently discharges the cooled dried sludge to the outside of the system.
8. The drying method of the multi-stage sludge drying system according to any one of claims 1 to 7, which is characterized by comprising the following steps: s1, conveying a heat medium in a corresponding temperature interval to enable the internal temperature of each module to reach a preset process standby value; s2, enabling sludge to be dried to enter a feeding unit, shearing, crushing, mixing and homogenizing by a crushing and homogenizing device, and continuously and uniformly feeding the sludge into a low-temperature preheating module according to the initial flow; s3, sectional gradient drying treatment; S4, respectively collecting wet and hot gases generated by each module by a dehumidifying unit, and extracting sensible heat and latent heat by a heat recovery mechanism; S5, discharging the dried sludge from the tail end of the high-temperature shaping module, cooling the sludge in a cooling bin of a discharging unit, and discharging the sludge intermittently or continuously from the system through a sealed discharge valve after the temperature of the sludge is reduced to a safe storage temperature.
9. The drying method of the multistage sludge drying system according to claim 8, wherein the control unit in S5 dynamically adjusts the flow rate and the residence time of the cooling medium in the cooling bin according to the feedback data of the discharging temperature sensor.

Description

Multistage sludge drying system and drying method Technical Field The invention relates to the technical field of sludge waste treatment, in particular to a multi-stage sludge drying system and a drying method. Background Sludge is a main byproduct generated in the sewage treatment process, and has the characteristics of high water content, high viscosity, easy putrefaction, pathogen-containing property and the like. Desiccation is a key pretreatment link for sludge reduction, stabilization and recycling. The existing sludge drying technology often adopts a single high-temperature heat source, so that heat is wasted in a low-temperature preheating stage, and a large amount of latent heat is not effectively recovered due to the fact that moisture is quickly evaporated at a high temperature, and the change of physicochemical characteristics of the sludge in stages with different water contents is difficult to consider due to the lack of precise sectional temperature control; The discharged wet and hot gas is usually discharged directly or after simple treatment, and a large amount of sensible heat and latent heat contained therein is not recycled, resulting in energy waste. Disclosure of Invention The invention aims to overcome the technical defects and provide a multi-section sludge drying system and a drying method for carrying out sectional gradient heating according to sludge drying characteristics. In order to solve the technical problems, the technical scheme provided by the invention is that the multi-stage sludge drying system comprises a feeding unit, a multi-stage serial drying unit, a heat exchange circulation unit, a dehumidifying unit and a discharging unit; The multi-stage serial drying unit comprises a low-temperature preheating module, a medium-temperature evaporating module and a high-temperature setting module which are sequentially arranged, and the heat exchange circulation unit is respectively communicated with each module in the multi-stage serial drying unit and provides heat mediums with different temperature ranges for each module; the moisture removing unit is respectively communicated with each module in the multistage serial drying unit, and collects and discharges moisture in each module; the system also comprises a control unit which is respectively connected with the feeding unit, the multistage serial drying unit, the heat exchange circulation unit, the dehumidifying unit and the discharging unit in a signal way, and the sludge conveying speed, the heat medium parameters and the dehumidifying amount are controlled based on the obtained working conditions of the units. Preferably, the low-temperature preheating module, the medium-temperature evaporating module and the high-temperature shaping module are internally provided with independent stirring and conveying mechanisms, and each stirring and conveying mechanism comprises a driving motor, a transmission shaft and special-shaped stirring blades distributed along the axial direction; the pitch or the inclination angle of the special-shaped stirring blade is gradually changed along the flowing direction of the sludge. Preferably, the feeding unit comprises a sludge receiving hopper, a crushing and refining device and a quantitative feeder which are sequentially arranged; The crushing and homogenizing device is used for shearing, crushing, mixing and homogenizing the sludge, and the constant feeder is used for conveying the homogenized sludge to the low-temperature preheating module according to a set flow. Preferably, the heat exchange circulation unit comprises at least two independent heat medium generating devices and a heat medium mixing dispenser; The two heat medium generating devices respectively generate a low-temperature interval heat medium and a high-temperature interval heat medium, and the heat medium mixing and adjusting device mixes the heat mediums with different temperatures in proportion according to the instruction of the control unit to generate a medium-temperature interval heat medium. Preferably, the heat exchange circulation unit further comprises a circulation pump set, and the circulation pump set controls the flow of the heat medium to each module and circulates in a loop. Preferably, the dehumidifying unit comprises a dehumidifying port, a collecting pipe and a heat recovery mechanism, wherein the dehumidifying port is respectively communicated with the low-temperature preheating module, the medium-temperature evaporating module and the high-temperature shaping module, and the collecting pipe is connected with the multi-wet port; the heat recovery mechanism collects the hot and humid gas exhausted by each module and extracts sensible heat and latent heat from the hot and humid gas. Preferably, the discharging unit comprises a cooling bin and a sealing discharging valve; The cooling bin receives the dried sludge from the high-temperature setting module, and reduces the temperature of the sludge to a sa