﻿ 污泥高级厌氧消化前后的热风对流干燥特性
 上海理工大学学报  2020, Vol. 42 Issue (4): 354-360 PDF

1. 上海理工大学 环境与建筑学院，上海 200093;
2. 同济大学 环境科学与工程学院，上海 200092

Characteristics of advanced anaerobic digestion biogas residue by hot air convection drying
ZHAN Yong1, YE Huibin1, DONG Bin2, HUANG Yuandong1
1. School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China;
2. School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
Abstract: The convection drying experiments were carried out on the dewatered sludge and the advanced anaerobic digestion biogas residue by hot air convection drying technology. The effects of hot air temperature, flow rate, and sample thickness on sludge drying were investigated. The results show that the drying efficiency of sludge after the advanced anaerobic digestion is higher than that of dewatered sludge under the same conditions. The maximum drying rate of the advanced anaerobic digestion biogas residue was 486.2 mg/(g·min), which was 6 times of that of dewatered sludge 80.7 mg/(g·min) under the hot air temperature 120 ℃, flow rate 6 m/s and sample thickness 10 mm. In the actual treatment, the sludge may be first subjected to the advanced anaerobic digestion, and then reduced by means of drying.
Key words: sludge     advanced anaerobic digestion     anaerobic digestion residue     drying

1 材料和方法 1.1 试验材料 1.1.1 试验样品

1.1.2 试验仪器

1.2 试验方法 1.2.1 试验工况

1.2.2 试验方法

1.3 数据分析方法

 $M = \frac{{m_i} - {m_{\rm f}}}{{{m_{\rm f}}}} \times 100{\text{%}}$ (1)

 $MR = \frac{{{m_i} - {m_{\rm f}}}}{{{m_0} - {m_{\rm f}}}}$ (2)

 $DR = \frac{{{M_i} - {M_{i - 1}}}}{{\Delta t}}\times 10^{-3}$ (3)

2 结果与讨论 2.1 脱水污泥对流干燥试验结果分析 2.1.1 热风温度对脱水污泥干燥的影响

 图 1 SS0在不同热风温度下的湿分比 Fig. 1 Wet ratio of SS0 at different hot air temperatures

 图 2 SS0在不同热风温度下的干燥速率 Fig. 2 Drying rate of SS0 at different hot air temperatures

2.1.2 热风流速对脱水污泥干燥的影响

 图 3 SS0在不同热风流速下的湿分比 Fig. 3 Wet ratio of SS0 at different hot air flow rates

 图 4 SS0在不同热风流速下的干燥速率 Fig. 4 Drying rate of SS0 at different hot air flow rates

2.1.3 污泥样品厚度对脱水污泥干燥的影响

 图 5 SS0在不同样品厚度下的湿分比 Fig. 5 Wet ratio of SS0 at different sample thicknesses

 图 6 SS0在不同样品厚度下的干燥速率 Fig. 6 Drying rate of SS0 at different sample thicknesses

2.2 污泥高级厌氧消化沼渣对流干燥试验结果分析 2.2.1 热风温度对消化沼渣干燥的影响

SS1在热风流速4 m/s、样品厚度10 mm、不同热风温度的对流干燥情况下，其湿分比和干燥速率的变化情况如图7图8所示。

 图 7 SS1在不同热风温度下的湿分比 Fig. 7 Wet ratio of SS1 at different hot air temperatures

 图 8 SS1在不同热风温度下的干燥速率 Fig. 8 Drying rate of SS1 at different hot air temperatures

2.2.2 热风流速对消化沼渣干燥的影响

 图 9 SS1在不同热风流速下的湿分比 Fig. 9 Wet ratio of SS1 at different hot air flow rates

 图 10 SS1在不同热风流速下的干燥速率 Fig. 10 Drying rate of SS1 at different hot air flow rates

2.2.3 样品厚度对消化沼渣干燥的影响

 图 11 SS1在不同样品厚度下的湿分比 Fig. 11 Wet ratio of SS1 at different samples thicknesses

 图 12 SS1在不同样品厚度下的干燥速率 Fig. 12 Drying rate of SS1 at different sample thicknesses

3 结　论

a. 结合SS0和SS1自身的特性，可以发现：污泥经高级厌氧消化后产生的沼渣，其内部的部分细胞膜被破坏，使内部结合水释放出来变成了更易去除的自由水；污泥经高级厌氧消化后降低了自身的活化能，活化能越小，其干燥阻力越小。在实际工厂生产和工艺中，可考虑将污泥先经过高级厌氧消化后，再通过干化手段来减量，可大大缩短干化时间，减少干化成本。

b. 不论污泥样品的干燥实验工况和种类如何，干燥过程的基本规律都基本相似，按主要曲线规律可划分为两个阶段：升速阶段和降速阶段。在对流干燥过程中，热风温度、热风风速和样品厚度是能够作用导致干燥效果有所改变的几个重要要素。

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