Sewage Sludge Flow and Drying Characteristics in Paddle Dryers

2013 ◽  
Vol 334-335 ◽  
pp. 365-368 ◽  
Author(s):  
Hou Lei Zhang ◽  
Xin Zhi Liu ◽  
Shu Guang Zhu ◽  
Bin Li
Keyword(s):  
Sewage Sludge ◽  
Inlet Temperature ◽  
Limited Data ◽  
Drying Characteristics ◽  
Sludge Disposal ◽  
Mass Flowrate ◽  
Energy Consuming ◽  
Sludge Drying ◽  
Thermal Oil ◽  
Monotonic Relation

Sewage sludge from wastewater treatment is being more and more produced in many countries. For sewage sludge disposal, drying operation is usually required and greatly energy-consuming. Paddle dryers, one kind of indirect dryers, are widely used in removing moisture of sewage sludge recently, but the design, to some extent, still depends on empirical and limited data. In this paper, we presented preliminary experimental results of sewage sludge drying based on a 3 m2paddle dryer prototype. The effects of thermal oil inlet temperature on outlet moisture content and mass flowrate of initial sludge are recorded and analyzed. A simple monotonic relation between mass flowrate of initial sludge and thermal oil inlet temperature does not exist. Besides, we performed the drying experiment of adding low-value biomass (rice husk) into wet sewage sludge. The results show that the drying performance is improved significantly.

scholarly journals Energy Recovery from Sewage Sludge: The Case Study of Croatia

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1927 ◽  
Author(s):  
Dinko Đurđević ◽  
Paolo Blecich ◽  
Željko Jurić
Keyword(s):  
Sewage Sludge ◽  
Energy Recovery ◽  
Fossil Fuels ◽  
Wastewater Treatment Plants ◽  
Energy Generation ◽  
Fuel Oil ◽  
Hard Coal ◽  
Solar Drying ◽  
Sludge Disposal ◽  
Sludge Drying

Croatia produced 21,366 tonnes of dry matter (DM) sewage sludge (SS) in 2016, a quantity expected to surpass 100,000 tonnes DM by 2024. Annual production rates for future wastewater treatment plants (WWTP) in Croatia are estimated at 5.8–7.3 Nm3/people equivalent (PE) for biogas and 20–25 kgDM/PE of sewage sludge. Biogas can be converted into 12–16 kWhel/PE of electricity and 19–24 kWhth/PE of heat, which is sufficient for 30–40% of electrical and 80–100% of thermal autonomy. The WWTP autonomy can be increased using energy recovery from sewage sludge incineration by 60% for electricity and 100% of thermal energy (10–13 kWhel/PE and 30–38 kWhth/PE). However, energy for sewage sludge drying exceeds energy recovery, unless solar drying is performed. The annual solar drying potential is estimated between 450–750 kgDM/m2 of solar drying surface. The lower heating value of dried sewage sludge is 2–3 kWh/kgDM and this energy can be used for assisting sludge drying or for energy generation and supply to WWTPs. Sewage sludge can be considered a renewable energy source and its incineration generates substantially lower greenhouse gases emissions than energy generation from fossil fuels. For the same amount of energy, sewage sludge emits 58% fewer emissions than natural gas and 80% less than hard coal and fuel oil. Moreover, this paper analysed the feasibility of sludge disposal practices by analysing three scenarios (landfilling, co-incineration, and mono-incineration). The analysis revealed that the most cost-effective sewage sludge disposal method is landfilling for 60% and co-incineration for 40% of the observed WWTPs in Croatia. The lowest CO2 emissions are obtained with landfilling and mono-incineration in 53% and 38% of the cases, respectively.

Effects of air parameters on sewage sludge drying characteristics and regression analyses of drying model coefficients

2021 ◽  
Vol 198 ◽  
pp. 117501
Author(s):  
Qiushuang Zheng ◽  
Ziyuan Hu ◽  
Penggang Li ◽  
Long Ni ◽  
Guanying Huang ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Regression Analyses ◽  
Drying Characteristics ◽  
Drying Model ◽  
Sludge Drying

Economic Optimization of Indirect Sewage Sludge Heat Dryer Unit for Sewage Sludge Incineration Plants

2015 ◽  
Author(s):  
Sinan Demir ◽  
Orkun Karabasoglu ◽  
V'Yacheslav Akkerman ◽  
Aysegul Abusoglu
Keyword(s):  
Sewage Sludge ◽  
Minimum Cost ◽  
Economic Optimization ◽  
Two Phase ◽  
Economic Relations ◽  
Sludge Incineration ◽  
Oil Tank ◽  
Sludge Drying ◽  
Two Phase Heat Transfer ◽  
Thermal Oil

This paper presents the economic optimization of indirect sewage sludge heat dryer for sewage sludge incineration plants. The objective function based on two-phase heat transfer, and economic relations is provided to demonstrate the optimum size for the minimum investment cost. De-watered sludge is fed into the dryer with a mass flow rate of 165 tons per day and consists of 27% dry matter. After the sludge drying process, the dryness of sludge increases up to 40%. In the indirect sludge dryer unit, thermal oil is used to heat the dryer wall and to prevent heat loss. Thermal oil is circulated in a closed cycle and gathered into an oil tank. Total cost of the sludge dryer unit changes proportional to the dryer area. The optimum dryer area is found as 32.54 m2. The corresponding minimum cost is found as $35,700.

Concept for an interlinked system of a sludge drying facility and a landfill for residual waste

1998 ◽  
Vol 38 (2) ◽  
pp. 119-125 ◽  
Author(s):  
P. Brautlecht ◽  
S. Gredigk
Keyword(s):  
Sewage Sludge ◽  
Rural Areas ◽  
Biological Treatment ◽  
Synergistic Effects ◽  
Electric Energy ◽  
Negative Effects ◽  
Sludge Disposal ◽  
Sludge Drying ◽  
Very High ◽  
Joint Treatment

The integration of a sewage sludge drying facility into landfill operation leads to a large number of synergistic effects. Two of these modules are examined more closely in this paper. If the thermal and electric energy produced in landfill operation are used for sewage sludge drying, the drying costs will be able to be reduced and the existing resources will be used in an ecologically acceptable way throughout the year. The joint treatment of the vent condensates resulting from sewage sludge drying and of landfill leachate suggests itself because both wastewaters show a similar composition. Tests carried out for this purpose have revealed that the efficiencies achieved especially in joint biological treatment are very high due to the good biodegradability of the vent condensates. Negative effects from the joint treatment of vent condensates on other procedures examined were not observed. With the help of comprehensive interlinked systems sewage sludge drying can even be realized in rural areas. This contributes to higher safety in sewage sludge disposal under economic, ecological and future-oriented aspects.

Research on Drying Characteristics of Sewage Sludge by Indirect Heating Device using Thermal Oil

2014 ◽  
Vol 31 (5) ◽  
pp. 574-580 ◽  
Author(s):  
Seon Jai Baik ◽  
◽  
In Sup Han ◽  
Seoung Min Hong ◽  
Sung Hyo Kang
Keyword(s):  
Sewage Sludge ◽  
Drying Characteristics ◽  
Heating Device ◽  
Thermal Oil ◽  
Indirect Heating

scholarly journals Drying characteristics of wastewater sludge according to outside air inflow conditions

2018 ◽  
Author(s):  
Sang Hyun Oh ◽  
Ki Ho Park ◽  
Byoung Hyuk Yu ◽  
Sung Il Kim
Keyword(s):  
Thin Film ◽  
Sewage Sludge ◽  
Wastewater Sludge ◽  
Drying Process ◽  
Drying Characteristics ◽  
Inflow Condition ◽  
Materials Used ◽  
Sludge Drying ◽  
Drying Efficiency ◽  
Inflow Conditions

The purpose of this study is to analyze the changes of drying efficiency according to the inflow conditions of outside air into the drying equipment during the drying process in order to reduce the energy used in the drying process of sludge. We conducted the experiment using a vertical thin film dryer. Materials used for the experiment are sewage sludge. As a result of the study, higher drying efficiency was obtained in the case of outside air inflow than in the case of no outside air inflow. In addition, optimum condition of outside air inflow was derived. Keywords: Drying; Sludge; Drying efficiency; Air inflow condition 

The Concentration and the Abatement Strategy of Organic Contaminants in Sewage Sludge Dewatering

2011 ◽  
Vol 356-360 ◽  
pp. 1495-1499
Author(s):  
Jie Yu ◽  
Guo Di Zheng ◽  
Tong Bin Chen
Keyword(s):  
Sewage Sludge ◽  
Organic Contaminants ◽  
Environmental Risks ◽  
Future Research ◽  
Sludge Dewatering ◽  
Sludge Disposal ◽  
Secondary Pollution ◽  
Pollution Problem ◽  
Safety And Environment ◽  
Abatement Strategy

Sludge agriculture application in future will be one of the main sewage sludge disposal ways in China. To ensure safety and environment of sewage sludge agriculture application, except to strengthen the research of sludge heavy metal, pathogen outside the organic contaminants will be one of the focuses of the future research, especially to strengthen the PAHs and NP/NPE. In order to reduce the environmental risks of sludge agriculture application, using biological aerobic fermentation processing technology treatment sludge can effectively reduce the organic contaminants, depress secondary pollution problem, which sewage sludge brings.

Sign in / Sign up

Export Citation Format

Share Document