Drying Technology
Project Planner：Guangzhou SHINCCI Energy Equipment Co., LTD.
Service Object：The deep dewatering project of sludge of the second sewage treatment plant in Zhengzhou Port District
Time Period：May. 2018- Oct. 2018
Zhongyuan Environmental Protection Zhengzhou Airport Zone Second Sewage Treatment Plant
From sludge conditioning, reduction, drying to resource utilization, a four-in-one closed-loop heat pump low-temperature drying technology is created to form a systematic solution for sludge disposal.
【Guide】：The sludge deep dewatering project of the Second Sewage Treatment Plant in Zhengzhou Port District can dry the sludge to a moisture content of about 10-30% with only a small amount of electricity, which can reduce the discharge of hazardous waste while achieving good economic benefits. . Thorough removal of water, clean water, the entire drying process is energy-saving, intelligent, and environmentally friendly, and pollutant emissions are almost zero. As a demonstration project of sludge treatment in Zhengzhou, it has been highly recognized by government leaders and environmental protection authorities.
Sludge treatment Technical Solution
In response to the various shortcomings of the current sludge drying, Zhongyuan Environmental Protection started to work with Guangzhou Shincci Energy Equipment Co., Ltd. to study comprehensive sludge treatment solutions in March 2016.
As the leader of low-temperature sludge drying technology, Shincci has been focusing on research and application in the field of environmental protection energy for many years. The self-developed low-temperature evaporative condensation dehumidification technology has made great progress in the field of sludge drying, and both parties have good complementarity. , Then established a joint technical research team.
Through cooperation and cooperation, the two parties have jointly solved the joint debugging and joint test of the complete set of systems such as the dosing flocculation unit, the front-end dehydration unit, the low-temperature drying unit and the discharge storage and transportation unit, and efficiently reduced the moisture content of the sludge to 5 -30% interval (adjustable). The dried mud after drying is granular, stable in nature, convenient for storage and transportation, and various subsequent disposal methods can be selected according to the specific needs of resource utilization.
The sludge to be treated in this project adopts the integrated process of sludge conditioning, dewatering and drying: new ZTS conditioner → 95% moisture content of the original sludge → dehydrator (centrifuge/plate frame machine/belt filter press) → Closed low-temperature drying system → sludge moisture content (adjustable from 5% to 30%) → dry material storage system → sent to the power plant for mixed combustion with coal. It can realize that the sludge is not shipped out of the factory, and is resourced on the spot, avoiding the cost of transportation and environmental pollution, and completely solving the problem of sludge outlet that plagues various places.
The second sewage treatment plant of Zhengzhou Airport Zone of Zhongyuan Environmental Protection is located to the east of the planned New 107 National Road and to the north of Shanjia Village, Bagang Town, Zhongmou County. Factory Pollutant Discharge Standard" Class A standard. __↑
Over View of Sludge Drying Project
The design scale of Shincci sludge low-temperature drying system: 30t/d, the moisture content of the incoming sludge is about 65-70%, and the drying is below 30%. Equipment selection: SBDD9600FL (two sets), working time: 24 hours; engineering unit Mainly include: sludge drying workshop, incoming and outgoing material conveying system, low-temperature sludge drying equipment system, electrical, instrument automatic control, dry material collection system and other facilities.
Project Features
Small area: 40-100 square meters, each ton of mud covers an area of about 4 square meters, which can be stacked up and down
Investment province: The investment is only about 13 million yuan. Taking a 100.000-ton/day sewage treatment plant with an average daily output of 100 tons of sludge (80% moisture content) as an example, the direct operating cost is about 130 yuan/ton
No environmental impact: airtight drying, no odor and heat transfer to the outside world
Short construction period: 3-6 months construction period without complicated civil structure
Complete resource utilization: There is no loss of organic components during the drying process, and the dry material has a high calorific value, which can be all used for power generation in power plants.
The sewage collected from the port area passes through the sludge thickening tank, sludge storage tank, conditioning tank, dosing room, dehydration room and other facilities. After multiple purifications, it has become clear and transparent reclaimed water without odor. __↑
The sludge dewatering frame machine was put into operation in 2013.
The original design plan is that the moisture content of the mud is about 97% after gravity concentration.
Add lime and iron salt for conditioning, and then enter the frame machine for dehydration.
The size of the frame machine is 450 square meters, each ton of absolutely dry sludge needs to add 200 kg of lime and 50 kg of iron salt.
Before Project Transformation
At the beginning of 2016. Zhongyuan Environmental Protection developed a new type of sludge conditioner. The sludge after conditioning by this conditioner is significantly separated from the sludge and the filter press is dehydrated smoothly. The filtered water is clear, the mud cake is full and dry, and the moisture content can be reduced to 60% Below, the cost of sludge treatment before chemical transformation is equivalent to 0.085 yuan per ton of water.
After Project Transformation
After transformation, it is equivalent to 0.06 yuan per ton of water. Regardless of the amount of addition, the conditioning time, the processing amount or the cost-effectiveness ratio, this conditioning agent has unparalleled advantages. Especially the obvious change in the dosage, under normal circumstances, only 10 kg of pure liquid conditioner is added per ton of dry mud without increasing the amount of dry mud. The traditional iron salt lime conditioner, the total dosage is often 300 to 350 kg. Due to the small addition amount, the drug delivery cycle of this sludge conditioner is greatly prolonged; the pure liquid product shape also makes the drug filling convenient and fast, and the labor and equipment requirements are low; because the chemical is environmentally friendly, non-toxic, non-corrosive, and loss of equipment It is greatly reduced and the filter cloth is not easy to be clogged; the mud cake does not introduce harmful substances and does not change the properties of the sludge, making the subsequent disposal of the sludge easier (whether it is composting or drying), and there are more choices and possibilities.
Sludge Drying
Drying is a kind of deep dehydration, which is different from physical dehydration. It is a process of removing most of the water from the sludge through percolation or evaporation.
Since this process evaporates the bound water and internal water that are difficult to separate out, the drying process in the traditional sense often means a process with high energy consumption. At present, conventional drying methods mainly use various heat materials to directly or indirectly heat and dry. In addition, solar energy, biological composting, chemical mixing and drying, natural drying, etc. are also used to dry sludge, and these drying processes are It has the disadvantages of huge energy consumption, low efficiency, and serious pollution to soil, air and water.
Dried Sludge Disposal
The sludge closed-loop heat pump low-temperature drying unit independently developed by Shincci is a device that uses the refrigeration system to cool and dehumidify the hot and humid air, and at the same time recovers the moisture in the air through the principle of heat pump to condense the latent heat of the air. The final product in the sludge closed-loop low-temperature thermal dryer can be used as fuel for power generation in thermal power plants.
After the power plant mixed burning test, the power plant gave the experimental conclusions that after the sludge mixed burning test, the generator set is operating normally, has no adverse effects on the boiler combustion, and has relatively good combustion-supporting characteristics. In this way, the problem of sludge disposal in the sewage treatment plant can be fundamentally solved, and a way out for the recycling of sludge can also be found.
Project implementation effect
Through the application of these technologies, valuable land resources can be saved, water and soil environment can be effectively protected, and social, environmental and economic benefits can be achieved. A lot of effort has been devoted to scientific research personnel. At the same time, this new technology that benefits the country and the people can also provide a technical demonstration model for municipal sludge treatment and can be promoted nationwide.
