DAF machine has been widely used in water supply and drainage and wastewater treatment in recent years, and it can effectively remove the light floating flocs which are difficult to precipitate in the wastewater. Under a certain working pressure, air and water make the gas dissolve into the water to the maximum extent, and strive to be saturated. The sewage after the dosing reaction enters the mixing zone of the air flotation machine, and is mixed with the dissolved gas water after the release, so that the flocs adhere to the fine bubbles and then enter the air floating zone. The floc forms scum on the water surface under the action of air buoyancy. After the lower layer of clean water flows through the water collector to the clear water tank, a part of the clean water is returned to be used as dissolved gas, and the remaining clean water flows out through the overflow port. After the scum on the surface of the air floating pool gathers to a certain thickness, it is scraped into the scum tank by the scraper to discharge the water. The high-efficiency DAF machine is suitable for the treatment of industrial wastewater such as chemical, food, wool spinning, slaughtering, brewing, beneficiation and washing.

Background of the project

A non-staple food enterprise in Jiangsu is mainly engaged in the processing of canned yellow peaches, and its export share accounts for 10% of the national export volume. With the increase in canned output, the amount of wastewater has gradually increased, and the total amount of organic pollutants and solid waste has increased. In order to achieve the standard discharge, the company invites Runneng to transform the wastewater (including pickling water, caustic washing water and workshop flushing water) discharged during the production process. The original treatment process is as follows:

Application of DAF machine for canning industry original-wastewater-treatment-process

Runneng technicians used intensive pretreatment-hydrolysis acidification-aerobic biochemical treatment process according to the project conditions. On the basis of making full use of the original equipment, the transformation and expansion will be carried out, and three adjustment tanks will be added in the pretreatment section to pre-condition the pH of the wastewater. At the same time, two Runneng brand high-efficiency DAF machines, one mud removal machine and other equipments will be added. The reconstructed project has been comprehensively improved in terms of wastewater treatment capacity, stability, and compliance rate. Runneng brand high-efficiency DAF machine can produce tiny bubbles. The bubble size is small and the floating speed is slow, and most of the pectin can be floated out. At the same time, the air diffusing system is modified, so that the air diffuser is not easy to block. The improved process is as follows:

Application of DAF machine for canning industry improved-wastewater-treatment-process

Technical parameters of DAF machine

  • Model of DAF machine is RN-PRQF200
  • Treatment capacity is 200m3/h
  • Size of DAF machine is 13.2×3.4×2.8m
  • Total power is 17.5 kw
  • Mixer power is 2.2kw
  • Number of mixing machines is 2 sets
  • Matching device is PAC, PAM feeding device
  • Drug dissolution tank is 2m3
Application of DAF system for canning industry
Application of DAF unit for canning industry

At the end of November 2018, the high-efficiency DAF machines and other equipments were transported to Jiangsu customer site for installation and commissioning. Before the transformation, the effluent COD of the original wastewater treatment system was above 1000 mg/L, which was much higher than the design requirements for effluent.

After the transformation of our company, the effluent COD index is maintained at 50 ~ 150 mg / L, far below the COD <500mg / L standard. In addition, through the high-efficiency DAF machine reconstruction project, the problem that the pH of the wastewater tank adjustment pool is small and the pH cannot be stably adjusted is effectively solved, which provides a guarantee for the stable operation of the subsequent air flotation and biochemical system. Through the efficient operation of the high-efficiency air flotation machine, most of the pectin in the wastewater is removed, which greatly reduces the processing load of the subsequent biochemical system. Up to now, high-efficiency air flotation machines and other equipment have been running stably, with high degree of automation, and wastewater can reach standards. The process can be applied to wastewater treatment retrofits or new projects of various food processing enterprises.

About RUNNENG

Shandong RUNNENG Environmental Technology Co., Ltd (RUNNENG) had been dedicated to supplying one stop wastewater equipment and Water Resource Recovery Facility (WRRF) solutions to worldwide customers for over 20 years. RUNNENG has over 30 professional experts and more than 150 staffs. Our high quality innovative wastewater equipment includes dissolved air flotation equipmentbar screen waste remover, sludge scraper and integrated sewage treatment equipment, etc. All our wastewater equipment has been passed the certificates of ISO9001, ISO14001 and OHSAS18001, we also have the Grade B engineering design certificate issued by the Ministry of Environmental Protection. Hope to be your partner.

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