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CN-121974511-A - System and method for treating and recycling back flushing water of carbon steel continuous casting filter

CN121974511ACN 121974511 ACN121974511 ACN 121974511ACN-121974511-A

Abstract

The invention belongs to the technical field of steelmaking cooling water supply, and provides a back flushing water treatment and recycling system of a carbon steel continuous casting filter and a use method thereof, aiming at the multi-medium filter back flushing water of the carbon steel continuous casting turbid circulating water treatment system, so that the water quality of the back flushing water reaches the recycling standard, and the back flushing water is recycled, thereby changing waste into valuable. The method reduces the treatment load of downstream water treatment procedures, reduces the difficulty of water treatment, ensures that the quality of the downstream sewage is relatively simple without too complicated treatment, reduces the water treatment cost, maintains the water balance of a small circulation system of steelmaking cooling water, reduces the water supplementing quantity, reduces the consumption of new water, saves the water taking cost, reduces the fluoride ions in the water body and protects the environment.

Inventors

  • WU YANQIN
  • LI WENJUN
  • LIU ZIANG

Assignees

  • 山西太钢不锈钢股份有限公司

Dates

Publication Date
20260505
Application Date
20260120

Claims (10)

  1. 1. A back flushing water treatment and recycling system of a carbon steel continuous casting filter is characterized by comprising a slurry tank and a concentration tank, wherein a filter material interception device is arranged at a water inlet position of back flushing wastewater of the slurry tank and used for intercepting filter materials in the back flushing wastewater, a slurry pump is arranged in the slurry tank in a matched mode and used for pressurizing and lifting back flushing wastewater and sludge in the slurry tank to the concentration tank, a dosing system is arranged above the slurry tank, a dosing metering pump of the dosing system is used for dosing a medicament, a stirrer is arranged in the slurry tank and used for fully mixing the medicament and the wastewater, a thickener is arranged in the concentration tank and used for scraping mud and oil at the bottom of the concentration tank, a collector is arranged at the center of the bottom of the concentration tank and used for collecting the sludge scraped by the thickener, a diaphragm pump is arranged below the collector and used for compressing and transporting the concentrated and precipitated sludge to a plate-frame filter press, a supernatant overflow pipe and an oil collection device are arranged above the concentration tank and connected with the advection tank, the oil collection device is connected to the plate-frame filter press, and the bottom of the concentration tank and the front end of a reaction zone are arranged.
  2. 2. The back flushing water treatment and recycling system of the carbon steel continuous casting filter, which is characterized in that the effective volume of the concentration tank is matched with the back flushing wastewater amount of the filter, so that the hydraulic retention time is more than or equal to 4 hours.
  3. 3. The back flush water treatment and recycling system of a carbon steel continuous casting filter as claimed in claim 1, wherein the filter material interception device is made of stainless steel wire mesh with 1-2mm holes and flat steel.
  4. 4. The back flush water treatment and recycling system of the carbon steel continuous casting filter, as set forth in claim 1, wherein the installation direction of the scraper of the thickener is 45 degrees inward of the center.
  5. 5. The back flush water treatment and recycling system of the carbon steel continuous casting filter, as set forth in claim 1, wherein the diaphragm pump is a pneumatic diaphragm pump capable of realizing low flow and high concentration.
  6. 6. The method for using the back flush water treatment and recycling system of the carbon steel continuous casting filter, which is disclosed in claim 1, comprises the following steps: S1, collecting backwash wastewater through a filter material interception device and entering a slurry pond; S2, a dosing metering pump of a dosing system is used for controlling dosing of a water treatment agent, and a stirrer is used for stirring the agent and backwash wastewater to be fully mixed, wherein the water treatment agent comprises a flocculating agent, an oil removing agent, a bactericide and a defluorinating agent, and the flow of the dosing metering pump is adjustable and is adjusted according to the flow of the backwash wastewater; S3, starting a slurry pump to pressurize and lift backwash wastewater and sludge in the slurry tank to a concentration tank for precipitation and deoiling, wherein the slurry pump is controlled by frequency conversion, and the frequency of the slurry pump is linked with the liquid level of the slurry tank to control the slurry flow; s4, flocculating suspended matters in the sewage into large alum blossom under the action of a flocculating agent, settling the alum blossom into a collector at the bottom of a concentration tank, and floating the residual oil in the sewage to the water surface after separating the oil from water under the action of an oil removing agent; s5, the diaphragm pump sends the sludge in the collector to a plate-and-frame filter press to form sludge cake outward transportation treatment; s6, scraping the oil floating on the water surface to an oil collecting device by a scraping plate of the thickener, and discharging the oil to a plate-and-frame filter press to form mud cake outward transportation treatment; s7, flowing the supernatant to a advection pool through a supernatant overflow pipe for backflow and reutilization.
  7. 7. The method for using the backwashing water treatment and recycling system of the carbon steel continuous casting filter, which is disclosed in claim 6, is characterized in that the flocculating agent is divided into 2 groups of dosing metering pumps, each group is divided into 2, one is used for standby, the concentration of the flocculating agent is ensured to be 50ppm, the degreasing agent is an degreasing agent TS-52675, one is used for standby, the concentration of the degreasing agent is ensured to be 50-100 ppm, the bactericide is alternately used by adopting an oxidizing bactericide and a non-oxidizing bactericide, and the defluorinating agent is prepared by adopting a main agent calcium chloride to be mixed with a small amount of polyaluminium chloride or polyacrylamide.
  8. 8. The method for using the back flush water treatment and recycling system of the carbon steel continuous casting filter as set forth in claim 6, wherein the reaction process ensures that the PH value of the slurry tank and the concentration tank is controlled to be 6.8-7.2.
  9. 9. The method of using a back flush water treatment and recycling system for a carbon steel continuous casting filter as set forth in claim 6, wherein the sludge precipitated at the bottom of the concentration tank continuously flows back to the front end of the reaction zone according to a volume ratio of 10% -20%.
  10. 10. The method for using the backwashing water treatment and recycling system of the carbon steel continuous casting filter, which is disclosed in claim 6, is characterized in that 2 pneumatic diaphragm pumps are arranged, one pneumatic diaphragm pump is used for standby, the sludge is continuously discharged at low flow rate for 24 hours, and the sludge is treated by a plate-and-frame filter press, so that the water content reaches below 50% and can be transported to the outside for incineration.

Description

System and method for treating and recycling back flushing water of carbon steel continuous casting filter Technical Field The invention belongs to the technical field of steelmaking cooling water supply, relates to recycling of back flushing water of a carbon steel continuous casting filter, and particularly relates to a back flushing water treatment and recycling system and method of the carbon steel continuous casting filter. Background The process route of the carbon steel continuous casting turbid circulating water treatment is mature. The main route is mainly that backwater swirling flow sedimentation, a primary lift pump, a advection pool, a water absorbing well, a water pool, a secondary lift pump, a multi-medium filter, a cooling tower, a circulating water pool, a water supply pump and steel blank spraying. Wherein, the filter material function of the multi-medium filter is invalid after filtering for a period of time and needs to be backwashed and regenerated, and the backwashed sewage is directly discharged, and the incomplete failure frequently occurs due to the incomplete water treatment facilities and the untreated sewage is directly discharged into a factory drainage system. The method brings treatment pressure to the downstream water treatment process, and the water balance of the system is destroyed after the backwash water is discharged, so that a large amount of new water is needed to be supplemented in the system, the new water is wasted, and the water resource recycling concept is not well practiced. Disclosure of Invention The invention aims to provide a back flushing water treatment and recycling system and method for a carbon steel continuous casting filter, which aim at treating and recycling multi-medium filter back flushing water of the carbon steel continuous casting turbid circulating water treatment system, reduce the consumption of new water and save water resources. The technical scheme adopted by the invention for achieving the purpose is as follows: A back flushing water treatment and recycling system of a carbon steel continuous casting filter comprises a slurry tank and a concentration tank, wherein a filter material interception device is arranged at a water inlet position of back flushing wastewater of the slurry tank and used for intercepting filter materials in the back flushing wastewater, a slurry pump is arranged in the slurry tank in a matched mode and used for pressurizing and lifting back flushing wastewater and sludge in the slurry tank to the concentration tank, a dosing system is arranged above the slurry tank, a dosing metering pump of the dosing system is used for dosing a medicament, a stirrer is arranged in the slurry tank and used for fully mixing the medicament and the wastewater, a concentrator is arranged in the concentration tank and used for scraping mud and oil at the bottom of the concentration tank, a collector is arranged in the center of the bottom of the concentration tank and used for collecting the sludge scraped by the concentrator, a diaphragm pump is arranged below the collector and used for pumping the concentrated and precipitated sludge to a plate-frame filter press for compression and outward transportation, a supernatant overflow pipe and an oil collection device are arranged above the concentration tank and connected with the advection tank, the oil collection device is connected to a plate-frame filter press, and the bottom of the concentration tank and the front end of a reaction zone are provided with a sludge backflow pipe. Furthermore, the effective volume of the concentration tank is matched with the backwash wastewater amount of the filter, so that the hydraulic retention time is more than or equal to 4 hours. Further, the filter material interception device is made of stainless steel wire mesh with holes of 1-2mm and flat steel. Further, the scraper blade of the thickener is installed at an angle of 45 degrees inwards of the center. Furthermore, the diaphragm pump adopts an air-driven diaphragm pump which can realize low flow and high concentration. The application method of the back flush water treatment and reuse system of the carbon steel continuous casting filter comprises the following steps: S1, collecting backwash wastewater through a filter material interception device and entering a slurry pond; S2, a dosing metering pump of a dosing system is used for controlling dosing of a water treatment agent, and a stirrer is used for stirring the agent and backwash wastewater to be fully mixed, wherein the water treatment agent comprises a flocculating agent, an oil removing agent, a bactericide and a defluorinating agent, and the flow of the dosing metering pump is adjustable and is adjusted according to the flow of the backwash wastewater; S3, starting a slurry pump to pressurize and lift backwash wastewater and sludge in the slurry tank to a concentration tank for precipitation and deoiling, wherein the slurry pump is cont