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CN-121990707-A - Circulating water treatment system and method for preventing regenerated leather production water puncture needle head from being blocked

CN121990707ACN 121990707 ACN121990707 ACN 121990707ACN-121990707-A

Abstract

The invention discloses a circulating water treatment system and a method for preventing a regenerated leather production water puncture needle head from being blocked. The wastewater generated in the water jet strengthening process sequentially enters a clarification tank after water collection and sedimentation, screen filtering, air floatation treatment and fine filtration treatment, reuse water is obtained, terminal purification is carried out, the water jet strengthening process is carried out again, a saponification-sedimentation-neutralization integrated treatment process is further included between the air floatation treatment and the fine filtration treatment, the process is realized through a saponification-sedimentation-neutralization integrated facility, the integrated facility comprises a first group of integrated treatment units and a second group of integrated treatment units which are arranged side by side and controlled through valve switching, and the two groups of integrated treatment units alternately carry out water inlet, saponification, sedimentation, mud discharge, neutralization, water discharge and standing processes so as to realize continuous operation. The invention provides a simple and feasible saponification technical route based on the inherent cause of frequent blockage of the water jet device in the regenerated leather production, and solves the problem of blockage of the water jet needle head when the circulating water is recycled for a long time.

Inventors

  • DING CUICUI
  • JIANG AOXUE
  • LIU XUEPING
  • ZHANG MIN
  • CHEN RONGGUO

Assignees

  • 福建理工大学

Dates

Publication Date
20260508
Application Date
20251230

Claims (10)

  1. 1. The circulating water treatment method for preventing the blockage of the water felting needle head in the regenerated leather production process is characterized in that the circulating water treatment method further comprises a saponification-precipitation-neutralization integrated treatment process between the air flotation treatment and the fine filtration treatment, wherein the process is realized through a saponification-precipitation-neutralization integrated facility, the integrated facility comprises a first group of integrated treatment units and a second group of integrated treatment units which are arranged in parallel and controlled through valve switching, and the two groups of integrated treatment units alternately perform water inlet, saponification, precipitation, mud discharge, neutralization, water discharge and standing processes to realize continuous operation.
  2. 2. The method for treating circulating water for preventing a water needle head from being blocked as claimed in claim 1, wherein the saponification process is to pump alkali liquor into an integrated treatment unit filled with wastewater, the pumping is performed while stirring and monitoring pH, the pumping of alkali liquor is stopped and the stirring is stopped when the pH of wastewater exceeds 12, and the reaction time is 30±3min.
  3. 3. The method for treating circulating water for preventing a regenerated leather production water needle from being blocked according to claim 1, further characterized in that the precipitation step is to react lipid substances in the waste water with alkali liquor to form precipitate, and the precipitation time is not less than 30min.
  4. 4. The method for treating circulating water for preventing a regenerated leather production water needle head from being blocked according to claim 1, wherein the sludge discharging procedure is to arrange a sludge bucket, a sludge discharging pipeline and a sludge pipe valve at the bottom of an integrated facility, open a sludge pipe valve to discharge sludge in the sludge bucket, discharge sludge for 15+/-1 min, and close the sludge pipe valve after the sludge discharge is completed.
  5. 5. The method for treating circulating water for preventing a regenerated leather production water needle head from being blocked according to claim 1, wherein the neutralization step is to pump acid liquor into an integrated treatment unit, stir and monitor pH while pumping, and stop pumping acid liquor and stop stirring when the pH of wastewater is lower than 8, and the reaction time is 15+/-1 min.
  6. 6. The method for treating circulating water for preventing a regenerated leather production water needle head from being blocked according to claim 1, wherein the drainage procedure is to arrange a decanter in an integrated facility, and drain the waste water in the system to the subsequent procedure by using the decanter, wherein the drainage time is 15+/-1 min.
  7. 7. The method for treating circulating water for preventing a regenerated leather production water needle from being blocked according to claim 1, wherein the standing process is that a facility stands for the next water inlet, and the standing time is 15+/-1 min.
  8. 8. The method for treating circulating water for preventing a regenerated leather production water spike from being blocked according to claim 1, wherein the fine filtration treatment comprises mechanical filtration, sand filtration and fiber cloth bag filtration in sequence, and the terminal purification comprises mechanical filtration and sand filtration in sequence.
  9. 9. The circulating water treatment system for preventing the blockage of the regenerated leather production water felting needle head comprises a water outlet of a water felting strengthening process, a water collecting sedimentation tank, a screen filtering device, an air floatation device, a filtering unit, a clarifying tank and a terminal purifying unit which are sequentially connected, and is characterized by further comprising saponification-sedimentation-neutralization integrated facilities arranged between the air floatation device and the filtering unit, wherein the saponification-sedimentation-neutralization integrated facilities comprise a first group of integrated treatment units and a second group of integrated treatment units which are arranged in parallel and controlled by valve switching, and the two groups of integrated treatment units alternately perform water inlet, saponification, sedimentation, mud discharge, neutralization, drainage and standing processes so as to realize continuous operation.
  10. 10. The circulating water treatment system for preventing the blockage of the water jet needle head for producing regenerated leather according to claim 9, wherein the water collecting sedimentation tank is used for carrying out primary solid-liquid separation on the wastewater generated in the water jet strengthening process, and settling large-particle-size solid particles; The screen filtering device is used for intercepting suspended matters and fibers; the air floatation device is provided with PAC and PAM adding units, and is used for flocculating fine suspended matters and fibers and then removing the fine suspended matters and the fibers in an air floatation mode; The filtering unit comprises a mechanical filtering device, a sand filtering device and a fiber cloth bag filtering device which are connected in sequence and is used for carrying out physical fine filtration on the wastewater after the air floatation treatment; The clarifier is used for collecting water treated by the filtering unit as reuse water; The terminal purifying unit comprises a mechanical filtering device and a sand filtering device which are sequentially arranged, and is used for purifying the effluent of the clarification tank and returning to the water thorn reinforcing process for recycling.

Description

Circulating water treatment system and method for preventing regenerated leather production water puncture needle head from being blocked Technical Field The invention belongs to the technical field of industrial wastewater treatment, and particularly relates to a circulating water treatment system and method for preventing a regenerated leather production water puncture needle head from being blocked. Background The regeneration technology of the leather waste is a green technology for changing waste into valuable, and the method radically reduces environmental pollution and resource waste by converting leather solid waste into a high-value regenerated base material, not only obviously reduces raw material cost and waste treatment cost, creates considerable economic benefit, but also can produce products with uniform and customizable performances, and realizes win-win effect of environmental benefit and economic benefit. Currently, the process flow for manufacturing the regenerated leather by leather scraps mainly comprises a series of steps of fiber dissociation, pulping, lapping, water needling reinforcement, drying, shaping and the like. The water jet (hydroentanglement) reinforcing technology is to puncture the fiber net through high-speed micro water flow with an instantaneous impact force of 10-30MPa, so that leather fibers are fully entangled and laid under the pure physical action, and the leather fibers can be formed at one time without chemical adhesives, thereby thoroughly avoiding the problem of organic solvent residues and maximally retaining the natural strength and touch feeling of the collagen fibers. The hydroentanglement process is that the regenerated leather is raised from a fiber felt to a core transition point of a high-quality coiled material which can be cut, sewn and embossed. However, the water used in the link is huge, so that the wastewater is recycled after being treated, the inherent requirements of controlling the process cost and improving the operation efficiency are met, and the sustainable operation foundation stone of the whole process meeting the clean production standard is realized. The water jet technology is required to provide stronger impact force, so that the inner diameter of the needle in the device is smaller, most of the needles are between 100 and 120 mu m, and the needles are easy to block. Therefore, the interception treatment of suspended particles in the circulating water is a key for ensuring the continuous and stable operation of the process flow. The flow chart of the circulating water treatment process widely used by the current part of leather regeneration enterprises is shown in fig. 1, and wastewater generated in the water jet process firstly enters a water collecting sedimentation tank to naturally sediment larger solid particles (such as large-particle-size fibers, proteins and the like) so as to realize primary solid-liquid separation. The wastewater is then filtered through a screen to further retain the remaining suspended matter and fibers. Then, adding PAC (polyaluminum chloride) and PAM (polyacrylamide) into the wastewater, then entering a first air floatation working section, promoting fine suspended matters and fibers to flocculate into larger flocs, removing the large flocs in an air floatation mode, and then, enabling the wastewater to enter a second air floatation working section to deeply remove the residual suspended matters. After two-stage air floatation treatment, the wastewater enters a filtering system for physical fine filtration, and then flows into a clarification and recycling water tank for recycling. In order to ensure the water quality, the circulating water flowing back from the clarification tank is subjected to mechanical filtration and sand filtration to carry out terminal purification before being re-introduced into the water injection process. The circulating water treatment system realizes the removal of most micron-sized leather fiber, protein, tanning agent, dye and other solid organic and inorganic impurities in circulating water through the coagulation air floatation process and the like, can realize the normal operation of the circulating water system at the initial operation stage of the whole device (the production of regenerated leather with different colors, especially when in a light color system, fresh water is needed to be replaced), and after the circulating water circulates for a certain period of time (generally 0.5-1 month), the water pricking needle head starts to generate blocking phenomenon, so that the water pricking pressure is unstable, the quality of regenerated leather products (such as leather surface flaws and the like) is influenced, and even the frequent shutdown is needed to be replaced and cleaned (the replacement is needed once every 10-20 minutes of operation), so that the production continuity is seriously influenced, and the production efficiency is restricted. Therefore, finding