CN102910774A

CN102910774A - Sewage treatment method of artificial board production system

Info

Publication number: CN102910774A
Application number: CN2012104207401A
Authority: CN
Inventors: 景玉国
Original assignee: TIANHUA DENSITY BOARD CO Ltd
Current assignee: TIANHUA DENSITY BOARD CO Ltd
Priority date: 2012-10-30
Filing date: 2012-10-30
Publication date: 2013-02-06
Anticipated expiration: 2032-10-30
Also published as: CN102910774B

Abstract

The invention relates to a sewage treatment method of an artificial board production system and belongs to the technical field of artificial board production environmental protection and comprehensive utilization. The technical scheme includes that the sewage treatment method is characterized by including: collecting sewage of the artificial board production system, feeding sewage subjected to mechanical impurity separation into a sewage evaporator, feeding steam generated after sewage evaporation into a hot-grind process of the artificial board production system, precooking and cooking fibers or wood chips, substituting the steam generated by sewage evaporation for high-quality steam, and using the sewage as resources to be fully utilized. The sewage treatment method of the artificial board production system has the advantages that by utilizing the process condition and the requirement that artificial board raw materials of the artificial board production system need to be cooked by steam, the sewage produced by artificial boards is evaporated to steam substituting for outside steam to use and is changed to be the resources for recycling, and the method is simple, feasible, less in investment and low in cost, has extremely high practicality and implementation, and is capable of turning the sewage into the resources to be fully utilized.

Description

The treatment process of a kind of Wood-based Panel Production system sewage

Technical field

The present invention relates to the treatment process of a kind of Wood-based Panel Production system sewage, belong to Wood-based Panel Production environmental protection and comprehensive utilization technique field.

Background technology

The sewage that produces in the building board production process is mainly raw material washing draining, the cork screw expressed waters such as wood chip; Except containing a large amount of suspended substances such as silt particle, bark, wood fragments, fiber, wood powder etc., also contain the extractum of Activities of Some Plants fiber such as Mierocrystalline cellulose, lignin, resene compound etc. in the sewage; The resene compound comprises resinous acid, longer chain fatty acid, tannins compound etc.This type of waste water has organism, characteristics that concentration of suspension is higher, belongs to more unmanageable high concentrated organic wastewater.This part waste water can not directly discharge, and must just can efflux after up to standard through processing.The traditional treatment process of this type of sewage is generally adopted the operations such as pre-treatment, anaerobic biological processing, aerobic treatment and sludge treatment, in treating processes, need to add more coagulating agent, flocculation agent, acid, alkali and other auxiliary agents etc.; Main Problems is that investment is large, processing cost is high, complicated operation, and outer draining index is unstable, is easy to environment; The process flocculation sediment parts such as organic compound such as Mierocrystalline cellulose, lignin, resene enter in the mud in the waste water simultaneously, a part is decomposed into carbonic acid gas through biochemical treatment, and the indexs such as water COD, BOD after processing are up to standard but the obvious increase of salts substances concentration can't realize whole recyclings, caused the waste of the organic compound resources such as Mierocrystalline cellulose in water resources and the water, lignin, resene.

For above problem, someone has proposed zero discharge of wood chip washing waste water technique, for example: China Patent No. 201110328244.9 is described, mainly there is the problem of following two aspects in this technique: the one, when the water ratio of raw material hangs down, general relative water content≤50%(weight percent) time, it is few that cork screw is extruded the water yield, and the chip washing circulating water system can consume this part water yield, can realize sewage zero-discharge; But, when too wet or water ratio is too high when raw material, general relative water content〉the 50%(weight percent) time, it is large that cork screw is extruded the water yield, and the chip washing circulating water system can't consume this part water yield, causes circulating water system to be risen, be forced to efflux, cause environmental pollution.The 2nd, contain the mechanical impuritys such as silt particle, bark, wood fragments, fiber, wood powder in the recirculated water of chip washing circulating water system, contain equally part wood extractive such as Mierocrystalline cellulose, lignin, resene compound, when recirculated water is carried out the mechanical impurity separation, need to add the medicaments such as coagulating agent, flocculation agent or other auxiliary agents, most of Mierocrystalline cellulose in the recirculated water, lignin, resene compound enter in the mechanical impurity through flocculation sediment, when increasing processing cost, also caused the waste of the organic compound resources such as the Mierocrystalline cellulose in the water, lignin, resene.

Summary of the invention

The treatment process that the purpose of this invention is to provide a kind of Wood-based Panel Production system sewage, sewage collecting with the Wood-based Panel Production system, carry out sending into contaminated water evaporator after mechanical impurity separates, the steam that produces behind the sewage evaporation is sent into the heat mill process of Wood-based Panel Production system, carry out pre-boiling, the boiling of fiber or wood chip, replace the steam of high-quality with the steam of waste water evaporation generation, sewage is all utilized as resource, water saving, environmental protection, synergy solve the problems referred to above that exist in the background technology.

The object of the present invention is achieved like this:

The treatment process of a kind of Wood-based Panel Production system sewage, comprise following processing step: the sewage collecting that 1. the Wood-based Panel Production system is discharged is to storage tank, again through pressurizeing with transferpump after filtration, the deoxygenation, send into the steam that contaminated water evaporator produces 0.5-1.6MPa, like this, when the water in the sewage was evaporated to steam, most of organism miscible in the sewage evaporated with water; 2. the steam that produces is used for the heat mill process of Wood-based Panel Production system, steam is softening raw material in heat mill process, and enter the drying process of Wood-based Panel Production system with me fibrous slurry, along with the reduction of fiber moisture and the decline of fiber temperature, organism a small amount of in the steam deposits to again fiber surface, turn back in the wood-based panel product, this part organism can play the effect of tackiness agent, reduces the consumption of wood-based plate synthetic adhesive; 3. the contaminated water evaporator sewer is through cooling, filtration, and the impurity that leaches is recycled, and the clear water that leaches returns contaminated water evaporator again and recycles; Both saved water resources, again decrease processing cost, simultaneously the partial organic substances in the sewage has been carried out recycle as resource.

The steam that contaminated water evaporator produces only for the heat mill process of Wood-based Panel Production system, does not enter steam pipe system because contain the more impurity such as organism.The quantity of steam that every cube of wood-based plate of heat mill process needs is 0.4-0.5t, the sewage quantity of every cube of wood-based plate discharging of Wood-based Panel Production system is 0.1-0.3t, Wood-based Panel Production system quantity of wastewater effluent is lower than the quantity of steam that heat mill process needs, sewage all evaporates the steam that produces and can all be consumed by heat mill process, insufficient section is by external pipe network steam supply, perhaps adopt fresh water to replenish the deficiency of the contaminated water evaporator water yield, can realize very easily the sewage zero-discharge of Wood-based Panel Production system.

The thermal source of contaminated water evaporator can adopt the external thermals source such as external steam, high-temperature flue gas, also can adopt combustion gas, fire coal, biomass-burning etc. as thermal source.

The water amount of blowdown of contaminated water evaporator and the weight percent of steam output are 1-10%.

Organism in the described sewage comprises Mierocrystalline cellulose, lignin, resene compound etc.; The resene compound comprises resinous acid, longer chain fatty acid, tannins compound etc., and boiling point generally is lower than 200 ℃; Vapor pressure 0.5-1.6MPa, vaporization temperature are about 150-210 ℃, and the organism overwhelming majority that boiling point is lower than vaporization temperature enters in the steam with evaporation of water; Boiling point is higher than the organism of vaporization temperature, and because of the gas stripping of steam, major part also can enter into steam with evaporation of water; These organism major parts are binder constituents natural in the plant, are recovered in the vegetable fibre, are conducive to improve the quality of wood-based plate, the consumption of reduction synthetic adhesive.

The present invention is applicable to density board, shaving board and the artificial board production system take all kinds of vegetable fibres as raw material.

Positively effect of the present invention is: utilize Wood-based Panel Production system raw material of artifical plate to need processing condition and the requirement of steam boiling, the sewage that wood-based plate is produced evaporates and becomes steam and replace external steam to use, sewage is become resource circulation utilization, simply, easily go, have very strong practicality and exploitativeness, less investment, cost are low, and sewage is all utilized as resource, turn waste into wealth.

Description of drawings

Accompanying drawing 1 is embodiment of the invention process flow sheet.

Embodiment

By the following examples, the invention will be further described

Embodiment: adopt the present invention to be applied to produce daily the medium density fibre board (MDF) production system that 500 sides are provided with the chip washing device.

50 tons of chip washing operation day sewage effluent amounts, cork screw day 30 tons of sewage effluent amounts, approximately 10 tons of other sewage quantities every days, add up to approximately 90 tons/day, hour sewage quantity 3.75t.

Contaminated water evaporator is arranged on the exhanst gas outlet of Wood-based Panel Production system biological matter heat-conducting oil furnace, thermal source is 400-500 ℃ flue gas, the evaporating pressure 0.9-1.2MPa(gauge pressure of contaminated water evaporator), vaporization temperature 170-190 ℃, the saturation steam amount 3.5t/h that produces sends into heat mill process and uses, heat mill process steam total requiremants is about 8t/h, and insufficient section 4.5t/h is replenished by steam pipe system.

The mechanical impurity water ratio that filters out in the sewage is the 70-90%(weight percent approximately), every day is the 2.0t(butt approximately) drop to through airing or secondary extrusion water ratio that the fuel as the biomass heat-conduction oil oven uses below 50%, whole Wood-based Panel Production system quantity of wastewater effluent is zero; Ton sewage current consumption 0.1-1kwh does not have other reagent consumptions, and working cost is very low, and year days running calculated by 300 days, and annual water-saving amount is more than 2.5 ten thousand tons.

Claims

1. the treatment process of a Wood-based Panel Production system sewage, it is characterized in that comprising following processing step: the sewage collecting that 1. the Wood-based Panel Production system is discharged is to storage tank, again through pressurizeing with transferpump after filtration, the pre-treatment, send into the steam that contaminated water evaporator produces 0.5-1.6MPa, when the water in the sewage was evaporated to steam, most of organism miscible in the sewage evaporated with water; 2. the steam that produces is used for the heat mill process of Wood-based Panel Production system, steam is softening raw material in heat mill process, and enter the drying process of Wood-based Panel Production system with me fibrous slurry, along with the reduction of fiber moisture and the decline of fiber temperature, organism a small amount of in the steam deposits to again fiber surface, turn back in the wood-based panel product, this part organism can play the effect of tackiness agent, reduces the consumption of wood-based plate synthetic adhesive; 3. the contaminated water evaporator sewer is through cooling, filtration, and the impurity that leaches is recycled, and the clear water that leaches returns contaminated water evaporator again and recycles.

2. the treatment process of described a kind of Wood-based Panel Production system sewage according to claim 1 is characterized in that the steam that contaminated water evaporator produces, and only for the heat mill process of Wood-based Panel Production system, does not enter steam pipe system; The quantity of steam that every cube of wood-based plate of heat mill process needs is 0.4-0.5t, the sewage quantity of every cube of wood-based plate discharging of Wood-based Panel Production system is 0.1-0.3t, the sewage quantity of Wood-based Panel Production system discharging is lower than the quantity of steam that heat mill process needs, sewage all evaporates the steam that produces and is all consumed by heat mill process, insufficient section is by external pipe network steam supply, perhaps adopt fresh water to replenish the deficiency of the contaminated water evaporator water yield, realize the sewage zero-discharge of Wood-based Panel Production system.

3. the treatment process of described a kind of Wood-based Panel Production system sewage according to claim 1 and 2, it is characterized in that: the thermal source of contaminated water evaporator adopts external steam or high-temperature flue gas, perhaps adopts combustion gas, fire coal, biomass-burning as thermal source.