A kind of method for preparing rubber powder with junked tire
The present invention relates to a kind of method for preparing rubber powder, particularly relate to a kind of method for preparing rubber powder with junked tire.
According to statistics, the discarded amount of whole world old tire has about 1,000,000 tons every year, only China just has 880,000 tons, like this a large amount of junked tires many vacant lots that not only account for, and become bacterium and carry the breeding ground of the insect of germ, with they recyclings, remain an insoluble problem so far well.
These junked tires are turned waste into wealth, and the most effectively and one of the method for tool economic benefit, are the rubber powders that they is processed into certain particle size.Varigrained rubber powder has different purposes, can mix sizing material instead of part rubber, is used to consume the doughnut tyre surface of glue amount maximum; Can be mixed for high-quality highway structure and house watertight composition with pitch; Can be used as the additive of modified plastics; Can make offset plate, blob of viscose is used for anti-skidding pavement, city, interior decoration etc., and in its production process, do not have " three wastes " and pollute, thereby utilize junked tire to prepare rubber powder to be subjected to various countries and generally to pay attention to.
Because rubber is elastomeric material, viscosity is big, is difficult to be processed into powdery under the normal temperature, so people attempt to adopt junked tire is carried out freezing processing earlier, and then pulverizes the technology that is processed into rubber powder.
Abroad, generally adopt comparatively ripe liquid nitrogen frozen disintegrating process, because external liquid nitrogen is cheap, and government reclaims junked tire for encouraging, and also gives the certain economic subsidy.Owing to liquid nitrogen is by air liquefaction and separates and get, adopt the air compression and the cooling of expanding of backheat principle on the technology, the vitrified temperature of rubber is about-80 ℃, and the gasification temperature of liquid nitrogen under normal pressure is-196 ℃, the temperature difference therebetween is 116 ℃, as everyone knows, gas separates and refrigeration cool-down is irreversible on thermodynamics, cryogenic temperature is low more, and irreversibility is big more, and energy consumption is just big more, therefore adopt liquid nitrogen frozen to pulverize processing technology, prepare rubber powder with junked tire, energy consumption is too high, is not suitable for China's national situation.
Application number be 96118817.0 (in please day be on July 17th, 1996, open day is on April 9th, 1997) application for a patent for invention the method for the meticulous pulverizing of a kind of air refrigeration low-temp is disclosed, this method is a kind of with at first low temperature precooling of material, the method of pulverizing again afterwards, in embodiment, obtaining of low-temperature receiver is employing is freezed pressure-air earlier in freon refrigerator after, divide two parts, a part directly enters the one-level turbine, adiabatic expansion in turbine, the Cryogenic air that obtains enters air-air recuperative heat exchanger (hereinafter to be referred as heat exchanger) cooling another part pressure-air, this strand pressure-air enters the secondary turbo-expander again, adiabatic expansion further obtains the lower level low cold air as low-temperature receiver once more, and the Cryogenic air of low-temperature receiver is sent in the Lowtemperaturepulverizer;
In addition, in this method, pulverized material is at first pre-cooled, the low-temperature receiver cold air heat exchange that enters material cooling heat exchanger and adverse current and come, and be chilled to below the vitrification point, send into again in the Lowtemperaturepulverizer, pulverize, owing to be connected with low-temperature receiver cold air all the time in the pulverizer, the product needed backheat of pulverizer outlet is handled.
This method needs the adiabatic expansion of heat exchanger and process secondary turbo-expander owing to obtaining of low-temperature receiver, so the equipment that needs is many, investment is big, and complex process, energy consumption is also high, also, enter heat exchanger and adverse current afterwards and next low-temperature receiver cold air heat exchange, and be reduced to below the vitrification point because its material is pre-cooled, entering pulverizer afterwards converges with the low-temperature receiver cold air that feeds in the pulverizer again, its crushing process carries out all the time at low temperatures, there is no need really, and wastes a large amount of energy consumptions.
It is many to the objective of the invention is to overcome the method equipment needed thereby that provides in the above-mentioned patent application, investment is big, complex process, many defectives that energy consumption is high, and provide a kind of method for preparing rubber powder with junked tire, obtaining of low-temperature receiver need not heat exchanger and secondary turbo-expander in this method, but adopt freon refrigerator multistage refrigeration, a turbo-expander adiabatic expansion refrigeration, the exhaust of turbo-expander directly enters Leng Ta, rather than enters pulverizer, in cold tower, cool off material with the material reverse heat-exchange, therefore the product of pulverizer outlet is a normal temperature, saves cold consumption greatly, and product does not need backheat to handle, so method technology provided by the invention is simple, equipment needed thereby is few, invests for a short time, and can save energy consumption greatly.
Embodiment of the present invention is as follows:
Provided by the inventionly prepare the method for rubber powder, be characterised in that to comprise following concrete steps with junked tire:
Under the normal temperature at first with junked tire through cleaning, dry and to be broken into granularity be 8-40 purpose micelle, remove wherein steel wire and fiber, send in the moving fluid bed cold tower;
2. obtaining of low-temperature receiver: adopt general cold-peace air turbine swell refrigeration to obtain low-temperature receiver, the pressure-air that is about to clean dry obtains-60 ℃ through freon refrigeration unit multistage refrigeration--80 ℃ of cold airs, this cold air enters an air turbine machine again and carries out adiabatic expansion, promptly obtains-110 ℃--130 ℃ low-temperature receiver cold air;
3. the cold air of low-temperature receiver is fed cold tower by the bottom of cold tower, in cold tower,, and is chilled to below the vitrification point, send into pulverizer again with top-down reverse converging of junked tire micelle, in pulverizer by meticulous be ground into Powdered.
4. subsequent treatment: the powdery product to the pulverizer outlet sieves, and divides the varigrained rubber powder of hanking as different purposes.
Selected pulverizer can be centrifugal impact grinder in this method, or is hammer crusher, or is high speed toothed disk mill impact shear formula pulverizer, and best with high speed toothed disk mill impact shear formula pulverizer effect.
The method for preparing rubber powder with junked tire provided by the invention, because obtaining of low-temperature receiver need not heat exchanger and secondary turbo-expander, but the pressure-air of clean dry is adopted freon unit multistage refrigeration, a turbo-expander adiabatic expansion, its exhaust directly enters top-down reverse converging of junked tire micelle in cold tower bottom (rather than entering pulverizer) and the cold tower and is chilled to below the vitrification point, and in pulverizer, pulverize, the product of pulverizer outlet is a normal temperature, do not need backheat to handle, so method technology provided by the invention is simple, required equipment is few, therefore investment is also few, production cost is also low, adding does not need to provide the low-temperature receiver cold air in pulverizer, its product does not need backheat to handle, and material enters Leng Taqian does not need precooling yet, generally speaking, the junked tire of handling identical tonnage can be saved 50% energy consumption.
Below in conjunction with embodiment the present invention is further described: under the normal temperature, at first junked tire is cleaned, dedusting after the preliminary treatment such as drying, is broken into the thick micelle of 8-40 purpose, sends into afterwards in the moving fluid bed cold tower;
Air in the ambient air is removed by filter wherein mechanical particle and dust through filter, send into compressor afterwards, adiabatic compression is to 0.8Mpa, temperature is reduced to 30 ℃-40 ℃ in aftercooler, moisture that condensation is got off and oil content are separated then, be further purified drying again, become dry dustless compressed air.In the flow process, purifier apparatus is extremely important, the air dew point temperature must be brought down below-70 ℃, not being frozen into bulk to guarantee that heat exchanger does not stop up with freezing micelle. pure pressure-air freezes via freon refrigeration unit multistage, make the pressure-air temperature reduce to-60 ℃--80 ℃, enter a turbine afterwards and carry out adiabatic expansion, promptly obtain-110 ℃--130 ℃ low-temperature receiver cold air;
The low-temperature receiver cold air is fed top-down reverse converging of junked tire micelle in cold tower and the cold tower by the bottom of moving fluid bed cold tower, and the junked tire micelle is refrigerated to below the vitrification point, send into afterwards carry out in the pulverizer meticulous be ground into Powdered; Pulverizer can be centrifugal impact grinder, can be hammer crusher, also can be high speed toothed disk mill impact shear formula pulverizer, and best with high speed toothed disk mill impact shear formula pulverizer effect.
Subsequent treatment: the product of pulverizer outlet is sieved through screening machine, and carry out packing by different grain size.Thicker micelle can be used as fine particle regenerated rubber or floatingization rubber powder or other purposes, pulverizes again but can not get back in the pulverizer, and be very difficult pulverized once more because be frozen the 40-60 purpose rubber powder of pulverizing.