Arrangement for classifying particles in a pyrolysed char

An identification and separation arrangement for forming various mixtures of agglomerates from pyrolized reclaimed carbonaceous materials. The identification and separation arrangement uses a dry air source (28) and a source (16) of reclaimed carbonaceous materials containing small agglomerates and large agglomerates. The reclaimed carbonaceous materials are mixed with the dry air source, pressurized and then introduced to a pulverizer mill (12). The pulverizer mill (12) performs a first round of identification and separation by dividing the reclaimed carbonaceous material into small agglomerates and large agglomerates. The pulverizer mill (12) further fractionates the large agglomerates to form more small agglomerates. The small agglomerates are then moved to a classifier (14) that performs a second round of identification and separation. The classifier (14) separates the small agglomerates into coarse agglomerates and fine agglomerates.

FIELD OF THE INVENTION

The present invention relates to an arrangement for identifying and separating a mixture of carbon black or other carbonaceous materials into different qualities.

BACKGROUND OF THE INVENTION

There have been many attempts to recycle tires and other rubber products to reclaim usable hydrocarbons through the use of a process called pyrolysis. Through pyrolysis, tires have been processed to produce fuel and other hydrocarbon compounds. One particular byproduct resulting from the pyrolysis process is an ash or char material which is leftover after the process is complete. Attempts have been made to use this char as a low grade carbon black for use as a type of filler. However, this has been met with several disadvantages, most significantly the disadvantage of the impurities in the char resulting from the random distribution of particle size of the char itself. It has been found that a composition of raw char has large particles or large agglomerates, and small particles or small agglomerates. However, some applications for using carbon black as a filler compound require that the carbon black mixture consists of primarily small agglomerates which create a “fluffy” carbon black mixture suitable for use as a filler for rubber in plastics.

There have been attempts to create “fluffy” carbon black by using grinders that crush the mixture of reclaimed carbonaceous materials into small particles or agglomerates. However, these attempts have not always produced a mixture with consistent agglomerate size and such mixtures often have an unfavorable nitrogen surface area of the agglomerate particles. Thus, there exists a need to fractionate samples carbon black containing agglomerates into mixtures having consistent particle size and different grades or classifications based on particle size and other factors.

Accordingly there exists a need to improve the identification and separation of carbon black containing agglomerates into mixtures having smaller more consistent agglomerate sizes and better physical properties such as a high nitrogen surface area value.

SUMMARY OF THE INVENTION

The present invention relates to an identification and separation arrangement for forming various qualities of agglomerate mixtures from pyrolized polymeric materials. The pyrolized reclaimed carbonaceous materials are derived from used tires, automotive shredder residue and virtually any type of used polymer. After the step of pyrolysis has occurred the identification and separation arrangement is used. The identification and separation arrangement uses a dry air source and a source of reclaimed carbonaceous materials containing small agglomerates and large agglomerates. The reclaimed carbonaceous materials are mixed with the dry air source, pressurized and then introduced to a pulverizer mill. The pulverizer mill performs a first round of identification and separation by dividing the reclaimed carbonaceous material into small agglomerates and large agglomerates. The pulverizer mill further fractionates the large agglomerates to form more small agglomerates. The small agglomerates are then moved to a classifier that performs a second round of identification and separation. The classifier separates the small agglomerates into coarse agglomerates and fine agglomerates.

The reclaimed carbonaceous material discussed below is a mixture of elements including carbon black and inorganic functional fillers that have clustered together for form agglomerates of various sizes. The present invention seeks to separate the reclaimed carbonaceous materials into different classes of filler material having different particle sizes and surface chemistries. The present invention also achieves the goal of fractionating large agglomerates into smaller agglomerates that are more useful filler materials.

The large agglomerates discussed below include clusters of agglomerates that are between about 1 micron and about 100 microns in size, while the small agglomerates exiting the pulverizer mill are agglomerates between generally about 1 micron and about 45 microns in size. The coarse agglomerates mixture that are obtained from the classifier have agglomerates that are generally about 10 microns to about 20 microns in size, have a greater density, and are suitable to use as filler materials where a lower grade of carbon black can be used. The fine agglomerates mixture are a filler material having agglomerates of low density and are generally about 10 nm to about 35 nm in size. These fine agglomerates are suitable fillers where high grade carbon black particles are needed that are equivalent to virgin carbon black fillers.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1depicts a schematic view of the identification and separation arrangement10in accordance with the present invention. Referring now to all of the figures andFIG. 1in particular, the arrangement10includes a pulverizer mill12and a classifier14. A hopper16serves as a source for the reclaimed carbonaceous materials to the arrangement10. The hopper16is used to collect reclaimed carbonaceous materials prepared from the pyrolysis of recycled polymeric materials, such as but not limited to scrap tires, polymeric automotive components, used rubber materials, and plastic containers or the like. The reclaimed carbonaceous materials consist of large agglomerates, and small agglomerates of carbon black and other materials. While a collection hopper16is used to hold the reclaimed carbonaceous materials it is possible for the reclaimed carbonaceous materials to be fed directly into the arrangement10from a pyrolysis reactor (not shown) without first being collected in the hopper16.

A valve18controls the flow of reclaimed carbonaceous materials from the hopper16to a magnet separator20. The reclaimed carbonaceous materials sometimes have metal particles that were present in the recycled polymeric material prior to pyrolysis. These metal particles can harm the pulverizer mill12and the magnet separator20removes these unwanted metal particles. The use of the magnet separator20is not required and a greater or lesser number of magnet separators can be used.

After passing through the magnet separator20the reclaimed carbonaceous material is presented to a screw22that rotates and controls the flow of the material to the pulverizer mill12. A valve24is used to turn on and off the flow of reclaimed carbonaceous material to a mixing node26. At the mixing node26the reclaimed carbonaceous material is mixed with dry, filtered high pressure air generated from an air source28. Together the mixture of dry pressurized air and reclaimed carbonaceous material are a feed that is introduced through a feed inlet30(seeFIG. 2) of the pulverizer mill12.

FIG. 2. depicts a schematic diagram of the pulverizer mill12which has a vortex column28where pressurized feed is introduced through the feed inlet30and swirls around the vortex column28causing the small agglomerates present in the feed to move to the top of the vortex column28while the larger agglomerates fall downward. While a single feed inlet30is described it is possible to have a greater number of feed inlets to adjust or enhance the swirling in the vortex column28. A classifying disk32is present in the vortex column28and contributes to the swirling of the feed and prevents large agglomerates from moving past the classifying disk22. The classifying disk32swirls the agglomerates and air in the vortex column28and uses specific gravity to separate the heavy dense agglomerates and particles from the lighter less dense agglomerates and particles. Thus the heavy dense agglomerates settle to the bottom of the vortex column28, while the less dense agglomerates move to the top of the vortex column28.

As the larger agglomerates move to the bottom of the vortex, they enter a fractionation chamber34of the pulverizer mill12. At least two opposing air inlets36are present in the fractionation chamber34for blowing the large agglomerate particles at opposite sides of the chamber toward each other. While two opposing air inlets36are discussed it is possible to have a greater or lesser number of opposing air inlets36. The large agglomerate particles are accelerated toward each other, collide and are fractionated into smaller agglomerates. The smaller agglomerates are reintroduced into the vortex column28where they go past the classification disk32if their density is low enough, and then travel out of a small agglomerates port38. The larger agglomerates that do not get fractionated exit a chamber outlet38and are collected. Optionally the large agglomerates that leave via the chamber outlet38can be reintroduced to the reclaimed carbonaceous material at the valve24.

The small agglomerates that pass through the small agglomerates port38flow on to one of two filter hoppers40,40′. The filter hoppers contain a polymer surface area filter that collects the small agglomerates which have a tendency to become airborne after leaving the vortex column28. The present invention describes using two filter hoppers for collecting the small agglomerates, however, it is within the scope of this invention for a greater or lesser number of filter hoppers to be used depending upon the rate of production from the pulverizer mill12. Valves42,42′ control the flow of small agglomerates from the filter hoppers40,40′ onto a small agglomerate supply hopper44that is used to supply small agglomerates to the classifier14. WhileFIG. 1depicts multiple valves42,42′ associated the filter hoppers40,40′ it is possible to have a greater or lesser number of valves. After leaving the small agglomerate supply hopper44the small agglomerates are optionally passed through a second magnet filter46to further remove any metallic impurities present. A feed screw48receives the small agglomerates and controls the flow of small agglomerates supplied to a conveyor50that moves the small agglomerates to another feed screw52and valve54that control the flow of the small agglomerates to the classifier14. It is with the scope of this invention to have the feed screw48flow directly to the classifier14, however, it is preferable to use multiple feed screws and the conveyor because of the physical size of the components in the identification and separation arrangement10requires moving the small agglomerates a distance between components.

Referring now toFIGS. 1 and 3the small agglomerates enter the classifier14through the one of two high pressure inlets66. The small agglomerates are mixed with dry pressurized air, fed through one of the two inlets66and are swirled in a vortex column56of the classifier14where the small agglomerates are separated into a coarse agglomerates mixture and a fine agglomerates mixture. Some of the small agglomerates are made of coarse agglomerates with fine agglomerates stuck to the coarse agglomerates. The swirling of the small agglomerates causes the fine agglomerates which have a low density and are sized in the nanometer range to separate from the coarse agglomerate particles which are much denser and are measured in microns. The swirling action in the vortex column56is caused by the air pressure flowing through the high pressure inlets66and a rotary classification wheel58which causes the fine agglomerates which are less dense and have a smaller particle size to move to the top of the vortex column56. The coarse agglomerates which are denser and generally larger in size than the small agglomerates move to the bottom of the vortex column. It is within the scope of this invention to have a greater or lesser number of air inlets66as well as having the small agglomerates enter the vortex column56through more than one of the high pressure inlets66.

The rotary classification wheel58functions in the same way as the classification disk32of the pulverizer mill12by only allowing agglomerates of a certain size and density to pass out of the vortex column58through a fine agglomerates outlet64. The coarse agglomerates settle to the bottom of the vortex column56and are collected in a container62for use as a filler in processes where coarse agglomerates are acceptable. The fine agglomerates that pass through the fine agglomerates outlet64flow to a filter hopper68containing a polymeric surface area filter that collects the fine agglomerates. This step is necessary because the fine agglomerates are so small in size that they become easily airborne. After passing through the filter hopper68the fine agglomerates are then optionally passed through a magnet separator70to remove any metallic impurities that might be present and then the fine agglomerates are moved to a holding area72where they form a fine agglomerates mixture that is stored in a container, pelletizer, bag or blended with an elastomer to prevent the fine agglomerates from becoming airborne. The fine agglomerates mixture and coarse agglomerates mixture contain high amounts of carbon black and are useful filler materials that are comparable to virgin carbon blacks.

Additional information and examples of the materials used in accordance with the present invention can be found in the following applications: U.S. patent application No. 60/998,197 entitled “Elastomer Composition with Reclaimed Filler Material,” Filed Oct. 9, 2007, application No. 60/986,318 entitled “Process For Classifying Particles In A Pyrolysed Char,” filed Nov. 8, 2007, application No. 60/986,369 entitled “Asphalt Composition Using Pyrolysed Carbonaceous Materials,” filed Nov. 8, 2007, and application No. 60/986,126 entitled “Enhanced Fine Agglomerate Mixture,” filed Nov. 7, 2007, wherein the entirety of each application is hereby incorporated by reference.