Patent Description:
Paramagnetic substances can be magnetized under an external magnetic field. Paramagnetic materials include, for example, manganese, chromium, cerium, iron, cobalt, potassium, vanadium, and their oxides or sulfides. Without influence of the external magnetic field, the magnetic dipole in a paramagnetic molecule points in random directions, so it has zero magnetism. As a suitable external magnetic field is applied, a paramagnetic substance is magnetized since the number of magnetic dipoles aligned parallel toward the direction of the magnetic field is more than those aligned away from the field.

Conventional magnetic filters remove paramagnetic substances or particles from gas or liquid fluids through the influence of an external magnetic field generated by permanent magnetic or electromagnetic sources. For example, magnetic filters disclosed in <CIT>, <CIT>, and <CIT> and <CIT>, can remove paramagnetic particles from liquid streams in refinery and chemical facilities. The paramagnetic particles which include FeS, FeO, Fe(OH)<NUM>, Fe(CN)<NUM>, etc. are formed when carbon steel, which is a common material in plant construction, corrodes in the presence of acidic contaminants in the process stream to yield ferrous ions, which react with sulfur, oxygen and water. These paramagnetic contaminants tend to adhere to magnets.

Diamagnetic substances contain pairs of magnetic dipoles which tend to cancel out the magnetism internally. Diamagnetic materials include, for example, carbon (diamond), carbon (graphite), silica, alumina, bismuth, phosphorous, mercury, zinc, lead, tin, copper, silver, gold, water, ethyl alcohol, etc. In the presence of an external magnetic field, the magnetic dipoles of diamagnetic substances align parallel and in reverse direction to the magnetic field and therefore exhibit no magnetism. Prior art magnetic filters, for example as disclosed in <CIT>, <CIT>, <CIT> and <CIT>, cannot remove diamagnetic substances.

Filtration with mesh screens and the like is the standard employed to separate diamagnetic particles from gas or liquid fluids but this technique is not efficient for small particles. For example, nano carbon particles such as particulate matter PM <NUM> emitted from power plants, steel mills, and mobile sources including cars and motorcycles cannot be effectively abated. Similarly, nano particles in the form of catalyst fines, steel rust, carbon residue or polymerized slurry found in refinery and chemical plants cannot be effectively filtered. Solid particles comprising FeS, FeO, sand, carbon residue, etc. of various sizes are also present in natural gas processes. Paramagnetic and diamagnetic materials are major constituents of both natural and industrial pollutants and contaminants.

A method of separating particles such as diamagnetic, non-magnetic and/or very weak paramagnetic particles from a liquid is disclosed in <CIT>. To achieve this separation the magnetic susceptibility of the liquid is modified by dissolving a paramagnetic substance in the liquid containing the diamagnetic particles, before passing it through a filter.

It is highly desirable to develop systems for removing both of paramagnetic and diamagnetic particles, or at least the diamagnetic particles, of all sizes from the gas and liquid fluids.

The present invention is based in part on the demonstration that common diamagnetic solid substances can be magnetized under an external magnetic field through coordinated interaction of the diamagnetic solid substances with an inducing or inducement paramagnetic material (IPM). The IPM which is solid should preferably not be in direct contact with the magnet which generates the external magnetic field. On the other hand, the diamagnetic solid substance preferably is in direct contact with the IPM or is uniformly mixed with the IPM. The position and distance of a magnetic source, such a magnetic bar or electromagnet, to the solid mixture of diamagnetic and IPM are adjusted and maintained so as induce sufficiently strong magnetism in the diamagnetic solids which causes the diamagnetic solids to be attracted by the magnetic field as well. In this fashion, both diamagnetic and paramagnetic substances can be removed from a liquid or gaseous stream in which the solid mixture is entrained or fluidized. Not all paramagnetic substances can induce magnetism in diamagnetic solid substances in the presence of an external magnetic field in the magnetic filters of the present invention. Thus, "inducement paramagnetic material" or "IPM" refers to solid paramagnetic material that can cause diamagnetic solid materials to exhibit sufficient magnetism to be attracted by a magnetic field and be removed or captured with the magnetic filter of the present invention.

Accordingly, in one aspect, the invention is directed to a method of removing diamagnetic material from a carrier stream as defined in claim <NUM>.

In another aspect, the invention is directed to a magnetic filter for separating diamagnetic contaminants from a carrier stream as defined in claim <NUM>.

The magnetic filter serves as a robust separation zone created by the presence of inducement paramagnetic material (IPM) and magnets that are shielded from the IPM by non-magnetic partitions. Preferably, elongated magnet assemblies are employed to generate a uniform magnetic field in the separation zone. The elongated magnet assemblies can be arranged in parallel or traverse to the fluid flow within the filter. The IPM in the void volume or space between the magnets afford a large surface area onto which diamagnetic and paramagnetic materials in the fluid steam can contact and be attracted to. While the invention will be described using permanent magnets to establish the magnetic field, it is understood that electromagnets can be employed.

<FIG> depicts the schematic configuration of a vertical filter <NUM> that comprises a housing <NUM> having an inlet pipe <NUM> that can be coupled to a contaminated process stream through control valve <NUM>, an outlet pipe <NUM> from which a treated process stream exits through control valve <NUM>. Housing <NUM> defines an interior region <NUM>. Flow through drain pipe <NUM>, which is welded to the bottom of housing <NUM>, is regulated with control valve <NUM> which is normally closed during filtration operations but which is opened during clean-up service to discharge flush fluid from housing <NUM>. The size of the opening in drain pipe <NUM> is sufficient to accommodate large particles that accumulate in the filtration process.

A cover plate <NUM> is fastened by bolts <NUM> to an annular flange <NUM> that is welded to the outer perimeter along the top opening in housing <NUM>. A polymer gasket or other suitable sealing means may be inserted between cover plate <NUM> and flange <NUM> to insure a tight seal during the operation cycle. A top supporting plate <NUM>, which is fastened to the top rim of wire cage <NUM> around the perimeter by bolts <NUM>, facilitates the removal of the entire core assembly from filter housing <NUM> during the clean-up cycle. Both the top supporting plate <NUM> and the top rim of wire cage <NUM> are placed on a supporting ring <NUM> which is permanently connected to filter housing <NUM>. The weight of the core assembly causes top supporting plate <NUM> and the top rim of wire cage <NUM> to press tightly against supporting ring <NUM> to prevent the open end of each holder sleeve <NUM> and, thus magnetic bar assemblies <NUM>, from coming in contact with the process fluid during the filtration process.

The core assembly includes multiple, vertically oriented removable permanent magnetic bar assemblies <NUM> with each being fitted into an elongated diamagnetic sleeve holder <NUM>, IPM packing elements or substances <NUM> which fill up the space in between the sleeve holders <NUM> as the magnetic inducing media for solid diamagnetic substances in the process stream. Wire cage <NUM>, as a holder of IPM packing <NUM>, is preferably made of coarse wire of diamagnetic substances, such as stainless steel, with mesh size slightly smaller than the size of IPM packing substance <NUM> to prevent their loss to the process flow.

Preferably the IPM packing elements <NUM> are in layered arrangement with the largest ones on top and the smallest ones at the bottom. This gradient packing matrix configuration enables the magnetic filter to capture diamagnetic and paramagnetic substances of different sizes without causing significant pressure drops and throughput reductions.

The IPM is formed of materials with high and positive mass susceptibility. Suitable IPM include, for example, Ce, CeO<NUM>, CsO<NUM>, Co, CoO, Ni, CuO, NiO, NiS, Fe, FeO, Fe<NUM>O<NUM>, FeS, Mn, Ni/γAl<NUM>O<NUM>, Cr<NUM>O<NUM>, Dy<NUM>O<NUM>, Gd<NUM>O<NUM>, Ti, V, V<NUM>O<NUM>, Pd, Pt, Rh, Rh<NUM>O<NUM>, KO<NUM>, and mixtures thereof with Co, CoO, Ni, Fe, FeO, Fe<NUM>O<NUM>, FeS, Ni/γAl<NUM>O<NUM>, Cr<NUM>O<NUM>, Dy<NUM>O<NUM>, and Gd<NUM>O<NUM> being particularly preferred. Preferred configurations of the IPM packing elements include but not limited to conventional random packing such as rings, saddles, chips, and wires, structure packings, and macro-pore catalyst supports, such as guard-bed materials used in a fixed-bed reactor.

It is critical to keep the distance between the adjacent vertically oriented magnetic bar assembles <NUM> sufficiently close so that the IPM substances, which are packed in the filter, can induce sufficient magnetism to attract the diamagnetic substances from the process stream. The distance, which is measured from exterior surfaces of adjacent sleeve holders <NUM>, is from <NUM> to <NUM> and preferably from <NUM> to <NUM>. The magnetic flux intensity within the interior region <NUM> in magnetic filter <NUM> should be from <NUM>,<NUM> to <NUM>,<NUM> GS, and preferably from <NUM>,<NUM> to <NUM>,<NUM> GS, and most preferably from <NUM>,<NUM> to <NUM>,<NUM> GS.

Each sleeve holder <NUM>, which is highly permeable to magnetic fields, has a sealed bottom and an open top end which is preferably welded at its perimeter to the fitted hole at the top supporting plate <NUM>. This prevents the open end of each holder sleeve <NUM> and the associated magnetic bar assembly <NUM> from coming into direct contact with the process fluid during filtration. Top supporting plate <NUM> bears the weight of the plurality of permanent magnetic bar assemblies <NUM> with their associated holder sleeves <NUM>, the IPM packing substances <NUM>, and wire cage <NUM>.

<FIG> depicts the top view showing the top supporting plate <NUM> with its fitted holes for the sleeve holder <NUM>, and the IPM packing substance <NUM> which fills up the space between the sleeve holders <NUM>. One of sleeve holders <NUM> has a permanent magnetic bar assembly inserted therein with casing <NUM> enclosing a magnet block <NUM>. Casing <NUM> is permeable to magnetic fields.

<FIG> depicts the vertical cross sectional view of a permanent magnetic bar assembly <NUM> that includes an elongated casing <NUM> that is preferably made of a diamagnetic metal such as stainless steel and defines a chamber that accommodates one or more encased magnet blocks <NUM>. Each magnetic bar assembly <NUM> has a pulling ring <NUM> for withdrawing it from sleeve holder <NUM>. A plurality of short magnet blocks or cylinders <NUM> are stacked one on top of another and arranged so that each of the two poles of one magnet block is juxtaposed to an opposite pole of an adjacent magnet block. In this staggered arrangement, the axis of each elongated magnet block <NUM> is perpendicular to the central axis along the length of assembly <NUM>.

<FIG> illustrates a permanent magnetic bar assembly <NUM> where two adjacent pairs of blocks <NUM>,<NUM> having like poles pointing in the same first direction form a magnet block unit or array that is stacked over another magnet block unit, consisting of blocks <NUM>,<NUM> having like poles pointing in a second direction, which is opposite the first direction. The assembly <NUM> has a succession of such block units with opposite pole configurations. As is apparent, each magnet block unit or array can comprise more than <NUM> magnet blocks or cylinders.

In use, each permanent magnetic bar assembly <NUM> or <NUM> is supported within a sleeve holder <NUM>. It has been observed that the magnetic flux density of these encased permanent magnets as measured by a Tesla meter was essentially the same with or without a 304SSL sleeve. That is, the presence of the diamagnetic barrier (sleeve holder) did not result in a significant decay of the magnetic flux density. In contrast, permanent magnetic bar assemblies consisting of a plurality of magnet blocks that are arranged in tandem as shown in <FIG> exhibited a significant decrease in magnetic flux density when a 304SSL sleeve was used.

It has also been observed that diamagnetic and paramagnetic particles are not attracted to the entire surface of the magnetic bar assembly as shown in <FIG> but rather such particles form bands around the exterior surfaces. To reveal the arrangement of the magnet blocks in the magnetic bar assembly, Magnetic Viewer Cards were placed in front of both of the magnetic bar assemblies shown in <FIG> and <FIG>. The Magnetic Viewer Card is a flexible film containing liquid magnetic power. <FIG> show images that are created through polar induction by the magnetic field of the magnets. The images of the magnetic poles in each assembly can be seen through the card, where the light areas represent the junctions where N and S poles meet and the locations are quantitatively measured.

To compare the performance of the preferred magnetic bar assembly of <FIG> to that of the magnetic bar assembly of <FIG>, the same mass of Fe<NUM>O<NUM> powder was placed on separate pieces of paper (<NUM> by <NUM>). Each assembly with its associated sleeve was slowly rotated in non-contact fashion over the powder at a distance of <NUM> to <NUM> until essentially all the powder was pick up by attraction. As shown in <FIG>, almost the entire sleeve surface of the preferred magnetic bar assembly (<FIG> and <FIG>) was covered with iron oxide powder. In contrast, as shown in <FIG>, the magnetic bar assembly of <FIG> and <FIG> was able to attract iron powder onto a limited surface area of the sleeve surface where like poles met. As is apparent, the effective area of attraction is larger with the preferred magnetic bar assembly where the longitudinal axis of each magnetic bar is perpendicular to the central axis or length of the magnetic bar assembly.

As shown in <FIG>, a process stream entering filter housing <NUM> via line <NUM> initially travels through wire cage <NUM> and contacts the IPM packing substances while under the influence of a suitable magnetic field generated by the permanent magnetic bar assemblies <NUM>. Solid paramagnetic particles in the process stream <NUM> will be attracted to sleeve holders <NUM> and to the IPM packing substances <NUM>. Diamagnetic solids in the process stream <NUM> having magnetism induced by the IPM packing substances are also attracted to sleeve holder <NUM> and to IPM packing substances <NUM>. Treated process stream passes through wire cage <NUM> and exits filter housing <NUM> through control valve <NUM> and line <NUM>.

In the clean-up cycle, control valves <NUM> and <NUM> are closed in sequence. Cover plate <NUM> is opened and the entire core assembly, including permanent magnetic bar assemblies <NUM>, top supporting plate <NUM> along with sleeve holders <NUM>, wire cage <NUM> containing IPM packing substances <NUM>, is withdrawn from filter housing <NUM>. Thereafter, permanent magnetic bar assemblies <NUM> are withdrawn from the sleeve holders <NUM> to remove the magnetic field from the interior <NUM> thereby releasing the attracted solids of paramagnetic and diamagnetic substances from the outer surface of sleeve holders <NUM> and surfaces of the IPM packing. The core assembly is washed with water or other suitable fluid before the magnetic bar assemblies <NUM> are reinserted into sleeve holders <NUM>. The cleaned core assembly is then re-positioned into filter housing <NUM> and the top opening is closed and sealed with cover plate <NUM> and the fitted gasket. Before starting the operation cycle, control valves <NUM> and <NUM> are opened to briefly introduce high pressure fluid, such as water, process stream or air from line <NUM> to flush out the residual solids in filter housing <NUM>, and to remove the flushed solids through control valve <NUM> and drain line <NUM>. Finally, control valves <NUM> and <NUM> are closed and control valves <NUM> and <NUM> are opened to start the operation cycle again.

<FIG> depicts a horizontal filter <NUM> that comprises a housing <NUM> having an inlet pipe <NUM> that can be coupled to a contaminated process stream through control valve <NUM>, an outlet pipe <NUM> from which a treated process stream exits through control valve <NUM>. Housing <NUM> defines an interior region <NUM>. Flow through drain pipe <NUM>, which is welded to the bottom of housing <NUM>, is regulated with control valve <NUM> which is normally closed during filtration operation and, is opened during clean-up service to discharge flush fluid from housing <NUM>.

The left cover plate <NUM> is fastened, by bolts <NUM> to an annular flange <NUM> that is welded to the outer perimeter along left side opening of housing <NUM>, while the right cover plate <NUM> is fastened, by bolts <NUM> to an annular flange <NUM> that is welded to the outer perimeter along right side opening of housing <NUM>. A polymer gasket may be inserted between cover plates and flanges.

The filter assembly includes horizontal multiple permanent magnetic bar assemblies <NUM> that are removable from filter housing <NUM>. Each bar assembly <NUM> fits into an elongated diamagnetic sleeve holder <NUM>, which is constructed of a diamagnetic metal such as stainless steel 304SSL. Each of the sleeve holders <NUM> is sealed at one end and the open end is preferably welded to the fitted hole in cover plate <NUM> to form integral units therewith. To secure the position and support the weight of sleeve holders <NUM> and the magnetic bar assembly <NUM>, each sleeve holder is fitted into a hole of the partition plate <NUM> which is welded to housing <NUM> to divide filter interior into two equal chambers. To induce the magnetism to solid diamagnetic substances in the process stream, wire cages <NUM> is filled with IPM packing substances <NUM> which are inserted into the space between the sleeve holders <NUM> from both sides of the filter openings. Wire cage <NUM>, as a holder of IPM packing substances <NUM>, is preferably made of coarse wire of diamagnetic substances with mesh size slightly smaller than the size of IPM packing substances <NUM> to prevent their loss to the process flow.

Preferred IPM packing substances and configurations are the same as those used in the vertically oriented magnetic filter <NUM> shown in <FIG>. The spacing between the exterior surfaces of adjacent sleeves <NUM> holding horizontally oriented magnetic bar assemblies <NUM> is in the range from <NUM> to <NUM>, and preferably from <NUM> to <NUM>. The magnetic flux intensity in the filter should be <NUM>,<NUM> to <NUM>,<NUM> GS, preferably <NUM>,<NUM> to <NUM>,<NUM> GS, and more preferably <NUM>,<NUM> to <NUM>,<NUM> GS.

As depicted in <FIG>, casing <NUM> of each permanent magnetic bar assembly <NUM> is a diamagnetic metal such as stainless steel <NUM> SSL and defines a chamber that accommodates one or more magnet blocks to form a permanent magnetic bar assembly <NUM>. Each permanent magnetic bar assembly <NUM> has a pulling ring <NUM> on top for withdrawing from sleeve holder <NUM> during clean-up cycle. A plurality of short magnet blocks <NUM> are stacked one on top of another and arranged so that each of the two poles of one magnet block is juxtaposed to an opposite pole of an adjacent magnet block.

<FIG> depicts the cross sectional lateral side view showing the fitted holes for the sleeve holder <NUM>, and the IPM packing substance <NUM> which fills up the space between the sleeve holders.

The configuration of the magnetic filter <NUM> directs the process stream entering filter housing <NUM> via line <NUM> to flow downward in left chamber toward the bottom opening between partition plate <NUM> and filter housing <NUM>. The process stream then flows upward in right chamber toward the exit and treated process stream exits filter housing <NUM> through control valve <NUM> and line <NUM>. In both chambers of the filter, the process stream travels through the outer surfaces of sleeve holders <NUM>, and the wire cage <NUM> contacting the IPM packing substances <NUM> under influence of a strong magnetic field generated by the permanent magnetic bar assemblies <NUM>. Solid paramagnetic substances in the process stream <NUM> will be attracted to the outer surfaces of sleeve holders <NUM>, and to the surfaces of IPM packing substances <NUM>. Diamagnetic solids in the process stream <NUM> having magnetism induced by the IPM packing substances will be attracted to outer surfaces of sleeve holders <NUM> and to the surfaces of IPM packing substances <NUM>.

In the clean-up cycle, permanent magnetic bar assemblies <NUM> are withdrawn from the sleeve holders <NUM> from the filter to remove the magnetic field from interior space <NUM> of the filter, releasing the attracted solids of paramagnetic and diamagnetic substances from the outer surfaces of sleeve holders <NUM> and surfaces of the IPM packing <NUM>. After control valves <NUM> and <NUM> are closed, control valves <NUM> and <NUM> are opened to introduce high pressure fluid via line <NUM>, such as water, process stream or air to flush out the released solids through control valve <NUM> and drain line <NUM>. To start the operation cycle, magnetic bar assemblies <NUM> are replaced into sleeve holders <NUM>, control valves <NUM> and <NUM> are closed and control valves <NUM> and <NUM> are opened in sequence.

The magnetic filters of the present invention are particularly suited for abatement programs to remove airborne contaminants especially particles that are <NUM> to <NUM> in size, such as particulate matter PM <NUM>. Both diamagnetic and paramagnetic particles can be removed from the streams. For example, filters can be installed in clean room operations or in airplanes to clean recirculated air, in electric power plant or steel mill to clean up flue gas, or in mobile emission sources, such as cars to reduce air pollution. The magnetic filters can also be employed to remove diamagnetic particles in liquid streams in refineries, chemical plants and other facilities in continuous operations where particles in process streams can accumulate and damage equipment. For instance, inorganic catalysts, that become free flowing or otherwise detached from a catalyst bed, can be effectively removed from streams with the inventive magnetic filter. Furthermore, this filter can be installed in ultra-pure water production facility to remove the ultra-fine diamagnetic and paramagnetic particles from the product stream. Similarly, a filter can be positioned upsteam of a natural gas treatment plant to remove ultra-fine diamagnetic particles, such as sand, carbon residual, and diamagnetic metal oxides, and ultra-fine paramagnetic particles, such iron sulfide, iron oxides, etc., from a natural gas stream at the gas field in order to protect plant equipment and improve plant efficiency.

The following examples are presented to further illustrate different aspects and embodiments of the invention and are not to be considered as limiting the scope of the invention. To demonstrate the interaction between paramagnetic and diamagnetic substances under the influence of an external magnetic field generated by permanent magnets, paramagnetic and diamagnetic powders were selected for various experiments. The substances are classified into paramagnetic and diamagnetic based on their mass susceptibilities (MS).

Mass susceptibility is the magnetic susceptibility of a substance per gram and magnetic susceptibility is the magnetization of a material per unit applied field. It describes the magnetic response of a substance to an applied magnetic field. All substances are characterized by mass susceptibility (MS) values. Paramagnetic substances have higher and positive MS values whereas diamagnetic substances have lower or negative MS values. Table <NUM> lists the MS values of selected substances.

The degree or strength of magnetism exhibited by selected solid substances with high MS values in a magnetic field was measured. A permanent magnetic bar assembly with a magnetic strength of <NUM>,<NUM> GS was employed. The selected solid powders were: cobalt (Co), iron (Fe), nickel (Ni), nickel oxide (NiO), iron oxides (FeO and Fe<NUM>O<NUM>), iron sulfate (FeSO<NUM>), iron chloride (FeCl<NUM>), Ni supported on γ-alumina catalyst (Ni/γAl<NUM>O<NUM>), dysprosium oxide (Dy<NUM>O<NUM>), gadolinium oxide (Gd<NUM>O<NUM>), and chromium oxide (Cr<NUM>O<NUM>).

For each test, approximately <NUM> grams of powder were weighed by a precision balance (to <NUM>-<NUM> grams) and placed into a (precision weighed) glass vessel. The permanent magnetic bar assembly was then placed near the powder. After attracting of the power, the magnetic bar was removed and the vessel with residual powders (if any) was weighed. Weight percent (%) of the powders attracted by magnetic bar was calculated.

As shown in the data set forth in Table <NUM>, metals and their oxides with MS values of approximately <NUM> to <NUM>,<NUM> × <NUM>-<NUM> c. unit are readily attracted by the permanent magnetic bar assembly, except for NiO (no attraction) and Cr<NUM>O<NUM> (only <NUM> %). As expected, Dy<NUM>O<NUM> and Gd<NUM>O<NUM> with their very high susceptibilities showed complete attraction. Surprisingly, however, even with very high MS values (over +<NUM>,<NUM> × <NUM>-<NUM>), iron sulfate (FeSO<NUM>) and iron chloride (FeCl<NUM>) showed no magnetism and were not attracted by the MB. This experiment suggests that mass susceptibility serves only a guideline for selecting suitable inducement paramagnetic materials. Metals or metal oxides are possible candidates as suitable inducing paramagnetic substances while metal salts such as FeSO<NUM> or FeCl<NUM> are excluded from the consideration, despite of their high MS values.

This experiment confirmed that diamagnetic substances by themselves are not attracted to a magnetic bar. The diamagnetic substances tested were silicon, silicon carbide (SiC), γ-alumina (γAl<NUM>O<NUM>), non-magnetic butadiene, titanium oxide (TiO<NUM>), ceramic, activated carbon, polyethylene, and elemental sulfur. Magnetic butadiene was also tested. A permanent magnetic bar assembly with a magnetic strength of <NUM>,<NUM> GS was positioned next to powder samples; none of the powders was attracted onto the magnetic bar, except the magnetic butadiene (containing paramagnetic substance). The presence of the magnetic field did not induce magnetism in the diamagnetic materials.

Simply coating a permanent magnetic bar assembly with a paramagnetic substance does not render the assembly attractive to diamagnetic materials. In this example, the permanent magnetic bar assembly coated with iron oxide (FeO) powder was positioned each of various diamagnetic powders that included Si, SiC, SiO<NUM>, Al<NUM>O<NUM>, non-magnetic butadiene, magnetic butadiene, TiO<NUM>, ceramics, activated carbon, and polyethylene. None of the diamagnetic powders was attracted by permanent magnetic bar assembly, except for the magnetic butadiene which contained a paramagnetic substance.

In mixing a diamagnetic substance with a suitable IPM substance, the paramagnetic substance acts as a magnetic inducing agent. The diamagnetic substance in the mixture exhibits magnetism when the mixture is exposed to a magnetic field that is created by a permanent magnetic bar or electromagnetic. Both the paramagnetic and diamagnetic substances in the mixture are attracted to the magnet.

Experiments were performed in air (gas phase) at ambient conditions. For each test, approximately <NUM> gram of diamagnetic powders and <NUM> grams of paramagnetic powders were weighed by a precision balance (to <NUM>-<NUM> grams) and the mixture was placed into a precision weighed glass vessel. A permanent magnetic bar assembly with magnetic power of <NUM>,000GS was position adjacent the mixture to attract powders from the vessel. The magnet was removed and the vessel with residual mixed powders was weighed. The weight percent (%) of the mixed powders attracted by the magnet; the data is summarized in Tables <NUM> and <NUM>.

As set forth in Table <NUM>, with Ni /γAl<NUM>O<NUM> as the inducing agent, the magnetic bar showed only mild attractions for γ Al<NUM>O<NUM>, SiC, resid fluid cracking catalyst (RFCC-Al<NUM>O<NUM>/SiO<NUM>: <NUM>/<NUM>), elemental sulfur (S), and activated carbon, but exhibited a significantly higher attraction for silicon.

As set forth in table <NUM>, FeO is a better inducing agent than Ni /γAl<NUM>O<NUM> since the magnetic bar attracted a much higher percentage of the paramagnetic and diamagnetic mixtures.

This experiment is similar to that of Example <NUM> except that an IPM in the form of thin carbon steel wires (CSW) was used instead of iron powder. As shown in Table <NUM>, <NUM> to nearly <NUM>% of the diamagnetic substance were attracted by the magnet, except in the case the elemental sulfur.

Liquid phase testing was conducted at ambient conditions. Specifically, for each test, approximately <NUM> grams of water were mixed with <NUM> gram diamagnetic powder in a precision weighed vessel. Thereafter, paramagnetic powder was added into the mixture. A permanent magnetic bar assembly, with a magnetic power of <NUM>,<NUM> GS, was inserted into the liquid mixture, allowing the suspended solid powders to be attracted by the magnet. The magnet was removed and solid powders scrapped off and the cleaned magnet was reinserted into the solvent and allowed to attract additional powder. After removing the magnet the second time, the vessel with the solution containing the residual powders was weighed. The weight percent (%) of the mixed powders attracted by magnet was calculated.

Table <NUM> are the results for testing using water as the solvent, RFCC powder (equilibrium resid fluid cracking catalyst (SiO<NUM>/Al<NUM>O<NUM>: <NUM>/<NUM>) as the diamagnetic material (DM), and Fe<NUM>O<NUM> as the IPM. Approximately <NUM>, <NUM>, <NUM>, and <NUM> grams of Fe<NUM>O<NUM> were added in each instance and the results show that <NUM> to nearly <NUM> % of the mixed powders was attracted by the magnet, depending upon the amount of Fe<NUM>O<NUM> added and the position of the magnet (related to magnetic strength). The amount of powder attracted was proportional to the amount of Fe<NUM>O<NUM> added to the mixture.

This experiment was similar to that of Example <NUM> except diesel was the solvent. The results as set forth in Table <NUM> demonstrate that approximately <NUM> to <NUM>% of the mixed solid powders was attracted by the magnet with the amount of powder in diesel attracted by the magnet was proportional to the amount of Fe<NUM>O<NUM> added to the mixture with one exception.

This experiment demonstrates that the magnetic strength of the 6000GS permanent magnets employed in the above examples decreased exponentially (with <NUM><NUM> power) with distance from a magnet. The magnetic field strength of the permanent magnet was measured at increments from <NUM> to <NUM> distances. The results as shown in Table <NUM> illustrate the substantial decay of its magnetic strength. It is expected that electromagnetic bars will exhibit similar decay. With the present invention, the strength of the magnetic field generated by the magnets must be strong enough to activate the inducing paramagnetic substances to magnetize the diamagnetic substances as the diamagnetic and inducing paramagnetic substances interact. Given that magnetic strength decays dramatically with distance, it is necessary to keep the distance between sleeve holders to a relatively small gap as discussed previously.

With the present invention, in order to function as an effective magnetic filter to remove diamagnetic materials, the filter must use magnets, which can be permanent magnets or electromagnets, capable of generating sufficient magnetic fields to impart or induce the requisite magnetism in the diamagnetic materials so as to be attracted by a magnetic field. The intensity of the induced magnetism in the diamagnetic materials must to be strong enough to cause the attraction by the magnetic field. To demonstrate the importance of the magnetic field strength, <NUM>,<NUM> GS and <NUM>,<NUM> GS permanent magnetic bars were compared in a test similar to that in Example <NUM> where the magnets removed RFCC powders in water solution at room temperature.

The results are as summarized in Table <NUM> show that with the <NUM>,<NUM> GS magnet, only about <NUM>% of the mixed powder was attracted. The amount of paramagnetic powder present in the solution did not affect the level of attraction. In contrast, with the <NUM>,<NUM> GS magnet, <NUM>% and <NUM> % of the mixed powder was removed under a PM/DM ratio of <NUM> and <NUM>, respectively. Therefore, it is preferred to use magnets with higher magnetic strength to attract the diamagnetic substances through induced magnetism by the paramagnetic substances. The influence of the amount of paramagnetic powder present in the solution was comparatively less important with respect to the diamagnetic material being attracted.

Claim 1:
A method of removing diamagnetic material from a carrier stream that comprises the steps of:
(a) providing a housing having (i) a stream inlet, (ii) a stream outlet and (iii) an interior region (<NUM>) between the inlet and outlet which contains an inducement paramagnetic material (<NUM>) which is selected from the group consisting of Ce, CeO<NUM>, CsO<NUM>, Co, CoO, Ni, CuO, NiO, NiS, Fe, FeO, Fe<NUM>O<NUM>, FeS, Mn, Ni/γAl<NUM>O<NUM>, Cr<NUM>O<NUM>, Dy<NUM>O<NUM>, Gd<NUM>O<NUM>, Ti, V, V<NUM>O<NUM>, Pd, Pt, Rh, Rh<NUM>O<NUM>, KO<NUM>, and mixtures thereof;
(b) contacting a carrier stream comprising a carrier fluid and a diamagnetic material to the inducement paramagnetic material (<NUM>) within the region (<NUM>) wherein the diamagnetic material is selected from the group consisting of silicon, silicon carbide, γ-alumina, silica, silica/alumina, non-magnetic butadiene, magnetic butadiene, titanium oxide, ceramic, activated carbon, polyethylene, and elemental sulfur, and mixtures thereof and wherein the diamagnetic material comprises particles having a size in the range of <NUM> to <NUM>; and
(c) establishing a magnetic field within the region (<NUM>) thereby rendering the diamagnetic material sufficiently magnetic so as to be attracted by a magnet (<NUM>) to a yield a cleaned carrier fluid with reduced levels of the diamagnetic material wherein the diamagnetic material is magnetized under the magnetic field through coordinated interaction of the diamagnetic material and the inducement paramagnetic material (<NUM>).