DE1719409A1 - Procedure for handling fine-grained or powdery material - Google Patents

Description

Continental Oil Company, Ponca City, Oklahoma, U.S.A.

Method of handling fine-grained or powdery

material

The invention is concerned with the handling of fine-grained or powdery material and in particular with the Storage and transport of fine-grained material such as coke or sulfur in the form of a slurry a pipeline.

It is known that relatively fine-grained materials in similar way liquids can be handled. "Such fine-grained and powdery substances often bake but r.chon together and are with a relatively short storage time then no longer without other things in as convenient a way as liquids to treat. Rather, the quasi-liquid state must only through mechanical destruction and dissolution of the lumps and deposits formed and possible sieving again, restored; ' been. It has already been suggested the powdery material to avoid the buzzing up ..- "'.-

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keep moving continuously by stirring, so that no deposits can form. This proposal is because of the additional energy required and the associated costs are not practicable to any arbitrary extent, and it does not include a solution for the case the temporary cows of the material. The problem is particular particularly characteristic for the handling of dry material and it has therefore also been suggested that Determines fine-grained and powdery substances in one

slurry suitable carrier liquid and in this Further handling of the mold, e.g. pumping through a pipeline. However, caking cannot be prevented satisfactorily in all cases even by this measure. In addition, with this proposal it has proven difficult in some cases to remove the solid from the carrier liquid to be separated again and to keep it free from the carrier liquid. Some of the fluid often stays with the The surface of the material is adsorbed and thus lost. When using vVasser or other relatively worthless carrier liquids If the loss is irrelevant, with other liquids, e.g. with hydrocarbons, this loss can but be an obstacle to the economic conduct of the process.

The problem, fine-grained or powdery material quickly, easily and without economic loss, without noticeable caking and without noticeable loss of carrier liquid to handle and transport when using a slurry has not yet been solved satisfactorily despite numerous attempts in this area.

The method according to the invention for the production of a slurry of fine-grained material that does not clog even at rest

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or powdery material, e.g. coke breeze or sulfur, in one Carrier liquid; for storage and transport through pipelines is characterized in that .. that the Eornoberflachen des Materials initially with a 'with the liquid not miscible inert, preferably adhering, liquid protective agents are wetted and the wetted material then in itself. known method is suspended in the carrier liquid.

A slurry of fine-grained material produced according to the invention does not separate any caking sediment even when standing for a long time and is consequently ideally suited for transporting the slurried material through a pipeline and for storing the material. A later separation of the solid material from the carrier liquid int M is possible without difficulty and without significant loss of carrier liquid.

In carrying out the method according to the invention, the pulverulent material is mixed with a sufficient amount of the protective agent. The protective agent is adsorbed on the surface of the material. The powdery material with the adsorbed protective agent is then processed together with the carrier liquid to form the slurry. This slurry can then be stored for any length of time without it caking or it can also be pumped through a pipe without caking in the pipe and clogging the pipe. : v. ■■■■■■■: ν '; : ■ I: V ■; A.

In the manner according to the invention can be very different and numerous materials are handled and transported. In general, it is only necessary that the substances are relatively fine-grained or powdery. The material can be of 'uniform' or 'different' grain, as can the The shape of the particles is not essential; certain restrictions will be given later. In the manner according to the invention,

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for example: sulfur, coke, ores and, of course, occurring salts such as Potash, phosphates, cryolite, bauxite, also coal, grated or pelletized plastics such as polystyrene or polyethylene and others. The process is of particular importance for the handling of coke and sulfur.

To avoid technical difficulties when pouring the slurry made according to the present invention has it It has been found necessary to comminute the material to a grain size of at most 12.7 eggs prior to treatment. If possible, grain size diameters greater than 6.4 mm should be avoided. Even finer materials can do without Restriction can be handled in the manner according to the invention if appropriate apparatus are available that Separate slurry again later. Grain sizes from 1 Microns are easy to handle.

The protective agent to be used according to the invention must be below be selected according to certain criteria and must have the following properties:

a) It must be inert to the powdery material and the carrier liquid

b) It must be immiscible with the carrier liquid.

c) Compared to the carrier liquid, it must preferentially wet the powdery material.

Any liquid that meets these requirements is suitable as a protective agent for the purposes of this invention.

Depending on the type of material to be handled and the available carrier liquid, there are a large number of Liquids to choose from as a protective agent. Possible are, for example:

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Water and liquid hydrocarbons such as isopentane, hexane, heptane, gasoline, kerosene or diesel and also bunker oil, aromatic hydrocarbons such as benzene, toluene and X7 / I0I and their derivatives including alkylated aromatics such as bodecylbenzol, octyltoluene and similar hydrocarbons. Furthermore, primary, secondary or also tertiary alcohols with one to six carbon atoms or any desired mixtures can be used . '. Mixtures of such alcohols are used as protective agents for the purposes of this invention. Acetone, butanone (2), pentanone (3) or other ketones can be used, as can dichloromethane, carbon tetrachloride, dichloroethane or other halogenated hydrocarbons. Should be handled sulfur in the inventive manner, including carbon disulfide is a SITUATE A designated retardant.

Sufficient to achieve the intended effect The lack of protective equipment depends on the material and the speed at hand its surface quality. The most effective mange is generally the amount of protectant necessary to saturate the material with it. But it's going to be a lot satisfactory results are obtained when less protective agent is used than at almost complete saturation. supply of the powdery material is necessary. A sufficient amount of protective agent is therefore generally regarded as the amount the 50% by weight of the amount necessary for complete saturation is equivalent to. Preferably, however, not just 50% but et v / a 90% of the amount necessary for complete saturation used.

As far as compatible with the conditions that are placed on the protective agent, it also stands as a carrier liquid for the various Jiulverigen materials to be handled a great deal Choice available. The carrier liquid must be compared to the other components of the system be inert and they must be under be purnpar under the conditions in a pipeline. Inside this

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Within the framework, the choice of the carrier liquid is determined by the type of material to be handled and the protective means. For example, any liquid hydrocarbon including the above-mentioned hydrocarbons and also crude oil as a carrier liquid under certain conditions Find use. If a hydrophobic preservative has been chosen, water or brine will be used if possible can be used as a carrier liquid, and generally water or a brine is used because of its value for money and any availability as a carrier liquid find preferred use.

™ The solids content of the slurry can also be within vary over a wide range. It. it has been found that slurries with a content of up to 95% by weight of solids and protective agents are possible under good pumping conditions. Preferably, slurries with a Solids and preservative content of about 30 to 60% by weight, based on the total weight of the slurry used, since such concentrations require less energy to pump. A concentration of 50% of coke and For example, water in kerosene has proven to be optimal for such a system. Mixing preservative and powdery Material for the purpose of wetting can be used in any way

h take place. Usually you will add the powdery material to an excess of protective agent and mix or stir with one another until the material is completely wetted by the protective agent. The amount of protective agent required in each special case for a certain material and a certain grain size can generally be determined beforehand. However, this prediction is not necessary and it is easier to use an excess of protective agent. The excess amount that is not adsorbed can simply be drained off or allowed to drain off at the bottom of the mixing vessel. A slight excess of no more than about ^r f / O protectant

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is without disadvantage for the properties: the suspension and can be left on the material. In the case of more valuable protective devices, it should be appropriate for economic reasons be to remove the excess by removing it.

The material wetted with the protective agent can then be processed in a known manner with the carrier liquid to form a slurry. Usually you will pump the wetted material into the pipeline in which the Carrier liquid is located. Through different Purap speeds of carrier liquid and solid material when pumping into the pipeline, slurries of any concentration can be obtained. The slurry can also can be prepared in a larger tank or boiler by mixing the components. The slurry can then be pumped from the tank into the pipeline or can also be stored in the tank.

In the same way as the preparation of the slurry by mechanical means can be carried out in a known manner without particular difficulties, so is the subsequent separation of the components of the slurry using known apparatus and procedures. Preferably one will use a Hydrocyclcn and the material if necessary run through several times according to the desired degree of unity. With a very small grain size of the solid material it is appropriate to use the liquid draining from the hydrocyclone Slurry medium to be clarified through filter cloths. By however, such filtrations generally need to be able to remove particles less than about 5 microns in diameter. Other measures such as flotation, gel precipitation and simple filtration can be used to separate the slurry will.

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The protective agent adsorbed on the powdery material can in some cases be left on the material after the separation of the slurry, in other cases it is desirable to free the material from the protective agent or to recover the protective agent. The procedure to be followed depends on the specific materials used; In principle, all can be used for such operations known 'A ^r ege be taken. In general, it will be easiest and most advantageous to make the protective agent evaporate by heating the material. If, for example, 7 / ater is applied to coke as a protective agent, it is sufficient to heat the moist coke to about 15Ο C in order to dry it completely. If, on the other hand, at the temperatures required for evaporation, at least partial decomposition or change in the protective agent or powdery material is to be expected, other methods must be used, be it heating under reduced pressure or removal of the protective agent using a selective solvent.

The process according to the invention can be used with great advantage for the production of a slurry of coke breeze in a hydrocarbon, preferably gasoline or kerosene. In this case, water serves as a protective agent. In such a coke / water / hydrocarbon system, W is preferably operated with a slurry which contains about 40 to 60% by weight of moist coke. When wetting the coke with the water, temperatures of about 60 ° C. and more are preferred; it is best to saturate the coke with water vapor.

As already stated, for each of the three components, the 'best, nd parts of the slurries to be produced according to the invention are a large number of substances and compounds in

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Consider that used in certain combinations with each other can be. The following table lists examples of such combinations that can be used advantageously:

Table I.

powdery material to be handled

Sulfur coal

Polyethylene chips sulfur

Potash Cryolite Polystyrene Coke

Potash

Protective agent

Kerosene

water

toluene

Sulfur! Carbon

Glycerin

Water-

Xylene

water

Glycerin

Carrier liquid

Water bunker water water

Gasoline kerosene water gasoline crude oil

example 1

About 15 g of sulfur powder with a grain size between about 5 microns and 5mm are poured into kerosene. The mixture is stirred vigorously and divided into two halves. The excess kerosene is allowed to drain off the first half, from the other half it is removed by removing it. Then the sulfur wetted with the kerosene becomes mixed with water to form slurries, each 30% by weight contained in wetted material. Bake these slurries after standing flush in a beaker for twelve o'clock.

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As far as the sulfur has settled, a uniform The suspension can be restored by simply inverting the closed beaker.

An approximately 30% slurry was also used for comparison of the same sulfur in water produced without the inventive wetting with a protective agent. When standing the sulfur quickly settled at the bottom of the jar and was essentially caked together after 12 hours. To restore a suspension, the vessel had to be shaken vigorously for a long time, simply inverting it as in the wetted sulfur had no effect.

Example 2

A coke-kerosene slurry was made in the following vessel configuration tested:

Inlet and outlet nozzles of an open-topped container with a capacity of about 120 liters are via a 3/4 "pipe loop from connected to each other about 9 m in length. At a distance of about 1.5m from the container outlet there is a centrifugal pump in the Built-in pipe loop that can run at different speeds and is used to pump the contents of the tank. A clear piece of pipe is installed about halfway along the pipe loop through which the flow control ™ conditions inside the pipe can be observed.

The container and the pipeline were filled with kerosene. First was coke that was not treated with a protective agent was stirred into the kerosene until a suspension of about 35% solids content was formed. Then the Pump started so that the suspension flowed turbulently in the pipe loop. First of all, with regard to the The flow of the coke-kerosene slurry poses no problems

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on. In order to simulate a standstill, the pump was then switched off and the system was left to stand for about 15 hours. After this time it was found in the pipeline that the coke had settled and the. overlying corrosion layer was relatively clear. The coke deposit had caked up and it was not easily possible to restart the system under the same flow conditions as before. Relatively large lumps of the caked coke were torn loose and clogged the system in several places. It was necessary to run the pump so that there was laminar flow in the pipe and to restart it was necessary to temporarily pump pure kerosene instead of the slurry. But even with the initial pumping of pure kerosene, the caked coke nic-uo was easily poured out again but mostly remains compact on the ground. It was not possible to operate the test plant with a 4-0% coke slurry because the line was completely blocked. The coke-kerosene slurry was then separated using a hydrocyclone and the relatively dry coke was heated to dislodge adsorbed kerosene. It was found that approximately 12% of the kerosene used in the system was lost by adsorption on the coke and that temperatures above 50O ⁰ C were necessary to desorb the adsorbed kerosene from the coke.

A portion of coke was then mixed thoroughly with excess tap water and the excess water drained off permit. The coke wetted with '.Yasser was then in the Container mixed with fresh kerosene, the mixture being constantly agitated as before with the addition of the coke. the Restilatory slurry contained about 50% by weight of wet Coke.

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The slurry was then passed through the test facility Pipe loop pumped so that it flowed turbulently. Included no trouble was observed. The pump was then taken out of service and the system for 15 hours left alone. After this time the coke was not caked and when the pump was restarted it was the slurry moves through the system instantly and without clogging. There were no special praise for this such as temporary pumping of pure kerosene or increased pumping speeds required.

A portion of the slurry was withdrawn from the system and placed in separated by a hydrocyclone. The water-moist coke was then heated to about 1.50 ° C. in order to desorb the water. Included it was found to be about 1.5% of the kerosene used in this Way of working get lost.

Example 3

About 120 g of coke with a grain size of about 50,000 uikron were poured into a container filled with water. After stirring, the excess water was allowed to drip off and the coke so wetted with water was mixed with the appropriate amount of regular gasoline to form a JO ^ igen slurry. This slurry was poured into a beaker and allowed to stand for 12 hours. It was observed that within this time coke does not cake. As far as the coke had settled, the suspension could in which gasoline can be restored by simply turning the container inside out.

For comparison, the same coke became about 30% above Slurry made in regular gasoline without pre-moistening with water, also using about 120 g Coke. With otherwise the same treatment and under the same conditions

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fertilize-had itself. "after 12 hours a caked Sediment formed by coke. In order to make the suspension in the gasoline up front, the cup had to take a long time violently shaken, simply turning inside out as before was without any effect.

The slurry of water wet coke in the gasoline was separated by filtration and the coke dried by heating at 150 ⁰ C. In the same way, the untreated coke was separated from the gasoline slurry by filtration and heated to drive off the adhering gasoline. No loss of gasoline was observed on drying the water-wet coke, while heating the non-water treated coke stripped an amount of gasoline from the coke equivalent to about 12% of the gasoline used in the slurry, that is, about 12% of the Carrier fluids were lost through adsorption on the coke, and heating to about 500 ° C. was necessary to completely remove the gasoline from the coke.

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Claims (10)

Claims 1. A process for the production of a slurry of fine-grained or powdery material, such as coke or sulfur, in a carrier liquid, which does not stick together even at rest, in particular for storage and transport through pipelines, characterized in that the grain surfaces of the material initially have an inert, preferably adherent, liquid protective agent which is immiscible with the carrier liquid is wetted and the wetted material is then suspended in the carrier liquid in a manner known per se. 2. "The method according to claim 1, characterized in that the grain surfaces of the material are at least 50 / o, preferably more than 90% wetted with the protective agent. 3. A method for producing a slurry of coke in gasoline according to claim 1 and 2, characterized in that water is used as a protective agent. 4. Process for the preparation of a slurry of sulfur in water according to Claim 1 and 2, characterized in that carbon disulfide is used as the protective agent. 5. Process for producing a slurry of sulfur in water according to claims 1 and 2, characterized in that kerosene is used as the protective agent. ORIGINAL BATHROOM 10 9 8 2 3/2159 171 6. A method for producing a slurry of coal in bunker oil according to claim 1 and 2, characterized in that water is used as the protective agent. 7. Process for producing a slurry of potash in crude oil or in normal gasoline according to claims 1 and 2, characterized in that glycerine is used as a protective agent. 8. A method for producing a slurry of cryolite in kerosene according to claim A and 2, characterized in that water is used as the protective agent. 9. Process for producing a slurry of polystyrene in water according to Claims 1 and 2, characterized in that xylene is used as the protective agent. 10. A method for producing a slurry of polyethylene in Y / water according to claim 1 and 2, characterized in that toluene is used as the protective agent. 109823/7159 ORlGSMAL BATHROOM