DE102006056934A1 - Method for the centrifugal clarification of an oily sand - Google Patents

Abstract

Process for the centrifugal clarification of an oil sand, consisting at least of sand, water and hydrocarbons and hydrocarbon compounds, in a solid shell screw centrifuge (1) in hydrocarbons and hydrocarbon compounds and a sand-water mixture, whereby the oil sand to be processed is treated with water and / or or a solvent may be added, and wherein the solid bowl screw centrifuge comprises a drum (2) and a screw (3) comprising a cylindrical and a conical portion (6, 7), wherein in processing the oil sand into the drum another medium is initiated.

Description

The The invention relates to a process for the centrifugal clarification of an oil-containing Sandes in a solid bowl centrifuge according to the generic term of the Claim 1.

Put oil sands a geological formation (English: "oil sands" or "tar sands" or "bitumen sands" called), which in usually formed from a mixture of sands, bitumen and water. Oil sands supplies exist especially in Alberta in Canada, the US, Venezuela and Australia.

One typical oil sands in this region consists for the most part Percentage of sand, a few percent of bitumen and too few Percent of water.

The Bitumen is a kind of heavy oil of viscous texture. That, of course occurring bitumen is worked up to bitumen and synthetic crude oil.

Of the Sand of the oil sands is usually a mixture of sands and clay.

to Extraction of the bitumen, the sand is usually first hot water admixed and thus formed sludge in an extraction plant given where the liquid Skimmed off bitumen becomes. It is also known the oil sand / water mixture while adding an extractant.

The Mixture of bitumen, hot Water and minerals are called "froth" in English.

These Mixture has to go through the separation of water and minerals are cleaned. For this For example, the mixture typically becomes an organic solvent added as naphthene or hexane or various chemicals, which act as emulsion breakers.

typically, In this case, a gravity-assisted separation technique is used (Settling tank). additional Hydrocyclones and centrifuges of various types are also used.

In In particular, two types of centrifuges will be considered Centrifuges used. On the one hand, this is the solid bowl centrifuge with preferably horizontal axis and on the other to disc centrifuges (Separators) with vertical axis of rotation.

typically, become the oil sands cleaned in several stages. In a first stage, the separation of bitumen from the rest Ingredients carried out with the addition of water, for example in a settling tank. In the further purification stages then typically also come Hydrocyclones and / or decanter centrifuges are used.

there it is the task of the decanter or solid bowl centrifuges, Solids and other water from the usable hydrocarbon compounds to separate.

typically, solid bowl centrifuges are in the process in places used in which the to be prepared oil sand-water mixture a mixture from about 30 to 60 percent hydrocarbons or hydrocarbon compounds (e.g., bitumen plus organic solvents), Represents 30 to 60 percent water and 8 to 12 percent minerals.

there It is the object of the invention, the processing of the mixture in the solid bowl centrifuge so as to improve the proportion of hydrocarbons and possibly hydrocarbon compounds in the solid phase, which discharges the solid bowl centrifuge reduced becomes.

The Invention solves this object by the subject matter of claim 1.

advantageous Embodiments are to be taken from the subclaims.

According to the invention is in the solid bowl centrifuge next to the mixture to be processed initiated another medium.

To a first variant, the introduction of the medium takes place in the Solid bowl centrifuge with a cylindrical part and a tapering part in the cylindrical Section.

The Full-bowl screw centrifuge has a further inflow for this purpose on, which opens into the cylindrical portion of the drum, wherein the discharge of the further medium either close to the snail body or further radially outside can be done in the drum. Through the additional medium is the clarifying efficiency on the liquid side the decanter drum increases, so that more mineral particles accumulate inside the drum wall, from where they are fed by the screws to the solids discharge for discharge.

To In a second variant of the invention, the supply of the medium takes place by contrast, by a separate supply line in the conical part of the drum.

Here too, the clogging of the rest causes Medium further increasing the clarifying effect by an increased accumulation of minerals on the drum inner wall and an increased discharge of hydrocarbon fractions to the cylindrical end of the drum, where the liquid discharge is.

With the two variants of the invention - supply line in the conical part the drum and supply line in the cylindrical part of the drum - let each for himself improved clarification effects achieve a reduction of the remaining during operation of the plant Hydrocarbon fractions lead in the solids discharge, resulting in economic efficiency the use of the solid bowl centrifuges and the clarification of the to be processed mixtures significantly increased.

It There are different ways to do that additional Medium - at which can be, for example, water - the product to be added in the drum.

So it is conceivable both in the conical and in the cylindrical part, spray the medium in the decanter onto the product.

For this is a corresponding spray device to be installed inside the decanter drum.

alternative The medium can also be injected into the product.

Conceivable it is also to add it very close to the drum wall the product.

Important is to define the axial position of the additive.

He follows the addition on the cylindrical side, it makes sense a clogging close to the liquid outlet, whereas it makes sense on the conical side, the liquid in or on the drying zone to add the solid.

Conceivable it is finally also, the liquid at more than one axial and / or radial position, so the clarification continue to increase.

Also Again, that is also the multiple addition to different axial and / or radial positions on the cylindrical side close to the liquid outlet and on the conical side should be close to the solids discharge.

at The added medium may be fresh water on the one hand or other process water, that in the processing of the oil sands obtained in this or further process stages.

Conceivable it is finally also that the medium is not water but a dissolved liquid organic matter solvent like naphten, hexane or something similar or equivalent solvent is.

Conceivable is also the addition of any dissolved or undissolved chemicals, additives or emulsion breaker.

The Medium can finally itself also a mixture or a combination of the above Be means or media.

To a very particularly preferred variant is carried out by mixing devices - for example Pins or paddles in one or more flights - a mix the centrifuged material and the added medium in the drum. so especially good clarification results are achieved.

Stirs is preferably in particular the phase in which the medium is added becomes. The mixing is also preferably carried out at least in the axial Area of the drum (conical and / or cylindrical), in which also the medium is added.

Conceivable it is also, on the snail body mixing devices projecting into the drum - e.g. plow-like or paddle-like designed - to set and which also with a feed for the liquid in the centrifuged or the phase to which the medium was added is to provide. The invention thus also provides an inventive Centrifuge with this feature.

following the invention will be described in more detail with reference to the drawing.

It shows:

1 a schematic view of a schematic diagram of a solid bowl screw centrifuge according to a first embodiment;

2 a schematic view of a schematic diagram of a solid bowl screw centrifuge according to a second embodiment of the invention.

1 shows a solid bowl centrifuge 1 with a rotatable drum and an inside the drum arranged, rotatable at a differential speed to the drum screw 3 ,

The snail 3 has a snail blade 4 on, on the outer circumference of a screw body 5 is arranged.

The solid bowl centrifuge has a cylindrical area 6 and a tapered - conical - area 7 on.

At the end of the conically tapered area 7 is a solids discharge 8th designed for the discharge of solids S and at the cylindrical end 6 a liquid outlet 9 to discharge a liquid phase L.

The solid bowl centrifuge is also equipped with a first inlet 10 provided for the product P and with a second feed 11 for a medium M.

To 1 serves a centric inlet pipe as the first inlet 10 , which is surrounded concentrically by a second inlet tube of larger diameter, as the second inlet 11 serves.

The first feed 10 flows into a distributor 12 for feeding the product P to be processed into the interior of the drum.

The second inlet 11 on the other hand leads closer to the cylindrical end of the drum - ie the liquid outlet 9 into the interior of the drum.

To 2 on the other hand serves the inner inlet pipe 10 as a second inlet and the outer inlet pipe 11 as a feed for the product to be processed.

The second inlet 11 for the medium M opens here in the conical region of the drum.

In both embodiments, the product to be processed is an oil sand mixture, which is clarified in the drum with the addition of a medium M, wherein the addition of the medium at the liquid outlet 9 an increased proportion of hydrocarbons is derived as liquid phase L, whereas at the solids discharge 8th essentially a sand-water mixture from the drum 1 is directed.

at Both variants, the addition of the medium M, the remaining Proportion of hydrocarbon or hydrocarbon compounds in discharged solid F reduced in a simple manner.

1

Solid bowl centrifuge

2

drum

3

slug

4

screw blade

5

screw body

6

cylindrical Area

7

conical Area

8th

solids

9

liquid outlet

10

Intake

11

Intake

12

distributor

F

solid fuel

L

liquid phase

M

medium

P

product

Claims (23)

Process for the centrifugal clarification of an oil sand, consisting at least of sand, water and hydrocarbons and hydrocarbon compounds, in a solid bowl centrifuge ( 1 on the other hand, in hydrocarbons and hydrocarbon compounds on the one hand, and a sand-water mixture on the other hand, wherein water and / or a solvent are added to the oil sand to be processed before processing, and wherein the solid-shell screw centrifuge comprises a drum ( 2 ) and a snail ( 3 ) having a cylindrical and a conical region ( 6 . 7 ), characterized in that during the processing of the oil sand into the drum, a further medium is introduced. A method according to claim 1, characterized in that the further medium in the conical region ( 7 ) of the drum is initiated. Method according to one of the preceding claims, characterized in that the additional medium in the cylindrical region ( 6 ) of the drum is initiated. Method according to one of the preceding claims, characterized in that the additional medium in the conical section ( 7 ) close to the solids discharge ( 8th ) is introduced into the drum. Method according to one of the preceding claims, characterized in that the medium is close to the liquid discharge ( 9 ) is introduced into the drum. Method according to one of the preceding claims, characterized characterized in that the medium in half of the conical section is introduced, which adjoins the solids discharge. Method according to one of the preceding claims, characterized in that the additional medium in half of the cylindrical region ( 6 ) is introduced before the liquid discharge ( 9 ) of the drum is located. Method according to one of the preceding claims, characterized in that the additional medium in the drum ( 1 ) is sprayed onto the product. Method according to one of the preceding claims, characterized characterized in that the additional Medium in the drum is injected into the product. Method according to one of the preceding claims, characterized characterized in that the additional Product is introduced into the product near the drum inner wall. Method according to one of the preceding claims, characterized characterized in that the additional Product introduced into the drying zone of the product in the conical region becomes. Method according to one of the preceding claims, characterized characterized in that the additional Product at several axial or radial points in the product is initiated. Method according to one of the preceding claims, characterized characterized in that the additional Medium in the conical section and in the cylindrical area of the drum is introduced into the drum. Method according to one of the preceding claims, characterized in that in the conical region ( 7 ) and in the cylindrical region ( 6 ) different media are introduced into the product. Method according to one of the preceding claims, characterized characterized in that the additional Medium water is. Method according to one of the preceding claims, characterized characterized in that the additional Medium is naphthene or hexane. Method according to one of the preceding claims, characterized characterized in that the additional Medium a dissolved or unresolved Chemical is. Method according to one of the preceding claims, characterized characterized in that the additional Medium is an additive or an emulsion breaker. Method according to one of the preceding claims, characterized characterized in that by mixing a mixing of the Spun and the added medium in the drum takes place. Method according to one of the preceding claims, characterized characterized in that the mixing is preferably at least in the axial Area of the drum takes place, in which also the medium is added becomes. Method according to one of the preceding claims, characterized characterized in that mixing pens or paddles in one or several Schnekkengängen be used. Method according to one of the preceding claims, characterized characterized in that for mixing from the screw body into the drum projecting Mixing devices - e.g. plow-like or paddle-like - used. Method according to one of the preceding claims, characterized in that the mixing devices have an inlet for the medium are provided in the drum.