DE102007028737A1 - Method for preparing rolling oil from mixture of rolling oil and xenobiotic, involves bringing mixture of rolling oil and xenobiotic in contact with liquid extracting agent under agitation in agitator containers - Google Patents

Abstract

Rolling oil preparation involves bringing a mixture of rolling oil and xenobiotic in contact with a liquid extracting agent under agitation in agitator containers (1,1.1) at ambient pressure and temperature to extract the rolling oil from the mixture. The extracting agent is evaporated from the resultant mixture of rolling oil and extracting agent. 1-10, preferably 3 carbon containing hydrocarbon is used as extracting agent. Boiling point of the hydrocarbon is different from the boiling point of the rolling oil. An independent claim is also included for a device for the execution of the method, which has an agitator equipped with extraction container.

Description

The The invention relates to a process for separation and treatment of rolling oil from a rolling oil / foreign substance mixture. The term "foreign matter" is primarily water, metallic abrasion particles and filter aids.

At the Rolling of steel, stainless steel and non-ferrous metals and also at Other metalworking usually fall Abriebspartikel on, by the rolling oil or other oil or removed an emulsion of water and rolling oil from the nip and usually immediately afterwards in special Filters are removed from the liquid.

at the filters are either precoat filters with z. As diatomaceous earth as a filter aid or candle filter, the without Filter aids get along. When using filter aids a ternary mixture of filter aid, abrasion particles forms and rolling oil, while in candle filters a Binary mixture of abrasion particles and z. B. rolling oil forms.

State of the art

For the treatment and conditioning of circulated rolling oil is in the DE 199 05 817 C2 describes a method in which dirt and abrasion particles are removed from the used rolling oil under controlled supply of filter aids by filtration, in particular for the treatment of rolling oil from aluminum foil rolling mills in the rolling oil, an electrical conductivity is adjusted to the risk of electrostatic charging of the abrasive particles prevent their sparks discharge fires, explosions or deflagrations in the rolling mill. As a filter aid, a flocculant is used to agglomerate the ultrafine particles to larger aggregates, the amount of which is regulated depending on the residual contamination remaining in the filtrate such that a predetermined minimum conductivity caused by the remaining residual contamination is retained in the filtrate.

In the EP 0 597 803 A1 a method for cleaning rolling oils is described which contain abrasion particles of the processed into band-shaped semi-finished metals as a dirt oil. In this process, dimer acid is added to the dirty oil and the mixture is passed through a coagulator, whereby the abrasive particles coagulate and are separated from the dirty oil. The purified oil can be reused in the circulation as rolling oil.

For the treatment of contaminated waste oil, especially used paraffin oil, is in the DE 42 35 213 C2 described that by using suitable extraction means, the possibility exists of agglomerating the impurities, wherein the used extraction agent can be recovered after completion of the discharge of the agglomerated contaminants by subsequent distillation and recycled into the process cycle. For agglomeration of the impurities, it is proposed to use an extractant mixture of a polar and a non-polar solvent, that is, for example, a mixture of 50% isopropanol and 50% acetone.

The DE 602 11 041 T2 describes a process for the regeneration of petroleum-based waste oil by extraction with aliphatic solvents, followed by removal of the extraction solvent followed by different separation stages, namely separation of the light products by distillation at atmospheric pressure, separation of the gas oil and the base oils or base oils by vacuum distillation and a final refining of Oils (base oils).

The inventive method is simplified and thus cost-effective separation of a ternary mixture in oil, filter aids and abrasion particles or a Dual-substance mixture in oil and abrasion particles by extraction and optionally for the treatment of the oil phase by adsorption.

Around To achieve this goal is the invention Process for the preparation of rolling oil from a rolling oil / foreign substance mixture by characterized in that the rolling oil / foreign substance mixture under Stir in a stirred tank with a liquid extractant at ambient pressure and Ambient temperature is brought into contact to leave the mixture to extract the rolling oil and then into a second stage of the resulting rolling oil / extractant mixture to evaporate the extractant.

For the case that connected to the extraction stage an adsorption stage is, is provided according to the invention, that the Adsorption treatment is carried out in the same container like the extraction treatment. In the event that a ternary mixture, consisting of rolling oil, metallic abrasion particles and Filter aid can be prepared according to further Invention for separating the rolling oil and extractant existing liquid phase of the from abrasion particles and Filter aid existing solid phase both in the extraction stage as well as in the adsorption stage of those used in the extraction stage Precoat filter also as precoat filter in the adsorption stage to be used.

The The invention will be described with reference to the drawings:

1 shows a flow chart of the extraction stage;

2 shows a flow chart of an optional subsequent to the extraction stage adsorption stage;

3 shows a schematic representation of an embodiment of an extraction plant according to the invention.

In the 1 The extraction stage shown contains one with a stirrer 1.1 equipped extraction tank 1 , A ternary mixture consisting of rolling oil, abrasion particles and filter aid (eg kieselguhr) is introduced into the extraction vessel under an inert gas atmosphere together with a liquid extractant at ambient pressure and ambient temperature 1 filled. With the stirrer 1.1 a homogeneous suspension is produced, which after a relatively short residence time in the extraction vessel 1 with a suspension pump 1.4 to a precoat filter 2 is encouraged. In the precoat filter 2 The solids are retained as filter residue, while the mass of the rolling oil and the extractant the filter 2 as a filtrate happened. In this precoat and filtration process, the rolling oil concentration in the void volume of the filter residue is lowered to a tolerable low value of about 1% by sufficient long rinsing with fresh extractant.

The remaining in the precoat filter solid can then still a press 2.1 be fed to squeeze out the remaining liquid phase. The filter cake then passes under exclusion of air in a dryer 5 in which the residual, volatile extractant is removed from the void volume of the filter cake. The dry solid then passes through a magnetic separator, for example via a conveyor belt 6 to separate the magnetizable particles from the solid. These particles, which in particular contain Cr and Ni containing precious metals and correspondingly valuable particles, can then be reused as raw material in the melting process. In principle, the regenerated filter aid can be used again for the filtration, whereby the filter aid circuit is closed.

The filtrate from the precoat filter 2 , ie the liquid mixture of rolling oil and extractant, with the behind the press 2.1 resulting liquid phase an extractant-evaporator 3 supplied in the abs at a vacuum of about 500 mbar. the extractant completely evaporated. A compressor 3.1 then conveys the extractant vapor into an extractant condenser 4 , in which condenses at ambient pressure and a condensation temperature <25 ° C, the extractant vapor. The compressor 3.1 is designed so that the vaporous extractant from the dryer 5 also in the condenser 4 can be promoted. The resulting liquid extractant can then be returned to the extraction vessel 1 be promoted, whereby the extractant circuit is closed.

The The evaporator leaving, purified rolling oil is in a Quality recovered, which is a direct reuse allowed in the rolling process, whereby the rolling oil circuit closed is.

If the extracted rolling oil is not reused in the rolling process It should, in particular following an adsorption treatment for example as a base oil in the lubricant industry or used in the chemical industry.

In the 2 illustrated, optionally subsequent to the extraction stage adsorption contains one with a stirrer 7.1 equipped adsorption tank 7 on which a precoat filter 8th follows. According to the adsorption for the adsorption as adsorption 7 and precoat filters 8th the extraction containers previously used in the extraction stage 1 or precoat filter 2 used to reduce the overall size of the system as much as possible.

The extracted rolling oil, but also any other oils from other sources can with a sufficient amount of effective as adsorbent bleaching earth in the adsorption 7 be filled in with a stirrer 7.1 equipped. The bleaching earth adsorbs residual polar elements of the preheated base oil. The suspension is now by means of a suspension pump 7.4 to the precoat filter 8th pumped, which passes the base oil and holds the bleaching earth as a solid. As soon as the precoat filter is filled with laden bleaching earth, the latter is squeezed out in order to extract as much oil as possible. The squeezed bleaching earth is disposed of without further treatment, while the oil can be used as intended.

Instead of of bleaching earth to be used once can also be regenerated Solid adsorber can be used.

These Apparatus arrangement is suitable for both liquid / liquid extractions as well as for solid / liquid extractions and for the subsequent adsorption treatment of the previously produced extracts.

3 shows a schematic representation of a preferred embodiment of an extraction plant, which can also be used as adsorption. In the 3 Bracketed numerals indicate that these plant components are associated with an adsorption stage.

• – einem Rührwerksbehälter 1 mit Rührwerk 1.1, dem Behälter 1.2 für das zu behandelnde Dreistoffgemisch, der Dosiereinrichtung 1.3 mit Inertisiereinrichtung 1.5 und Evakuiereinheit 1.6 sowie der Suspensionspumpe 1.4 für die Suspension aus Dreistoffgemisch und Extraktionsmittel
• – einem Anschwemm-Filter 2 mit integrierter Presse 2.1
• – einem Extraktionsmittelverdampfer 3 mit einem angeschlossenen Verdichter 3.1 und einem Wärmetauscher 3.2
• – einem Extraktionsmittelkondensator 4 mit einem Wärmetauscher 4.1, einem Kältemittelverdichter 4.2 und einer Drossel 4.3
• – einer angeschlossenen Extraktionsmittelpumpe 4.4
• – einem Trockner 5 mit beheizbarer Förderschnecke 5.1 einschließlich einer Austragsschleuse 5.3 mit Belüftungseinrichtung 5.2 und der Vakuumpumpe 5.4
• – einem Magnetabscheider 6 mit Förderband 6.1
• – einer Hilfsheizung 9 und
• – einer Hilfskühlung 10.

The plant consists of

• - An agitator tank 1 with stirrer 1.1 , the container 1.2 for the ternary mixture to be treated, the metering device 1.3 with inertizing device 1.5 and evacuation unit 1.6 and the suspension pump 1.4 for the suspension of ternary mixture and extractant
• - a precoat filter 2 with integrated press 2.1
• - An extractant evaporator 3 with a connected compressor 3.1 and a heat exchanger 3.2
• An extractant condenser 4 with a heat exchanger 4.1 , a refrigerant compressor 4.2 and a throttle 4.3
• - An attached extractant pump 4.4
• - a dryer 5 with heated auger 5.1 including a discharge lock 5.3 with ventilation device 5.2 and the vacuum pump 5.4
• - a magnetic separator 6 with conveyor belt 6.1
• - An auxiliary heater 9 and
• - an auxiliary cooling 10 ,

• – der Rührwerksbehälter 7 mit Rührwerk 7.1, Bleicherdevorrat 7.2, Dosiereinrichtung 7.3 und Suspensions-Förderpumpe 7.4
• – der Anschwemm-Filter 8 mit Pressvorrichtung 8.1 und separaten Entnahmeleitungen 8.2 und 8.3

verwendet werden, die bis auf die Positionen 8.2 und 8.3 identisch mit den entsprechenden Positionen der Baugruppen 1 und 2 sind.For the adsorption treatment can

• - The agitator tank 7 with stirrer 7.1 , Bleaching earth stock 7.2 , Dosing device 7.3 and suspension feed pump 7.4
• - the precoat filter 8th with pressing device 8.1 and separate sampling lines 8.2 and 8.3

to be used, down to the positions 8.2 and 8.3 identical to the corresponding positions of the modules 1 and 2 are.

Out of the container 1.2 is via the metering device 1.3 a defined ternary mixture amount predetermined. With the vacuum pump 1.6 will be in the metering device 1.3 de-aerated bed and subsequently on the device 1.5 rendered inert. The bed falls into the agitator tank 1 and is there via the extractant pump 4.4 and the agitator 1.1 mixed with a defined amount of extractant.

The suspension pump 1.4 promotes the suspension to the precoat filter 2 , After sufficient loading of the precoat filter 2 with solid, the filter cake with the press 2.1 squeezed out as much liquid in the evaporator 3 to get to.

The squeezed solid can either in the agitator tank 1 be returned to there to be added again with extractant, or he gets into the dryer 5 , The dryer 5 contains a motor driven (M), heated auger 5.1 and a heating mantle 5.2 , The dried solid reaches a discharge lock 5.3 in which the solid by means of a vacuum pump 5.4 degassed and by means of a ventilation device 5.5 can be ventilated. After the air supply, the solid can pass through a conveyor belt 6.1 discharged and by means of magnetic separator 6 be freed from magnetizable metal particles.

That the precoat filter 2 leaving liquid mixture of extractant and oil is in an evaporator 3 promoted, by means of heat exchangers 3.2 is heated. The extractant vapor is passed through a compressor 3.1 in the extractant condenser 4 promoted and condenses there on the outer wall of a radiator 4.1 which is in a refrigerant circuit with compressor 4.2 and throttle 4.3 is involved.

Both the heat supply in the evaporator 3 as well as the heat dissipation in the condenser 4 can by an auxiliary heater 9 or by an auxiliary cooling 10 get supported.

The liquefied extractant is above the pump 4.4 in a closed circuit again available, the extraction agent-free rolling oil is removed as the filter aid and the metallic abrasion particles from the plant.

If necessary, after the extraction step, an adsorption treatment can be connected. In addition, the agitator reactor will again 1 as adsorption container 7 and the precoat filter 2 (8) needed.

The bleaching earth is removed from the bleaching earth container 7.2 , about the metering device 7.3 in the agitator reactor 7 given and there by means of agitator 7.1 intensively mixed with rolling oil or other recovered oils passing through the pump 4.4 be fed into the agitator tank.

The suspension pump 7.4 promotes the suspension in the precoat filter 8th , in which, even with the involvement of the press shop 8.1 as much base oil as possible is pressed out of the solids. The base oil can then immediately over the line 8.2 be removed and recycled, while the used bleaching earth on the separate line 8.3 is disposed of.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19905817 C2 [0004]
• - EP 0597803 A1 [0005]
• - DE 4235213 C2 [0006]
• - DE 60211041 T2 [0007]

Claims (12)

Process for the preparation of rolling oil from a rolling oil-foreign substance mixture, characterized in that the rolling oil-foreign substance mixture with stirring in a stirred tank ( 1 ; 1.1 ) is brought into contact with a liquid extractant at ambient pressure and ambient temperature and thereby becomes pumpable, in order to extract the rolling oil from the mixture, and then in a second stage ( 3 ; 4 ) from the resulting rolling oil / extractant mixture to evaporate the extractant. Method according to claim 1, characterized in that that for separating the extractant from the rolling oil required heat of vaporization by a heat pump taking advantage of the heat of condensation of the separated Extraction agent is provided. Method according to one of claims 1 to 2, characterized in that the extractant in the closed Circulation is performed. Method according to one of claims 1 to 3 for the preparation of a ternary mixture, consisting of rolling oil, metallic abrasion particles and filter aids, characterized that is followed by the suspension of the extraction stage Ternary mixture and extractant a filter, preferably Precoat filter feeds, from which the rolling oil / extractant mixture to evaporate the extractant to an evaporator, while the solids as a filter residue one Drier and then fed to a Magnetabschneider be used to separate magnetizable particles from the solid. Method according to one of claims 1 to 4, characterized in that the extractant is a hydrocarbon with one to ten C-atoms, preferably with three to eight C-atoms is used, the boiling point of the boiling range of the rolling oil is different. Method according to one of claims 1 to 5, characterized in that the rolling oil in successive following extraction steps almost completely from the Solid particles is separated. Method according to one of claims 1 to 6, characterized in that the extracted rolling oil a equipped with a stirrer adsorption feeds to remaining polar elements of the oil preferably to adsorb using bleaching earth. Method according to claim 7, characterized in that that is the oil and adsorbent suspension subjected to a filtration process to remove the oil from the Separate adsorbent. Method according to Claims 7 to 8, characterized that as adsorption and subsequent Filtrationsstufe the extraction tank and the at this Extraction tank subsequent filter used. Device for carrying out the method according to claim 1, characterized in that it comprises a stirrer ( 1.1 ) equipped extraction vessel in which the rolling oil / foreign substance mixture is prepared with a liquid extractant to a pumpable suspension, that on the extraction vessel a precoat ( 2 ) follows, to the for further treatment of the extraction agent and oil existing liquid phase, an extractant evaporator ( 3 ), to which an extractant capacitor ( 4 ) for the return of the liquefied extractant to the agitator tank ( 1 ; 1.1 ) and that for the preparation of the filter residue forming solid phase on the precoat a with a screw conveyor ( 5.1 ) dryer followed, to which a separating device ( 6 ; 6.1 ) for separating filter aid and metal particles. Apparatus according to claim 10, characterized in that to the evaporator for further treatment of the separated in the evaporator from the extractant oil with a stirrer ( 7.1 ) equipped adsorption container ( 7 ), which can be charged with an adsorbent, preferably in the form of bleaching earth, in order to adsorb residual polar elements of the oil, and to the adsorption vessel ( 7 ) a precoat filter ( 8th ) is connected to separate the purified oil from the adsorbent. Apparatus according to claim 11, characterized in that as Adsorptionsbehälter ( 7 ) and subsequent precoat filter ( 8th ) the agitator container ( 1 ; 1.1 ) with the attached precoat filter ( 2 ) serves.