GB2127430A - Process and equipment for the continuous production of lubricating grease - Google Patents

Abstract

In a process and apparatus for making grease, saponification in an oil medium takes place in a reactor (16), water produced in the saponification and/or other solvent is removed in an evaporator (17), the grease base is fed into a heat-treatment device (18), optionally together with further oils and/or additives, and then into a cooler and homogenizer (19). One or more of the saponification reactor (16), the heat treatment device (18) and the cooler (19) is a static mixing duct (1) containing separation walls (2) dividing the duct into tapering chambers (I, V and VII), and flaring chambers (II, IV and VIII) into which components are fed. Because of the changing flow cross-sections of the chambers, components fed therein are accelerated or decelerated, and a stream that has passed through a tapering chamber is contacted with a stream that has flowed through a flaring chamber when those streams have unequal flow velocities, thereby bringing about intimate contact of the streams. <IMAGE>

Description

SPECIFICATION Process and equipment for the continuous production of lubricating grease The invention relates to a process and an equipment for the continuous production of lubricating grease.

It is well known that the process of lubricating grease production depends on the type of the applied gelling component, however, the process mainly consists of saponification, of dehydration ofthe water andior solvent content resulting from saponification introduced into the system and/or of desolvation thereof, of the dispersion ofthe soap melt, cooling and homogenization.

From the point of view of operation saponification comprises mixing of the components and applying the heattransfer needed forthe acceleration of reactions. In case of preformed soaps or other types of gelling substances this operational step is omitted.

Dispersion takes place partly simultaneously with saponification, as in the majority of the known processes saponification is performed in a mineral oil medium. Dispersion can be improved by mixing, dissipation heattransfer and by applying a shearing effect.

Water and/or solvent content resulting from saponification and introduced into the system is removed by de-hydratation and/or desolvation. In the course of modern continuous processes this is mostly performed in film-evaporators provided with stirring blades. By the proper formation ofthe rotating part of the rotaryfilm-evaporators it can be achieved that the material to be heated, to be dehydrated and/orto be desolvated- being present in form of a rather thin film -shouldcontacttheheattransferringsurface,with an intensiveturbulence and for a very short period.In the case of non-Newtonian liquids and of high viscosity, in the medium formed in the bow-wave overheating detrimental forthe material prectically cannot arise and deposition and gumming up on the wall become impossible due to the material film being renewed continuously by the high number of revolution of the rotor.

Formation of the gel structure, meaning crystallization of the soap melt and suitable dispersion, takes place in the equipments for heat-treatment and cooling.

Cooling is often conducted by adding the missing part of the oil component or by further indirect cooling. Finally, the consistency of the end product can beformed to the desired extentunderthe influence of shearing forces.

The processes are performed in most cases in heatable and coolable vessels, in which counterrotating scrapers are used. It is a well known and widely used high-speed mixer, where the mixture is forced to pass through a relatively narrow space, thus ensuring proper heat transfer and excellent dispersing effect.

Continuous technology of grease production on Ca-, Na-, and Li-basis/see US-PS 3158 574/can be subdivided into three phases: the reactor, dehydrating and cooling phases. In the first sector of the pipe-equipment, operating at 1 500C and at a pressure of 27 kPa, the components according to the processes are fed at a speed ensuring a dwelling time of 5 minutes. The dehydrating unit operates at a pressure of 33 kPa, at 1900C. In the final sectorofthe cooler dwelling time is shorterthan one minute.

A process is also known, in the course of which saponification is performed at a pressure of 108,5 kPa, at 340 C. According to another continuous grease production process saponification is performed at room temperature in a mill. Here the oil component containing fatty acid and the Iyes pass between a grooved rotor rotating at a high speed and a stator, while reaction dispersion are taking place.

A heat-exchanger dispergator is also known, which consists essentially of two concentrically arranged cylinders. The heat transferring medium encloses the outer cylinder, while the inner performs a rotary motion and blades arranged on the surfaces remove the material from the wall of both cylinders, simultaneously a grinding effect is also exerted. By means ofthis equipment a most intensive heattransfer can be ensured.

A homogenizator is also known in which due to the high shearing effect on the rotary disc the components are decomposed to elementary particles and are mixed with each another.

Finally, when producing lubricating greases or lubricating liquids containing solid matters, in the first stage of the continuous operation the solid lubricating substance is ground in the presence of a grinding liquid in a vibro-mill. The suspension is mixed with the additives and the oil component in pipes equipped with a static agitator, thereafterthe grinding liquid is removed in the film-evaporator and re-cycled to the beginning of the process. Accordingly, with this process dispersion is performed in a separate unit, in the vibro-mill, while mixing of the suspension is performed in a separate equipment, in the static agitator.

In pipes suitable for the performance of said process containing the static mixing elements, material stream cross-sectionsare identical and serve for mixing the material only. Accordingly, in these static mixers the speed of the material streams is constant not enabling intensive mixing, which could ensure dispersion ofthe material. Forthis reason dispersion must be performed in the vibro-mill.

Summing up what has been said, in course ofthe previously mentioned processes dispersion is performed by means of a mechanical agitator, in a mill, while in the processes operated with dissipation heat transfer, solutions with scrapers are used.

The aim ofthe invention isto develop a process and equipment aimed atthe improvement of known processes, whereby while- simultaneously maintaining the advantages of continuous production mechanical mixing devices can be omitted, the number of the machines needed forthe performance ofthe process, investment costs and costs of operation can be considerably decreased, the operational process can be accelerated and by the use of which lubricating grease of equal quality can be produced.

Accordingly, the invention relates to the continuous production of lubricating greases, in course of which the mixture oil, glyceride andlorfatty acid and/or oxidized paraffin and/or oxy-fatty acid andlor other additives is dispersed and saponified, the reaction mixture thus obtained is dehydrated and/or desolvated, thereafter the resulting grease base is mixed in an equipment- performing heat-treatment and simultaneous agitating - if desired, by adding a further oil component and/orfurther additives, if desired simultaneously dispersed, thereafter cooled and homogenized.

The process according to the invention can be characterized in that the material stream of one or more components forming the starting mixture, in form of separate and/or combined- optionally preheated-stream, is streamed one or repeatedly in a reactor forming a static mixer, the dehydrated grease base is streaming with the oil component added thereto in the heat treating equipment forming a further static mixer; thereafter after having added further oil component and/or an additive if desired, the introduced material stream is streamed as one or more parallel co-currentstreams in the cooler also forming a static mixer-, while the speeds of the single material streams are alternatively changed continuously in an opposite sense; meanwhile, in the single phases of changing the speed, the media streaming - at least in two space-parts separated with a partition wall are brought into contact and one or more media are optionally brought in a streaming motion, by producing one or more streams and changing the direction of streaming, thereafter in the reactor- representing one ofthe static mixersdispersion and saponification, in the heat-treating equipment- holding the dehydrated grease base and recirculating the same once or repeatedly, at least partly-formation of the grease structure is performed, whereas in the cooler cooling ofthe grease, formation of consistency and homogenization takes place.

According to preferred performance of the process according to the invention in the static mixers, in one or more material streams thereof, at least in a part of the phase of changing the speed in opposite sense, a flow deviating from the axial direction ofthe main stream, in a given case an approximately rectangular stream is induced.

In accordance with the invention it is considered as advantageous, if in the static mixers the material stream deviating from the direction of the axial main stream and in an extreme case approximating the rectangular, is produced at the end ofthe phase of changing in the opposite sense and/or thereafter.

In addition to the direction of the main stream in an extreme case an approximately perpendicular radial streaming component can be produced so that the radial forced stream is caused by the curvature of the partition wall according to the invention.

Thus, in accordance with a preferred performance ofthe process according to the invention in the static mixer units the material stream is allowed to stream in a forced stream, deviating from the direction of the main flow, in an extreme case approximately perpen dicu larly, by means of the curvature of the partition wall(s) sub-dividing the space.

In course ofthe process according to the invention the material streams are brought into contact at the discontinuity of the partition wall separating them or therethrough. Inorderto be able to achieve an increased mixing effect a material flow streaming with an ever increasing speed is brought into contactwith one or more slower material streams, however, in any phase of changing the speed, acceleration or slowing down, a contact may be established between the faster material stream and the slower material stream.

In accordance with the invention in this case one can proceed so that in the static mixers, in the single phases of changing the speed the material streams are brought into contact by interrupting the partition wall separating the material streams.

In accordance with the process according to the invention quality resp. extent of saponification, cryastallization, dispersion, heating, cooling and homogenization can be improved, in so far as in the mixing units the material streams flowing parallel and separated by the partition walls are decomposed in parts at the discontinuities of the partition walls, by turning the edges of the partition walls facing the material flow, simultaneously or displaced in the direction of streaming.

According to another preferred embodimentofthe process according to the invention in the static mixers the edges of the partition walls following the discontinuity ofthe partition walls, facing the stream, are turned at an angle in relation ofthe end of the former partition walls, thus subdividing the parallel flowing material stream in parts.

The invention also relates to an equipmentforthe continuous production of lubricating greases, for performing the process according to the invention equipped with recipients for receiving the basic material, with agitating organs, dehydrating and/or desolvating devices, with a heated heat-treating equipment,aswellaswithacoolerand a homogenizer.

In this case the essence ofthe invention lies in that it has a heated saponifying reactor, an equipmentfor heat treatment, a cooler, as a separate static mixing unit each, with one or more confining walls and partition wall arranged in the inner space around the longitudinal axis; the partition walls ofthe saponifying reactor, the heat treating equipment and the cooler -thereafter static mixing unit-enclose at least partly alternating, an acute or obtuse angle with the longitudinal axis and/or with the pre-selected plane laid across the longitudinal axis or with the confining walls arranged around the longitudinal axis, they are and optionally arranged, as to form in direction of the longitudinal axis- at least partly alternating - spaces with widening or narrowing cross-sections.

It is considered as advantageous, if in the inside of the static mixing units partition walls are arranged, which are enclosing an acute or an obtuse angle with the longitudinal axis and/orwith some pre-selected plane laid across the longitudinal axis or with the confining walls around the longitudinal axis alterna tively.

According to afurtherpreferred embodimentofthe invention in the inside of the static mixing units partition wallsformed with discontinuities are arranged.

Advantageously, in the inside of the static mixing units partition walls of a helical shape arse arranged, which enclose alternatively an acute or an obtuse angle with the longitudinal axis and a continuously alternating angle with some pre-selected plane laid across the longitudinal axis.

According to a further preferred embodiment of the invention in the inside of the static mixing units partition walls following one another and twisted in the opposite direction are arranged.

According to another preferred embodiment ofthe invention in the inside of the static mixing units, following the end of some or every single partition wall there are further partitions-turned-off at a given angle-to be found.

It is also considered as advantageous, if the partition walls arranged in the inside of the static mixing units and enclosing at least partly alternatively acute or obtuse angle with the longitudinal axis and/or with any pre-selected plane laid across the longitudinal axis or with the confining wall around the longitudinal axis, are crossed with partition walls closing in itselves, enclosing an acute or obtuse angle in the opposite sense and forming a narrowing or a widening spatial part.

The main advantage of the invention is in that lubricating grease can be produced with a good productional efficiency and constant qualitative characteristics with a minimal requirement of machines and a minimal energy consumption.

The invention will be described in detail by means of preferred embodiments, wherein figures 1 to 14 illustrate the sectional view of the independentstatic mixing units applied in the saponifying reactor, in the heat-treating equipment, i.e. in the cooler of the equipment according to the invention, while figures 15 to 17 illustratetheschematical arrangementofthe equipment for producing lubricating grease, belonging to an example each of the embodiments according to the invention.

In figure 1 the partition wall 1 around the longitudinal axis has a circular cross-section, while the confining walls 2 enclose an acute or an obtuse angle with the longitudinal axis- alternatively e.g. with the direction of the arrow AB -. According to the embodiment shown here the angles indicated are complementary angles. The space-part I is narrowing in direction of the longitudinal axis, i.e. towards the arrowAB, while at the same time the space-part II is widening; the space-part lil confined with the confining wall 1 with the exclusively circular cross-section is of the same cross-section,thespace-part is widening towards the longitudinal axis, at the same time the space-part V is narrowing.Thus the space-part I and the following space-parts IV and VII, i.e. the space-parts ll-V-VIll and so on are alternatively narrowing orwidening, however, at the sametimethe space-parts I and II or IV and V etc. are also alternatively narrowing or widening.

According to another solution - representing one of the embodiments of the invention-the space-parts I, IV,VII etc. are alternatively narrowing and widening, while the cross-sections of the space-parts II,V, VIII etc. are always identical. The partition walls 2 accord ing to figure 1 can be considered as one single partition wall with a discontinuity on the places 5. In figure 1 the arrow A indicates the inflow of one of the material streams, the arrow B indicates the inflow of the other material stream, while the arrowAB indicates the mixed material stream leaving the equipment.

In figure 2the section C-Coffigure 1 can be seen; where within the confining wall 1 with the circular cross-section one single partition wall 2 is arranged, dividing the space into two parts. Figure 3 illustrates three partition walls 2 meeting atan angle, dividing the space within the confining wall 1 into three parts.

According to the embodiment which can be seen in figure 4six partition walls 2 meet in the axis, accordingly, the space within the confining wall 2 is divided in six space-parts.

According to the embodiments to be seen in fig. 5 and 6 the confining wall 1 has square cross-section, the partition walls 2,3,4 are of different length. The partition wall 3 reaches to the confining wall 1 and enables in such a mannerthe lateral introduction of the material stream B. Partition walls 2 and 4form a single continuous partition wall with the discontinuities 5. In figure 5 the discontinuity 5 is illustrated as a perforation or a hole covered with a sieve cloth.

In figures 7 and 8 an arrangement can be seen, wherein the partition wall 2 encloses alternatively an acute or an obtuse angle with some a-b plane laid across the longitudinal axis. In relation to said plane the partition waIls 2 form alternatively an acute or obtuse angle, at the same time they enclose with the longitudinal axis an acute or an obtuse angle. In figure 8 an extreme case of the previously described arrangement can be seen, wherein the arrangement according to the invention is realized by supposing that the selected a-b plane encloses an optional angle with the plane according to figure 8, and the partition walls 2 enclose alternatively an acute or an obtuse angle with the a-b plane. By rotating the a-b plane into the plane of figure 8, the half of the partition walls 2 encloses a right angle with the rotated a-b plane i.e.

they run perpendicularly thereto.

In figures 9 and 10 the partition walls 2 do not enclose an angle with one another butthey are coplanarly arranged. The partition walls 2 can be considered as one single partition wall 2 formed with the discontinuities 5. On the confining wall 1 - having a square cross-section with this embodiment-the narrowings are formed by the arched cutouts 6, i.e. by the angled and circular cutouts 6. Downstream the narrowings are forming first a narrowing, then a widening space with the partition wall 2.

In figure 11 the cross-section of the static mixing unit is shown subdivided into four space-parts by means ofthe partition walls 2 crossing each other in a perpendicular direction.

In figures 12 and 13the partition walls2 are helically arranged around the axis and enclose an angle therewith. The partition walls 2 enclose a continuously changing angle with the pre-selected a-b plane. The partition walls 2 following on another are twisted in an opposite direction, in relation to the end of every partition wall 2 the beginning ofthefollowing partition wall 2 is arranged so, as being twisted at a given angle.

The spatial cross-sections formed by the partition walls 2 are continuously changing in relation to each other.

As one can see in figure 14, the partition walls 7 self-closing and passing through the partition walls 2 arranged alternatively at an obtuse or acute angle are positioned at an acute or obtuse angle and form narrowing or widening space-parts.

In course ofthe operation ofthe static mixing units according to the invention neither the units northe elements thereof perform any motion. In general, at leasttwo material streams are allowed to stream through the units; however, these at least two material streams may be identical, they may differ in respect to physical character, e.g. to temperature, or in orderto achieve better mixing, they were halved in advance. The two material streams to be seen in the figure flow in direction of the arrows A and B into the separate space-parts ofthe static mixing units; at the end ofthe static mixing units they leave the system fully mixed, as the material stream AB.

The details of the process and the equipment according to the invention will be described in the following examples: Example 1 (Figure 15) Into the heatable recipient 11 equipped with the agitator 10 315.5 kg lubricant oil componentare added by means of a pump, the component is heated to 70 to 80 C, thereafter 6.6 kg Al-distereate, 55.2 kg stearic acid, as well 0.06 kg antifoam additives are added.

Simultaneously, in another recipient 13-which can be heated and which is provided with the agitator 12 1201 water are introduced; after heating to 70 C, under steady stirring 7.2 kg calcium hydroxide, kg sodium hydroxide and 60 kg calcium acetate are added.

From the recipients 11 and 13, with the pumps 14 and 15 respectively, in a proportion of 2: 1, at a total speed of 100 kg/h the suspensions thus prepared are continuously fed into the heatable reactor 16, wherein saponification takes place at 90 C. The leaving reac tion composite is led into the rotaryfilm-evaporator 17 with a surface of 1.3 m2 and with a mantle temperature of 1 600C, in the evaporator the water contained in the reaction composite is fully evaporated.

The anhydrous grease base discharged from the bottom ofthefilm-evaporator 17 is led continuously by means of a pump into the heat-treating equipment 18 provided with the static mixing elements; in the first sector of said equipment subsequently a mineral oil component is fed, into which additives were admixed in the necessary quantity.

With continuous feeding and constant recirculation, in the heat-treating equipment 18 the grease is subjected to a heat-treatment at 2200C. The grease quantity discharged from the heat-treating equipment is led continuously with a speed of 100 kg/hourintothe100kg/hour into the cooler 19 equipped with the static mixing elements, here the grease is cooled to 30-800C and continuously packed. Simultaneously with cooling, in the cooler 19 consistency ofthe grease is formed and homogeniza tion also takes place.

Example 2 (Figure 16) Into the heatable recipient 11 equipped with the agitator and formed as a duplicator 315 kg lubricating oil component are added by means of a pump, thereafter2.3 sodium hydroxide and 0.06 kg ) antifoam-agent- dissolved in 201 water- are added; after heating to 70-80 C 6.6 kg Al-distereate, 55.2 kg of stearic acid,7.2 calcium hydroxide and 60 kg calcium acetate are added.

With a steady recirculation by means of the pump 14, at a speed of 230 kg/h the suspension thus prepared is fed into the heatable reactor 16 provided with the static mixing elements, wherein at 90 C saponification takes place; the reaction mixture discharged is led to thefilm-evaporator 17 of a surface of 1.3 m2 and with a mantle temperature of 1 600C, wherein the water is evaporated from the grease base.

After-treatment of the grease is performed - after admixing the lubricating oil component containing the additives in the required quantity- in accordance with example 1.

Example3(Figure 17) From the recipients not illustrated here, into the first sector of pressurized pipe-reactor 20 provided with the static mixing elements, by means of a pump and with a speed of 180 kg/h lubricating oil component of the temperature 30-40'C is charged, while in the second sector at 90 C at a speed of 46 kg/h the melt of 12-hydroxy-stearicacid is charged. After heating the oil the 12-hydroxy-stearic acid is introduced to 90 C in the first and second tract ofthe pipe reactor 20, at the beginning of the third tract 40% aqueous lithium hydroxide solution are added at a speed of 23.4 kg/h.

In the last tract ofthe pipe-reactor 20 saponification takes place.

The reaction mixture is led into the heatable film-evaporator 17, therefrom water leaves in form of steam. The grease base discharged from the bottom of thefilm-evaporator 17 at a temperature of 160 C is led by means of a pump into the heatable heat-treating equipment 18 equipped with the static mixing elements. lntheheat-treatingequipmentl8,attheinflow of the grease base, from a storing recipient not illustrated here continuously 200 kg lubricating oil component/hour is also charged. In the heat-treating equipment 18 with a steady circulation and at a temperature of 180-21 00Cthe soap is dissovled in the oil. To the grease discharged from the heat-treating equipment 18 subsequently cold oil containing the additives in the necessary quantity in continuously added in a quantity of 430 kg/h; thereafter in the cooler 19 containing the static mixing elements the grease structure is formed, i.e. the grease is homogenized.

The grease-as a final product-is led from the cooler to the packing station not illustrated here.

Forfurtherdetails ofthe mixers, reference may be madeto British PatentApplications Nos. 8027293 and 8027294 (Publication Nos. 2057282 and 2056871).

Claims (22)

1. Process forthe continuous production of lubri cating greases in course ofwhich the mixture of oil, glycerideand/orfattyacid and/or oxidized paraffin and/or oxy-fatty acid and/or other additives is dis persed and saponified, the reaction mixture thus obtained is dehydrated and/or desolvated, thereafter the resulting grease base is mixed in a heat-treating and simultaneously mixing equipment, if desired by adding a further oil component and/orfurther addi tives, if desired, dispersed, cooled and homogenized, characterized in thatthe material stream of one or more components forming the starting mixture, in form of seperate and/or combined- optionally pre- heated stream, is allowed to stream once or repeatedly in a reactor forming a static mixer, the dehydrated grease base is streaming with the oil component added thereto in the heat-treating equipmentforming a further static mixer; thereafter, after adding further oil componentand/oran additive, if desired, the introduced material stream is allowed to stream as one or more parallel co-currentstreams in the cooler-also forming a static mixer-, while the speeds of the single material streams are alternatively changed continuously in an opposite sense; meanwhile in the single phases of changing the speed, the media streaming - at least in two space-parts separated with a partition wall -are brought into contact and one or more media are optionally brought in a streaming motion, by producing one or more streams and changing the direction of streaming, thereafter in the reactor- representing one ofthe static mixersdispersion and saponification, in the heat-treating equipment- holding the dehydrated grease base and recirculating the same once or repeatedly, at least partly-formation ofthe grease structure is performed, whereas in the cooler cooling ofthe grease, formation of consistency and homogenization takes place.

2. Process according to claim 1, characterized in that in the static mixers, in one or more material streams thereof, at least in a part of the phase of changing the speed in opposite sense, a flow deviating from the axial direction of the main stream, an approximately perpendicularstream is optionally induced.

3. Process according to claim 2, characterized in that in the static mixers the material stream deviating from the direction of the axial main stream and in an extreme case approximating the normal, is produced in the phase of changing in the opposite sense and/or thereafter.

4. Process as claimed in any of the claims 1 to 3, characterized in that in the static mixing units the material stream is allowed to stream in a forced stream deviating from the direction of the main flow, in an extreme case approximately perpendicularly, by means of the curvature of the partition wall(s) subdividing the space.

5. Process as claimed in any ofthe claims 1 to 4, characterized in that in the static mixing units in the single phases of changing the speed the material streams are brought into contact by the discontinuities ofthe partition walls dividing the spaces in parts.

6. Process as claimed in any of the claims 1 to 5, characterized in that in the mixing units the material streams flowing parallel and separated by the partition walls are decomposed in parts at the discontinuities ofthe partition walls, by turning the edges of the partition walls facing the material flow, simultaneously, or displaced in the direction of streaming.

7. Process as claimed in any of the claims 1 to 6, characterized in that in the static mixers the edges of the partition walls following the discontinuity of the partition walls, facing the stream, are turned at an angle in relation to the end of the former partition walls, thus subdividing the parallel flowing material stream in parts.

8. Equipmentforthe continuous producion of lubricating greases, for performing the process according to any of the claims 1 to 7, equipped with recipients for receiving the basic material, with stirring organs, dehydrating and/ordesolvating devices, with a heated heat-treating equipment, as well as with a cooler and a homogenizer, characterized in that it has a heated saponifying reactor/1 6,20/, a heat-treating equipment/18/, a cooler/19/, as separate static mixing unit each, with one or more confining walls/1/ and partition wall /2/arranged in the inner space around the longitudinal axis; the partition walls/2/ofthe saponifying reactor/1 6/, the heat-treating equipment /18/and the cooler/1 9/-thereafter static mixing unitenclose at least partly alternating, an acute or obtuse angle with the longitudinal axis and/orwith the pre-selected plane/a-b/laid across the longitudinal axis or with the confining wal Is 111 arranged around the longitudinal axis, they are optionally arranged as to form in direction ofthe longitudinal axis-at least partly alternating -spacesll-VIll/with widening or narrowing cross-sections.

9. Equipment as claimed in claim 8, characterized in that in the inside of the static mixing units partition walls /2,3,4/are arranged, which enclose alternatively an acute or an obtuse angle with the longitudinal axis and/or with some pre-selected plane/a-b/been laid across the longitudinal axisand/orwith the confining wallsll/around the longitudinal axis.

10. Equipment as claimed in claim 8 or 9, characterized in thet in the inside ofthe static mixing units partition walls/2/formed with discontinuities 151 are arranged.

11. Equipment as claimed in any of the claims 8 to 10, characterized in that in the static mixing units helically shaped partition walls/2/ are arranged, which enclose alternatively an acute or an obtuse angle with the longitudinal axis and a continuously alternating angle with some pre-selected plane/a-b/ having been laid across the longitudinal axis.

12. Equipment as claimed in claim 11, characterized in that in the static mixing units partition walls /2/ following one another and twisted in the opposite direction are arranged.

13. Equipment as claimed in any of the claims 8 to 13, characterized in that following the end of some or every single partition wall /2/there are further partition walls/2/-turned-offata given angle-.

14. Equipment as claimed in anyoftheclaims8to 13, characterized in that in the inside ofthe static mixing units partition walls /7/partly closing in itselves and confining a separate space-part are arranged.

15. Equipment as claimed in claim 14,characterized in that the partition walls /2/ arranged in the inside of the static mixing units and enclosing at least partly alternatively an acute or obtuse angle with the longitudinal axis and/orwith any pre-selected plane /a-b/ laid across the longitudinal axis or with the confining wall /1/around the longitudinal axis, are crossed with partition walls /7/closing in itselves, enclosing an acute or obtuse angle in the opposite sense and forming a narrowing orwidening spatial part.

16. A process of making grease which comprises either performing saponification in an oil medium and dehydrating and/or desolvating the saponification reaction product or mixing a pre-formed soap in an oil medium, heattreating and homogenising the grease base thus obtained, optionally having added further oil and other additives, and cooling the resulting grease, wherein the saponification step and/orthe heattreating and homogenising step and/orthe cooling step is performed by feeding component(s) in two or more streams into a duct, passing a first stream into a tapering orflaring chamberthereby accelerating or decelerating (respectively) that stream relative to a second stream, contacting the first and second stream when they have unequal flow velocities and repeating the said passing and contacting steps.

17. An apparatus for producing grease, the appar- atus comprising a heat-treatment device in fluid communication with a cooling device optionally together with a saponification reactor in fluid communication with, and up-stream of, the heat treatment device, wherein the heat-treatment device and/or the cooling device and/orthe saponification reactor (when provided) each comprise a duct containing a series of sequentially-arranged separation walls, each of which divides a length of the duct into a first chamberthatflares ortapers in an axial direction and a second chamber extending alongside the first cham ber,the shape of each pair offirst and second chambers being such that, in operation, fluid flowing throughthefirstchamber is accelerated or decelerated relative to fluid flowing through thesecond chamber, and wherein a discontinuity is provided between adjacent separation walls that allows fluid from the first and/or second chamber to flow therethrough.

18. A process substantially as hereinbefore de scribed with reference to any one of Figures 1 to 17.

19. A process substantially as hereinbefore described in any one of Examples 1 to 3.

20. Apparatusasclaimed in claim 17, which includes a saponification reactor and/or a heattreatment device and/or a cooling device substantially as hereinbefore described with reference to, and as illustrated in, any one of Figures 1 to 14 ofthe accompanying drawings.

21. An apparatus substantially as hereinbefore described with reference to, and as illustrated in, any one of Figures 15 to 17 of the accompanying drawings.

22. Grease produced by a process as claimed in anyoneofclaimslto7,16,18or19.