WO1982002674A1

WO1982002674A1 - Entrainment separator

Info

Publication number: WO1982002674A1
Application number: PCT/AU1982/000014
Authority: WO
Inventors: Creek Sugar Milling Ltd Cattle
Original assignee: Henderson Christopher Stuart; Horniblow Eric Lindsay; Pape Alan Fredrick; Hellmuth Barry John
Priority date: 1981-02-12
Filing date: 1982-02-12
Publication date: 1982-08-19
Also published as: EP0070864A1; JPS58500433A

Abstract

An entrainment separator suitable for separating droplets of a sugar liquid or the like entrained in a vapour. The separator includes a plurality of blades forming a circuituous flow path whereby liquid droplets coalesce on the blades.

Description

ENTRAINMENT SEPARATOR THIS INVENTION relates to separators, in particular- but not exclusively, for use in the sugar industry wherein it is required to separate entrained sugar juices and liquors being evaporated by either evaporators or vacuum pans in sugar factories or refineries.

While the separators of the present invention will hereinafter be described in relation to use in the sugar industry, it will be appreciated that it may be utilized in other applications and hence the invention should not be limited to this example application.

In sugar factories or refineries, sugar juice or liquor boiling in an evaporator (or massecuite in a vacuum pan) is splashed into the head space of a vessel by the boiling action imparted to the sugar juice, syrup or massecuite wherein it is held in suspension and carried over tθ' a contact condensor by^* the high velocities of the evaporated water vapour (boiling is conducted at about 24 to 26 inches of mercury} . If this process is allowed to continue unchecked, there is a resultant loss of sugar which is far too excessive for economic sugar production in sugar factor¬ ies or refineries . In the past entrainment separators have been used to extract entrained sugar in the vapours from evaporators and vacuum pans and the like. However the separators utilised to date have been either inefficient in use or costly to install.

Many types of separators have been tried in the sugar refining industry, however vapour velocities encountered in evaporators and vacuum pans are considerably higher than those in most other applications with the result that conventional separators do not work efficiently in the sugar industry in particular.

' It is therefore an object of this invention to provide an entrainment separator suitable for use in

- sugar factories or refineries or elsewhere which, facilitates the separation of entrained liquid from a vapour. In one aspect this invention aims to provide an entrainment separator for the sugar refining industry wherein entrained sugar liquid may be removed by the separator and returned to the evaporator. It is also an object of this invention to provide an entrainment separator which will be of a form which is economical to manufacture and reliable and efficient in use. Other objects and advantages of this invention will hereinafter become apparent.

With the foregoing and other objects in view, this invention in one aspect resides broadly in a separator for separating liquid from a. fluid, said separator including a blade assembly adapted to be disposed in a fluid flow and providing a plurality of fluid contacting faces arranged to cause said fluid to flow circuituously across or through said blade assembly whereby liquid entrained in said fluid will coalesce on said fluid contacting faces.

Suitably the contacting faces are substantially uprig -t in use when installed in an evaporator vessel or in a vacuum pan. The blade assembly may be attached in a desired location within the evaporator vessel or vacuum pan and is so constructed and arranged that the vapour entrained with sugar liquid follows a tortuous or twisting path past or through the plurality of fluid contacting faces. Because of the constant changes in direction associated with the construction of the blade assembly, the entrained sugar liquid will gather or coalesce on the faces exposed to the vapour flow and may be returned to the evaporator or vacuum pan by any suitable means.

Each blade assembly suitably has a cross sectional profile that is discontinuous and thus nay adopt a substantially zig-zag or sawtooth shaped profile. If desired the cross sectional profile may be sinusoidal or adopt a -wave form shaped profile. Preferably however, a sawtooth shaped profile is used with the leading face of the blade assembly exposed to the vapour flow^* being located inclined to the longitudinal direction of the vapour flow such as by being located at 45 to the said longitudinal direction. The next exposed face may then be located at 9.0 to _the plane of the first exposed face and in effect be providing a second exposed face at the opposite side thereof at 45 to the direction of vapour flow. There may then be provided a third and fourth exposed face of similar shape to the first and second exposed faces, and even a fifth and sixth exposed face of similar shape to the first and second exposed faces. At each change of direction of each blade there is suitably provided a discontinuity adapted to cause turbulence in the vapour flow and prevent tracking of the fast moving vapour and entrained liquid between the blades without separation of the liquid by impingment against the respective blade surfaces. Because of the constant changes in direction with regard to the multiplicity of exposed faces associated with a single blade assembly, then it will be appreciated that the sugar liquid associated with the water vapour will coalesce on the said exposed faces of the blade. However, suitably there is provided a plurality or bank of blade assemblies each suitably having a cross sectional profile as described. Any appropriate number of blade assemblies may be used with a suitable number being eight. The liquid after contacting the exposed faces of the blade assemblies may then fall to the bottom of the substantially upright blades where the velocity of the water vapour impinging on the exposed faces of the bank of blades may seep or draw the sugar liquid out onto a sloping baffle which leads to a drain returning the separated sugar liquid to the evaporator or vacuum pan.

There also may be provided a suitable support frame for the bank, of blades and this may comprise a plurality of bottom frame members which are provided with upwardly extending cleats having a base flange bolted to the frame members. Each frame member may itself be bolted to a support platform or partition located in the head space of the evaporator or vacuum pan.

In order that the invention may be more readily understood and put into practical effect, reference is now made to preferred embodiments of the invention as shown in the attached drawings wherein:-

FIG 1 is a perspective view of one form of entrainment separator constructed in accordance with the invention with the top blade attachments removed for clarity;

FIG 2 is a top plan view of the separator of FIG 1 attached to an eliminator vessel or vacuum pan vessel; FIG 3 is an end view of the lower portion of the apparatus of FIG 2 in the direction of the vapour flow;

FIG 4 is a side view of the apparatus of FIG 2 taken in the direction A;

FIG 5 is a schematic diagram showing the separator of FIG 1 attached to an evaporator vessel; and;

FIG 6 is a schematic diagram of the separator of FIG 1 attached to a vacuum pan.

In the drawings, the separator 10 includes a plurality or bank of blades 11 having faces 12, 12A, 15,

15A, 16, 16A and 17 as shown in FIG 2 which are exposed to the fluid flow. The bank of blades 11 are supported on base frame members 20 and are attached thereto by cleats 19 and 19A and bolts 21. The frame members 20 are supported on a partition 23 of the eliminator vessel and are attached to the side wall 2& of the circular vessel by attachment member 24 which has flanges 27 attached to the wall 26. Bolts 22 also attach the separator assembly to partition 23 as shown. Angle iron brackets 25 also assists in the attachment of the support member 20 to partition 23 as shown in FIG 4. Brackets 25 interconnect member 24 to the separator 10 as shown in FIG 2.

It will be seen that each blade 11 includes flow interruption means 30, extending outwardly into the fluid flow path from the junction between respective faces of the blades 11. Each flow interruption means in this embodiment is in the form of continuation portion 7 of the trailing end of the exposed face. Each continuation portion 7 extends substantially at right-angles to the direction of fluid flow. The continuation portion 7 extends between the trailing end 9 of an exposed face and the leading end 8 of the adjacent exposed face at the opposite side of the blade 11. This arrangement provides a blade whic can be easily formed from sheet metal or the like such as by folding , roll-forming or pressing. Furthermore, it will be seen that the flow interruption means 30 in adjacent blades are substantially in register in the direction of fluid flow into the separator 10 whereby a direct flow path from one side of the separator to the other is prevented.

In use, as fluid flows through the separator it will be deflected along a zig-zag path between spaced faces of adjacent blades 11. As the fluid flow changes direction through ninety degrees from one leg of the flow path to the next leg it impinges against the flow interrup¬ tion means 30 which deflects a portion of the flow laterally. The sudden change in direction of the flow causes increased impingment against the blades 11 and increased liquid separation and deposit on the blades. It is believed that the deflection of a portion of the flow by the interruption means 3Q causes turbulence in the flow particularly adjacent the change in direction of the body of flow between respective adjacent legs and this turbulence prevents tracking of the fast moving liquid between blades and ensures the necessary impingment between the liquid and the faces of the blades which result in separation of the liquid from the gasses..

As shown in FIG 5, the entrainment separator 10, is suitably arranged in a vertically extending outlet opening 31 provided in the upper portion of an evaporation housing 32. The outlet 31 extends between a first ceiling member 33 which extends part way across the housing 32 and a second ceiling member 34 spaced downwardly from, the first ceiling member 33 and extending across the remainder of the housing 32. This arrangment provides a flow path for vapour from the boiling juices contained in the evaporator and which extends upwardly and then passes substantially horizontally through the entrainment separator 10 and along the lower ceiling portion 34. The vapour then passes upwardly from the housing 32 through a conduit 35 to be conveyed for further treatment as desired. Since the blades of the entrainment separator 10 are disposed vertically, the vapour and entrained droplets pass through the separator and are subject to a number of sudden changes of direction which causes the liquid droplets to impinge on the blade surfaces where they accumulate. As they coalesce,the liquid drains to the bottom of the entrainment separator 10 where the accumulated liquid is swept out by the vapour flow, and in the same direction, towards the draining baffle 36. At this stage, the vapour velocity is reduced while the direction of flow is altered upwards and away from the liquid flow towards the baffle thus alleviating the possibility of re-entrainment of the separated liquid. The liquid which accumulates at the baffle 36 flows gravitationally through the drain 38 back to the boiling juices 37. This arrangement ensures that at no stage is the separated liquid forced to flow against the direction of the vapour flow so that re- entrainment is effectively prevented. FIG 6 illustrated a further embodiment of the invention adapted for use with a vacuum pan apparatus. As will be seen in this embodiment the principal of operation is substantially the same as the embodiment described in FIG 5. However in this embodiment the separated liquid flows from the entrainment separator 10 down the inclined roof portion of the vacuum tank 40 to return drains 41 located exteriorally of the vacuum tank 40

If desired each blade assembly could be constituted of a plurality of louvre type blades spaced from one another and of course the arrangement of the blades could be such that they are aligned in the direction of flow or staggered or otherwise arranged as desired.

Of course, while the above has been given by way of illustrative example of the invention, all such modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as is defined in the appended claims.

Claims

1. A separator for separating liquid from a fluid, said separator including a blade assembly adapted to be disposed in a fluid flow and providing a plurality of fluid contacting faces arranged to cause said fluid to flow circuituously across or through said blade assembly

• whereby liquid entrained^' in said fluid will coalesce on said fluid contacting faces.

2. A separator according to claim one, wherein said blade assembly is in the form of a continuous panel having a plurality of faces each arranged angularly to the adjacent faces.

3. A separator according to claim 2, wherein there are provided a plurality of said continuous panels arranged in spaced face to face relationship with the peaks between adjacent faces of each panel disposed between the spaces between the peaks of an adjacent panel.

4. A separator according to claim 2 or claim 3, wherein said faces in each said panel are planar.

5. A separator according to claim 4 , wherein said planar faces in each said panel extend substantially at right-angles to one another.

6. A separator according to any one of claims 1 to 5, wherein there is provided flow interruption means operatively associated with the, or each side blade assembly and adapted to create a zone or zones of turbulence in said fluid flow.

7. A separator according to claim 6, wherein said flow interruption means is constituted by a projec¬ tion extending outwardly from one or more of said fluid contacting faces.

8. A separator according to claim 7, wherein said projections extend outwardly substantially at right- angles to the direction of fluid flow.

9.. A separator according to any one of claims

2 to 8, wherein each said panel assembly is of a form whereby it may be pressed, bent or roll-formed from sheet material.

10. A separator according to any one of claims 6 to 9, wherein said projections of each said blade assembly lie in register with the projections of an adjacent blade assembly.

11. An evaporator assembly including a housing for containing boiling juices said housing having a fluid flow outlet for the passage of vapours from the said boiling juices and there being provided an entrainment separator in said fluid flow outlet, said entrainment separator being as defined in any one of the preceeding claims and drain means for-collecting liquids from said entrainment separator.

12. _. An evaporator assembly according to claim 11, ^■ wherein said blade assemblies extend vertically across said outlet and said drain means carries the liquids away from said entrainment separator for return to said boiling juices.

13. An evaporator assembly according to claim 12, wherein said drain assembly is so made and arranged that the fluid flow beyond said entrainment separator assists movement of said liquid in said drain operatively towards said boiling juices.

14. An evaporator or vacuum pan assembly substantially as hereinbefore described with reference to the accompanying drawings,

,

15. A separator substantially as hereinbefore described with reference to the accompanying drawings.