WO2000010398A1

WO2000010398A1 - Gut cleaning method and device for removal of fat or other floating substances

Info

Publication number: WO2000010398A1
Application number: PCT/SE1999/001332
Authority: WO
Inventors: Christer Appelgren
Original assignee: Ingenjörsfirman Geotech AB
Priority date: 1998-08-03
Filing date: 1999-08-03
Publication date: 2000-03-02
Also published as: EP1124429A1; SE510882C2; SE9802656D0; AU5662499A; SE9802656L

Abstract

The invention concerns a method of removing, in a casing factory, a substance (21) floating on a liquid (3). The surface (A) of the liquid is sprayed with a fluid in the form of jets (20) which are discharged in the direction of advancement of the guts and which form an acute angle (ζ) with the liquid surface (A). The substance (21) is thereby set in motion by the fluid and is transported in parallel with the liquid surface (A) crosswise relative to the direction of advancement of the guts and flows over edges (8) adjacent the walls (2b) of the container (2). The invention also concerns a device for implementing the method, consisting of a fluid feeding means in the form of a pipe (5) arranged crosswise relative to the direction of advancement of the guts. The pipe is provided with several apertures (5), through which the fluid may be discharged in the form of jets (20).

Description

GUT CLEANING METHOD AND DEVICE FOR REMOVAL OF FAT OR OTHER FLOATING SUBSTANCES

Technical Field

The present invention relates to a method used in a casing factory, wherein guts are advanced through a liquid inside a container, of removing substances, particularly fat floating on top of the liquid, rendering the cleaning process difficult, when the guts become greasy. The invention likewise concerns a device for performing the method.

Technical Background

Machines used in a casing factory require considerable amounts of flowing heated water. Water temperatures of 40-45°C are necessary to carry out the cleaning process and to prevent fat remaining inside the guts from solidifying.

The guts are fed into and are squeezed between two rotating rollers, while water is being sprayed in between the rollers, preventing the guts from sticking. After having been cleaned, the guts are drawn to a soaking tank, and the flowing water contributes to carry the guts down into the tank. Thereafter, the guts are transported at a slow pace through the water in the tank and are then processed by the next machine in the line.

The water in the soaking tank becomes very greasy and is removed directly by way of a discharge pipe, to be cleaned. The costs of cleaning this fat- laden water are considerable, and to these costs are added those of heating the large amounts of water consumed by the machine .

To remove the fat from the soaking tank by mechanical means, for example by using bottom or surface scrapers is not advisable, since the guts present inside the tank could become entangled and be damaged .

Summary of the Invention

The object of the present invention is to solve the above problems by means of a method and a device enabling separation of fat or other substances from the water in the soaking tank, making the water reusable thereafter to a very large extent.

This object is achieved by means of a method and a device as defined in the independent claims 1 and 5.

In accordance with the method of the invention a fluid in the form of jets is sprayed onto the surface of the liquid. The substance is thus set in motion by the fluid and is entrained thereby in parallel with the liquid surface and flows over at least one edge at the walls that delimit the container.

In other words, the jets of fluid transfer kinetic energy to the surface layer of the liquid and to substances floating thereon. The substances are set in motion and may be removed from the container in any suitable manner. The method of transferring kinetic energy by means of jets of fluid means that the risks of damages to the guts present inside the container have been removed. Since the cleaning process continuously requires considerable amounts of flowing heated water, the jets of fluid could quite simply form part of this flow, and consequently the method requires only very minor process-technical changes. The substance entrained by the fluid could also be transported crosswise relative to the direction of advancement of the guts along the liquid surface towards at least one of the sides of the container that extends in parallel with the direction of advancement of the guts. The movements of the fluid and of the substance are thus affected to allow removal of the substance at the container sides. This arrangement makes it possible to provide a number of substance discharge points, located downstream relative to one another, along the container sides. For instance, the substance may be caused to escape through at least one opening formed in the walls of the container. If the opening is located at a level spaced only slightly above the liquid surface, the substance may be made to collect at the opening and "climb" over the lower edge of the opening. This substance discharge method requires only very minor changes to be made to existing containers.

The fluid that is sprayed onto the surface may also consist of recirculated liquid withdrawn from the container and subjected to filtering in order to remove non-floating particles. In this manner water from which fat or other substances have been removed is made use of in the continued cleaning process. The device in accordance with the invention is provided with a fluid feeding means arranged to feed a fluid in the form of jets down onto the substance floating on top of the liquid and to cause the fluid to entrain the substance in a direction in parallel with the liquid surface to a substance discharge means located at the container walls.

The fluid feeding means could consists of a pipe extending crosswise relative to the direction of advancement of the guts and provided with several apertures through which the fluid may be discharged in the form of jets.

In addition, guide baffles may be arranged crosswise relative to the direction of advancement of the guts in order to guide the fluid-entrained substance towards at least one of the container walls that extends in parallel with the direction of advancement of the guts. The guide baffle may be bent at an angle directed towards said fluid feeding means so as to form a double plough share in the liquid, in the direction of advancement of the guts.

The container walls may comprise at least one aperture through which the substance may be discharged.

Brief Description of the Drawings

One preferred embodiment of the invention will be described in the following with reference to the accompanying drawings, wherein

Fig 1 is a perspective view of a soaking tank equipped with the device in accordance with one embodiment of the invention. Fig 2 is a plan view of the tank of Fig 1.

Fig 3 schematically represents a system of recirculation of water from the soaking tank. Description of a Preferred Embodiment

In the embodiment shown in Figs 1 and 2 and described in the following the device in accordance with the invention is arranged in a gut-cleaning soaking tank. The soaking tank, generally designated by reference 1, essentially consists of a rectangular container 2 made from stainless steel or plastics. When in use, the container is filled with liquid, usually water 3, up to a level A. A feeder 22 slowly advances guts 23 forwards through the water.

A fluid feeding means in the form of a pipe 4, preferably made from metal or rigid plastics, extends transversely across the container 2. In accordance with the shown embodiment, the pipe 4 is disposed along one of the short sides 2a of the container and the pipe length essentially equals the width of the container 2. The pipe 4 is formed with apertures equidistantly spaced along the entire length of the pipe 4. In accordance with the shown example, the apertures are minute holes 5, preferably having a diameter less than 5 mm, but could equally well conists of nozzles or nipples.

Two guide baffles 6, partly submerged into the water 3, are disposed between the two long sides 2b of the container, so as to extend across the entire container width. The guide baffles 6 suitably are made from e.g. stainless steel, and in accordance with the shown embodiment they are bent into a V- shape, the apex 6a of the V pointing towards the apertured pipe

4. Consequently, each guide baffle 6 forms a stationarily mounted, double plough share, which faces the apertured pipe 4 and which is partly submerged below the water level A.

Beginning at the attachment points 7 of the respective guide baffles 6 in the container long sides 2b and extending in the direction towards the apertured pipe 5, openings, in accordance with the shown example in the form of elongate rectangular slots 8, have been made in said container long sides at a level somewhat above and in parallel with the water level.

In summary, the slots 8 are located oppositely one another in pairs in opposed long sides 2b, and a guide baffle 6 configured as a plough blade extends between each pair of slots. The guide baffles 6 project above the upper edges 8a of the respective slots 8.

Ducts 9 extend externally along the long sides 2b of the container for the purpose of removing substances 21, such as fat, that are discharged through the slots 8. The ducts 9 slope downwards, in the direction away from the pipe 4.

For exemplifying purposes, Fig 3 illustrates how the device in accordance with the invention may be incorporated into a system of recirculation of water in a soaking tank. At the remote part of the tank as seen from the apertured pipe 4 an outlet pipe 10 is located, in which a pump 11 is arranged to remove cleaned water from the container 2. The outlet pipe 10 is located downstream from the two guide baffles 6, where the amount of remaining substances is minimal.

A filter 12 is positioned after the pump 11 for further cleaning of the water, as well as several pipes 13, 14, 15, and 16 carrying the cleaned water further. Pipe 13 carries water back to the soaking tank and divides into pipes 14 and 15, which carry water to the fluid feeding means 4 and directly to the container 2, respectively. Pipe 16 leads to another, water-consuming machine 17, and from there to a waste cleaning plant 18.

The mode of operation of the device will now be described.

A fluid is fed through the pipe 15 to the apertured pipe 4 and is forced out through the apertures 5 therein in such a manner that jets 20 are formed, which are sprayed downwards onto the liquid 3 in the container 2. In accordance with the shown example the fluid, like the liquid inside the container, consists of water and it is sprayed in the direction of advancement of the guts. The jets 20 are directed essentially tangentially against the water level A in the container, such that along the line of impingement they form a preferably acute angle φ to the plane of the water level A. The water jets 20 cause sustances 21 present on the surface to move in the direction of flow of the jets 20 along the surface A.

The substances 21, which primarily consist of fat, are moved into abutment against the transverse guide baffles 6 and are directed by said baffles against the two long sides 2b of the container 2 and collect in the area of the slots 8.

As increasing amounts of fat gradually collect adjacent the slots 8, the fat "climbs" up the sides of the container 2 and eventually flows out through the slots, the latter being positioned at a level only spaced a small distance, preferably one or a few millimeters, above the water level A. The fat then is collected in the ducts 9 extending externally along the sides 2b of the container, and is processed in any suitable manner. Downstream from the two guide baffles 6 water is pumped to the filter 12, where remaining pollutants are separated out by filtration, and the water may then be recirculated to the cleaning process.

In accordance with a preferred embodiment of water re-cirkulation a smaller amount of the cleaned water, preferably about 20%, is pumped to the waste cleaning plant 18 after having been used in a waste grinder 17 or other machine not requiring fully cleaned water, whereas a major proportion, preferably about 80%, is pumped back to the soaking tank 1. A proportion of the thus returned water, preferably about a fourth (i.e. approximately 20% of the original, cleaned water), is carried to the apertured pipe 4, which does not require any further water source. The remainder is fed into the container 2 together with fresh, heated water in an amount corresponding to the amount that is pumped to the waste cleaning plant 18.

In order to maintain the desired temperature level inside the container 2, the temperature of the freshly added water is higher than the desired water- temperature level in the tank. For example, the freshly supplied water may have a temperature of approximately 50 °C, in case the desired water temperature level in the tank is 40 - 45 °C.

The described embodiment may be varied within the scope of the appended claims. For example, it is not necessary that the walls 2b of the container 2 are formed with openings 8 designed for removal of the substance 21 but instead the latter may be removed by flowing over the upper edge of the container 2.

Alternatively, the container 2 could be formed with double walls, in which case the substance 21 is made to flow over the inner container wall.

In contrast to the described case, the fluid feeding device 4 could be arranged to discharge jets transversely across the direction of gut advancement. Alternatively, the fluid could be fed from below towards the surface of the liquid in order thus to achieve a similar effect.

The fluid, which in the described example is a liquid, could instead be a gas, for example air, which is propelled under pressure.

The configuration and the number of the components incorporated in the inventive object could be varied. For example, two or several fluid feeding means could cooperate to provide efficient discharge of fat. The guide baffles 6 could be straight instead of being V-shaped.

Claims

1. A method, used in a casing factory, wherein guts are advanced through a liquid (3) inside a container (2), for removing a substance (21) floating on top of the liquid, characterised by spraying the surface (A) of the liquid with a fluid in the form of jets (20) in such a manner that the substance (21) is set in motion by the fluid (20) and is entrained thereby in parallel with the liquid surface and flows over at least one edge at the walls (2b) that delimit the container.

2. A method as claimed in claim 1, characterised in that the substance (21) entrained by the fluid (20) is transported crosswise relative to the direction of advancement of the guts along the liquid surface towards at least one of the walls (2b) of the container (2) that extends in parallel with the direction of advancement of the guts.

3. A method as claimed in claim 1 or 2 , characterised in that the substance (21) is caused to escape through at least one opening (8) formed in the walls (2b) of the container (2) .

4. A method as claimed in claims 1 - 3, characterised in that the fluid (20) consists of recirculated liquid withdrawn from the container

(2) and subjected to filtering in order to remove non- floating particles.

5. A device for removal of a substance floating on the surface of a liquid (3) in a container (2) in a casing factory, in which container (2) guts (23) are advanced through the liquid, charact - e r i s e d by a fluid feeding means (4) arranged to feed a fluid in the form of jets (20) down onto the substance (21) floating on top of the liquid and to cause the fluid to entrain the substance (21) in a direction in parallel with the liquid surface (A) to a substance discharge means (8) located at the container walls (2b) .

6. A device as claimed in claim 5, characterised in that said fluid feeding means (4) is a pipe (5) extending crosswise relative to the direction of advancement of the guts and provided with several apertures (5) through which the fluid is dischargeable in the form of jets (20) .

7. A device as claimed in claim 5 or 6 , characterised in that the fluid consists of recirculated liquid, which has been withdrawn from the container (2) and filtered for removal therefrom of non-floating particles.

8. A device as claimed in claims 5 - 7, characterised by at least one guide baffle (6) arranged crosswise relative to the direction of advancement of the fluid in order to guide the fluid- entrained substance (21) towards at least one of the walls (2b) of the container (2) that extends in parallel with the direction of advancement of the guts.

9. A device as claimed in claim 8, characterised in that the guide baffle (6) is bent at an angle (6a) which is directed towards said fluid feeding means (4) so as to form a double plough share in the liquid in the direction of advancement of the guts.

10. A device as claimed in claim 9, characterised in that at least one of the walls (2b) of the container (2) is formed with at least one opening (8) through which the substance (21) may be discharged.