WO2002074458A1

WO2002074458A1 - Scraper

Info

Publication number: WO2002074458A1
Application number: PCT/DE2002/000774
Authority: WO
Inventors: Joachim Paul; Ernst Jahn
Original assignee: Integral Energietechnik Gmbh
Priority date: 2001-03-16
Filing date: 2002-03-05
Publication date: 2002-09-26
Also published as: EP1368139A1; DE10113395C1

Abstract

The invention relates to a scraper having a self-supporting form with a central section (18), comprising a first section (10) provided with a scraping edge (A), second and third sections (12, 14) provided on the central section (18), which is supported by a support device (22) and which essentially encompasses the support device (22). Both of said sections (12, 14) together with a bearing surface of the control section which joins them, are formed with an approximately cylindrical inner surface. Said inner surface runs parallel to the extension of the scraper, whereby the scraper is disposed in a rotatable manner about an axis parallel to the extension thereof on the corresponding support device (22) which is formed in a rotationally symmetrical manner, at least in the supporting area. A fourth section (16) is arranged on a supporting surface (26) which is essentially parallel to the surface to be scraped, in a spring actuated manner, pressing against the scraper (32), rotating it around the support device until the edge (A) comes to rest in close proximity against the surface (24) which is to be scraped.

Description

scraper

The invention relates to a scraper, i. H. a device that serves to remove a substance - hereinafter referred to as a product - from a surface or to prevent "product" from settling or adhering to the surface permanently.

The product can be a pure substance or a mixture of different substances. It can either be a solid, a liquid or a pasty mass, which is composed of a fluid, i.e. H. a substance in which the "product" is contained. The fluid can be liquid, gaseous or possibly also multi-phase.

There are now numerous processes in industry in which a surface comes into contact with a product or products or with components thereof, which have to be removed from this surface or whose adhesion to the surface has to be avoided.

Such processes are, for example, the crystallization by heating or cooling a fluid, the evaporation (eg under vacuum conditions) of components of a fluid, the wanted or unwanted contamination of the surface by adhering product or fluid components in solid or liquid or also pasty form (e.g. soot, slime) etc.

In all of these cases, the surface is continuously or discontinuously in regular, irregular be freed from product build-up regularly, especially at intervals according to requirements.

This is done by using a scraper that keeps the surface free of products and product components. So far, the scrapers have been produced in a geometrically strictly defined manner, in which an edge runs in connection with an equally strictly defined surface, for example a drum wall. Such a configuration ensures that the scraper and surface are always in the desired engagement, and a forceful effect can also be added by spring tension. Strictly geometric configurations are usually complex and therefore expensive.

Furthermore, it is also possible to use a casual geometrical configuration in which the surface or scraper are arranged geometrically "casually" within a tolerance limit and dimensional deviations have to be recorded by the scraper system. It can be less a form-fitting, but above all a force-fitting effect, which is brought about, for example, by centrifugal forces, spring forces or the like.

Such casual configurations are simpler and therefore cheaper to manufacture, but more risky to operate because e.g. the necessary centrifugal or spring forces must always be built up identically and under certain operating conditions are not sufficient to apply the high forces to detach the product.

Finally, geometrically undefined, flexible configurations are also conceivable, in which the normally rigid surface is acted upon by a scraper which is geometrically undefined. Here comes one non-positive and liquid state effect, whereby the scraper may be a little stiff to match the geometry of ^¬. Examples of this are brushes that can adapt to a surface in an undefined configuration. However, brushes are rarely used because they can clog with the product and other fluid partners and are difficult to clean.

Reactors for mixing substances are known from DE-A1 41 25 629, DE-A1 37 41 653, DE-B2 20 47 366, US 5 009 510, US 4 095 307 and JP 091 03 666. which are equipped with mixing and shear organs.

The invention has set itself the task of improving a casual geometric configuration so that it is hardly affected by geometric deviations, especially in the direction perpendicular to the surface to be scraped.

Furthermore, the adhering product should be permanently removed from the surface and a resilient effect of the scraper should be achieved without additional equipment.

According to the invention, this is solved by the features of the main claim. The subclaims represent advantageous embodiments of the invention.

In particular, it is advantageous that the scraper is mounted on a rotating edge for receiving a supporting force in such a way that the scraper section's driving section, which is provided with a strong cross-section, transmits the scraper driving forces almost at right angles to the scraper edge, without major deflection movements due to the flexibility of the material or of the scraper come can. Even adherent product can be scraped off a surface.

On the other hand, the configuration is ensured that casual changes in geometry can be flexibly followed by evasive movements essentially at right angles to the extent of the section to the scraping edge.

At the same time, the configuration ensures that scraped product cannot accumulate behind the scraping edge, but rather that a narrow section of the scraper, which is not far from the scraped surface, ensures that only non-liquid product can accumulate behind the scraping edge.

A discharge area, which is grooved round between a first and fourth section of the scraper, ensures rapid fluid removal, particularly to the side, and, in particular, good spring action.

Further advantages and features of the invention result from the following description of a preferred exemplary embodiment with reference to the attached drawing. It shows:

1 is a perspective view of the scraper according to the invention,

2 shows the arrangement of the scraper according to the invention between a drum inside and an outside serving as a coolant, on which the scraping edge A scrapes the inside of the cooled outer drum in the direction of movement, and Fig. 3 shows an entire scraper rotor, which illustrates the staggered arrangement of the individual scraper sections on the outside.

In Fig. 1 it can be seen how the scraper is elongated and has an essentially U-shaped recess 28 into which a pivot pin 22, which is mounted on a support 20 provided for this purpose on the inner drum, engages parallel to both the inner the outer wall of the drum runs like the inner wall of the outer drum. The scraper 32 can be rotated about the axis of the pin on this pivot pin. It is supported on an approximately cylindrical inner surface of the two sections 12 and 14 and the contact surface of the central section 18 connecting them, and is provided with a cutout 42 which "snaps" onto the support device.

The inner drum advantageously rotates and the scraper will scrape the inside of the outer drum clockwise as shown in FIG. 2, the scraper edge A being able to be supported on the axis of rotation 22 via the thick section. The length of the section 10 is approximately 1.5 times its width, the scraping edge A ending in a tip. The advancing front facing inwards towards the product forms an angle of preferably 100-110 ° to the wall to be scraped.

The central section 18 with which the scraper is supported is in section similar to the connecting web one "H" - in simplified versions only one "V". The first longitudinal bar of the "H" is the one with a larger cross section at the top right in FIGS. 1 and 2. ne, with a scraping edge provided first section 10. Reference number "A" denotes the scraping edge.

Second and third sections 12, 14 - the two further adjacent webs, running parallel to one another to the left in the drawing, on the central section 18, which is supported on a support device 22, encompass the support device 22 and protrude approximately as far to the left as is the case Corresponds to the diameter of the support pin.

These two sections 12, 14, together with the contact surface of the central section 18 connecting them, are formed with an approximately cylindrical inner surface which runs parallel to the extension of the scraper 32, so that the scraper is rotatable about an axis (namely that of the pin) parallel to its extension on which is supported correspondingly with support device 22 having a rotationally symmetrical shape at least in the support area. When attaching the scraper, a slot or recess 42 (which is provided on the rear side of the movement) is pressed open onto the pin up to the recess provided with the cylindrical surface and is then firmly clamped.

Only by means of a fourth section 16, which rests non-positively and resiliently on a support surface 26 of the inner drum which is essentially parallel to the surface to be scraped off, is the scraper 32 rotated about the support device until the edge A abuts the surface 24 to be scraped off. The support surface is moved along with the pivot along the surface to be scraped off, so that on one or both contact edges the surfaces marked with B and C are drawn, no relative movement to the surface 26 takes place.

The fourth section 16 is provided with a smaller cross section than the first section 10 and is additionally designed to be more resilient due to grooves.

The fourth section 16 is also longer than the first section 10 and therefore bounces more, while the first section always maintains its support (force) line straight from scraping edge to pivot.

Due to the fact that the fourth section 16, in particular through the edge B with its comparatively long lever arm, is aligned essentially parallel to the surface to be scraped, both contact edges receive the desired pressure force distribution, which now essentially depends on the lever length to the pivot point.

It is further proposed to incline the leading edge 30 of the first section adjacent to the scraping edge "A" while leaving a clearance angle of 90-120 ° to the surface to be scraped off, in order to get the best movement of this, e.g. of a surface to be cooled.

Finally, the front of the scraper has a bulge, essentially parallel to the scraper axis, between the first 10 and fourth section 16 for the removal of scraped-off material - and in particular for effecting the desired spring action - which protrudes significantly inward from the front edge 30.

In Fig. 3, a scraper rotor with an inner drum (24) is shown in perspective, on which scraper sections 33 on the arranged along the outer shell th pivot pins are applied. In Fig. 3 eight such arranged along the full axial extent of the rotary drum pivot or rotary rods on the supporting them around the drum supports 20 which are attached at suitable axial intervals on the outside of the inner drum 26. The flexibility of the scraper 32 in the radial direction is so great that non-roundness (ovality) of the outer drum 24 is absorbed and compensated for in a force-fitting manner.

If the outer drum 24 and / or the inner drum 26 are not completely straight in the axial direction (e.g. have a banana-shaped axial extension), axial deviations from the scraper 32 must also be able to be accommodated. This is achieved by the fact that the scrapers 32 are not installed in their full length, but are only used as scraper sections which can better follow an axial geometry deviation. Each scraper 32 can also follow radial deviations better, so that the scraper can be made stiffer in itself than would be possible with long scraper, which would have to connect more strongly.

The pivots 22 are preferably designed as long rods in radial alignment in terms of their number and arrangement so that the scrapers 32 can be attached to them offset in the radial direction.

The inner drum 24 can be very well supported by the scraper by force closure on the sides of the outer drum. This makes it possible to dispense with a separate, radial mounting of the inner drum, so that only one driven shaft 34 is required. The scrapers 32 are preferably dimensioned in length and arrangement in the axial direction such that the respective ends overlap, so that the scrapers open at the edge the remaining product is scraped off in any case.

Claims

claims

1. Scraper with a shape with a central section (18), characterized by

a first section (10) provided with a scraping edge (A),

second and third sections (12, 14) on the central section (18), which is supported on a support device (22) which encompasses the support device (22),

these two sections (12, 14), together with the contact surface of the central section connecting them, being formed with an approximately cylindrical inner surface,

wherein the inner surface runs parallel to the extension of the scraper, so that the scraper is rotatable about an axis parallel to its extension on the support device (22), which is correspondingly rotationally symmetrical in the support area, and

a fourth section (16) which rests non-positively resiliently parallel to the first section on a support surface (26) which is at least approximately parallel to the surface to be scraped, rotating the scraper (32) around the support device (22) until the edge (A) is tight pressed against the surface to be scraped (24).

2. Scraper according to claim 1, characterized in that the at least approximately cylindrical inner surface of the two sections (12, 14) and the contact surface of the central section connecting them is provided with a recess (42) for placement on the support device (22).

3. Scraper according to one of the preceding claims, characterized in that the fourth section (16) is provided with a smaller cross section than the first section (10).

4. Scraper according to one of the preceding claims, characterized in that the fourth section (16) is longer than the first section (10).

5. Scraper according to one of the preceding claims, characterized in that the fourth section (16) with two supporting edges (B, C) is provided with recessed grooves which run parallel to the extension of the scraper.

6. Scraper according to one of the preceding claims, characterized in that the fourth section (16) is at least approximately parallel to the surface to be scraped.

7. Scraper according to one of the preceding claims, characterized in that the front edge of the first section adjacent to the scraping edge "A" while leaving a clearance angle of 90 - 120 ° to the surface to be scraped.

8. Scraper according to one of the preceding claims, characterized in that the front of the scraper between the first (10) and fourth section (16) has a bulge at least approximately parallel to the scraper axis.

9. scraper rotor for scraping a drum inside on the scraper according to one of the preceding claims, characterized by an inner drum (26) on which the radially successive scraper (32) with only a fraction of the length of the drum, axially offset from their neighbors with a slight overlap, are each arranged on pivots (22), which in turn are provided on the outside of the drum parallel to its extension over at least approximately the entire length.