FR2624489A1 - TRANSPORT PIPING FOR THE DELIVERY OF BULK PRODUCT - Google Patents

Abstract

A transport pipe for the pneumatic conveying of bulk product, which totally or at least substantially prevents the formation of angel hair, has on its inner wall projections directed towards the inside of the pipe, the radial height of which is in the range of about 10mu to 1mm.

Description

i The present invention relates to a pipeline

  of transport for the pneumatic conveying of

  duit in bulk, provided with projections provided on the internal wall of the transport pipe, directed towards

inside the pipe.

  Such transport lines are customary

  in metal, sometimes also in plastic

  tick or glass. In order to keep the resistance low

  friction and in order to prevent or at least

  slow the formation of deposits on the wall, the canali-

  feed stations have so far been preferably

with smooth wall.

  It is known that in the case of the transport in particular of certain loose products in granular form, angel hair appears to a small extent, thus objects in the form of hair, fibers or skeins. This angel hair is very annoying for the subsequent handling of the bulk product,

  because they tend to clump together in larger clusters

  tants near silos, gravity or circulation mixers, separators and the like,

  affect the functioning of the installation parts

  concerned or even may lead to inter-

  operating disruptions. Milking facilities

  subsequent bulk products also require

  usually that the bulk product cannot

  hold angel hair, so it should

  be separated by appropriate devices. The Che-

  wanna angel probably form almost exclusive-

  by friction of particles of bulk material

  on the inner wall of the transport pipe.

  The measures taken so far were therefore

  focused on keeping this friction at a low level

  ble thanks to smooth-walled transport pipes and the lowest possible conveying speeds. A transport pipe of the type indicated in the preamble is known from American patent N 4,621,953. The projections directed towards the inside of the pipe, which are preferably arranged only in the elbows of the pipe and only on the internally arched internal walls, do not however serve to prevent the formation of angel hair but are intended to prevent wall erosion of

  the pipeline. The protrusions must diffract the sheet

  of the bulk product and are therefore very

  preferably pyramid-shaped with a

  radial height of the order of magnitude 2.5 cm.

  It is also known from the published German patent application 2,008,989 to provide the inner wall of the pipe with a recess transport pipe.

  shallow depth. Here too, the goal is not to delete

  sea angel hair formation but to prevent the

establishment of clusters on the wall.

  The object of the invention is therefore to

  read a transport pipe that prevents sensitive-

  the appearance of angel hair.

  According to the invention, this problem is solved in a transport pipe of the type indicated in the

  preamble, by the fact that the height of the projections

  lifts radially to less than about 1 mm.

262448-9

  While in the case of massive and high protrusions, as they are provided in the case of the transport pipe according to American patent 3,117,821, the appearance of angel hair is further favored, it has been surprisingly found

  than with the low projections proposed

  formally with the invention, the desired object is achieved, although on the other hand this profiling of the internal wall of the transport pipe constitutes a measure increasing the friction, therefore also deviates from the path followed so far to maintain weak training

  angel hair by the lowest friction possible

  between the particles of bulk material and the inner wall of the pipe. The flow processes responsible for the success of the measurements according to the invention have not yet been clarified in detail, but it is assumed that the projections, while overall increasing the friction, and the time, during which the particle or the isolated grain of product in bulk is in contact with

  the wall of the pipe, are kept short, so that

  also the surface heating caused by friction of the bulk product particle remains low.

  Advantageous configurations of the pipeline

  tion of transport according to the invention consists in that the height of the projections rises radially to 'at least 10, u .; the axial projection distance located at least approximately on the same generator is at most equal to approximately two diameters of the pipe,

  the projections are created by depressions or

  radial indentations from the wall of the pipeline

  transport; the projections are formed by

  cements or annular radial imprints of the wall of the transport pipe; the protrusions consist of a recess or a radial, helical imprint of the wall of the transport pipe;

  the projections are formed by coatings

  daptant on the internal surface of the transport pipe in the form of metal grids, lattice

  metallic, spiral or the like.

  A transport pipe according to the invention is shown schematically simplified according to two

  embodiments selected for illustrative purposes only

ple on the accompanying drawings.

  Figure 1 shows a first embodiment. Figure 2 shows a second embodiment.

  Figure 3 shows in partial section at large

  of scale the detail "X" in Figures 1 and 2.

  Figure 4 shows a third embodiment. Transport line 1 shown on

the designs can be made of metal.

  In order to obtain protrusions 2 (see Figure 3) directed inwards, in the first form

  (Figure 1), the wall la of the pipe-

  tion 1 is provided at intervals with annular fingerprints

  laires 3. These imprints 3 can be made afterwards also in the assembled state using appropriate tools. But instead of this, the pipe 1 can already be fitted with impressions, during the manufacture (for example during the extrusion process),

  which need not necessarily follow one another

  rement, which generate projections 2 directed towards the

  térieur. In the embodiment according to Figure 2, the projections 2 are generated from the outside by a depression 4 or a helical imprint of the wall of the pipe. Connected to a generator,

  projections 2 follow one another at interval b.

  Certainly in the two embodiments shown, the projections 2 directed radially towards

  the inside of the tube are made continuously-

  in the circumferential direction, but the depressions-

  may also be in the form of isolated bumps (seen from inside the tube) or isolated imprints or bumps (seen from the outside). The height d (cf. FIG. 3) of the projections 2 must amount to at least 10 / ,, but also remain less than approximately 1 mm. The axial spacing a in Figure 1 or b in Figure 2 can in principle be chosen small in any way, but in any case should not be greater than two pipe diameters, so

  to achieve the desired effect to a sufficient extent.

  In accordance with Figure 4, the above effect can

  also be obtained by the fact that in a pipe-

  smooth wall transport 5, we introduce and

  fixes a structure 6 in the form of a flexible sheath, which

  adapts to the inner wall of the transport pipe.

  The structure can be produced in the form of a trellis-

  lily, grid, fabric or the like of metal or

made of plastic.

Claims (7)

CLAIMS R E V E N D I C A T I 0 N S   1. Transport pipe for the pneumatic conveying of bulk product, provided with projections provided on the internal wall of the transport pipe, directed towards the inside of the pipe, characterized in that the height (d) of the projections (2 )   rises radially to less than about 1 mm.   2. Transport pipe according to claim 1, characterized in that the height (d) of the projections   <2) amounts radially to at least.Op.   3. Transport pipe according to claim 1 or 2, characterized in that the axial spacing (a, b) of projections (2) located at least approximately on the same generator is at most equal to about two pipe diameters.   4. Transport pipeline according to any one   claims 1 to 3, characterized in that the   projections (2) are created by indentations or radial indentations in the wall of the transport pipe. 5. Transport pipeline according to any one   claims 1 to 4, characterized in that the   projections (2) consist of recesses or annular radial indentations (3) in the wall of the transport pipeline.   6. Transport pipeline according to any one   claims 1 to 4, characterized in that the   projections (2) are formed by a recess or a radial, helical impression (4) of the wall of the transport pipeline.   7. Transport pipeline according to any one   claims 1 to 4, characterized in that the   protrusions are formed by coatings fitting onto the internal wall of the transport pipe (1) in the form of metal grids, trellises   of metal, spirals or the like.