DE7834365U1 - PNEUMATIC CONVEYOR LINE WITH SUPPLY AIR SUPPLY - Google Patents

Description

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Günter Weiss

Ing.

Neusalzer Str. 15

6050 Offenbach a.M.

Pneumatic delivery line with air supply

The invention relates to a pneumatic conveying line, in particular for plug-shaped conveyance of bulk materials, with controlled and metered addition of supply air through a in the conveying line located perforated air supply line.

Through the DT-PS 1 135 366 a device is known in which over the entire length of the pipeline in the lower area a porous, air-permeable material is attached and this from a air duct is enclosed. As from the description follows this device, a material transport is only in inclined or horizontal conveying direction possible. Since vertical distances often have to be overcome with pneumatic conveying, this is the case Device not suitable for this. In addition, the Line in the event of malfunctions (wear and tear on the porous material, clogging of this material on the clean air side completely unusable due to the conveyed material and dust as a result of leaks). There are also special pipes very expensive.

Furthermore, the DT - PS 1 285 3B6 is a Transport line designated in which the transport line is surrounded by an air-carrying pressure line and the material line has elastic, self-closing nozzles in its lower area has a small distance.

Another device is from DT - PS 1 200 740 known, in which an elastic, with openings that close automatically when the pressure is equal, the line is installed in subdivided individual sections and connected to a parallel pipeline carrying the compressed air.

Both devices have the disadvantage that the elastic openings easily clog and the conveyed material, in particular dust and very fine powder that can penetrate the air duct and the device thereby rendered inoperative. In addition, a second line must always be parallel to the delivery line Air ducts must be installed, including an additional, considerable one in the case of large distances Is the cost factor.

It was therefore suggested in DT-PS 1 431 672 that the air-conducting line should be applied in places to make a metallic sheath impermeable to air and thereby make the porosity controllable.

The manufacture of this air line is very complex and the line, especially the replacement, is very complex Elbow, causes considerable difficulties due to the rigidity of the air duct.

Another possibility of pneumatic transport with inner line is known from DT-PS 1 174 256. It is suggested that a B. to connect the second line and let it flow in again at short intervals, in such a way that through this Line a partial flow is transported, with many of these partial flow lines at short intervals follow one another. Further embodiments show

that the partial flow line as a separate, parallel pipeline within the transport pipe

installed. i;

This procedure is not suitable for products that tend to stick because the partial flow line closes f

sets and becomes ineffective. For abrasive products |

must due to the high speed in dBr partial flow J =

Consider the line with considerable wear.

The invention represents a solution to the disadvantages outlined, without foregoing the advantages of plug conveyance. According to the invention Uird DES ^r half a perforated compressed air leading LEI; proposed device, which is installed within an air-impermeable: · ■ permeable pipe that receives the conveyed material. In a manner known per se, it is used for

this air supply line is preferably an elastic ν

P line used, which follows the geometry of the outer '■

best adapts to the line «

The supply line is at the beginning of the delivery line introduced and permeates the whole system. The pressure drop in the supply air line is due to the dimensions much higher than the pressure drop in the transport line. The feed pressure is therefore at least 1 bar above the pressure of the transport line.

Since air constantly flows from the perforated line into the pipeline, the cross-section can in itself known way is tapered in the conveying direction. In the case of high-pressure conveyor systems, it is also common to to expand the product-carrying pipeline in the conveying direction in order to account for the expansion of the air

carry and optimize the transport speed.

It is therefore suggested that the supply air line be tapered to be chosen in such a way that the transport line has a constant diameter over the entire length can be carried out and still the transport speed is optimized. The rejuvenation will achieved in that the air supply line is divided into individual sections with different diameters uird.

About the air consumption per unit of length with different lights To keep the pressure difference to the delivery pipe constant, It is proposed to provide the individual sections with different porosities, in which case it is expedient the number and size of the pores per unit length is varied.

In order not to open the conveyor system through the supply air line, which works with higher pressure as described higher than dBm design pressure corresponding pressure level to raise, a pulse ventilation is proposed, which according to the invention depending on Delivery pressure is clocked. On a pressure transducer with minimum and maximum contact, the first Uert the minimum permissible pressure is set in the supply air line and with the second value the maximum pre-pressure. A compressed air pulse always occurs when the pressure reaches the minimum value.

In the drawings, an embodiment of the device according to the invention is shown.

Fig. 1 shows the perforated air supply line with the pulse control for compressed air.

Fig. 2 shows a pneumatic transport system with control unit and air supply line.

Fig. 3 shows schematically the pressure profile in the transport line and in the air supply line.

A transport system according to the invention consists of the transport pipe 1, the supply air line 2 and the feed sender 3 with outlet valve 4. The supply air line 2 is introduced into the transpart line 1 through the insertion nozzle 5 in an airtight manner. The pulse control unit essentially consists of the compressed air reservoir 6 and the pressure measuring device 7 with 2 adjustable switch contacts, the inlet valve 8 and the outlet valve 9. The maximum pressure is set on the pressure reducing valve 1o. After opening the valve 8, the compressed air reservoir 6 is inflated until the max contact on the pressure gauge 7 responds and the valve 8 closes again. After that valve 9 opens and the compressed air reservoir 6 relaxes in the supply air line 2. Only when the pressure is released has reached the minimum value on the pressure measuring device 7, valve 9 is closed and the compressed air tank 6 filled again. This process is repeated until the delivery process from the transmitter 3 ends is.

As shown in FIG. 2, the air supply line 2 runs through the entire transport pipe 1 and ends at Inlet port of the receiver 11. The one described above Pulse control is shown as unit 19 for reasons of illustration. The functional sequence of high pressure delivery with transmitter 3 can be assumed to be known.

The air supply line 2 is divided into 3 sections in FIG. 3, for example. The first section 12 at the beginning according to the invention, the feed has the greatest

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th diameter and has the smallest perforation with a correspondingly large distance. From the schematic assumed pressure curve can be seen that at this point the greatest pressure difference between Supply air line 2 and transport pipe 1 prevails. The inventive execution of the perforation is the air consumption per unit length is kept constant.

Similar conditions prevail in sections 13 and 14. The total is over the entire length of the line 1 the pressure in the supply air line 2 higher than in the transport pipe 1, so that no product can enter the air supply line. An automatic, elastic closure the openings is not required, so that the air supply line can be made with simple means can.

In Fig. 3 is also shown schematically that by the tapering of the air supply line 2 of free cross-section of the pipeline 1 enlarged in the transport direction. This results in the pressure curve 15 and 16 for the two systems. If the cross-section remains the same, the conveying speed will be larger due to the expansion of the air in the conveying direction, which leads to increased pressure requirements. This is what they show Curves 17 and 18.

Another option - the speed too optimize is a combination between tapering the supply air line 2 and expanding the transport line 1 workable.

Claims (5)

Protection claims 1. Pneumatic delivery line for plug delivery of bulk goods with the addition of compressed air by means of a per se known perforated, inner air supply line which is tapered in sections in the conveying direction, characterized in that the perforation of the supply air line the pressure difference between supply air line 2 and transport pipe 1 is adapted so that the air consumption per unit length is constant, with the pressure difference maintained by the pulsed feeding of compressed air into the supply air line. 2. Air supply line according to claim 1, characterized in that that the pores at the beginning of the line are smaller and at a greater distance and in the conveying direction with increasing distance and in smaller Successive intervals. 3. Air supply line according to claim 1 and 2, characterized in that the taper in the conveying direction so formed uird that the transport speed in the pipe 1 despite the expansion of the conveying air through Enlargement of the free cross-section remains optimal. 4. air supply line according to claim 1 to 3, characterized in that that the pulse control 19 always comes into force when the pressure in the air supply line 2 has reached an adjustable value that is equal to or slightly greater than the pressure in the pipe 1 is. 5. Air supply line according to claim 1 to 4, characterized in that one per pulse through the memory Defined amount of air is fed in and this memory 6 is filled again during the break will.