Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G53/00—Conveying materials in bulk through troughs, pipes or tubes by floating the materials or by flow of gas, liquid or foam
  • B65G53/34—Details
  • B65G53/40—Feeding or discharging devices
  • B65G53/42—Nozzles

Definitions

• the invention relates to a device for the pneumatic conveying of fine material, containing a container intended for receiving the fine material, in the bottom area of which a nozzle for supplying a gaseous conveying medium is arranged, which protrudes into the open lower end of a conveying pipe which extends vertically through the interior of the container runs and is guided outwards from the upper region of the container, the nozzle and the lower end of the delivery pipe being adjustable relative to one another in the axial direction.
• containers are known in the bottom area of which a nozzle for supplying a gaseous conveying medium is fixedly arranged, which protrudes into the open lower end of a conveying pipe.
• the gaseous conveying medium emerging from the nozzle at high speed entrains fine material from the lower region of the container into the conveying pipe.
• a change in the amount of fine material conveyed can take place within the limits of the type of conveying equipment by influencing the amount of conveying gas.
• a sensitive adjustment of the quantity of goods to be conveyed within wide limits as well as a quick stop of the conveyance if necessary are not possible with these known conveying devices.
• Conveyors of the type mentioned at the outset have also been developed, in which the nozzle and the lower end of the conveyor tube are in the axial direction can be adjusted relative to one another, for example by moving the nozzle more or less far into the conveying tube and thereby changing the gap between the nozzle and the conveying tube for the entry of the fine material accordingly.
• the invention is therefore based on the object, while avoiding these deficiencies of the known designs, of designing a pneumatic conveying device of the type mentioned at the outset in such a way that, even in the case of fine material which is difficult to flow and / or has a tendency to build up, it adjusts the quantity of conveyed material sensitively wide limits enables, if necessary, a quick stop of the conveyance as well as an immediate empty blowing of the delivery pipe and the subsequent delivery line and, moreover, allows a desired restart with a low delivery rate
• the nozzle and the lower end of the conveyor tube form a shut-off valve which blocks or releases the fine material entry into the conveyor tube
• a metering valve which can be controlled as a function of the pressure in the conveyor pipe is arranged in the conveyor pipe near its outlet from the container.
• the height-adjustable nozzle is thus at the lower end of the
• Conveyor tube not used to adjust the quantity of material to be conveyed, but only as a shut-off valve that blocks or releases the conveyance.
• the quantity of material to be conveyed (when the shut-off valve is open) is adjusted by means of the metering valve which is arranged in the conveyor pipe near its outlet from the container.
• O ⁇ VPI Distribute the fine material entering the delivery pipe approximately symmetrically to the nozzle evenly over the cross-section of the delivery pipe before it comes into the area of the metering valve after the fine material has accelerated in the first part of the vertical delivery section.
• the metering valve works at a point on the pneumatic conveying path at which there is pure flight promotion and approximately uniform flow conditions are present.
• Dosing valve is arranged close to the outlet of the delivery pipe from the container and not at a greater distance from the container. Only at one close to
• the position of the metering valve provided in the container results in a short response time for the change in the quantity of fine material in the conveying line connected to the conveying pipe.
• shut-off valve Since the shut-off valve is located at the lower end of the delivery pipe, when this valve is closed (ie when the fine material entry into the delivery pipe is interrupted), no troublesome crop plug builds up in the riser pipe, since this initially continues through the nozzle inflowing medium blows the delivery pipe freely. In this way, problems caused by a plug in the conveyor pipe when starting up are avoided.
• the device according to the invention is expediently operated in such a way that
• shut-off valve is opened at the start of a subsidy and shut off at the end
• the pressure in the delivery pipe is measured, the value is compared to a predetermined target value and the metering valve is adjusted as a function of the difference between the actual value and the target value.
• the flow velocity in the area of the metering valve is expediently between 10 and 30 m / s, preferably between 15 and 22 m / s, and the fine material loading of the gaseous conveying medium between 0.3 and 6, preferably between 0.5 and 4 kg Fine goods / kg pumped medium.
• Tukt ⁇ T 1 shows a schematic side view of a conveyor device according to the invention
• FIG. 2 shows a detail (according to II) from FIG. 1.
• the device shown for example for the pneumatic conveying of coal dust, contains a fine material storage silo 1 with a pressure-shock-resistant filter 2 and an explosion chimney 3, as well as a conveying container 4, which is only used as a
• a conveying gas line 7 opens into the bottom region of the conveying container 4 via a nozzle 6.
• a conveying pipe 8 is arranged centrally in the conveying container 4, the lower edge 8a of which has a fixed clear distance from the bottom 4a of the conveying container 4.
• the delivery pipe 8 is led through the ceiling 4b of the delivery container 4 to the outside and connected via a bend 28 to a delivery line 29 connected to a consumer.
• a metering valve 30, which is formed, for example, by a rotatable flap, is arranged in the rectilinear part of the conveyor tube 8 (i.e. even before the elbow 28) in the conveyor tube 8, just behind the outlet of the conveyor tube 8.
• a pressure measuring probe 31 is provided in the delivery line 29 and is connected to a controller 32. This controller also contains a setpoint signal 33 and supplies an output signal 34 to a servomotor 35 which is used to set the
• a vent line 9 leads from the ceiling 4b of the conveying container 4 to a flame flashback fuse 10.
• the nozzle 6 in the lower region of the delivery container forms, together with the lower edge 8a of the delivery tube 8, a shut-off valve.
• the nozzle 6, which has a conical shape with a cone slope of approximately 1: 2.5, is axially relative to the lower edge 8a of the delivery pipe 8 between a lower (opening) by a pneumatic actuating cylinder 11 in a sliding guide 12 -) Position and an upper (closed) position adjustable.
• the nozzle 6 In the lower position, the nozzle 6 leaves an annular gap through which the fine material located in the conveying container 4 can enter the conveying tube 8 under the action of the gaseous conveying medium emerging from the nozzle in the direction of arrow 21 (arrows 22 ). In the upper position, on the other hand, the nozzle 6 bears against the lower edge 8a of the delivery pipe 8 and thus closes the annular gap between the nozzle and the delivery pipe, interrupting the fine material conveyance.
• the lower area of the conveying container 4 is provided with a ventilation device 13.
• a pneumatically actuated Butterfly valve 14 and an explosion protection valve 15 are arranged in the feed gas line 7.
• the conveyor device described is particularly suitable for dosing dusts, for example coal dust, in the lower output range (from about 100 kg to 5000 kg / h).
• the metering valve 30 is expedient in a straight part of the delivery pipe
• the metering valve 30 emerges directly behind the Au, the delivery pipe 8 emerges from the conveying container 4, but is arranged in front of the subsequent elbow 28, embodiments are also possible within the scope of the invention in which the metering valve is just behind this elbow 28 is arranged in the conveyor line 29.
• the pressure measuring point (pressure measuring probe 31) is expediently arranged in the delivery pipe 8 or in the subsequent delivery line 29 - seen in the flow direction - behind the metering valve 30.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Air Transport Of Granular Materials (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=6131495

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Family Cites Families (12)

• 1981
  • 1981-05-05 DE DE19813117748 patent/DE3117748A1/de not_active Withdrawn
• 1982
  • 1982-04-25 EP EP82901415A patent/EP0078286A1/de not_active Withdrawn
  • 1982-04-25 WO PCT/EP1982/000087 patent/WO1982003844A1/en unknown
  • 1982-05-03 ZA ZA822999A patent/ZA822999B/xx unknown
  • 1982-05-04 ES ES511918A patent/ES511918A0/es active Granted

Non-Patent Citations (1)

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