RU2195422C2 - Device for continuous pressure charging of containers and pipelines with loose materials - Google Patents

Abstract

FIELD: pneumatic transportation systems. SUBSTANCE: device for feeding loose materials into flow of transportation air has hopper receiving material, pressure auger, auger sleeve, dust plug chamber, mixing chamber, transportation pipeline and compressed air delivery union. Auger is set into operation by electric motor. Mixing chamber is made in form of part of transportation pipeline with diameter equal to that of transportation pipeline. Hole made in auger sleeves to discharge transportation agent pressure from auger sleeve. EFFECT: possibility of effectively and easily loading of pipelines and containers with loose materials under pressure. 1 dwg

Description

 The invention relates to a device for continuous loading of bulk materials of containers and pipelines under pressure and can be used in pneumatic conveying systems in various industries.

 Known boot device for loading bulk materials - ejector type feeders. In ejector-type feeders, bulk material enters the transport pipeline of the pumping unit due to the rarefaction created at the inlet end of the pipe by a stream of compressed air directed towards the conveyor. This type of feeder is mainly used for transporting powdered bulk materials to a distance of 150 m. However, their productivity and efficiency are not high, which is the main reason that hinders the widespread use of this equipment [1].

 Known gateway feeders used in the pneumatic overload of pulverized and granular materials. They are the most common loading devices in low and medium pressure units of the discharge type. However, due to the need to ensure reliable sealing between the rotor and the housing, they can be used when transporting a narrow range of bulk materials in terms of physical and mechanical properties. Abrasive and sticky bulk materials lead to rapid wear or jamming of the rotor [1].

 Known pneumatic chamber feeder, which consists of one or more reservoirs, each of which has an opening in the upper part with a valve that cuts off the flow of bulk materials and a sealing valve, and in the lower part an unloading pipe connected to a horizontal or vertical pipeline, inlet pipes and compressed air discharge with shutoff valves.

 Chamber feeders are large in size, which leads to an increase in capital investment in the construction of premises for their placement. Chamber feeders operate cyclically [1].

 Known screw feeders designed to enter bulk materials into the flow of conveying air at a pressure drop of up to 0.3 MPa.

 Devices with a screw feeder and an air chamber with a top discharge of the air mixture are called pneumatic lifts [1].

 Known screw feeders type PSHM, not having a check valve. The pitch of their auger turns decreases toward the aerial camera, which allows the flour to be compacted and a cork made from it, which prevents the breakthrough of compressed air from the aerial camera into the receiving chamber.

 Screw feeders, air chambers of which have horizontal discharge of air mixture into the transport pipeline and are equipped with one or several nozzles along with the aerofoil, are called pneumatic screw pumps [1].

 Pneumatic screw pumps are designed, as a rule, for a higher pressure of compressed air than pneumatic hoists, and their discharge screw is equipped with a check valve.

 Closest to the proposed device (prototype) is a known screw feeder device used in injection installations for the transportation of pulverized and granular cargoes. The feeder is a screw with a variable step decreasing along the material. The screw is connected by a coupling to the electric motor. Material from the hopper flows by gravity through the loading pipe into the feeder, where it is fed by a rotating screw into the mixing chamber [2].

 In the process of moving along the screw, the material is compacted due to the reduced pitch of the screw. This prevents compressed air from entering the mixing chamber through the screw into the hopper. Compressed air is supplied through nozzles to the lower part of the mixing chamber, where an aerosol mixture of the desired concentration is created. From the mixing chamber, the material moves with compressed air to the discharge wire of the pneumatic device. In the event that the screw stops supplying material to the mixing chamber, the inlet of the feeder is closed by an adjustment flap, due to which the flow of air from the mixing chamber into the hopper is stopped.

 The disadvantages include a relatively high energy consumption, design complexity. The invention is aimed at creating a more efficient and simpler device for the continuous loading of bulk materials into pipelines and containers under pressure.

 The problem is solved in that the mixing chamber is made in the form of a transport pipeline and has the same diameter as the transport pipeline, into which a fitting is inserted for supplying a transport agent (air). As a result, it is not necessary to produce a special, complex design, mixing chamber with nozzles or a fabric partition for aeration of the material and a check valve with a counterweight. To prevent the breakthrough of compressed air from the mixing chamber through the screw sleeve into the loading chamber and thereby stopping the process of loading material into the loading chamber, the pipe for forming a compressed dust plug is made (inner surface) in the form of a truncated cone. The cone is made from a smaller diameter to a larger one in the direction of movement of the material, and when the auger stops and the supply of material stops, the plug is compressed by the back pressure of air over a large area of the base of the cone and air in the pipeline cannot push the plug and break into the loading chamber. To ensure non-penetration of air into the loading chamber and stopping the loading of material in the auger sleeve, a hole is made for venting air from the sleeve. The hole is made at a distance of more than one step from the cut-off of the intake end of the sleeve and thereby the intake turns of the screw are always filled with material and feed the latter into the screw sleeve, the screw constantly feeds the material and a compressed dust plug is created again, which prevents the penetration of compressed air from the mixing chamber into the loading chamber.

 The height of the truncated cone of the cork, as well as the larger diameter, are selected depending on the density and fraction of the bulk material in practice.

 The hole is separated from the outlet cut of the sleeve at a distance not less than the step of the screw, since the last turn of the screw is pressing, and if the hole is made in the area of the step of the screw, then the material pressed by the last turn of the screw will be ejected through the hole.

 The drawing shows a device in section.

 The device includes a housing with a receiving hopper 1 for receiving bulk material, a loading auger 2, a sleeve of a loading auger 3, a chamber for a dust plug 5 and a pipe 6 for mixing air with bulk material, and also a fitting 7 for supplying compressed air. The auger is driven by an electric motor 8. An unloading hole 4 is made in the auger sleeve for discharging accidentally bursting air into the auger sleeve. The screw 2 is mounted on the shaft of the electric motor 8 and has a uniform pitch of turns. The specific dimensions and materials of the individual elements of the device are determined by the type of bulk material, the physicochemical properties of the medium of the bulk material, and the manufacturing process conditions.

 The device operates as follows.

 Bulk material from the hopper under its own weight is fed into the loading hopper 1 of the device, where the loading coils of the screw material 2 are fed into the sleeve and then into the chamber for the formation of dust plug 5. When creating a dense dust plug, the transport agent is switched on, which enters the transport agent through the nozzle 7 pipeline 9, where, mixing with the material, it transports it to its destination.

 Using the proposed device allows you to effectively, simply and continuously load transport pipelines and containers under pressure.

Sources of information
1. I.N. Bogdanov. Pneumatic transport in agriculture. M .: Rosagropromizdat, 1991, p. 16, 17, 19.

 2. A. A. Geyman. Hoisting and transport devices in the pulp and paper and wood-chemical industries. Vol. 3, revised. Forest industry, 1978, p. 196.

Claims (2)

 1. A device for introducing bulk materials into the flow of conveying air, including a hopper for receiving material, a pressure screw with a motor drive, a sleeve, characterized in that the mixing chamber is made as part of a transport pipeline and has the same diameter as the transport pipeline, and a hole is made in the screw sleeve for depressurizing the transport agent from the screw sleeve.  2. The device according to claim 1, characterized in that the hole is located at a distance of more than one step of the screw from the beginning of the sleeve and from its end.