RU2115611C1 - Powder-like material pneumatic transportation method - Google Patents

Abstract

FIELD: power engineering. SUBSTANCE: method comes to filling service container with powder like material above minimum level and emptying it down to minimum level. Minimum level is determined basing on condition to preclude fluidizing of gas through fill level of powder-like material in service container. Pulse delivery of gas into powder like medium along entire length of transportation pipeline is additionally provided. Gas pulse pressure is chosen basing on condition to exclude fluidization of gas in pulse delivered through summary layer of powder-like material in transportation pipeline and material fill level in service container. EFFECT: reduced consumption of gas and increased reliability. 1 dwg

Description

 The invention relates to the field of power engineering and can be used for pneumatic conveying of ash from electrostatic hoppers.

 The closest in technical essence to the proposed method is a method of pneumatic conveying of a powdery medium, which consists in filling the supply tank with a powdery medium to the calculated level and sealing it, supplying gas under the inlet of the transport pipeline and emptying the supply tank through the latter, into which the pulse gas is supplied to the powdery Wednesday, along the length of the transport pipeline.

 The disadvantages of the method are low reliability, due to the need for the introduction of shut-off elements in an abrasive medium (ash) to seal the supply container, a significant flow of air (gas) for aeration of the powdery medium and its displacement from the supply container.

 The objective of the invention is to provide a method characterized by a low air flow rate for pneumatic conveying of the powdered medium to the calculated height, and high reliability of the nodes of the device that implements the method. The technical result is to reduce air consumption and increase reliability.

 This is achieved by the fact that in the method of pneumatic conveying of the powdered medium, which consists in filling the supply container with a powdered medium, supplying gas to the supply container under the inlet of the transport pipeline and emptying the supply container through the transport pipeline, an additional pulse supply of gas to the powder medium is carried out to the length of the transport pipeline, filling of the supply capacity with a powdery medium is performed above the minimum level, and emptying to a minimum level, with min mal level is determined from the condition precluding fluidization gas through the bulk level powdery medium in the supply tank and the gas pressure in the pulse is selected from exception conditions fluidization incoming pulse gas through the aggregate layer powdery medium in the transport pipe to the inlet and the bulk layer in the supply tank.

 The above set of features allows to reduce air consumption for pneumatic transport of a powdery medium and to increase the reliability of a device that implements the method by eliminating nodes operating in a powdery medium.

 The invention is illustrated by the drawing, which displays the cycles of the considered method.

 A device that implements the method includes a supply tank 1, connected with the collection hopper 2 in the upper part, a transport pipe 3, the inlet elbow of which is located in the lower part of the supply tank 1. Under the inlet of the transport pipe 3, a continuous gas supply pipe 4 is installed, and on the wall transport pipeline 3 - tube for pulsed gas supply.

 The powdery medium through the collection hopper 2 enters the consumable tank until the minimum level recorded by the signaling device (not shown), which causes the inclusion of the gas supply valve into the tube 4, is reached.

 In the zone between the outlet openings of the tube 4 and the inlet of the transport pipeline, a local increase in pressure and the outflow of the powdered medium in the inhibited layer through the transport pipeline 3 to a height corresponding to the value of the pressure mentioned occurs, to diaphragm a layer of the powdered medium in the transport pipeline 3, a diaphragm is installed, which provides reduction of air consumption for pneumatic transport. The pressure value under the inlet of the transport pipeline 3 is limited by the bulk level of the powdery medium in the supply tank 1 to fulfill the condition that excludes fluidization of the gas through it. In the case of gas fluidization through the bulk level, the gas consumption for pneumatic transport of the powder medium increases.

 From the above restrictions, the height of the pneumatic transport will approximately correspond to the bulk level in the supply tank 1. To increase the height of the pneumatic transport on the transport pipeline below the level of rise of the powdery medium, a pulsed gas supply is carried out.

 The first pulse of gas supplied through the tube 5 (see the drawing), cuts off a portion of the powder medium and, due to the pressure drop in the resulting gas cavity and the output end of the transport pipeline, moves this portion through the transport pipeline.

 During the movement through a portion of the powdered medium, gas fluidization occurs, the pressure in the gas cavity becomes lower than the total pressure in the section between the introduced gas pulse and the inlet of the transport pipeline filled with the powdered medium. The latter, due to the constant pressure at the inlet of the transport pipeline, moves along the length and again fills the gas pulse input section. The next gas pulse also cuts off a portion of the powdery medium and moves it through the transport pipeline.

 The gas pressure in the pulse should not exceed the value causing the fluidization of the gas entering the pulse through the total layer of powdery medium in the transport pipeline and the bulk level in the supply tank. If this value is exceeded, pneumatic transport through the transport pipeline will not be carried out.

 The minimum gas pressure in the pulse is selected from the conditions of the set height of pneumatic transport, i.e. pressure losses of pneumatic transport.

 The volume of a portion of gas in a pulse should be minimal to reduce the gas flow rate for fluidization through a portion of a powdery medium.

 In the case of continuous gas supply to the transport pipeline due to the fact that the pressure at the gas supply point will exceed the pressure in the powder medium, pneumatic transport of the latter will be impossible.

 Thus, using a bulk layer of powdered medium of a minimum set level and a pulsed gas supply to the powdered medium in the transport pipeline, an exception is made to the flow vessel from the design of the upper valve. The displacement of the powdery medium from the supply tank when gas is supplied only under the inlet of the transport pipeline determines pneumatic transport in the inhibited layer, which reduces air consumption and wear on the walls of the pipeline. It is possible to control the speed of pneumatic transport (and porosity of the medium) by changing the cross section of the diaphragm installed in the transport pipeline.

Claims (1)

 The method of pneumatic conveying of a powdered medium, which consists in filling the supply container with a powder medium, supplying gas to the supply container under the inlet of the transport pipeline, and emptying the supply container through the transport pipeline, in addition, pulse gas supply to the powder medium along the length of the transport pipeline is carried out, characterized in that the filling the supply capacity of the powdery medium is produced above the minimum level, and emptying to a minimum level, and The minimum level is determined from the condition that excludes fluidization of the gas through the bulk level of the powdery medium in the supply tank, and the gas pressure in the pulse is selected from the condition of excluding fluidization of the gas entering the pulse through the total layer of the powdery medium in the transport pipeline to the bulk level in the supply tank.