RU2310595C1 - Ejector feeder of delivery pneumotrasnsport plant - Google Patents

Abstract

FIELD: transportation of loose materials.

SUBSTANCE: proposed feeder contains rectangular section confuser-diffuser housing with feed port in zone of mating of its confuser and diffuser parts. Charging funnel with control gate arranged in lower part of funnel is placed over feed port. Hosuing is connected by its confuser and diffuser parts with confuser and diffuser which are connected, accordingly, with air duct and material duct of plant. Louver grating is arranged in housing over its entire width under feed port in diffuser part, louver slats being tilted in direction of transportation of material. Turnable valve is installed for turning on end part of louver grating over entire width of housing.

EFFECT: reduced losses of air pressure for accelerating particles of material to be transported after its delivery into feeder, reduced specific power losses of pneumotransport plant.

2 cl, 1 dwg

Description

The invention relates to devices for pneumatic transportation of bulk fine-grained materials (for example, grain) and can be used in agricultural production, flour and grain elevator and animal feed industry.

One of the simplest feeders for supplying material to a pressure pneumatic conveying installation is a shaft shutter [1]. It represents a pipe (shaft) of rectangular or circular cross section installed over the material pipe of the installation, on which a loading funnel is fixed. The pipe cross-section is blocked by the cargo valve if the material in it falls below the calculated height - the axis of rotation of the valve, and the place of material entry into the material pipe is sealed, i.e. air is prevented from entering the atmosphere.

Mine closures have a simple design, they do not cause crushing of material particles, they do not have a drive, and when unloading material from silos, the mine has a small height. The main disadvantage of shaft gates is the high height of the shaft and, consequently, the layer of material to prevent its discharge and dusting of the environment. In addition, after finishing work, a certain amount of transported material remains in the shaft shutter.

To enter the material into the injection pneumatic conveying installation, drum gateway feeders are used, consisting of a cylindrical body having a pipe for exhausting excess air, a cellular (or blade) rotating rotor and end caps [1, 2]. The feeder housing has a window for inputting material into the rotor and a window for feeding material into the material pipe of the installation. The feeder rotor is driven through the gearbox by an electric motor. This feeder introduces the material into the installation quite evenly, but the feeder is inherent in the design complexity, relatively high material and energy consumption, some grinding of particles of the transported material (due to their jamming between the rotor and the housing), as well as the ejection of part of the air from the material pipe (“scooping out” empty rotor cells).

Known ejector feeder, consisting of a rectangular housing; a confuser adapter pipe connecting the duct connected to the fan to the housing; diffuser adapter pipe connecting the housing with the material pipe of the installation [1]. In the upper part of the case there is a window on which a loading funnel is fixed. The input part of the body is made confuser, its output part is diffuser. During operation of the pneumatic conveying system, due to a decrease in the live section in the confuser part of the casing, the static pressure of the injected air is converted into kinetic energy (dynamic pressure). Due to this, a vacuum is created in the housing under the loading window and the material being transported is introduced into the housing under its own gravity, in the diffuser part it is picked up by a stream of air, and then in the diffuser adapter pipe and material conduit adjacent to the housing, it is accelerated to a steady value of the speed of movement and transported to the discharge point .

Ejector feeders do not have moving devices, i.e. they are simple in design and maintenance, small-sized and quite reliable in operation.

The technical nature and the totality of the essential features of the ejector feeder is closest to the claimed ejector feeder and it is taken as a prototype. The disadvantage of the ejector feeder is the large pressure loss to accelerate the particles of the material to the speed required for their stable movement in the material pipeline of the pneumatic conveying system. This disadvantage is due to the fact that the particles of material introduced into the ejector feeder under the action of gravity go mainly to the bottom of the housing and in the subsequent movement are concentrated in its lower part. When the allowable air velocities in the material pipe occur in pneumatic conveying installations (for example, based on the conditions of non-damage to the material particles), the value of the lifting force acting on the material particles from the air side is small, and their number in the direction from the bottom of the ejector body to its upper the plane decreases sharply. With such a distribution of material particles in the ejector body and, therefore, in the initial section of the material pipe, their path of movement increases to a speed value that ensures their stable transportation. If the air velocity is insufficient, a blockage of the ejector body or the initial section of the material pipeline is formed in the installation pneumatic system. This phenomenon can be avoided by increasing the air flow rate, but at the same time, as already noted, material particles are damaged and the power consumption of the fan drive increases significantly (as you know, it is proportional to the third degree of air speed).

The task that must be solved is to improve the working capacity and increase the reliability of the feeder and thereby the pneumatic conveying installation. This problem is solved due to the uniform distribution of the introduced particles of the material along the height of the housing of the ejector feeder, and therefore, along the height of the initial section of the material pipe. This allows you to reduce the pressure loss of the air flow to disperse the particles of the material and to prevent blockage of the casing and the initial section of the material pipe at a lower air flow rate.

The problem for the blower pneumatic conveying installation is solved using the proposed ejector feeder, in which a louvre grill [3] is installed under the supply window of the housing along its entire width, on the end of which, at the angle to its plane, the swivel is also pivotally mounted with the possibility of rotation valve.

The scheme of the ejector feeder of the injection pneumatic conveying installation is shown in the drawing.

The ejector feeder of the injection pneumatic conveying installation consists of a rectangular section of the housing 1, the inlet of which is made confuser, and the outlet is diffuser. The upper part of the housing 1 has a supply window 2 located in the interface between the confuser and diffuser parts of the housing. A loading funnel 3 is installed above the window 2, on the lower part of which there is an adjustment flap 4. The inlet (confuser) part of the housing 1 is connected to the air duct 6 by the confuser 5, which, in turn, is connected to the installation fan (not shown in the diagram). The output (diffuser) part of the housing 1 by the diffuser 7 is connected to the material pipe 8 of the installation. Inside the casing 1, under the supply window 2 and in the diffuser part of the casing 1, a louvre grill 9 is placed along its entire width, the louvers 10 of which are inclined in the direction of transporting the material. A rotatable valve 11 is pivotally mounted on the end part of the louvre grille 9 (point O) over the entire width of the housing 1.

The operation of the ejector feeder proceeds as follows. When the adjusting flap 10 is set to the “open” position from the loading funnel 3, it is introduced into the housing 1 through the supply window 2. At the same time, the air flow from the duct 6 by the confuser 5 is introduced into the housing 1 and acts on the material particles entering it. At the same time, the air flow, meeting on its way the louvre grille 9 and the rotatable valve 11, is divided into three parts. The upper part of the flow moving between the louvre grille 9 and the upper part of the housing 1 acts on the particles of material introduced into it and moves them in the direction of transportation. The middle part of the air flow entering the wedge-shaped space formed by the louvre grille 9 and the rotatable valve 11 leaves this space in the form of jets through the openings of the louvre grille 9 formed by its louvres 10. Under the influence of the kinetic energy of the jets, the material entering the louvre grille 9 is brought into fluidized state, thereby enhancing the "blowing" effect of the first part of the air flow on the transported material in the oversize space. The third part of the air flow moves through the space formed by the lower part of the housing 1 and the rotatable valve 11, acts on the particles of material coming from the louvre grille 9, and thereby prevent it from entering the lower part of the diffuser 7 and material pipe 8.

With such a “combined” effect of the air flow on the transported material, its particles uniformly fill the inner space of the material pipeline 8. Due to this, they are accelerated to a value of a stable transportation speed on a shorter travel path, thereby reducing the loss of air pressure on the acceleration of material particles. In addition, with the marked nature of the effect of the air flow on the transported material in the feeder of the pneumatic conveying installation, obstruction is eliminated in it and in the zone of the pneumatic system adjacent to the feeder at lower air flow rates, as a result of which the specific energy costs for transporting the material are reduced.

The capacity of the feeder, and therefore the pneumatic conveying system, is changed using the adjustment flap 4, and a more uniform distribution of material particles along the height of the body 1 of the feeder, diffuser 7 and the initial part of the material pipe 8 is achieved by controlling the amount of air introduced per unit time under the louvre grille 9 by changing the position rotatable valve 11.

Thus, due to the proposed ejector feeder, the pressure loss of the air flow to accelerate the particles of the transported material is reduced to a speed value that ensures their stable movement, which, in turn, leads to a decrease in the specific energy consumption of the pneumatic conveying installation. An additional effect is achieved due to a more complete use of working time due to the elimination of blockages of the ejector feeder, diffuser and material pipe of the pneumatic conveying system.

Literature

1. Zuev F.G. Pneumatic transportation at grain processing enterprises. - M .: Kolos, 1976 .-- 344 p.

2. Ievlev N.A. Operation of pneumatic conveying systems at woodworking enterprises. - M .: Forest industry, 1982. - 215 p.

3. Blokhin P.V. Air duct for transporting grain. - M .: Kolos, 1981. - 111 p.

Claims (2)

1. An ejector feeder of an injection pneumatic conveying installation, comprising a rectangular housing, the inlet of which is made confuser, and the outlet is diffuser; a supply window made on the upper part of the housing, in the interface zone of its confuser and diffuser parts; a loading funnel with an adjustment flap located above the feed window; a confuser and a diffuser connecting the housing, respectively, with the air duct and material pipe of the pneumatic conveying system, characterized in that a louvre grille is installed in the housing under the supply window and in the diffuser part of the housing along its entire width, on the end of which a rotatable pivotally is mounted pivotally valve. 2. The ejector feeder according to claim 1, characterized in that the louvres of the louvre grille are inclined in the direction of transportation of the material.