RU2030514C1 - Ground intake of suction-tube dredger - Google Patents

Abstract

FIELD: underwater ground mining. SUBSTANCE: ground intake of suction-tube dredger has suction head, ejector head with central ejecting nozzle, ejector with nozzle and mixing chamber and diffuser. Ejector head is communicated with mixing chamber through successively installed receiving chamber and collector. Suction head is double-flow. Both flows are symmetrically connected to side surface of receiving chamber. Ejector head with central ejecting nozzle is installed between flows and coaxially connected to receiving chamber. Ejector nozzle is located on central axis of mixing chamber. EFFECT: higher efficiency. 2 dwg

Description

 The invention relates to hydromechanization and is intended for underwater mining of soil with sucker shells.

 Known suction device dredger shells [1]. Such devices are equipped with hydraulic ejectors to backwater the soil pump when developing soils at great depths. Structurally, ejectors are mainly performed according to a single-stage scheme with a central nozzle or an annular gap. The disadvantages of an ejector with an annular gap are, in particular, a restricted cross-section in the neck, which leads to its frequent blocking with soil, and thin flow guide edges that quickly wear out with the pulp passing through the neck. This helps to reduce the effectiveness of soil development.

 Closest to the technical nature of the proposed device is a device that contains a suction tip, an ejector head with a central ejector nozzle, a collector and an ejector with a mixing chamber and an ejector nozzle [2]. The ejector is equipped with an ejector nozzle in the form of inclined nozzles installed around the circumference, which must be strictly focused on the axis of the mixing chamber.

 It is not possible to practically fulfill this requirement in the welded construction of the ejector, which leads to a violation of the axisymmetry of the velocity field and the efficiency of ejection is reduced. The negative point is that the jets flowing from the nozzles installed around the circumference from the outside are screened by the wall and their active surface, through which the mass transfer with the suction stream occurs, is significantly (25-30%) reduced. In addition to the noted factors that directly affect the hydraulic efficiency of the ejector, it should be noted that the crushing of the flow of pressure water between relatively small nozzles, the number of which, under the condition of creating a uniform velocity field, is taken to be at least 6, leads to a decrease in the diameter of the jets flowing from the nozzles and, therefore, to reduce the power of the vortices acting on their surface, which determine the ability of the ejector to suck in coarse particles.

= 2,4 раза меньше) создает предпосылки к их засорению случайными включениями, попавшими в насос рабочей воды (щепки, ветошь и пр.). Важным эксплуатационным недостатком является также и то, что экранирующая струи стенка эжектора находится с ними в постоянном контакте, что приводит к ее повышенному износу. На практике это потребовало увеличить толщину стенки (утяжелить эжектор) и включить в его комплектацию специальную сменную деталь.As the experience of operating the soil sampling device showed, reducing the diameter of the nozzles (when installing six nozzles instead of one, their diameter is

= 2.4 times less) creates the prerequisites for their clogging with accidental inclusions that get into the pump of working water (chips, rags, etc.). An important operational disadvantage is the fact that the ejector shielding wall of the ejector is in constant contact with them, which leads to its increased wear. In practice, this required increasing the wall thickness (making the ejector heavier) and including a special replacement part in its package.

 The purpose of the invention is to increase the operational reliability of the device, as well as increasing the suction capacity of the jet.

 This is achieved by the fact that the ejector head is in communication with the mixing chamber by means of the receiving chamber and collector installed in series, the suction tip is made two-flow, both ducts are symmetrically connected to the side surface of the receiving chamber, the ejector head with a central ejection nozzle is installed between the ducts and coaxially connected to the receiving chamber and the ejector nozzle of the ejector is located on the central axis of the mixing chamber.

 In Fig.1 shows a soil intake device; figure 2 is a section along aa in figure 1.

 The soil intake device includes a water conduit 1, an ejector 2 with a nozzle 3, a suction nozzle 4, an ejector head 5 with a central ejection nozzle 6, a receiving chamber 7, a collector 8, a mixing chamber 9 of the ejector 2 and a diffuser 10.

 The operation of the soil intake device is as follows. The soil sampling device is lowered into the face and through the water conduit 1, pressure water is supplied to the ejector head 5 and ejector 2. The pressure water flowing from the central ejection nozzle 6 creates reduced pressure in the receiving chamber 7, due to which the suction pulp enters the soil sampling device through the two-flow suction tip 4. . The symmetrical connection of the ducts of the suction tip 4 to the receiving chamber 7 provides a good coverage of the suction stream of the expiring jet and intensive mass transfer between them. Further, this process continues in the collector 8, where the formation of the suction flow in direction and speed is completed. After passing through the manifold 8, the pulp enters the mixing chamber 9, where, under the influence of a jet flowing from the nozzle 3, the energy transfer from the pressure water to the pulp is completed and its velocity head increases. The conversion of this pressure into a mechanical one, necessary for transporting the pulp to the place of soil laying, takes place in the diffuser 10.

 Thus, the ejection process is carried out in two successive stages, which allows to reduce the loss of mixing flows due to the supply to the second stage of the suction stream preformed by the first stage.

In turn, the implementation of the second stage in the form of an ejector with a central ejection nozzle instead of a multi-nozzle type ejector gives a number of important new advantages:
the losses associated with the inevitable inaccuracy of focusing of circumferential inclined nozzles are eliminated;
there is no shielding of the jet flowing from the ejecting nozzle and its active surface is therefore reduced. In addition, the diameter of the jet and the power of the vortices acting on the surface increase. All this increases the suction capacity of the jet both in the suction mass and in the size of the solid particles contained in it;
the operational reliability of the device is increased, since the probability of clogging of a single nozzle by accidental inclusions falling into the pump of working water is reduced, and the wear specific for a multi-nozzle ejector is eliminated by the screening wall jet.

Claims (1)

 Soil-suction device for a suction pump, including a suction nozzle, an ejector head having a central ejector nozzle in communication with a water conduit that is connected to an ejector having an ejector nozzle and a mixing chamber in communication with a diffuser, characterized in that the ejector is connected in series with the ejector the receiving chamber and the collector, the suction tip is made two-flow, both its ducts are symmetrically connected to the side surface of the cameras, an ejector head with a central ejected nozzle is installed between the ducts and coaxially connected to the receiving chamber, and the ejector nozzle of the ejector is located on the central axis of the mixing chamber.

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