When sucking materials, the design of the suction nozzle is also particularly important. Suction nozzles can be divided into rotary suction nozzles and angular suction nozzles. Rotary suction nozzles are generally used for materials with poor fluidity, while angular suction nozzles are generally used for cabins and carriages, with joints connected to circular cross-section feeding pipes.

    1. Rotating suction nozzle Suction type pneumatic conveying deviceIt is difficult to extract materials with poor fluidity, such as conventional coal and crushed coal, sand, cement, fertilizers, bauxite, soybean residue, corn residue, crushed soybean cake, sawdust, etc. To improve the suction capacity of the nozzle, using a rotating nozzle is an effective method.

    A rotary suction nozzle is made by installing various loose feeding devices on the basis of a straight suction nozzle. When it is inserted into the feeding layer for material suction, it continuously rotates to loosen the material and mix it thoroughly with air, so it can be continuously sucked into the inner tube of the suction nozzle for conveying, thereby improving the feeding efficiency.

    There are various structural forms of rotary suction nozzles, with the most commonly used being those with mechanical loosening devices. The feeding component is located at the suction port of the nozzle, which is equipped with three loose feeding knives evenly distributed at 120 ° to each otherInstall two rows of loose and collapsed materials along the circumference of the outer cylinder of the suction nozzle at an appropriate heightEach row of components is equipped with three landslide loosening knives evenly distributed at 120 °There are two blades. The collapse radius depends on the characteristics of the material and the range of the material pile (ship type, vehicle)The production capacity of the suction and delivery system, etc., shall be determined according to specific conditions. When suckingWhen the mouth rotates in the material layer, the material pile continuously collapses and is loosened and stirred, allowing the material to mix well with the air, thus ensuring continuous and sufficient suction of the material.

    The design of the feeding blade shape should be conducive to collecting materials towards the suction port, while the collapse and loosening blade shape should be conducive to material collapse and mixing. The design of the blade shape should also pay attention to reducing cutting resistance and having sufficient structural strength.

    A supplementary air duct is installed around the suction nozzle to introduce the material layer and mix it thoroughly with the material, adjusting the mixing ratio to achieve a suitable level and facilitating the material to start. The effective total area of the supplementary air duct can be determined by approximately equal to the inner duct area.

    The rotation of the suction nozzle is achieved by the motor 6 through the reduction device 5. The rotation speed of the suction nozzle depends on the physical properties of the material, such as block size, fluidity, humidity, etc., and can generally be selected between 40-60x/min. It is more suitable to use 50r when sucking and transporting coal. Generally, materials with high humidity and block size are unloaded at lower speeds. The power of the driving motor is related to the size of the device and the characteristics of the material. For example, using an 11kW motor on the rotating suction nozzle of a large coal suction machine for 200 hours of production can ensure normal operation.

    The working performance of the rotating suction nozzle is related to factors such as the rotational speed, the shape and configuration position of the feeding and collapsing knives, the amount of supplementary air flow, and the depth of the feeding layer of the suction nozzle. For various materials, it is necessary to select and determine the optimal parameters through experiments and continuous summarization of experience in practical use. 

In addition to the mechanical rotary suction nozzle mentioned above, there are also various other suction nozzles that use high-pressure air to loosen or fluidized materials, as well as those that use ultrasonic waves to activate powdered materials.

    2. Angle shaped suction nozzles are commonly used for cleaning materials from narrow areas such as cabins, carriages, and warehouses, especially during the cleaning stage of unloading ships.

    The structure of angular suction nozzle. Its lower part is a rectangular structure, and the upper part of the suction nozzle is connected to a circular cross-section feeding pipe through a transition pipe and a movable joint. The inlet part of the corner suction nozzle is equipped with a round steel bar welded protective barrier, which can prevent large debris from entering and provide a certain gap when approaching the cabin floor or ground, ensuring that the suction pipe is not blocked when continuing to feed. Supplement the air duct to introduce air and regulate the concentration of two-phase flow. Adjust the opening of the air volume control panel to control the size of the supplementary air volume. For ease of movement, the corner suction nozzle is welded with a handle. Due to the frequent movement of the suction nozzle, its weight should not be too large. Generally, the diameter of the feeding hose connected to a single person operated suction nozzle should not exceed 125-150mm, and the diameter of the connecting hose for a double person operated suction nozzle should not exceed 150-175mm. In large suction type unloading devices, in order to reduce the weight of the cleaning suction nozzle, the air supply speed is often determined. The suction nozzle can generally be welded with steel plates with a thickness of 0.8-1.2mm. If conditions permit, lightweight materials should be used for production.

    There are various forms of suction nozzles used in the upper deck of large sea vessels, some of which are equipped with mechanical aggregate devices in front of the nozzle, which can be moved by a small car or pulled by a steel wire rope to collect materials at different positions inside the cabin.

Therefore, the equipment selected for different sites and materials is different. If you need pneumatic conveying equipment, please feel free to contact us,Shandong JuhengOur experts will design the optimal pneumatic conveying solution for you, making the conveying more efficient.