Movement form of hydrocyclone fluid

The hydrocyclone is a separation device that uses the principle of centrifugal sedimentation to separate or concentrate the slurry. Because of its simple structure, large workload, high separation efficiency, low cost, and low maintenance cost, it has been widely used in mineral processing, petroleum and chemical industries. The structure and size of the hydrocyclone are very important for separation. The diameter and underflow of the hydrocyclone are very important parameters that affect the working capacity and separation efficiency. For a larger cyclone diameter, the separation efficiency is low, but the working capacity is high. Therefore, if the separation efficiency of the large-diameter separator is satisfied, it is preferred. For solid-liquid hydrocyclones, increasing the underflow will increase the flow rate of the underflow. However, if the amount of underflow is too large, a large amount of water will flow out from the outlet of the underflow pipe, thus impairing the function of the underflow pipe. On the contrary, if the underflow diameter is too small, it may block solid particles, especially when the feed slurry is disturbed by a large concentration. Therefore, designing a proper hydrocyclone diameter and underflow pipe size is the key to improving the separation efficiency of the hydrocyclone.

                            

The structure of the hydrocyclone looks very simple, but the requirements for its structure, productivity, and grading effect are very high, and high matching degree can improve efficiency and productivity. Structural factors directly affect the flow form and movement mode of the fluid inside the cyclone. The fluid movement in the hydrocyclone mainly has the following forms: internal and external swirling flow, under-cover flow, balanced flow, and zero-speed envelope surface. The direction of rotation of the inner and outer swirling flow is the same, both clockwise or counterclockwise, but the direction of rotation of the swirling flow is opposite, the outer swirling flow is from top to bottom, and the inner swirling flow is from bottom to top. The underflow of the cover is also called short-circuit flow. It is due to the centrifugal force and the frictional force of the inner wall of the cylinder, a small part is suddenly released under the influence of the nozzle and pressure, first hits the top cover and then moves downward, and finally overflows with the overflow. The flow port is discharged, because this part of the slurry is directly mixed into the overflow without separation, so it directly affects the separation effect. The balance flow is two streams of two-phase fluid rotating inside and outside. Due to the different sizes of overflow ports and different insertion depths, there is no time for the slurry to be discharged from the upper and lower discharge ports, and the part of the slurry fluid that is not discharged is overflowing Between the tube and the cylinder, there is a balanced vortex movement up and down to form a balanced vortex. But this part of the exercise generally does not affect efficiency. The zero-speed envelope surface is due to the different movement directions of the inner and outer swirling flows. The inner swirling flow is formed by the movement of the outer swirling flow. Relatively speaking, there is a separation surface, that is, there is a fluid separation track with an axial velocity approaching zero. surface.