Multi-axis low-rotating-speed spiral rotor in heat exchange tube

Abstract

The invention relates to a multi-axis low-rotating-speed spiral rotor in a heat exchange tube. The multi-axis low-rotating-speed spiral rotor mainly comprises a hollow shaft, turbulence shafts and spiral blades, wherein the spiral blades are positioned on the surface of the hollow shaft; the outer diameter of each spiral blade is smaller than the inner diameter of the heat exchange tube; the surface of each spiral blade is smooth; the spiral blades take a shape of spiral around the hollow shaft; a turbulence shaft structure is arranged on an upstream face of the spiral blades in the axial direction of the hollow shaft, so as to effectively increase tangential velocity and radial velocity of fluid; the cross sections of the turbulence shafts are partially circular or partially oval; the axial length of each turbulence shaft is equal to or smaller than that of each spiral blade; the turbulence shafts and the hollow shaft are parallel or form included angles with a certain degree; and a downstream face of the spiral blades does not have the turbulence shaft structure so as to reduce pressure loss when the fluid passes the rotor. According to the invention, the bending direction of crimping edges at the tops of the spiral blades is opposite to rotating direction of the spiral blades, so that on the premise of not increasing radial height of the blades, the radial velocity of the fluid is increased, the axial acting force of the rotor is reduced, the radial perturbation of the rotor to the fluid is enhanced, and the self-aligning effect is good.

Description

technical field [0001] The invention relates to an insert device applied to the energy-saving technology of a shell-and-tube heat exchanger, in particular to a multi-axis low-speed helical rotor with enhanced heat exchange and self-cleaning functions, low energy consumption, high efficiency, and long service life. Background technique [0002] In our country, most of the energy consumed by energy-consuming industries is thermal energy, which is basically realized through the heat exchange process. Typical heat exchange equipment such as condensers of steam turbines in power plants, evaporators in caustic soda and soda ash production units, and ethylene cracking furnaces generally suffer from high energy consumption, low heat exchange efficiency, easy fouling and fouling, frequent cleaning, and waste liquid cleaning The problem of large emissions. The national policy of "energy saving and emission reduction" has effectively promoted the development of enhanced heat transfer ...

AI Technical Summary

Problems solved by technology

There is generally layered dirt on the inner wall of the shell and tube heat exchanger, which leads to an increase in the resistance of the fluid in the pipeline. In severe cases, the pipeline will be blocked, and the heat transfer performance will be greatly reduced; Energy is wasted. At the same time, the dirt is generally corrosive, and the pipe wall will be corroded. If the fluid leaks, it will cause a major safety hazard. Therefore, the traditional treatment method is to be forced to stop production for cleaning, which not only delays the production progress of the factory, but also Need to pay expensive cleaning fees; in order to better solve these problems, people have been studying various methods and devices for non-stop online automatic heat transfer enhancement and descaling and anti-scaling

As a typical tube-side enhanced heat transfer method, the insert has also attracted people's attention. One of them is to use the fluid to drive the spiral bond to rotate to realize the method of strengthening online automatic descaling. The Chinese patent application number of the spiral bond is: ZL95236063 .2. The patent name is "cleaning device for descaling and anti-scaling in heat transfer tube". This device plays a certain role in strengthening heat exchange and anti-scaling and descaling. As a whole, it directly scrapes the heat transfer tube and damages the inner wall of the heat exchange tube; (2) When the fluid flows, it requires a large driving torque to push the link to rotate, and consumes more fluid kinetic energy; (3) The bearing used for single-end fixing The service life is short; (4) The field synergy enhanced heat transfer effect generated by the bond is not significant

But the disadvantage is that when a certain fluid passes through, the rotation speed of the rotor is determined by the helix angle of the flight. When the flight lead is small, the rotation speed of the rotor is fast, and the resistance to the fluid increases accordingly; in order to solve this problem , China Patent Application No. 201110050891.8, the name of the invention is "Radial Stepped Rotor in Heat Exchange Tube". The device is composed of a rotor, a support frame and a connecting axis. Fixed on the support frame, multiple rotors are installed on the connecting axis. The rotor is composed of a hollow shaft and blades. The blades are stepped. Each blade is in the same inclined shape as the hollow shaft. The passing performance is good, but the fluid resistance of this structure is relatively large, the flow rate at start-up is too high, the axial force of the rotor superimposes a large force on the pendant and the shaft, and the life of the shaft will be reduced. The arrangement of the rotor blades described above is uniformly distributed in the On the hollow shaft, in order to facilitate the installation of the rotor, there is a large distance between the outer diameter surface of the rotor and the inner diameter surface of the heat exchange tube, so that the enhanced heat transfer and anti-scaling and descaling capabilities of the rotor are limited to a certain extent

In addition, the rotor will shake during the rotation process, and the top of the blade will scratch the inner wall of the heat exchange tube, which will also reduce its service life. Therefore, the rotor should have a better centering effect in the heat exchange tube to reduce its friction. The scraping effect with the inner wall of the heat exchange tube prolongs its service life

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