Method for detecting rotate speed of flooding point of mixing kettle

A detection method and technology of stirring speed, which are applied in fluid velocity measurement, velocity/acceleration/impact measurement, measurement device and other directions, can solve the problems of inappropriate opaque stirring device, limited application range, low sensitivity, etc. The effect of a wide range of applications and low measurement conditions

Inactive Publication Date: 2009-08-26
ZHEJIANG UNIV
View PDF0 Cites 6 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, for stirred tank reactors, local detection methods are mostly invasive detection methods, which are not suitable for harsh industrial production environments, while global detection methods have their own shortcomings. For example, the observation me

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for detecting rotate speed of flooding point of mixing kettle
  • Method for detecting rotate speed of flooding point of mixing kettle
  • Method for detecting rotate speed of flooding point of mixing kettle

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] Gas-liquid mixed system, experimental equipment such as image 3 As shown, measure the rotational speed of the pan point.

[0031] The inner diameter of the stirred tank is 980mm, the material is plexiglass, and the experimental medium is air and water. The impeller is a three-layer six-blade disc turbine with a diameter of 350mm and 600L of water. The test speed is 0.83~3.33r·s -1 , ventilation volume is 0.011~0.028m 3 ·s -1 , The hydrophone probe is set on the outer wall of the stirred tank close to the bottom 1 / 4 of the static liquid level, and the sampling frequency of the vibration signal is 20kHz.

[0032] The collected vibration signal is decomposed by the second-order Daubechies multi-scale wavelet and using R / S fractal technology, the vibration signal in the frequency band with Hurst value less than 0.5 is selected as the energy fraction R of the vibration signal representing the movement of solid particles i . Investigate R i The variation with the stir...

Embodiment 2

[0037] Gas-liquid-solid mixed system, slurry polyethylene pilot plant, measuring flooding point speed, hydrophone probe placed at 2 / 5 of the static liquid level on the outer wall of the stirred tank.

[0038] The volume of the test kettle is 10L, the material is stainless steel, high-purity ethylene is used as the main raw material, a small proportion of propylene or 1-butene is used as the comonomer, hydrogen is used as the molecular weight regulator, hexane is used as the solvent, and tetrachloride is used. Titanium / ethoxymagnesium supported high-efficiency Z-N catalyst reacts at a temperature of 87°C and a pressure of 0.8MPa to produce polyethylene. A gas-liquid-solid three-phase system consisting of ethylene gas, n-hexane solvent and polyethylene solid is formed in the reactor. The stirring paddle is a disc-type turbine paddle with a blade diameter of 30 cm and a sampling frequency of 100 MHz.

[0039] Decompose the obtained signal on multiple scales and use R / S fractal t...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a method for detecting the rotate speed of the flooding point of the mixing kettle, comprising: 1) mounting a hydrophone probe head at the outer wall surface of the mixing kettle or in the mixing kettle;2) receiving the vibration signal from the inner of the mixing kettle;3) analyzing the received vibration signal by the second order Daubechies wavelet analyzing technology and selecting the vibration signal in the frequency band with the Hurst value being less than 0. 5;4)obtaining the corresponding mixing rotate speed when the energy fraction R[i] of the feature signal is increased rapidly and start to be stabilized, namely the rotate speed of the flooding point. The vibration receiving device adopting the method can be in the insertion type or in the non-insertion type, has simple and easy installation and no influence for the movement and response of the fluid; the vibration signal is generated in the movement procedure of the fruit without the emission source, thus being safe and environment-friendly; the device has lower request for the condition of measurement and can adapt to the poor condition, and has sensitive response and small measurement error and wide application range.

Description

technical field [0001] The invention relates to the detection of the operating parameters of a stirred tank, in particular to a detection method of the panning speed of the stirred tank. Background technique [0002] Stirred tank reactors are widely used in many fields, such as medicine, papermaking, food, chemical industry and wastewater treatment, etc., especially in the chemical industry, and the gas-liquid system occupies a large proportion in the operation of stirred tanks. Large gas holdup and phase boundary area, easy heat exchange and large processing capacity. Due to the complexity of the gas-liquid two-phase mixing behavior, it is difficult to design and scale up this type of stirred tank, and the pan point speed N f It is a core point in the design and operation of the stirring process after the selection of the stirring paddle is determined, and it is an important parameter to investigate the mixing effect of the stirring. Generally, the critical rotational spe...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): G01P5/24
Inventor 王靖岱王云兴阳永荣任聪静汪兵黄正梁魏舸裔张雷鸣
Owner ZHEJIANG UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap