scholarly journals Structure Optimization of Outlet Uniformity for a Comas Tower Dryer

2021 ◽  
Vol 9 ◽  
Author(s):  
Hebin Liao ◽  
Wei Zhang ◽  
Sebastian Borucki ◽  
Jiasen Jiang ◽  
Tianqin Lin ◽  
...  

Tobacco drying is an important part in the whole process of cigarette production, and its quality is directly related to the quality of cigarettes. CTD (Comas Tower Dryer) is a new type of airflow dryer, which is widely used in the tobacco industry because of its high drying efficiency. In actual production, the uneven outlet of the tobacco cutter leads to a stacking phenomenon, which affects the subsequent process of production. In this paper, the distribution of the internal flow field of the drying tower was studied from the aspects of the overlap degree of the orifice plate and deformation of the top structure at the top of the drying tower to explore the way to optimize the inner flow field to lead to the uneven distribution of the outlet. The results show that the structure whose contact position between the wall and the outlet extending outward can improve the uniformity of the outlet, while the overlap degree of the orifice plate had no effect on the uniformity of the outlet.

2017 ◽  
Vol 9 (1) ◽  
pp. 168781401668529 ◽  
Author(s):  
Wen-wu Song ◽  
Li-chao Wei ◽  
Jie Fu ◽  
Jian-wei Shi ◽  
Xiu-xin Yang ◽  
...  

The backflow vortexes at the suction connection in high-speed centrifugal pumps have negative effect on the flow field. Setting an orifice plate in front of the inducer is able to decrease the negative effect caused by backflow vortexes. The traditional plate is able to partially control the backflow vortexes, but a small part of the vortex is still in the inlet and the inducer. Four new types of orifice plates were created, and the control effects on backflow vortexes were analyzed. The ANSYS-CFX software was used to numerically simulate a high-speed centrifugal pump. The variations of streamline and velocity vectors at the suction connection were analyzed. Meanwhile, the effects of these plates on the impeller pressure and the internal flow field of the inducer were analyzed. Numerically, simulation and experimental data analysis methods were used to compare the head and efficiency of the high-speed pumps. The results show that the C-type orifice plate can improve the backflow vortex, reduce the low-pressure area, and improve the hydraulic performance of the high-speed pump.


Author(s):  
Li Guoqi ◽  
Lin Peifeng ◽  
Cui Baoling ◽  
Jin Yingzi ◽  
Hu Yongjun ◽  
...  

With the advent of bladeless fan, technological revolutions begin to hit the industrial design world of fan. However, there is none of the developed methods on bladeless fan. To explore the excellent blowing performance of bladeless fan, numerical simulation on flow field of bladeless fan was carried out in this paper. Based on the simplified model of bladeless fan, the whole process that the airflow passes through the turbine from the inlet to the outlet slit and exit far field at last, were simulated. By comparing the flux of inlet and the flux of far outlet, the causes of flux increasing are analyzed. After analyzing static characteristics of the flow field, it shows that pressure difference is very obvious. The results obtained from velocity distribution and the characteristics of the pathlines near diffuser section and turbine, were described and analyzed. The results show that the internal flow field characteristics of bladeless fans, which we concern. The external flow field characteristics of bladeless fan was studied in the same way. And it is found that the velocity magnitude of the outlet slit and Coanda surface is much larger than other area and different positions play different roles. A general analysis on inside computational domain and outside computational domain, denotes the details about fluid motion. The research could offer reference to improvement of bladeless fan.


2014 ◽  
Vol 507 ◽  
pp. 869-873
Author(s):  
Lei Zhang ◽  
Ming Li ◽  
Yong Yao

This paper uses Reynolds stress equation turbulence model (RSM) to simulate the flue gas flow field in the new-type stack, and analyzes the velocity field and pressure field of its three-dimensional strong spiral turbulence flow field. It gets the distribution characteristics of tangential velocity, axial velocity, static pressure, dynamic pressure and total pressure in the internal flow field of the new-type stack, thus provides reference to the research and optimization design of the flow mechanism..


Author(s):  
Cui Jianzhong ◽  
Xie Fangwei ◽  
Liu Qingyun ◽  
Wang Cuntang ◽  
Zhang Xianjun ◽  
...  

A new type of canned motor pump with extensive application value is designed, researched, and developed in this article. In order to grasp the characteristic of the internal flow field of the pump, the internal flow field is simulated numerically by using FLUENT software with the standard k–ɛ turbulence model, SIMPLEC algorithm, and multiple reference frame model. The distribution of the pressure and velocity of the flow in the canned motor pump is analyzed in different working conditions. Moreover, the head and efficiency of the pump is predicted based on the simulation results, which show that the head and efficiency of the canned motor pump in small flow rate will be better. The performance of the canned motor pump can be improved by appropriately increasing the outer diameter of the impeller and the base diameter of the volute. The results of the numerical simulation are in accord with theoretical analysis, which verifies the correctness of the numerical simulation. The investigations have important theoretical guiding significance for the design of the canned motor pump.


2019 ◽  
Vol 2 (5) ◽  
Author(s):  
Tong Wang

The compaction quality of the subgrade is directly related to the service life of the road. Effective control of the subgrade construction process is the key to ensuring the compaction quality of the subgrade. Therefore, real-time, comprehensive, rapid and accurate prediction of construction compaction quality through informatization detection method is an important guarantee for speeding up construction progress and ensuring subgrade compaction quality. Based on the function of the system, this paper puts forward the principle of system development and the development mode used in system development, and displays the development system in real-time to achieve the whole process control of subgrade construction quality.


Author(s):  
Eric Savory ◽  
Norman Toy ◽  
Shiki Okamoto ◽  
Yoko Yamanishi

Author(s):  
Weihui Xu ◽  
Xiaoke He ◽  
Xiao Hou ◽  
Zhihao Huang ◽  
Weishu Wang

AbstractCavitation is a phenomenon that occurs easily during rotation of fluid machinery and can decrease the performance of a pump, thereby resulting in damage to flow passage components. To study the influence of wall roughness on the cavitation performance of a centrifugal pump, a three-dimensional model of internal flow field of a centrifugal pump was constructed and a numerical simulation of cavitation in the flow field was conducted with ANSYS CFX software based on the Reynolds normalization group k-epsilon turbulence model and Zwart cavitation model. The cavitation can be further divided into four stages: cavitation inception, cavitation development, critical cavitation, and fracture cavitation. Influencing laws of wall roughness of the blade surface on the cavitation performance of a centrifugal pump were analyzed. Research results demonstrate that in the design process of centrifugal pumps, decreasing the wall roughness appropriately during the cavitation development and critical cavitation is important to effectively improve the cavitation performance of pumps. Moreover, a number of nucleation sites on the blade surface increase with the increase in wall roughness, thereby expanding the low-pressure area of the blade. Research conclusions can provide theoretical references to improve cavitation performance and optimize the structural design of the pump.


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