Technological trends in the automotive industry toward a software-defined and autonomous vehicle require a reassessment of today’s vehicle development process.The validation process soaringly shapes after starting wi...Technological trends in the automotive industry toward a software-defined and autonomous vehicle require a reassessment of today’s vehicle development process.The validation process soaringly shapes after starting with hardware-in-the-loop testing of control units and reproducing real-world maneuvers and physical interaction chains.Here,the road-to-rig approach offers a vast potential to reduce validation time and costs significantly.The present research study investigates the maneuver reproduction of drivability phenomena at a powertrain test bed.Although drivability phenomena occur in the frequency range of most up to 30∙Hz,the design and characteristics substantially impact the test setup’s validity.By utilization of modal analysis,the influence of the test bed on the mechanical characteristic is shown.Furthermore,the sensitivity of the natural modes of each component,from either specimen or test bed site,is determined.In contrast,the uncertainty of the deployed measurement equipment also affects the validity.Instead of an accuracy class indication,we apply the ISO/IEC Guide 98 to the measurement equipment and the test bed setup to increase the fidelity of the validation task.In conclusion,the present paper contributes to a traceable validity determination of the road-to-rig approach by providing objective metrics and methods.展开更多
New attacks are emerging rapidly in Information Security; hence the tools and technologies available for securing the information needs substantial upgradation as well as skills for operationalization to mitigate thes...New attacks are emerging rapidly in Information Security; hence the tools and technologies available for securing the information needs substantial upgradation as well as skills for operationalization to mitigate these attacks. It requires creation of practical training environment with tools and technologies available for Information Security. The design of Information Security courses involves scenario based hands-on-labs with real time security incidents and problems with global reach which could be customized quickly as per the scenario and user＇s requirement. In order to understand the underlying concepts as well as to learn the practical aspects of network and system security environment, an initiative has been taken and a Virtual Test Bed has been developed to meet the above objectives. It is an essential component in Information Security training concept which could be used to perform actual security attacks and remedial measures as well as to test the effectiveness of protection mechanisms and help in handling the security incidents effectively. This paper discusses the development of this Test Bed for Information Security skill development with virtual training environment using which Information Security concepts, attacks on networks/systems and practical scenarios are simulated for imparting hands on training to participants.展开更多
Chinese Chang＇e lunar exploration project aims to collect and return subsurface lunar soil samples at a minimum penetration depth of 2 m in 2017. However, in contrast to those on the Earth, automated drilling and sam...Chinese Chang＇e lunar exploration project aims to collect and return subsurface lunar soil samples at a minimum penetration depth of 2 m in 2017. However, in contrast to those on the Earth, automated drilling and sampling missions on the Moon raise the risk of burning bits. Test-beds are required for testing the thermal properties of drill tools in a lunar environment. In this paper, a novel temperature measuring method based on thermocouples and a slip ring was proposed. Furthermore, a data acquisition system for a drilling process was designed. A vacuous, cryogenic, and anhydrous soil environment simulating the lunar surface was established. A drilling test-bed that can reach a depth of 2.2 m was developed. A control strategy based on online monitoring signals was proposed to improve the drilling performance. Vacuum and non-vacuum experiments were performed to test the temperature rising effect on drill tools. When compared with the non-vacuum experiment, the vacuum temperature rise resulted in a 12 ℃ increase. These experimental results provide significant support for Chinese lunar exploration missions.展开更多
The energy consumption of a teaching building can be effectively reduced by timetable optimization.However,in most studies that explore methods to reduce building energy consumption by course timetable optimization,se...The energy consumption of a teaching building can be effectively reduced by timetable optimization.However,in most studies that explore methods to reduce building energy consumption by course timetable optimization,self-study activities are not considered.In this study,an MATLAB-EnergyPlus joint simulation model was constructed based on the Building Controls Virtual Test Bed platform to reduce building energy consumption by optimizing the course schedule and opening strategy of self-study rooms in a holistic way.The following results were obtained by taking a university in Xi’an as an example:(1)The energy saving percentages obtained by timetabling optimization during the heating season examination week,heating season non-examination week,cooling season examination week,and cooling season non-examination week are 35%,29.4%,13.4%,and 13.4%,respectively.(2)Regarding the temporal arrangement,most courses are scheduled in the morning during the cooling season and afternoon during the heating season.Regarding the spatial arrangement,most courses are arranged in the central section of the middle floors of the building.(3)During the heating season,the additional building energy consumption incurred by the opening of self-study rooms decreases when duty heating temperature increases.展开更多
The relation of mass, stiffness and rate of damping is obtained by using the mechanical analysis of the obstructive vibration system of two dimensions for the design of the obstructive vibration system of more freedom...The relation of mass, stiffness and rate of damping is obtained by using the mechanical analysis of the obstructive vibration system of two dimensions for the design of the obstructive vibration system of more freedom and the micro vibration test bed. The result of stimulational experiment indicates that the isolation of vibration of this system is satisfactory. The design method of vibration can be used as the reference to ultra precision machine tool, super micro orientation machanism and so on.展开更多
Energy conservation and emission reduction are the focus worldwide.Farm vehicle engine would be more efficient if it is injected a little hydrogen during work,meanwhile,the emission of the vehicle would be decreased.N...Energy conservation and emission reduction are the focus worldwide.Farm vehicle engine would be more efficient if it is injected a little hydrogen during work,meanwhile,the emission of the vehicle would be decreased.Nowadays,there are many kinds of onboard hydrogen production methods,among which the microwave plasma method is regarded as the best.In order to develop an onboard hydrogen production system using microwave plasma,a new corresponding test bed was designed and developed in this research.The ethanol,water and air from the three supply pipelines were mixed and evaporated into gas mixture,and then the mixture was further created into hydrogen through microwave plasma reaction.In the test bed,a hydrogen production environment required for the reaction was provided,and hydrogen would come into being when the air was broken down by the plasma under the conditions of 0.1-0.7 atm.Furthermore,the reaction conditions could be controlled precisely,and real-time environmental data and spectral data could be collected during the hydrogen production.The experimental results showed that onboard hydrogen production could be achieved on this test bed,and the hydrogen amount produced could be adjusted to simulate real vehicle working conditions.In addition,the system is of rapid response,high precision and reliability,which can be applied in new products developments of the onboard hydrogen production system.展开更多
Drill sampling has been widely employed as an effective way to acquire deep samples in extraterrestrial exploration. A novel sampling method, namely, flexible-tube coring, was adopted for the Chang＇e mission to acqui...Drill sampling has been widely employed as an effective way to acquire deep samples in extraterrestrial exploration. A novel sampling method, namely, flexible-tube coring, was adopted for the Chang＇e mission to acquire drilling cores without damaging stratification information. Since the extraterrestrial environment is uncertain and different from the terrestrial environment, automated drill sampling missions are at risk of failure. The principles of drilling and coring for the lunar subsurface should be fully tested and verified on earth before launch. This paper proposes a test-bed for conducting the aforementioned experiments on earth. The test-bed comprises a rotary-percussive drilling mechanism, penetrating mechanism, drilling medium container, and signal acquisition and control system. For granular soil, coring experiments indicate that the sampling method has a high coring rate greater than 80%. For hard rock, drilling experiments indicate that the percussive frequency greatly affects the drilling efficiency. A multi-layered simulant composed of granular soil and hard rock is built to test the adaptability of drilling and coring. To tackle complex drilling media, an intelligent drilling strategy based on online recognition is proposed to improve the adaptability of the sampling drill. The primary features of this research are the proposal of a scheme for drilling and coring a test-bed for validation on earth and the execution of drilling experiments in complex media.展开更多
In order to verify the feasibility of semi-automatic garlic planter with inclined belt program and determine its reasonable operating parameters, the semi-automatic test-bed with inclined belt of garlic transplanting ...In order to verify the feasibility of semi-automatic garlic planter with inclined belt program and determine its reasonable operating parameters, the semi-automatic test-bed with inclined belt of garlic transplanting machine was designed, and the garlic box experiments were conducted. The angle of inclined belt on the test-bed and its running speed were adjustable. Single factor test results showed that the program of the semi-automatic garlic planter with inclined belt was feasible, and the angle of inclined belt and the test bed running speed affected the indicators. Orthogonal experiment results showed that the angle of inclined belt was the main factor affecting the test indicators. It is also found that the best angle was 30 degrees, while the most reasonable running speed was 0.75 Km/h.展开更多
A new simplified removable ground test-bed was designed for testing a certainturbofan engine. The facilities are 5.5 m long, 1.5 m wide, 2.2 m high and not more than 4. 5 t ofits empty weight. There are four rubber wh...A new simplified removable ground test-bed was designed for testing a certainturbofan engine. The facilities are 5.5 m long, 1.5 m wide, 2.2 m high and not more than 4. 5 t ofits empty weight. There are four rubber wheels that could be towed. There is an independentelectrical measurement and control system to test the rotational speed of rotors, the gas pressureof the compressor, the exhaust gas temperature, etc. Cooperated with the oil truck and the electricpower supply truck, the turbofan engine could be preserved on the ground and started to the idlingregime. While running, the parameter of the engine could be recorded, disposed and displayed. Inaddition, the facilities were successfully applied to the plateau experiment in order to researchhow the atmosphere pressure affects the start of engines. Some data are given in the paper.展开更多
The HCPB concept has been a European DEMO reference concept for nearly one decade. Detailed thermal-hydraulic study on the control behavior of the whole system is one of the important parts of this development. The th...The HCPB concept has been a European DEMO reference concept for nearly one decade. Detailed thermal-hydraulic study on the control behavior of the whole system is one of the important parts of this development. The thermal-hydraulic effect of the TBM-combined cooling circuit during a cyclic operation in ITER has been studied using the system code RELAP5. The RELAP5 is based on an one-dimensional, transient two-fluid model for the flow of a two-phase steam-water mixture that can contain noncondensable components like Helium. The RELAP5models are modified to take the cyclic operation of the circulator, heat, exchanger, bypass, valves etc in to account. A sequence of operational phases is investigated, starting from the cold state through the heating phase that brings the system to a stand-by condition, followed by typical power cycles applied in ITER. The results show that the implemented control mechanisms keep the inlet temperature to the TBM and the total mass flow rate at the required values through all phases.展开更多
A systematic, accurate and robust evaluating method for fine pitch printed circuit board （PCB） positioning assessment in testing fixture is developed. Targeting reliability of bed-of-nails tester is successfully eva...A systematic, accurate and robust evaluating method for fine pitch printed circuit board （PCB） positioning assessment in testing fixture is developed. Targeting reliability of bed-of-nails tester is successfully evaluated by the 2D pattern transform. Probe offset vector with its Weibull and Gaussian distribution estimates are obtained for further investigation about the causes of misalignment on the basis of a batch tests for same kind of PCBs.展开更多
[ Objective] The study aims to discuss the feasibility of using a fixed biological bed to treat low-concentration organic waste gas. [ Method] A fixed biological bed was used to treat low-concentration organic waste g...[ Objective] The study aims to discuss the feasibility of using a fixed biological bed to treat low-concentration organic waste gas. [ Method] A fixed biological bed was used to treat low-concentration organic waste gas from a phosphate workshop, and then the waste gas treated was assessed by human sense of smell to determine the most economical empty bed contact time, thereby verifying the feasibility of using a fixed biolog- ical bed to treat low-concentration organic waste gas. [Result] When empty bed contact time was 60 s, the smell of the treated waste gas was acceptable, and COD value of recycled water in the fixed biological bed was essentially unchanged. It proved that organic load of the waste gas was consumed by microorganisms within 60 s. [ Conclusion] It is feasible to use a fixed biological bed to treat Iow-concantration organic waste gas from a phosphate workshop.展开更多
The temperature distribution of iron ore pellet bed in grate has a significant effect on pellet production and quality control, but the related work is scarce. A well-designed test was successfully carried out by mean...The temperature distribution of iron ore pellet bed in grate has a significant effect on pellet production and quality control, but the related work is scarce. A well-designed test was successfully carried out by means of tracking measurement and the temperature distribution and variation in pellet layers were obtained. The effects of blast tem- perature, blast velocity and oxidation reaction on the pellet layer temperature were studied. According to the analy- sis, the inlet air temperature in the up-draught drying zone （UDD） and blast temperature in the Preheating I （PH I） zone should be raised, and the length of the down-draught drying zone （DDD） should be properly increased.展开更多
Granular material mechanics,finite element analysis and crushing theory are applied to study the compressive comminution mechanism of particle beds in this paper.This is a new method by which we have established an eq...Granular material mechanics,finite element analysis and crushing theory are applied to study the compressive comminution mechanism of particle beds in this paper.This is a new method by which we have established an equivalent model of granular material,determined the values and distributions of contact forces and discovered a crushing law.The model has been tested on the newly designed equipment and proved to be correct.Some new characteristics and laws of compressive comminution of particle beds have been found.展开更多
The effectiveness of deep-bed filtration with respect to suspension formed during the preceding processes is evaluated by the test of filterability. The properties and concentration of the suspension being filtered ar...The effectiveness of deep-bed filtration with respect to suspension formed during the preceding processes is evaluated by the test of filterability. The properties and concentration of the suspension being filtered are affected by the efficiency of the preceding aggregation and separation processes. The basic principles of the test of filterability are based on the mechanistic model of filtration. The equations in the mathematical model of the mechanistic conception of filtration are derived from the theory of filtration. The arrangement of the pilot filtration plant for the determination of filterability of flocculent suspension is presented in this paper. The test of filterability is carried out with a thin-layer filter element. The design of a filter element arrangement and its installation are also disclosed in this paper. The inter-dependence of the coefficient of filtration efficiency on the specific volume of intercepted suspensions, filter media grain sizes and different filtration velocities are graphically presented. In addition, the effect of the filter bed clogging resulting from the properties of different suspensions on the head loss generated, the length of filtration cycle and quality of filtrate produced are also shown in this paper.展开更多
文摘Technological trends in the automotive industry toward a software-defined and autonomous vehicle require a reassessment of today’s vehicle development process.The validation process soaringly shapes after starting with hardware-in-the-loop testing of control units and reproducing real-world maneuvers and physical interaction chains.Here,the road-to-rig approach offers a vast potential to reduce validation time and costs significantly.The present research study investigates the maneuver reproduction of drivability phenomena at a powertrain test bed.Although drivability phenomena occur in the frequency range of most up to 30∙Hz,the design and characteristics substantially impact the test setup’s validity.By utilization of modal analysis,the influence of the test bed on the mechanical characteristic is shown.Furthermore,the sensitivity of the natural modes of each component,from either specimen or test bed site,is determined.In contrast,the uncertainty of the deployed measurement equipment also affects the validity.Instead of an accuracy class indication,we apply the ISO/IEC Guide 98 to the measurement equipment and the test bed setup to increase the fidelity of the validation task.In conclusion,the present paper contributes to a traceable validity determination of the road-to-rig approach by providing objective metrics and methods.
文摘New attacks are emerging rapidly in Information Security; hence the tools and technologies available for securing the information needs substantial upgradation as well as skills for operationalization to mitigate these attacks. It requires creation of practical training environment with tools and technologies available for Information Security. The design of Information Security courses involves scenario based hands-on-labs with real time security incidents and problems with global reach which could be customized quickly as per the scenario and user＇s requirement. In order to understand the underlying concepts as well as to learn the practical aspects of network and system security environment, an initiative has been taken and a Virtual Test Bed has been developed to meet the above objectives. It is an essential component in Information Security training concept which could be used to perform actual security attacks and remedial measures as well as to test the effectiveness of protection mechanisms and help in handling the security incidents effectively. This paper discusses the development of this Test Bed for Information Security skill development with virtual training environment using which Information Security concepts, attacks on networks/systems and practical scenarios are simulated for imparting hands on training to participants.
基金supported by the China Academy of Space Technology (CAST)
文摘Chinese Chang＇e lunar exploration project aims to collect and return subsurface lunar soil samples at a minimum penetration depth of 2 m in 2017. However, in contrast to those on the Earth, automated drilling and sampling missions on the Moon raise the risk of burning bits. Test-beds are required for testing the thermal properties of drill tools in a lunar environment. In this paper, a novel temperature measuring method based on thermocouples and a slip ring was proposed. Furthermore, a data acquisition system for a drilling process was designed. A vacuous, cryogenic, and anhydrous soil environment simulating the lunar surface was established. A drilling test-bed that can reach a depth of 2.2 m was developed. A control strategy based on online monitoring signals was proposed to improve the drilling performance. Vacuum and non-vacuum experiments were performed to test the temperature rising effect on drill tools. When compared with the non-vacuum experiment, the vacuum temperature rise resulted in a 12 ℃ increase. These experimental results provide significant support for Chinese lunar exploration missions.
基金supported by the National Natural Science Foundation of China (52008328)National Key Research and Development Project (2018YFD1100202)+1 种基金the Science and Technology Department of Shaanxi Province (2020SF-393,2018ZDCXL-SF-03-04)the State Key Laboratory of Green Building in Western China (LSZZ202009).
文摘The energy consumption of a teaching building can be effectively reduced by timetable optimization.However,in most studies that explore methods to reduce building energy consumption by course timetable optimization,self-study activities are not considered.In this study,an MATLAB-EnergyPlus joint simulation model was constructed based on the Building Controls Virtual Test Bed platform to reduce building energy consumption by optimizing the course schedule and opening strategy of self-study rooms in a holistic way.The following results were obtained by taking a university in Xi’an as an example:(1)The energy saving percentages obtained by timetabling optimization during the heating season examination week,heating season non-examination week,cooling season examination week,and cooling season non-examination week are 35%,29.4%,13.4%,and 13.4%,respectively.(2)Regarding the temporal arrangement,most courses are scheduled in the morning during the cooling season and afternoon during the heating season.Regarding the spatial arrangement,most courses are arranged in the central section of the middle floors of the building.(3)During the heating season,the additional building energy consumption incurred by the opening of self-study rooms decreases when duty heating temperature increases.
文摘The relation of mass, stiffness and rate of damping is obtained by using the mechanical analysis of the obstructive vibration system of two dimensions for the design of the obstructive vibration system of more freedom and the micro vibration test bed. The result of stimulational experiment indicates that the isolation of vibration of this system is satisfactory. The design method of vibration can be used as the reference to ultra precision machine tool, super micro orientation machanism and so on.
文摘Energy conservation and emission reduction are the focus worldwide.Farm vehicle engine would be more efficient if it is injected a little hydrogen during work,meanwhile,the emission of the vehicle would be decreased.Nowadays,there are many kinds of onboard hydrogen production methods,among which the microwave plasma method is regarded as the best.In order to develop an onboard hydrogen production system using microwave plasma,a new corresponding test bed was designed and developed in this research.The ethanol,water and air from the three supply pipelines were mixed and evaporated into gas mixture,and then the mixture was further created into hydrogen through microwave plasma reaction.In the test bed,a hydrogen production environment required for the reaction was provided,and hydrogen would come into being when the air was broken down by the plasma under the conditions of 0.1-0.7 atm.Furthermore,the reaction conditions could be controlled precisely,and real-time environmental data and spectral data could be collected during the hydrogen production.The experimental results showed that onboard hydrogen production could be achieved on this test bed,and the hydrogen amount produced could be adjusted to simulate real vehicle working conditions.In addition,the system is of rapid response,high precision and reliability,which can be applied in new products developments of the onboard hydrogen production system.
基金Supported by National Natural Science Foundation of China(Grant No.51105092)Introducing Talents of Discipline to Universities(111 Program,Grant No.B07018)+1 种基金Heilongjiang Postdoctoral Grant(Grant No.LBHZ11168)China Postdoctoral Science Foundation(Grant No.2012M520722)
文摘Drill sampling has been widely employed as an effective way to acquire deep samples in extraterrestrial exploration. A novel sampling method, namely, flexible-tube coring, was adopted for the Chang＇e mission to acquire drilling cores without damaging stratification information. Since the extraterrestrial environment is uncertain and different from the terrestrial environment, automated drill sampling missions are at risk of failure. The principles of drilling and coring for the lunar subsurface should be fully tested and verified on earth before launch. This paper proposes a test-bed for conducting the aforementioned experiments on earth. The test-bed comprises a rotary-percussive drilling mechanism, penetrating mechanism, drilling medium container, and signal acquisition and control system. For granular soil, coring experiments indicate that the sampling method has a high coring rate greater than 80%. For hard rock, drilling experiments indicate that the percussive frequency greatly affects the drilling efficiency. A multi-layered simulant composed of granular soil and hard rock is built to test the adaptability of drilling and coring. To tackle complex drilling media, an intelligent drilling strategy based on online recognition is proposed to improve the adaptability of the sampling drill. The primary features of this research are the proposal of a scheme for drilling and coring a test-bed for validation on earth and the execution of drilling experiments in complex media.
文摘In order to verify the feasibility of semi-automatic garlic planter with inclined belt program and determine its reasonable operating parameters, the semi-automatic test-bed with inclined belt of garlic transplanting machine was designed, and the garlic box experiments were conducted. The angle of inclined belt on the test-bed and its running speed were adjustable. Single factor test results showed that the program of the semi-automatic garlic planter with inclined belt was feasible, and the angle of inclined belt and the test bed running speed affected the indicators. Orthogonal experiment results showed that the angle of inclined belt was the main factor affecting the test indicators. It is also found that the best angle was 30 degrees, while the most reasonable running speed was 0.75 Km/h.
文摘A new simplified removable ground test-bed was designed for testing a certainturbofan engine. The facilities are 5.5 m long, 1.5 m wide, 2.2 m high and not more than 4. 5 t ofits empty weight. There are four rubber wheels that could be towed. There is an independentelectrical measurement and control system to test the rotational speed of rotors, the gas pressureof the compressor, the exhaust gas temperature, etc. Cooperated with the oil truck and the electricpower supply truck, the turbofan engine could be preserved on the ground and started to the idlingregime. While running, the parameter of the engine could be recorded, disposed and displayed. Inaddition, the facilities were successfully applied to the plateau experiment in order to researchhow the atmosphere pressure affects the start of engines. Some data are given in the paper.
基金The project supported by European Fusion Development Agreement (EFDA) Technology Work Program
文摘The HCPB concept has been a European DEMO reference concept for nearly one decade. Detailed thermal-hydraulic study on the control behavior of the whole system is one of the important parts of this development. The thermal-hydraulic effect of the TBM-combined cooling circuit during a cyclic operation in ITER has been studied using the system code RELAP5. The RELAP5 is based on an one-dimensional, transient two-fluid model for the flow of a two-phase steam-water mixture that can contain noncondensable components like Helium. The RELAP5models are modified to take the cyclic operation of the circulator, heat, exchanger, bypass, valves etc in to account. A sequence of operational phases is investigated, starting from the cold state through the heating phase that brings the system to a stand-by condition, followed by typical power cycles applied in ITER. The results show that the implemented control mechanisms keep the inlet temperature to the TBM and the total mass flow rate at the required values through all phases.
基金This project is supported by US Pennsylvania Dept. of Community & Economic Development(No.20-906-0015)National Natural Science Foundation of China(No.50390064, No.50575230)National Basic Research Program of China(973 Program, No.2003CB716202).
文摘A systematic, accurate and robust evaluating method for fine pitch printed circuit board （PCB） positioning assessment in testing fixture is developed. Targeting reliability of bed-of-nails tester is successfully evaluated by the 2D pattern transform. Probe offset vector with its Weibull and Gaussian distribution estimates are obtained for further investigation about the causes of misalignment on the basis of a batch tests for same kind of PCBs.
文摘[ Objective] The study aims to discuss the feasibility of using a fixed biological bed to treat low-concentration organic waste gas. [ Method] A fixed biological bed was used to treat low-concentration organic waste gas from a phosphate workshop, and then the waste gas treated was assessed by human sense of smell to determine the most economical empty bed contact time, thereby verifying the feasibility of using a fixed biolog- ical bed to treat low-concentration organic waste gas. [Result] When empty bed contact time was 60 s, the smell of the treated waste gas was acceptable, and COD value of recycled water in the fixed biological bed was essentially unchanged. It proved that organic load of the waste gas was consumed by microorganisms within 60 s. [ Conclusion] It is feasible to use a fixed biological bed to treat Iow-concantration organic waste gas from a phosphate workshop.
基金Sponsored by National High Technology Research and Development Program of China (2007AA05Z215)
文摘The temperature distribution of iron ore pellet bed in grate has a significant effect on pellet production and quality control, but the related work is scarce. A well-designed test was successfully carried out by means of tracking measurement and the temperature distribution and variation in pellet layers were obtained. The effects of blast tem- perature, blast velocity and oxidation reaction on the pellet layer temperature were studied. According to the analy- sis, the inlet air temperature in the up-draught drying zone （UDD） and blast temperature in the Preheating I （PH I） zone should be raised, and the length of the down-draught drying zone （DDD） should be properly increased.
文摘Granular material mechanics,finite element analysis and crushing theory are applied to study the compressive comminution mechanism of particle beds in this paper.This is a new method by which we have established an equivalent model of granular material,determined the values and distributions of contact forces and discovered a crushing law.The model has been tested on the newly designed equipment and proved to be correct.Some new characteristics and laws of compressive comminution of particle beds have been found.
文摘The effectiveness of deep-bed filtration with respect to suspension formed during the preceding processes is evaluated by the test of filterability. The properties and concentration of the suspension being filtered are affected by the efficiency of the preceding aggregation and separation processes. The basic principles of the test of filterability are based on the mechanistic model of filtration. The equations in the mathematical model of the mechanistic conception of filtration are derived from the theory of filtration. The arrangement of the pilot filtration plant for the determination of filterability of flocculent suspension is presented in this paper. The test of filterability is carried out with a thin-layer filter element. The design of a filter element arrangement and its installation are also disclosed in this paper. The inter-dependence of the coefficient of filtration efficiency on the specific volume of intercepted suspensions, filter media grain sizes and different filtration velocities are graphically presented. In addition, the effect of the filter bed clogging resulting from the properties of different suspensions on the head loss generated, the length of filtration cycle and quality of filtrate produced are also shown in this paper.
