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The filtration of mixed dust that included a small number of melted (liquid) particles was studied in an experimental granular bed filter (GBF). Results show that the collection efficiency of dust containing melted particles is higher than that of dust composed of solid particles but the pressure drop from the former is higher than that of the latter. The collection efficiency and pressure drop increase as the concentration of melted particles increases. A surface sliding GBF exhibits good comprehensive performance when filtering dust, especially dust containing a mix of solid and liquid particles. The effects of the gas temperature, gas velocity, sliding filter bed thickness, and sliding collector flux on filter performance were also examined. Based on the experimental results, correlations for the collection efficiency and pressure drop for mixed dust are presented.

Introducing vibrations is a common way to improve the granular flow in silos to avoid clogging. In this study, a three-dimensional silo submitted to vertical vibration was built. The effect of vibration on the discharge of tilted silo was studied. The results showed that, the discharge rate did not depend on the particle depth but decreased with the increase of the outlet tilt angle, regardless if the silo was vibrated or not. Discharge rate showed non-monotonic relationship with vibration frequency at high amplitude, while increased with increasing frequency at low amplitude. The contour plots of the influence of vibration and tilt angle on the discharge were given. Based on the analysis of variance (ANOVA), the effect of the tilt angle on the discharge was higher than the vibration amplitude and frequency.

Although the filtration efficiency can be increased because of the use of small-sized particles in granular beds, the bed pressure drop may be increased. This study presents a numerical solution of a moving bed that can facilitate instantaneous separation of binary particles into a top layer of larger particles and a bottom layer of smaller particles during the flow. The particle discrete element method is used to simulate the flow process of binary particles, which is verified by experiments. An index to measure the effect of stratification and the separation degree (SD) are proposed. Results show that SD increases as the particle size ratio and the mass fraction of coarse particles increases. The thickness of the coarse particle layer increases as the mass fraction increases. The surface thickness and segregation are within the optimum when the particle size ratio is 2.5 and the mass fraction of coarse particles is 65%.

Liquid air energy storage (LAES) has been regarded as a large-scale electrical storage technology. In this paper, we first investigate the performance of the current LAES (termed as a baseline LAES) over a far wider range of charging pressure (1 to 21 MPa). Our analyses show that the baseline LAES could achieve an electrical round trip efficiency (eRTE) above 60% at a high charging pressure of 19 MPa. The baseline LAES, however, produces a large amount of excess heat particularly at low charging pressures with the maximum occurred at ∼1 MPa. Hence, the performance of the baseline LAES, especially at low charging pressures, is underestimated by only considering electrical energy in all the previous research. The performance of the baseline LAES with excess heat is then evaluated which gives a high eRTE even at lower charging pressures; the local maximum of 62% is achieved at ∼4 MPa. As a result of the above, a hybrid LAES system is proposed to provide cooling, heating, hot water and power. To evaluate the performance of the hybrid LAES system, three performance indicators are considered: nominal-electrical round trip efficiency (neRTE), primary energy savings and avoided carbon dioxide emissions. Our results show that the hybrid LAES can achieve a high neRTE between 52% and 76%, with the maximum at ∼5 MPa. For a given size of hybrid LAES (1 MW×8 h), the primary energy savings and avoided carbon dioxide emissions are up to 12.1 MWh and 2.3 ton, respectively. These new findings suggest, for the first time, that small-scale LAES systems could be best operated at lower charging pressures and the technologies have a great potential for applications in local decentralized micro energy networks.

A moving granular bed with a dual-layer particle structure was designed on the basis of the segregation performance of binary particle flow, and the stratification characteristics of the filter area was studied by using experiment and simulation methods. The results show that the segregation degree (SD) in the filter area is related to the inclined groove length (L) and the binary particle size ratio (γ); specifically, the SD increases with the increase in the L and the γ. When the SD reaches the maximum, a significant dual-layer particle structure appears. On this condition, the SD no longer rises with the increase in the γ or the L. When the SD reaches the maximum, the thickness percentage of the coarse particle layer in the filter area is approximately equal to the mass percentage of coarse particles in the mixed particles.

Large amounts of Chinese medicinal materials (CMMs) should be quickly dried during the harvest period because improper drying leads to a browning reaction, which deteriorates the medicinal value of...

The heat-affected zone between the layers of a weld metal is a sensitive and important component of girth welds in X80 pipelines. However, only a few studies have focused on the interlayer heat-affected zone (IHAZ). In this work, thermal simulation was conducted to investigate the relationship between IHAZ microstructure and properties. Results showed that the toughness of the weld metal improved after a single welding thermal cycle but decreased after double welding thermal cycles, particularly when the weld metal was subjected to unaltered coarse grains of IHAZ. The relationship between the microstructure and properties of IHAZ was established to present the correlation of toughness with granular bainite content, grain size, and high-angle grain boundary content. Keywords: Girth weld, Interlayer heat-affected zone, Thermal simulation, Granular bainite, Toughness

The working principle of a controllable on-demand heating system based on off-peak electricity energy storage (COHSBOEES) is as follows: the cheap off-peak electricity energy is converted into heat energy for storage in the evening, and the heat energy can be extracted on demand for heating during daytime peak or flat electricity periods. This technology can promote the smooth operation of the power grid, solve the problem of peak regulation for the electrical network, and promote renewable energy consumption. Based on the controllable on-demand heating strategy, a COHSBOEES for a heating area of 1000 m2 was designed and built. Variations in the energy consumption and operating cost of the COHSBOEES in different heating situations were analyzed. The results showed that, off-peak electricity energy storage for heating was energy saving in comparison with central heating when the heating intensity of the COHSBOEES was 70 W/m2 and the on-demand heating rate was less than 73.0%, and the off-peak electricity energy storage for heating was energy saving at any on-demand heating rate when the COHSBOEES had a heating intensity of 50 W/m2. After the COHSBOEES has been running for three complete heating seasons, when the off-peak electricity price was 0.25 yuan/kW·h, the energy consumption cost of the COHSBOEES can be saved by 77.6% in comparison with central heating.

Liquid hydrogen is the main fuel of large-scale low-temperature heavy-duty rockets, and has become the key direction of energy development in China in recent years. As an important application carrier in the large-scale storage and transportation of liquid hydrogen, liquid hydrogen cryogenic storage and transportation containers are the key equipment related to the national defense security of China’s aerospace and energy fields. Due to the low temperature of liquid hydrogen (20 K), special requirements have been put forward for the selection of materials for storage and transportation containers including the adaptability of materials in a liquid hydrogen environment, hydrogen embrittlement characteristics, mechanical properties, and thermophysical properties of liquid hydrogen temperature, which can all affect the safe and reliable design of storage and transportation containers. Therefore, it is of great practical significance to systematically master the types and properties of cryogenic materials for the development of liquid hydrogen storage and transportation containers. With the wide application of liquid hydrogen in different occasions, the requirements for storage and transportation container materials are not the same. In this paper, the types and applications of cryogenic materials commonly used in liquid hydrogen storage and transportation containers are reviewed. The effects of low-temperature on the mechanical properties of different materials are introduced. The research progress of cryogenic materials and low-temperature performance data of materials is introduced. The shortcomings in the research and application of cryogenic materials for liquid hydrogen storage and transportation containers are summarized to provide guidance for the future development of container materials. Among them, stainless steel is the most widely used cryogenic material for liquid hydrogen storage and transportation vessel, but different grades of stainless steel also have different applications, which usually need to be comprehensively considered in combination with its low temperature performance, corrosion resistance, welding performance, and other aspects. However, with the increasing demand for space liquid hydrogen storage and transportation, the research on high specific strength cryogenic materials such as aluminum alloy, titanium alloy, or composite materials is also developing. Aluminum alloy liquid hydrogen storage and transportation containers are widely used in the space field, while composite materials have significant advantages in being lightweight. Hydrogen permeation is the key bottleneck of composite storage and transportation containers. At present, there are still many technical problems that have not been solved.

This study is based on high-temperature flue gas containing condensed dust and the dust removal of granular bed. The effects of adhesion temperature, filter plate material (99% and 85% corundum), and dust materials (tin, ferric oxide, and fly ash mixed with sodium chloride) on the desorption stress of dust on the filter surface are explored through desorption stress tests. Results show that the desorption force of tin peaks at 800 °C. Adhesion at 900 °C for fly ash blended with sodium chloride. The mixture adheres on the filter surface at >800 °C, and desorption force increases as adhesion temperature and sodium chloride proportion increase. Large desorption stress occurs on the extremely rough surface of the filter material.

The impact and solidification processes of single melting tin dust at the micron scale on a spherical bead were numerically studied with hot flue gas flow. The geometrical evolution of dust impacting on hot bead and spreading without solidification involved initial spreading, retraction and oscillation, and stabilizing. The increased impact angle was found to reduce maximum spread area, weaken retraction and oscillation, and raise steady spread area. Dust impacting on cold bead completely solidified after liquid spreading and solidification without retraction and oscillation. Increased impact angle raised solidification sliding distance, whereas it reduced solidification spread area. Then, the effects of bead temperature, dust inlet velocity and size on the sliding and spreading of dust were studied, and the results indicated that increasing bead temperature, dust inlet velocity and size could raise solidification sliding distance and solidification spread area. With the dusts continually impacting on the bed, a dust layer forms at the front of bead, being different from that of solid dust, which becomes thick firstly, and then spreads from bead front to sides.

The characteristics of moisture diffusion during wheat drying were determined through low-field nuclear magnetic resonance. The feasibility of variable temperature drying was validated by identifyi...

In this work, we studied the flow characteristics of particulates in a novel moving granular bed by using experiments and numerical simulations. The new moving granular bed was equipped with one adjustable baffle and two slopes to adjust filter thickness and increase the gas-particle contacting surface. Doing so overcomes the poor adaptability and low collection rate of fine dust during the filtration, and improved the filtering performance of filter devices. In the experiment, the movement of particulates in a moving bed was recorded using a camera, and the effects of the device structure and the filter moving speed on the flow of filter particles were examined. Combined with Discrete Element Method (DEM) to simulate the velocity variation of particles in the granular bed, the mechanism of particulate flow was analyzed. The inclined surface was found to affect the flow of filter particles, and a small angle of inclination was not conducive to the particle flow. Therefore, a layer of dead particles was easily formed. The dead zone particle layers on the left slope could protect the insulation layer and the heat insulation layer outside the particle bed. Increasing the moving speed of the filter increased the velocity difference between the particles in the wall surface and the middle part. The fluidity of particles also increased to make the particle layer of dead area become thinner. The trajectory of a single particle was greatly affected by the overall moving speed, and the single particle tended to move toward the faster direction in the same plane with the increase of the filter moving speed.

A novel three-bed temperature swing adsorber was built to recover low-temperature waste heat from heat- and cold-blowing stages in a double molecular sieve of an air pre-purification system. The regenerative mass transfer in the adsorption bed was divided, and the temperature and concentration breakthrough curves of the adsorber regenerator were obtained via an experiment. Experimental results show that the relationship between the starting point and the energy of waste heat recovery is parabolic. However, energy saving reached the peak at 52.5% when the starting point of heat recovery was 23 min; this result would yield additional H2O and CO2 into the bed, thereby affecting the purification effect of the absorbers. The starting time of exhaust gas recycling for limit waste heat recovery strategy was 26 min, which resulted in 51.1% energy savings by recycling different stages of regeneration exhaust. The starting time of exhaust gas recycling for the optimal heat recovery strategy was 29 min, in which energy saving reached 46.5%. The starting time of exhaust gas recycling for the best regeneration strategy was 35 min, which generated energy saving of 29.8%.

Liquid Air Energy Storage (LAES) is one of the most promising large-scale energy storage technologies for intermittent renewable energy. The LAES includes an air liquefaction (charging) process and a power recovery (discharging) process. In the charging process, off-peak electricity is stored in the form of liquid air; meantime, a large amount of compression heat is recovered and stored at over 200 °C for later use in the discharging process to enhance the output power of air turbines. During peak times, liquid air is pumped and heated, and then expands to generate electricity in the discharging process, with cold energy of the liquid air recovered and stored to help liquefying the air in the charging process. It is well known that the recovery and utilization of both the cold and heat energy are crucial to the LAES. However, little attention is paid on the quantity and quality of the cold and heat energy. This paper carries out thermodynamic analyses on the recovered cold and heat energy based on steady-state modelling. It is found that the cold energy has a much more effect on the LAES than the heat energy; the cold energy loss leads to a decrease rate of the round trip efficiency, which is ∼7 times of that caused by the heat energy loss. In addition, the recovered cold energy from the liquid air is insufficient to cool the compressed air to the lowest temperature with the shortage of ∼18% and liquid air yield does not achieve the maximum in the charging process; external free cold sources would be needed to further increase the liquid air yield, and the round trip efficiency could easily break through 60%. Unlike the cold energy, 20–45% of the stored heat energy is in excess and cannot be efficiently used in the discharging process; we propose to use the excess heat to drive an Organic Rankine Cycle (ORC) for power generation. The ORC is considered to work at two different cold sources: the ambient and the sub-ambient. The sub-ambient cold source is generated through an Absorption Refrigeration Cycle (ARC) by consuming part of the excess heat. The combinations of the LAES and ORC with ambient and sub-ambient cold sources are denoted as LAES-ORC and LAES-ORC-ARC, respectively. Comparisons are made among the LAES, LAES-ORC and the LAES-ORC-ARC. The results show that both the LAES-ORC and LAES-ORC-ARC could achieve a much higher round trip efficiency than the LAES, with the maximum improvement of 17.6% and 13.1% under the studied conditions, respectively. It is concluded that the LAES-ORC has a simpler configuration with a better performance than the LAES-ORC-ARC configuration.

The effects of important parameters, such as moving speed, wind speed, particle layer thickness and dust particle size, on bed pressure drop and filtration efficiency of new moving granular bed filter were studied experimentally in this work, and the distribution law of collected dust was elucidated. The new granular bed filter, which adopts the moving bed continuous filtration method, has two inclined surfaces that can increase a flue gas particle contact surface and a baffle that can adjust the thickness of the filter material; thus, a high-efficiency filtration of fine dust and high performance for different environments is achieved, and the filtration characteristics of existing particulate filtration devices are improved. Experimental results show that the new moving granular bed filter demonstrates better dust removal performance than other granular layer dust collectors, thereby possibly achieving low bed resistance and high filtration efficiency and has wide adaptability. The selection of an appropriate filter medium and speed for the fine dust of 1–5 μm can maintain the filtration efficiency of the granular bed at 0.94 or more and the bed pressure drop at approximately 100 pa. The particle area with the most dust collection is on the windward side of the lower part of the granular bed, and several of the particles are replaced whilst the filter particles move. Furthermore, the dust collected by the particles in the dead zone cannot be replaced.

Liquid air energy storage (LAES) uses off-peak and/or renewable electricity to liquefy air and stores the electrical energy in the form of liquid air at approximately −196 °C. The liquefaction (charging) process involves multi-stage air compression with the heat of compression harvested by a thermal fluid, which is stored for use in the power recovery (discharging) process. When electricity is needed, the stored liquid air is pumped, heated by environmental heat first and then superheated by the heat of compression stored in the thermal fluid, and other heat sources if available, leading to the expansion of the air by over 700 times to produce power. The current LAES technology, denoted as baseline LAES in this paper, only uses the heat of compression to improve the power output in the discharging process. Our analyses show that the discharging process of the baseline LAES system cannot fully use the stored heat of compression in an efficient manner. The excess heat is in the order of ∼20–40%, mainly because the yield of liquid air lies between 0.6 and 0.78, which is significantly lower than 100%. In this paper, we propose a hybrid LAES configuration, whereby the excess heat of compression is used as a heat source to power an Organic Rankine Cycle (ORC), whereas a Vapor Compression Refrigeration Cycle (VCRC) acts as a heat sink, leading to the production of additional electricity. Thermodynamic analyses show that the newly proposed hybrid LAES system has a round-trip efficiency of 9–12% higher than the baseline LAES system. The exergy efficiency of the discharging process of the hybrid LAES system is 9.6% higher on average than that of the baseline LAES system due to the more effective use of the heat of compression. An economic analysis has also been performed using a project life span of 15 years. The results suggest that the combination of the ORC and VCRC gives a payback period of 2.7 years and a savings to investment ratio of 3.08, which are much better than the use of the single ORC.

Multi-pass welding is used in high-pressure and thick-walled pipes in natural gas and oil pipelines. When a welding layer of a welded joint is subjected to different welding thermal cycles, its microstructure and properties change, thereby affecting the overall welding performance. In this study, the temperature and microstructural variations of the fill pass 2 (FP2) in the entire welding process were investigated by combining the thermal cycle with the cascade welding method. The original FP2 and FP2 after double thermal cycles had the worse deformation ability by tensile test. The toughness of FP2 improved after a single thermal cycle, decreased after double thermal cycles, and improved again after triple thermal cycles. The content of martensite&ndash, austenite (M&ndash, A) constituents and the average grain size of FP2 in the cascade samples were inversely proportional to FP2 toughness. Massive M&ndash, A constituents and their unique distribution at the inter-critical temperature were harmful to weld metal toughness. Controlling the size and fraction of M&ndash, A constituents can improve weld metal toughness.

The energy consumption of urban central heating in northern China is two to four times that in northern Europe and other countries. Beijing has adopted measures, such as &lsquo, coal to gas&rsquo, and &lsquo, coal to electricity&rsquo, to reduce environmental pollution caused by central heating. Given a peak-to-valley difference in the electricity supply of power plant, which is uneven day and night, this study proposes to store the night-time off-peak electricity in the form of heat energy and drive the ammonia absorption system in the form of steam or hot water during peak or flat electricity. Simulation results of ammonia absorption cooling and heating dual-supply system show that heat source temperature increases, evaporation temperature increases, and cooling water temperature decreases are all beneficial to improve the refrigeration coefficient in the summer cooling condition. In the meantime, heat source temperature increases, evaporation temperature increases, and cooling water temperature decreases are beneficial for increasing the heating coefficient in the winter heating condition. The heating and cooling coefficients of the system are 1.38 and 0.65 in the optimal working condition in winter and summer. Benefit analysis shows that, compared with central heating and cold storage air conditioning, the system can save 576,000 tons of standard coal and 1.417 million tons of carbon dioxide if used in 12% of the cooling and heat supply areas in Beijing. The potential for energy saving and emission reduction is large.

In the new process of CaC2 production, C–Ca pellets need to be pyrolysed in a prepyrolysis furnace before being placed in a CaC2 furnace. In this paper, the factors influencing the performance of composite pellets in a pyrolysis furnace are studied experimentally. A comprehensive performance-evaluation system is established to calculate and evaluate composite pellets comprising five raw materials. The pyrolytic rate, compressive strength, and dust concentration of the composite pellets are tested through thermogravimetry, universal pressure tester and dust concentration detector, respectively. The effects of C/Ca ratio, temperature, time and raw material composition on these properties are explored. Results show that during the pyrolysis of the composite pellets, the C-containing raw materials have a significant effect on various performance indicators. With increased C/Ca ratio, the pellet pyrolysis rate and compressive strength show a downward trend; with increased pyrolysis temperature and time, the pellet pyrolysis rate, compressive strength and activity show an upward trend; with a change in raw material composition, the pellet activity and dust concentration change significantly. The comprehensive properties of CaO + coke and CaO + anthracite are superior to those of other raw materials in all aspects, and this finding is in line with the industrial-production practice.

The development of heat recovery methods for dry granulation processes from blast furnace slag in the iron and steel industry is limited because of the high consumption of granulation energy during these processes. To determine the factors that influence the diameter of granulated particles, a paraffin test platform for gas quenching granulation was established. The influences of air velocity, air flow rate, liquid mass flow rate, and liquid pipe diameter on the final particle size and mass distribution were studied. Experimental results showed that the final particle size decreased (from 1.07 mm to 0.81 mm) with increasing air velocity (from 28.3 m/s to 113.2 m/s). However, when air velocity was higher than 60 m/s, its influence on particle diameter decreased significantly. The experimental data were analyzed using SPSS Statistics software, which indicated that the effect of air velocity on particle diameter was the most significant, followed by those of air flow and liquid pipe diameter. The effect of liquid mass flow was the least significant.

The entrainment characteristics of fine silicon particles from solid mixtures (Geldart groups C and B) are investigated in a cylindrical fluidized bed with an inner diameter of 30 mm and a height of 450 mm and that is equipped with an agitator and an electromagnetic vibration table. Silicon particles (mean size of 2.7 μm) are used as entrained materials (group C), hollow alumina pellets (mean size of 1200 μm) are used as coarse particles (group B), and nitrogen gas is applied as carried gas. The effects of the superficial velocity of nitrogen gas at room temperature (U, 0.39 m/s to 0.98 m/s), the initial loading quantity of fine particles (M, 5 g to 20 g), the vibration intensity (Γ, 1.3 to 4.83), the stirring speed of agitator (V, 75 rpm to 195 rpm), the mass ratio of coarse to fine particles (N, 0 to 1.5), and the preheating temperature of nitrogen gas (T, 20 °C to 170 °C) on the entrainment characteristics (entrainment rate Wi and entrained powder–gas ratio R) are experimentally studied under atmospheric pressure. Significance analyses of U, M, Γ, and V are performed via the analysis of variance. M and U both significantly affect Wi, but only M significantly affects R. The experimental results show that an increase in U, M, N, and T constantly improves the entrainment characteristics, an increase in Γ deteriorates such characteristics, whereas there exists an optimal value for V to obtain the optimum entrainment characteristics. This study also determines that an optimal operating condition can result in optimal entrainment characteristics (Wi, 9.27 g/min and R, 0.19 g/g), which can be achieved with a U of 0.98 m/s, M of 20 g, Γ of 1.3, V of 155 rpm, N of 1.0, and T of 170 °C.

Simultaneous multiperiod optimization is conducted for minimizing the oxygen emission of an oxygen-distribution system, based on the generalized MILP-based model, which covers various configurations of the captive oxygen factory in integrated steel mills. By simultaneously optimizing all of the variables, such as the load of air separation units (ASU), the on-off states of compressors, the load of liquefiers, etc., the model can promptly provide mill managers with responsive solutions for adjusting the variables involved on the supply-side to minimize oxygen emission. The case study in this paper shows that the proposed model performs well in minimizing oxygen emission, and provides a global optimization result covering the entire planning horizon. Moreover, based on the proposed model, the emission amounts can be rapidly and readily calculated for various scheduling scenarios of ASU maintenance, which is helpful to the manager seeking to optimally schedule ASU maintenance in time.

Shield metal arc welding (SMAW) has been widely applied in the field of engineering. Phase change performs important functions on weld pool geometry and determines weld quality. Welding torch, which is moved or not, has important effects on the phase change of weld pool and the elements distributions, which affects the weld quality. In this paper, phase change and elements distribution of welding process with torch trace of moving without swing and with e-type swing was simulated. The results show that the geometry of the weld pool under torch trace of moving without swing transfers from initial V-type to final O-type. At the ending of welding, the width of weld pool reaches 12 mm. The distance between center of each symmetrical vortexes and the center of weld pool is 3 mm. The distribution of element C is typical double peak trends and the peak value of its component is 0.0482 % appeared at the center of vortex. Using SMAW with e-type-swing torch moving, the distance of weldment diffusion is changed. The unsteady vortex has a great influence on the phase change in the weld pool. The distribution of elements is single-peaked characteristic. At the center of weld pool, the contents of C, Si, P and S are highest, which contents are 0.050 %, 0.270 %, 0.016 % and 0.010 %, respectively. But the contents of Mn, Mo, Ni and Cr at the same position are lowest, which contents are 1.121 %, 0.063 %, 0.062 % and 0.005 %. The comparison of the simulation and experimental results showed that the error range of their solid–liquid interface geometry is 3.03–4.83 %.

A new sliding granular bed filter (SGBF), coupling the features of fixed and moving granular bed filters, was presented. An inclined granular bed was used and filter grains slid down along the inclined bed in SGBF. The grains slid fastest at bed surface and are slowed down along bed depth. According to the movement of grains, SGBF is classified as partial SGBF (P-SGBF) and whole SGBF (W-SGBF). Our results showed that P-SGBF exhibited a similar pressure drop with W-SGBF, whereas its collection efficiency was close to that of the fixed bed. The filter quality factor was adopted to estimate the performance of SGBF by coupling the effects of collection efficiency and pressure drop. P-SGBF was superior to W-SGBF and fixed granular bed filters with increasing filtration time. In addition, effects on the performance of SGBF including granular flow rate, gas velocity and inlet dust concentration were further discussed.

Fine silicon particles (mean size of 2.7 μm) are used as entrained materials, and the entrainment characteristics of fine particles are investigated in a cylindrical fluidized-bed (inner diameter of 28 mm and height of 1000 mm) under high speed airflow. The effects of the volume flow of gas (Q , 1 m3 /h to 2.5 m3 /h), the number of holes (N , 1 to 4), the size of holes (D , 1 mm to 3 mm), and the distance between holes and the upper surface of the material layer (H , -100 mm to 200 mm) on the entrainment characteristics (entrainment rate W and entrained powder-gas ratio R ) are experimentally studied through orthogonal experiment. The experimental results show that an increase in Q and H constantly improves the entrainment characteristics; a decrease in D enhances such characteristics, whereas the number of holes N has no significant effect on the entrainment characteristics. An optimal operating condition can result in optimal entrainment characteristics (W , 3.1 g/min and R , 0.058 g/g), which can be achieved with a Q of 2.5 m3 /h, N of 1, D of 2 mm and H of 200 mm.

Field synergy characteristics in condensation heat transfer with non-condensable gas (NCG) over a horizontal tube were numerically simulated. Consequently, synergy angles between velocity and pressure or temperature gradient fields, gas film layer thickness, and induced velocity and shear stress on gas–liquid interface were obtained. Results show that synergy angles between velocity and temperature gradient fields are within 73.2°–88.7° and ascend slightly with the increment in mainstream velocity and that the synergy is poor. However, the synergy angle between velocity and pressure gradient fields decreases intensively with the increase in mainstream velocity at θ ≤ 30°, thereby improving the pressure loss. As NCG mass fraction increases, the gas film layer thickness enlarges and the induced velocity and shear stress on gas–liquid interface decreases. The synergy angles between velocity and temperature gradient fields increase, and the synergy angles between velocity and pressure gradient fields change at θ = 70°, decrease at θ < 70°, and rise at θ > 70°. When the horizontal tube circumference angle increases, the synergy angles between velocity and temperature or pressure gradient fields decrease, the synergy between velocity and pressure fields enhances, and the synergy between velocity and temperature fields degrades.

Granular convection/separation of single and binary component particles are studied in a narrow vibration bed, respectively. With filling the single light particles (molecular sieve beads), the bed exhibits five different states successively by increasing the vibration frequency f from 15Hz to 70 Hz (vibration strength Γ>3), as the global convection, symmetrical heap, unsymmetrical heap, local convection and pseudo solid. Comparatively, the granular bed of the single heavy particles (steel beads) is only in pseudo solid state at the above vibration condition. By filling binary component particles (molecular sieve and same size steel beads) instead of the single component, the bed shows similar convection state with that of the single molecular sieve beads, and the heavy steel beads are aggregated in the centre of convention roll as a core. Varying the initial distribution of binary component particles, the final convection and separation are not influenced, although the aggregation process of steel beads changes.