Stability and performance of a spouted bed in drying skimmed milk: Influence of the cone angle and air inlet device

2017 ◽  
Vol 36 (3) ◽  
pp. 341-354 ◽  
Author(s):  
Maisa T. B. Perazzini ◽  
Fábio B. Freire ◽  
Maria C. Ferreira ◽  
José T. Freire
Keyword(s):  
Cone Angle ◽  
Spouted Bed ◽  
Air Inlet ◽  
Skimmed Milk ◽  
And Performance

Experimental and Numerical Studies of Diesel Spray Evaporation and Combustion in a Gas Turbine Matrix Burner

2009 ◽  
Author(s):  
Dieter Bohn ◽  
James F. Willie ◽  
Nils Ohlendorf
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Instability ◽  
Cone Angle ◽  
Spray Angle ◽  
Test Rig ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Flow Simulations ◽  
Air Inlet

Lean gas turbine combustion instability and control is currently a subject of interest for many researchers. The motivation for running gas turbines lean is to reduce NOx emissions. For this reason gas turbine combustors are being design using the Lean Premixed Prevaporized (LPP) concept. In this concept, the liquid fuel must first be atomized, vaporized and thoroughly premixed with the oxidizer before it enters the combustion chamber. One problem that is associated with running gas turbines lean and premixed is that they are prone to combustion instability. The matrix burner test rig at the Institute of Steam and Gas Turbines at the RWTH Aachen University is no exception. This matrix burner is suitable for simulating the conditions prevailing in stationary gas turbines. Till now this burner could handle only gaseous fuel injection. It is important for gas turbines in operation to be able to handle both gaseous and liquid fuels though. This paper reports the modification of this test rig in order for it to be able to handle both gaseous and liquid primary fuels. Many design issues like the number and position of injectors, the spray angle, nozzle type, droplet size distribution, etc. were considered. Starting with the determination of the spray cone angle from measurements, CFD was used in the initial design to determine the optimum position and number of injectors from cold flow simulations. This was followed by hot flow simulations to determine the dynamic behavior of the flame first without any forcing at the air inlet and with forcing at the air inlet. The effect of the forcing on the atomization is determined and discussed.

Design, Development and Performance of Palm Waste Briquette Stove for Domestic and Industrial Usage

2009 ◽  
Vol 62-64 ◽  
pp. 717-722
Author(s):  
C.O. Ilechie ◽  
G.F. Aibangbee ◽  
S.R. Ogblechi ◽  
P.E. Amiolemhen
Keyword(s):  
Low Cost ◽  
Low Carbon Steel ◽  
Heating Surface ◽  
Low Carbon ◽  
Design Development ◽  
Fuel Wood ◽  
Air Inlet ◽  
Steel Material ◽  
And Performance ◽  
Palm Waste

A low cost heat-conserving stove that uses palm waste briquette (substitute for fuel wood) has been developed. It has a furnace size of 400mm diameter and a height of 400mm with a 90mm inner cylindrical burner. The heating surface of the stove generated about 966 kilojoules of heat. A natural draught of 6m/s (efflux velocity) was used to determine the chimney size. The stove which was designed and fabricated mostly from 3mm low carbon steel (mild steel) material can accommodate different sizes of briquette for both domestic and industrial cooking. The air inlet has a regulating duct that controls the burning of the briquette. The burning rate of the palm waste briquette using the briquette stove was estimated to be approximately 3.0kg/hr. This value was found to be lower than values obtained when the same quantity of briquette was burnt in the open air. The technology is recommended for adoption by women preparing snacks (such as roasted yam. plantain and corn) in market places and along commercial roads.

scholarly journals Development of an Innovative High-Temperature Gas Turbine Fuel Nozzle

1991 ◽  
Author(s):  
G. D. Myers ◽  
J. P. Armstrong ◽  
C. D. White ◽  
S. Clouser ◽  
R. J. Harvey
Keyword(s):  
High Temperature ◽  
Extreme Environment ◽  
Inlet Temperature ◽  
Engine Fuel ◽  
Air Inlet ◽  
Thermal Barriers ◽  
Surface Temperatures ◽  
Marine Diesel ◽  
Fuel Nozzle ◽  
And Performance

The objective of the Innovative High-Temperature Fuel Nozzle Program was to design, fabricate, and test propulsion engine fuel nozzles capable of performance despite extreme fuel and air inlet temperatures. Although a variety of both passive and active methods for reducing fuel wetted-surface temperatures were studied, simple thermal barriers were found to offer the best combination of operability, cycle flexibility, and performance. A separate nozzle material study examined several nonmetallics and coating schemes for evidence of passivating or catalytic tendencies. Two pilotless airblast nozzles were developed by employing finite-element modeling to optimize thermal barriers in the stem and tip. Operability of these prototypes was compared to a current state-of-the-art piloted, prefilming airblast nozzle, both on the spray bench and through testing in a can-type combustor. The three nozzles were then equipped with internal thermocouples and operated at 1600F air inlet temperature while injecting marine diesel fuel heated to 350F. Measured and predicted internal temperatures as a function of fuel flow rate were compared. Results show that the thermal barrier systems dramatically reduced wetted-surface temperatures and the potential for coke fouling, even in an extreme environment.

Air Inlet Vortex Flow and Performance of Diesel Engine

1967 ◽  
Vol 70 (586) ◽  
pp. 1631-1641
Author(s):  
Takeshi YOSHIDA ◽  
Hideichi KUROHATA
Keyword(s):  
Diesel Engine ◽  
Vortex Flow ◽  
Air Inlet ◽  
And Performance

Development of an Innovative High-Temperature Gas Turbine Fuel Nozzle

1992 ◽  
Vol 114 (2) ◽  
pp. 401-408 ◽  
Author(s):  
G. D. Myers ◽  
J. P. Armstrong ◽  
C. D. White ◽  
S. Clouser ◽  
R. J. Harvey
Keyword(s):  
High Temperature ◽  
Extreme Environment ◽  
Inlet Temperature ◽  
Engine Fuel ◽  
Air Inlet ◽  
Thermal Barriers ◽  
Surface Temperatures ◽  
Marine Diesel ◽  
Fuel Nozzle ◽  
And Performance

The objective of the innovative high-temperature fuel nozzle program was to design, fabricate, and test propulsion engine fuel nozzles capable of performance despite extreme fuel and air inlet temperatures. Although a variety of both passive and active methods for reducing fuel wetted-surface temperatures were studied, simple thermal barriers were found to offer the best combination of operability, cycle flexibility, and performance. A separate nozzle material study examined several nonmetallics and coating schemes for evidence of passivating or catalytic tendencies. Two pilotless airblast nozzles were developed by employing finite-element modeling to optimize thermal barriers in the stem and tip. Operability of these prototypes was compared to a current state-of-the art piloted, prefliming airblast nozzle, both on the spray bench and through testing in a can-type combustor. The three nozzles were then equipped with internal thermocouples and operated at 1600°F air inlet temperature while injecting marine diesel fuel heated to 350°F. Measured and predicted internal temperatures as a function of fuel flow rate were compared. Results show that the thermal barrier systems dramatically reduced wetted-surface temperatures and the potential for coke fouling, even in an extreme environment.

Design and Performance Analysis of Mixed Flow Turbine Rotors With Extended Blade Chord

2019 ◽  
Author(s):  
Thomas Leonard ◽  
Stephen Spence ◽  
Dietmar Filsinger ◽  
Andre Starke
Keyword(s):  
Transient Response ◽  
Mechanical Performance ◽  
Cone Angle ◽  
Chord Length ◽  
Blade Angle ◽  
Peak Efficiency ◽  
Mixed Flow ◽  
Blade Thickness ◽  
Turbine Rotors ◽  
And Performance

Abstract Mixed flow turbines offer additional design freedom compared with conventional radial turbines. This is useful in the automotive turbocharger application to reduce rotor inertia, which can be very beneficial for the transient response of a highly-boosted downsized passenger car powertrain. A previously published study from the authors analysed a series of nine mixed flow turbine rotors with varying blade cone angle and inlet blade angle. This paper reports an extension of that study with two further mixed flow turbine rotors where the chord length of the rotor blade was extended. The aim of this work was to understand both the aerodynamic and mechanical impacts of varying the chord length, particularly for the turbocharger application where off-design performance and transient response are very important. The baseline mixed flow rotor for this study had a blade cone angle of 30° and an inlet blade angle of 30°. Two further variations were produced; one with the TE extended in the downstream direction across the entire blade span. In the second variation the chord was extended at the hub corner only, while the shroud corner of the TE remained unchanged, with the aim of achieving some aerodynamic improvement while meeting mechanical requirements. When the blade was extended at both the hub and shroud, the inertia and stress levels increased significantly and the blade eigenfrequencies reduced. There was significant improvement in peak efficiency, but the mechanical performance was unfavourable. The improvement in peak efficiency was mainly due to better exhaust diffuser performance and therefore would not be realised in most turbocharger installations. The blade that was extended at only the hub corner incurred very little additional inertia, and the centrifugal stresses and blade eigenfrequencies were improved. Consequently, it was possible to reduce the blade thickness at the TE in order to achieve a more aerodynamically optimised design. In this case, the mechanical performance was acceptable and there were efficiency improvements of up to 1.1% pts at off-design conditions, with no reduction in peak efficiency or maximum mass flow rate. Therefore, the blade that was extended only at the hub produced some improvement within acceptable mechanical limits. The flow field features were considered for the three rotor geometries to explain the changes in loss and efficiency across the operating range.

scholarly journals Design Evaluation and Performance Analysis of a Double-Row Pneumatic Precision Metering Device for Brassica chinensis

2021 ◽  
Vol 13 (3) ◽  
pp. 1374
Author(s):  
Bohong Li ◽  
Riaz Ahmad ◽  
Xindan Qi ◽  
Hua Li ◽  
Samuel Mbugua Nyambura ◽  
...  
Keyword(s):  
Influencing Factors ◽  
Parameter Optimization ◽  
Cone Angle ◽  
Seed Mass ◽  
Single Factor ◽  
Double Row ◽  
Brassica Chinensis ◽  
Key Dimensions ◽  
And Performance ◽  
Total Seed

In view of the low seeding efficiency and precision of seeders used for Brassica chinensis in China, a new double-row pneumatic precision metering device for Brassica chinensis was designed, fabricated, and evaluated. With the characteristics of small size and high sphericity of Brassica chinensis seeds in mind, the structure and key dimensions of the metering plate were determined, and a force analysis of the seed-filling process was carried out. The negative pressure (NP), angular velocity (AV) of the metering plate, and cone angle (CA) of the suction hole were selected as the main influencing factors of the experiment. In order to explore the influence of each single factor and the interaction between factors on the seeding performance, a single factor experiment and a central composite design (CCD) experiment were designed, respectively, and the experimental results were analyzed by analysis of variance (ANOVA). After optimizing the main influencing factors such that the target of the qualified index (QI) was greater than 94% and the miss index (MI) was less than 2.5%, it was found that when CA was 60°, NP was 1.55–1.72 kPa, and AV was 1.1–1.9 rad/s, the seeding performance was excellent. The bench verification results of seeding performance (94% ≤ Q ≤ 100%, 0 ≤ M ≤ 2.5%) and the coefficient of variation (CV) of seed mass (CV of seed mass in outer and inner circle: 5.15%; CV of total seed mass: 8.60%) under the condition of parameter optimization were analyzed; as a result, the accuracy of the parameter optimization was confirmed.

scholarly journals Design and Construction of Indirect Solar Coffee Dryer

2020 ◽  
Vol 9 (4) ◽  
pp. 2943-2956
Keyword(s):  
Solar Collector ◽  
Air Inlet ◽  
Solar Dryer ◽  
Sunshine Hours ◽  
Inlet Hole ◽  
Outlet Hole ◽  
Collector Efficiency ◽  
And Performance ◽  
Drying Chamber ◽  
Design Construction

Drying is the process of removing moisture contents from solid. Solar drying refers to a technique that utilizes incident solar radiation to convert it into thermal energy required for drying purposes. This project presents the design, construction and performance of an indirect type solar dryer for coffee product. In the dryer the air inters into the solar collector from the atmosphere through air inlet hole. This air will be heated in the collector and then pass to the drying chamber through the hole. Then the air exhausts through the outlet hole at the top of the drying chamber. The system designed can handle a capacity of up to 50kg of wet coffee per m2 at a depth of 100 mm. The average sunshine at Bale Robe was found to be 12 hours per day. The daily solar insolation at the site was found to be 5.86kW/m2 of surface per day. By utilizing the solar collector in question and assuming a collector efficiency of 20 %, the total solar energy received is 5.86 kW-hrs/m2 /day or 46.88 kW-hours per day (assuming the sunshine hours per day to be 8 hours). This solar dryer has a collector efficiency of 39.1%, a pick-up efficiency of 49.3%, and a system efficiency of 32.2%. the collector area of the system is calculated to be 1.11m2 and the total length of 1000mm by 300mm. The drying chamber is essentially a cabinetry dryer and measures 1020mm × 800mm × 30mm. It accommodates a drying bin which acts as the holding compartment for the wet coffee to be dried. The base of the drying chamber is made of a block of wood material 50mm deep, since wood is a good thermal insulator. The wood must be well seasoned and pre-treated to ensure it is protected from the humid environment. The air outlet is fitted at the top of the drying chamber which serves as the exit for the moisture ridden air. It is important since it ensures that moisture does not condense at the top of the drying chamber and speeds up the rate of drying through creating the suction effect. The drying bin measures 800mm × 800mm × 20mm.

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