Fruit Dryer PAES 248-249:2010 Flashcards
air moving device that is used to force heated air through the mass of materials to be dried at the desired air flow rate and pressure
fan ,blower
ripened ovary or ovaries of a seed-bearing plant that are edible, usually sweet and in fleshy form
fruit
device for removing excess moisture from the fruits, generally by forced or natural convection with or without addition of heat (see Figure 1)
fruit dryer
difference between the maximum and the minimum moisture content randomly sampled after drying
moisture gradient
wherein air pressure is developed for uniform distribution of the heated air through the material to be dried.
plenum chamber
any device that is used to avoid human accident and/or damage to the parts and components of the dryer during the operation and automatically shuts-off the operation of the dryer in case of malfunction
safety device
ratio of vapor pressure of water in the product to the water vapor pressure of pure water at the same temperature.
water activity
Mechanical dryer wherein the sliced fruits in fixed volume are held in the drying chamber in batches until it reaches the desired moisture content. (see FigureS 2a, 2b and 2c)
Batch/Tunnel type
Mechanical dryer wherein fixed volume of sliced fruits are placed on perforated tray(s) in the drying chamber until it reaches the desired moisture content. (see Figure 3)
Tray/Cabinet type
This type of fruit dryer heats up the drying air by direct burning of fuel inside the heating chamber.
Fuel burning
Dryer in which the products of combustion come into direct contact with the product being dried. (see Figure 4)
Direct
Dryer in which the products of combustion do not come in contact with the products being dried. This type uses heat exchanger. (see Figure 5)
Indirect
Fruit dryer type that heats the drying air through the use of reversed refrigeration system. (see Figures 6a and 6b)
Heat pump
Source of energy which includes petroleum-based fuels (LPG and propylene).
Conventional energy
Source of energy that includes non-petroleum fuels such as biomass and solar energy.
Non-conventional energy
Fruit dryer is coupled to an indirect-fired biomass furnace where the drying air is being heated using heat exchangers. (see Figure 5)
Biomass energy
Fruit dryer is coupled to an air type solar collector where the air is being heated and ducted to the drying chamber. Air circulation can be by natural convection or by using blowers. (see Figure 7)
Solar energy
Maximum range of drying air temperature to be used in heat pump fruit dryer shall be _______.
60°C to 70°C
Air velocity inside the drying chamber of fruit dryer should be at least ____.
0.2 m/s.
Final moisture content wet basis of the fruit to be dried shall not be more than ___.
15%.
Water activity of dried fruits shall not be more than ____.
0.70 at 25 °C.
Pineapple (Sliced thickness, mm Drying Temperature, °C)
10, 60
Papayas (Sliced thickness, mm Drying Temperature, °C)
8 to 10 ,60
Mango (Sliced thickness, mm Drying Temperature, °C)
2 to 4 ,55
Banana (Sliced thickness, mm Drying Temperature, °C)
3.3 to 3.9, 54 to 57.5
Apple (Sliced thickness, mm Drying Temperature, °C)
3 ,88
Jackfruit (Sliced thickness, mm Drying Temperature, °C)
Depends on thickness of pulps
83
When drying sliced mango, appearance/color shall be moderate yellowish brown and hardness shall be in between _____.
4.4g to 6.4g
Minimum drying efficiency of the fruit dryer shall be ____
75%.
Actual performance factor shall be at least ___ of the total carnot cycle performance factor of the heat pump fruit dryer system.
70%
The noise emitted by the dryer shall not exceed ___.
92 dB(A)
volume of air in cubic meters delivered to the mass of fruits per minute
airflow rate
mean temperature of the air to be used for drying the fruit, measured at a number of points as close as practicable to its entry to the drying bed
drying air temperature
maximum capacity that the fruit dryer can removed moisture content per unit time
drying capacity
ratio of the total heat utilized to vaporize moisture in the material, to the amount of heat added to the drying air, expressed in percent
drying efficiency heat utilization efficiency
amount of water removed per unit of time, expressed in kilogram per hour
drying rate
ratio of the total heat utilized for drying, to the heat available in the fuel expressed in percent
drying system efficiency
total amount of fuel consumed divided by the total drying time
fuel consumption
total amount of heat utilized to vaporize moisture in the material, expressed in kJ/kg of water
heat utilization
weight of fruits required to fill the dryer at the initial moisture content
holding capacity load capacity
ratio of the average percent moisture content removed from the fruits, to drying time, expressed in percent per hour
moisture reduction rate
pressure build-up in the plenum chamber to maintain uniform dustribution of air flow through the sliced fruits, expressed in mmH2O
static pressure
The fruit to be used shall be single variety and the minimum moisture content shall be ___ The fruits shall be peeled and sliced before drying.
75%.
The following shall be measured at ____ intervals or as necessary.
30-minutes
Dry the sample in the oven with temperature of ____.
103 °C ± 1 °C for 24 hours.
