Description:a continuous-type fluidized bed popping machine employing a hot air fluidization concept that is flexible enough to handle a variety of raw materials (sorghum, millets, amaranthus, rice, maize, paddy etc.) was developed. It works with a power requirement of 5 kW (440 V) and a 3-phase AC current.
Major Components of Popping Machine: (i) Heating Zone: During the heating process, a zone pipe is placed inside the ceramic muffle which is wound by a heating coil followed by a refractive cover. The heating zone heats the coil (kandhal, iron-chromium-aluminium alloy) of 2.0 mm thick, which is wounded around the SS 304 pipes by passing electricity. The air from the blower gets heated up and is transferred to the popping zone. The heating zone comprises (a) Blower: It sucks atmospheric air and passed through a hot air pipe to ensure a fluidized bed system for popping action. The diameter of the blower delivery is 90 mm radius, length and width are 240 mm and 270 mm, respectively (b) Ceramic Rectangular Mufflers: It is placed inside the heating zone. It can be operated up to temperatures of 1600 °C. (c) Conduction Pipe/Airflow Pipe: In this process, stainless steel pipes of a diameter 54 mm and a length of 509.6 mm. The metal plates are placed to increase the surface area and contact area (d) Heating Element: The air flowing from the blower is heated by using the heating coil/heating element. The hot air passes through the heated pipe in the heating zone to the popping zone. The wire/strips made of Kandhal iron-chromium-aluminium alloy (2 mm thick). The temperature range of the heating element lies between 50-1200 °C. The hot air transfers from the pipe to the delivery of the blower for popping. (ii) Popping Zone: In the popping zone, the air comes in direct contact with the grains from the bottom to the top side separated by a mesh (1 mm holes and 22 gauge thick). The used hot air after popping of millets are recirculated inside. (iii) Recirculating Zone: It consists of a recirculating pipe with a diameter of 44 mm, height and length of 894 mm, and 294 mm, respectively. The air recirculates, passing through the suction point of the blower. (iv) Control System: The control panel is used to set the heating zone and popping zone, also having on/off switches for blowers and heating coil/element temperatures. It consists of a blower switch and other two switches for increasing or decreasing the temperature. It also consists of a switch to operate the heating of the coil.
SPECIFICATION
Mode of operation : Continuous type
Overall dimension : 1000 x 970 x 580 mm
Power requirement : 5 kW (Three phase)
Capacity : 1.4-2.0 kg/h
Weight : 80 kg
Floor area : 1000 x 970 mm
Purpose : Popping of small grains including maize and rice
Working principle : Hot air fluidization
Popping effiency : 60-80 %
Labourer requirement : 01 Women labourer
Salient features : Continuous and recirculatory electric-assisted hot air fluidized millet popping machine is a Tabletop gadget. Ideal for popping sorghum, amaranthus, finger millet, kodo millet and other small grains including paddy, corn, and rice etc. It is easy for women entrepreneurs to have successful business. This initiative has a greater opportunity of bringing newer scenario of whole-grain RTE niche snack food products from millets.

PRIOR ART
There are different methods of popping/puffing used in day-to-day life such as conventional method of dry heat, sand and salt treated, hot air popping, gun puffing, popping in hot oil and by microwave heating etc. The demand for ready-to-eat food is increasing day by day and some of the snack foods such as popcorn, puffed paddy (Aralu), puffed beaten rice (Avalakki puri), and puffed rice (Murmuri) are gaining popularity in different parts of the world. Popcorn which is produced by heat expansion of maize (popcorn variety), gained popularity as a favorite snack/breakfast all over the world. Powder salt and other spices are added, mixed, and cooled before packaging.
FEW PATENTS ON POPPING MACHINES
S. No Illustration Description
1
Portable popping machine
U.S 4178843; Date: 18/12/1979; Page:1-4
An apparatus for popping corn by heated air, circulated in a cylindrical popping chamber having a vertical axis to provide a fluidized bed of swirling and circulating corn to be popped. Up on popping, popped corn are lifted upwardly by moving air and to form a column of floating corn above the popping chamber and popped corn are discharged through chamber top opening.
2
Microwave oven popcorn popper, steamer and roaster
U.S 4477705; Date:16/10/1984; Page:1-6
A cooking utensil for a microwave oven is provided comprising a shallow, generally hollow, lower cooking member defining a pyramidal-shaped cavity with an open base. A stand orients the lower cooking member in the microwave oven cavity with the open base upwardly directed to define an open top, pyramidal shaped lower heating chamber for retaining and heating popcorn kernels. Unpopped popcorn kernels are gravity biased into the apexes defined by the intersections of the sidewalls of the pyramidal-shaped heating chamber to facilitate efficient heating of the unpopped kernels. A cover is disposed over the lower cooking member comprising a deep, generally hollow, upper member defining a roughly cube-shaped cavity with one open side.
3
Hot-air popcorn machine especially with a seasoning coater
US 8,276,504 B2; Date:02/10/2012; Page:1-6
A popcorn making machine includes a main unit comprising a fan pumping air into a chamber, enclosing a heater and a foreign application priority data bowl. The bowl has sidewalls tapered downwardly with mini nozzles attached there. Hot airflows are introduced from the chamber through the mini-nozzles into the bowl tangentially to its inner Surface, forming a main hot airflow circulation. A central nozzle is mounted at the bowl's bottom, including slots, introducing additional airflows, tangential to the surface, from the chamber into the bowl.
4

Corn popping machine
US 2657627; Date:3/11/1953; Page:1-16
The construction and mode of operation of corn popping machines of coin-operated automatic machines. The insertion of a coin with the machine in its normal operating condition will pass through a cycle of operations beginning with the loading of a corn cup with raw corn, the movement of the loaded cup into a dumping position relative to a perforated popping basket reciprocating in a bath of hot cooking oil, the return of the cup to its loading position, the popping of the raw corn for a predetermined time, and the lifting of the reciprocating popping basket out of the bath to a position where the popped corn is discharged through a chute into a bag, such as disclosed.
5

Corn popping machine
U.S 2742848; Date:24/4/1956; Page:1-11
In this machine, corn popping action is effected by maintaining the batch of raw popcorn in contact with a predetermined amount of cooking oil, in the popping chamber formed by the oscillating basket, at a predetermined temperature for a predetermined popping period. For best results, a high grade hybrid type popcorn having a moisture content not less than 12% should be used. In order to pop such corn to its maximum burst or volumetric increase, without husks, and in a tenderized condition, and to secure a popped product uniform in quantity and quality regardless of the number of operating cycles and periods between operating cycles, it is essential that the amount of raw corn, cooking oil in the popping chamber, popping period, and temperature in the popping chamber, be coordinated and maintained uniform for each cycle.
6
Apparatus for popping corn
U.S 2743663; Date:1/5/1956; Page:1-10
The corn popping machine of this type utilizes hot oil or grease, which will effectively pop the corn. The use of hot oil or grease in the so-called French-frying method of popping corn, wherein a series of consecutive quantities of corn are popped by submerging the same into a common container of hot oil or the like, produces very satisfactory and uniform results at the outset.
7

Corn popping machine
U.S 2586347; Date:19/2/1952; Page:1-6
This is a corn popping machine adapted to have capacity so it may be used for commercial purposes. It is provided with an agitator for the kernels of corn, which may be formed of a half-round material or in flat strip-like form with the bottom surface of the agitator resting against the bottom of the popping kettle. The kernels of corn are evenly distributed across the bottom of the kettle and the agitator which is half-round in cross-section: acts to turn each and every kernel of corn over, as the agitator rotates in the kettle and passes under the kernels to turn them from one side to the other and in this manner distributes the heat to all sides of the kernels and thereby securing greater efficiency in the popping of the kernels in the operation.
TYPES OF POPPING/PUFFING
(i) Sand Puffing: In India, work on puffing of paddy has been carried out by Srinivas and Desikachar (1973) and standardized a laboratory procedure for preparing small puffed paddy samples by sand roasting for the purpose of evaluation. Their study revealed that maximum expansion in puffing of paddy could be achieved by using fully mature, crack-free grains having a moisture content of 14 % (wb) and roasting at an optimum sand temperature of 275 C. Chinnaswamy and Bhattacharya (1983) have reported optimum conditions for sand puffing of rice at 250 C for 2.5 min for best expansion. Chandrasekhar and Chattopadhyay (1989) reported that the hydro thermally treated rice at 10.5-11 % moisture content can be puffed in sand at 250-260 °C temperature.
(ii) Gun Puffing: Fast and Caldwell (1990) reported that the large grain size wheat preferred for puffing on account of its higher expansion during puffing, but durum wheat may also be used. The wheat is pre-treated with 4 % of a saturated brine solution (26 % salt content) to toughen the bran during preheating and make it cohesive, so that the subsequent puffing action blows the bran away from the grain, thereby improving its appearance. Explosion puffing includes initial air drying of the product to moisture content of 0.175 to 0.538 kg/kg of dry matter, heating under pressure in a steam gun and quickly releasing the pressure which causes rapid release of vaporizing moisture, resulting in expansion of the product (Hailand et al., 1977).
(iii) Microwave Popping/Puffing
The microwave popped/puffed product are well comparable with products available in market as per the sensory evaluation. The fat and ash content were least affected due to processing while protein content was found to be decreased due to oven toasting. The oil content in microwave puffed products was considerably less as compared to that in oil fried products (Dhumal 2010; Dhumal et al., 2014). Bhatt and Joshi (2014) observed that there was an improvement in the puffing quality of the rice in terms of puffing yield, volume expansion ratio and overall acceptability when the milled rice was treated with salt. As the concentration of the salt was increased from 0 to 3%, the quality parameters improved.
(iv) Fluidized Bed Popping: The fluidized bed is the concept of forming a quantity of a solid particulate substance (usually in a holding vessel) that is laced under appropriate conditions to cause the solid/fluid mixture to behave as a fluid. It increases the heat and mass transfer because of exposure of a larger surface area uniformly to the heating medium therefore, fluidized bed HTST is more efficient than hot air or conduction roasting etc. Chandrasekhar and Chattopadhyay, 1989 reported a higher expansion ratio (8.5-10) with better product colour for the process temperature range (240-270 oC) and exposure time (7 - 9.7 s). Konishi et al., 2004 mentioned that it is not only influenced by the moisture content of the grain, but also by the moisture in the heating media. Chandrasekhar and Chattopadhyay 1988 also reported that the popping time was prolonged with the decreasing air temperature and the lag time inside the column was much longer for lower air temperatures. The residence time of kernels in the column is completed on the kernel expansion. The density of the kernel quickly decreased and particles flew out of the column. The popping of rice grain took place when the surface grain temperature attained a value of around 170 oC.
Annexure I contd…

NOVELTY DUE TO INVENTION
Fluidization is known to increase the heat and mass transfer as product surface area is uniformly exposed to the heating medium, therefore, fluidized bed high-temperature short time (HTST) puffing is more efficient than hot air or conduction roasting or puffing process. A fluidized bed is formed when a quantity of a solid particulate substance is placed under appropriate conditions to cause the solid/fluid mixture to behave as a fluid. Continuous type and fluidized beds were designed and developed employing fluidization by hot air, flexible enough to handle a variety of raw materials (sorghum, pearl millet, kodo millet, finger millet etc, and other small grains including paddy, rice, and corn), efficiently yielding good texture, nutrition, and other organoleptic properties of popped millets and its consumer acceptability. Therefore, this system is designed to be more compact and insulated with insulating material for minimizing heat losses which will be more energy efficient.

Annexure I contd…

INVENTIVE STEPS

A continuous-type fluidized bed millet popping machine was designed and developed employing a hot air fluidization concept that is flexible enough to handle a variety of raw materials (sorghum, pearl millet, kodo millet, finger millet etc, and other small grains including paddy, rice, and corn). It operates with a power requirement of 5 kW (440 V & AC).

MAJOR COMPONENTS OF POPPING MACHINE

(i) Heating Zone: During the heating process, a closed air flow pipe is placed inside the ceramic muffle which is wound by a heating coil followed by a refractory cover. The heating zone heats the coil (kandhal - iron-chromium-aluminium alloy) in the thickness of 2 mm which is wounded around the SS 304 pipes by passing electricity. The air from the blower gets heated up and is transferred to the popping chamber. It comprises of Blower Ceramic Rectangular Mufflers, Conduction Pipe/Airflow Pipe 1 mm holes, and 22 gauge and Heating Element.

(ii) Popping Zone: In the popping zone, the air comes in direct contact with the grains. It produces a maximum air temperature of 142.5?. The used hot air after the popping of grain is subjected to its inside the chamber which is placed above the popping zone.

(iii) Recirculating Zone: The recirculating chamber consists of a recirculating pipe with a diameter of 44 mm, height and length of 894 mm, and 294 mm, respectively. The pipe recirculates the air and releases it into the suction side of the blower.

(iv) Control System: The control panel is used to set the temperature. It consists of (on/off) blower switch, thermostat switches adjusting the temperature and (on/off) switch to operate the heating of the coil element.

FUNCTIONING OF THE EQUIPMENT
The raw grain about 12 ± 0.2 % wb is found to be good for popping. The maximum and minimum airflow velocities are measured to be 4.925 m/s, 5.510 m/s, 0.845 m/s, and 1.385 m/s, 4.780 m/s, and 1.310 m/s at suction, delivery, and recirculatory points respectively with a volumetric flow rate of 0.010 m3/s.
, Claims:We claim the continuous and recirculatory electric-assisted hot air fluidized millet popping machine with the following claims:

1. Continuous and recirculatory electric-assisted hot air fluidized millet popping machine comprises of (i) furnace type indirect heating (ceramic muffle) chamber (Part 1, Plate 2), cemented and wound with nickel-chromium alloy electrical heating element with insulation bricks and pads, (ii) circuitous stainless (SS 304) pipe assembly housed inside the heating furnace, enables the blown atmospheric air temperature to desired hot air temperature (Part 2, Plate 2), the forced (more than terminal velocity) hot air delivery pipe leads to (iii) popping zone (Part 3, Plate 2), where continuously fed millets are popped, exploiting the sensible heat of forced hot air fluidized bed created at the bottom of the popping zone (Part 4, Plate 2), and (iv) recirculatory system provided at the top of the popping zone (Part 4, Plate 2) connecting the suction side of the air blower, thus used hot air is available for the recirculatory purpose.
2. Continuous and recirculatory electric-assisted hot air fluidized millet popping machine as claimed in claim 1 consists of furnace-type indirect heating (ceramic muffle) chamber (Part 1, Plate 2), cemented and wound with nickel-chromium alloy electrical heating element with insulation bricks and pads for 5 kW (3 Phase) to produce a heating zone of 800oC (having a maximum temperature provision up to 1100-1200 oC).
3. Continuous and recirculatory electric-assisted hot air fluidized millet popping machine as claimed in claim 1 consists of circuitous stainless (63 mm diameter, SS 304) pipe assembly (housed inside the heating furnace), enables the blown and passed through atmospheric air temperature to desired forced (>2-4 m/s, the terminal velocity of various millet) hot air temperature (140-160 oC) (Part 2, Plate 2), to deliver for popping zone.
4. Continuous and recirculatory electric-assisted hot air fluidized millet popping machine as claimed in claim 1 consists of a popping zone, where continuously fed millets are popped, exploiting the sensible heat of the forced/fluidized bed hot air created at the bottom of the popping zone (wire mesh supported) (Part 4, Plate 2).
5. Continuous and recirculatory electric-assisted hot air fluidized millet popping machine as claimed in claim 1 consists of an insulated recirculatory system, provided at the top of the popping zone (Part 4, Plate 2) connecting the suction side of the air blower, thus using the heat energy available in the used hot air for the recirculatory purpose. The suction airflow can be controlled by a baffle valve, thus the terminal velocity for various millet be managed using this continuous and recirculatory electric-assisted hot air fluidized millet popping machine for all millets.