Ventolab® 6 Rack 51”

Ventolab® 6 Rack 51”

Experimental tobacco curing barn

Ventolab® is a special small curing barn , addressed to Universities , tobacco Research Stations & tobacco companies running curing experiments on different tobacco varieties, on different curing programs and other crops drying.
It is an indirect fired ,upflow experimental electrical barn 2 tiers high ,1 row wide , equipped with all sophisticated curing controls of the latest technology and a frequency converter (inverter) regulating the air supply to the tobacco.
It can be partially loaded with tobacco and can cure tobacco either on racks or strings .
It is equipped with single tier 51”racks (1,30m) each holding ~20 kgs green leaf min up to ~45 kgs max green leaf .
~ 2,2 m2 total rack surface in 2 tiers.
The typical 6 rack Ventolab can cure tobacco from ~ 1000 m2 plantation.
Capacity:~ 100 kgs up to ~ 250 kgs green /cure = ~ 15- 40 kgs dry leaf / cure .

Required electrical supply : 3 phase x 380 Volts + Neutral + Ground, 35 Amps main fuses.

Technical Characteristics:
Fan : Vencon FS(T) 250 Centrifugal single inlet direct driven
Fan motor : 1,5 hp – 4 poles , 3 phase ,400 Volts-50-60 Hz.
Variable Frequency Drive : Three phase 400 Volts input , 3 phase 400 Volts output.
type : LG iG5, 2 hp (400 V) 3 phase input- 3 phase output
Heat supply : 9 kW , 230 Volts Electrical resistances in 3 scales of 3 kW each scale.

Operation:
• Air supply (recirculation) to the tobacco.
Air supply can be adjusted precisely to the required level through a Variable Frequency Drive (Inverter) regulating the fan motor’s rpm.
– Turn on the fan. Fan’s rpm start rising as frequency rises from 0 Hz to the setting.
To increase or decrease the air supply to the tobacco, you have to increase or decrease fan’s rpm by turning the knob on the drive(clockwise to increase or counterclockwise to decrease the Frequency (motor’s rpm) setting on the Drive.
Note: max. allowed frequency 45 Hz (~ 1300 rpm)
min. allowed frequency 20Hz (~ 550 rpm)
Those limits as well as many other parameters are programmed in the Drive as safety limits.
If you wish for some reason to change any of the programmed safety limits read carefully Drive’s manual before attempting any parameter change.
Avoid increasing frequency over 45 Hz to avoid fan’s motor overheating.
Avoid decreasing frequency under 20 Hz to avoid overheating the electrical resistances cooled by the air stream.

• Loading green leaf.

Follow Ventobacco’s rack loading recommendations to ensure a perfect cure.
NOTE: The Ventolab curing room’s length is ~ 10 cms greater than necessary , in order to leave enough space to close the front doors when placing heavily loaded racks on the rails of the 2 tiers.
Once all racks are put in the barn, do not forget to close the remaining space next to the front doors with the supplied 2 wooden beams . ( not to allow to the air flow to bypass the leaf mass during curing.

• Checking how curing is advancing .

Ventolabs are small barns containing small amount of tobacco .
Contrary to the big curing barns where it may be hard to get rid of moisture ,on the small Ventolabs it may be hard to keep the humidity as high as required for fine coloring without using your Frequency drive.
When during curing you want to check the tobacco, shut off the fan before opening the front doors to check .
Leaving the fan running with open doors , will result fast humidity decrease in the barn.
If you already have older Ventolab barsn equipped with inspection window (2008 and older models), do not use the window to check the tobacco but shut off the fan and open the doors to check .
Leaves appearance next to the window will be a lot different than the rest of leaves in the barn.

• Heat supply to the tobacco.

Heat is supplied to the barn by electrical elements (resistances) in 3 scales of 3 kw each scale.
The on – off operation of the heating element(s) is controlled (simultaneously with the fresh air intake damper’s operation) by the Smart Curing control(computer )VK 981 (RH) with an electronic RH –W.B. dry sensor reading both Wet bulb temp.and RH% without need of wick and water.
You can turn on 1 ,2 or all 3 scales during curing .
We recommend with fully loaded barn :1 scale only on for Coloring , 2 ( or all 3) for Wilting . Leaf & Stem drying.
NOTES: When less than 1/3 of the full load , you can cure with only one scale on.
When less than 2/3 of the full load , you can cure with only two scales on.
Note:
The less scales you use to cure , the less on-off cycles you get and the smoother is the heat supply to the tobacco.
Few long operating cycles are always better than many short ones to ensure the smoothest and best possible cure.
To dry leaf & stem with only 2 scales on, greatly depends on the amount & size of green leaves in the barn & the ambient humidity and temperature of the area.
If you have a lot of tobacco in the barn and 2 scales are not enough to dry the leaf, you will notice it during the cure . Although the control will be giving the order to heat & the heating elements will be continuously on (not cycling on –off), the D.B. temperature will not be advancing or even may be falling. This means you have to turn on more kheating elements.

• Fresh air intake .
Fresh air is sucked in the barn through the servocontrolled by the VK 981 fresh air intake damper.
Damper can be manually controlled when damper’s switch on the control panel is placed in DAMPER –MAN position
By pressing servomotor’s clutch (black knob) you disengage the mechanism & you can open manually the damper.
When damper’s switch on the control panel is placed in DAMPER-AUTO position the damper operates automatically opening & closing by the servomotor.
The servomotor is progressive taking order from the Curing Computer VK 981(RH) to partially open or close the damper to allow the appropriate fresh air amount to get in the barn & reject the surplus moisture in order to keep the W.B temperature( RH%) to the required level.

• Misting system.
A water line with an orifice is mounted right under fan’s exhaust to supply water spray for conditioning the dry leaves. When stems are dry let the barn cool down and connect a water hose supplying water to this line.
Recommended pressure > 60 psi. ( > 4 bar )
Optional: a water solenoid valve can be mounted on the sprayer’s line if automatic misting is required .
For detailed information, consult the detailed VK 981(RH)TWIN Operator’s manual.

• Curing control.

Your Ventolab is equipped with our latest programmable fully automatic “Smart “Curing Control (Computer )
VK 981(RH)TWIN to control precisely the operation of the Heating elements , the fresh air damper and an optional spraying.
Curing monitoring software and the necessary hardware to transmit the signals from the curing control to your PC are supplied with the barn. The barn’s operation can be accessed from any place in the world through Internet.

VK 981 is equipped with an RS 485 data output door.
Operator can monitor curing on his P/C through a hub (modem) or through wireless transceivers and access curing from any place in the world.

Read carefully VK 981(RH) TWIN Operator’s manual to become familiar with the control and take advantage of all it’s capabilities.

Before starting your Ventolab check that you have

• appropriate Voltage: 3 phase x 400 Volts + Neutral + Ground (or other upon request)
• efficient Ground.
• properly connected the electrical supply to the barn’s electrical panel. (check el.drawing).

NOTE: the VK 981(RH) counts , keeps & displays operating hrs precisely.