Tobacco Curing Stations

Curing stations general info

The idea of building centralized tobacco curing stations goes back in the early 50s practiced since that time in almost all major tobacco producing countries.

It is a practice still followed in many tobacco countries where better control of curing is required.

A Tobacco Curing Station consists of an open area where several tobacco curing barns are installed close to each other in either one row or two or more rows, one row facing the other with a shaded loading area in front of each row and an access road between them.

Usually the open area is big enough to allow:

• -expansion of the size & number of installed tobacco curing barns whenever this is required &
• -possibility of constructing a warehouse for storing cured tobacco for a short or longer time.

ADVANTAGES

The main advantages of a curing station where all tobacco curing barns are gathered compared to individual tobacco barns spread around yards of different farmers are the following :

-Good control of green leaf that farmers bring to cure. The farmers are well controlled and if unripe tobacco is brought to cure, it cannot be accepted.

This practice makes farmers bring ripe tobacco which insures better quality of cured leaf.

On the contrary when farmers operate on their own it is hard to control with what kind of tobacco they are loading the barns.

-Better control of the energy supply to the curing barns.

Fuel & electrical supply to the curing barns are well controlled & a back up generator can run the whole station when electrical power goes off, ensuring that there is not going to be any quality loss because of lack of energy.

-Lower curing cost.

Centralized tobacco curing control by experienced operators and Smart tobacco curing controls saves curing time & ensures lower energy consumption both on fuel & electricity.

-Very efficient control of the curing process
Curing is followed by experienced operators ensuring the best possible cured leaf quality.

-When barns are spread to each farmer, inexperienced farmers operate on their own the barns and several times they make wrong judgments on how to operate efficiently to ensure the best curing.

-Better dry leaf quality

Tobacco curing is closely followed by experienced operators & is always better compared to curing by inexperienced farmers.

-Better grading

When tobacco leaf grading is done right after curing, right in front of the barns it is very easy to control it.

-Better tobacco storage

Cured tobacco can be kept in a controlled warehouse insuring proper storage conditions.

-Better service of the equipment

Since all tobacco curing barns are together, all spare parts are ready available in one location and one well trained technician can service them properly and right away when required.

-When curing barns are spread in the countryside it is hard to ensure efficient service.

SIZE: The size of a tobacco curing station depends on the amount of the tobacco to be cured.

It can be small with just a few barns up to big with a hundred or more barns.

HARVESTING: Green tobacco is brought to the station harvested either

-by hand or- self propelled harvesters or-tractor pulled harvesters.

CONSTRUCTION:

Barn construction can be either prefabricated in modules with metal frame and foam insulating panels with expanding possibilities, or home built with bricks & concrete or other suitable locally found material.

Home build tobacco curing barns when made according to Ventobacco’s specifications & equipped with the proper air furnaces & curing controls can cure as good as the prefabricated.

RACK & BOX BARNS :Curing station’s barns can be either rack tobacco barns or

box tobacco barns or tobacco barns designed to be retrofitted to box or rack whenever customer wants.

When tobacco is harvested :

-by hand the fastest way to load is in Rack barns.

-by automatic harvesters fastest loading is in Box barns.

SHADES : Construction of shades in front of the barns helps:

-loading green leaves-unloading cured tobacco under rain or strong sun

-prevents green fresh leaves from wilting when trucks bring tobacco leaves to the site and while leaves are racked or boxed

-facilitates grading cured leaf in front of the barns right after unloading barns.

Tobacco curing barns in a curing station run independently which gives a big advantage to the operator since every barn’s curing schedule is adapted to the specific kind of tobacco loaded in this barn.

Smart CURING CONTROL : Each barn’s “smart ” curing computer VK 981(RH) by controlling the water evaporation rate from the leaves, (besides the control of DRY bulb, WET bulb & ΔΤ) refines the curing schedule according to the specific tobacco’s conditions and curing demands.

FIRE ANY FUEL AVAILABLE:

Barns in a curing station can fire any available fuel:

-either independently with a burner and a heat exchanger on each barn (when liquid or gas fuels),

-or joined in groups supplied with hot water in their heating coils (radiators), produced in a central hot water boiler firing any liquid or gas fuel or solid fuels like coal, wood, biomass,pellets and other combustible materials either manually fed or automatically through special feeders.

Heat energy to the curing barns can be supplied centrally by using hot water heated in boilers firing locally available cheap fuel.(wood, coal, pellets and agricultural by products).

Every curing barn still runs independently.

Hot water boilers may be:

-manually fed (when wood or big coal pieces) or

-through automatic feeding mechanisms (when coal small pieces, pellets, wood chips etc.)

Hot water curing installations are designed from specialists according to client’s needs and local conditions.

Several barns can be connected on one boiler room equipped with one or more hot water boilers, water circulating pumps, inertia tanks, expansion tanks and all necessary parts to ensure efficient & sate operation etc.

EXPERIENCED DESIGN OF A TOBACCO CURING STATION :

The layout of a tobacco curing station depends basically on:

-the amount of tobacco to be cured (i.e. size & number of barns)

-the type of tobacco curing barns (rack barns, box barns)

-the way green tobacco is coming to the station (by trucks, racked or bulk etc.)

-the available space and the style of the desired curing station

-the fuel to be fired.

Different layouts are carefully designed according to customer’s specifications & green tobacco harvesting-loading practices to ensure efficient operation

Hot water installations can be extremely energy efficient….

Day’s solar energy can be stored in boilers by using solar energy to preheat the air either through:

-solar panels or

-solar barn roofs

by using air to air heat exchangers to recuperate energy lost from humid air rejection.

by using a second roof on top of the barn at a small distance made in black heat absorbant corrugated steel material. Preheated fresh air is sucked through the 2 roofs saving fuel during the day.