Highest Thermal Efficiency
The main feature of Italian Scolari grain dryers is their high economic efficiency thanks to the following factors:
1) The two independent drying zones secure not only an efficient heat recovery system but also with a heat recirculation system.
2) Full insulation of dryer’s body with rock wool.
3) Ability to dry at temperatures higher than other grain dryers without damaging the grain.
All this makes it possible for the Scolari grain dryer to achieve the water evaporation energy used as low as 720 kcal/1 kg H2O, while conventional dryers need at least 820 kcal/1 kg H2O and more.
Two independent drying zones
All the key advantages of the Italian Scolari grain dryer are based on the unique two-zone drying technology. The idea is that the air is utilized in the process twice. At first the hot air from the first burner passes the lower drying zone. The exhaust air received after the lower drying zone is relatively dry and quite warm. Therefore this air is not pushed to the atmosphere. Instead, after being heated again by the second burner, it is sent to the upper drying zone, where the grain is wet and cold.
In this way the grain dryer is obtaining maximum thermal efficiency, thus securing the lowest gas consumption.
But the two-zone technology not only allows to minimize gas consumption. It also brings other advantages such as:
- The hot air temperatures in the upper and lower zones can be set independently. It allows to set a lower temperature in the lower drying zone in order to not overheat the grain.
- Grain rest zone, which is organized between the upper and lower zones, allows the grain to relieve its internal stress before entering the final stage of drying.
- Significantly lowered dust exhaust (see below for details).
Dust exhaust
Scolari grain dryers are mixed-flow dryers with completely closed air boxes. The exhaust air exits from the pipe located at the top of the grain dryer, thus minimizing overall concentration of possible dust at the work zone comparing to cross-flow dryers and mixed-flow dryers with open boxes.
Besides that Scolari grain dryers are equipped with the modern and effective dust suppression system. The principle of dust suppression system is following.
The main dust is generated by the dryer when the grain moves inside the grain column. If at this moment the air passes through the grain, it removes dust from the grain and sends it to the atmosphere. In order to prevent it, the grain dryer discharges grain by portions of 0,6-1,0 ton each. For the short period of grain discharge (5-10 seconds) the main fans are closed with special sliding gates in order to completely seal itself. After the discharge, the grain dryer opens sliding gates and drying process continues. This system reduced dust emissions to minimum levels.
Moreover, two-zone concept of the grain dryer has almost twice smaller zone of the grain column which is exposed to the exhaust pipe. So any dust may only be emitted from the upper drying zone, as shown on the picture. Any dust emitted in the lower drying zone or in the cooling zone is not exposed to the exhaust pipe and thus cannot be emitted. Instead, this air is recirculated and is sent back into the upper drying zone.
Aluzinc
The complete grain dryer column is made of Aluzinc steel. Aluzinc is a special galvanized steel which has much better rust resistance and wear resistance comparing to traditional galvanized steel.
Moreover, Aluzinc steel has a self-healing capability. Any scratches that may occur on the surface of the steel or at the edges will be self-healed with time.
Automatic moisture control
Scolari grain dryers are designed to automatically keep required dry product moisture. The grain dryer controls moisture by automatically adjusting the speed of garin (pause between the discharges of grain).
Safety
The control panel of Scolari grain dryer not only controls grain moisture, but also controls fire safety. Each column of grain dryer is equipped with 12 temperature sensors which control limit temperatures set for each grain separately. In case if a temperature at any sensor increases its limit, the grain dryer stops and issues an alarm.
Control panel also does not allow the grain to overheat. (It is known that grain overheating may lead to damage of grain).
Heat insulation
In order to minimize heat losses, the grain column and air boxes are heat insulated.
There are different grain dryers on the market. Some are not heat insulated. Some grain dryers are insulated with air layer. But the air layer does not prevent heat transfer by convection thus is not so effective.
Scolari grain dryers are heat insulated with fire resistant rockwool. Such insulation secures significant gas savings, especially in cold weather.
Soft drying
Scolari grain dryers are designed for very soft grain drying.
In case of cross-flow dryers, they remove moisture at a very high speed, up to 10% per hour. European dryers usually offer more soft drying mode for grain: 4-5% per hour.
Scolari grain dryers are even more gentle. The moisture removal speed makes 3-4% per hour while total hourly productivity of the grain dryer is the same.
This soft technology allows to save organoleptic qualities of grain and prevent grain breakage.
Our projects with Scolari grain dryers
