Direct High-Temperature Pizza Oven
1. Structure
The baking chambers are made of special high temperature stainless steel, welding points are avoided where possible and the parts are fixed in a way to allow better dilatation of the structure. The baking chambers are with legs equipped with rollers at their end which can slide on support guides following the dilatation with no tension on the frame.
2. Technical features
2.1. Baking profile/regulation
The oven is made of a series of modules about 4 m long (zones) which are repeated up to the desired length; a turbulence section can be added, where the baking is accelerated by blowing hot air directly on the product.
To obtain the amount of heat necessary to bake in the shortest time possible 3 levels of ribbon burners are inserted in the baking chambers: the first row on the top of the baking conveyor (top heat), the second one underneath the baking conveyor (bottom heat), the third one under the return of the baking conveyor (pre-heat). Pre-heating keeps the baking band at the required temperature before the product is loaded at the oven infeed thus allowing uniform and constant baking conditions during the whole baking process.
The top heat burners are placed under deflecting shields that can be easily removed, these shield are heated to the red from the flame increasing the amount of radiation going to the products and speeding up the baking process.
The oven is divided into regulation zones each with independent temperature detection and temperature setting. Each zone has also its steam extraction valve. A butterfly valve for each zone adjusts the air/gas flow to the burners, controlling the flame; each burner can be heated or switched off.
There are different configurations of the equipment supervision and burner controlling possible with different detail levels.
Steam extraction happens by means of a manual graduated dampers.
2.2. Baking surface
The Turbopizza oven comes with granite stone baking surface – classical solution for the Italian style pizza. Stone due to its physical characteristics (specific heat per kilogram) releases the heat to the product consistently and for a long time, the spot temperature under the pizza dough does not drop during the baking time and this allows, apart from better quality, a lower baking time.
2.3. User Interface/an intelligent oven
From the operator panel the supervisor can manage the baking process completely.
It is possible to put several parameters (SET-points) and verify the actual status (IS); alarms are showed with an explanation and position on the line; the maintenance page advises about maintenance status of the different components; the recipes page can memorize the baking parameters of the different products.
The oven automation level can be increased according to the customer requirements, it is actually possible to manage automatically the baking profile of the oven automatizing the heat-dampers and/or the steam extraction dampers in the different zones. In this way the operator can set up the oven for the different product types simply by choosing the correct recipe on the control panel.
Moreover, with this system it is possible to detect the product gap inside the oven and modify the baking conditions accordingly.
3. Hygiene and cleaning
The oven is equipped with collecting drawers at the infeed and as well as outfeed.
A motorized brush cleans the baking surface and is especially useful for the granite stone cleaning.
The new inspection door design allows a better access inside the oven for cleaning and maintenance purposes.
On the lower part of the oven, under the baking conveyor return, there are access hatches that allow cleaning of the lower part of the oven.
4. Some details
Turbulence
It is a baking area where hot air is blown by a blower directly on the product. The direction of air flow is adjustable (up-down/down-up). The speed of the air is adjustable. The turbulence can be switched off, in that case the baking chamber works as a “neutral” chamber.
Hydraulic tensioning of the baking surface
Hydraulic pump for mesh or chain tensioning with programmable oven start and cool down sequence.
Oven driving system
Driving motor controlled by the inverter. The motor can be postponed or epicyclical connected directly to the drive roller.
Automatic oil device for the stone plate oven chain
Programmable automatic oil device with a cogwheel and oil distribution pump. The wheel couples with the chain, in this way the oiling point is always met.
Infrared sensor to read the stone plate temperature at oven infeed
An infrared sensor at oven infeed measures the temperature of the baking surface and allows the operator to “find” the ideal temperature at oven infeed.
Dirt collecting drawers
The oven is equipped with dirt collecting drawers at the infeed and outfeed as well as underneath the baking surface.
Motorized brush
A motorized brush cleans the baking surface and is especially useful for the granite stone cleaning.
Inspection door
The new inspection door design allows a better access inside the oven for cleaning and maintenance purposes.
Extraction blowers
If required forced extraction blowers can be mounted on the hot steam extraction chimneys. They allow controlling of the steam conditions in the chambers and as well as managing the production gaps in a better way.
Product gap management
The photocell detects the product gap before it arrives to the oven, the software modifies the parameters and follows the gap to the oven discharge.
Oven in-feed and out-feed
The manufacturing of the stone plate ovens led to the construction of innovative systems to transfer the products to and from the oven surface. The conveyor at oven discharge, for instance, has a double movement: there is a gear motor that keeps the band running and another one moving the pick-up nose horizontally, thus following the stone plate polygonal profile at the oven out-feed.