Step-Tower Proofer
1. Structure
The proofers are made of stainless steel pipes. To make cleaning and maintenance operations easier all the proofers are provided with internal side corridors, on the ground and overhead, with access doors on both sides.
The conditioning unit is located on a platform, which is accessible by means of a stairway.
Completely insulated, insulation panel stands on the ground or, in case of "L" proofer, on the elevated platform.
This type of proofer normally has the classic box shape and in the middle is provided with a tunnel to cross it laterally.
2. Product conveying system
Includes:
One or more ascending towers and one or more descending towers. Once arrived at the top on the ascending towers trays are shifted to the descending towers by stair-step shifter. Each tower can be bypassed. Under the tower conveyor belts position pans or trays to be taken (infeed) and receive the line of pans which is deposited at the end of proofing (outfeed).
The pans/trays are supported by 2 brackets, one on each side, attached to a pair of chains driven by an irreversible gear motor with a driving shaft. The motor moves the pair of driving shafts with toothed wheels around which the chains run and lift at one step at a time the line of pans/tray. Equally and with reverse motion the line of pans/trays is lowered at one step at a time towards the outfeed.
In case of proofers with large dimensions driving motors can be connected in electrical system.
The wheels around which the chain runs are made of hardened steel and attached to the driving shafts of the chain driving system, while the transmission wheels positioned at the bottom of the tower are idle. The idle wheels include also the chain tensioning performed by gravity.
3. Trays/pans support
The product support is performed by a pair of stainless steel brackets, which can hold a various number of pans/trays.
4. Air conditioning, air distribution and insulation
Alitech supplies the conditioning unit with the air conveying and return system (ducting), designed to meet the requirements of the final product technology.
The conditioning unit is controlled by a PLC with indication of the set and actual parameters.
Air distribution sleeves made of antibacterial inflatable fabric are used inside the proofer, they can be easily removed and washed.
The insulation of the proofer is made of sandwich type panels with both sides in stainless steel; the panels are self-carrying and arrive to the ground being slightly separated from the proofer frame to avoid dirt accumulation.
5. Maintenance, accessibility, hygiene
Although the different proofer types have different specifications what they have in common is the possibility of easy access to all the points inside the proofer that need maintenance or control.
The proofers are fitted with side corridors between the external panels and the frame, the corridors are under bottom and at the top part of the proofer, they are lighted by neon lamps and are served by access doors.
The product carriers that travel inside the proofer are also accessible and are kept high from the floor to facilitate cleaning operations.
In case of chains with oil, the lubrication can be scheduled by means of a distribution pump. The bearings of the toothed wheels are lubrication-free.
6. Control
The operating system is designed like a graphic representation of the proofer with set-points, alarms and status of the different parameters. The information on the panel available to the operator and to the plant management is scalable to provide, for example, scheduled maintenance tables, productivity and energetic efficiency diagrams and coefficients.
Our aim is to present to the supervisor all the main parameters to manage and control the line at the same time reducing as much as possible the human presence on the machine side.