Apparatus for thermal gas treatment

Abstract

Apparatus for thermal gas treatment of objects carried on an endless conveyor, in particular food items, where said apparatus comprises: a housing separated in two or more sections ( 1,2 ), where a first section comprises means ( 3 ) for moving said first section in relation to a second section; an endless conveyor ( 5 ) belt arranged inside said housing and projecting outside said housing in a first and second end, where said endless conveyor has an upper run suitable to carry the objects and a lower return run; two or more gas conditioning units ( 7, 12, 13 ) arranged inside said housing, where the units are arranged one downstream of another along the conveyor, for directing a treated gas towards the endless conveyor; substantially gas tight partitions ( 8 ) separating the gas conditioning units from each other, creating separate treatment zones, where said treatment zones are only connected adjacent the endless conveyor; where said housing substantially completely encloses said gas conditioning units, partitions treatment zones and the endless conveyor except for the first and second end sections.

1 . Apparatus for thermal gas treatment of objects carried on an endless conveyor, in particular food items, where said apparatus comprises:
 a housing separated in two or more sections, where a first section comprises means for moving said first section in relation to a second section;   an endless conveyor belt arranged inside said housing and projecting outside said housing in a first and second end, where said endless conveyor has an upper run suitable to carry the objects and a lower return run;   two or more gas conditioning units arranged inside said housing, where the units are arranged one downstream of another along the conveyor, for directing a treated gas towards the endless conveyor;   substantially gas tight partitions separating the gas conditioning units from each other, creating separate treatment zones, where said treatment zones are only connected adjacent the endless conveyor;   
     where said housing substantially completely encloses said gas conditioning units, partitions treatment zones and the endless conveyor except for the first and second end sections. 
   
   
       2 . Apparatus according to  claim 1 , wherein the gas treatment of objects on the conveyor includes an impingement process, where the apparatus further, in at least one treatment zone comprises:
 a heating or cooling element, providing passage of a gas thereby allowing heat exchange with said heating or cooling element;   a fan, said fan having an intake and an outlet side;   a gas pressure distribution system connected to the outlet side of the fan or the gas conditioning units, and further comprising an upper gas distribution chamber arranged above the endless conveyor, said chamber having an upper and lower plate member, where at least part of the lower plate member is provided with impingement nozzles or apertures, and that the upper plate member, during use is substantially in engagement with one of the sections of the housing.   
   
   
       3 . Apparatus according to  claim 2 , wherein one or more channels connects the upper gas distribution chamber with one or more lower gas distribution chambers, where each channel is partly integral with a section of the housing, and where the lower gas distribution channels are arranged under the upper run of the conveyor belt, and transverse the conveyor belts travelling direction, and where an upper plate member of said lower gas distribution chamber is provided with impingement nozzles or apertures. 
   
   
       4 . Apparatus according to  claim 1 , where the apparatus is a freezer and the gas conditioning units includes an evaporator. 
   
   
       5 . Apparatus according to  claim 1 , wherein the gas treatment of objects on the conveyor includes a gas blasting process, where the apparatus further, in at least one treatment zone comprises:
 a heating or cooling element, providing passage of a gas thereby allowing heat exchange with said heating or cooling element;   a fan, said fan having an intake and an outlet side;   a gas pressure distribution system connected to the outlet side of the fan or the gas conditioning units, and further comprising an upper gas distribution chamber arranged above the endless conveyor, said chamber having an upper and lower plate member, where said plate member is provided with longitudinal relatively narrow apertures arranged transverse of the conveyor belts' travelling direction and that the upper plate member, during use is substantially in engagement with one of the sections of the housing.   
   
   
       6 . Apparatus according to  claim 5  wherein the apertures are provided with gas direction means in the shape of guide plates, where said gas direction means provides for a gas flow against or along the travel direction of the endless conveyor belt. 
   
   
       7 . Apparatus according to any of  claim 2  wherein the upper and lower horizontal plate members, are configured so that they may be removed by sliding the plates in and/or out, and be replaced by plates of the same or of a different type. 
   
   
       8 . Apparatus according to  claim 1  wherein the housing is separated horizontally, such that the endless conveyor belt, the two or more gas conditioning units, and the substantially gas tight partitions separating the gas conditioning units from each other, creating separate treatment zones are provided on a lower section of said housing, and where an upper section by means of telescoping lifting means may be elevated or lowered from or onto respectively said lower section, whereby in the lowered position the lower and upper sections enclose the apparatus apart from the first and second ends of the conveyor belt, and in the elevated position of the upper section, the endless conveyor belt, the two or more gas conditioning units, and the substantially gas tight partitions separating the gas conditioning units from each other, creating separate treatment zones are accessible for inspection, repair, service and cleaning. 
   
   
       9 . Apparatus according to  claim 1  wherein the housing sections comprises means for creating a substantially gas tight assembly, where the sections are in mutual contact. 
   
   
       10 . Apparatus according to  claim 4  wherein the evaporator is arranged for horizontal gas flow through said evaporator, and that the pressure distribution system includes a pressure distribution section downstream of the evaporator connected to the upper and lower gas distribution chambers, and that the gas after having passed the objects on the conveyor is directed to the intake side of the fan, partly along the conveyor and mainly below the lower gas distribution chambers. 
   
   
       11 . Apparatus according to  claim 4  wherein the evaporator is arranged for vertical gas flow through said evaporator, and that the pressure distribution system includes a pressure distribution section above and upstream of the evaporator, and that the upper gas distribution chamber is arranged between the evaporator and the conveyor and that lower gas distribution chambers are connected by means of channels arranged in the housing section to said upper gas distribution chamber, and that the gas after having passed the objects on the conveyor is directed to the intake side of the fan, partly along the conveyor and mainly below the lower gas distribution chambers, and along one closed side of the evaporator.