Steam peeling processing system

Abstract

A pressure vessel ( 1 ) for steam treatment of product to be peeled in a steam peeling system has substantially the shape of a sphere with opposed flattened side surfaces. The pressure vessel ( 1 ) is rotatable and has at least one internal lifting feature ( 51 a , 51 b , 51 c ) for entraining and raising product relative to the axis of rotation of the pressure vessel ( 1 ) during rotation of the pressure vessel ( 1 ). The pressure vessel ( 1 ) also at least one internal region ( 53 ) which is closed-off against ingress of steam during product treatment, said region ( 53 ) defining a steam saver. The pressure vessel ( 1 ) may be incorporated in a product treatment system also including a batcher for delivery of product to be peeled. The system may provide for accelerated pressure drop on completion of a peeling operation, as well as including arrangements to minimise release of entrained solid matter and/or odours in exhaust steam. A control system enables unproductive displacement of the pressure vessel to be minimised.

1 . A pressure vessel for steam treatment of product to be peeled in a steam peeling system, the pressure vessel having substantially the shape of a sphere with opposed flattened side surfaces.  
     
     
         2 . A pressure vessel according to  claim 1 , wherein the pressure vessel is defined at least in part by two opposed dish-shaped portions engaged together along rim regions of the portions to define an enclosed interior region.  
     
     
         3 . A pressure vessel according to  claim 1 , wherein the pressure vessel is defined at least in part by two opposed dish-shaped portions welded together rim to rim to define an enclosed interior region.  
     
     
         4 . A pressure vessel according to any preceding claim, wherein the aspect ratio between a maximum diameter of the pressure vessel and a dimension of the pressure vessel between the opposed flattened side surfaces is greater than about 1.2:1.  
     
     
         5 . A pressure vessel according to  claim 4 , wherein the aspect ratio is about 2:1.  
     
     
         6 . A pressure vessel according to any preceding claim, wherein the pressure vessel is substantially symmetrical at least about an axis extending between the opposed flattened side surfaces of the pressure vessel.  
     
     
         7 . A pressure vessel according to  claim 6 , wherein the pressure vessel is rotatable about said axis of substantial symmetry.  
     
     
         8 . A steam peeling system comprising a pressure vessel according to any of  claims 1  to  7 .  
     
     
         9 . A pressure vessel for steam treatment of product to be peeled in a steam peeling system, the pressure vessel being rotatable and having at least one internal lifting feature for entraining and raising product relative to the axis of rotation of the pressure vessel during rotation of the pressure vessel.  
     
     
         10 . A pressure vessel according to any of  claims 1  to  8 , wherein the pressure vessel has at least one internal lifting feature for entraining and raising product relative to the axis of rotation of the pressure vessel during rotation of the pressure vessel.  
     
     
         11 . A pressure vessel according to  claim 9  or  claim 10 , wherein the or each internal lifting feature comprises a protrusion extending inwards from the region of an interior surface of a wall portion of the pressure vessel, substantially in the direction of the axis of rotation of the vessel.  
     
     
         12 . A pressure vessel according to  claim 11 , wherein the or each internal lifting feature extends substantially radially inwards.  
     
     
         13 . A pressure vessel according to  claim 11  or  claim 12 , wherein the or each internal lifting feature extends directly from the interior wall surface of the wall portion of the pressure vessel.  
     
     
         14 . A pressure vessel according to  claim 11  or  claim 12 , wherein the or each internal lifting feature is defined by an upstanding portion of a false floor which is spaced from the interior wall surface of the wall portion of the pressure vessel.  
     
     
         15 . A pressure vessel according to  claim 14 , wherein at least a portion of the false floor is apertured for the passage of condensate through the apertures of the false floor during use of the system, for accumulation of condensate in the region between the false floor and the interior wall surface of the wall portion of the pressure vessel.  
     
     
         16 . A pressure vessel according to  claim 15 , wherein at least a portion of the false floor is non-apertured to provide a region for at least temporary retention of condensate accumulating during rotation of the vessel.  
     
     
         17 . A pressure vessel according to  claim 15  or  claim 16 , wherein the pressure vessel is provided with means for enabling removal of condensate from the region between the false floor and the interior wall surface of the wall portion of the pressure vessel during operation of the system.  
     
     
         18 . A pressure vessel according to any of  claims 9  to  13 , wherein the or each internal lifting feature defines a closed region which is not in communication with the remainder of the interior space within the pressure vessel for the movement of gas or vapour between the closed region and the remainder of the interior space within the pressure vessel.  
     
     
         19 . A steam peeling system comprising a pressure vessel according to any of  claims 9  to  18 .  
     
     
         20 . A pressure vessel for steam treatment of product to be peeled in a steam peeling system, the pressure vessel having at least one internal region which is closed-off against ingress of steam during product treatment, said region defining a steam saver.  
     
     
         21 . A pressure vessel according to any of  claims 1  to  7 , wherein the pressure vessel has at least one internal region which is closed-off against ingress of steam during product treatment, said region defining a steam saver.  
     
     
         22 . A pressure vessel according to  claim 20  or  claim 21 , wherein said at least one internal region is defined within an enclosure, all portions of which are spaced apart from any interior wall surface of the pressure vessel.  
     
     
         23 . A pressure vessel according to  claim 20  or  claim 21 , wherein the pressure vessel is rotatable and said at least one internal region which is closed-off against ingress of steam during product treatment is defined by an internal lifting feature for entraining and raising product relative to the axis of rotation of the pressure vessel during rotation of the pressure vessel.  
     
     
         24 . A pressure vessel according to  claim 23 , wherein said internal lifting feature is provided in accordance with any of  claims 11  to  14 .  
     
     
         25 . A pressure vessel according to  claim 20  or  claim 21 , wherein said at least one internal region which is closed-off against ingress of steam during product treatment is provided on the side of a door of the pressure vessel, which side is directed towards the interior of the vessel.  
     
     
         26 . A pressure vessel according to  claim 20  or  claim 21 , wherein said at least one internal region which is closed-off against ingress of steam during product treatment is provided by an enclosure located on a wall portion of the vessel in the vicinity of an axis of symmetry of the vessel.  
     
     
         27 . A pressure vessel according to  claim 26 , wherein said enclosure is symmetrically located with respect to the said axis of symmetry of the vessel.  
     
     
         28 . A steam peeling system comprising a pressure vessel according to any of  claims 20  to  27 .  
     
     
         29 . A rotary product batching unit comprising a plurality of compartments arranged for advancing movement within an enclosing housing, for selective successive alignment of each compartment with a product loading location and subsequent alignment of the compartment with a product discharge location.  
     
     
         30 . A rotary product batching unit according to  claim 29 , wherein each compartment of the batching unit is defined between radially spaced apart and radially extending blades of vanes mounted for rotation about a common axis.  
     
     
         31 . A rotary product batching unit according to  claim 29  or  claim 30 , wherein the batching unit is mounted by way of weighing means, for computation of the weight of product accommodated by the batching unit.  
     
     
         32 . A rotary batching unit according to  claim 31 , wherein said weighing means comprises a plurality of load cells.  
     
     
         33 . A steam peeling system comprising a rotary batching unit for cooperation with a pressure vessel for steam treatment of product to be peeled, the rotary batching unit having a plurality of compartments arranged for advancing movement within an enclosing housing, for selective successive alignment of each compartment with a product loading location and subsequent alignment of the compartment with a location for discharge of product to the pressure vessel.  
     
     
         34 . A steam peeling system according to any of claims  8 ,  19  and  28 , comprising a rotary batching unit for cooperation with the pressure vessel, the rotary batching unit having a plurality of compartments arranged for advancing movement within an enclosing housing, for selective successive alignment of each compartment with a product loading location and subsequent alignment of the compartment with a location for discharge of product to the pressure vessel.  
     
     
         35 . A steam peeling system according to  claim 33  or  claim 34 , wherein each compartment of the batching unit is defined between radially spaced apart and radially extending blades or vanes mounted for rotation about a common axis.  
     
     
         36 . A steam peeling system according to any of  claims 33  to  35 , wherein the batching unit is mounted by way of weighing means, for computation of the weight of product accommodated by the batching unit.  
     
     
         37 . A steam peeling system according to  claim 36 , wherein said weighing means comprises a plurality of load cells.  
     
     
         38 . A steam peeling system comprising a pressure vessel for steam treatment of product to be peeled and an expansion chamber for receiving pressurised steam discharged from the pressure vessel at the end of a steam treatment phase of a steam peeling operation, means being provided for enabling release of pressurised steam from the pressure vessel into the expansion chamber, said means being located substantially at the point of entry of steam into the expansion vessel.  
     
     
         39 . A steam peeling system according to any of claims  8 ,  19 ,  28  and  33  to  37 , comprising an expansion chamber for receiving pressurised steam discharged from the pressure vessel at the end of a steam treatment phase of a steam peeling operation, means being provided for enabling release of pressurised steam from the pressure vessel into the expansion chamber, said means being located substantially at the point of entry of steam into the expansion vessel.  
     
     
         40 . A steam peeling system according to  claim 38  or  claim 39 , wherein the cross-sectional flow area of the pressure releasing means increases progressively through said means from an inlet region of the pressure releasing means to a discharge region of the means.  
     
     
         41 . A steam peeling system according to  claim 40 , wherein said pressure releasing means comprises a valve.  
     
     
         42 . A steam peeling system comprising a pressure vessel for steam treatment of product to be peeled, wherein pressurised steam is discharged from the pressure vessel through a port of the vessel at the end of a steam treatment phase of a steam peeling operation and the ratio between pressure vessel volume in litres and the area of said port in square inches is less than about 20:1.  
     
     
         43 . A steam peeling system according to any of claims  8 ,  19 ,  28 , and  33  to  40 , wherein pressurised steam is discharged from the pressure vessel through an exhaust port of the vessel at the end of a steam treatment phase of a steam peeling operation and the ratio between pressure vessel volume in litres and the area of said port in square inches is less than about 20:1.  
     
     
         44 . A steam peeling system according to  claim 42  or  claim 43 , wherein said port comprises the only steam exhaust port from the pressure vessel.  
     
     
         45 . A steam peeling system according to  claim 44 , wherein said pressure vessel comprises a single steam entry port.  
     
     
         46 . A steam peeling system according to any of  claims 42  to  45 , wherein steam entry and steam exhaust takes place through said port.  
     
     
         47 . A steam peeling system according to any of  claims 42  to  46 , wherein said ratio is in the range 10:1 to 20:1.  
     
     
         48 . A steam peeling system according to any of  claims 42  to  47 , wherein said ratio is about 14:1.  
     
     
         49 . A steam peeling system comprising a pressure vessel for steam treatment of product to be peeled and an expansion chamber for receiving pressurised steam discharged from the pressure vessel at the end of a steam treatment phase of a steam peeling operation, means being provided for release of steam and/or vapour from the expansion chamber to atmosphere, said means comprising an arrangement for substantially minimising release of entrained solid matter and/or odours in steam and/or vapour leaving the expansion chamber.  
     
     
         50 . A steam peeling system according to any of claims  8 ,  19 ,  28  and  33  to  48 , comprising means for release of steam and/or vapour from to atmosphere from an expansion chamber for receiving pressurised steam discharged from the pressure vessel at the end of a steam treatment phase of a steam peeling operation, said means comprising an arrangement for substantially minimising release of entrained solid matter and/or odours in steam and/or vapour leaving the expansion chamber.  
     
     
         51 . A steam peeling system according to  claim 49  or  claim 50 , wherein a baffle is located within the expansion chamber and a solids trap is located substantially at the exit location from a stack communicating between the interior of the expansion chamber and atmosphere.  
     
     
         52 . A steam peeling system according to  claim 49  or  claim 50 , wherein a solids trap is located in the interior of the expansion chamber.  
     
     
         53 . A steam peeling system comprising a control system for regulating movements of a pressure vessel for steam treatment of product to be peeled between loading and discharge dispositions of the pressure vessel through a succession of treatment stages, unproductive displacement of the pressure vessel being substantially minimised during said movements.  
     
     
         54 . A steam peeling system according to any of claims  8 ,  19 ,  28  and  33  to  52 , comprising a control system for regulating movements of the pressure vessel between loading and discharge dispositions of the pressure vessel through a succession of treatment stages, unproductive displacement of the pressure vessel being substantially minimised during said movements.  
     
     
         55 . A steam peeling system according to  claim 53  or  claim 54 , wherein the control system provides for discharge of product from the pressure vessel while the vessel is in motion during a treatment/process cycle.  
     
     
         56 . A steam peeling system according to any of  claims 53  to  55 , wherein the control system provides for opening and/or closing of a door portion of the pressure vessel while the vessel is in motion during a treatment/process cycle.  
     
     
         57 . A steam peeling system according to any of  claims 53  to  56 , wherein the pressure vessel is rotatable.  
     
     
         58 . A steam peeling system according to  claim 57 , wherein the control system provides for reversal of the direction of rotation of the pressure vessel during a treatment/process cycle.  
     
     
         59 . A steam peeling system according to  claim 58 , wherein the direction of rotation during dump or discharge of product from the pressure vessel is opposite to the direction of rotation of the pressure vessel at the start of treatment/process cycle.  
     
     
         60 . A steam peeling system according to any of  claims 53  to  59 , wherein the control system provides variation of speed of movement of the pressure vessel during a treatment/process cycle.