GB2172495A - Dough provers - Google Patents

Abstract

A steamer unit for use in a dough prover comprises a water tank 11 having a water inlet 12 and at least one steam outlet 13, the tank being shaped as a panel having radiator side walls 19 of large surface area, and bottom 34 and end walls of small surface area, a heater 14 disposed to heat its interior space, with the steam outlet or outlets being disposed in communication with an upper portion of the interior of the tank. The units can be used singly or as an assembly of units. In addition there is provided heating apparatus comprising a steamer unit together with a second heating element associated with the steamer unit tank but mounted outside of the tank and/or one or more power control means, as well as a dough prover including one or more steamer units or assemblies of units (Fig. 4). <IMAGE>

Description

SPECIFICATION Dough provers The present invention relates to dough provers and, in particular, to a steamer unit for use in a dough prover.

In the baking of bread and other dough productsthe moulded dough is taken through a proving stage. In that stage, the dough is preferably held at a temperature ofupto about40"C and in an atmosphere having a humidity of 85 to 90 to permit the dough to rise. After proving the dough isthen baked.

Dough provers in current use are generally of two kinds. Of a first kind is a so-called "mobile" prover comprising a cabinet having a plurality of built-in trays in a racked arrangement and including at its base a shallow open-topped tank. The tank includes a heating element and in use is filled with water so that steam can be produced when the element is activated.

Of a second kind if a prover for use as part of a rack system. Such a prover comprises a cabinet without racked trays, butwhich can accommodate a mobile rack trolley comprising a plurality of racked trays, and which includes a steamer unit disposed outside the cabinet and usuallyatoronthe upper surface of its top wall. By disposing the steamer unit outside the cabinet the prover can provide the maximum space to accommodate the mobile rack trolley, and movement ofthe racktrolley into and out of the prover is not impeded.

Ofthe above-mentioned two kinds of prover, the mobile prover is less expensive to run than the second kind of prover because heat is produced within the prover cabinet. However, the second kind of prover is moreconvenientto use in that it can be part an overall rack system using a mobile racktrolleyon which the mou Ided dough products are carried disposed on its trays, both for proving in the prover, and for baking in a rack oven. On the other hand, to use the steamer unit ofthe mobile prover in the second kind of proverwould make that prover unsuitable for use with a mobile racktrolley because it would impede the movement of the rack trolley and prevent it entering the cabinet.

We have now found surprisingly that a steamer unit, particularly for use within a prover which can accommodate a rack troliey, can be provided by basing the unit on a panel-shaped watertank having radiator side walls of large surface area, and bottom and end walls of small surface area, whereby the unit can be disposed adjacent a side or end wall within a prover cabinetwithouttaking up space which might otherwise accommodate one or more racked trays and without impeding entry or exit of a rack system trolley.

Accordingly, the present invention provides a steamer unit for use in a dough prover, which unit comprises a watertank having a water inlet and at least one steam outlet, the tank being shaped as a panel having radiatorsidewallsoflargesurfacearea, and bottom and end walls ofsmall surface area, and the tank including a heater disposed to heat its interior space, with the steam outlet or outlets being disposed in communication with an upper portion ofthe interior ofthetank.

The steamer unit of the invention in one embodiment may preferably include a water level sensor and a water inlet control valve, the sensor and valve being arranged to permitthe sensor to operate the valve to top upthetankwithwaterwhen in use. Thus, in one embodiment, the tank may include a water outlet disposed in communication with a lower portion of the interior of the tank and connected to a pressuresensitive switch whereby as the water level in the tank drops in use the switch at set pressures can operate the water inlet control valve to open and close it. In any such arrangements the control valve is preferably a solenoid valve and the pressure-sensitive switch is preferably operable by air pressure.

More preferably, however, in another embodiment the water inlet of the tank is connected to a master container itself adapted to supply water on demand.

Such a master container is preferably arranged a feed water under gravity to the tankthrough its water inlet, for example, via an inlet into a lower portion ofthe tank. The level of water in the master container, and hence the level in the tank, can then be controlled by a switch e.g. a float switch, set, for example, to say an about 1 inch (25 mm) water level variation. Once again the floatorother switch can be arranged to operate the water inlet control valve e.g. a solenoid valve, this time in the water feed line from a remote water source to the master container.

Furthermore, in the steamer unit ofthe invention the heater preferably comprises a heating element disposed in at least one sealed tube passing through the tank in a lower portion thereof. More preferably, the heater comprises a pair of said tubes housing a hairpin-shaped heating element.

In the steamer unit ofthe invention, the steam outlet or outlets may be disposed in an upper portion of one radiator sidewall ofthetank. Additionally or alterna- tively, the steam outlet or outlets may communicate with the interior ofthetankthrough an upper portion of at least one end wall. In that alternative embodiment, the steam outlet or outlets are preferably formed in atubeconnectedtothetankthrough an end wall ofthetank.

Preferably, however, in a further embodiment the tank has an open top to provide the necessary outlet.

In thatfurther embodiment the tank is preferably associated with an arrangement adapted to deflect steam exiting from the top ofthe tank so that it is directed down at least one radiator sidewall of large surface area before being dispersed in the prover.

Such a deflector arrangement may comprise a deflec tor shield shaped to fit around the top of thetank and to depend down at least part of said at least one side wall. Furthermore, such a deflector shield may de pend down the whole of each said side wall and may itself include a plurality of steam outlets.

The steamer unit of the invention may be used as a single unit or as an assembly of units, depending on the energy output required and, for each of the above embodiments, the single unit may be any one unit as defined. However, for the said alternative embodimentthe single unit is preferably one wherein steam outlets are formed in each of two tubes connected to the tank one th rough each ofthe opposed end walls of the tank. In addition, a plurality of shields may be associated together in a deflector assembly for use with an assembly of units.

In an assembly of steamer units according to the invention,the assembly may comprise a plurality of steamer units as defined above in which their respective tanks are connected, in their lower portions, to provide a sealed path for water between them.

Typically, such an assembly may comprise two of four steamer units according to the invention.

Alternatively, and preferably, an assembly of steamer units comprises at least two units e.g. two, three, four or six units, each associated with a single master container arranged to feed water under gravity either directly orindirectlyto said units.Thus,alloftheunits may be fed direct from the master container orsome may be fed direct and others may be fed from a unit which itself is directly fed,for example, by connecting the tanks of such units in their lower portions to provide a sealed path for water between them.

Furthermore, the invention provides and includes heating apparatus, which apparatus comprises a steamer unit as defined above or an assembly as defined above,togetherwith a second heating element associated with the or each steamer unittank but mounted outside of the tank, preferably beneath the tank, and/or one or more power control means.

Preferably, however, such apparatus includes both the said heating element(s) and the said power control means and comprises a first control means to control the powerfed to the heateror heaters withinthe steamer unittank ortanks, a second control meansto control the powerfed to the heating element or elements outside the steamer unittank ortanks and a thermostat overall to control the power fed to the heater(s) and heating element(s) on a temRerature basis.

Typically, the first and second power control means may be open loop controls operable on a power basis, for example, those known as simmerstats. Also, the overall humidity produced by the steamer unit or units may be controlled by a humidity stat, typically one associated with the first power control means.

In addition, the invention includes a dough prover including a steamer unit as defined above, an assembly of units as defined above, or heating apparatus as defined above. Typically such a prover may comprise a cabinet accessible through one or more vertically hung doors, and may include one or more racked trays or be adapted to accommodate a rack trolley.

Furthermore, the cabinet may be one which is adapted both to store and prove dough. In that respect, the cabinet may be one which includes means to refrigerate the cabinet as well as a unit, assembly or apparatus as defined above.

Steamer units in accordance with the invention and various arrangements thereof within a rack prover will now be described by way of example with reference to the accompanying drawings in which: Figure lisa perspective view of one form of steamer unit in accordance with the invention; Figure 2 is a diagrammatic representation of controls shown associated with a steam unit as shown in Figures; Figure 3 is a plan view of anotherform of steamer unit in accordance with the invention; Figure 4 is a perspective view of yet anotherform of steamer unit in accordance with the invention; Figure 5 is a diagrammatic cross-section viewed from above showing steamer units disposed within a "single rack" prover; Figure 6 is a diagrammatic representation of controls shown associated with the watertank of Figure 5;; Figure7 is a side view of part ofthe deflector assembly outlined in FigureS; Figure 8 is an end view of a steamer unit and part of the deflector assembly outlined in Figure 5; Figure 9 is a diagrammatic cross-section viewed from above showing a "double rack" prover including three steamer units in accordance with the invention; and Figure loins a diagrammatic cross-section viewed from above showing a "four rack" prover including six steamer units in accordance with the invention.

Referring to the drawings, the steamer unit of Figure 1 comprises a generally rectangularwatertank 11 having a water inlet 12 and foursteam outlets 13. In its lower halfthetank 11 includes a heater 14 comprising a pairoftubes 15 and 16, for example, formed of stainless steel, providing a sealed path through the tank 11 and housing a "hairpin" electrical heating element 17 disposed in the tubes 15 and 16. Below the tube 16 is a small bore water outlet 18, andthetank 11 has opposed radiatorwalls 19 of which onlythefront wall is shown.

Turning nowto Figure 2, as there shown the outlet 18 is connected to an air-operable pressure switch 21, which in turn controls a solenoid valve 22 associated with a waterfeed line 23 connected to water inlet 12. In addition, the pressure switch 21 is associated with a power-operable simmerstat 24 connected to element 17, which can be set to providethenecessary simmering conditions within the tank 11 when the unit is in operation. Also, the steamer unit includes or is associated with a "dry" heating element 25 disposed beneath the tank 11 so as to provide dry heatwithin a prover, which in its turn is connected to a poweroperable simmerstat 26 which can be set to control the "dry" heat produced by element 25. Furthermore, there is a thermostat 27 associated with both simmerstat 24 and simmerstat 26 which can be setto control the overall (orcombined)"dry"and"wet"tempera- ture ofthe prover in which the unit is to be employed.

As mentioned in the introduction above, the "dry" and "wet" heat conditions should preferably be set to provide a temperature up to about e.g. about 35"C, and an atmosphere having a humidity of from 85 to 90. In addition, if desired the simmerstat 24 may be associated with a humidity stat (not shown) to provide fine control over humidity.

In practice, the tank 11 may conveniently have a depth "d", i.e. a distance between radiatorwalls 19, of about 1 inch (25 mm). Furthermore, the height "h" of the tank may conveniently be about 9 inches (225 mm) and the overall tank length "1" conveniently may be from about 18to 24 inches (450 to 600 mm). Thus, the total tank capacity will conveniently be of the order of less than about 200 cubic inches (about 3280cm3) and, because the tank capacity is relatively small, the element 17 can be a low rated element of say from about 0.2 to about 1 kw e.g. from about 0.3 to about 0.75 typically 400 w. Such a low rated element will produce a "gentle" steam ideal for proving under conditions such as those mentioned above.

Furthermore, the proverconditions produced by the steamer unit can be kept relatively stable by arranging the pressure switch 21 so that it is set to operate the water control solenoid valve 22 when the level in the tankdrops by between 2to3 inches (50to75 mm) below the maximum water level 31. Of course, the switch 21 is also always set so thatthe maximum level 31 is such as to cause no escape ofwaterthrough steam outlets 13 either by overflowing or boiling over through the outlets. Typically, where the tank 11 has an overall heightofabout9inches(225mm)the maximum water level 31 will be about5 inches (125 mm) and the minimum water level 32 will be about 2 inches (50 mm).

As will be appreciated, because the steamer unit has such a shallow depth it can be positioned atthe rear or to one side within a prover cabinet without significant- ly reducing the space within the cabinet or impeding entry to or exit from the cabinet. The steamer unit can be free standing e.g. it can stand on the floor of the prover cabinet, or it can be mounted at any desired and convenient height within the prover cabinet.

In addition, the steamer unit can be used in association with one or more "dry" heating elements which can be included to supplement the energy input necessary for any particular prover capacity. Also, for larger capacity provers whose humidity and/or energy requirements are not satisfied by a single steamer unit (with or with out one or more associated "dry" heating elements) a plurality of such units may be provided.

Forthat purpose, the tank 11 may include one or more pipes 33, preferably disposed adjacent base wall 34 of the tank, wherebythe tanks may be connected together and thetotality of connected units can be controlled by a single switch 21.

Referring to Figure 3, that shows an alternative steamer unit in which in place of (of even in addtion to) steam outlets 13 in radiator wall 19, there are provided L-shaped steam tubes 35 and 36. Again, however, each steam tube includes a plurality of steam outlets 37.

Referring nowto Figure 4, that shows yet another steamerunitsimilartothatshown in Figure 1 except thatthewaterinlet 12' entersthetankata lower position and the steam outlets 13 are omitted. Instead the tank has an open top 51 and is associated with a steam deflector assembly 52 shown in Figures 5,7 and 8, and described more fully below with reference to those Figures. In addition,thewateroutlet 18 is omitted and the level of water in the tank is controlled byfeedingthetankfrom a mastertank53shown in Figures 5and 6 and again described morefully below with reference to those Figures. Also end walls 54 and 55 ofthe unit have depending supports 56 and 57 through which "dry" heat element 25' is mounted.

Each such element may (as described above) have a capacity preferably of from about 0.4to about 0.5kw.

Referring to Figures 5 and 6,two units such as those shown in Figure 4 may be disposed in a prover cabinet 41 (Figure 5) having a door42, side walls 43 and 44, and a rearendwall 45. As shown the cabinet includes a "single rack" 46 which may comprise any suitable number of racked trays disposed one above the other, eitherfixed within the cabinet 41 or as part of a rack trolley movable into and outofthecabinet41, but which always is of "single rack" dimensions in plan.

Typically, such a rack arrangement may comprise 10 to 24trays, ofwhich only one tray is shown.

In the arrangement shown, the tank 11 of each unit is disposed adjacent a sidewall 43,44 of the cabinet 41.

In addition, each tank 11 is connected through its inlet 12' to a water feed pipe 58,59 from a master tank 53.

As shown in Figure 6, the tank 53 includes a working water level float switch 62 operable to a working water level 31' plus or minus about 1 inch (25 mm) and an emergency float switch 63 operable to an overflow level, and set as desired. The float switch 62 controls a solenoid or like valve 22' which in its turn controls the water feed to tank 53 via waterfeed lines 64,65. Also, float switch 63 controls a safety switch 66 which can cut out interalia valve 22' as necessary and prevent further supply ofwaterto tank 53.

Referring nowto Figures7 and 8, the deflector assembly 52 shown generally by a dashed line in FigureS comprises two deflector shield portions 67 each disposed around a tank 11 as shown in Figure 8.

Each shield portion 67 comprises a deflector plate 68 including a plurality of steam outlets 69 and an upper "L" shapedflange71 including screw holes 72 so that the overall assembly can be screw fixed to the prover walls via screws 73, for example, as shown in Figure 8 with reference to wall 43. Steam exiting from the open top 51 of each tank 11 is then deflected by flange 71 and portion 67 down the wall 19 and exits into the prover via steam outlets 69 as shown by dashed lines in Figure 8. Alternatively, the shield portion may be shortened and the outlets 69 may be omitted.

At their respective ends 74,75 (as shown in Figure 5) the shield portions 67 are in the assembly 52 joined to a plain end plate 76. The plate 76 serves to protect the tank 53 and its associated pipes 58,59 and to strengthen the assembly 52 overall. In addition, the plate 76 may include a rubber buffer to cushion any impact when the rack 46 is pushed into the prover (not shown) and, in that situation too, the deflector assembly overall assists in protecting the tanks 11 etc.

Also, to provide additional strength the assembly 52 may be supported at its extreme ends 77,78 by pillars 79,81 at the entrancetothe prover cabinet41.

Referring now to Figures 9 and 10, those show the manner in which "double rack" and "four rack" arrangements may be provided. In those arrangements, as with the arrangement of FigureS, the number of racks isthe number shown in the plan view (whateverthe numberof racked trays in any superimposed series), and the arrangements are based on a plurality of connected steamer units similarto that of Figure 4. However, unlike the arrangement of Figure 5, there are also in eachofthe arrangements shown central units comprising tanks 11 and a central supporting pillar 82.

Thus, in the arrangement shown in Figure 9, there are three steamer units 101 to 103 ofthe kind shown in Figure 4, each respectively disposed along cabinet side walls 43' and 44' and at the centre ofthe cabinet.

The tanks 11 of each unit are each connected via their inlets 12' and pipes 58', 59' and 104to a single master tank 53' disposed adjacent end wall 45'. In that manner a single tank 53' may be used to supply water to the assembly oftanks 11. Also, so that racks 105 and 106 may be moved independently into and out of the cabinet41 ',thecabinet includes double doors 107 and 108. In addition, the deflector assembly 52' comprises four deflector shield portions 67', 67", 67"' and 67"", the central shield portions 67' and 67" being joined between theirtop ends by a flat flange portion (not shown) covering the central unit 103.

In the arrangement shown in Figure 10, again there are double doors 107' and 108', butthistimesince there arefour racks 111 to 114arranged as shown, there are six steamer units 115to 120 comprising tanks 11, with associated "dry" heating elements (not shown) disposed beneath each unit and associated deflector shield portions 67', 67", 67"' and 67"". Again, the units 115to 120arefedfrom a mastercylinder53" via interconnecting pipes 58", 59", 104,121,122 and 123 to permit of control by a single float switch 62 (not shown).

Generally speaking, in putting the invention into effect it is preferred to use a plurality of steamer units and/orassociated "dry" heating elements ratherthan a heater or heating element of higher power within any particular energy level context. Thus, as shown it is preferred to utilise say from about one to abouttwo steamer units per"rack" ratherthan upgrade the heaterofthe unit to accommodate a higher rackto steamer unit ratio. Furthermore, in all ofthe prover arrangements shown in Figures 5,9 and 10 the remaining cabinet controls are essentially as de scribed with reference to Figure 2.

As will be appreciated from the above description, steamer units in accordance with the invention have the advantagethatthey include the minimum of working parts in contact with water. In particular, there are no spray devices as may be used in the second type of prover steamer unit mentioned in the introduction given above. Furthermore,the unitofthe invention: 1. Because of its "slimline" arrangement occu pies a minimum amount of prover space, 2. Because of its abilityto be disposed within the prover (withoutsacrificing valuable space) it can contribute by virtue ofthe heat radiated fromwalls19tothemaintenanceoftheoverall temperatureofthe prover and thereby can lower the overall power consumption of the prover, 3.Because the heating elements are not in direct contactwith watertheycan enjoy a much longer life, 4. Becaus"theoreach unit can be set at the base ofthe provercabinetthe mass of steam produced can be much less than with known "rack" provers, and 5. Because the unit or each unit can be disposed within the prover it can warm the walls ofthe prover cabinet and minimise condensation.

The steamer unit ofthe invention is especially suitable for use with a proverwhich isto be employed as part of a rack system, while at the sametime giving a numberof advantages overknown units disposed outside rack provers. In particular, the steamer unit of the invention makes it possible forthe rack system to compete on more equal economic terms with those systems using a mobile proverthan was previously the case.

it is to be understood, however,thatthesteamer unitoftheinvention,whileitprovidesparticularand highly desirable advantages when used in association with a prover which itself is part of a rack system, nevertheless can be used to provide a steamer unit or units within a "mobile" prover including its own array of racked trays as an alternative to the open tank arrangement described in the introduction given above.

Also, it is to be understood thatthe invention is not limited to the specific details given above in the description with reference to the accompanying drawings. For example, a variety of arrangements, constructions and combination of steamer units may be employed within the overall am bit of the invention, as well as a variety of prover cabinet and rack arrangements.

In particular, otherwater level control arrangements may be employed. For example, each tank 11 may additionally or alternatively include one or more water sensor probes connected to a remote control box which itself controls the waterfeed to the tank.

Also, such sensors may be infra-red sensors or any other suitable known arrangement.

Claims (23)

1. A steamer unitfor use in a dough prover,which unit comprises a watertank having a water inlet and at least one steam outlet, the tank being shaped as a panel having radiator side walls of large surface area, and bottom and end walls of small surface area, and the tank including a heater disposed to heat its interior space, with the steam outlet or outlets being disposed in communication with an upper portion of the interior of the tank.

2. A steamer unit according to claim 1, wherein the unit includes a water level sensor and a water inlet control valve, the sensor and valve being arranged to permitthe sensorto operate the valve to top up the tank with waterwhen in use.

3. A steamer unit according to claim 2, wherein the tank includes a water outlet disposed in communication with a lower portion ofthe interior ofthe tank and connected to a pressure-sensitive switch whereby as the water level in the tank drops in use the switch at set pressures can operate the water inlet control valveto open and close it.

4. A steamer unit according to claim 1, wherein the water inlet ofthetank is connected to a master container adapted to supply water on demand.

5. A steamer unit according to claim 4, wherein the master container is arranged to feed water under gravity to thetankthrough its water inlet, the level of water in the container and tank being controlled bya switch arranged to operate a water inlet control valve in a waterfeed line from a remote watersource to the master container.

6. A steamer unit according to any one of claims 2 to S,wherein the water inlet control valve is a solenoid valve.

7. Asteamerunitaccording to any one ofthe preceding claims, wherein the heater comprises a heating element disposed in at least one sealed tube passing through the tank in a lower portion thereof.

8. A steamer unit according to claim 7, wherein the heater comprises a pair of said tubes housing a hairpin-shaped heating element.

9. A steamer unit according to any one of the preceding claims, wherein the tank has a closed top and the steam outlet or outlets are disposed in an upper portion of one radiator side wall ofthe tank.

10. Asteamerunit according to any one of claims 1 to 8, wherein the tank has a closed top and one or more steam outlets communicate with the interior of the tank through an upper portion of at least one end wall.

11. A steamer unit according to claim 10, wherein one or moresteam outlets are formed in a tube connected to thetankthrough an end wall ofthetank.

12. A steamer unit according to claim 10, wherein one or more steam outlets are formed in each of two tubes connected to the tank one through each ofthe opposed end walls ofthetank.

13. A steamer unit according to any one of claims 1 to 8, wherein the tank has an open top to provide a steam outlet.

14. A steamer unit according to claim 13, wherein the tank is associated with an arrangement adapted to deflect steam exiting from the top of the tank so that it is directed down at least one radiator side wall.

15. A steamer unit according to claim 14, wherein the deflector arrangement is a deflector shield shaped to fit around the top ofthetank and to depend down at least part of said at least one side wall.

16. An assembly of steamer units comprising a plurality of units according to any one of claims 1 to 11 or 13 to 15 in which their respective tanks are connected, in their lower portions, to provide a sealed path for water between them.

17. An assembly according to claim 16, comprising two orfour unitsaccordingto any one of claims 1 toll or13to 15.

18. An assembly of streamer units comprising at leasttwo units according to any one of claims 1,4to 11 1 or 13 to 15 each associated with a single master container arranged to feed water under gravity either directly or indirectly to said units.

19. Heating apparatus, which apparatus comprises a steamer unit according to any one of claims 1 to 15 or an assembly according to any one of claims 16 to 18,togetherwith a second heating element associated with the or each steamer unit tank but mounted outside ofthetank and/or one or more power control means.

20. Apparatus according to claim 19,wherein the or each heating element is mounted beneath atank.

21. Apparatus according to claim 19 or claim 20, which includes a first control means to control the power fed to the heater or heaters within the steamer u nit tank o r tanks, a second control means to control the powerfed to the heating element or elements outsidethe steamer unittank ortanks and a thermostat overall to control the power fed to the heater(s) and heating element(s) on atemperature basis.

22. A dough prover including a steamer unit according to any one of claim 1 to 15, an assembly of units according to any one of claims 16to 18, or heating apparatus according to any one of claims 19 to 21.

23. Asteamerunitoranassemblyofsteamer units, heating apparatus and/or a dough prover substantially as hereinbefore described with reference to or as illustrated in the accompany drawings.