Roaster arrangement for bulk plant material and method for operating a roaster arrangement

Abstract

A roasting arrangement for bulk plant material (16) comprising a housing arrangement (4) comprising at least one roasting device (6) with an interior space (10) in which the bulk material (16) is to be roasted, a heating arrangement (8) which enables heat transfer to the bulk material (16) in the interior space (10) by means of a heating fluid, a solids separator for cleaning exhaust gases from the roasting device (6), and a control arrangement (20) for controlling a roasting process, characterized in that the heating arrangement (8) comprises, for realizing different heating modes, an electric heating element (22) which is fluidically connected to a first heating fluid line (26) and a gas combustion device (24) which is fluidically connected to a second heating fluid line (28), wherein the first and the second heating fluid lines (28) are fluidically connected to a third heating fluid line (32) via a heating fluid connecting element (30).which is fluidically connected to the roasting device (6).

Description

The invention relates to a roaster arrangement for vegetable bulk material having a housing arrangement which has at least one roaster having an interior in which the bulk material is to be roasted, a heating arrangement which makes possible a heat transport by means of a heating fluid to the bulk material in the interior by means of a heating fluid, a solids separation device for cleaning exhaust gases from the roaster, and a control arrangement for controlling a roasting process. The invention further relates to a method for operating such a roaster arrangement.Roaster arrangements for roasting bulk vegetable material are sufficiently known from the prior art. In this context, reference is made, merely by way of example, to DE 10 2004 038 730 B3, which discloses a roaster arrangement used in the industrial sector. In a conventional manner, such roaster arrangements comprise a gas burner as a heating arrangement for heating a heating fluid. A roasting arrangement for roasting coffee beans with a heating arrangement is also known from DE 10 2015 121 674 A1. In particular, the energy consumption in the roasting process can be optimized still further.It is therefore an object of the invention to avoid the above-mentioned disadvantage in a simple and cost-effective manner.This object is achieved by a roaster arrangement according to the invention in that the heating arrangement has an electric heating element, which is fluidically connected to a first heating fluid line, and a gas burning device, which is fluidically connected to a second heating fluid line, for realizing different heating modes, wherein the first and the second heating fluid line are fluidically connected to a third heating fluid line, which is fluidically connected to the roaster, via a heating fluid connecting element. This makes it possible in a simple manner to operate the roaster arrangement according to the invention with gas and / or current. Especially when renewable energies are used, such as solar energy and / or wind energy, it is necessary to assume operating times in which electricity is not available from these renewable energies. In this case, the heating arrangement can be operated with gas in a simple manner. The bulk material in the interior can be roasted convectively and / or conductively and / or by radiant heat. In this context, heating arrangement is understood to mean all adjustable means which ensure heating of the bulk material, such as, for example, the electric heating element, the gas burning device, such as fans, flaps, etc. Interior parts are understood to mean, for example, the interior walls and also the stirrer, or else a drum or shell. There are a large number of different roaster arrangements, the interior of which can be constructed in very different ways.In a particularly advantageous embodiment, the heating arrangement allows roasting the bulk material in the interior by means of the heating fluid convectively and / or conductively and / or by radiation heat.In a further advantageous embodiment, a vacuum blower arranged behind the roasting device, as seen in the flow direction of the heating fluid, can be provided for suctioning the heating fluid from the roasting device. Due to the reduced pressure present in the roasting device, a uniform supply of heating fluid can be ensured, regardless of the heating mode.Further, a heating mode setting door may be advantageously provided in the heating fluid communication member, whereby it is possible to quickly change the heating mode. A mixed operation is also possible here. In order to minimize a possible flow resistance for the heating fluid, the connecting element can be designed in a particularly advantageous manner as a Y-heating fluid connecting element.In a particularly advantageous manner, an air supply blower is provided on a side of the electric heating element facing away from the first heating fluid line in front of the electric heating element.In a particularly advantageous manner, the roasting device has at least one sensor element for monitoring the roasting process. In this way, in particular, an active control of the roasting process is possible either by the user himself, when he receives a message from the control arrangement, or automatically by the control arrangement.Advantageously, the heating arrangement is fluidly connected to a first exhaust gas recirculation line for recirculating purified exhaust gas to the heating arrangement, thereby reducing emissions and heating the heating fluid and thereby saving energy. In this case, both the electric heating element and the gas combustion device can be fluidically connected to the first exhaust gas recirculation line via a second and a third exhaust gas recirculation line via a Y exhaust gas connecting element. In order to ensure optimum supply of the recirculated exhaust gas, an exhaust gas recirculation flap can be provided in the Y exhaust gas connecting element.For particularly accurate heating fluid adaptation, which is desired in some roast recipes, a heating fluid bypass line to the exhaust gas line may be provided with the solids separation device. Here, a heating fluid adjustment cap may be provided in the heating fluid bypass line.In order to preheat the gas burning device, a connecting line may be provided between the electric heating element and the gas burning device. In this case, it is advantageous if a nonreturn valve is provided in the connecting line in order to prevent heating gas from reaching the electric heating element.The object is also achieved by a method for operating such a roaster arrangement, wherein before a change of the heating mode the third heating fluid line and the roaster are flushed with supply air. In this case, the supply air for the flushing process can be provided by the supply air fan of the electric heating element.The invention will be explained in more detail with reference to a drawing, the single figure showing a schematic representation of a roaster arrangement according to the invention.The single FIGURE shows a schematic illustration of a roaster arrangement 2 according to the invention, which is sufficiently known per se from the prior art. Such a roaster arrangement 2 has a housing arrangement 4 which has at least one roaster 6, a heating arrangement 8 for heating an interior 10 of the roaster 6, a solids separation device 12 for cleaning exhaust gases from the interior 10 of the roaster 6, and in the present exemplary embodiment a cooling arrangement 14 for cooling a vegetable bulk material to be roasted, in this case coffee beans 16. The unpopped coffee beans 16 are hereby supplied to the interior 10 of the roasting device 6 via a hopper inlet 18. In addition, a control arrangement 20 is provided which controls or regulates a cooling process in a roasting process.According to the invention, the heating arrangement 8 first has an electric heating element 22 and a gas burning device 24, which provide a heating fluid by heating an incoming air, which heating fluid is a heating gas in the case of the electric heating element 22 as heating air and a heating gas in the case of the gas burning device 24. In the present exemplary embodiment, the electric heating element 22 is followed by a first heating fluid line 26 and the gas burning device 24 is followed by a second heating fluid line 28, which are fluidically connected to a third heating fluid line 32 via a Y heating fluid connecting element 30, wherein the third heating fluid line 32 guides the heating fluid to the roasting device 6.On a side of the electric heating element 22 facing away from the first heating fluid line 26, a supply air blower 34 is provided in front of the electric heating element 22, so that a uniform heating air flow can be ensured. In addition, reliable cooling of the electric heating element 22 is ensured in all operating situations. The gas burning device 24 also has a fan 36 in a known manner. In addition, a connecting line 40 with a nonreturn valve 42 is provided from the electric heating element 22 to the supply air inlet 38 of the fan 36 in order to preheat the supply air of the gas burning device 24. In order to be able to set different heating modes, a heating mode setting flap 44 is also provided in the Y-heating fluid connection member 30. The third heating fluid line 32 also has a heating fluid flap 46, which together with an exhaust gas flap 48 and a vacuum fan 50 as part of the heating arrangement 8 together with the aforementioned means 22- 44, influence a heating fluid mass flow, an exhaust gas mass flow and a temperature of the roasting process. In the present exemplary embodiment, heat transport to the coffee beans 16 thus takes place both convectively and conductively and by radiant heat.In the present exemplary embodiment, the cooling arrangement 14 consists of a cooling device 52 with a flat bed cooler 54, onto which the coffee beans 16 are poured via an outlet opening 56 of the roasting device 6. The flat bed cooler 54 includes together with a hood arrangement 58 a cooling chamber 60 into which cooling air is blown by a cold air device 62. The cooling device 52 is followed in a known manner by a bulk material outlet arrangement 64 and a cooling air discharge device 66.In the present exemplary embodiment, the temperature of the coffee beans 16 in the interior 10 of the roasting device 6 is monitored by a sensor element 67, which is here advantageously configured in a contactless manner.As already described above, a solid matter separation device 12 is provided, which can clean and discharge the exhaust gas to the environment in a known manner. However, a first exhaust gas recirculation line 68, which is known to be fluidically connected to a second and a third exhaust gas recirculation line 78, 80 via a Y exhaust gas connecting element 74 with an exhaust gas recirculation flap 76, is also provided in order to recirculate exhaust gas to the electric heating element 22 and / or to the gas combustion device 24 for preheating the respective supply air.In order to enable an additional adjustment possibility for a quick adaptation within the scope of a roast recipe, a heating fluid bypass line 82 with a heating fluid adjustment flap 84 is additionally provided to the solids separation device 12.In order to be able to control the roaster arrangement 2 as flexibly as possible, the control device 20 is provided in the present exemplary embodiment with a plurality of components, such as the electric heating element 22, the gas burning device 24, the roasting device 6, the sensor element 67 and the various flaps, for example. 70, and fans, for example. 72, are connectedIt has proven to be particularly effective that before a change of the heating mode, the third heating fluid line 32 and the roasting device 6 are flushed with supply air. The supply air for the flushing process can be provided by the supply air blower 34 of the electric heating element 22.

Claims

Roaster arrangement for vegetable bulk material (16), having a housing arrangement (4) which has at least one roasting device (6) having an interior space (10) in which the bulk material (16) is to be roasted, a heating arrangement (8) which makes possible a heat transport to the bulk material (16) in the interior space (10) by means of a heating fluid, a solid matter separation device for cleaning exhaust gases from the roasting device (6), and a control arrangement (20) for controlling a roasting process, characterized in that the heating arrangement (8) has an electric heating element (22), which is fluidically connected to a first heating fluid line (26), and a gas burning device (24), which is fluidically connected to a second heating fluid line (28), wherein the first and the second heating fluid line (28) are fluidically connected via a heating fluid connecting element (30) to a third heating fluid line (32), which is fluidically connected to the roasting device (6).Roaster arrangement according to claim 1, characterised in that the bulk material (16) in the interior (10) is to be roasted convectively and / or conductively and / or by radiation heat by means of the heating arrangement (8).Roaster arrangement according to claim 1 or 2, characterised in that a vacuum blower (50), which is arranged behind the roasting device (6) as seen in the flow direction of the heating fluid, is provided for suctioning the heating fluid from the roasting device (6).Roaster arrangement according to one of the preceding claims, characterized in that a heating mode setting flap (44) is provided in the heating fluid connection element (30).Roaster arrangement according to claim 4, characterised in that the heating fluid connection element (30) is designed as a Y heating fluid connection element.Roaster arrangement according to one of the preceding claims, characterized in that a supply air fan (34) is provided in front of the electric heating element on a side of the electric heating element (22) facing away from the first heating fluid line (26).Roaster arrangement according to one of the preceding claims, characterized in that the roasting device (6) has at least one sensor element (67) for monitoring the roasting process.Roaster arrangement according to one of the preceding claims, characterized in that the heating arrangement (8) is fluidically connected to a first exhaust gas recirculation line (68).Roaster arrangement according to claim 8, characterised in that both the electric heating element (22) and the gas burning device (24) are each fluidically connected to the first exhaust gas recirculation line (68) via a second and a third exhaust gas recirculation line (78, 80) via a Y exhaust gas connecting element (74).Roaster arrangement according to claim 9, characterised in that an exhaust gas recirculation flap (76) is provided in the Y exhaust gas connecting element (74).Roaster arrangement according to one of the preceding claims, characterized in that a heating fluid bypass line (82) is provided to an exhaust gas line with the solids separation device (12).Roaster arrangement according to claim 11, characterised in that a heating fluid adjustment cap (84) is provided in the heating fluid bypass line (82).Roaster arrangement according to one of the preceding claims, characterized in that a connecting line (40) is provided between the electric heating element (22) and the gas burning device (24).Roaster arrangement according to claim 13, characterised in that a non-return valve (42) is provided in the connecting line (40).Method for operating a roaster arrangement according to one of the preceding claims, characterized in that, before a change of the heating mode, the third heating fluid line (32) and the roaster (6) are flushed with supply air.Method for operating a roaster arrangement according to claim 15, characterised in that the supply air for the flushing process is provided by the supply air fan (34) of the electric heating element (22).

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