Hay steamer

Abstract

Hay steamer (1) for steam treatment of hay comprising a lockable container (10) with a receiving chamber (11) for receiving hay, a steam distribution device (20) in the receiving chamber (11) of the container (10) and a steam generator (30) arranged outside the container (10) and connected to the steam distribution device (20) for generating steam, wherein a temperature sensor (40) is arranged in the receiving chamber (11) of the container (10), which, when filled with hay, is arranged in the hay at a distance of at least 5 cm above the floor (15) of the receiving chamber (11), wherein the distance of the temperature sensor from the floor (15) is a maximum of one third of the height of the receiving chamber (11), and a control device (50) connected to the temperature sensor (40) and the steam generator (30) is provided, wherein the control device (50) is configured to control the steam generator (30) in such a manner as tothat after the start of a steaming process, a predetermined target temperature of at least 80 °C is established and maintained at the temperature sensor (40).

Description

[0001] The invention relates to a hay steamer.

[0002] Hay is cut, dried grass, primarily used as animal feed. Hay is typically dusty and contains not only dust particles but also fungal and yeast spores, mites, bacteria, and viruses. These particles can cause coughing in animals, such as horses, which is particularly undesirable in animals with pre-existing conditions, especially respiratory problems.

[0003] To reduce the burden on hay and thus reduce the urge to cough in animals fed hay, it is known to wash the hay or treat it with steam.

[0004] From DE 20 2017 002 077 U1, a device is known in which hay is treated in a container with steam at a temperature of at least 82 °C, thereby binding dust and killing a large number of germs harmful to horses. Steam is fed into a container for holding the hay to be treated through an inlet opening located at the bottom throughout the entire treatment period, so that the required temperature is reliably reached.

[0005] German patent DE 10 2015 014 066 A1 also describes the steaming of hay, but proposes a higher steaming temperature of over 100 °C to 105 °C, with a brief increase to 122 °C towards the end of the steaming process. This is intended to kill even more germs and increase the shelf life of the steam-treated hay. However, the hay humidifier required to achieve and maintain the desired supercritical steam temperatures is more complex and requires, for example, forced circulation.

[0006] Document GB 2 589 819 A concerns a hay steamer in which steam from a steam source can be introduced into a receiving chamber inside a lockable container by means of an arrangement of several lances placed on the ground.

[0007] Document WO 2022 / 200 266 A1 describes a device for steaming animal feed with a closable intake chamber. Steam can be introduced through an opening in the base.

[0008] The present invention is based on the objective of creating a hay steamer that is improved compared to the prior art, for example by reducing the energy requirement compared to hay steamers in the prior art.

[0009] This problem is solved by a hay steamer according to claim 1. Advantageous further developments are the subject of the dependent claims.

[0010] Accordingly, the invention relates to a hay steamer for steam treatment of hay, comprising a lockable container with a receiving chamber for receiving hay, a steam distribution device in the receiving chamber of the container, and a steam generator arranged outside the container and connected to the steam distribution device for generating steam, wherein a temperature sensor is provided in the receiving chamber of the container, which, when filled with hay, is arranged in the hay at a distance of at least 5 cm above the floor of the receiving chamber, wherein the distance of the temperature sensor from the floor is a maximum of one third of the height of the receiving chamber, and a control device connected to the temperature sensor and the steam generator, wherein the control device is configured to control the steam generator in such a way as tothat after the start of a steaming process, a predetermined target temperature of at least 80 °C is reached and maintained at the temperature sensor.

[0011] First, some terms used in connection with the invention will be explained.

[0012] The "container" creates an internal storage space that can be optionally closed, for example, by a lid and / or a door. It is not necessary for the container to be designed as a pressure vessel. However, it is preferable if the container is not pressure-tight, which also makes the optional closure of the container simple and cost-effective.

[0013] "Water vapor" refers to water which—apart from any droplets that may have already condensed—exists in the gaseous state at ambient pressure. The term therefore encompasses both wet steam and superheated steam. Since, in connection with the invention, practically no, and in particular no sustained, pressure increase relative to the surroundings occurs, at least the gaseous component of the water vapor has a temperature of at least approximately 100 °C at typical ambient pressures of approximately 1 bar. It must be ensured that the water vapor has a temperature above the target temperature so that the target temperature can actually be achieved simply by introducing the water vapor into the receiving chamber.

[0014] The invention is based on the understanding that by measuring the temperature inside the receiving chamber, more precise control of the steam generator is possible, thus eliminating the need for continuous operation of the steam generator during the entire steaming process. To ensure sufficient steaming of the hay, it is essential that the temperature be measured within the hay and at least 5 cm from the floor of the receiving chamber. This prevents potentially unrepresentative temperature readings resulting from direct contact of steam escaping from the steam distribution device with the temperature sensor. The steam generator can then be controlled by the control unit to establish and maintain a predetermined temperature of at least 80 °C at the temperature sensor.It has been found that neither continuous operation of the steam generator nor forced circulation in the recording room is necessary for this.

[0015] It is preferred that the temperature sensor be designed as a loose sensor that can be inserted by a user at a suitable height above the ground into hay that has already been at least partially introduced into the receiving area. In particular, if the hay to be treated is already portioned in a feeding net, the temperature sensor can be inserted into the hay of the first feeding net placed in the receiving area before any further feeding nets are added. The temperature sensor can be wireless or connected to a flexible cable.

[0016] Alternatively, the temperature sensor can be designed to extend from the floor of the receiving chamber into it by at least a height corresponding to the desired distance from the floor, for example, in the form of a slender rod, possibly with a pointed end, in which the actual temperature sensor element is positioned at the desired height relative to the floor of the receiving chamber. When the receiving chamber is filled with hay, the hay wraps around the temperature sensor, so that the sensor is then also located within the hay. In this design, the temperature sensor can be a separate component. However, it is also possible for it to form a single unit with the steam distribution device.

[0017] The distance of the temperature sensor from the floor is a maximum of one-third of the height of the receiving chamber. In any case, it is preferred if the distance of the temperature sensor from the floor is at least 10 cm and / or a maximum of 10 cm to 15 cm. A corresponding minimum distance further reduces the risk of the temperature sensor being directly exposed to steam escaping from the steam distribution device. By setting an upper limit on the distance, the temperature gradient that may occur within the vessel due to convection can be taken into account in such a way that the temperature determined by the temperature sensor is at least close to the minimum temperature prevailing in the receiving chamber, thus ensuring that the predetermined target temperature is not undershot in the entire receiving chamber once the temperature sensor has detected that it has been reached.

[0018] It is preferred if the target temperature is between 80 °C and 90 °C. A target temperature within this range has proven sufficient, particularly for hay to be fed immediately after steaming, with a temperature at the upper end of the range being more suitable for coarser hay and a temperature at the lower end for finer hay.

[0019] Preferably, the control device is designed to maintain the target temperature, after it has initially been reached at the temperature sensor, essentially constant for a predetermined period, preferably 15 to 40 minutes, and more preferably 20 to 30 minutes. Maintaining a temperature for a certain period is a well-known principle for hay steaming. However, with the control device, it is now possible to reliably maintain an optimal duration and, in particular, to avoid any detrimental exceeding of the ideal steaming time.

[0020] It is further preferred if the control device is designed for time preselection. A time preselection allows either a desired future start or end time to be set, at which a steaming process should begin or be completed. This makes it possible to preload the hay steamer with hay, but only carry out the actual steaming at the time when the hay is to be fed. The start preselection is self-explanatory. For the end preselection, in addition to the preset steaming duration, an estimated warm-up phase and a preset cooling phase are taken into account so that the control device, based on corresponding stored values ​​and starting from the selected end time, can determine a start time at which the steaming process must be initiated by the control device.

[0021] The steam generator is preferably a boiling evaporator, i.e., a steam generator in which water in a container is brought to a boil by a heating element in order to produce steam. Regardless of the specific method of steam generation, the steam generator preferably has a level sensor and / or a controllable water supply. Boiling evaporators, as well as other possible steam generators, can generally only be switched on and off and do not offer any further control options.Particularly when using a steam generator that can only be activated and deactivated, it is preferred if a delta temperature, preferably of 2 K, is specified to the control device and the control device is designed such that the steam generator is operated until a temperature of target temperature plus delta temperature at the temperature sensor is reached and is only switched on again when the temperature at the temperature sensor has dropped to the target temperature.

[0022] The level sensor serves to check whether there is sufficient water in the steam generator to produce steam. The water supply to the steam generator can be regulated via the level sensor. While it is possible for separate control logic to be provided on the steam generator, it is preferred that the control device be connected to the level sensor and designed to control the adjustable water supply to ensure a predetermined water level in the steam generator. As a safeguard, a time-based monitoring of the adjustable water supply can be provided. If the desired water level in the steam generator is not reached within a predetermined time after activation of the adjustable water supply, the control device will issue an alarm and / or terminate the steaming process. In this case, a malfunction in the adjustable water supply or a leak in the steam generator must be assumed.

[0023] A controllable water supply can consist of a controllable pump or a controllable valve. A controllable pump is particularly useful for controlling the water supply from a water reservoir, such as a water canister. A controllable valve is especially suitable for controlling the water supply via a pressurized water line.

[0024] The lockable container may have a lid or similar device for selective opening and closing. It is preferred that a controllable locking element, e.g., a magnetic closure, is provided, which, when activated, can temporarily prevent the locked container from being opened. The control device is then preferably designed to activate the locking element at least temporarily during hay steaming, possibly including a predetermined cooling period, and / or when the temperature at the temperature sensor exceeds a predetermined limit. This ensures that the container is not accidentally opened during the steaming process or during periods of high temperatures in the receiving chamber.

[0025] The steam distribution device preferably rests loosely on the floor of the receiving chamber. This allows it to be easily removed, for example, for cleaning the receiving chamber. The steam distribution device can consist of a tubular frame, preferably made of stainless steel, with a connection for the steam generator and a multitude of steam outlet openings. The tubular frame can be adapted to the dimensions of the receiving chamber in such a way as to ensure the most uniform possible steam distribution.

[0026] It is preferred that the container be made of polypropylene. This material has proven to be sufficiently temperature-resistant, at least within the preferred range of 80°C to 90°C, and is also food-safe.

[0027] The container may also have a condensate drain, preferably located at the bottom of the receiving chamber. Any condensate that may form, as well as cleaning agents used to clean the receiving chamber, can be optionally drained via this condensate drain.

[0028] The invention will now be described by way of example with reference to advantageous embodiments and the accompanying drawings. These show: Fig. 1: a first embodiment of a hay steamer according to the invention; and Fig. 2: a second embodiment of a hay steamer according to the invention.

[0029] In Fig. Figure 1 shows a first embodiment of a hay steamer 1 according to the invention for steam treatment of hay.

[0030] The hay steamer 1 comprises a container 10 with a receiving chamber 11 for the hay to be steamed. The container 10 can be optionally closed by means of its pivoting lid 12. However, even in the closed position, the lid 12 does not create a pressure-tight seal. A controllable magnetic closure is provided on the lid 12 as a safety element 13, with which the lid 12 can be secured in the closed position if required.

[0031] At the bottom of the receiving chamber 11, the container 10 has a condensate drain 14 which can be opened as needed to allow condensate or, for example, cleaning agents contained in the receiving chamber to drain away. The container 10 and its lid 12 are made of polypropylene, which is sufficiently temperature-resistant and also food-safe.

[0032] A steam distribution device 20 rests loosely on the floor 15 of the receiving chamber 11. The steam distribution device 20 comprises a stainless steel tubular frame 21. A plurality of steam outlet openings 22 are distributed along the tubular frame 21. Furthermore, the tubular frame 21 has a connection 23 for a steam generator 30 located outside the receiving chamber 11. A flexible hose section 24 is provided between the connection 23 and the steam generator 30.

[0033] A cooking evaporator 31 is provided as a steam generator 30. Inside the steam generator, water contained in a cooking vessel is brought to a boil by a heating element (not shown) to generate hot steam. In addition to a drainage valve 32, which can be opened manually as needed, for example, for cleaning and / or descaling purposes, the steam generator 31 has a controllable water supply 33 in the form of a suction pump. This pump draws water from a water container connected to the water inlet 34 into the cooking vessel inside the steam generator. Furthermore, the steam generator 30 has a level sensor 35 designed as a level electrode. This sensor determines whether the water level in the cooking vessel is greater than or equal to a target level specified by the level sensor 35.

[0034] The cooking evaporator 31 (in particular its heating element), the controllable water supply 33, and the level sensor 35 are connected to a control device 50. The control device 50 is also connected – via a control line not shown – to the safety device 13 of the lid 12.

[0035] A temperature sensor 40 is also connected to the control device 50. The temperature sensor 40 is designed as a loose, wired temperature sensor 40 and is located in the receiving chamber 11. The temperature sensor 40 can be inserted by a user at a distance of approximately 10 cm to 15 cm from the floor 15 in a receiving chamber 11 that is already at least partially filled with hay, at which point the temperature sensor 40 is considered to be located in the hay.

[0036] The control device 50, which can be operated via an operating panel 51, is designed to control various processes. Alternatively or additionally to an operating panel 51 arranged directly on the hay steamer 1, a virtual operating panel 51, which can be displayed, for example, on a mobile device, can also be provided.

[0037] In particular, the control device 50 serves to carry out a steaming process for hay brought into the receiving chamber 11, for which the container 10 is closed.

[0038] At the start of the steaming process, the cooking evaporator 31 is activated, generating steam which is then introduced through the steam distributor 20 into the receiving chamber 11 and the hay contained therein. The cooking evaporator 31 operates until the temperature at the temperature sensor 30, monitored by the control device 50, reaches a temperature 2 K above a target temperature preset via the control panel 51, which is selected from the temperature range of 80 °C to 90 °C. Once the target temperature plus 2 K is reached, the cooking evaporator 31 is deactivated until the temperature at the temperature sensor 40 falls below the target temperature. As soon as the target temperature is undershot, the cooking evaporator 31 is reactivated until the target temperature plus 2 K is reached again. As a result, the target temperature at the temperature sensor 40 is maintained (with a deviation of up to 2 K).

[0039] Once the target temperature is reached at temperature sensor 40 after the start of a steaming process, a timer for the steaming time is started in the control device 50. The duration of this timer is preset via the control panel 51. The control panel 51 generally allows the steaming time to be set from 15 to 40 minutes, with steaming times of 20 to 30 minutes being particularly preferred. While the timer is running, the target temperature at temperature sensor 40 is maintained as described above. Once the preset steaming time has elapsed, the cooking evaporator 31 is switched off. A cooling phase then begins, at the end of which the steamed hay can be removed from the intake chamber 11 and fed to animals.

[0040] The control device 50 activates the safety element 13 at the start of the steaming process, preventing the lid 12 of the container 10 from being accidentally opened. The safety element 13 is only deactivated when the predetermined steaming time has elapsed and the temperature at the temperature sensor 40 has dropped below a predetermined value.

[0041] Throughout the entire steaming process, the control device 50 monitors the water level in the heating vessel of the cooking evaporator 31 using the level sensor 35. If the level sensor 35 indicates a water level below the target level, the control device 50 activates the controllable water supply 33 until the target level is reached again. The control device 50 also monitors the operating time of the controllable water supply 33. If the target level is not reached within a predetermined period after activation of the controllable water supply 33, the steaming process is terminated, as safe operation, particularly of the cooking evaporator 31, can no longer be guaranteed. In the illustrated embodiment, possible causes include an empty water vessel with a closed water connection 34 or a leak in the cooking evaporator 31.

[0042] The control device 50 is further equipped for time preselection. In addition to a target temperature and a steaming duration, a desired end time for the steaming process can also be set via the operating panel 51. The control device 50 begins the steaming process at a time calculated based on the desired end time, the set steaming duration, and predefined time periods determined from experience, from the start of the steaming process until the target temperature is first reached, as well as for the cooling process.

[0043] In Fig. Figure 2 shows a second embodiment of a hay steamer 1 according to the invention. The hay steamer 1 essentially corresponds to the one described in Figure 2. Fig. 1, which is why reference is made to the above statements and only the differences are pointed out below.

[0044] In this embodiment, the temperature sensor 40 extends 15 cm into the receiving chamber 11 from its base 15. The temperature sensor 40 has a pointed tip so that when the receiving chamber 11 is filled with hay, the temperature sensor 40 penetrates the hay and is surrounded by it, as desired.

[0045] Furthermore, instead of a suction pump, a solenoid valve controllable by the control device 50 is provided as the controllable water supply 33. The hay steamer 1 is thus designed for connection to a pressurized water line.

[0046] The recording room 11 of the two exemplary embodiments from Fig. 1 and Fig.The hay steamer 2 has a volume of approximately 700 liters, which means it is designed for a maximum of approximately 35 kg of hay. In tests with a full load, approximately 3 liters of water were required for evaporation during a complete steaming process with a steaming time of 20 minutes, of which approximately 1 liter condensed. The entire steaming process, including heating and cooling, took approximately 40 minutes. Although these figures are from tests with a prototype, they nevertheless demonstrate the fundamental order of magnitude for the operation of a hay steamer 1 according to the invention.

Claims

[1] Hay steamer (1) for steam treatment of hay comprising a lockable container (10) with a receiving chamber (11) for receiving hay, a steam distribution device (20) in the receiving chamber (11) of the container (10) and a steam generator (30) arranged outside the container (10) and connected to the steam distribution device (20) for generating steam, wherein a temperature sensor (40) is arranged in the receiving chamber (11) of the container (10) at a distance of at least 5 cm above the floor (15) of the receiving chamber (11) in the hay when filled with hay, wherein the distance of the temperature sensor from the floor (15) is a maximum of one third of the height of the receiving chamber (11), and a control device (50) connected to the temperature sensor (40) and the steam generator (30) is provided, wherein the control device (50) is configured to control the steam generator (30) in such a way as to steer,that after the start of a steaming process, a predetermined target temperature of at least 80 °C is established and maintained at the temperature sensor (40). [2] Hay steamer according to claim 1, characterized by , that the temperature sensor (40) is designed as a loose temperature sensor which can be inserted by a user at a suitable height at least 5 cm above the floor (15) and at most one third of the height of the receiving space (11) into hay already placed in the receiving space (11). [3] Hay steamer according to claim 1, characterized by , that the temperature sensor (40) is designed to extend into the recording space (11) from the floor (15) by a height at least corresponding to the desired distance of at least 5 cm from the floor (15) and at most one third of the height of the recording space (11). [4] Hay steamer according to any one of the preceding claims, characterized by that the target temperature is 80 °C to 90 °C. [5] Hay steamer according to any one of the preceding claims, characterized by , that the distance of the temperature sensor from the floor (15) is at least 10 cm and / or at most 10 cm to 15 cm. [6] Hay steamer according to any one of the preceding claims, characterized by , that the control device (50) is designed to maintain the target temperature constant for a predetermined period of time, preferably 15 to 40 minutes, and more preferably 20 to 30 minutes, after it has initially been reached at the temperature sensor (40). [7] Hay steamer according to any one of the preceding claims, characterized by , that the control device (50) is designed for a time preselection. [8] Hay steamer according to any one of the preceding claims, characterized by , that the steam generator (30) is a cooking evaporator (31) and / or has a level sensor (35) and / or a controllable water supply (33). [9] Hay steamer according to claim 8, characterized by, that the steam generator (30) has a level sensor (35) and the control device (50) is connected to the level sensor (35) and is designed to control the water supply (33) of the steam generator (30) in order to ensure a predetermined water level in the steam generator (30), preferably with regard to time monitoring of the controllable water supply (33), for which the control device (40) is designed to issue an alarm and / or to terminate an ongoing steaming process if the predetermined level in the steam generator (30) is not reached within a predetermined time after activation of the controllable water supply (33). [10] Hay steamer according to claim 8 or 9, characterized by , that the steam generator (30) has a controllable water supply (33) and the controllable water supply (33) includes a controllable pump or a controllable valve. [11] Hay steamer according to any one of the preceding claims, characterized by , that the lockable container (10) has a locking element (13) which, when activated, can temporarily prevent the opening of the locked container (10), wherein the locking element (13) is preferably controllable by the control device (50). [12] Hay steamer according to any one of the preceding claims, characterized by that the steam distribution device (20) rests loosely on the floor (15) of the receiving space (11) and / or has a tubular frame (21), preferably made of stainless steel, with a connection for the steam generator (23) and a plurality of steam outlet openings (22). [13] Hay steamer according to any one of the preceding claims, characterized by that the lockable container (10) is made of polypropylene and / or has a condensate drain (14).

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