Patent Description:
Hay, and other types of fodder such as straw, silage and haylage, are commonly fed to horses, as well as other livestock, and may be used for growing plants, fruit and vegetables such as mushrooms. However, such fodder may contain many different types of bacteria, mould spores and dust particles that can affect a horse's breathing and cause coughing. The particles are respiratory irritants, and can lead to respiratory diseases such as chronic obstructive pulmonary disease (COPD).

It is well known to soak hay with water to mitigate respiratory issues in horses and other livestock. Soaking the hay causes the particles to stick to the hay, so they are consumed, rather than inhaled. However, soaking reduces the sugar content in the hay and can also result in loss of nutrients. Soaked hay is also significantly heavier due to the increased water content, making it harder to carry. If left for too long, the soaked hay can spoil as bacteria builds up, since soaking does not kill the particles.

Some of these disadvantages may be overcome by using a hay steamer to treat hay bales with steam in order to remove and kill the bacteria, mould spores, fungi and dust particles. Steaming the hay or other silage reduces the risk of causing and/or exasperating allergies and respiratory issues. The advantages of using a steamer over soaking hay include increased removal of the particles, less nutrient loss, more palatable hay, and increased water intake by a horse, improving their hydration. In addition, significantly less water is needed for steaming compared to soaking.

An example of a hay steamer is to be found in patent publication <CIT>. The body of the hay steamer comprises four side walls that rise from a base to form a chamber into which hay bales may be loaded. The top of the steamer comprises a hinged lid that may be opened to allow loading and unloading of hay bales, and closed to form a closed chamber when the hay bales are being steamed. A separate boiler unit heats water to produce steam. The boiler unit is connected to the body of the hay steamer via a hose which, in turn, connects to further hoses and then to lances that extend into the chamber and penetrate any bale loaded in the chamber. In this way, steam generated by the boiler unit travels to and through the body of the hay steamer, and then passes through at least one steam distribution manifold and into the lances from where the steam is injected into the hay bale through apertures in the lances. The hot steam rises through the hay bale, treating the hay bale as it does so. Typically, the bale is exposed to a continuous supply of steam for approximately <NUM> minutes, heating the bale to between <NUM> and <NUM>. When steaming is complete, the hay steamer must be switched off manually to avoid the boiler running dry and potentially causing damage to the steamer.

There is therefore a need to provide an improved hay steamer.

In a first aspect, there is provided an apparatus for steaming animal fodder, comprising a body defining a chamber in which animal fodder may be placed. The body comprises an upper part and a lower part configured to be placed together to form the chamber. The lower part includes a floor on which the animal fodder is supported. An aperture is provided in the floor of the lower part. The apparatus further comprises a conduit configured to carry steam to the aperture. Steam passing along the conduit and through the aperture enters the chamber formed by the body.

The apparatus also comprises a controller arranged to control passage of steam to and through the aperture in at least one combined cycle. The combined cycle comprises a low-pressure phase and a high pressure phase. In the low-pressure phase, the controller allows steam to pass from the aperture into the chamber at a relatively low pressure. In the high-pressure phase, the controller allows steam to pass from the aperture into the chamber at a relatively high pressure. The terms relatively low pressure and relatively high pressure define the pressures relative to each other. Hence, the relatively low pressure is a lower pressure than the relatively high pressure. In each combined cycle of the least one combined cycle, the low-pressure phase is followed by the high-pressure phase.

It has been found that providing at least one combined cycle of a low-pressure phase and a high pressure-phase when steaming the animal fodder is beneficial. The low-pressure phase may be used to gently introduce steam into the chamber such that a blanket of steam builds up at the bottom of the animal fodder that rests over the aperture. Then, the high-pressure phase may be used provide jets of steam that drive the blanket of steam upwards through the animal fodder. This provides more even steaming throughout the bale, and also allows the temperature of the animal fodder to rise more quickly, resulting a quicker steaming cycle. Without the high-pressure phase, the steam moves through the animal fodder by convection which is slow. The high-pressure phase forces steam up and outwardly through the animal fodder, ensuring the extremities of the animal fodder are treated with steam while also accelerating the temperature rise from the bottom to the top of the animal fodder. Hence, the combination of low-pressure and high-pressure phases has been found to provide improved steaming of the animal fodder.

Optionally, the apparatus may comprise a valve arranged to open and close. When open, the valve allows steam to pass through the aperture. When closed, the valve prevents steam from passing through the aperture. The valve may be located at the aperture or before the aperture. The controller is arranged to open and close the valve. In particular, the controller is arranged to open the valve to allow steam to pass from the aperture in the low-pressure phase of each combined cycle of the least one combined cycle, and also to open the valve to allow steam to pass from the aperture in the high-pressure phase of each combined cycle of the least one combined cycle. Hence, the controller may be used to control when steaming is performed during the low-pressure and high-pressure phases. The controller may be a suitably programmed computer or a suitably arranged electronic circuit.

The controller may also control how the relatively-low and relatively high pressures are achieved. For example, the apparatus may comprise two, three or more apertures provided in the floor, and the controller may control the number of apertures supplied with steam. The controller may provide steam to all apertures in the low-pressure phase, and all the steam to only one aperture in the high-pressure phase.

In a contemplated embodiment, the conduit is a first conduit, the aperture is a first aperture and the valve is a first valve associated with the first aperture. The apparatus may further comprise a second aperture provided in the floor of the lower part, a second conduit configured to carry steam to second aperture thereby allowing steam to pass into the chamber, and a second valve associated with the second aperture. The second valve may be arranged to open and close thereby allowing and preventing steam to pass from the second aperture. In each combined cycle of the least one combined cycle, the controller may be arranged to open the first valve and the second valve to allow steam to pass through the first aperture and the second aperture in the low-pressure phase and in the high-pressure phase. In the low-pressure phase, the controller may be arranged to open the first valve and the second valve simultaneously to allow steam to pass from the first and second apertures simultaneously. In the high-pressure phase, the controller may be arranged to open the first valve and the second valve sequentially to allow steam to pass from the first aperture and the second aperture sequentially.

The controller may use a steam pressure signal to control when steam is allowed to pass form the first and second apertures in the high-pressure mode. Optionally, the controller may be arranged to open the first valve to allow steam to pass through the first aperture when the steam pressure signal indicates that the steam pressure is above an upper pressure threshold and later to close the first valve when the steam pressure signal indicates that the steam pressure has dropped below a lower pressure threshold. The controller may be arranged then to open the second valve to allow steam to pass through the second aperture when the steam pressure signal indicates that the steam pressure is above the upper pressure threshold and later to close the second valve when the steam pressure signal indicates that the steam pressure has dropped below a lower pressure threshold.

In this way, the controller is arranged to allow steam to pass from the first and second apertures sequentially. This ensures that all parts of the steam blanket created during the low-pressure phase are driven upwards during the high-pressure phase.

The apparatus may further comprise a boiler arranged to boil water and generate the steam. In this case, the first conduit and the second conduit may connect the boiler to the first and second aperture respectively, thereby allowing the steam to pass to and through the first and second apertures. A pressure sensor may be positioned in the boiler, for example in the steam chamber of the boiler, and the pressure sensor may be arranged to measure the steam pressure in the boiler and to provide the pressure signal to the controller that provides the measure of the steam pressure. Optionally, the first and second valves are located at or close to the boiler. For example, the first and second valve may be located at first and second outlets from the boiler that connect to the first and second conduits. Alternatively, the boiler may have a single outlet that feeds a manifold that connects to the first and second conduits. In this example, the first and second valves may be provided as part of the manifold or as part of the first and second conduits next to or close to the manifold.

Optionally, the controller is arranged to receive a temperature signal that provides a measure of the temperature in the chamber, and to control passage of the steam from the first and second apertures in the at least one combined cycle according to the temperature indicated by the temperature signal. The controller is arranged to do this such that in a first combined cycle of the at least one combined cycle, the controller controls passage of the steam from the first and second apertures according to the low-pressure phase while the temperature indicated by the temperature signal is below a first temperature threshold, and the controller controls passage of the steam to and through the first and second apertures according to the high-pressure phase when the temperature indicated by the temperature signal rises above the first temperature threshold.

Accordingly, the controller uses a temperature to control when to switch from the low-pressure phase to the high-pressure phase if the first combined cycle. The controller will wait for the temperature to rise to the first temperature threshold before commencing the first high-pressure phase. This sees the low-pressure phase create a blanket of steam that gradually raises the temperature in the chamber until it reaches the first temperature threshold, at which point the high-pressure phase begins to drive the blanket of steam upwardly through the animal fodder.

The apparatus may further comprise a temperature sensor positioned in the upper half of the chamber and wherein the temperature sensor is arranged to measure the temperature in the chamber and to provide the temperature signal to the controller that provides the measure of the temperature in the chamber. The temperature sensor may be positioned at the top of the chamber, for example in an underside of the top of the body, or at or near the top of a wall of the body. In this way, the temperature sensor will measure the temperature at the top of the chamber, and provides a measure of how much heat has spread from the hot steam introduced into the bottom of the chamber through the first and second apertures provided in the floor of the chamber.

Optionally, the controller is arranged to control passage of the steam to and through the aperture in further combined cycles of the at least one combined cycle according to the temperature indicated by the temperature signal. In each combined cycle of the further combined cycles, the controller controls passage of the steam to and through the first and second apertures according to the low-pressure phase while the temperature indicated by the temperature signal rises above a lower temperature threshold, and controls passage of the steam to and through the first and second apertures according to the high-pressure phase when the temperature indicated by the temperature signal rises above a higher temperature threshold.

Hence, during the high-pressure phase of the first combined cycle, the controller monitors the temperature. When the controller determines that the temperature reaches the lower temperature threshold, the controller starts a new combined cycle and starts a new low-pressure phase. This new low pressure phase continues until the temperature reaches the higher temperature threshold, at which time the controller starts the high-pressure phase of new combined cycle. The controller may implement further combined cycles, by setting further lower and higher temperature thresholds. In this way, the controller cycles through a series of low-pressure and high-pressure phases such that a series of steam blankets are generated and then driven through the animal fodder. In this way, the heat provided by the steam spreads through animal fodder, from the bottom to the top.

The controller may implement a final low-pressure phase. For example, the controller may be arranged to control passage of the steam to and through the first and second apertures when the temperature indicated by the temperature signal rises above a final temperature threshold. In this final low-pressure phase, the controller may allow steam to pass from the first and second apertures into the chamber at the relatively low pressure. This allows any steam in the conduits to be purged, such that the apparatus is ready for the next steaming operation.

The controller may control the switching of steam being provided to the first and second apertures during high-pressure phases. For example, between the controller may be arranged in each high-pressure phase of each combined cycle to control passage of the steam to and through the first and second apertures in successive high pressure cycles while the temperature signal indicates that the controller should operate in that high-pressure phase. Moreover, the controller may be arranged to control passage of the steam to and through the first and second apertures in the high pressure phases of successive combined cycles of the least one combined cycle such that the value of the upper pressure threshold alternates between a first upper pressure threshold and a second, different upper pressure threshold. This means that different high-pressure phases exist for different temperature bands. Successive high-temperature phases alternate between a higher and lower upper pressure threshold such that the strength of the steam jets emerging from the first and second apertures alternates between successive high-pressure cycles.

As noted above, the floor may be provided with more than two apertures. For example, the floor may be provided with a third aperture. This third aperture may match the first and second apertures, i.e. the third aperture may have a third conduit and a third valve, and may operate in the same way as the first and second apertures. So, for example, the high-pressure phase may see steam jets provided sequentially from the first, second and third apertures, and then cycled further through the first, second and third apertures. In the low-pressure phases, steam may be provided to and through all of the first, second and third apertures simultaneously. This may all be true for however many apertures are provided in the floor.

Optionally, the apparatus is a hay steamer, and the body may define a chamber of a size to accommodate a standard sized hay bale, for example the chamber may have a size of at least <NUM> x <NUM> x <NUM>.

In a second aspect, there is provided a method of steaming animal fodder in an apparatus comprising a body defining a chamber with a floor on which the animal fodder rests. The method comprises introducing steam into the chamber at a relatively low pressure in a low-pressure phase, followed by introducing steam into the chamber at a relatively high pressure in a high-pressure phase. As noted above, the low-pressure phase may be used to gently introduce steam into the chamber such that a blanket of steam builds up, and the high-pressure phase may be used provide jets of steam that drive the blanket of steam upwards through the animal fodder which has been found to provide improved steaming of the animal fodder.

Steam may be introduced into the chamber beneath the animal fodder during the low-pressure phase and the high-pressure phase, for example through a series of apertures provided in the floor of the apparatus beneath the animal fodder.

Steam may be introduced through all the apertures at the same time during the low-pressure phase, and through one aperture at a time in the high-pressure phase. Passing the steam through only one aperture at a time is an easy way of increasing the pressure of the steam during the high-pressure phase, thereby providing jets of steam to drive upwards the blanket of steam created in the low-pressure phase. This method may be used in conjunction with monitoring the pressure of the steam in the steam supply, and releasing steam at a higher pressure in the high-pressure phase than in the low-pressure phase.

Optionally, during the high-pressure phase, the method may comprise measuring a pressure of the steam and, when the pressure exceeds a higher pressure threshold, releasing the steam to one of the apertures to produce a burst of steam from that aperture. When the pressure falls below a lower pressure threshold, the method may comprise preventing the steam from passing through any of the apertures, thereby allowing the pressure of the steam to increase. The method may further comprise one or more cycles of, when the pressure exceeds the higher pressure threshold once more, releasing the steam to a different aperture from the last aperture to supply steam to the chamber, and when the pressure falls below the lower pressure threshold, preventing the steam from passing through any of the apertures, thereby allowing the pressure of the steam to increase. In this way, steam jets may be provided from each of the apertures in turn. For example, the apertures may form a linear array, and the steam jets may be fired from the apertures in turn working along the linear array, before returning to the first aperture and repeating the cycle again and again.

Also, the method may comprise further cycles of introducing steam into the chamber at a relatively low pressure, followed by introducing steam into the chamber at a relatively high pressure. These cycles see successive blankets of steam generated at the bottom of the animal fodder in the low-pressure phases, before being driven through the animal fodder by the steam jets during the high-pressure phases.

Optionally, the method comprises measuring the rising temperature in the chamber, for example the temperature at to near the top of the chamber as it increases as more and more steam rises to the top of the chamber. Then, the cycles of introducing steam into the chamber at a relatively low pressure followed by introducing steam into the chamber at a relatively high pressure may be performed in response to the measured temperature according to a series of increasingly hot temperature bands. That is, the expected rise in temperature may be divided into a series of temperature bands. For example, a first temperature band may cover all temperatures up to <NUM>, followed by temperature bands spanning of <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> such that there is a final temperature threshold of <NUM>. A low-pressure phase may be performed during an initial temperature band, and a high-pressure phase may be performed during the next temperature band reached. Then, one or more further cycles maybe performed comprising performing a low-pressure phase during the next temperature band reached, and performing a high-pressure phase during the next temperature band reached. Alternating values for the higher pressure threshold may be used in successive high-pressure phases, such that more powerful steam jets are produced in every other high-pressure phase. The method may comprise a final low-pressure phase when a measured temperature rises above the final temperature threshold.

Optionally, the apparatus may be a hay steamer, and the method may be a method of steaming a hay bale. The hay bale may be placed on the floor of the hay steamer, so as to cover the apertures provided in the floor. A series of three hay bales may be provided along the length of the floor. The chamber may have a size of at least <NUM> x <NUM> x <NUM>. This allows the hay steamer to accommodate standard-sized hay bales.

In a third aspect, there is provided an apparatus for steaming animal fodder comprising a body defining a chamber in which animal fodder may be placed, the body comprising an upper part and a lower part configured to be placed together to form the chamber, the lower part including a floor on which the animal fodder is supported. The apparatus further comprises an aperture provided in the floor of the lower part and a conduit configured to carry steam to the aperture thereby allowing steam to pass into the chamber. The apparatus also comprises a temperature sensor to provide a temperature signal indicating the measured temperature to a controller. The controller is arranged to control passage of steam to and through the aperture according to the measured temperature indicated by the temperature signal.

Providing a temperature sensor allows for convenient temperature-based control of the apparatus. The temperature sensor may be arranged to measure the temperature in the chamber, such as at or close to the top of the chamber. For example, the temperature sensor may be mounted to the upper part of the body such as to the underside of the top of the upper part.

Optionally, the controller is arranged to follow a steaming program that provides steam to the chamber via the aperture while the measured temperature indicated by the temperature signal remains below a final temperature threshold, and to stop the steaming program responsive to the measured temperature indicated by the temperature signal rising to equal or exceed the final temperature threshold. Hence, an automatic shut off is provided that will stop the steaming once it is complete as indicated by final temperature threshold being reached. This arrangement is advantageous as it does not require a user to stay with the apparatus and monitor when the steaming is complete. Also, stopping the steaming program based on temperature is better than stopping the steaming program based on time as it is the final temperature of the animal fodder that determines the efficacy of the steaming rather than the amount of time to which the animal fodder is exposed to steam.

The controller may be arranged to control passage of steam to and through the aperture in a cycle, comprising a low-pressure phase followed by a high-pressure phase according to a series of increasingly hot temperature bands such that a low-pressure phase is performed when the measured temperature indicated by the temperature signal is within an initial temperature band and a high-pressure phase is performed when the measured temperature indicated by the temperature signal is within the next temperature band. In the low-pressure phase, the controller allows steam to pass to and through the aperture into the chamber at a relatively low pressure. In the high-pressure phase, the controller allows steam to pass to and through the aperture into the chamber at a relatively high pressure. The controller may be arranged to control passage of steam to and through the aperture in further cycles by performing a low-pressure phase during the next temperature band reached, and performing a high-pressure phase during the next temperature band reached.

The apparatus of the third aspect, and as modified in the preceding paragraphs, may comprise the controller which may be arranged to follow a first steaming program that provides steam to the chamber via the aperture while receiving the temperature signal from the temperature sensor, to determine a rate at which the measured temperature indicated by the temperature signal has risen and, if the rate is above a threshold rate, to begin following a second steaming program. This allows the controller to switch heating programs if the temperature rises in the chamber quickly. The rate of temperature rise may be quick where there is a small amount of animal fodder in the chamber to absorb heat from the steam. The rate may be determined in different ways. For example, the controller may be arranged to determine an amount of time elapsed when the measured temperature indicated by the temperature signal reaches a preset temperature value and, if the amount of time elapsed is below a time threshold value, to begin following the second steaming program. The time elapsed may be the amount of time elapsed since the controller started the first program or since the controller allowed steam to pass to and through the aperture. As another example, the controller may be arranged to determine the measured temperature indicated by the temperature signal at a preset amount of time and, if the measured temperature indicated by the temperature signal has risen above a temperature threshold value, to begin following a second steaming program. The preset amount of time may be the amount of time elapsed since the controller started the first program or since the controller allowed steam to pass to and through the aperture.

Optionally, the controller is arranged to control passage of steam to and through the aperture in a cycle, comprising a low-pressure phase in which the controller allows steam to pass to and through the aperture into the chamber at a relatively low pressure followed by a high-pressure phase in which the controller allows steam to pass to and through the aperture into the chamber at a relatively high pressure.

In the first program, the controller may be arranged to control passage of steam to and through the aperture in the low-pressure and high-pressure phases according to a series of increasingly hot temperature bands such that one or more low-pressure phases are performed when the measured temperature indicated by the temperature signal is within a certain temperature band or certain temperature bands, and such that one or more high-pressure phases are performed when the measured temperature indicated by the temperature signal is within a certain other temperature band or certain other temperature bands. The temperature bands may be defined such that the controller alternates between the low-pressure and high-pressure phases. The temperature bands may comprise a first temperature band up to <NUM>, followed by temperature bands spanning of <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> such that there is a final temperature threshold of <NUM>. The controller may be arranged to stop the steaming as soon as the final temperature threshold is reached, or the controller may be arranged to maintain the final temperature threshold for a period of time before stopping the steaming.

In the second program, the controller may be arranged to control passage of steam to and through the aperture in the low-pressure and high-pressure phases according to a series of time bands such that one or more low-pressure phases are performed when the time elapsed is within a certain time band or certain time bands, and such that one or more high-pressure phases are performed when the time elapsed is within a certain other time band or certain other time bands. The time bands may be defined such that the controller alternates between the low-pressure and high-pressure phases. Each time band may be <NUM> long. Therefore, if the rate of temperature rise is found to be high (i.e. in excess of the threshold rate), the controller switches from operating in a temperature controlled way to operating in a time controlled way.

The apparatus of the third aspect, and as modified in the preceding paragraphs, may comprise the controller which may be arranged to use the measured temperature indicated by the temperature signal to indicate that a descaling operation should be performed. For example, the controller may be arranged to determine if the measured temperature indicated by the temperature signal has risen to or above a maximum temperature threshold to indicate that a descaling operation should be performed. For example, the controller may be arranged to indicate that a descaling operation should be performed each time the measured temperature indicated by the temperature signal equals or exceeds the maximum temperature threshold. Alternatively, the controller may be arranged to indicate that a descaling operation should be performed if the measured temperature indicated by the temperature signal equals or exceeds the maximum temperature threshold more than a predetermined number of times within a certain time period. Conveniently, this helps ensure the apparatus is descaled only when needed, rather than relying on a user to set descaling manually which may see this done too frequently or too infrequently. The apparatus may comprise a boiler operable to produce the steam, and the temperature sensor may be arranged to measure the temperature of a heating element of the boiler. The descaling operation may effect descaling of the heater element in the boiler, for example by heating the heating element to a raised temperature (raised relative to normal operation during steaming) and/or heating the element for a prolonged time (prolonged relative to normal operation during steaming).

In a fourth aspect, there is provided a method of steaming animal fodder using an apparatus comprising a body forming a chamber with a floor on which the animal fodder rests. The apparatus further comprises an aperture provided in the floor of the lower part and a conduit configured to carry steam to the aperture thereby allowing steam to pass into the chamber. A temperature sensor provides a temperature signal indicating the measured temperature to a controller. The controller controls passage of steam to and through the aperture according to the measured temperature indicated by the temperature signal.

Providing a temperature sensor allows for convenient temperature-based control of the apparatus. The temperature sensor may measure the temperature in the chamber, such as at or close to the top of the chamber. For example, the temperature sensor may be mounted to the upper part of the body such as to the underside of the top of the upper part.

Optionally, the controller follows a steaming program that provides steam to the chamber via the aperture while the measured temperature indicated by the temperature signal remains below a final temperature threshold. When the measured temperature indicated by the temperature signal rises to equal or exceed the final temperature threshold, the controller stops the steaming program.

The method may further comprise the controller controlling passage of the steam to and through the aperture in a cycle, comprising a low-pressure phase followed by a high-pressure phase according to a series of increasingly hot temperature bands such that a low-pressure phase is performed when the measured temperature indicated by the temperature signal is within an initial temperature band and a high-pressure phase is performed when the measured temperature indicated by the temperature signal is within the next temperature band. In the low-pressure phase, the controller allows steam to pass to and through the aperture into the chamber at a relatively low pressure. In the high-pressure phase, the controller allows steam to pass to and through the aperture into the chamber at a relatively high pressure. The controller may control passage of steam to and through the aperture in further cycles by performing a low-pressure phase during the next temperature band reached, and performing a high-pressure phase during the next temperature band reached.

The method of the fourth aspect, and as modified in the preceding paragraphs, may comprise the controller following a first steaming program that provides steam to the chamber via the aperture while receiving the temperature signal from the temperature sensor, determining a rate at which the measured temperature indicated by the temperature signal has risen and, if the rate is above a threshold rate, beginning to follow a second steaming program. The rate may be determined in different ways. For example, the controller may determine an amount of time elapsed when the measured temperature indicated by the temperature signal reaches a preset temperature value and, if the amount of time elapsed is below a time threshold value, the controller may begin following the second steaming program. The time elapsed may be the amount of time elapsed since the controller started the first program or since the controller allowed steam to pass to and through the aperture. As another example, the controller may determine the measured temperature indicated by the temperature signal at a preset amount of time and, if the measured temperature indicated by the temperature signal has risen above a temperature threshold value, the controller may begin following a second steaming program. The preset amount of time may be the amount of time elapsed since the controller started the first program or since the controller allowed steam to pass to and through the aperture.

The controller may control passage of steam to and through the aperture in a cycle, comprising a low-pressure phase in which the controller allows steam to pass to and through the aperture into the chamber at a relatively low pressure followed by a high-pressure phase in which the controller allows steam to pass to and through the aperture into the chamber at a relatively high pressure. In the first program, the controller may control passage of steam to and through the aperture in the low-pressure and high-pressure phases according to a series of increasingly hot temperature bands such that one or more low-pressure phases are performed when the measured temperature indicated by the temperature signal is within a certain temperature band or certain temperature bands, and such that one or more high-pressure phases are performed when the measured temperature indicated by the temperature signal is within a certain other temperature band or certain other temperature bands. The temperature bands may be defined such that the controller alternates between the low-pressure and high-pressure phases. In the second program, the controller may control passage of steam to and through the aperture in the low-pressure and high-pressure phases according to a series of time bands such that one or more low-pressure phases are performed when the time elapsed is within a certain time band or certain time bands, and such that one or more high-pressure phases are performed when the time elapsed is within a certain other time band or certain other time bands. The time bands may be defined such that the controller alternates between the low-pressure and high-pressure phases. Therefore, if the rate of temperature rise is found to be high (i.e. in excess of the threshold rate), the controller switches from operating in a temperature controlled way to operating in a time controlled way.

The aperture may be one of a plurality of apertures provided in the floor of the lower part. Each aperture may have an associated conduit configured to carry steam to the aperture thereby allowing steam to pass into the chamber. The floor may comprise two adjacent zones, each zone including one or more apertures of the plurality of apertures. For example, the length of the floor may be divided into two zones, and each zone may correspond (or substantially correspond) to a half of the floor. In the first program, the controller may control passage of steam to and through the apertures of both the first and second zones. In the second program, the controller may control passage of steam to and through only the apertures of the first zone.

The method of the fourth aspect, and as modified in the preceding paragraphs, may comprise the controller using the measured temperature indicated by the temperature signal to indicate that a descaling operation should be performed. For example, the controller may determine a rate at which the measured temperature indicated by the temperature signal has risen and, if the rate is above a threshold rate, indicate that a descaling operation should be performed. The apparatus may comprise a boiler operable to produce the steam, and the temperature sensor may be arranged to measure the temperature of a heating element of the boiler. The descaling operation may effect descaling of the heater element in the boiler, for example by heating the heating element to a raised temperature (raised relative to normal operation during steaming) and/or heating the element for a prolonged time (prolonged relative to normal operation during steaming).

In a fifth aspect, there is provided an apparatus for steaming animal fodder comprising a body defining a chamber in which animal fodder may be placed, the body comprising an upper part and a lower part configured to be placed together to form the chamber, the lower part including a floor on which the animal fodder is supported. The apparatus further comprises a boiler operable to boil water and create steam, an aperture provided in the floor of the lower part and a conduit configured to carry steam from the boiler to the aperture thereby allowing steam to pass into the chamber. The apparatus also comprises a showerhead and a hose connected or configured to be connected to the boiler to allow water heated by the boiler to be supplied to the showerhead.

In this way, the apparatus may also be used to shower an animal such as a horse, using water heated by the boiler of the apparatus.

The showerhead and the hose may be permanently connected to the apparatus or may be configured to be connected and disconnected to the apparatus, for example whenever a user wants to use the showerhead. The hose may be connected or connectable to the conduit leading from the boiler to the aperture. Alternatively, the apparatus may be provided with a further conduit ending in an external outlet that discharges externally to the chamber. The further conduit may connect the boiler to the external outlet. Optionally, the external outlet may be arranged to provide a pressure relief outlet for the boiler if the pressure in the boiler rises too high. The external outlet may also provide a connection for the hose thereby providing a path for water to flow from the boiler to the showerhead, whether or not it is arranged to provide a pressure relief outlet for the boiler. The boiler may comprise a heater element and a temperature sensor operable to measure the temperature of water in the boiler. The apparatus may comprise a controller operable to control the heater element to heat the water in the boiler to a target temperature and then to maintain the water in the boiler at the target temperature.

Ina sixth aspect, there is provided a method of operating the apparatus of the fifth aspect (including as modified with any of the optional features described above) to provide a shower for an animal. The method comprises operating a heating element of the boiler to heat water in the boiler, and to provide the heated water to the showerhead. The boiler may comprise a heater element and a temperature sensor operable to measure the temperature of water in the boiler. The apparatus may comprise a controller, and the method may comprise the controller controlling the heater element to heat the water in the boiler to a target temperature and then to maintain the water in the boiler at the target temperature. The boiler may also be provided with a pressure sensor to sense the pressure in the boiler (either water pressure or steam pressure), and the controller may be operable to open and close an inlet valve to the boiler to ensure a pressure at or above a target pressure.

In order that the invention can be more readily understood, reference will now be made by way of example only, to the accompanying drawings in which:.

<FIG> shows a hay steamer <NUM> according to an embodiment of the invention. Although described as a hay steamer <NUM>, it will be understood that the hay steamer <NUM> is not limited to steaming hay. For example, the hay steamer <NUM> may be used for steaming other types of animal fodder such as straw, silage and haylage. The hay steamer <NUM> may also be used for growing plants, fruits and vegetables. For example, the hay steamer <NUM> may be used to pasteurise straw or other substrate when growing mushrooms.

The hay steamer <NUM> resembles a wheeled-trunk, and has a size suitable for containing a standard-sized hay bale <NUM>. In normal use, the hay steamer <NUM> rests on a pair of wheels <NUM> at one end and a pair of feet <NUM> at the other end (see <FIG> and <FIG>). A handle <NUM> (see <FIG>) is provided at the same end as the feet <NUM>. The handle <NUM> may be used to lift the end of the hay steamer <NUM> so that the hay steamer <NUM> may be rolled on its wheels <NUM> from one location to another. A pair of skid plates <NUM> are provided on the feet <NUM>. Returning to <FIG>, the hay steamer 100A is provided with a user interface <NUM> having a display <NUM> and control buttons <NUM>.

As seen more clearly in <FIG> and <FIG>, the hay steamer <NUM> has a body <NUM> comprising a lower part <NUM> and an upper part <NUM>. Both the lower part <NUM> and the upper part <NUM> are generally wedge shaped. The lower part <NUM> and the upper part <NUM> are joined by a pair of hinges <NUM> such that the upper part <NUM> may be rotated up and clear of the lower part <NUM> to open the hay steamer <NUM> and provide access to the hay steamer <NUM> for loading and unloading a hay bale <NUM>.

The lower part <NUM> comprises a floor <NUM> for supporting a hay bale <NUM>, and sloping side walls <NUM> that join a high back wall <NUM> of the lower part <NUM>. The lower part <NUM> has an open front with no lip to the front of the floor <NUM>. This configuration of the lower part <NUM> provides easy access to the interior <NUM> of the hay steamer <NUM> through a large aperture defined by the lower part <NUM> and the upper part <NUM> of the hay steamer <NUM> when opened. In particular, the absence of a front wall or even a lip at the front of the floor <NUM> makes it much easier to load and unload a hay bale <NUM> than the prior art hay steamer <NUM> described above. A further advantage is that the lack of front wall or lip to the floor <NUM> allows water to drain freely from the hay steamer <NUM>. The floor <NUM> has a slight slope (e.g. <NUM>°) from back to front to assist further this water drainage.

The upper part <NUM> has a wedge shape that complements the shape of the lower part <NUM>, with a top wall <NUM> and sloping side walls <NUM> that extend from a high front wall <NUM> to meet a shallow back wall <NUM>. The pair of hinges <NUM> are provided on the back wall <NUM> of the lower part <NUM> and the back wall <NUM> of the upper part <NUM>. Each hinge <NUM> comprises alternating knuckles and an interlocking metal pin that passes through the knuckles. In this embodiment, the knuckles are formed integrally with the lower part <NUM> and the upper part <NUM>. The complementary wedge shapes of the lower part <NUM> and the upper part <NUM> means that the lower part <NUM> and the upper part <NUM> close to abut each other and form the general trunk shape of the hay steamer <NUM>.

<FIG> and <FIG> show that the upper part <NUM> is provided with a resilient seal <NUM> that extends around the aperture formed by the upper part <NUM>. The seal <NUM> is retained within a groove (not shown) that extends along lower surfaces of the back wall <NUM>, the side walls <NUM> and the front wall <NUM>. When the upper part <NUM> is in the closed position shown in <FIG>, the seal <NUM> is seated in a complementary groove (not shown) provided in the upper surfaces of the lower part <NUM>. The seal <NUM> prevents steam from escaping from the interior <NUM> of the hay steamer <NUM> during steaming cycles.

The hay steamer <NUM> may be secured shut using fasteners <NUM> provided on the front of the hay steamer <NUM>. In this embodiment, the fasteners <NUM> comprise a pair of straps <NUM> that hang from the upper part <NUM> and that are provided with clasps <NUM> that hook around catches <NUM> provided in the lower part <NUM>, as can be seen best from <FIG> and <FIG>. The straps <NUM> have a cam handle that allows the clasps <NUM> to be drawn up against the catches <NUM> into firm engagement. The straps <NUM> pass through a tri-glide slide (webbing slide) that allows their length to be adjusted, for example to adjust the force required to secure the hay steamer <NUM> shut and to accommodate any stretching that may occur over time.

The upper part <NUM> of the hay steamer <NUM> is held in the open position by gas struts <NUM> provided on the sides of the hay steamer <NUM>. These gas struts <NUM> may also assist in moving the upper part <NUM> to the open position and in allowing the upper art <NUM> to close gently. The bottom of each gas strut <NUM> is received within a respective slot <NUM> provided in one of the side walls <NUM> of the lower part <NUM> of the hay steamer <NUM> where it is pivotably mounted, and the top of each gas strut <NUM> is pivotably attached to the upper part <NUM>.

The pair of wheels <NUM> are provided at opposite corners of the left end of the lower part <NUM> of the hay steamer <NUM> (when viewed from in front, although the wheels may be provided at the right end), such that the wheels <NUM> may support the hay steamer <NUM> when resting both horizontally and vertically. The wheels <NUM> are connected by an axle <NUM>. A pair of rests <NUM> project from the left-hand side wall <NUM> of the upper part <NUM> above the wheels <NUM>, such that the hay steamer <NUM> is supported on the wheels <NUM> and the rests <NUM> when it is stored vertically (for example, to provide a smaller footprint during storage as shown in <FIG>).

<FIG> and <FIG> show the hay steamer <NUM> with the upper part <NUM> raised in the open position, and with a hay bale <NUM> loaded into the interior <NUM> of the hay steamer <NUM>. As can be seen, the interior <NUM> of the hay steamer <NUM> forms a chamber <NUM> shaped and sized to accommodate a standard-sized hay bale <NUM>. The hay bale <NUM> rests on the floor <NUM> of the lower part <NUM> so as to cover a set of apertures provided in the floor <NUM> that function as a set of steam vents <NUM>. In this embodiment, three steam vents <NUM> are equally spaced apart longitudinally, along the centreline of the chamber <NUM>. The steam vents <NUM> have edges <NUM> that are slightly raised from the floor <NUM>, see <FIG> and <FIG>. Each steam vent <NUM> also sits within a compartment <NUM>, and the three compartments <NUM> are formed by a raised frame <NUM> provided in the floor <NUM>. The hay bale <NUM> rests on the frame <NUM>, but not the edges <NUM> of the steam vents <NUM> which do not extend so high from the floor <NUM> (as best seen in <FIG>). This arrangement allows steam to spread before entering the hay bale <NUM>. Small gaps are provided in the front of the frame <NUM> to provide channels <NUM> linking the compartments to the front of the floor <NUM>. This allows condensed steam to exit the compartments <NUM> during steaming, which prevents the hay bale <NUM> from sitting in puddles of water that would otherwise form in the compartments <NUM>. The channels <NUM> also allow water to drain from the compartments <NUM> when the hay steamer <NUM> is being cleaned, for example when washing the interior <NUM> of the hay steamer <NUM> using a hose.

The frame <NUM> is of a low height to ease placing hay bales <NUM> into the hay steamer <NUM>. In particular, the absence of a lip at the front of the floor <NUM> means that hay bales <NUM> need be raised only a small height before being placed on the floor <NUM> and slid into position over the steam vents <NUM>. This may be contrasted to the prior art steamer of <CIT> where a hay bale <NUM> must be lifted high to clear a tall front wall before being dropped onto lances extending from the floor <NUM>. Once the hay bale <NUM> has settled onto the lances, there is little if any opportunity to adjust the position of the hay bale <NUM>. In contrast, <FIG> and <FIG> herein show that a hay bale <NUM> need only be placed onto the floor <NUM> before being slid into position to cover the three steam vents <NUM>. Hence, no precision is required when loading a heavy hay bale <NUM> into the hay steamer <NUM>, much to the benefit of a user. Unloading a hay bale <NUM> from the hay steamer <NUM> of <FIG> and <FIG> is even easier. The absence of lances and a front wall (or even a lip) at the front of the floor <NUM> ensures that a hay bale <NUM> may be simply slid out of the hay steamer <NUM> without any lifting being required.

As shown in <FIG> and <FIG>, the underside <NUM> of the lower part <NUM> of the hay steamer <NUM> is provided with a recess <NUM> covered by the sump guard <NUM>. The recess <NUM> is used to house a water tank <NUM>, a boiler <NUM>, a pump <NUM> and a controller <NUM> (see also the detail of <FIG>). Hoses <NUM>, 178a, 178b connect the water tank <NUM> to the pump <NUM>, the pump <NUM> to the boiler <NUM>, the boiler <NUM> to the three steam vents <NUM>, and the boiler <NUM> to an external outlet <NUM>. Wires <NUM> connect the controller <NUM> to a power inlet <NUM> (see <FIG>), the boiler <NUM>, the pump <NUM>, a thermocouple <NUM> provided in the chamber <NUM> (see <FIG>), a safety switch <NUM> (See <FIG>), and to the user interface <NUM> provided on the upper part <NUM> of the hay steamer <NUM>.

The water tank <NUM> is located in a bay <NUM> formed in the underside <NUM> of the lower part <NUM> and is provided with a handle <NUM> such that the water tank <NUM> may be easily removed for refilling. In this embodiment the water tank <NUM> may be filled with up <NUM> litres of water, and then pushed back into the bay <NUM> where it is positively held in place by an interference fit between a protrusion <NUM> provided on the underside <NUM> of the tank <NUM> and the axle <NUM> that connects the wheels <NUM>. The tank <NUM> is provided with a connector <NUM> (such as a push fit connector) that co-operates with a complementary push fit connection <NUM> provided at the end of a hose 178a that extends to the boiler <NUM>. A feeder hose <NUM> also connects to the complementary push fit connection <NUM>, and the feeder hose <NUM> extends into the water tank <NUM> through the filling hole provided in the push fit connector <NUM>. The end 179a of the hose <NUM> is provided with a downward bend such that it draws water from the bottom of the water tank <NUM>. The complementary push fit connection <NUM> provided on the hose 178a may also be used to provide a direct connection to a hose pipe (not shown) for when a suitable mains water supply is available. The feeder hose <NUM> is disconnected and a hose pipe provided with the common type of push fit connector may be connected to the hose 178a via the complementary push fit connection <NUM>.

In either arrangement, water from the water tank <NUM> or the hose pipe flows to the pump <NUM> via hose 178a, and then onto the boiler <NUM>. Water flow to the boiler <NUM> is controlled by the controller <NUM> operating the pump <NUM> and an inlet valve (not shown). A check valve can be used to prevent water flowing back into the pump <NUM>. Steam created in the boiler <NUM> flows to the steam vents <NUM> from three outlets of the boiler <NUM>, from where it passes through the hay bale <NUM>, thereby killing spores and dust particles in the hay bale <NUM>. Steam delivery is controlled by the controller <NUM> using a valve set <NUM> located at the outlets of the boiler <NUM> to the steam vents <NUM> to allow any or all of the steam vents <NUM> to be selected.

To steam a hay bale <NUM>, a user will first open the hay steamer <NUM> by lifting the front of the upper part <NUM> on its gas struts <NUM>, using a handle <NUM> provided for this purpose. The upper part <NUM> is kept open by the gas struts <NUM>, such that the user's hands are free to place the hay bale <NUM> on the floor <NUM> of the lower part <NUM>, and to slide the hay bale <NUM> into position on the frame <NUM> to cover the steam vents <NUM>.

The user may then close the upper part <NUM> and secure the straps <NUM> to seal the chamber <NUM>. The user may check that the water tank <NUM> contains water or that water is supplied by a hose pipe to the mains connector. However, a warning is provided on the display <NUM> if the controller <NUM> detects that the boiler <NUM> is empty (and operation of the boiler <NUM> is disabled).

The user can select a steaming cycle by pressing an appropriate start button <NUM> provided on the user interface <NUM>. This sends a signal to the controller <NUM> to pump water to the boiler <NUM>, and turn on the boiler <NUM> to boil the water and create steam. As the steam is produced, the pressure in the boiler <NUM> is monitored by the controller <NUM>. When the pressure reaches a threshold pressure, the controller <NUM> operates the valve set to allow steam to flow to one or more of the steam vents <NUM> and into the hay bale <NUM>.

The hot steam will rise through the hay bale <NUM>, thereby removing and killing the bacteria, mould spores, fungi and dust particles present in the hay bale <NUM>. Steam will rise to the top of the chamber <NUM>, causing the temperature at the top of the chamber <NUM> to rise steadily. This rising temperature is measured by the thermocouple <NUM> during the steaming cycle. Once the temperature measured by the thermocouple <NUM> reaches a threshold temperature, the controller <NUM> automatically switches off the boiler <NUM> and pump <NUM>. Advantageously, the automatic switch-off function allows the user to start the hay steamer <NUM> and then leave without the risk of the boiler <NUM> boiling dry, therefore avoiding damage to the hay steamer <NUM>. A button <NUM> on the user interface <NUM> allows the user to stop steaming at any time, if so desired. At the end of steaming, a flush is performed to relive any pressure remaining in the boiler <NUM> by opening a valve of the valve set <NUM> that connects the boiler <NUM> to the external outlet <NUM> via hose 178b. The external outlet <NUM> discharges steam to atmosphere from a safe location on the underside <NUM> of the hay steamer <NUM>, see <FIG>. The external outlet <NUM> may also be used to relieve pressure in the boiler <NUM> should the boiler <NUM> and/or controller <NUM> malfunction and allow too great a pressure to build up in the boiler <NUM>.

To retrieve the treated hay bale <NUM>, the user releases the straps <NUM> and opens the upper part <NUM>. The treated hay bale <NUM> may then be easily slid across the floor <NUM> and out of the hay steamer <NUM>, ready for use. There is also a safety switch <NUM> positioned on the top of the back wall <NUM> of the lower part <NUM> that detects when the hay steamer <NUM> is open. The safety switch <NUM> may be any suitable type, such as a mechanical contact switch or a magnetic, electrical or optical sensor. The safety switch <NUM> is connected to the controller <NUM> via wires <NUM>. If the safety switch <NUM> detects that the hay steamer <NUM> is open, the controller <NUM> sends a signal to turn off the boiler <NUM> and/or shut the valve set (not shown) such that no steam can pass through the steam vents <NUM> and into the chamber <NUM>. This ensures that the steaming cycle can only run when the hay steamer <NUM> is closed.

<FIG> shows how the controller <NUM> may implement a method <NUM> of steaming a hay bale <NUM>. The method <NUM> starts at <NUM> where the controller <NUM> starts a low-pressure phase <NUM> while monitoring the temperature in the chamber <NUM> as indicated by the temperature signal received from the thermocouple <NUM>. In this and subsequent low-pressure phases <NUM>, the controller <NUM> supplies all three steam vents <NUM> with low-pressure steam <NUM> such that low-pressure steam <NUM> enters the hay bale <NUM> from all three steam vents <NUM>. The low-pressure steam <NUM> enters the chamber <NUM> and hence the hay bale <NUM> at low pressure. This creates a "blanket" of steam <NUM> in the hay bale <NUM>, as shown in <FIG>.

At <NUM>, the controller <NUM> determines whether the temperature in the chamber <NUM> indicated by the thermocouple <NUM> has risen to <NUM>. The controller <NUM> continues to wait until the controller <NUM> determines that the temperature has risen to <NUM> at a subsequent temperature check <NUM>. When, at <NUM>, the controller <NUM> determines that the temperature has risen to <NUM>, the controller <NUM> switches to a first type of high-pressure phase 212a, indicated as high-pressure phase (a) in the figures. An example of high-pressure phase (a) 212a is provided in <FIG>, and will be described in more detail below. In this and subsequent high-pressure phases 212a, 212b, the controller <NUM> provides high-pressure steam <NUM> to one steam vent <NUM> at a time. The higher pressure of the steam <NUM> as it passes from each steam vent <NUM> in turn causes steam jets <NUM> that drive the steam blanket <NUM> produced in the preceding low-pressure phase <NUM> upwardly through the hay bale <NUM>.

The controller <NUM> then alternates through successive low-pressure phases <NUM> and high-pressure phases 212a, 212b. The high-pressure phases 212a, 212b also alternate, between the first type of high-pressure phase 212a and a second type of high-pressure phase 212b. The controller <NUM> switches between low-pressure phases <NUM> and high-pressure phases 212a, 212b based on the temperature in the chamber <NUM> as tested at steps <NUM>. As can be seen from <FIG>, the controller <NUM> switches from one phase to the next at temperatures of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM>. Smaller temperature bands are used at higher temperatures to reflect the increased difficulty in raising the temperature of the hay bale <NUM> when at these higher temperatures. As a result, the time spent operating in each temperature band is more similar. The final temperature threshold of <NUM> sees the controller <NUM> implement a final low-pressure phase <NUM> before ending the method <NUM> at <NUM>. The method <NUM> may end with the controller <NUM> flushing the boiler <NUM> by opening a valve to the external outlet <NUM>, as described above.

In each low pressure phase <NUM>, the controller <NUM> allows steam from the boiler <NUM> to pass to all three steam vents <NUM> continuously. This continuous supply of steam to all three steam vents <NUM> simultaneously ensures that low pressure steam <NUM> is delivered to the hay bale <NUM>. Pressures of around <NUM> bar to <NUM> bar may be used. The low pressure steam <NUM> exits the steam vents <NUM> and passes into the hay bale <NUM>, both directly and also after spreading thorough the compartments <NUM> beneath the hay bale <NUM>.

<FIG> shows an example of the high-pressure phases 212a, and <FIG> shows an example of the high-pressure phases 212b. A high pressure phase 212a begins at pressure rise test step <NUM> where the controller <NUM> determines whether the pressure in the boiler <NUM> is more than an upper pressure threshold of <NUM> bar. If not, the controller <NUM> waits, and continues to do so until a test at <NUM> indicates the pressure to have exceeded <NUM> bar. Then, the controller <NUM> releases steam at <NUM> by directing high pressure steam <NUM> to the first steam vent <NUM> only, which is the left steam vent <NUM> in this embodiment. As the steam is delivered to only a single steam vent <NUM>, a higher steam pressure is achieved which, as shown in <FIG>, causes a steam jet <NUM> to fire from the left steam vent <NUM>. Little if any steam spreads through the compartment <NUM> before entering the hay bale <NUM>. The steam jet <NUM> drives the portion of the steam blanket <NUM> above the left steam vent <NUM> up through the hay bale <NUM>. This continues until the controller <NUM> detects at pressure drop test step <NUM> that the pressure in the boiler <NUM> has dropped below <NUM> bar. When the pressure drops below <NUM> bar, at <NUM> the controller <NUM> shuts off the steam supply from the boiler <NUM> so that the pressure in the boiler <NUM> may rise again.

The controller <NUM> then performs further pressure rise tests <NUM> while waiting until the pressure rises above the upper pressure threshold of <NUM> bar. The controller <NUM> then directs steam to the second steam vent <NUM> only, which is the middle steam vent <NUM> in this embodiment. As shown in <FIG>, this causes a steam jet <NUM> to fire from the middle steam vent <NUM> to drive the middle portion of the steam blanket <NUM> up through the hay bale <NUM>. This continues until the controller <NUM> detects at the pressure drop test step <NUM> that the pressure in the boiler has dropped below <NUM> bar. When the pressure drops below <NUM> bar, at <NUM> the controller <NUM> shuts off the steam supply once more so that the pressure in the boiler <NUM> may rise again.

The controller <NUM> then performs further pressure rise tests <NUM> while waiting until the pressure rises above the upper pressure threshold of <NUM> bar. The controller <NUM> then directs steam to the third steam vent <NUM> only, which is the right steam vent 154r in this embodiment. As shown in <FIG>, this causes a steam jet <NUM> to fire from the right steam vent 154r and to drive the right-side portion of the steam blanket <NUM> up through the hay bale <NUM>. This continues until at <NUM> the controller <NUM> detects that the pressure in the boiler <NUM> has dropped below <NUM> bar. When the pressure drops below <NUM> bar, at <NUM> the controller <NUM> shuts off the steam supply once more so that the pressure in the boiler <NUM> may rise again.

At <NUM>, <FIG> shows that after the right steam vent 154r has fired, the controller <NUM> returns to another cycle of firing the first, second and third steam vents <NUM> in turn, and so on until the controller <NUM> moves to the next low-pressure phase <NUM> as determined by the temperature in the chamber <NUM> rising above the next threshold. <FIG> show the next low-pressure phase <NUM> and start of the following high-pressure phase <NUM>. The figures show a second steam blanket <NUM>' formed beneath the first steam blanket <NUM>, and the two steam blankets <NUM>, <NUM>' being driven through the hay bale <NUM>.

Inspection of <FIG> will show that high-pressure phase 212b is the same as high-pressure phase 212a shown in <FIG>, except that the controller <NUM> compares the pressure in the boiler <NUM> to a higher upper pressure threshold of <NUM> bar. This higher pressure results in more powerful steam jets <NUM> that drive the steam blanket <NUM> further through the hay bale <NUM>.

<FIG> shows a development of the method <NUM> of <FIG> that sees the controller <NUM> adopt a different mode of operation when a small load is placed in the hay steamer <NUM>, for example a half-bale rather than a full-sized bale <NUM>. When a small load is steamed, the temperature in the chamber <NUM> rises more quickly than for a full load, and the controller <NUM> can detect this and switch to a second mode of operation.

The method <NUM> of <FIG> starts at <NUM> in the same way as for the method <NUM> of <FIG>, except that the controller <NUM> starts a timer (shown at <NUM>) when commencing the first low-pressure phase <NUM>. The controller <NUM> then switches to the first high-pressure phase 212a when the temperature reaches <NUM>, as was also done in the method <NUM>. However, after the controller <NUM> has determined that the temperature has risen to <NUM>, the controller <NUM> stops the timer and checks at <NUM> to see if the time elapsed in less than a threshold time. This threshold time is set to <NUM> seconds in this embodiment. If the time elapsed in more than <NUM> seconds, the controller <NUM> assumes a full load is present and continues with the temperature-based steaming process as already described with reference to <FIG>. Alternatively, if the time elapsed in less than <NUM> seconds, the controller <NUM> assumes a part-load is present and starts a time-based steaming process shown in the left-hand column of <FIG>.

<FIG> shows that the time-based steaming process used for partial loads is similar to the temperature-based steaming process used for full loads in that the controller <NUM> switches between low-pressure phases <NUM> and high-pressure phases 212a, 212b. Also, the controller <NUM> alternates between high-pressure phases 212a and high-pressure phases 212b as is also done for full loads. However, the controller <NUM> switches modes every <NUM> seconds. That is, at the start of each phase, the controller <NUM> starts the timer and continues with that phase until the timer reaches <NUM> seconds as detected at time check steps <NUM>, at which time the controller <NUM> moves on to the next phase. The controller <NUM> switches in this way <NUM> times, and finishes on a low-pressure phase <NUM>. A time-based control is used rather than a temperature-based control due to the potential for one steam vent <NUM> not to be covered by a hay bale <NUM>. The uncovered steam vent <NUM> will discharge directly into the chamber <NUM>, such that the temperature measured by the thermocouple <NUM> rises more quickly relative to the temperature in the hay bale <NUM>, when compared to a full bale <NUM> where all steam vents <NUM> discharge into the hay bale <NUM> and the temperature in the chamber matches well the temperature in the hay bale <NUM>.

The time-based steaming used for half-loads sees the steaming complete sooner than the temperature-based steaming used for full loads and at a chamber <NUM> temperature of closer to <NUM>. For example, the time-based steaming used for half-loads may complete in <NUM> minutes, whereas the temperature-based steaming used for full loads may complete in <NUM> minutes.

The controller <NUM> may also automatically stop the steaming process if the temperature in the chamber <NUM> indicated by the thermocouple <NUM> rises above a maximum allowed temperature. The controller <NUM> may monitor this condition throughout either method <NUM> or <NUM> described above, either continuously or periodically. When the maximum allowed temperature is reached, the controller <NUM> may switch off the boiler and/or close valves to prevent steam escaping from the steam vents <NUM> into the chamber <NUM>. As described above, the controller <NUM> may open a valve to the external outlet <NUM> to relive the pressure in the boiler <NUM>.

The controller <NUM> may also monitor the boiler <NUM> to determine when a heater element of the boiler <NUM> should be descaled. For example, a temperature sensor may measure the temperature of the heating element. The controller <NUM> may then determine if the temperature indicated by the temperature sensor has risen to or above a maximum temperature limit to indicate that a descaling operation should be performed. The controller <NUM> may indicate that a descaling operation should be performed each time the measured temperature equals or exceeds the maximum temperature threshold. Alternatively, the controller <NUM> may indicate that a descaling operation should be performed if the measured temperature indicated by the temperature signal equals or exceeds the maximum temperature threshold more than a predetermined number of times within a certain time period. A descaling operation may effect descaling by heating the heating element to a raised temperature (raised relative to normal operation during steaming) and/or heating the element for a prolonged time (prolonged relative to normal operation during steaming).

A further mode of operation is shown in <FIG> in which the hay steamer <NUM> is used to supply heated water to a showerhead. The heated water may be used to clean an animal such as a horse.

As shown in <FIG>, a showerhead <NUM> fitted to a hose <NUM> is supplied with the hay steamer <NUM> (although may be omitted). For the sake of clarity, only a short length of hose <NUM> is shown in <FIG> and in practice a longer hose <NUM> would be provided with the hay steamer <NUM>. The showerhead <NUM> and hose <NUM> may be of any standard type commonly available. The end of the hose <NUM> distant from the showerhead <NUM> may be provided with a connector <NUM>, such as one of the push fit connectors commonly available for hoses. The external outlet <NUM> may also comprise a push fit connection such that the showerhead <NUM> and hose <NUM> may be connected to the hose 178b. To facilitate this, the external outlet <NUM> may be secured to the underside <NUM> of the hay steamer <NUM> in a notch <NUM> as a friction fit (see <FIG>). When the showerhead <NUM> is required for use, the external outlet <NUM> may be pulled free from the notch <NUM> and the hose <NUM> of the showerhead <NUM> connected to the external outlet <NUM>. The controller <NUM> may direct hot water from the boiler <NUM> to hose 178b and hence to the showerhead <NUM> by opening the appropriate valve of the valve set <NUM>.

The method <NUM> starts at <NUM> when a user selects the shower mode of operation using the user interface <NUM>. At <NUM>, the controller <NUM> then checks the pressure in the boiler <NUM> to test whether the pressure equals or exceeds a target pressure. In this embodiment, the target pressure is <NUM> bar, although other values may be used. Initially, this is unlikely to be the case. If the pressure is less than <NUM> bar, the controller <NUM> opens an inlet valve to the boiler <NUM> at <NUM> (if not already open), and loops back to <NUM> to check the pressure once more. Opening the inlet valve allows more water to enter the boiler <NUM>, and a greater pressure to be reached.

When the controller <NUM> determines the pressure to be at or above <NUM> bar at step <NUM>, the method <NUM> proceeds by the controller <NUM> closing the inlet valve at <NUM> (if not already closed). Then, at <NUM>, the controller <NUM> checks the temperature of water in the boiler <NUM> to test whether the temperature equals or exceeds a target temperature. In this embodiment, the target temperature is <NUM>, although other values may be used. Initially, this is unlikely to be the case. If the temperature is less than <NUM>, the controller <NUM> turns on the heater element of the boiler <NUM> at <NUM> (if not already on) to raise the temperature of water in the boiler <NUM>, and loops back to <NUM> to check the temperature once more.

When the controller <NUM> determines the water temperature to be at or above <NUM> at step <NUM>, the method <NUM> proceeds by the controller <NUM> turning off the heater element of the boiler <NUM> at <NUM> (if not already off). Then, at <NUM>, the controller <NUM> opens the valve of the valve set <NUM> (if not already open) that connects the boiler <NUM> to the hose 178b and the external outlet <NUM> such that hot water can flow to the external outlet <NUM> and to the connected hose <NUM> and showerhead <NUM>.

The controller <NUM> monitors the pressure and temperature while the method <NUM> is ongoing by virtue of the return loop linking step <NUM> to <NUM> in <FIG>. At step <NUM>, the controller <NUM> determines whether the user has ended the shower mode of operation via the user interface <NUM> (and, if so, ends the method <NUM> at <NUM>). Assuming the method <NUM> is ongoing because it has not yet been ended by the user, the method returns to <NUM> where the controller <NUM> tests the pressure in the boiler <NUM> once more and adjusts the inlet valve as necessary at steps <NUM> and/or <NUM>. The controller <NUM> also tests the water temperature once more and adjusts the heater element of the boiler <NUM> as necessary at steps <NUM> and/or <NUM>. No action is required at <NUM> as the outlet valve is already open in the subsequent iterations of the loop through steps <NUM> to <NUM>. Each step <NUM> sees the controller <NUM> loop back through further pressure and temperature checks all the while the user has not ended the shower mode.

A person skilled in the art will appreciate that the above embodiments may be varied in many different respects without departing from the scope of the present invention that is defined by the appended claims.

In the above embodiment, a hay steamer <NUM> is described. However, the hay steamer <NUM> is not limited to steaming only hay. For example, the hay steamer <NUM> may be used for steaming any type of animal fodder such as straw, silage and haylage. The hay steamer <NUM> may also be used for growing plants, fruits and vegetables. For example, the hay steamer <NUM> may be used to pasteurise straw or other substrate when growing mushrooms. The hay steamer <NUM> may be used to steam silage in bales or in loose form.

The hay steamer <NUM> resembles a wheeled-trunk, and has a size suitable for containing a standard-sized hay bale <NUM>. The hay steamer <NUM> can also be sized to hold half-sized and other sized bales, or loose hay.

While the lower part <NUM> and the upper part <NUM> are described above as being joined by hinges <NUM>, other arrangements are possible. For example, the lower part <NUM> and the upper part <NUM> need not be joined at all, such that the upper part <NUM> may be lifted from the lower part <NUM> when the hay steamer <NUM> is to be loaded and unloaded. In the above embodiment, the seal <NUM> is provided on the upper part <NUM>, but the seal <NUM> may be provided on the lower part <NUM> instead. In alternative arrangements, the seal <NUM> is formed as a ridge of material so as to be integral to either the lower part <NUM> or the upper part <NUM>. Also, rollers may be used in the place of wheels <NUM>, or the wheels <NUM> may be omitted altogether. The capacity of the water tank <NUM> may also be varied.

The boiler <NUM> is described as having three outlets to connect to the three steam vents <NUM>. However, a single outlet to the boiler <NUM> may be provided that feeds one or more manifolds that split the common steam flow from the boiler <NUM> into separate steam paths for the three steam vents <NUM>. The valves of the valve set <NUM> would be placed downstream of the manifolds to control steam delivery to each of the steam vents <NUM>.

The temperature, pressure and time bands described above are examples, and may be varied, as may the number of phases performed in a steaming process. The number of steam vents <NUM> may be varied, as too may the firing sequence of high-pressure steam jets <NUM> from the steam vents <NUM>.

Claim 1:
An apparatus for steaming animal fodder, optionally a hay steamer, comprising:
a body defining a chamber in which animal fodder may be placed, the body comprising an upper part and a lower part configured to be placed together to form the chamber, the lower part including a floor on which the animal fodder is supported;
an aperture provided in the floor of the lower part;
a conduit configured to carry steam to the aperture thereby allowing steam to pass into the chamber; characterised in that it further comprises
a controller arranged to control passage of steam to and through the aperture in at least one combined cycle comprising:
a low-pressure phase in which the controller allows steam to pass to and through the aperture into the chamber at a relatively low pressure;
a high-pressure phase in which the controller allows steam to pass to and through the aperture into the chamber at a relatively high pressure; and
such that each combined cycle of the least one combined cycle includes the low-pressure phase followed by the high-pressure phase.