DE102007063750B4 - Device and method for hop drying - Google Patents

Abstract

The invention relates to a device for hop drying, wherein the device comprises an air inlet, a temperature and humidity sensor (6a) for determining the temperature and humidity of air sucked through the air inlet, a heating furnace (4) and a fan (5) and in the upper region an air outlet with a temperature and humidity sensor (6b). According to the invention it is proposed that the device has an additional temperature sensor after the heating furnace (4), an oil meter, preferably for indirect wind speed measurement within the device, and a control unit for controlling the volume flow of the air within the device. Furthermore, a method for hop drying in a Darre (1) is described, which has in the lower area an air inlet, a fan (5) for introducing drying air into the kiln (1) and a heating furnace (4) for heating the drying air, wherein determined oil consumption, taking into account the difference between the temperature of the sucked drying air and the temperature of the heating furnace (4) exiting drying air, a defined volume flow of the heating furnace (4) heated drying air is assigned, and wherein from the volume flow, the air velocity of the drying air within the Darre (1) is calculated.

Description

The present invention relates to an apparatus and method for hop drying.

When drying the hop in a kiln, an optimal process under reproducible conditions is particularly important because on the one hand no drying capacity should be given away but on the other hand it must be ensured that there is never too much wet hops in the kiln. This would mean that the installed fan power is no longer sufficient to maintain the air flow, and there is a risk that the hops fermented on the uppermost layer by condensation of water.

Various devices and methods for hop drying are known in the prior art. In the DE 201 03 191 U1 For example, a device for conditioning hops for single or multi-chamber systems is known. A conditioning device is provided, wherein a hygrostat measures the moisture content of the supplied mixed air and controls the mixing ratio between circulating air and fresh air by controlling the circulating air and fresh air quantity sucked in by the conditioning device and thus the humidity of the conditioning air.

The DE 199 05 426 C2 describes a method and a device for the continuous drying of crops harvested in the agricultural harvesting operation, in particular for the continuous drying of hops. According to the invention, the bulk material to be dried is applied to a conveying means drivable with an adjustable conveying speed. With this funding, the bulk material is transported through a microwave chamber, wherein the bulk material is dried during the passage through the microwave chamber by means of a microwave radiation generated there by at least one magnetron to a required bulk moisture and then removed from the microwave chamber.

Another method and apparatus for drying green hops is in the DE 21 22 235 A1 disclosed. Here, the core of the invention lies in the fact that for the drying air with a temperature of about 95 ° C and a speed of about 0.8 m / s is supplied.

The object of the invention is to perform the hop drying faster and more accurate and thus to reduce costs.

The object is achieved by a device according to claim 1 and a method according to claim 8. Further developments of the invention are specified in the subclaims.

Further features and advantages of the invention will become apparent from the description of embodiments with reference to the accompanying drawings. From the figures show:

1 a schematic front view of a Hopfendarre;

2 a schematic view of a compensation chamber for dried hops;

3 a schematic view of a mixing device;

4 a schematic view of the mixing device in the setting "drying with Darrluft";

5 a schematic view of the mixing device in the setting "humidifying and heating with dry Darrluft and basic air";

6 a schematic view of the mixing device in the setting "humidifying and cooling with basic air";

7 a schematic view of the mixing device in the setting "humidifying and cooling with circulating air or alternative air";

8th a Mollier-hx diagram with the axes temperature and relative humidity with marked operating ranges.

The following is with reference to the 1 to 3 A first embodiment of the device of the present invention is described.

In 1 is a hopscotch 1 shown. It has two tilts arranged one above the other 2 , a slipcase underneath 3 , a stove 4 , a fan 5 , an air inlet with a temperature and humidity sensor 6a in the lower area of the Darre 1 and an air outlet with a temperature and humidity sensor 6b in the upper area of the Darre 1 on.

In the Darre 1 is also a (not shown) optional temperature sensor in the fan for measuring the intake air, if additional heat is fed (waste heat from the generator, woodchip heating, etc.), a (not shown) temperature sensor in the channel after the heater 4 , a digital oil meter for indirect wind speed measurement or to calculate the transported away Amount of water, an air volume flow control unit (not shown) (eg, frequency converter, throttle) (not shown), and a software implemented digital controller (not shown).

2 shows a compensation chamber 10 for the one in the Darre 1 pre-dried hops. The compensation chamber 10 is the Darre 1 downstream. It has a suction channel 11 for Darrluft or alternative air, an absolute moisture meter 12 for the hop moisture, a humidity and temperature sensor 13 and a mixing device 20 on.

3 shows schematically the structure of the mixing device 20 , She has a lid 21 in the form of an inspection cover or a service door, an air duct 22 for the supply of optional air, but at least one alternative dry hot air source or dry Darrluft, further a Ausgleichskammerzuluftkanal with preferably a temperature and humidity sensor 23a , a temperature and humidity sensor (not shown) for the exhaust air from the compensation chamber 10 , a first suction port 24 for base air which is passed through the cooling and moistening device (pad), a second suction port 25 for basic air without cooling and moistening device (pad) and the feed of the air duct 22 in the Klimabox here again with the flaps 27a , b, c, d a redistribution of air flow proportionate with and without cooling and moistening device (pad) 28 can be adjusted. In this case, the air data from the drying process can be used. Furthermore, the mixing device 20 a fan 26 , several flaps 27a , b, c, d with electric damper actuators for controlling the volume flows, a cooling and moistening device (pad) 28 with pump station and automatic fresh water replenishment, in the form of adiabatic evaporative cooling and a digital controller (not shown) with implemented software.

The operation of the hop-drying device is as follows: The hop is tilting 2 the Darre 1 pre-dried, with the tilting 2 move the hops down by tilting the soil down. When the desired temperature and humidity are reached, the topmost tipper moves 2 The hops first in the farther down tipping 2 , This transports the hops into the slipcase 3 Finally, the hops to further drying, or to compensate for the humidity and temperature in the leaves and the spindles of the hop in the compensation chamber 10 transported.

From the ones in the Darre 1 and the compensation chamber 10 measured temperature and humidity values, the optimum mixing ratio r (g / kg), the absolute humidity d (g / m ³ ) and the enthalpy E (kJ / kg) of the compensation chamber 10 calculated air to be supplied and the mixing device 20 regulated accordingly.

It is a central control unit 100 provided, which is designed so that the entire system can be controlled with the measured data of the aforementioned temperature and humidity sensors to achieve optimum operation. In this way, the hops can be dried fully automatically to an exact temperature and humidity value.

Likewise, an averaging of the oil consumption of the stove takes place 4 in the Darre 1 in a certain period of time. This oil consumption is assigned a defined volume flow of the heated air from the temperature difference between the intake and exhaust air from the furnace. From this, the air velocity of the drying air in the kiln can be calculated. These computation steps are repeated constantly, so that continuous values are generated which can be fed to the control loop. By comparing intake and exhaust air, it is calculated how much water the air removes during the drying process.

The aim is to optimally adjust the air velocity during the drying process to achieve the highest drying performance. The optimum air velocity when drying hops is between 0.3 and 0.4 m / s. Since hops are a capillary-porous and hygroscopic material, special consideration has to be given to a division of the drying into several drying phases.

Since the drying of the hop is very inhomogeneous due to the different moisture content of the blade and spindle, the hops must be even after drying. This happens in the compensation chamber 10 with a ventilation system. Depending on the residual moisture and temperature, it is necessary to offer hops a suitable composition of the injected air, with the aim of bringing the hops to a given total moisture content.

The hops are dried in a controlled manner so that the hops can be brought to an optimum moisture content and therefore optimal weight, so that a constant residual moisture level in the compensation chamber can be achieved 10 is reached. The hops must also be dry enough, since rewetting is easier than nachzutrocknen hops with too much spindle water content in the chamber, as this very high temperatures are needed.

In addition, the mixing device offers 20 the possibility to provide exactly the required composition of the air. The mixing device 20 Adiabatic evaporative cooling is used for air humidification, since the resulting cooling causes the process of homogenization in the compensation chamber 10 can be slowed down if necessary. Since the pure cooling device operation is needed only in exceptional cases, offers the mixing device 20 a mixed air system which allows the volume of air through the cooling and moistening device (pad) 28 and to mix the quantities of air supplied directly to the blower. In this way all operating conditions during conditioning can be covered.

The automatic drying and drying technology divides drying into four areas:

1st start-up phase

• - The start-up phase is activated immediately after filling and prepares the hops for drying
• - warming up the hops
• - The drying rate increases

2. External drying

• - The capacity of liquid evaporation at the surface is fully utilized
• - Liquid Nachförderung through the capillaries of the hop
• - the maximum drying speed has been reached

3. Inner drying

• - The capacity of the liquid evaporation is equal to the capacity of the capillaries
• - Displacement of the drying mirror inside
• - The drying rate drops

4. Hygroscopic drying

• - takes place in all places of the estate
• - The drying rate is minimal

Since for each phase of drying other requirements are placed on the drying parameters, such. As the drying temperature or the air velocity, now controls the control unit 100 the procedure of the procedure. During or after refilling the Darre 1 with fresh hops, the process starts either manually or automatically depending on the controller setting. From then on, the control unit follows 100 the drying process. In this way, optimal water removal and thus optimum drying efficiency and optimal energy use is achieved.

As the drying of the hop progresses; the relative exhaust air humidity slowly decreases and the exhaust air temperature increases as well, as the dehydration of the hoppers adiabatically runs along the isenthalps in the hx-diagram (see 8th ). At the same time, the absolute exhaust air humidity as well as the mixing ratio change as these parameters are calculated from the exhaust air humidity and temperature. The control unit 100 therefore recognizes at these parameters in which drying stage the hops are currently.

Since there are also big differences between the hop varieties to be dried, variety-specific programs can now be entered and also saved. Thus, particular attention can be paid to vintage-specific characteristics of hop varieties and the farmer now has complete control over the drying process.

The control unit 100 recognizes the phases on the course of the water delivery. Drying-relevant parameters and system limits can now be entered for all phases. The control circuit adjusts the air flow of the Darre 1 on, so that sets the desired air speed in the hordes.

The calculated parameters, such as the absolute humidity and their difference between input and output in the kiln 1 , as well as the volume flow make it possible to indicate the effective water drainage and to integrate it into the control loop. On the one hand, this display serves to control the drying process and, on the other hand, offers the possibility of checking the efficiency of the individual phases. The calculated water drainage can in turn be fed to an adaptive control loop that automatically adjusts the optimum wind speed.

Since the air output now follows the degree of drying and the air does not leave the drying process in a partially unsaturated state, the heating energy consumption is significantly reduced. Likewise, the effect of a more uniform drying in the area, since the air can also be better distributed due to the optimized speed.

In the drying process is now repeatedly tipped and top fresh hops refilled. The hop in the slipcase is on reaching a certain residual moisture from the kiln 1 taken. The hops to be removed can be determined with the aid of the absolute moisture meter 12 be judged on the water content. Likewise, this absolute moisture meter 12 stuck in the Darre 1 remain built-in to constantly get values about the water content of the hops. The absolute moisture meter 12 Measures the hop moisture with the help of signal transit times. Location of this absolute moisture meter 12 is the Darre and the conditioning chamber are emptied into the ready-dried slipcase.

• – Befeuchten und Kühlen
• – Befeuchten und Erwärmen
• – Trocknen

The operating states of the mixing device 20 can be related to the 4 to 8th divide into the following areas:

• - moistening and cooling
• - moisten and warm
• - Dry

4 shows the operating state "drying with Darrluft" or "drying with alternative dry hot air source" and base air of the mixing device 20 , Air from the air duct 22 and the second suction port is mixed and by the fan 26 in the direction of the conditioning chamber through the conditioning channel 23 directed.

5 shows the operating state "humidifying and heating with dry kiln air or alternative dry hot air source and base air" of the mixing device 20 , Air is passing through the first intake port 24 sucked in by the cooling and moistening device (pad) 28 passed, then mixes with the air from the air duct 22 and finally flows through the conditioning channel 23 ,

6 shows the operating state "humidifying and cooling with basic air" of the mixing device 20 , Air is passing through the first intake port 24 sucked in by the cooling and moistening device (pad) 28 passed, then mixes with the air from the second suction port 25 and finally flows through the conditioning channel 23 ,

7 shows the operating state "humidifying and cooling with circulating air or alternative air" of the mixing device 20 , The air passes through the air duct 22 sucked. Part of the air flow is through the cooling and moistening device (pad) 28 and finally flows through the conditioning channel 23 , the other part of the airflow flows directly there.

The important thing is that at an input of the mixing device 20 warm air is available. This can be diverted from the dry Darrluft or fed by its own heat source.

Since this system requires thermodynamic calculations to set the individual flaps, now takes over the control unit 100 the control of the mixing device 20 , The control unit 100 decides on the constellations of the flaps 27a , b, c, d at the respective operating conditions and also mixes the requested humidity and temperature. Even changes in the intake air during the process are detected and the controller automatically switches to the appropriate program if a system limit is exceeded.

The sorption isotherms of different hop varieties are stored in the controller, so that a selection of the parameters of temperature and humidity of the air to the desired predetermined hop moisture is possible. To enrich the hop. With water or even the final drying, the absolute humidity of the supply air as well as the exhaust air is determined and from this the difference is formed. There is also a subdivision of the homogenization process in two phases. Since the hops as described in the chamber should be brought to a target moisture and not during drying in the kiln 1 , water must be added to the hops.

The procedure divides the homogenization into two areas:

1st phase of water enrichment

• - The leaves of the umbels are using the mixing device 20 enriched with water with cool and moist air.
• - There is no balance between spindle and blade due to the low temperature.
• - An immediate removal of water from the spindle is deliberately prevented because the over-dried leaf would suck the water not from the environment, but from the spindle.
• - Monitoring the relative exhaust air humidity and temperature (distance to the sorption curve)
• - Protection against condensation by dew point determination

2nd equalization phase

• - Further enrichment of the hop with water, but at elevated temperature
• - Inner balance of hops of spindle and leaf water
• - Since the blade has already received water from the outside, has a lower suction effect on the spindle.
• - The hops are homogenized, but there is enough water and thus weight in the spindle.
• - A rewetting of the spindle would no longer be possible.
• - Monitoring the relative exhaust air humidity and temperature (distance to the sorption curve)
• - The water enrichment ends, if the desired final moisture content of the hop is reached and there is the further aeration with sorptionsneutraler air until complete compensation of the moisture between spindle and blade.

Due to the special behavior of the hop when balancing the humidity between spindle and blade, a program can also consist of several humidity and temperature specifications for certain phases. The farmer composes the program and the control unit 100 takes over the process control.

The technical possibilities of the mixing device 20 are the hx diagrams in 8th refer to. 8th shows by way of example the three different areas "humidifying and cooling", "humidifying and heating" and "drying with Darrluft" in Mollier-hx diagram. The temperature is above the water quantity. The line enclosing the three areas represents the possible environmental conditions with respect to temperature and relative humidity.

The method is not limited to the described three operating ranges. A finer division of the areas is conceivable.

In addition, a device for hop drying is proposed, which is a compensation chamber 10 in a Darre 1 dried hops is added and a mixing device 20 wherein the device is characterized in that in the mixing device 20 , based on measured data in the Darre 1 and the compensation chamber 10 , a gas can be supplied to the hop can be generated with a certain humidity and temperature.

It is advantageous if the compensation chamber 10 with the Darre 1 in which the hops are dried.

It is also advantageous if the Darre 1 and / or the compensation chamber 10 Have sensors for temperature and / or humidity measurement and an oil meter.

It is also advantageous if a regulation of the drying parameters in the kiln 1 takes place, such. As the regulation of the volume flow of air and / or the wind speed during drying and / or the temperature in the respective drying phases.

Advantageously, it may additionally or alternatively be provided that the parameters temperature and / or wind speed are regulated.

Furthermore, it is advantageous if the mixing device 20 an inlet, an outlet, a cooling and / or moistening device 28 and / or a heat source and / or a water source.

Also it can bring benefits when the mixing device 20 fold 27a , b, c, d, wherein the flaps 27a , b, c, d the volume flow of the gas in the mixing device 20 to lead.

Furthermore, the subject of the application is a method for hop drying in which the hop to be dried in a Hopfendarre 1 is pre-dried and then in a compensation chamber 10 is introduced. It is provided that in a mixing device 20 , based on measured data in the Darre 1 and the compensation chamber 10 , a gas with a certain humidity and temperature is generated, which is the hop in the compensation chamber 10 is supplied.

In this context, it may be advantageous if the drying proceeds in several phases.

Likewise, it brings advantages when the phases are run through start-up phase, external drying, internal drying, hygroscopic drying.

It is also advantageous if the in the compensation chamber 10 used air in a mixing device 20 reproducibly mixed and fed to the hops.

Furthermore, it is advantageous if as air for drying in the compensation chamber 10 dry Darrluft and / or an alternative heat source and / or base air is used.

In addition, it is considered advantageous if as air for humidifying and / or heating in the compensation chamber 10 dry Darrluft and / or an alternative heat source and / or base air is used.

Advantageously, it can be provided that as air for humidifying and / or cooling in the compensation chamber 10 Basic air is used.

Likewise, it is also advantageous if as air for humidifying and / or cooling in the compensation chamber 10 on optionally fed air through the air duct 22 can be accessed such. B. alternative types of air such as the exhaust air from the compensation chamber and / or warmer air under the roof of the Darre 1 ,

There are also advantages when the homogenization of hops takes place in phases.

It is advantageous if the phases of the water enrichment and the compensation phase are passed through during the homogenization.

After all, it can bring benefits when the mixing device 20 for the device for hop drying flaps 27a , b, c, d having the volume flow of the gas in the mixing device 20 to lead.

Claims (13)

Device for hop drying, the device having an air inlet with a temperature and humidity sensor ( 6a ) for determining the temperature and humidity of air entering via the air inlet, a heating furnace ( 4 ) and a fan ( 5 ) and in the upper area an air outlet with a temperature and humidity sensor ( 6b ), characterized in that the device has an additional temperature sensor within a channel after the heating furnace ( 4 ), an oil meter for indirect wind speed measurement and a control unit for controlling the volume flow of the air. Apparatus according to claim 1, characterized in that the device comprises a digital controller with implemented software. Device according to one or more of the preceding claims, characterized in that the device has an additional temperature sensor in the fan ( 5 ) is arranged. Device according to one or more of the preceding claims, characterized in that the oil meter is a digital oil meter. Device according to one or more of the preceding claims, characterized in that the control unit comprises a frequency converter or a throttle valve. Device according to one or more of the preceding claims, characterized in that the device has an absolute humidity meter ( 12 ) for determining the humidity of the hop within the device. Device according to one or more of the preceding claims, characterized in that the device is a Darre ( 1 ), a compensation chamber ( 10 ) and a mixing device ( 20 ), wherein the mixing device ( 20 ) Part of the compensation chamber ( 10 ). Method for drying hops in a kiln ( 1 ), which at the bottom of an air inlet, a fan ( 5 ) and a heating stove ( 4 ), characterized in that by means of a temperature and humidity sensor ( 6a ) the temperature and humidity of the air entering via the air inlet and with the help of another temperature sensor located inside a duct after the heating furnace ( 4 ), the temperature of the heating furnace ( 4 ) exiting air is determined that the oil consumption of the stove ( 4 ) is determined in a certain period of time and averaged over the time period that the average oil consumption taking into account the difference between the temperature of the intake air and the temperature of the furnace ( 4 ) leaving a defined volume flow in the heating furnace ( 4 ) is assigned to heated air, that from the volume flow the air velocity of the air within the kiln ( 1 ) and that the volume flow of the air is controlled during drying. Method according to the preceding claim, characterized in that the air velocity is continuously calculated, so that continuous values are produced, which are fed to a control loop. Method according to one or more of claims 8 and 9, characterized in that the air velocity is set during drying to a value between 0.3 and 0.4 m / s. Method according to one or more of claims 8 to 10, characterized in that the drying by means of a control unit ( 100 ) is controlled. Method according to one or more of claims 8 to 11, characterized in that the drying in the four areas start-up phase, external drying of the hop, internal drying of the hop and hygroscopic drying of the hop is divided. Method according to one or more of claims 11 and 12, characterized in that in the control unit ( 100 ) are entered and stored in them in order to be able to take into account the vintage-specific characteristics of hop varieties.

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