Untitled record

© Patent holder (s):

Joxa BV in Weerselo.

Patent granted:

26.06.2015

Inventor (s):

Bart Wolbers in Weerselo.

© Patent issued:

01.07.2015 © Authorized representative:

ir. AAG Land et al. in The Hague.

© Device and system for drying manure.

The invention relates to an apparatus for drying manure, comprising:

- a housing;

- supply means for supplying manure to the housing;

drainage means for discharging dried manure from the housing, and

- drying agents for drying manure present in the housing at a certain temperature.

The invention further relates to a manure drying system comprising such a device.

LC 2012021

This patent has been granted regardless of the enclosed result of the prior art research and written opinion. The patent deviates from the documents originally filed. All submitted documents can be viewed at the Netherlands Patent Office.

DEVICE AND SYSTEM FOR DRYING MANURE

The invention relates to an apparatus for drying manure.

An apparatus for drying manure is known per se. Such a manure drying device can be used on a large scale and separates the water from the manure, for example by supplying drying air to the manure. The manure dried with this device has a dry matter content of about 30% - 35%.

It is an object of the invention to provide an alternative and / or improved manure drying device. In particular, it is an object of the invention to provide a manure drying device that can be used on a small scale and can be set up, for example, at a farm. Alternatively or additionally, it is an object of the invention to provide a manure drying device with which the manure can be dried to a dry matter content of about 80% - 95%, in particular up to about 85% - 90%.

To this end, the invention relates to an apparatus for drying manure, comprising:

- a housing;

- supply means for supplying manure to the housing;

- discharge means for discharging dried manure from the housing;

- drying means for drying manure present in the housing at a certain temperature, and moving means arranged in the housing for moving, in particular stirring, manure.

By supplying manure to the housing, allowing the manure to remain in the housing for a certain period of time, and drying the manure in the housing at a certain temperature during the residence time, the manure with the device according to the invention can be efficiently and / or well dried, in particular to a dry matter content of about 85% - 95%. The device according to the invention can be made with any desired size, in particular on a relatively small scale, so that the device can be set up at a farm or the like.

By moving, in particular stirring, the manure, the vapor can easily escape from the manure and drying of the manure will take place more efficiently and / or faster. The moving means are preferably adapted to only move the manure and not to move it in, for example, the direction of transport of the conveyor belt, since moving the manure can lead to a too short or long residence time of the manure in the housing.

The moving means may comprise, for example, at least one carrying rod extending transversely of a conveyor belt, with a number of stirring bars attached thereto spread over the length of the carrying rod. The carrying rod with stirring bars is preferably rotatable in a direction opposite to the conveying direction of the conveyor belt.

The device according to the invention is suitable for drying any manure, in particular, but not exclusively cattle manure, pig manure, rabbit manure, poultry manure and horse manure.

The residence time of the manure in the housing is preferably at least 40 minutes, more preferably at least 50 minutes, even more preferably at least 60 minutes, even more preferably at least 120 minutes. It has been found by the applicant that by drying the manure for this minimum time, the manure can be dried to the desired dry matter content. If a different dry matter content of the manure is desired, for instance higher or lower than about 90%, the residence time of the manure in the housing and, in particular, the drying time of the manure can be adjusted accordingly.

The determined temperature is preferably at least about 70 ° C, in particular between 70 ° C - 100 ° C. It has been found by the applicant that the manure can be dried at such a minimum temperature to the desired dry matter content, because moisture present in the manure can evaporate at such a minimum temperature. Moreover, such a minimum temperature is sufficiently high to separate ammonia and / or other gases from the manure. If a different dry matter content of the manure is desired, for example higher or lower than about 85 95%, the temperature at which the manure is dried can be adjusted accordingly.

In an embodiment of the device according to the invention, the drying means comprise a heat exchanger arranged in the housing, which heat exchanger is arranged for transferring heat to the manure.

With a heat exchanger, the drying of the manure can take place well and / or efficiently due to a good heat transfer. The heat exchanger can be in direct as well as indirect contact with the manure during drying.

In another embodiment of the device according to the invention, the heat exchanger comprises a substantially horizontally arranged element with a hollow space, which element comprises a supply for supplying a warm medium to the hollow space and a discharge for discharging from the hollow space of the medium after delivery of heat to the manure.

The manure can be applied directly or indirectly to the horizontally arranged element, whereby heat transfer takes place between the warm medium in the hollow space of the element and the manure for heating and thereby drying the manure. After heat has been released, the medium cooled thereby can be discharged from the hollow space via the outlet, whereby fresh, warm medium can be supplied to the hollow space via the inlet. For example, the medium can be liquid or gaseous. In particular, the medium can be supplied as a gas to the cavity, the gas in the element being able to condense by heat release and thereby efficiently transfer heat to the manure.

The device preferably comprises vapor discharge means for discharging vapor evaporated from the manure, which vapor discharge means are connected in a flow-through manner to the supply of the element for supplying the vapor discharged from the housing to the cavity.

An advantage of this preferred embodiment of the invention is that the vapor from the manure, which vapor has a relatively high temperature, for example about 100 ° C, can be used as the warm medium which is supplied to the cavity of the element. By reusing the heat removed from the manure in this way, the device has a relatively high efficiency.

Practically the device comprises a compressor arranged in flow direction between the vapor discharge means and the supply of the element for compressing vapor discharged from the housing to a predetermined pressure.

By compressing the vapor, its temperature is raised before the vapor is supplied to the cavity, so that the vapor can heat the manure better. For example, the temperature of the vapor from the manure, which may have a temperature of about 100 ° C on discharge, can be increased by compression to about 115 ° C at a pressure of about 3 bar. The energy to be supplied to the device is hereby limited to the energy remaining for compression, whereby the further energy required for drying the manure is obtained from the discharged vapor. It is noted that additional energy must be supplied when the device is started. It is further noted that the vapor can be compressed to any desired and suitable pressure and thus temperature.

In yet another embodiment of the device according to the invention, the device comprises a separator arranged in flow direction between the vapor discharge means and the supply of the element for separating vapor discharged from the housing into water vapor and other gases, for example ammonia and / or urea.

By separating the water vapor from other gases, the clean water vapor can be properly supplied to the heat exchanger, so that the heat exchanger is not attacked or contaminated by any other gases. With a surplus of water vapor, it is also possible to discharge the clean water vapor. The separator can, for example, be a cracking tower.

The other gases separated from the water vapor, such as ammonia and urea, can optionally be used as fuel. To this end, in one embodiment of the invention the device comprises an electricity generating device connected to the separator for generating electricity based on the other gases as fuel. The electricity generating device can for instance comprise an internal combustion engine with a generator connected to it or a fuel cell. The fuel cell can for instance be a so-called solid oxide fuel cell (SOFC).

In an embodiment of the device according to the invention, the heat exchanger comprises a cushion plate. Such a cushion plate is known per se and is a hollow panel comprising two plate-shaped sides which are connected to each other in a circumferential manner in a gas-tight manner and spread over their surface in a determined pattern. Such a cushion plate offers a sturdy heat exchanger to which the warm medium can optionally be supplied under pressure to heat the manure.

In yet another embodiment of the device according to the invention, the device comprises a conveyor belt arranged in the housing for transporting the manure from the supply means to the discharge means.

By choosing a conveyor belt with a certain size, in particular with a certain transport length, and / or by choosing a suitable transport speed of the conveyor belt, the residence time of the manure in the housing can be easily adjusted. The manure is dried during transport thereof.

In practice, the conveyor belt is arranged at least partly around the heat exchanger for transporting manure along the heat exchanger. The manure is heated during transport by heat transfer via the heat exchanger and thereby dried.

In yet another embodiment of the device according to the invention, the device comprises moving means arranged in the housing for moving, in particular stirring, manure.

The invention further relates to a system for drying manure, comprising:

- a manure drying device according to any one of claims 1 to 10, comprising:

- a housing;

- supply means for supplying manure to the housing;

- discharge means for discharging dried manure from the housing;

desiccants for drying manure present in the housing, and

- moving means arranged in the housing for moving, in particular stirring, manure and at least one of:

- a press arranged in the direction of transport of the manure downstream of the discharge means and coupled thereto for pressing dried manure;

- a storage means disposed in the direction of transport of the manure downstream of the discharge means, and optionally downstream of the press, for storing, if necessary, dried manure; and

- viewed in the direction of transport of the manure downstream of the discharge means, and possibly downstream of the press, a combustion boiler arranged for burning, optionally pressed, dried manure, for generating heat.

The advantages of the device according to the invention have been further explained above.

The press has the advantage that it allows the dried manure to be pressed into solid bodies, such as granules, pellets or briquettes. The solid bodies thus formed can easily be further processed and / or marketed. Optionally, the solids are cooled after pressing to prevent fusion thereof. Cooling can take place, for example, by exposing the solids to cold air, for example outside air.

The storage means serve for at least temporarily storing the dried, optionally pressed, manure, until further processing or marketing of the manure.

With the help of the combustion boiler, the dried manure or possibly another fuel can be burned to generate heat. For example, the heat can be used to heat buildings in the vicinity of the system or to heat the medium supplied to the heat exchanger. Heating the medium can be particularly advantageous when starting up the device according to the invention, when a warm vapor from the gas is still present.

The invention further relates to the use of a manure drying device according to any one of claims 1 to 10 or a manure drying system according to claim 11, comprising the steps of:

(a) supplying manure to the housing;

(b) allowing the manure to remain in the housing for a specified period of time;

(c) drying the manure present in the housing at a certain temperature, and (d) discharging dried manure from the housing after the period of time has elapsed.

The advantages of the device and / or system according to the invention and thus of the use thereof have been further explained above.

As already indicated above, it is advantageous if the determined time is at least 40 minutes, preferably at least 50 minutes, more preferably at least 60 minutes, even more preferably at least 120 minutes.

As already indicated above, it is advantageous if the temperature is at least 70 ° C, and preferably between 70 ° C - 100 ° C.

The invention will be explained in more detail with reference to figures shown in a drawing, in which:

Figure 1 schematically represents a system according to the invention with a device according to the invention; and

Figures 2A-2C show a conveyor belt with stirring means of figure 1 in more detail, figure 2A being a top view, figure 2B a side view and figure 2C a front view.

Figure 1 shows a system 1 for drying manure. The system 1 comprises a device 2 with a housing 3. On one side of the housing 3 a feed hopper 4 is connected for supplying manure to the housing 3. In the feed funnel 4 a auger 5 is arranged for preferably dosing on a conveying manure substantially horizontally disposed. The conveyor belt 6 moves the manure substantially horizontally through the housing 3 to an opposite, second side of the housing 3. The conveyor belt 6 extends around a heat exchanger 7, so that heat transfer between the heat exchanger 7 and the manure arranged on the conveyor belt 6 can take place, so that the manure during its transport through the housing 3 is heated and thereby dried. The heat exchanger 7 can be a so-called cushion plate, which cushion plate comprises a hollow space. The cushion plate comprises an inlet 8 and outlet 9 connecting to the hollow space. Via the inlet 8, a warm medium can be supplied to the heat exchanger 7 and via the medium cooled in the heat exchanger 7 can be discharged outlet 9. The supply 8 connects to a discharge end of the conveyor belt 6 and the discharge 9 connects to a supply end of the conveyor belt 6, or near the supply funnel 4, so that the fresh medium with the highest temperature can heat the driest manure and so that the net supplied and therefore relatively wet manure is heated by the partly cooled medium. Stirring means 18 are arranged near a discharge end of the conveyor belt 6 for stirring, but not moving the manure in or against the transport direction of the conveyor belt 6. The liquid contained in the manure can evaporate well by stirring and thereby stirring the manure. Because the manure is not moved, the residence time of the manure in the housing 3 is determined by the length and transport speed of the conveyor belt 6. The stirring means 18 can alternatively also be arranged along the entire length of the conveyor belt 6, as shown in figure 2A.

The manure dried in the housing 3 is then discharged on the second side of the housing 3 to a chunk press 10 for pressing the dried manure. Using a second conveyor belt 11, the compressed manure is passed through a cooling space 12 for cooling the pressed manure. The pressed, cooled manure is then moved obliquely upward with the aid of a mortar 13 and fed to a silo 14 for storing the pressed and cooled manure. The manure stored in the silo 14 can be used for firing a combustion boiler 15 to provide hot water with a maximum temperature of, for example, about 95 ° C. This hot water can be used, for example, for heating a building as well as as a warm medium for the heat exchanger 7, in particular during the start-up of the system 1. To this end, the boiler 15 is connected to the heat exchanger 7 by means of a medium flow through a two-way valve 16. . A conveyor 17 is provided for transporting manure from the silo 14 to the boiler 15. The manure stored in the silo 14 can optionally also be sold as fuel.

The device 2 further comprises a number of cracking towers 20. Vapor from the manure is supplied to the cracking towers 20 for separating ammonia and / or urea and any other gases from water vapor. The ammonia and / or urea can be discharged or used to generate electricity in an electricity generating device (not shown). The water vapor is compressed in a compressor 21. This increases the pressure and thereby the temperature of the water vapor, for example from about 100 ° C to about 115 ° C. The water vapor can then be supplied to the heat exchanger 7 via the two-way valve 16. In the heat exchanger 7, the water vapor gives off heat to the manure and condenses into water.

As has become clear from the above, it can be set with the aid of the two-way valve 16 whether water vapor originating from the housing 3 and compressor 21 or water heated by the boiler 15 is supplied to the heat exchanger 7. In practice, during the start-up of the system 1, water from the boiler 15 is supplied to the heat exchanger 7 and during operation, if sufficient water vapor is obtained from the manure, the water vapor is supplied to the heat exchanger 7. The water discharged from the heat exchanger 7 via the discharge 9 is discharged via a two-way valve 22 to, for example, a sewer or supplied to the boiler 15.

Figures 2A-2C show the conveyor belt 6 with the heat exchanger 7 arranged therein in more detail. This shows that the conveyor belt 6 with an undersurface thereof rests against an upper side of the heat exchanger 7, as a result of which there can be an efficient and / or good heat transfer for drying manure present on the conveyor belt 6. Stirring means 18 are arranged above the conveyor belt 6 for stirring or stirring the manure. The stirring means 18 comprise a number of stirring bars 30, each with a widened end 31, which stirring bars 30 are attached to a number of carrying bars 32 extending transversely over the conveyor belt 6. As can be seen from Figure 3B, the carrying rods 32 and thereby the stirring rods 30 rotate in a direction 34 opposite to the conveying direction of the conveyor belt 6, so that the manure cannot be moved at least in the conveying direction. Since the carrying rods and stirring rods 30 rotate slowly, there will essentially also be no question of moving the manure against the direction of transport of the conveyor belt 6. The liquid present in the manure can evaporate well by stirring and thereby stirring the manure over almost the entire transport length of the conveyor belt 6. Because the manure is not moved, the residence time of the manure in the housing 3 is determined by the length and transport speed of the conveyor belt 6. Figures 2A and 2B further show that the conveyor belt 6 comprises a drive drum 35 and a turning drum 36.

It is noted that the invention is not limited to the embodiments shown, but also extends to variants within the scope of the appended claims.

For example, instead of two-way valves, there can also be three-way valves.