BACKGROUND OF THE INVENTION:

Field of the invention

The invention relates to a device for processing wet manure, comprising: feed means for bringing in the wet manure, and

- cleansing means for cleaning the wet manure, and

discharge means for taking away the impurities remaining behind after cleaning, which cleansing means comprise an evaporator for the evaporation of the water present in the wet manure, which evaporator:

comprises a body to be heated for the evaporation of water, and

- heating means for heating the body and keeping it at a temperature over 100 °C, a discharge opening for water vapour,

a feed line for wet manure, which feed line is part of the feed means,

nozzles that are connected over the length of the feed line to the feed line and that are directed toward the body, and

- a discharge line for impurities, which discharge line is part of the discharge means.

Organic fertilizer, such as pig and cow manure, contains about 95% liquid and approximately 5% solids. Wet manure is understood to mean the liquid that forms the remaining portion of the manure after the solids have been removed, for example by filtering. This wet manure is polluted water and contains too many impurities to be allowed to be discharged. This liquid must first be purified before it may be discharged.

Prior art

Such a device is known from DE4418673A1. The body of the known device is formed by a drum which is heated. The liquid to be purified is sprayed on the lateral surface of the cylinder, whereby the liquid evaporates and the solid particles are scraped from the drum. The purification of wet manure with the known device such that it is allowed to discharge it with the aid of the known device is an expensive process. So, it is cheaper to take away the manure with tank lorries and transport it to remote areas where there is a shortage of manure. As a result, discharging manure is relatively expensive.

Summary of the invention

An objective of the invention is to provide a device for the purification of wet manure of the type described in the preamble, whereby the liquid remaining after purification is sufficiently pure to be discharged and the purification is more efficient and therefore requires less energy than with the known device. To this end, the device according to the invention is characterized in that the body is a double-walled drum, provided with an outer wall and an inner wall, in which there is liquid between the walls, and whereby the feed line is located within the inner wall of the drum and extends in a longitudinal direction from the drum. Preferably, the body is held at a temperature of more than 200 °C. By aiming the nozzles at the body, at least part of the water droplets in the streams of water sprayed toward the body will evaporate before they reach the surface of the body. In this manner, large quantities of water can be evaporated efficiently per time unit. The evaporated water is sufficiently pure to discharge into the environment.

It is noted that a double-walled drum for heating liquid which contains solid particles is known from GB1312414A. However, in that device the liquid is not sprayed from a central line onto the inner wall of the drum.

Preferably, the device also comprises suction means for discharging the water vapour.

Water vapour contains a great deal of energy. In order to be able to recover this energy, an embodiment of the device according to the invention is characterized in that this also comprises a condensation device for condensing the water vapour. Preferably, this condensation device is part of a heat exchanger in which the heat released during condensation is used for heating air or water in a heating system.

Preferably, the body is filled with oil, for example thermal oil. Such a heated body has a great heat capacity, and therefore does not cool down quickly.

The drum is preferably rotatably mounted in a stationary outer drum in order to retain the heat better and ensure that less heat is lost to the environment. Preferably, the drum is positioned at an angle, so that the rising water vapour can leave the drum at its uppermost open end and the solid particles that remain after evaporation can leave the drum through its lowest end due to gravity. Brief description of the drawings

Below, the invention will be explained in more detail on the basis of a drawing in which an embodiment of the device according to the invention is shown. Figure 1 is a schematic diagram of an embodiment of the device according to the invention.

Detailed description of the drawings

In Figure 1, an embodiment of the device according to the invention for processing wet manure is shown in a schematic diagram. The device 1 is provided with feed means for bringing in the wet manure 2, as well as cleansing means for cleaning the wet manure, and discharge means for discharging the impurities that remain after the cleaning. These cleansing means comprise an evaporator 3 for the evaporation of the water present in the wet manure. The device also has suction means 5 for the water vapour 7 to be extracted and brought to a heat exchanger 9. The water vapour is condensed in this heat exchanger. The water 10 coming out of the heat exchanger can then be discharged into the surface water. A liquid 12 is warmed up with the heat coming from the condensation process in the heat exchanger that can be used for heating purposes.

The evaporator 3 has a body that can be heated that is in the form of a double-walled drum 13 for the evaporation of water. The double-walled drum 13 is provided with an outer wall 13 A and an inner wall 13B, with an enclosed cavity between in which thermal oil 14 is found. In addition, the evaporator has heating means 15 for heating the drum and keeping it at a temperature over 180 °C. These heating means 15 are formed by a number of burners which are aimed at the outer wall 13A of the drum 13 and heat this outer wall to about 600 °C. The drum 13 is positioned at an angle and is provided with a discharge opening 19 at the top end for water vapour and a feed line 17 for wet manure. This feed line is located inside the inner wall 13B of the drum and extends in a longitudinal direction from the drum. In addition, the evaporator has nozzles 23 which are connected to the feed line 17 and directed at the inner wall 13B of the drum.

The drum is rotatably mounted in a stationary outer drum 11 by means of bearings 21. The wall of this outer drum 11 is preferably well insulated to keep the heat inside the drum. After the oil 14 in the drum wall has reached a temperature above a certain set value of, for example, 250 °C, the burners are turned off. After the temperature of the oil 14 during the evaporation of water has decreased at a further adjustable value of, for example, 180 °C, the burners are switched on again until the oil 14 is heated up again to 250 °C.

During operation, the wet manure 2 is sprayed via the nozzles 23 in the direction of the heated inner wall 13B of the rotating drum 13. The water in the droplets of wet manure sprayed toward the drum will evaporate before the droplets reach the heated surface of the drum. In this manner, large quantities of water can be evaporated efficiently from the wet manure per time unit. The solid impurities 4 remaining after evaporation of the water are discharged via a discharge line 18 connected to the lowest end of the drum 13.

Although in the above the invention is explained on the basis of the drawing, it should be noted that the invention is in no way limited to the embodiment shown in the drawing. The invention also extends to all embodiments deviating from the embodiment shown in the drawing within the context defined by the claims.