JPH0116557B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for efficiently treating human waste by drying and subsequent fermentation.

Biological treatment, including digestion, denitrification, and nitrification, is often adopted as a method for treating human waste, but this treatment requires a large area, so there are many restrictions due to location conditions, and the treatment is unstable. There were problems such as: Various methods have also been proposed for directly drying human waste, but none have been put into practical use due to high running costs and difficulty in processing exhaust gas.

The object of the present invention is to provide a processing method that can be processed with high efficiency by drying human waste and then fermenting it, without the problem of processing exhaust gas, and with low running costs.

Next, an example of the steps of the method of this invention will be explained with reference to the drawings. The dryer indicated by reference numeral 1 in the figure has a sealed housing 2, in which human waste is accommodated so as to maintain an appropriate liquid level. Further, inside the housing 2, a large number of discs 4 are installed at predetermined intervals on a water-damaged rotating shaft 3, with only a portion of the discs being located below the surface of the human waste. By rotating together with the rotary shaft 3 by the power of the motor 5, the disk 4 is pulled up above the liquid level with the human urine attached to its surface.
This increases the liquid area and improves the drying effect. (Stirring process) The code 6 is the housing 2.
A pipe for introducing human waste into the interior is shown.

In addition, at the same time as stirring the human waste, the housing 2
In order to dry the human waste inside, a compressor 7, a heater 8, a heat exchanger 9, a pressure reducing valve 10, a heat exchanger 11 are installed.
A heat pump consisting of a heater 12 and a heater 12 is provided. The gas inside the housing 2 is passed through the pipe 13
It is extracted through the heat exchangers 11, 9 and the heater 12, and then returned into the housing 2 through the pipe 14. (Human waste drying process) On the other hand, the heat medium is pressurized by the compressor 7, further heated by the heater 7, and then sent to the heat exchanger 9, where it exchanges heat with the exhaust gas, and then is depressurized. The pressure is reduced through valve 10. The heat medium whose temperature has been lowered by this pressure reduction enters the heat exchanger 11, where it is heated by heat exchange with the exhaust gas, and is transferred to the compressor 7.
will be returned to.

That is, the exhaust gas is cooled once while passing through the heat exchanger 11, heated by the heat exchanger 9, further heated by the heater 9, and then returned to the housing 2. Provides the heat necessary to dry human waste. Also, the heat exchanger 11
Condensed water generated when cooled inside pipe 1
5 and stored in a receiver 16.

On the other hand, concentrated human waste dried within the housing 2 is transferred to a fermentation tank 18 via a pipe 17.
The concentrated human waste taken out from the housing 2 is in the form of a concentrated cake (a cake-like form that does not have free-flowing properties).
It is composted by fermentation in the fermenter 18 under the action of thermophilic bacteria. (Fermentation process) The generated compost is taken out to the outside through the pipe 19, and some of it passes through the pipe 20 to the fermentation tank 1.
It will be returned within 8 days.

Furthermore, air is fed into the fermentation tank 18 through a pipe 21 in order to suppress abnormal temperature rise due to fermentation. And this air is the fermenter 18
After being heated inside, it is sent to heaters 8 and 12 through pipe 22. (Fermentation heat utilization process) Fermentation by thermophilic bacteria is generally carried out at a high temperature of as high as 70°C, so the air taken out from the pipe 22 after coming into contact with the concentrated human waste during fermentation has a sufficiently high temperature, for example, about 50°C. ~60°C, and has a sufficient amount of heat as a heat source for heating the heat medium compressed by the compressor 7 and the gas sent from the heat exchanger 9 to the housing 2 by the heaters 8 and 12, respectively. For example, exhaust gas at about 30° C. taken out from the housing 2 through the pipe 13 was cooled to about 15° C. while passing through the heat exchanger 11, but instead of passing through the heat exchanger 9 and the heater 12. Thus, it was heated to about 40°C.

In the above embodiment, two heaters 8 and 12 are provided to save energy, but one or both may be omitted.

Furthermore, if the human waste is oxidized in advance before drying in the dryer 1, it will be sterilized and odor substances will be removed, making it easier to handle. This oxidation can generally be carried out by an aeration treatment for several days, but an oxidizing agent such as ozone or chlorine may also be used.

As described above, according to the present invention, human waste can be dried and composted in a closed system through the stirring process, human waste drying process, fermentation process, and fermentation heat utilization process. This prevents large amounts of odorous exhaust gas from being released into the atmosphere.
In addition, heat can be easily recovered and reused, resulting in less energy consumption. Furthermore, since drying is performed at a low temperature of 100° C. or lower, most of the gases generated are ammonia and water vapor, and this gas can be easily treated by chemical treatment alone. In addition, since ammonia is removed from the concentrated human waste obtained by drying, there is no bad odor and there is little risk of emitting a bad odor during fermentation. Moreover, since no additives are added, the organic matter content is high and the amount of heat generated during fermentation is large. Therefore, the desired fermentation can be carried out simply by returning a portion of the compost to the fermentation tank, and there is no need to add sawdust or the like. Since human urine is dried at low temperatures, sterilization of Escherichia coli and the like is insufficient, but this is not a problem since sterilization is carried out during the fermentation process.

[Brief explanation of drawings]

The figure is a flow sheet showing an example of the steps of the method of this invention. DESCRIPTION OF SYMBOLS 1... Dryer, 2... Housing, 3... Rotating shaft, 4... Disc, 7... Compressor, 8... Heater, 9... Heat exchanger, 10... Pressure reducing valve, 11...
...Heat exchanger, 12... Heater, 18... Fermenter.

Claims (1)

[Claims] 1. A stirring process in which human waste to be treated is supplied into a dryer having a large number of rotating disks in a sealed housing, and the human waste is stirred by the rotating disks, and the above-mentioned housing in which this stirring process is performed. The gas extracted from the heat pump is cooled by the heat exchanger of the heat pump, the condensed water generated by this cooling is removed, and then heated to a temperature of 100°C or less by another heat exchanger of the heat pump, and then released into the housing. A human waste drying step in which the heated gas is used to dry the human waste at the same time as the stirring step, and the concentrated human waste dried in this human waste drying step is fermented in a sealed fermentation tank. A method for drying human waste, comprising a fermentation step for composting, and a fermentation heat utilization step for using the heat generated in the fermentation step to heat the heat medium of the heat pump or the gas returned to the housing.