JPH0245519B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an energy-saving method for drying water-containing materials generated in the treatment of organic sewage such as sewage, human waste, and various industrial wastewater, and in particular to a method for drying water-containing materials. The present invention relates to a drying method that can be effectively applied when both a process and an aeration process of organic sewage and/or organic sludge coexist.

[Conventional technology]

Conventionally, drying hydrated materials generally requires a large amount of fuel such as heavy oil, kerosene, gas, or electricity.
This method was extremely energy consuming.

Furthermore, in the treatment of organic wastewater such as sewage, human waste, and various industrial wastewater, blowers have been installed for the purpose of supplying air for biological treatment and aerobic digestion of organic sludge.

[Problem to be solved by the invention]

Although these blowers only perform a single function, such as simply supplying air, there is no question about this, and there is no technical idea to give these blowers multiple functions. Nakatsuta.

The present invention was completed by focusing on the energy of the blower, which has not been considered at all in the past. In other words, since the blower is an air compressor, as shown in the adiabatic compression theory of gases in thermodynamics, the temperature of the blower discharge air will be much higher than the temperature of the suction air, and when the atmospheric temperature is 10 to 20 degrees Celsius. The present invention was developed by focusing on the fact that the temperature of blower discharge air reaches as high as 80 to 100°C.

An object of the present invention is to provide an energy-saving drying method that skillfully recovers and effectively utilizes the heat retained in blower discharge air and can dry water-containing materials without requiring any fuel. [Means for Solving the Problems] The present invention has a drying chamber for drying water-containing substances generated in organic wastewater treatment, which has a sealed structure, and the air inside the drying chamber is sucked by a blower, and the air discharged from the blower is The air is heated by the retained heat, and the resulting warm air is drawn into the drying chamber by the intake air of the blower and used as a heat source for drying, and the cooled blower discharge air is transferred to the refrigerant evaporation section of the heat pump At the same time, the heat released from the refrigerant condensing section of the heat pump is used as a heat source for drying in the drying chamber, and the low-temperature, low-humidity blower discharge air flowing out from the refrigerant evaporating section of the heat pump is used to cool and dehumidify organic wastewater. This is a method for drying a water-containing material, characterized in that it is used in an aeration process of organic sludge and/or organic sludge.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings, taking a sewage treatment facility as an example.

The wall A of the drying chamber 2, which has a closed structure and houses the dehydrated cake of sewage sludge and other water-containing solids 1 to be dried generated in sewage treatment facilities, is isolated from the outside air with a heat insulating material, and the air inside the drying chamber 2 is 3 is sucked and compressed by the aeration blower 4, but heat of compression is generated in this process, and the temperature of the blower discharge air 5 is
Raise the temperature to about 80-100℃. In order to recover the heat of this blower discharge air 5, the blower discharge air 5 is caused to flow into a heat exchanger 6 to heat the air 7, and the obtained warm air 7' is guided into the drying chamber 2 to dry the water-containing solids. Used as a heat source for drying item 1.

On the other hand, by heating the air 7 with the heat exchanger 6, the blower discharge air, which itself has been cooled, has
Since it contains a large amount of water vapor evaporated from the water-containing solid material 1 to be dried and becomes high humidity air 5',
The latent heat possessed by this water vapor is recovered and used as a heat source for drying. For this purpose, the high-humidity air 5' is cooled by contacting with a refrigerant evaporator 8 such as a fluorocarbon of a heat pump, the latent heat of condensation is recovered by pseudo-condensing the water vapor, and the generated condensed water is discharged from a drain 9.

Therefore, the refrigerant condensing section 10 of the heat pump
(heat dissipation section), the latent heat of water vapor condensation recovered from the high-humidity air 5' and the amount of heat equivalent to the power input to the refrigerant compression 11 of the heat pump (1kwH =
Since the total amount of heat (860Kcal) is dissipated, this heat is also used as a heat source for drying.

Note that 12 indicates a refrigerant expansion valve.

In addition, the low-temperature, low-humidity air 5'' flowing out from the refrigerant evaporation section 8 (refrigerant dehumidification section of the high-humidity air 5') of the heat pump still has a high pressure, and is used in the aeration tank 13 for activated sludge treatment of sewage. It is supplied to the aeration device 14 or used for aeration of organic sludge.

In addition, since the low-temperature, low-humidity air 5'' is supplied to the aeration tank 13 for activated sludge treatment of sewage, a special deodorizing process is not required.In other words, foul-smelling gas is generated when drying a dehydrated cake of sewage sludge. However, as this dry exhaust gas is supplied to the aeration tank 13 and used for aeration, it is biologically deodorized by the activated sludge microorganisms living in the aeration tank 13 in large quantities. , operating costs become unnecessary.

Note that the blower discharge air used as the drying heat source in the above-mentioned present invention also includes discharge air from an air compressor or the like.

Furthermore, other embodiments of the present invention will be described as follows.

When the blower 4 is installed in the drying chamber 2, the heat generated from the blower 4 body is dissipated into the drying chamber 2, increasing the amount of heat that can be used for drying.

The refrigerant condensing section 10 of the heat pump has a drying chamber 2
Alternatively, the heat exchanger 6 may directly exchange heat with humidified warm air 7'.

As the drying chamber 2, either a batch drying method or a continuous drying method can be employed.

〔Effect of the invention〕

As described above, the present invention recovers the heat retained in the air discharged from the blower, which conventionally only had a single function of simply supplying air, and effectively utilizes it for drying water-containing materials. The following very important effects can be obtained from this:

Since blower compression heat is used to dry water-containing materials, which conventionally required fuel such as heavy oil, there is a significant energy-saving effect and no drying fuel is required.

Since the latent heat of the water evaporated during drying of the hydrated material is recovered and used as a heat source for drying along with the compression heat of the blower, even more energy-saving drying is possible.

Since the drying chamber has a closed structure, hot air automatically flows into the drying chamber by the suction force of the blower, so there is no need to provide a separate fan.

As a result of drying water-containing materials, low-temperature, low-humidity air that retains pressure is automatically obtained, and this air can be used for aeration of organic wastewater and organic sludge, eliminating the need for aeration power. Become.

[Brief explanation of drawings]

The drawing is a system explanatory diagram showing an embodiment of the present invention. 1...Water-containing solid matter, 2...Drying room, 3...Air, 4...
Blower, 5...Blower discharge air, 5' high humidity air,
5″...Low temperature, low humidity air, 6...Heat exchanger, 7...Air,
7'... Warm air, 8... Refrigerant evaporation section, 10... Refrigerant condensation section,
11... Refrigerant compressor, 13... Aeration tank.

Claims (1)

[Claims] 1. A drying chamber for drying water-containing substances generated in organic wastewater treatment has a sealed structure, and the air inside the drying chamber is sucked by a blower, and the air is blown by the heat retained in the air discharged from the blower. The heated air is heated, and the obtained warm air is sucked into the drying chamber by the intake air of the blower and used as a heat source for drying, and the cooled blower discharge air is brought into contact with a refrigerant evaporation part of a heat pump to cool it.
In addition to dehumidifying, the heat dissipated from the refrigerant condensing section of the heat pump is used as a heat source for drying in the drying chamber, and the low temperature and low humidity blower discharge air flowing out from the refrigerant evaporating section of the heat pump is used to dehumidify organic sewage and/or organic sludge. A method for drying a hydrated material characterized by use in an aeration process. 2. The method of drying a water-containing material according to claim 1, wherein heat generated by the blower body is dissipated into the drying chamber.