JPS589719B2 - Sludge treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sludge treatment apparatus, and its purpose is to provide an apparatus that can easily and significantly reduce the water content of sludge.

Conventionally, aged surplus activated sludge after activated sludge treatment has been disposed of by dumping it in a landfill or burning it.

However, disposing of the sludge in a landfill etc. poses a pollution problem due to organic substances in the surplus activated sludge, and dehydration treatment such as centrifugation before combustion does not sufficiently dehydrate the water inside the microbial cells. However, the dehydration is only about 80%, and the combustion process requires a large amount of fuel.

BACKGROUND OF THE INVENTION In recent years, there has been a strong desire to control pollution and reduce fuel consumption, and there has been a strong desire to create a treatment device that can reduce the moisture content of sludge without causing pollution problems and requiring less fuel consumption.

In view of the above circumstances, the inventor has created a device for destroying microbial cells according to a separate application filed at the same time. This device decomposes and activates the cell-destroyed sludge using high-pressure discharge, oxidizes it with oxygen, and removes the water that has been adsorbed and coordinated with organic matter, thereby significantly reducing the water content of the sludge. We succeeded in reducing the amount of sludge and created this sludge treatment equipment.

Hereinafter, one embodiment of the sludge treatment apparatus according to the present invention will be described in detail based on the drawings.

In the figure, 1 is a sludge treatment tank composed of a top wall 2, a bottom wall 3, an inner wall 4, a side wall 5, and an internal space 6, and usually has a capacity of about 1000 liters.

The shape and capacity of the sludge treatment tank 1 can be freely changed depending on the setting conditions such as the installation area and the amount of sludge treated.

Further, the sludge treatment tank 1 is integrally formed using a heat-resistant material for each wall 2, 3, 5, and has airtightness and pressure resistance.

The upper wall 2 is connected to a sludge supply pipe 7 that supplies sludge whose cells have been destroyed by a microbial cell destruction device (not shown) to the sludge treatment tank 1, and the internal pressure inside the sludge treatment tank is 5 kg/cm2. A safety valve 8 and a discharge valve 9 for discharging gas such as water vapor generated during sludge treatment are provided.

Reference numeral 10 denotes a discharge pipe disposed at the center of the lower wall 3 for discharging treated sludge.

11 is a perforated plate fixed from the top end 12 of the discharge pipe 10 to the lower vicinity portion 13 of the discharge pipe neck end and the inner wall 4;
This porous plate opening has a required slope from the vicinity portion 13 toward the inner wall 4.

The inclination angle .theta. of the perforated plate 11 used in the apparatus of this invention is set within a range that allows for sufficient oxygen supply and for appropriately discharging sludge after treatment.

Further, the diameter of the holes 14 formed in the perforated plate 11 is set to a size that allows gases such as air to pass through but does not allow solids such as sludge to pass through.

Reference numeral 15 denotes a pipe for supplying air, etc., which is disposed on the side wall 5 below the location where the perforated plate 11 is fixed to the inner wall 4.

Reference numeral 16 denotes electrodes that are disposed opposite to each other at the central periphery above the perforated plate 11 in the internal space 6, and usually three pairs of electrodes are disposed opposite to each other at a required distance.

As for the material of this electrode 16, platinum metal or carbon material with good discharge performance and durability is usually used. In particular, when carbon material is used, it plays a catalytic function in oxidation after decomposing and activating the sludge.

Capacity such as voltage and current applied to the electrode 16 and each electrode 1
The distance between the electrodes 16, the shape of the electrodes 16, etc. shall be determined as appropriate depending on the nature and amount of sludge to be treated, and depending on the amount of sludge to be treated, it may be necessary to use only the electrodes 161, only the electrodes 161, 162, or all the electrodes 161, 162, 163, etc. Apply current while changing as appropriate.

Reference numeral 17 denotes a positive electrode to which a positive current is applied to generate oxygen, and is provided apart from the electrode 16 provided oppositely.

This anode 17 is connected to the hole 1 of the perforated plate 11 from the supply pipe 15.
It is used when the supply of oxygen through 4 is insufficient, etc.
The required number is provided depending on the amount of oxygen required.

The sludge treatment apparatus having such a configuration first supplies cell-destroyed sludge into the sludge treatment tank 1 via the sludge supply pipe 7.

In the sludge treatment tank 1, according to the inventor's experimental analysis, part of the water in the cell-destroyed sludge supplied by high-pressure discharge between the electrodes 16 is decomposed, and subsequently hydrogen is exploded by a discharge spark. Shock wave ultraviolet rays and ultrasonic waves are generated and heat is generated, and due to the mutual action of these, the organic matter in the cell destruction sludge is decomposed and activated into radicals.

Oxygen supplied from the supply pipe 15 or the like acts on the sludge decomposed and activated in this manner, and gases such as carbon dioxide are generated.

Here, when the material of the electrode 16 is a carbon material, the above-mentioned oxidation effect is promoted.

In this way, by decomposing the cell-destroyed sludge into low-molecular weight molecules and further oxidizing it into gases such as carbon dioxide, the water that was adsorbed and coordinated with the organic matter in the sludge is desorbed, increasing the water content of the cell-destroyed sludge. is lowered.

The cell-destroyed sludge that has undergone this treatment process is discharged through the discharge pipe 10.
It is discharged through the system and sent to an unillustrated combustion device, etc.

As detailed above, the sludge treatment device according to the present invention, together with the above-mentioned microbial cell destruction device filed on the same day, can easily significantly reduce the water content of aged surplus activated sludge, and is therefore superior to the conventional sludge treatment device. This greatly improves the disadvantages of the combustion treatment of aged surplus activated sludge, which requires a large amount of fuel and is expensive.

Next, the effects of the present invention will be made clearer by describing test examples of the sludge treatment apparatus according to the present invention.

Test Example Cell-disrupted sludge with a moisture content of 90 to 98% was placed in a sludge treatment tank.
00l was supplied.

The device shown in the previous example is used for this sludge treatment tank,
That is, three pairs of electrodes are provided, and each electrode is applied with a voltage of 60
0 ■, and a direct current of 80 kW, h was applied.

Next, 5 m3 of air was supplied per minute to the sludge treatment tank to perform sludge treatment.

When cell-destroyed sludge at a temperature of 70 to 80°C is supplied into a sludge treatment tank, a gas explosion occurs in the tank due to high-pressure discharge between the electrodes, and the temperature inside the tank rises to around 150°C, followed by the decomposition of organic matter. As a result, the temperature inside the tank reached around 200°C, and the organic matter in the decomposed and activated sludge was oxidized.

Note that the time required for this treatment was about 1 minute.

Results 3 to 4 of measuring the moisture content of treated cell-disrupted sludge
It decreased to about %.

In FIG. 2, a straight line A shows the change in temperature inside the device over time in this test example.

The results of this test example also clearly show that the device of the present invention has the effect of extremely reducing the water content of sludge in a short period of time.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory cross-sectional view of an embodiment of the present invention, and FIG. 2 shows changes in the temperature inside the tank over time in a test example. 1...Sludge treatment tank, 2...Top wall, 3
...Bottom wall, 4...Inner wall, 5...
...Side wall, 6...Internal space, 7...
Sludge supply pipe, 8...Safety valve, 9...
・Exhaust valve, 10...Exhaust pipe, 11...
... Porous plate, 13 ... Near the bottom of the top of the discharge pipe, 15 ... Supply pipe, 16 ... Electrode.

Claims (1)

[Claims] 1. Sludge supply that supplies sludge with destroyed microbial cells to the top wall of a sludge treatment tank with a capacity of approximately 1000 liters, in which the top wall, bottom wall, and side walls are integrated to maintain airtightness and pressure resistance through insulation. A pipe, a safety valve and an exhaust valve that operate at a pressure above 5ky/cm21 are installed, and a sludge discharge pipe for discharging treated sludge is installed in the center of the bottom wall. Three pairs of electrodes were attached to decompose and activate the organic matter into radicals, and a hole was drilled through which air, etc. supplied from the supply pipe installed at the bottom of the side wall was supplied to the decomposed and activated organic matter. A sludge treatment device comprising: a perforated plate that is slanted as required from near the top end of the discharge pipe toward the inner wall and fixed to the inner wall.