JPH11300397A - Sludge drying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sludge drying device by which sludge is efficiently dried in a centrifugal thin-film drier. SOLUTION: This sludge drying device is provided with a centrifugal thin-film drier 1 having a heat-transfer drum 1a for drying the sludge and a sludge feed pipeline 2 for supplying the sludge into a heat-transfer drum 1a. The heating device 3 consisting of a piping 3a of the material resistant to induction heating and an electromagnetic induction heater 4 set outside the piping 3a is furnished to the sludge feed pipeline 2. The sludge in the pipeline 2 is heated by a heating device 3 to prevent the lowering of viscosity of the sludge, and the sludge is extended on the inner face of the drum 1a into film and surely dried.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sludge drying apparatus for treating sludge such as sewage sludge, and more particularly to a sludge drying apparatus capable of efficiently drying sludge.

[0002]

2. Description of the Related Art Conventionally, in the treatment of sludge such as sewage sludge,
A centrifugal thin film dryer having a heat transfer drum is used to dry sludge. In this centrifugal thin film dryer, the sludge supplied by the sludge supply pipe is stretched into a thin film in the heat transfer drum and dried.

[0003] At this time, if the water content of the supplied sludge is low, the viscosity of the sludge increases, so that when the sludge flows into the heat transfer cylinder of the centrifugal thin film dryer, the sludge hardly becomes a thin film in the heat transfer cylinder. As a result, the sludge layer becomes thicker and the drying efficiency decreases. Alternatively, pulsation occurs in the sludge supply to the centrifugal thin film dryer, and the moisture content of the sludge dried by the heat transfer drum of the centrifugal thin film dryer tends to be uneven. If the viscosity of the supplied sludge becomes extremely high, clogging may occur in the sludge supply pipe, and maintenance such as washing is required to eliminate the clogging.

[0004]

As described above, in order to improve the sludge drying efficiency of the centrifugal thin film dryer, it is necessary to prevent the water content of the supplied sludge from decreasing. Further, even when the water content of the supplied sludge decreases, the water content of the sludge dried by the centrifugal thin film dryer must be stably maintained at a low value.

[0005] The present invention has been made in view of such a point, and an object of the present invention is to provide a sludge drying apparatus capable of efficiently drying sludge.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a centrifugal thin-film dryer having a heat transfer drum for introducing sludge into the inside thereof and drying the sludge to produce dry sludge, and supplying the sludge into the heat transfer drum. And a heating device provided on the sludge supply pipe to heat the sludge.

According to the present invention, by heating the sludge in the sludge supply pipe by the heating device, it is possible to prevent the viscosity of the sludge supplied into the heat transfer drum of the centrifugal thin film dryer from decreasing.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a sludge drying apparatus according to the present invention will be described with reference to the drawings.

FIG. 1 is a system configuration diagram showing a first embodiment of a sludge drying apparatus according to the present invention.

As shown in FIG. 1, the sludge drying apparatus includes a centrifugal thin film dryer 1 having a heat transfer drum 1a for extending and drying sludge supplied thereto, and a sludge supply pipe for supplying sludge into the heat transfer drum 1a. 2 and a heating device 3 provided in the sludge supply pipe 2 for heating the sludge.

The heating device 3 includes an induction heating material pipe 3a interposed in the sludge supply pipe 2, and an electromagnetic induction heating device 4 disposed outside the induction heating material pipe 3a. I have.

A sludge supply pump 5 is connected to the sludge supply pipe 2.
Is connected. Further, the heat transfer drum 1 of the centrifugal thin film dryer 1
Outside of a, a heating steam inlet 6 and a heating steam outlet 7 into which heating steam for heating the heat transfer drum 1a flows are provided. The heat transfer drum 1a of the centrifugal thin-film dryer 1 has a blade (not shown) inside, and the blade rotates at several hundred rpm to spread the supplied sludge into a thin film and perform a drying process. . In the heat transfer drum 1a of the centrifugal thin-film dryer 1, odor gas is generated during drying of the sludge, and the odor gas is carried by the bleed gas blower 9 through the bleed gas pipe 8 to the deodorizer 10, where it is subjected to deodorization.

Next, the operation of the embodiment having the above-described configuration will be described. First, sludge is pressure-fed by a sludge supply pump 5 and is fed into the heat transfer drum 1a of the centrifugal thin film dryer 1 via the sludge supply pipe 2. In the heat transfer drum 1a, the sludge is spread on the inner surface of the heat transfer drum 1a, and is heated and dried by the steam flowing from the heating steam inlet 6. In this case, the steam flows in from the heating steam inlet 6 to heat the outer surface of the heat transfer drum 1a, and then flows out from the heating steam outlet 7.

During this time, the sludge passes through the induction heating material pipe 3 installed in the sludge supply pipe 2. At this time, the sludge in the induction heating material pipe 3 is heated by the electromagnetic induction heating device 4, and the viscosity of the sludge decreases. Thus, the sludge can easily pass through the sludge supply pipe 2. In particular, when the outside air temperature is falling, such as in winter, such heating of the sludge is effective. Also, by feeding the heated sludge into the heat transfer cylinder 1a of the centrifugal thin film dryer 1, the heat transfer cylinder 1a
The drying process in the inside is also performed more efficiently, and it is possible to obtain a sludge having a stable low moisture content.

Here, for example, if the outside of the sludge supply pipe 2 is heated using another heat source such as heating steam, the heat will heat the outer periphery of the sludge supply pipe 2 and the sludge itself cannot be sufficiently heated. It is possible. On the other hand, according to the present invention, the sludge passing through the induction heating material pipe 3 can be uniformly heated from the outside and the inside by using the electromagnetic induction heating device 4 to prevent the viscosity of the sludge from decreasing. Can be. Therefore, the fluidity of the sludge is increased, and the sludge is transferred to the heat transfer cylinder 1.
a can be reliably extended in the form of a thin film on the inner surface.
The drying effect in the inside can be further enhanced. Further, since the sludge viscosity in the sludge supply pipe 2 can be prevented from lowering, sludge pulsation and blockage in the sludge supply pipe 2 can be prevented, and more stable operation can be performed. .

Next, a second embodiment of the sludge drying apparatus according to the present invention will be described with reference to FIG. In FIG.
The same parts as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and detailed description is omitted.

As shown in FIG. 2, an input sludge storage tank 12 is provided on the upstream side of the sludge supply pump 5, and the water content of the sludge supplied to the centrifugal thin film dryer 1 is detected on the sludge storage tank 12. Input sludge moisture content detector (first moisture content meter) 1
1 is provided.

A discharge conveyor 14 for discharging sludge dried by the centrifugal thin film dryer 1 is provided below the centrifugal thin film dryer 1. On this discharge conveyor 14, a dry sludge hydrate for detecting the moisture content of the dry sludge is provided. A rate detector (second moisture content meter) 13 is provided. Further, signals from the input sludge moisture content detector 11 and the dried sludge moisture content detector 13 are sent to a power supply adjusting device 15, and the output of the power supply induction heating device 4 is adjusted by the power supply adjusting device 15. .

In FIG. 2, measurement signals from the input sludge moisture content detector 11 and the dry sludge moisture content detector 13 are input to the power supply adjusting device 15. In the power supply adjusting device 15, when the water content of the input sludge detected by the input sludge water content detector 11 decreases, or when the water content of the dry sludge detected by the dry sludge water content detector 13 increases, The power supply of the electromagnetic induction heating device 4 is turned on. Furthermore, based on the measurement signals from the input sludge moisture content detector 11 and the dry sludge moisture content detector 13, when the moisture content of the input sludge greatly decreases or the moisture content of the dry sludge greatly increases,
The power supplied to the electromagnetic induction heating device 4 is increased by the power supply adjustment device 15, thereby strongly heating the sludge passing through the anti-induction heating material pipe 3.

In this way, when the water content of the input sludge increases and the viscosity increases, or when the water content of the dry sludge from the centrifugal thin film dryer 1 increases, these conditions are corrected, Pulsation and blockage of the sludge in the sludge supply pipe 2 can be prevented, and stable dry sludge with a low water content can be obtained.

The sludge drying apparatus shown in each of the above embodiments can be applied not only to the sewage sludge drying field but also to sludge drying in general.

[0022]

As described above, according to the present invention,
By heating the sludge fed into the centrifugal thin-film dryer through the sludge supply pipe, it is possible to prevent the viscosity of the sludge from lowering and to further enhance the drying effect in the centrifugal thin-film dryer. Further, pulsation and blockage of sludge in the sludge supply pipe can be prevented, and stable operation can be performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a sludge drying device according to the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the sludge drying device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Centrifugal thin film dryer 1a Heat transfer cylinder 2 Sludge supply piping 3 Induction heating material pipe 4 Electromagnetic induction heating device 5 Sludge supply pump 11 Input sludge moisture content detector 13 Dry sludge moisture content detector 15 Power supply adjustment device

Claims (2)

[Claims] 1. A centrifugal thin-film dryer having a heat transfer drum for generating sludge by drying sludge therein, a sludge supply pipe for supplying sludge into the heat transfer drum, and a sludge supply. A sludge drying device comprising: a heating device provided in a pipe for heating sludge. 2. A first moisture content meter for measuring the moisture content of sludge supplied to a centrifugal thin film dryer, and a second moisture content meter for measuring the moisture content of dried sludge dried by the centrifugal thin film dryer. The sludge drying device according to claim 1, further comprising an adjusting device for adjusting an output of the heating device based on signals from the first moisture content meter and the second moisture content meter.