JP3196172B2 - Screw stirring type sludge dryer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw stirring type sludge dryer for drying sludge as a pretreatment before incinerating and melting sludge. is there. [0002] As this kind of sludge dryer, a screw stirring type indirectly heated steam dryer is generally used. As shown in FIG. 5, this sludge dryer has a plurality of rotating shafts 3, 3 arranged in parallel in a casing 1 having a steam jacket 2 on the bottom and both sides, as shown in FIG. The rotary shafts 3 are provided with screw blades 5 such as spiral disks in which a number of half-moon disks 4 are spirally arranged at intervals. The sludge to be dried is introduced into the casing 1 through an inlet 11 provided at an upper part of the front end of the casing 1 and is stirred while being rotated by the rotating screw blades 5.
Due to the inclination of the fuselage, it is gradually fed to the rear part, during which the steam jacket 2, the rotating shafts 3, 3 and the discs 4, 4
It is heated and dried by the heated steam sent into the inside, and is taken out of the machine from the outlet 8 at the rear end. [0004] Incidentally, the above-mentioned sludge is fed by pumping sludge generated by water treatment through a pipe by a pump. To be transferred with a large pipe diameter to
Since the sludge is supplied from the upper part of the casing 1, the sludge is formed into a block and is supplied intermittently at intervals of 30 seconds to 2 minutes. For this reason, the sludge is transported in an uneven shape as shown by a chain line a in FIG.
And the heat transfer surface was not effectively used, which was not preferable in terms of drying efficiency. Therefore, in order to continuously feed sludge, a throttling mechanism is provided in the feeding pipe. However, there are drawbacks such as a large pressure loss, a large capacity pump, and a high running cost. SUMMARY OF THE INVENTION The present invention has been made to solve such problems in the conventional machine. The heat transfer surface can work effectively over the entire length of a screw blade such as a spiral disk, and the heat loss can be reduced. An object of the present invention is to provide an efficient and economical sludge dryer. The structure of the present invention for achieving the above object will be described with reference to the drawings corresponding to the embodiments. The present invention relates to a casing provided with a steam jacket 2. 1, a plurality of rotating shafts 3, 3 provided with screw blades 5 are disposed, and a jacket 2 and rotating shafts 3, 3 are provided.
In a dryer that supplies heated steam to the screw blades 3 and the screw blades 5 and transfers heat to the sludge charged into the casing 1, a sludge inlet 6 is provided between the rotating shafts 3 at the bottom of the front end of the casing. In addition, an air supply port 9 and a discharge port 10 are provided at an upper portion of the casing 1, and a discharge port 8 of the dried sludge is provided at a lower rear portion of the casing 1. [0007] In the sludge dryer having the above structure, sludge is introduced from the bottom of the front end of the casing 1. Therefore, the sludge pumped by the pump is continuously pushed out to the bottom, continuously scraped by the rotating screw blades 5, scraped up, broken up, and broken down by the chain line b in FIG.
As shown by, the screw blade 5 moves rearward while making contact with the respective disks 4 and 4 of the screw blade 5. At that time, the steam jacket and screw blade 5
The casing 1 is dried by heating with the rotating shafts 3 and 3 and the heat inside the casing 1, and is taken out as dry sludge from an outlet 8 at a lower rear end of the casing 1. An embodiment of the present invention will be described below with reference to the drawings. 1 and 2, reference numeral 1 denotes a casing,
The lower half is formed in the steam jacket 2 by a double wall, into which heated steam is supplied. In the casing 1, two hollow rotary shafts 3 are arranged side by side. On each rotary shaft, a large number of half-moon-shaped hollow disks 4 and 4 as screw blades 5 are provided at required intervals. And a spiral disk is formed. The hollow portion of each disk 4 communicates with the hollow portion of the rotating shaft 3 so that the heated steam supplied to each rotating shaft flows into each desk 4. Also, at the bottom of the front end of the casing 1,
An inlet 6 for sludge is provided at a position between the plurality of rotating shafts. A dam 7 and a discharge port 8 for sludge are provided at a lower rear portion of the casing 1, and an air supply port 9 is provided at an upper rear portion of the casing 1.
An air outlet 10 is provided in the upper front part. In the sludge dryer having the above structure, the heated steam is passed through the steam jacket 2 and the rotary rollers 3 and 3, and the sludge is introduced into the casing 1 through the inlet 6 at the bottom of the front end. The supplied sludge moves rearward with the inclination of the casing while being stirred by the disks 4 and 4 which rotate with the rotation of the rotating shafts 3 and 3. At that time, the steam jacket 2 and each disk 4,
4 and the rotating shafts 3 and 3 are heated while being heated by the air in the casing 1 warmed by them, and gradually dried, flowing over the weir board 7 and drying from the discharge port 8. The sludge will be taken out of the machine. The moisture evaporated by the drying of the sludge is discharged and removed outside the machine by the air that enters through the supply port 9 and exits through the discharge port 10. FIG. 3 shows another embodiment of the present invention. In this embodiment, three rotating shafts 3 are arranged in parallel. In this case, a plurality of sludge inlets 6, 6 are provided at respective intermediate positions of the rotating shafts 3, 3. In addition,
The number of rotating shafts 3, 3 and the number of sludge inlets 6, 6 associated therewith can be further increased. FIG. 4 shows still another embodiment of the present invention. In this embodiment, the sludge inlet 6 is not provided upward as in the previous embodiment, but is provided horizontally on the front end wall of the casing 1. In this embodiment as well, the inlet 6 is preferably located between each rotation as in the previous embodiment. In each of the above embodiments, the screw blade 5 is formed as a spiral disk by providing a large number of disks 4, 4 on the rotating shaft 3 at intervals. However, the present invention is not limited to this. Instead, the screw blade 5 can be continuous over the entire length of the rotating shaft 3. Also in this case, the screw blade is made hollow,
Heated steam can flow into it. As described above, according to the present invention,
Since sludge is introduced from the bottom of the front end of the casing, there is no need to provide any special means such as a squeezing mechanism in the sludge introduction pipe. As a result, the sludge moves rearward while being in contact with the entire surface of the screw blade, so that the heat loss is small and the drying efficiency is greatly improved.

[Brief description of the drawings] FIG. 1 is a side sectional view showing one embodiment of the present invention. FIG. 2 is a front sectional view of the same. FIG. 3 is a front sectional view showing another embodiment. FIG. 4 is a side sectional view showing still another embodiment. FIG. 5 is a side sectional view showing a conventional machine. [Explanation of symbols] 1 casing 2 steam jacket 3 Rotation axis 4 disks 5 Screw blade 6 Sludge inlet 7 cough plate 8 Sludge outlet 9 Air supply port 10 Air outlet 11 Sludge inlet

Claims (1)

(57) [Claims] A plurality of rotating shafts provided with screw blades are arranged in a casing provided with a steam jacket, and heated steam is supplied to the jacket, the rotating shaft and the screw blades, and injected into the casing. In a dryer that transfers heat to the sludge that has been made, a sludge inlet is provided between the rotation shafts at the bottom of the front end of the casing, and an air supply port and an exhaust port are provided at the upper part of the casing, and at the lower rear part of the casing. A screw stirring type sludge dryer characterized by having an outlet for dried sludge.