JPH0221879B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides rotating blades for scraping up various types of sludge such as water treatment sludge such as sewage sludge and industrial waste sludge in a heating chamber surrounded by a horizontal drum-shaped heating wall. The present invention relates to a method of drying using a dryer.

The above method is intended to bring the sludge into contact with the heating wall over a wide area in the circumferential direction by the action of the rotating blades, and to be able to perform a large-volume drying process considering the capacity of the heating chamber. Conventionally, to carry out the above method, as shown in FIG. While being fed, the material was dried by the steam supplied to the jacket 8 and the rotary blade 5, resulting in the following drawbacks. In other words, the sludge supplied to the heating chamber 1 is transported by the pump channel 12 to the heating chamber 1 or
Due to the thixotropic phenomenon accompanying the stirring by the rotary blades 5, and furthermore, the heating in the heating chamber 1 causes the sludge to flow more easily, resulting in insufficient scraping of the sludge by the rotary blades 5, which causes the sludge to interfere with the heating wall 7. The technical intention of increasing the drying efficiency by increasing the contact area was often not fully achieved.

The object of the present invention is to, by extremely simple means,
Even if the sludge is fluid before it is supplied to the dryer, or even if it becomes fluid during drying, the rotating blades should be able to sufficiently scrape up the sludge to ensure efficient drying. The purpose is to ensure that processing can be carried out reliably.

The characteristic means of the method of the present invention is that a part of gel-like sludge taken out from a heating chamber surrounded by a horizontal drum-shaped heating wall and equipped with rotary scraping blades is added to the sludge supplied to the heating chamber. The purpose is to mix the sludge in such a way that the fluid state of the sludge is suitable for sludge scraping by the rotating blades.

The effects of the above characteristic means are as follows.

In other words, even with an extremely simple operation or equipment in which a part of the dried sludge is simply mixed into the sludge to be dried before being supplied to the heating chamber or within the heating chamber, the fluidity of the sludge in the heating chamber can be controlled. The sludge can be adjusted to be sufficiently scraped up by the rotating blades, and as a result, the sludge can be brought into contact with the heating wall over a sufficiently large area, increasing the drying capacity in relation to the capacity of the heating chamber. , can now be carried out reliably regardless of the properties of the sludge.

Next, an example will be shown with reference to FIGS. 1 and 2.

Horizontal drum-shaped heating chamber 1 provided in dryer A
The dried and dewatered sludge is introduced from the supply port 2, and is scraped up and stirred in the heating chamber 1 by the rotary blades 5 rotated by the action of the electric motor 3 and the speed reducer 4, while being pumped through the discharge port 6. A heating fluid such as steam that is moved toward the heating chamber 1 and flows from the inlet 9a to the outlet 10a within the jacket 8 surrounding the heating wall 7 via the heating wall 7 surrounding the heating chamber 1 and the rotating blade 5; Inlet 9 within rotating blade 5
The sludge in the heating chamber 1 is dried by a heating fluid such as steam flowing from b toward the outlet 10b, and the gel-like dried sludge is taken out from the discharge port 6, and the sludge is continuously heated using an indirect heating method. be dried.

A portion of the gel-like sludge taken out from the discharge port 6 is sent to the mixing device 13 via conveyors 11a and 11b, where it is continuously or intermittently mixed with the sludge supplied to the heating chamber 1, and heated. The flow state of the sludge in the chamber 1 is adjusted so that the sludge is sufficiently scraped up by the rotary blades 5, and the contact area between the heating wall 7 and the sludge, in other words, the contact width l in the circumferential direction of the heating chamber is made sufficiently large. Adjust to

By adjusting the position of the movable hopper 14, the mixing ratio of gel sludge to the sludge to be dried is adjusted.
The former is set to improve the drying efficiency depending on the properties and moisture content of the sludge, as well as the dryer A conditions such as the diameter of the heating chamber 1, but in general, the average moisture content is 60 to 65 wt%. Mix until evenly mixed.

Next, another example will be shown.

The gelled sludge taken out from the discharge port 6 can be continuously or intermittently fed into the heating chamber 1 at an appropriate position in the sludge transfer direction, or the gelled sludge can be mixed manually. can.

Various modifications can be made to the configuration of the dryer A, such as changing the shape of the rotary blades 5, for example.

[Brief explanation of drawings]

Fig. 1 is a schematic vertical cross-sectional view illustrating a dryer used in the method of the present invention, Fig. 2 is a cross-sectional view taken along the line - - in Fig. 1, and Fig. 3 is a schematic longitudinal cross-sectional view of a dryer used in the conventional method. It is a diagram. 1... Heating chamber, 5... Rotating blade, 7... Heating wall, A... Dryer.

Claims (1)

[Claims] 1. A method of drying sludge using a dryer A equipped with rotary raking blades 5 in a heating chamber 1 surrounded by a horizontal drum-shaped heating wall 7, in which sludge is removed from the heating chamber 1. A sludge drying method characterized in that a part of gel-like sludge is mixed into the sludge supplied to the heating chamber 1 so that the fluid state of the sludge becomes suitable for sludge scraping by the rotary blades 5. .