JPS58174233A - Method for granulating dehydrated cake and concentrated sludge - Google Patents

Abstract

PURPOSE:To granulate dehydrated cake and concd. sludge to a desired and uniform grain size which is suited for post treatments by disintegrating said cake and sludge and granulating the disintegrated material further by using a known granulator. CONSTITUTION:Dehydrated cake or concd. sludge produced by a dehydration treatment of industrial waste water and sewage is disintegrated with a disintegrator 2 and the disintegrated material produced by said disintegration is further granulated by using a known granulator 4 in a method of granulating said cake and sludge so as to be made suitable for post treatments. The method is more advantageous if the dehydrated cake of particularly a high moisture content is disintegrated and granulated after dried powder such as dust collecting ash or lime powder is added thereto. In other words, the fine particles in the disintegrated material are granulated to spherical particles of a desired size, and the other particles can be formed to a roughly spherical shape by rounding the corners thereof, whereby the disintegrated material having a uniform grain size is obtained. Since the fine particles are granulated to a specified size, the production of dust in succeeding handling is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for granulating dehydrated cake and concentrated sludge generated by dehydration treatment of industrial wastewater and sewage so as to be suitable for subsequent treatment.

Conventionally, granulation has been carried out by mixing, for example, a dehydrated cake obtained by dehydrating a slurry liquid of converter dust or blast furnace dust from a steel mill with dried powder in a mixer. However, since moisture comes out when the dehydrated cake is pressed with a mixer, a large amount of dry powder was required. Furthermore, the particles obtained by the mixer were mixed with fine particles and coarse particles, and the particle size was not uniform. This was very inconvenient when a particle size above a certain level was desired in subsequent processing. Furthermore, there is equipment that crushes the dehydrated cake to make it suitable for subsequent processing, but the crushed material contains a considerable amount of fine particles, and 5 to 10% of the particles are within 1 diameter. However, there was a drawback that such fine particles caused dust generation during subsequent handling.

The object of the present invention is to eliminate the above-mentioned drawbacks and to provide a method for granulating a dewatered cake or thickened sludge into desired and uniform straight granules suitable for further processing.

The above object is achieved according to the present invention by crushing a dehydrated cake or thickened sludge and further granulating the resulting crushed material using a known granulator. Particularly for a dehydrated cake with a high water content, it is advantageous to add dry powder such as collected ash or lime powder, followed by crushing and granulation. Further, as the granulator, a pan-type or drum-type granulator that performs granulation by transferring particles can be used.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below with reference to embodiments.

FIG. 1 shows an array of equipment for carrying out the method of the invention. 1 is a belt conveyor for conveying a dehydrated cake obtained by dehydrating industrial wastewater to a crusher 2.

As the crusher 2, it is convenient to use a crusher of the type described in the specification of patent amount J filed on January 29, 1980. The dehydrated cake fed by a material pushing car with a rotary blade is sheared and crushed at high speed by a stationary blade and a rotating blade that rotates at high speed.

The crushed material is fed into a well-known drum-type granulator 4 by a belt conveyor 6 located below, and is granulated into pellets of a desired particle size by being transferred within a slowly rotating drum. The pellets are fed to a predetermined location by a belt conveyor 5.

FIG. 2 shows another example for implementing the method of the invention.

Reference numeral 11 indicates a belt conveyor for conveying the dehydrated cake to the crusher 12. If the dehydrated cake has a particularly high water content,
It is necessary to add dry powder in order to prevent the dehydrated cake from adhering to the inside of the crusher or the crushed materials from adhering to each other and forming lumps. For this purpose, a hopper 16 for storing powder is provided in the middle of the belt conveyor 11,
A metering feeder 14 is provided to feed powder in a metered amount.

After crushing the dehydrated cake in a crusher 12 similar to the type of crusher described above, the crushed material is conveyed by a peltoco/veyor 15 and charged into a well-known pan-type granulator 16, which rotates slowly. It is granulated into pellets of a desired size by rolling in a table.

The pan-type granulator 16 is equipped with a device for adding an additive liquid to control the size of the particles to be granulated. This device includes an additive tank 17, a pump 18, a control valve 19,
It consists of a conduit 20.21 and a spray nozzle 22. The granulated pellets are transferred from the outlet of the granulator 16 to the chute 2.
3 to a belt conveyor 24, and is fed to a predetermined location by the belt conveyor 24.

25 indicates a granulated pellet. As in this example, even with a high water content dehydrated cake, the surface was covered with powder by adding powder. Since crushed materials with no water coming out to the surface can be obtained, they can be granulated into particles of a constant particle size using a granulator.

In the method of the present invention, the dehydrated cake is crushed and the resulting crushed material is further granulated using a conventional granulator, so that the fine particles in the crushed material are granulated to the desired size. In addition to forming spherical particles, other particles can be rounded to form particles close to spherical, thereby making it possible to obtain a crushed material with uniform particle size. Furthermore, since the fine particles are granulated to a certain size, it is possible to suppress the generation of dust during subsequent handling.

[Brief explanation of the drawing]

FIG. 1 shows an example of an apparatus for implementing the method of the invention, and FIG. 2 shows another example of an apparatus for implementing the method of the invention. 15.5.11.15.24... Belt conveyor 2.12... Crushing machine 4.16... Granulator 14... Powder quantitative feeder

Claims (1)

[Claims] (]) A method for granulating dehydrated cake and concentrated sludge generated by dehydration treatment of industrial wastewater and sewage so as to be suitable for subsequent treatment, A method characterized by further granulating the crushed material using a known granulator. (2) Dry powder is added to the dehydrated cake with particularly high water content, and then crushed and granulated.
The method described in section. (3) The method according to claim 1, wherein the granulator is a pan-type or drum-type granulator that performs granulation by transferring particles.