JPS63224799A - Dehydration of sludge or the like - Google Patents

Abstract

PURPOSE:To improve the efficiency of dehydration operation of sludge or the like, by transporting sludge or the like under pressure through a pipeline with a pump, compressing the sludge or the like to the inside of a cylindrical screen connected to an exit of the pipeline, separating water from solid matters with the screen, and heating the transported sludge or the like in the pipeline during this stage. CONSTITUTION:Sludge or the like is transported under pressure through a pipeline with a pump 1, compressed to the inside of a cylindrical screen 3 connected to an exit of the pipeline 2, and water is separated from solid matters with the screen3. In this stage, the compressed sludge or the like in the pipeline 2 is heated with a heating apparatus 4 covered with a heating pipe 4'. As the result, the water in the highly hydrous sludge or the like is separated from solid matters continuously, thus the operation efficiency is elevated. Simultaneously, no expensive coagulant is required and degree of heating is reduced. Consequently, the dehydration efficiency is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method for dewatering sludge and raw materials with high water content generated from sewage, urine collection, and septic tanks thereof.

"Prior Art" Solid sewage sludge consists of hydrophilic colloid particles and contains a large amount of water inside. Heating the sludge increases the thermal motion of the particles, increases the frequency of particle collisions and associations, and eventually leads to interparticle agglomeration.

In addition, in hydrogels that contain a considerable amount of protein, such as sewage sludge, the gel structure is disrupted by heat, causing so-called syneresis, in which a large amount of built-in water separates. Furthermore, the organic matter undergoes hydrolysis due to heat and progresses to solubilization or liquefaction.

In other words, heat treatment of sludge causes thermal aggregation (molecular kinetic phenomenon), destruction of the gel structure and separation of internal water (syneresis phenomenon), and hydrolysis of organic matter (liquefaction phenomenon). , these phenomena do not occur in stages, but progress simultaneously and overall. Furthermore, the degree of effectiveness of heat treatment is greatly influenced by the properties of the sludge, treatment time, treatment temperature, and treatment atmosphere.

This heat treatment method improves the solid-liquid separability of sludge by keeping the sludge at a high temperature for a certain period of time. Table 1 shows the currently used heat treatment methods and reaction conditions. As shown in Table 1, heat treatment methods include high temperature methods and low temperature methods.

In both high temperature methods, sludge is reformed by heating it at 200°C (pressure: 18M) for about 1 hour in an oxygen-free condition. Since the dewaterability of sludge is significantly improved by such modification, it is an extremely effective method for conditioning sludge.

Table 1 (Sludge treatment engineering, written by Masakatsu Hiraoka, published by Kodansha, 1st edition 198)
3.9.20, pl 11). However, the dewatering of the sludge with a high water content involves separate steps of sludge transport, air injection, heating, and dewatering, making it difficult to use a continuous process.

[Problems to be Solved by the Invention-1] The object of the present invention is to simplify the dewatering work by continuously carrying out the process of transporting, heating, and dehydrating sludge and the like.

"Means for Solving the Problems" The present invention involves pumping sludge through piping, squeezing it into a cylindrical screen connected to the outlet of the piping, and separating water and solids through the screen. At this time, it is constituted by a method of dewatering sludge, etc., which is characterized by heating the sludge fed under pressure within the pipe.

Therefore, when sludge, etc. with a high water content is pumped into the pipe 2 by the pump 1, the sludge, etc. is forced into the cylindrical screen 3 connected to the outlet of the pipe 2, and the water is discharged from the screen 3, and the water is removed. The dehydrated sludge that has decreased is discharged from the end of the screen 3.

During the pressure-feeding process in the pipe 2, the high water-containing pressure-fed sludge is heated, which destroys its gel structure and promotes the separation of water and solids. Solid matter is separated. In addition, the above-mentioned heating is used only to increase the temperature without being stimulated by the latent heat of vaporization of the sludge under pressure.

"Example" A gelatinous sludge 5 with a high water content is put into a hopper, and from the same hopper is fed under pressure into a pipe 2 by a ping 1. As shown in FIG. 1, the large-diameter closed end of a truncated conical cylindrical screen 3 is connected to the outlet of the pipe 2, and the small-diameter end is opened. The ends are connected and communicated, and a conical plug 6 is slidably supported by a cylinder 7 in the opening of the other end, and a dewatered sludge discharge gap of 5tt is formed between the inner periphery of the opening and the outer periphery of the conical plug 6. . The piping 2 is provided with an air inlet 8, which is connected to an air compressor 9, and the piping 2 is covered with a heating tube 4' between the inlet 8 and the screen 3 to form a heating device 4. By connecting the pressure steam pipe 11 from the boiler 10 to the heating pipe 4, high-temperature steam can be injected into the heating pipe 4' to heat the pressure-fed sludge in the pipe 2, and the sludge can be heated by the heating. It is heat treated. Such heat treatment and the above-mentioned dewatering process are performed without interrupting the sludge pumping by the pump 1, and since the pumped sludge is under pressure, the above-mentioned heating is used only to raise the temperature, and is not stimulated by the latent heat of vaporization of water. do not have. In addition, what is indicated by M in the figure is the drive motor for pump 1.
12 is a screw that rotates by the fluid thrust of the pumped sludge to stir the sludge and scrape dirt off the heat transfer surface; 13 is a screw that rotates by the thrust of the sludge to scrape dirt on the f side of the screen 3; and 14 is a separated water hopper. , 15 is a dehydrated sludge storage box, and 16 is a drain port.

``Effects: Since the present invention is based on the method described above, it is possible to continuously separate water and solids from high water content sludge 5, etc., which not only improves dewatering efficiency but also eliminates the need for expensive flocculants. Moreover, the amount of heating can be reduced and the dehydration efficiency can be improved.

[Brief explanation of drawings]

FIG. 1 is a side view of an apparatus for carrying out the method for dewatering sludge, etc. of the present invention, and FIG. 2 is a side view of another embodiment of the method shown in FIG. 1. Pump, 2. Piping, 3. Cylindrical screen, 4
...Heating device.

Claims (2)

[Claims] (1) Sludge, etc. is pumped through piping, compressed into the inside of a cylindrical screen connected to the outlet of the piping, and water and solids are separated by the screen, at which time the sludge in the piping is A method for dewatering sludge, etc., characterized by heating. (2) A method for dewatering sludge, etc. according to claim 1, which comprises heating the air-injected and pressure-fed sludge.