JPS593239B2 - Method and equipment for adding flocculant in sludge treatment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for adding a flocculant in sludge treatment.

When treating sludge, it cannot be directly dumped due to its high moisture content, so it is dehydrated mechanically or chemically mechanically to a moisture content that can withstand transportation or dumping.

Depending on the type of sludge, if direct mechanical dewatering is not possible, a flocculant is added to the sludge and stirred to form flocs of sludge particles, followed by mechanical dewatering. However, to add this flocculant, the flocculant and sludge are supplied to a mixing tank and mixed by stirring with an agitator, or the flocculant and sludge are put into a rotating drum and the drum rotates to mix the flocculant and sludge. are doing. However, this method requires 15% of power to stir the flocculant, and because a large amount of flocculant is injected into a specific location, more flocculant than necessary acts on the sludge particles in some areas, and the crosslinking effect of the polymer flocculant is impaired. It may be insufficient. In view of this, the present invention was made with the aim of uniformly mixing the flocculant and stirring without requiring 20% of power, and with a simple device.
The following description will be made based on the illustrated embodiment.

In the figure, 1 is the main body of the addition device that adds and mixes flocculant to sludge at the required mixing ratio.This is a pipe equipped with flanges at both ends so as to be connected to a part of the sludge supply 25 supply pipe. In addition to the shape, a large number of flocculant addition pipes 2 are provided inside the main body from the outer peripheral surface of the main body 1.

Therefore, the diameter of the main body is determined to be the same as or slightly larger than the diameter of the sludge supply transfer pipe 3. 30 A large number of flocculant addition pipes 2 provided on the outer periphery of the main body are arranged in a spiral pattern along the axis along the outer peripheral surface of the main body, and the sludge transferred inside the main body has a diameter that causes a vortex flow due to the addition pipes 2. The length of each addition tube 2 is determined so that the tip of the addition tube 2 has a slight gap from the inner 35 surface of the main body 1. Although it may be fixed, as shown in Fig. 4, the addition tube 2 can be slidably inserted into the boss 1a protruding from the outer periphery of the main body in an airtight manner, and the protrusion amount can be adjusted to any desired position using a locking tool such as a lock bolt 1b. It may be fixed in an adjustable manner.

Furthermore, a flocculant supply pipe 4 is connected to the outer ends of the many flocculant addition pipes 2. To add and mix the flocculant in the apparatus configured as described above, the flocculant is added to the sludge amount from each addition pipe 2 at a predetermined ratio to the amount of sludge while the sludge is transferred into the main body at the required pressure and flow rate. When sludge is added little by little, the suspended matter in the sludge flows down the addition pipe that is tilted in the downstream direction without being caught, and the sludge collides with the outer circumferential surface of this addition pipe, acting like a stirring bar, creating a vortex flow downstream. (turbulent flow) is generated and stirred.

Since the flocculant is added little by little in or near the vortex, uniform addition of the flocculant and efficient mixing and agitation are achieved. Furthermore, by changing the amount of protrusion of the addition pipe into the main body, the most efficient mixing and stirring can be performed depending on the quality of the sludge, the amount of flocculant added, etc.

According to the present invention, a large number of flocculant addition pipes are provided in a tubular body designed to transport sludge and are inclined downstream from the outer peripheral surface of the main body, and the outer periphery of the addition pipes creates turbulence in the sludge flow. A small amount of flocculant is added from each addition tube to the transported sludge from multiple locations within the main body, so the flocculant is added uniformly, and mixing and stirring does not require external stirring power, and the simple structure allows for efficient addition. It has the advantage of being able to be mixed.

[Brief explanation of the drawing]

1 is a schematic diagram, FIG. 2 is a front view, FIG. 3 is a vertical side view, and FIG. 4 is a partially enlarged sectional view. 1...Body, 1a...Boss, 1b...
... Lock bolt, 2 ... Coagulant addition pipe,
3...Sludge supply transfer pipe, 4...Flocculant supply pipe.

Claims (1)

[Scope of Claims] 1. A Karman vortex is generated by the flowing energy of the sludge transferred within the tubular body through a large number of flocculant addition pipes which are inclined in the direction of flow and protrude from all directions within the body. 1. A method for adding a flocculant in sludge treatment, characterized in that the flocculant is added from each addition pipe into a vortex flow, and uniform addition stirring and mixing is forcibly performed. 2 A large number of flocculant addition pipes are arranged in a tubular body connected to a sludge transfer pipe so as to protrude into the interior from all angles of the outer peripheral surface, and each of these addition pipes is inclined in the downward direction of sludge flow. 1. A flocculant addition device for sludge treatment, characterized in that the flocculant addition device is protruded to a length sufficient to cause a Karman vortex flow in the fluid.