JPS596398Y2 - Drying equipment for muddy materials - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a device that heats and dries a slurry material by heat conduction from a heating surface.

Sludge generated during wastewater treatment is dehydrated by mechanical dehydration using centrifugation, vacuum, pressurization, etc. In this mechanical dehydration, the dewatered sludge is a sticky slurry-like muddy material with a water content of 75 to 90%. be.

When this sludge is disposed of by incineration or by turning it into fertilizer, it contains too much moisture and requires a huge amount of auxiliary fuel for incineration, which is very difficult to handle.

Therefore, as a pretreatment, drying is performed to reduce the moisture content to 30 to 40%.
% will be required.

Drying is an operation that uses heat to remove moisture from raw materials, and it is important to supply heat uniformly to the material. Consideration must be given to ensuring that the heat receiving surface of the material is as large as possible and that the generated water vapor is removed quickly. Must be.

Traditionally, this type of muddy material is often dried using a rotary dryer, which evaporates water by contacting it with hot air.In order to increase the contact area with the hot air, a chain or stirring device is installed inside the rotating drum to dry the material. However, this method has little effect on muddy materials, and undried Daikai products may be produced due to rolling granulation in the drum, and sometimes cause clogging.

In addition, in order to increase the processing capacity of heating with hot air, it is necessary to increase the wind speed of the ventilation flow, which causes significant scattering of materials and requires a large investment in exhaust gas treatment.

In addition, energy recovery from exhaust air is extremely expensive and is not generally performed.

In heating using hot air, the thermal efficiency is about 30 to 60%.

From this point of view, it is desirable to adopt a system in which the latent heat of vaporization is applied by conduction heating and the generated steam is removed from the system by ventilation, and the amount of exhaust gas is controlled as much as possible to remove the generated steam.

In drying using this conduction heating method, it is essential to increase the heat-receiving area of the material. Conventionally, this method involves stirring the material with a stirring blade and making the inside of the stirring blade hollow to allow the heat medium to pass through. ing.

However, in this method, the material must flow within the interval between the stirring blades, so the pitch cannot be made very small, and the heat receiving area is limited.

Further, the path through which the heat medium passes must be designed so that the heat medium does not stagnate within the path, and for this reason, it is difficult to allow the heat medium to pass through the entire heat transfer surface of the blade.

This idea was made in order to eliminate the above-mentioned difficulties in drying muddy materials. By sprinkling muddy materials onto magnetic material balls, or steel balls, the heat transfer surface was dramatically increased. Our aim is to provide a device that heats a steel ball by induction heating and heats and dries muddy materials.

An embodiment of this invention will be described below with reference to the drawings.

In the figure, 1 is a rotating drum, 2 is an induction heating coil wound closely around the rotating drum, and 3 is a steel ball made of magnetic material.

4 is the artificial hood of the drum, and here is the steel ball insertion hopper 5.
A slurry material input port 6 and an air supply port 7 are installed.

A steel ball outlet 9 and a dry exhaust gas outlet 10 are attached to the outlet hood 8.

To explain the drying operation of this device based on the above configuration,
The steel balls introduced are covered with sludge in the inlet hood and moved into the rotating drum.

Inside the rotating drum, the steel balls exist in a magnetic field created by an induction coil around the outer periphery of the drum, and as a result, an induced current is generated on each surface of the steel balls, which generates heat due to dicol heat.

In addition, the steel balls move freely within the drum while colliding with each other under the rotational force of the drum.

In this way, the steel balls generate heat uniformly within the drum, and the water vapor generated from the gaps created during movement is quickly transferred to the air supplied from the vent of the artificial hood and exhausted from the exhaust port of the exit hood.

The rotating drum is slightly inclined towards the outlet than the inlet, so the steel balls gradually move to the outlet hood with rotational movement,
It is taken out of the machine from the outlet of the exit hood.

The steel ball with the dried material taken out of the machine is removed by appropriate means.
It is separated from the dried sludge, for example by rotating brushes or vibrating screens.

As explained above, the device according to this invention is capable of supplying uniform and relatively instantaneous heat due to the characteristics of induction heating, and is a drying device that minimizes the amount of exhaust gas, which is a characteristic of conduction heating.

[Brief explanation of the drawing]

The drawing is a sectional view showing an embodiment of the slurry material drying apparatus of this invention. In the figure, 1 is a rotating drum, 2 is an induction heating coil, 3 is a magnetic steel ball, and 6 is a slurry material input port.

Claims (1)

[Scope of utility model registration request] A rotating drum into which magnetic material spheres sprinkled with mud material can be continuously loaded from one end and discharged from the other end, an induction heating coil wound closely around the rotating drum, and an air supply into the rotating drum. and a drying exhaust gas outlet from the drum.