JPH035000A - Dehydrating and drying apparatus - Google Patents

Abstract

PURPOSE:To further reduce the moisture content of dehydrated cakes and hence the amt. thereof by coupling integrally a belt type dehydrator and a dryer fitted with far infrared irradiators as a heating source. CONSTITUTION:Condensed sludge is supplied from a mud feeder 8 into a gravitational dehydrating zone 9 so as to be dehydrated therein under the force of gravity and the removed liquid is carried out of a dehydrator through a receiving tray 10. The dehydrated sludge held between an upper and a lower filter cloth 1 and 2, as they travel upwardly, is run between pressure rolls 3 so as to be dehydrated by the shearing action thereof, separated at a drive roll part 5 from the filter cloths by a scraper 17 and dropped onto a metal mesh belt 12 through a chute 16. A dryer B is provided with far infrared irradiators 15 for irradiating the cakes dropped onto the metal mesh belt 12 with far infrared rays, whereby moisture is removed from the cakes by evaporation to dry them. Such irradiation is continued through a series of irradiators from the uppermost down to the lowermost one to dry the cakes to a desired water content and the cakes, irradiated by the lowermost irradiator, are discharged from the unloading end of the metal mesh belt 12 to the outside of the dryer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of a belt-type dehydrator used for dewatering sludge and the like.

[Conventional technology]

As a conventional belt-type dehydrator of this type, there is a dehydrator generally called a belt press. This belt press dehydrates concentrated sewage sludge or the like by gravity to eliminate its fluidity, and then dehydrates it under pressure using jarring rolls or press rolls. Special Publication No. 64-4878 is an example of this.
This type of mechanical pressure operation has a limit to its dehydration, and the moisture content of the cake obtained with this type of dehydrator is 7.
It is about 5%. In order to further lower this water content, there are methods such as heating the cake during dehydration as in Utility Model Application No. 59-180895, and methods as in JP-A-56-60604.
There are methods that apply electroosmotic treatment to sludge during pressure dewatering, and methods that use metal mesh belts to squeeze the sludge that has been pressure dehydrated, but even with these methods, it is not possible to significantly reduce the water content. I haven't been able to do it.

[Problem that the invention seeks to solve]

Traditionally, belt-type dehydrators are vacuum-type dehydrators and long-range dehydrators.

Compared to the 85% or so of the dehydrated cake of the heart-separated dehydrator, it is advantageous because it can greatly reduce the moisture content of the dehydrated cake to around 75%, but it is inferior to the 70% or less of the filter press. There are drawbacks such as insufficient weight loss when disposing of the cake after the fact. For this reason, in order to further reduce the moisture content of the dehydrated cake and reduce its weight, the above-mentioned methods such as heating are used, but in reality, even with these methods, the desired results cannot be obtained.

[Means for solving problems]

This invention uses a means different from the conventional concept of filtration and dehydration to reduce the moisture content of the dehydrated cake of the belt-type dehydrator as described above, and its gist includes many points. A belt-type dehydrator is constructed in which a pair of upper and lower filter cloths are freely runnable between parallel pressure rolls, and the sludge, etc. held by the upper and lower filter cloths is pressurized and dehydrated. A dryer equipped with multiple metal mesh belts for conveying the material to be dried is installed on the filter dregs discharge side of the dryer, and the starting end of the metal mesh belt of this dryer is connected to the p of the belt-type dehydrator.
A far-infrared radiator that can radiate far-infrared rays to the P slag on the metal mesh belt is disposed facing the slag discharge section and above the metal mesh belt.

[Effect]

This invention is configured as described above, that is,
This device uses a drying device that uses far infrared rays in place of the conventional heating device and mesh belt for squeezing.In particular, the filter dregs discharged from the belt type dehydrator are dehydrated to a thin thickness, so far infrared rays are absorbed internally. It is possible to allow sufficient permeation until the point of contact, allowing the contained moisture to evaporate and drying efficiently.

However, since the metal mesh belt is provided in multiple stages and far infrared rays can be radiated to each stage of the metal mesh belt, the moisture content of the dried P slag can be easily controlled.

In other words, if you want to obtain P slag with a lower water content, even if you increase the irradiation intensity of the far infrared rays, the thickness of the trout slag may be thinned so that the far infrared rays can penetrate deep into the crab slag. is also possible. In addition, although the far infrared rays irradiated in this way are radiation, they are irradiated directly onto the P slag, so there is no loss and it is more efficient than heating through conventional rolls or filter cloth. .

Hereinafter, this invention will be specifically explained based on the drawings.

〔Example〕

In the figure, symbol A is a belt type dehydrator, and B is a dryer connected to the belt type dehydrator and uses far infrared rays as a heating source. The belt type dehydrator is configured as follows. Reference numeral 1 denotes a lower filter cloth, and 2 denotes an upper furnace cloth, which are freely runnable between a large number of pressure rolls 3 and guide qles 4 arranged in parallel. Reference numeral 5 is an E-movement roll for the filter cloth, 6 is a drive motor, 7 is a tension roll for the upper furnace cloth 2 and lower filter cloth 1, 8 is a slurry feeder, 9 is a gravity dewatering zone, and 10 is a gravity dewaterer. A receiver for P liquid in the zone, 11 is a receiver for P liquid in the pressurizing zone.

Next, the configuration of dryer B will be explained. Reference numeral 12 indicates a metal mesh belt arranged in multiple stages vertically, 13 indicates a drive motor thereof, 14 indicates a drive chain, 15 indicates a far-infrared ray radiator provided above the metal mesh belt 12, 16 indicates a chute, and 17 indicates a cake peeling device. It's a scraper.

In the dehydration dryer configured in this way, concentrated sludge is supplied from the sludge feeder 8 to the gravity dewatering zone 9, where it is gravity dehydrated, and the P liquid is taken out of the machine via the saucer 10. As the furnace cloth 1.2 runs, the gravity-dehydrated sludge rises between the pressure rolls 3 while being held between the upper and lower filter cloths 1.2, and is subjected to a jarring action by the pressure rolls 3 and dehydrated. The filter cloth 1.2 is peeled off by the scraper 17 in the drive roll 5 section, and falls onto the metal mesh belt 12 by the chute 16. Returns to the dewatering zone and sludge is supplied.

In dryer B, the metal mesh shell that fell first)
The cake on top of No. 12 is irradiated with far-infrared 11 Ad; this irradiation evaporates and dries the moisture inside the cake, and this irradiation is continued until the bottom layer is reached, drying it to the desired moisture content, and the metal on the bottom layer is It is taken out of the machine from the play* of the mesh belt 12. Incidentally, during the above-mentioned dehydration and drying, the belt type dehydrator A and the dryer B are sealed and do not emit any bad odor or the like to the surrounding area. Note that, although not shown in the drawings, the odor evaporated in the dryer B is taken out to the outside through a duct.

〔Effect of the invention〕

As is clear from the above explanation, the present invention has been achieved by integrally connecting a belt-type dehydrator with a dryer that uses far infrared rays as a heat source, which could not be achieved with conventional mechanical pressure means or heating means. Not only can the moisture content in the belt-type dehydrator, which could not be achieved, be significantly lowered, but the moisture content of the cake can be freely adjusted to obtain a desired moisture-containing cake. In particular, since it uses far-infrared rays for heating, compared to conventional heating means, it can be heated efficiently without being carried away by the medium, and it has excellent effects such as easy control and easy maintenance. play.

[Brief explanation of drawings]

FIG. 1 is a side view of a dehydrating dryer according to the present invention, with the side plate removed. Figure 2 is a side view of the dryer, and Figure 3 is a side view of the dryer.
Similarly, it is a front view. 1.2 Filter cloth 3 Pressure roll 5 Drive roll 12 Metal mesh belt 15 Far-infrared radiator A Belt type dehydrator B Dryer

Claims (2)

[Claims] (1) A pair of upper and lower filter cloths 1 between many parallel pressure rolls 3
, 2 are freely runnable, and the sludge, etc. held between the upper and lower filter cloths 1 and 2 is pressurized and dewatered. A dryer B is provided which is equipped with multiple stages of metal mesh belts 12 for conveying materials to be dried, and the starting end of the metal mesh belt 12 of this dryer B faces the filter dregs discharge section of the belt type dehydrator A. A dehydrating dryer characterized in that a far-infrared ray emitter 15 that can radiate far-infrared rays to the filter dregs on the metal mesh belt 12 is disposed above the metal mesh belt 12. (2) Pressure rolls 3 are arranged in parallel in the belt-type dehydrator A in multiple stages in the vertical direction, and the diameter of the pressure rolls 3 is configured to become smaller in diameter from lower to upper. The dehydrating dryer according to claim 1, wherein the roll 5 for discharging the cake of the belt type dehydrating machine A is provided above the uppermost metal mesh belt 12 of the dryer.