DE2610510A1 - METHOD AND DEVICE FOR REMOVING ASH FROM WASTE WATER TREATMENT SYSTEMS - Google Patents

Description

Dr. F. Zumstein Sr. - Dr. E. Assmann - Dr. R. Koenigsberger Dipl -Phys. R. Holzbauer - Dipl.-Ing. F. Klir.gsciaen - Dr. F. Zumstein jun.

TELEPHONE: COLLECTIVE NO. 22 5341

TELEX 529979 TELEGRAMS: ZUMPAT

CHECK ACCOUNT: MUNICH 91139-809, BLZ 7OO1OO8O BANK ACCOUNT: BANKHAUS H. AUFHÄUSER ACCOUNT NO. 397997, BLZ 7OO 306 OO

8 MUNICH 2.

BRÄUHAUSSTRASSE 4

12 / pi

Case D.N. 4537

STERLING DRÜG INC., New York, N.Y./USA

Method and apparatus for removing ash from wastewater treatment systems

The present invention relates to a method and an apparatus for separating and removing ash from a powdered carbon waste treatment system.

In a method using the gas classification of liquid suspended solids for concentrating and removing the accumulated inert material from a wastewater treatment system With powdered activated carbon there is a tendency to remove inert non-oxidizable solids from the Carbon was captured from the sewage system and ash resulting from a slight oxidation of carbon in each regeneration cycle originate, accumulate in a closed solid system if no measures are taken, inert Remove solids. One method of removing inert solids is to continuously remove some of the consumed or to discard regenerated carbon stream, which, however, leads to a considerable loss of carbon and too leads to the problem of increased solids removal.

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The aim of the present invention is to reduce carbon losses as well as reducing the amount of solids to be discarded before they are removed from the system.

According to the invention a method for separating and removing ash from a system for wastewater treatment with pulverized Carbon created, which consists in flowing the sewage in contact with powdered carbon to let, thereby purifying the water, directing the purified water to a settling tank from which the clear produced Water is withdrawn while the solids sink to the bottom, giving pressure to the from the bottom of the settling tank in the form of a pressure Slurry withdrawn. Solids apply to the slurry to heat in a heat exchanger, to feed the slurry from the bottom into a reactor in which the carbon is regenerated by wet air oxidation and a classification or sorting of the solids by the turbulence of the Slurry under pressure, as it ascends into the reactor, causing the heavier solids, including the Ash in the quay of the bottom of the reactor is withdrawn and the lighter regenerated carbon slurry at the top of the reactor is withdrawn and then reintroduced into the inflow.

In general, in practicing the invention, incoming wastewater from any purification system will be pulverized Carbon brought into contact, wherein the carbon adsorbs organic material. The method further includes Purification of the water which is then allowed to settle and the removal of carbon and the organic adsorbed Materials that provide a clear, purified water product which, of course, is withdrawn. The sedimentation process of solids in the de-icing flow are continuously recycled to the "inflowing wastewater in order to maintain a high carbon concentration in the contact zone.

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to keep. Consumed carbon is considered from the system small side stream withdrawn; this used carbon is passed through a regeneration unit. The carbon slurry is heated in a heat exchanger and then passed through a reactor, where it passes through the Entering the bottom of the reactor. The vertical reactor is long and thin with a height to diameter ratio that is Exceeds 5: 1. The carbon is regenerated in the reactor. The regenerated carbon slurry is then cooled and the cooled mixture is through a pressure-controlled valve or the like together with the Inflow brought directly back into contact with the system. The slurry (ash) is withdrawn from the bottom of the reactor and the regenerated slurry (carbon) exits the top of the reactor and that of the top Regenerated slurry exiting the end of the reactor is optionally returned to the inlet stream. This device Arrangement and this process reduce the carbon loss and the amount of solids to be discarded, the heavier inert solids (ash) being concentrated at the bottom of the reactor and from the lighter activated carbon can be separated at the top of the reactor.

In the following the invention will be described with reference to the attached Figures explained:

FIG. 1 represents a flow diagram and FIG. 2 illustrates the reactor or the reaction vessel.

One embodiment of the present invention comprises a method that is part of any overall treatment system for Wastewater forms using powdered activated carbon and carbon regeneration, for example by wet air oxidation. The flow sheet of Figure 1 sets Example of a typical system in which the subject

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of the present invention can be applied. Incoming wastewater enters an aeration tank 10 at 12; this Tank contains or is filled with powdered carbon that adsorbs organic matter and purifies the water, which is then passed into a settling tank 14 via line 16; the purified clear water obtained is in near the top of the settling tank 14, such as at 18, deducted.

Solids that sink to the bottom of the sedimentation tank are drawn off at the bottom via 20 and some of the carbon consumed is fed back to inflow 12 directly through branch line 22 in the form of a slurry. Through this a high carbon concentration remains in the container 10.

However, some of the spent carbon slurry is diverted through line 24 and this slurry becomes under pressure with wet air, compressed air obtained from the compressor 28 combined and the spent carbon slurry and the air combine in line 30 which leads to the heat exchanger of conventional construction generally represented by 32.

This mixture is then passed via line 36 through a reaction vessel 34. This reactor is shown in FIG shown. The mixture enters at the bottom of the reactor or at the bottom of the reactor, which is long, thin and vertical and its height to diameter ratio is preferably greater than 5: 1.

Both the liquid and air are introduced into the bottom of the reactor via 36, and the resulting fluid (Liquid plus gas) produces the desired effect, since the flow rate of the liquid is not sufficient to

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to generate an upward speed that can achieve classification of the pesticides. The upward flow of air in the reactor is both larger in volume and lower in density than that Liquid and leads to a considerable classification or sorting of the solids in the reactor, due to the turbulence, which it generates when passing through the vessel.

The sorting of the solids results in a slurry which sinks to the bottom of the vessel and which at exit 38 is withdrawn where the resulting high percentage of suspended solids and inert ash is withdrawn while the regenerated slurry that is forced into entering tube 40 and exiting at 42, a substantially lower inert ash content and one has a greater content of carbon solids. This (Carbon) material then becomes a heat exchanger returned where it is cooled and then through a line 44 is returned to the inflow 12.

example

In carrying out the process of the present invention, it has been found that it is possible to withdraw the slurry from the bottom of the reaction vessel with suspended solids containing an average of 80 $ inert ash and 20 $ carbon solids, whereas the regenerated slurry obtained from the top of the reaction vessel at 40 is subtracted, has an average of $ 40> inert ash and $ 60 carbon. It can therefore be seen that the ash in the return stream to inlet 12 is greatly reduced and the carbon solids increase.

one assumes that every fluid (liquid or gas) has one occupies empty reactor, the respective flow velocities were such that the average flow

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Speed upwards between 5 ″ and 10.36 cm per minute (0.17 "to 0.34 feet per minute) for the liquid and between Were 1 to 2 feet per minute (30.48 and 60.96 cm per minute) for the gas. In the practical implementation will be the two fluids are introduced into the reactor together and it is found that the actual upward velocity of the Gas is significantly higher than that calculated on the basis of the empty reactor, since its lower density causes its rise through the reactor at a much greater rate than that of the liquid. The ratio of the density of the gas to the liquid averaged 120: 1 found.

Both the device according to the invention and the one according to the invention Processes are applicable to carbon used in any part of the wastewater treatment system not only during ventilation operations, but also in the absence of air or oxygen (anaerobic), including denitrification systems.

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Claims (10)

Claims Process for separating and removing ash from a wastewater treatment system using powdered carbon by flowing the waste water into contact with powdered carbon, thereby purifying and directing the water of the purified water to a settling tank, from which the received clear water is drawn off while the solids settle to the bottom, characterized in that one is on the settled solids being withdrawn from the bottom of the settling tank in the form of a slurry that applies pressure Slurry is heated in a heat exchanger, which directs the slurry to the bottom of a reaction vessel in which the Carbon is regenerated by wet air oxidation and a classification or sorting of the solids in the reactor by the turbulence the slurry creates under pressure as it ascends through the reactor, with the heavier solids including the ash near the bottom of the reactor and the lighter regenerated carbon slurry withdrawn from the upper part of the reactor and then reintroduced into the inflow. 2. The method according to claim 1, characterized in that the outlet from the bottom of the settling tank is divided into two branches and one part is sent back to the inflow for regeneration and the other directly. 3. The method according to claim 1 or 2, characterized in that the withdrawn heavier solids more ash than Contain carbon. 4. The method according to claim 3, characterized in that the ash to carbon ratio is about 80 # inert ash or above to about 20 $ carbon or below 60984 1/0862 5. The method according to any one of claims 1 to 4, characterized in that that the lighter regenerated carbon slurry has more carbon than ash contains. 6. The method according to claim 5, characterized in that the ratio of ash to carbon is about 40 $ or ash less to about $ 60 carbon pesticides or above . 7. The method according to any one of claims 1 to 6, characterized in, that in applying pressure to the pests, air under pressure is used. 8. Apparatus for separating and removing ash from a wastewater treatment system with powdered carbon, the one container of the powdered carbon, means for creating an inflow of Waste water in the container and a line for transferring purified water from the container to a settling tank, the receives the purified water and from which the water obtained is withdrawn, comprises, characterized by a line (20) to draw off the settled pesticides into a? Slurry from the bottom of the sedimentation tank (14) including the spent carbon, a heat exchanger (32) and facilities (28) to force the slurry through the heat exchanger (32), a reaction vessel (34) and a conduit (36) to pass the heated slurry from the heat exchanger (32) into the reaction vessel (34) at the bottom thereof, wherein this reaction vessel is relatively long and narrow and has an outlet (38) for the inert ash, near the bottom of the Reactor and an outlet (40) for the gas and slurry mixture and regenerated carbon nearby of the upper part of the reactor, and means (44) for conducting this gas and the slurry and the regulated 609841/0862 nerated carbon from the reactor back to the feed stream (12) includes. 9. Apparatus according to claim 8, characterized in that the means (28) to the slurry through the To force heat exchangers (32) are capable of creating air under pressure. 10. Apparatus according to claim 8 or 9, characterized in that the line (20) from the settling tank into two branches is divided, of which a first branch (24) leads to the heat exchanger (32) and the reactor (34) and a second branch (22) directly to the feed stream (12), which is at the carbon contact "container (10) is located, leads. 609841/0862 AO Blank page