DD200133A1 - DEVICE FOR ANAEROBIC TREATMENT OF SLEEP AND EQUIPMENT - Google Patents

Abstract

The invention finds application in the continuous anaerobic treatment of slurries and effluents, which have a high content of organic substances, such as in intensive livestock breeding. The invention is particularly suitable for heavily loaded Schlaemme and wastewater. The object of the invention is to provide a device in which a one- or two-stage anaerobic degradation can be performed with high intensity, wherein the heat losses and the temperature differences are to be minimized by a compact design. The inventive device consists of a cylindrical container having a reaction space for carrying out the methane fermentation and a separation chamber, where separation effects are used by sedimentation and flotation. By appropriate arrangement of Durchtrittsoeffnungen in the lower part of the reaction chamber and the separation chamber from each other separating wall Schlammrueckfuehrung is made possible in the reaction space and avoided unwanted circulation of the liquid. The reaction space and the separation chamber have a common overlying gas collection space. From a sludge collection room in the lower part of the Trenkammer thickened sludge can be removed. Fig. 1

Description

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Title of the invention

Apparatus for the anaerobic treatment of sludge and waste water

field of use

The invention finds application in the continuous anaerobic treatment of sludges and effluents with a high proportion of organic substances, such as those incurred in intensive animal breeding.

Characteristic of the known technical solutions

Numerous devices for the anaerobic treatment of sludge and wastewater are already known. The classic one-stage anaerobic sludge treatment devices require long residence times of 20 days and more in continuous operation.

This requires large reaction spaces "In order to reduce them, two-stage processes were used in which acid fermentation and methane fermentation are carried out in spatially separated reaction spaces."

Spatially separated reaction scavengers, as described in DE OS 2621524 !, have u.a. the disadvantage of the greater expenditure on equipment

Also known is a USB reactor (Lettinga a, Biotechn, Engng · 22/1980 p. 699/734) W, which is designed as a vertically flowing sludge mirror reactor and so slowly

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is traversed "that eich sets in the upper part of a solids-free or · low-solids liquid layer. This reactor has the disadvantage that the reactor contents are not homogenized.

In DE AS 2728585 a device for 'anaerobic purification of wastewater is further described and illustrated' which has a digester and a partly arranged in this over the upper liquid level Nachklärkammer for separating mud and water «

This device works by settling the sludge at the bottom of the secondary sedimentation chamber and automatically via an outlet opening, which is located at the level of the lower liquid level and lower than the inlet opening for the water-sludge mixture, automatically due to the gravity of the thickened sludge is attributed to the reaction

In this device inlet and outlet ports are spatially separated.

This device has the following disadvantages! The reaction space and the separation space have different liquid levels due to the arrangement of the outlets. Thus, the gas pressures over these liquid levels are also different.

Any disturbance in the gas pressure control thus causes a malfunction of the operation of the thickener ·

Furthermore, due to the spatial separation of the inlet opening for the mixture of liquid and sludge and the outlet opening for thickened sludge and the circulation thereby caused in the process space, undesirable flow effects occur.

Oberechußschlamm or inert solids remain inside the device.

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Object of the invention

The aim of the invention is ¹ to work up anaerobically also heavily loaded sludges and wastewater with low equipment expenditure and high intensity, with a shortening of the residence times and a high gas yield being achieved.

DISCLOSURE OF THE NATURE OF THE INVENTION Object of the invention

The invention has for its object to develop a device for anaerobic treatment of sludge and wastewater, which is' designed so that heat losses and temperature differences are largely avoided by a compact design, such flow conditions exist within the device that the residence time of the liquid is shorter than that of the solid constituents and, moreover, a deduction of the bottom slab and the inert solids is possible.

Features of the invention

The object is achieved in that the reaction chamber located in a container for methane fermentation and the separation chamber have a common Gassammeiraum and a common trigger for the resulting in the reaction chamber and in the 'separating chamber methane gas. The wall separating the reaction space and the separation chamber has in its lower part a plurality of passage openings distributed around the circumference, through which the laden liquid from the reaction space into the separation chamber and a portion of the thickened solid from the separation chamber again enters the reaction space through the same passage opening. These passage openings are arranged to each other at the same height from the bottom of the separation chamber.

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There is an accumulation chamber for thickened sludge under the openings. "The collection room is bounded by the bottom of the separation chamber, where there is also a drainage line for the thickened sludge.

The size of the passage openings is dimensioned such that the area of all openings is equal to or greater than the horizontal cross section of the separation chamber. The passages have stream breaker-like, in the interior of the separation chamber reaching baffles. These prevent the backmixing ^{t of} the laden liquid flowing into the separation chamber with the contents of the reaction space. They also serve for turbulence damping in the lower part of the Trennkaramer. Inside the separation chamber are one or more Gasleiteinrichtungen.

Between the reaction chamber and the separation chamber from each other separating wall and the container wall is the reaction chamber for methane fermentation. The separation chamber is 'centric', preferably arranged in a circle.

The separation chamber can also be in circular ring form between the wall separating the reaction space and the separation chamber and the container wall.

The partition may also be arranged in segmental form between the wall separating the reaction space and the separation chamber and the container wall.

Depending on the degradation behavior of the wastewater, a second reaction space for the acid fermentation in the container can be arranged either below the collecting space for the thickened sludge or above the common Gassammeiraumes.

It is possible, with little expenditure on apparatus, the amount of liquid from the reaction chamber of acid fermentation in accordance with the throughput together with the resulting gas in this reaction traction gas by a Stut-

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- lead 5 zenloch into the reaction chamber of methane fermentation.

The liquid to be treated enters the reaction space and is homogenized by means of nozzles and pump.

The nozzles are sufficiently large, so that an intensive mixing can take place.

The extraction of solids-free liquid and thickened sludge creates a flow from the reaction space into the separation chamber. This flow is superimposed on another flow, which is caused by higher density of the solid in the lower part of the separation chamber and through which, the solid-enriched liquid is reclaimed into the reaction space. In the separation chamber, the separation of the clear and thickened phase takes place.

By Gasleiteinrichtungen the gas bubbles, which arise in the separation chamber, as well as floating biomass are directed upwards. Entrained foaming liquid and biomass slides back over the upper boundary into the reaction space.

All the gas is discharged via a nozzle and low-solids liquid from the upper part of the separation chamber via an overflow *

A portion of the solidified in the separation chamber solid flows back through the through-openings in the reaction space.

The other part of the thickened solid collects in the lower part of the separation chamber, the collection space for thickened sludge, from where it is withdrawn via a discharge line continuously or discontinuously. The withdrawal amount is determined by the proportion of non-degradable solids.

As advantages of the invention are the intensive mixing in the reaction space on the one hand, the combined effect of the separation chamber ', in the utilization of Sedimen-

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JS ^l

tion and the flotation ^, on the other hand, the compact arrangement of the individual reaction chambers within a load-bearing container construction, the possible Temperaturkonstanzfi 'the low heat loss and the ability to! Introduce the gases of an upstream acid fermentation in the reaction chamber to carry out the methane fermentation ?, Consider »

Ausfuhrungsbeispie1

The invention will be explained in more detail below with reference to two embodiments.

In the accompanying drawing show

Fig. L: A schematic representation of the apparatus for the anaerobic treatment of sludge and wastewater in longitudinal section

Fig. 2: an achematic view of the device with a changed arrangement of the separation chamber in longitudinal section

The apparatus consists of a cylindrically standing container 1, which contains a reaction space 2 for carrying out acid fermentation, at which an inlet opening 3, as well as a pump with a nozzle 5 connected thereto, are present in the vicinity of the container bottom.

The resulting homogenization of the incoming laden liquid can be achieved instead of the system pump / nozzle with known stirrers «

The reaction space 2 for acid fermentation is located below another reaction space 6 for methane fermentation.

However, the reaction space 2 can also be arranged above the reaction space 6, or also in dependence

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from the degradation behavior of the sludge and the wastewater completely eliminated.

Both reaction spaces are separated by an intermediate floor 7 «

This floor has depending on the size of one to three circumferentially distributed spigot holes 8,

In order to avoid backmixing of the reaction chamber contents, the nozzle holes 8 are provided with baffles 9 in the form of a nozzle.

Above the intermediate bottom 7 there is also a pump IO with a nozzle 11 connected thereto which also homogenizes the loaded liquid entering the reaction space 6 from the reaction space 2 so as to obtain optimum physical conditions for the degradation of the sludge and the wastewater.

In the reaction chamber 6 of the methane fermentation is a coaxially arranged cylindrical separation chamber 12, which preferably has centrally arranged in its interior Gasleiteinrichtungen 13.

In this case, a gas-conducting device or a plurality of gas-conducting devices 13 can be arranged one above the other.

The upper boundary of the separation chamber 12 has a gas outlet opening 14 and an overflow 15, flows back from the flooded biomass with foam in the reaction chamber 6.

In the lower part of the reaction chamber and the separation chamber separating wall 17 a plurality of passage openings 16 are present.

These passage openings 16 are preferably at the same height to each other, at a distance from the intermediate bottom 7, which is one to two times the diameter of the separation chamber 12, respectively.

The area of all openings shall be such that they are equal to or greater than the horizontal transverse

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Sectional surface of the separation chamber 12 is. The passage openings 16 are equipped with baffle-like guide plates 18.

Below the passage openings 18 is a collecting space 19 for thickened sludge.

The intermediate bottom .7, which simultaneously represents the bottom of the separation chamber 12 and thus the bottom of the collecting space 19, has a discharge line 20 for the thickened sludge.

In the reaction chamber 6 is located immediately below the liquid level, a discharge device 21 for emerging scum.

For the derivation of low-solids or solids-free liquid, a pipe 22 is provided, which is a connection to the upper part of the separation chamber 12 and a stand container 23 located outside the container 1.

In the separation chamber 12 and in the reaction chamber 6, an equally high liquid level is present, which is partially interrupted by the upper separation chamber boundary. Above the liquid level there is a common gas collecting space 24, which is delimited by the container wall. On top of this, a gas outlet pipe 25 is attached at the top.

The design of the device ensures a good separation in the clear and thickened phase and allows a high biogas yield.

The device according to the invention works as follows:

Through the inlet opening 3, the wastewater to be treated enters the reaction space 2. The wastewater must be limited in the solids content so that a pumpable consistency is formed. Solid constituents above 10 mm particle size should, before entering the

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direction to be separated «

In the reaction chamber 2, the loaded liquid is homogenized by the pump 4 and the connected nozzle 5.

If the reaction space 2 is completely filled, it is under the hydrostatic pressure of the entire liquid column.

A liquid gas mixture is forced through the nozzle holes 8 into the reaction space 6 in accordance with the charged liquid supplied through the inlet opening and the amount of digester gas which arises in the process.

The resulting biogas exerts a pump action on this loaded fluid by its upward movement to assist the flow of the liquid gas mixture.

In the reaction space 6, a further homogenization of the liquid gas mixture takes place, which is effected by the pump IO and the connected nozzle 11.

Approximately the same amount of liquid as added through the inlet opening 3 passes through the passage openings 16 from the reaction space 6 into the separation chamber 12, in the separation chamber takes place at cross-sectional loads

3 2

of ca, l m / m h a separation of the liquid gas mixture in clear and thickened phase, in flotation foam and gas. In this case, a biomass concentration is reached in the separation chamber, which is greater than that of the reaction chamber 6.

Floated biomass rises as flotation foam together with emerging methane gas through the gas guide 13 upwards, wherein the gas enters the gas collection chamber 24 and is discharged from there via the gas outlet pipe 25. Flotation foam enters the reaction chamber 6 via the upper boundary via the upper run 15. This recirculation can be assisted by a liquid jet.

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Low-solids or solids-free liquid is passed from the separation chamber via a pipe 22 into the stand tank 23.

The thickened sludge falls due to the principle of gravity in the lower part of the separation chamber, the plenum 19 and is withdrawn on the one hand continuously or discontinuously via a discharge line 20 to the outside. The deduction amount is determined by the amount of excess sludge and by the proportion of non-degradable solids.

On the other hand, thickened solid flows out of the collecting space 19 through the passage openings 16 'into the reaction space 6.

FIG. 2 shows a further embodiment of the device with a modified separation chamber arrangement. It is preferably applicable to poorly sedimenting sludges and short degradation times.

This embodiment differs from that of FIG. 1 by the arrangement and design of the separation chamber as a function of the reaction space 6 of the methane fermentation,

The design of the separation chamber 12 depends on certain parameters, which can be determined according to the following formula:

Reference number =

ⁿ o

W_ means the maximum possible up-

speed in the separation chamber

t, the mean residence time in the methane fermentation space

h _Q the height of the reaction chamber of the methane fermentation

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If the code number is smaller than 1, preferably annular separation chambers are used, as shown in FIG. 2.

If the ratio is greater than 5, preferably centrically arranged circular separation chambers, as shown in Fig, I, are used.

If the value of the code is in the range l ··· 5, segmented separation chambers can be used _e

The wall separating the reaction chamber and the separation chamber from each other represents a chord.

The apparatus according to FIG. 2 includes two reaction spaces in a cylindrically standing container 1,

The reaction chamber 2 for acid fermentation is located under the reaction chamber 6 for the methane fermentation, both spaces are separated by an intermediate bottom 7.

For the passage of the liquid gas mixture from the reaction chamber 2 in the reaction chamber 6 is centrally located a nozzle hole 8, which is provided with a baffle in the form of a nozzle.

For the purpose of homogenizing the liquid gas mixture, a pump 4 with a connected nozzle 5 is located in the reaction space 2.

The contents of the reaction space 6 is homogenized, for which the pump IO with the nozzle 11 are present. For separating clear and thickened phase, flotation foam and gas, a separation chamber 12 is present. This is attached to ensure a sufficient cross-sectional area of the separation chamber 12 in an annular design approximately rotationally symmetrical on the supporting shell of the container 1.

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In the interior of the separation chamber Gasleiteinrichtungen 13 are arranged one or more times one above the other.

The reaction chamber 6 and the separation chamber 12 from each other separating wall 17 has a plurality of openings 16.

They are preferably arranged at the same height to each other. These passages are provided with baffles baffles 18 which are directed radially outward and thus are located in the interior of the separation chamber 12.

A collecting space 19 for thickened sludge is located under the passage openings.

Thickened sludge can be withdrawn via a discharge line 20. Low-solids or solids-free liquid is introduced into a stand container 23 arranged outside the container 1 via a pipeline 22.

For discharging floating scum, there is a take-off device 21 in the form of two opposing vertical walls separating a part of the annular separation chamber. By diametrically arranged nozzles · the floating sludge discharge is supported «The separation chamber 12 and the reaction chamber 6 have equal liquid levels.

Above the liquid level is a common Gassam melraum 24. The entire gas is discharged from the gas collection chamber via a gas outlet nozzle.

With both embodiments, all anaerobic degradable sludge and wastewater can be treated, wherein the degradable organic dry matter should preferably be greater than 5000 - 8000 g / m ³ .

These include, above all, the by-products of intensive animal breeding, but also upper sludge from aerobic sewage treatment plants.

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Treatment equipment · The residence time of the liquid is between 1 and 6 days, depending on the temperature regime and the type of ingredients.

Claims (6)

233675 k invention claim 1. An apparatus for the anaerobic treatment of sludges and waste water with a high content of organic substances consisting of a provided with inlet and outlet nozzle container in which a reaction chamber for methane fermentation and a separation chamber for separating thickened sludge and liquid is arranged, characterized in that the reaction chamber (6) and the separation chamber (12) communicate with an overlying, common gas collection chamber (24), a wall (17) separating the reaction space and the separation chamber from one another has through openings (16) in its lower part Separating chamber is arranged below these passage openings a collecting space (19) for the thickened sludge and the collecting space is provided with a discharge line (20) for the thickened sludge. 2. Device according to item 1, characterized in that the area of all passage openings is equal to or greater than the horizontal cross-sectional area of the separation chamber · j 3 · Device according to items 1 and 2, characterized in that the passage openings are equipped with baffle-like baffles (18) · 4 · Device according to item 1, characterized in that one or more superimposed gas-conducting devices (13) are provided in the interior of the separation chamber 5t device according to item 1, characterized in that between the reaction space and the separation chamber 233675 4 mer separating wall (17) and the container wall of the reaction chamber for methane fermentation (6) is located. 6. Device according to point l, characterized characterized. "That between the Reaktionsrautn and the separation chamber from each other separating wall (17) and the container wall, the separation chamber (12) is arranged annularly. 7. Device according to point ic, characterized in that between the reaction space and the separation chamber from each other separating wall (17) and the container wall, the separation chamber (12) is arranged segment-shaped. 8. The device according to item l to 4, characterized in that in the container below the collecting space (19) for the thickened sludge, a second reaction chamber (2) is arranged for an acid fermentation is in communication with the reaction space for methane fermentation. 9. Device according to punk / t 1 to 4, characterized in that in the container above the common gas collecting space (24), a second reaction chamber (2) for the acid fermentation is arranged, which communicates with the reaction space for the methane fermentation. For this 2 pages drawing