ES2303785B1 - PROCEDURE FOR THE VALUATION OF MUDS FROM RESIDUAL WATER TREATMENT STATIONS. - Google Patents

Abstract

Sludge recovery procedure coming from sewage treatment plants. Sludge (L) are introduced into an interior chamber (4) of a first oven (1), or muffle oven, also provided with a jacket (5) or outer chamber of air heating. The sludge is combusted in the chamber-home (4) until their merger, to obtain a material vitrified (V) that is deposited in the crucible (6) of the Household chamber (4) of the first oven. Of this one extract: vitrified material (V), towards a melting furnace (7) of glass; combustion fumes (F) of the jacket (5) or chamber Exterior; and a tail product (8), which contains part of the material organic that has not yet combusted, part of inorganic material entrained, reheated steam and hot air with gases inert Part of the inorganic materials (9, 10) of the product of tails is recirculated to the inner chamber of the first oven.

Description

Sludge recovery procedure coming from sewage treatment plants.

Technical sector of the invention

The present invention relates to a procedure for the recovery of sludge from wastewater treatment plants (WWTP), with sludge being constituted by an organic fraction, an inorganic fraction and Water.

Background of the invention

In the water treatment plants Wastewater (WWTP) treats water from processes industrial for purification and is obtained as a product resulting a more or less treated water, susceptible to different reuses, depending on your debug parameters, and about sludge or sludge that, with humidity between more than 98% and 60%, incorporate a large part of solid products from the process industrial and other substances produced during the process itself Debugging

The recovery or reuse of these sludges It is a major environmental problem. its Revaluation as compost is not always possible and its use as raw material as construction material entails normally inconveniences or technical problems of magnitude nothing negligible In the cases of certain manufacturing industries, the sewage sludge from their wastewater may have a high energy content, for whose recovery there are in the Currently a good number of systems and plants.

The present invention proposes a novel water purification sludge revaluation system residuals, which allows its contents and oxides to be revalued metallic and inorganic, on the one hand, recover much of their energy content, on the other hand, and eliminate from its content the mostly harmful or dangerous inorganic components from The environmental point of view.

Explanation of the invention.

Thus, in the present invention a new procedure for the recovery of sludge from wastewater treatment plants, which in essence are characterized by understanding the stages of:

-

sludge introduction in a interior chamber-home of a first oven -u furnace-muffle-, equipped with a shirt or outdoor air heating chamber,

-

combustion of sludge in the chamber-home until their merger, for the obtaining a vitrified material that is deposited in the crucible of the chamber-home of the first oven,

-

extraction of the first oven from:

-

vitrified material, towards an oven of glass melting;

-

the combustion fumes of the jacket or outer chamber; Y

-

a product of tails, which contains part of organic material that still has not combusted, part of entrained inorganic material, steam of reheated water and hot air with inert gases; Y

-

recirculation of part of the materials inorganic tails product to the inner chamber of the first oven or muffle oven.

According to another feature of the present invention, the introduction of sludge into the inner chamber is Produces with powdered sludge. Sludge spraying can be done by air or steam under pressure, introduced by an endless screw or by transport tire.

According to another feature of the In the present invention, the method comprises the step of introduce the outgoing tail product from the first oven into the chamber of a second subsequent furnace, and arranged in series with the  first furnace, in which the combustion of matter continues organic, and from which combustion fumes come out, which contain gases warm inert, reheated water reheated organic matter, and from which a first fraction of inorganic substance is recirculated vitreous towards the chamber-home of the first oven.

Preferably, in such case, a phase is provided to recover, in a first recuperator, part of the heat contained in the combustion fumes from the second furnace, for reheat the inlet mixture in the second oven.

In addition, the driving phase can be provided part of the heat recovered in the first recuperator at the entrance of hot air from glass melting furnace.

Preferably, the stage is provided additional to introduce the aforementioned combustion fumes of the second oven, inside a third oven, arranged in series with the second furnace, in which the combustion of matter continues organic, and from which combustion fumes come out, which contain gases warm inert, reheated water reheated organic matter, and from which a second fraction of inorganic substance is recirculated vitreous towards the chamber-home of the first oven.

In addition, there may be a recovery phase, in a second recuperator, part of the heat contained in the fumes of combustion protruding from the third oven, consisting of a clean gas-air exchanger, the air being clean heated in the second recuperator, led to the chamber-home of the first furnace-muffle, in order to preheat the combustion air of the sludge of said chamber-home.

According to another feature of the present invention, the combustion fumes of the outer chamber are filtered of the first oven, in a bag filter, and the reintroduction phase filtered inorganic components, into the Household of the first oven.

Brief description of the drawings

The attached drawings illustrate, by way of non-limiting example, an example of non-exclusive realization, of method according to the present invention, in which only Fig. shows the operating principle scheme of the process.

Detailed description of the drawings

In these drawings it can be seen that the recovery procedure by vitrification of sludge from WWTP is produced in three blocks:

1st Block

First oven or muffle oven with crucible

Start with the introduction of L sludge from WWTP, pulverized, inside a chamber-home 4 of a first furnace-muffle 1 with crucible 6-heated externally by means of a shirt 5, at elevated temperature, by means of a fuel-natural gas, gas-oil, biogas, etc.- so that heat from the wall is transmitted exterior to the interior of the chamber-home 4.

The sludges L that are introduced inside said home chamber 4 is sprayed. its spraying is done in a pre-phase or simultaneously with the introduction of sludge L in the chamber-home 4 and can be done according to three different systems:

to)

introduction with pressurized air or steam under pressure

b)

introduced by screw without - finish

C)

introduction by transport tire.

This sludge spraying process L It can be done both by being in the dry state and in dehydrated state

The combustion of sludge L in the chamber-home 4 until their merger, produces a vitrified material V that is deposited in crucible 6 of the chamber-home 4 of the first oven 1.

During your stay inside this chamber-home 4 of the first oven 1, or muffle furnace, there are also different modifications and different behaviors of the components organic and inorganic sludge L, specifically:

one)

Water becomes superheated steam

2)

Organic substances partially combustion or totally generating heat

3)

Unburned gases travel through the container to its exit

4)

The inorganic elements remain:

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a part deposited as vitrified material V in the bottom or crucible 6, another one on the walls of the chamber-home 4; Y

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the rest leaves through an exit opening of the unburned gases and entrained particles that have not been deposited in chamber 4.

Subsequently, the extraction of the first furnace 1 of the vitrified material V, which is fed to a 7 glass melting furnace.

Combustion fumes F of jacket 5 or outer chamber exit to an exchanger 20, for the pre-heating of air driven by a fan 19. F fumes continue, with the help of an extractor 21, to a bag filter 16, where they are filtered, producing inorganic vitreous components 17, which are reintroduced into chamber-home 4 of the first oven one.

From the oven 1 comes a product of tails 8, towards a second oven 2, which contains part of organic material that still has not combusted, part of entrained inorganic material, steam of reheated water and hot air with inert gases.

In oven 1 it is reintroduced, as explained later, part of the inorganic materials 9, 10, of vitreous nature of the product of tails 8.

2nd Block

Oven 2

Inert gases generated by combustion of the organic material deposited in the chamber-home 6 of the first oven 1, are transferred to the Household of a second oven 2 together with:

to)

The remaining organic substances which have not yet finished the combustion

b)

He dragged inorganic material and

C)

He reheated water vapor.

In this second oven 2, through a system 12 heat recovery ceramic that has been introduced in she recovers the heat that comes off, in part, through the fumes 12 and, in part, through the walls of the chamber and that It is generated by:

to)

The combustion of the remaining organic matter from the first chamber already moved to this second

b)

He reheated steam

C)

The inorganic matter dragged from the first chamber and

d)

He heat of inert gases.

This part of the heat that is recovered has as purpose of heating the air that enters the second chamber oven 2 to end the combustion combustion process leaving the first chamber of the first oven 1 through the indicated product of tails 8.

From the second oven 2 a first is extracted fraction of vitreous inorganic substance 9 that is introduced into the chamber-home 4 of the first oven 1.

The air that heats the recuperator 12 can be to the outgoing air of the exchanger 20, and part of the outgoing air of the recuperator 12 can be directed towards the pre-heating of input 8, and part being driven to the hot air inlet of the melting furnace of glass 7.

3rd Block

Oven 3

The fumes 11 protruding from the second oven 2 they contain:

to)

The hot inert gases

b)

He reheated water and

C)

The heated inorganic matter.

These fumes 11 are introduced inside of a third oven 3, arranged in series with the second oven 2, in that the combustion of organic matter continues, and from which combustion fumes 13, containing inert gases hot, reheated water reheated organic matter, and from which a second fraction 10 of vitreous inorganic substance is recirculated towards the chamber-home 4 of the first oven 1.

In a second recuperator 14, part is recovered of the heat contained in the combustion fumes 13 projections of the third oven 3. It is an exchanger clean gas-air, from which the clean air comes out heated 22 towards the first chamber-home 4 muffle furnace 1, with a view to preheat combustion air 15 of sludge L of said chamber-home 4.

Also, to a camera attached to the Household of the third oven 3, have arrived:

to)

Gas inert that have already given off some of the heat

b)

Steam

C)

The inorganic materials remaining.

All of which is debugged by different equipment:

to/

A sleeve filter, to collect inorganic components

b /

A inert gas filter

C/

A water vapor condenser.

The rest of inert gases, already filtered, pass to the atmosphere.

The installation can be complemented with a water vapor condenser.

Finally, the extraction of virio V deposited in bottom or crucible 6, towards melting furnace 7 of glass 7 cited above. N the oven 7, in addition to the substance glass from oven 1, other materials are introduced complementary 18, such as different oxides components of the glass, in different proportions, customer air from the recuperator 12, and combustion fumes emerge 23.

The glass produced in the melting furnace 7 will leave the same, for example towards the machines of conformation of glass items, either hollow or flat.

The reheated air in the exchanger 12 and the excess fumes F and 23 can be used in other processes to melt more glass, to generate electric current, in industrial thermal processes, etc.

Describe sufficiently the nature of the The present invention, as well as how to implement it, is states that everything that does not alter, change or modify its fundamental principle, is subject to variations in detail.

Claims (11)

1. Procedure for the recovery of sludge (L) from wastewater treatment plants (WWTP), the sludge consisting of an organic fraction, an inorganic fraction and water, characterized in that the procedure comprises the steps of:

-

sludge introduction in a interior chamber (4) of a first oven (1), or muffle furnace, also equipped with a shirt (5) or outdoor air heating chamber,

-

sludge combustion (L) in the chamber-home (4) until their merger, to obtain a vitrified material (V) that is deposited in the crucible (6) of the chamber-home (4) of the first oven (1),

-

first oven extraction (1) from:

-

vitrified material (V), towards an oven melting (7) glass;

-

the combustion fumes (F) of the jacket (5) or outer chamber; Y

-

a glue product (8), which contains part of organic material that has not yet combusted, part of dragged inorganic material, superheated steam and hot air with inert gases; Y

-

recirculation of part of the materials inorganic (9, 10) of the product of tails to the inner chamber of the First oven (1) or muffle oven.

2. Method according to claim 1, characterized in that the introduction of the sludge into the inner chamber occurs with the pulverized sludge. 3. Method according to claim 2, characterized in that the spraying of the sludge is carried out by means of air or steam under pressure. 4. Method according to claim 2, characterized in that the sludge is introduced by means of an endless screw. 5. Method according to claim 2, characterized in that the sludge is introduced by pneumatic transport. Method according to claim 1, characterized in that it comprises the step of introducing the product of tails (8) protruding from the first furnace (1), into the chamber of a subsequent second furnace (2), and arranged in series with the first furnace (1), in which the combustion of organic matter is continued, and from which combustion fumes (11), containing hot inert gases, reheated water, reheated organic matter, and from which a first fraction of inorganic substance is recycled ( 9) vitreous towards the chamber-home (4) of the first oven (1). Method according to claim 6, characterized in that it comprises a phase of recovering, in a first recuperator (12), part of the heat contained in the combustion fumes (11) protruding from the second furnace (2), to reheat the inlet mixture (8) in the second oven. Method according to claim 7, characterized in that it comprises the phase of driving part of the heat recovered in the first recuperator (12) to the hot air inlet of the glass melting furnace (7). Method according to claim 6, characterized in that it comprises the step of introducing said combustion fumes (11) of the second furnace (2), inside a third furnace (3), arranged in series with the second furnace (2) ), in which the combustion of organic matter is continued, and from which combustion fumes (13), containing hot inert gases, reheated water, reheated organic matter, and from which a second fraction (10) of inorganic substance is recirculated vitreous towards the chamber-home (4) of the first oven (1). Method according to claim 9, characterized in that it comprises a phase of recovering, in a second recuperator (14), part of the heat contained in the combustion fumes (13) protruding from the third furnace (3), consisting of a gas exchanger clean air, the clean air being heated in the second recuperator, taken to the home chamber (4) of the first furnace-muffle (1), in order to preheat the combustion air (15) of the sludge (L) of said Household camera Method according to claim 1, characterized in that it comprises the phase of filtering combustion fumes (F) of the outer chamber (5) of the first furnace (1), in a bag filter (16), and the reintroduction phase inorganic components (17) filtered, into the chamber-home (4) of the first oven (1).