DE102019118348A1 - Neutralization system - Google Patents

Abstract

A neutralization system, comprising a reaction container (3) for receiving a liquid (F) to be neutralized and a metering device (21) with which the liquid (F) can be supplied with reaction medium for neutralization, is compact and compact with regard to the task specify a space-saving neutralization system with which an amount of liquid can be neutralized as quickly and reliably as possible, characterized in that the neutralization system comprises a measuring device (4) into which a partial amount (T) of the liquid (F) to be neutralized can be introduced, with the measuring device ( 4) the partial amount (T) for determining a required total amount of reaction medium can be at least partially or completely neutralized.

Description

The invention relates to a neutralization system according to the preamble of claim 1.

From the EP 0 567 838 B1 a neutralization system is already known. Neutralization systems are used to treat liquids so that they can be discharged as wastewater into a public sewer system.

A neutralization system of the type FRIDURIT C100 from Friatec GmbH is known from the prior art. The known neutralization plant makes use of the principle of batch neutralization. Here, a reaction vessel is filled with a liquid to be neutralized up to a maximum fill level. The liquid is then mixed in order to homogenize it. The pH of the mixed liquid is determined and compared with a neutral range.

Depending on the deviation of the pH from the neutral range, a reaction medium, namely a base or acid, is metered in in proportion to the amount of the liquid to be neutralized.

The metering takes place via a pulse width modulated opening of a metering solenoid valve. If the neutral range is maintained or measured for a predeterminable time, the neutralization system ends the neutralization and discharges the neutralized liquid into a sewer.

Such neutralization systems are used to neutralize basic or acidic liquids, i.e. to adjust their pH values as neutral as possible. The neutralized liquids can then be discharged into the wastewater, i.e. into the sewer system.

In particular, strong acids or their mixtures, for example nitric acid and sulfuric acid, also known as aqua regia, can only be neutralized with known neutralization systems with considerable expenditure of time. Under certain circumstances, neutralization can take up to two hours. This is related to the fact that a reaction medium or neutralizing medium is usually introduced into the liquid to be neutralized at a constant flow rate. It can therefore take a very long time until sufficient neutralizing medium has been added.

The invention is therefore based on the object of specifying a compact and space-saving neutralization system with which a quantity of liquid can be neutralized as quickly and reliably as possible.

The present invention achieves the aforementioned object by the features of claim 1.

According to the invention, it was first recognized that by removing a portion of the liquid to be neutralized from the reaction container, that is, by removing a suitably small sample or measurement amount, a titration can be carried out very precisely and avoiding overshoots.

It was then recognized that the amount of reaction medium required to neutralize the partial amount provides an in-situ determined basis for a suitable scaling of the neutralization process.

Knowing the amount of reaction medium that is necessary to neutralize the smaller partial amount, an extrapolation can be carried out in a simple manner in order to determine the amount of reaction medium which is necessary to neutralize the further liquid in the reaction vessel that has yet to be neutralized.

The neutralization system therefore comprises a measuring device into which the partial amount of the liquid to be neutralized can be introduced, the partial amount being able to be at least partially or completely neutralized with the measuring device to determine the total amount of reaction medium required.

The further required amount of reaction medium can then be metered into the reaction vessel using suitable means. The metering can take place at an adjustable speed or adjustable flow rate.

It is imperative not to adhere to metering at a constant flow rate. The flow rate can be adjusted as a function of the amount of reaction medium that has to be metered in. According to the invention, the neutralization process can therefore be carried out considerably more quickly.

The partial amount could be neutralizable in a measuring vessel of the measuring device independently of the remainder of the liquid to be neutralized, which is located in the reaction container. In this way, the partial amount can be analyzed and titrated very precisely, independently of the rest of the liquid to be neutralized. There is no contamination or material entry during the analyzing neutralization process of the small subset.

The remainder of the liquid to be neutralized could also be neutralizable by the measuring device, the remainder being able to be conveyed into and through the measuring device. This makes it possible to provide connections for hoses or feed lines for reaction media only on the measuring device. The reaction vessel does not have to have such connections. The reaction medium is fed to the measuring device, while the liquid to be neutralized is pumped through the measuring device.

An electronic control could be provided which determines the amount of reaction medium and / or the speed of its metering based on the ratio of the partial amount to the total liquid to be neutralized and controls the dosing device during or after the neutralization of the partial amount so that the amount of reaction medium and the speed of its metering is maintained. As a result, the neutralization process of a very large amount of liquid to be neutralized can be carried out particularly quickly and precisely. The scalability of the dosing device enables a quick neutralization process. It is also conceivable that the feed of the reaction medium into the reaction container has already started and its amount is recorded while the neutralization process of the partial amount is not yet completely completed. In this way, the neutralization process of the large amount of liquid can be accelerated further. In this respect, a kind of extrapolation or estimate can be made.

The electronic control could have an input device, preferably in the form of a touch panel, by means of which setpoint values or limit values for pH values, in particular neutral ranges, can be input. So the degree of neutralization can be adjusted.

The metering device could have a metering pump for basic reaction medium and / or a metering pump for acidic reaction medium. In this way, reaction medium can be conveyed into the measuring device in a targeted manner. Magnetic metering pumps that convey a defined amount of reaction medium per stroke could be used as metering pumps. Peristaltic pumps with stepper motors could also be used as metering pumps, with a defined amount of reaction medium being conveyed per step angle. It is essential that the metering pump can be controlled in such a way that its delivery rate can be increased by a calculable factor. So if a quantity x can be conveyed with one stroke or step angle, ten times the amount should be conveyable with ten strokes or ten step angles.

The metering device could comprise a canister for acidic reaction medium and / or a canister for basic reaction medium. As a result, the metering device has a compact design. The metering device can form a structural unit with the metering pumps and the canisters, which is accommodated in a housing.

The measuring device could comprise a measuring vessel, a stirrer, a temperature sensor and a pH sensor. Thus, as a structural unit, a small portion of a liquid can be received in the measuring device and homogenized by the stirrer. The pH value of the partial quantity can be determined by the pH sensor. The temperature sensor enables the neutralization system to be monitored so that it does not overheat and be damaged.

In addition to the reaction container, a storage container could be provided, from which liquid can be pumped into the reaction container by means of a feed pump. As a result, during a neutralization process, the liquid to be neutralized in the reaction container can continue to flow into the storage container.

The liquid to be neutralized could be circulated in the reaction container and in the measuring device by means of a circulation pump. This enables the liquid to be homogenized and neutralization is accelerated.

The neutralization system is advantageously designed as a module which comprises a housing, frame or a container so that it can be set up in a simple manner in a laboratory or within a system and flanged to locally existing lines.

• 1 eine Schnittansicht einer modulartigen Neutralisationsanlage, die ein Gehäuse umfasst, in dem der Vorlagebehälter nebst Pumpen, der Reaktionsbehälter, die Messvorrichtung und die Dosiereinrichtung mit Dosierpumpen und Kanistern aufgenommen ist,
• 2 die als bauliche Einheit vorliegende Messvorrichtung gemäß 1 in einer Schnittansicht von vorne,
• 3 die Messvorrichtung gemäß 1 in einer Schnittansicht von der Seite,
• 4 die Messvorrichtung gemäß 1 in einer Ansicht von oben,
• 5 schematisch das Befüllen des Messgefäßes der Messvorrichtung,
• 6 schematisch das Überlaufen der Messvorrichtung, wobei die überschüssige zu neutralisierende Flüssigkeit zurück in den Reaktionsbehälter läuft,
• 7 schematisch das Durchmischen der Teilmenge der zu neutralisierenden Flüssigkeit in der Messvorrichtung durch einen Rührer,
• 8 schematisch das Zudosieren von Natronlauge,
• 9 schematisch das Pumpen der Teilmenge zurück in den Reaktionsbehälter,
• 10 schematisch das Zudosieren von Salzsäure,
• 11 schematisch das Pumpen der Teilmenge aus 10 zurück in den Reaktionsbehälter,
• 12 schematisch das Überwachen der Temperatur im Messgefäß der Messvorrichtung sowie das Beenden des Zudosierens von Reaktionsmedium,
• 13 schematisch das Abpumpen einer neutralisierten Flüssigkeit aus der Messvorrichtung, und
• 14 ein Diagramm zur Erläuterung des Neutralpunkts.

Show in the drawing

• 1 a sectional view of a modular neutralization system which comprises a housing in which the storage container and pumps, the reaction container, the measuring device and the metering device with metering pumps and canisters are accommodated,
• 2 the measuring device present as a structural unit according to 1 in a sectional view from the front,
• 3 the measuring device according to 1 in a sectional view from the side,
• 4th the measuring device according to 1 in a view from above,
• 5 schematically the filling of the measuring vessel of the measuring device,
• 6th schematically, the overflow of the measuring device, whereby the excess liquid to be neutralized runs back into the reaction container,
• 7th schematically the mixing of the partial amount of the liquid to be neutralized in the measuring device by a stirrer,
• 8th schematically the addition of caustic soda,
• 9 schematically the pumping of the partial amount back into the reaction vessel,
• 10 schematically the addition of hydrochloric acid,
• 11 schematically the pumping of the partial amount 10 back to the reaction vessel,
• 12 schematically, the monitoring of the temperature in the measuring vessel of the measuring device and the termination of the addition of reaction medium,
• 13 schematically the pumping of a neutralized liquid from the measuring device, and
• 14th a diagram to explain the neutral point.

1 shows that the components of the neutralization system, in one housing 1 are installed with height-adjustable feet. Instead of a housing, a frame or an installation space, such as a container, can also be used to install the components.

The components include a storage container 2 , a reaction vessel 3 , a measuring device 4th , an electronic controller 5 with touch panel 5a , a feed pump 6th , for pumping the liquid to be neutralized F. from the storage container 2 to the reaction vessel 3 , a circulation pump 7th to circulate the liquid F. in the reaction vessel 3 via the measuring device 4th and a canister for emptying 8th for an acidic reaction medium, namely an acid, with a suction lance, a canister 9 for a basic reaction medium, namely a lye, with a suction lance, a metering pump 10 for the basic reaction medium and a metering pump 11 for the acidic reaction medium.

Specifically shows 1 therefore a neutralization system, which the reaction tank 3 to absorb the liquid to be neutralized F. and a metering device 21st includes, with which of the liquid to be neutralized F. Reaction medium can be fed to neutralize them.

The neutralization system includes a measuring device 4th , into which a subset T the liquid to be neutralized F. can be initiated, with the measuring device 4th the subset T can be neutralized to determine a required total amount of reaction medium.

2 shows the measuring device 4th in a sectional view from the front. The measuring device 4th includes a process 12 , a measuring vessel 13 , a temperature sensor 14th , a stirrer 15th , a connection 16 for the supply of the basic reaction medium, one connection 17th for the supply of the acidic reaction medium, one connection 18th for the circulation pump 7th and a pH sensor 19. The 3 and 4th show further views of the measuring device 4th . 2 specifically shows that the measuring device 4th a measuring vessel 13 , a stirrer 15th , a temperature sensor 14th and a pH sensor 19 in one structural unit.

5 against this background shows schematically that the subset T in a measuring vessel 13 the measuring device 4th independent of the rest of the liquid to be neutralized F. that is in the reaction vessel 3 is located, can be neutralized.

6th shows schematically that the rest of the liquid to be neutralized F. through the measuring device 4th can be neutralized, with the rest in and through the measuring device 4th is conveyable through it.

1 shows that an electronic controller 5 it is provided that the amount of reaction medium and / or the rate of its metering on the basis of the proportion of the partial amount T to the entire liquid to be neutralized F. determined.

The dosing device 21st is controlled by the electronic control 5 after neutralizing the subset T controlled in such a way that the amount of reaction medium required to neutralize the total liquid to be neutralized is maintained F. is necessary and that the rate at which this reaction medium is metered in is maintained. The electronic control 5 has an input device, namely a touch panel 5a which setpoints or limit values for pH values can be entered.

1 further shows that the metering device 21st a metering pump 10 for basic reaction medium and a metering pump 11 for acidic reaction medium. The dosing device 21st further indicates a canister 8th for acidic reaction medium and a canister 9 for basic reaction medium.

1 also shows that in addition to the reaction vessel 3 a storage container 2 is provided from which liquid F. by means of a Feed pump 6th into the reaction vessel 3 is pumpable. The storage container 2 is in the specific example under the reaction vessel 3 arranged.

1 , especially in connection with the 6th , 9 and 11 , also shows that the liquid to be neutralized F. in the reaction vessel 3 and in the measuring device 4th by a circulation pump 7th is reversible.

• Die zu neutralisierende Flüssigkeit F wird im Vorlagebehälter 2 gesammelt, damit ein ungehinderter Zufluss von Abwässern auch während der Dauer der nachgeschalteten Neutralisation gewährleistet ist.

The functionality of the neutralization system described here is as follows:

• The liquid to be neutralized F. is in the storage container 2 collected so that an unhindered inflow of waste water is guaranteed even during the duration of the downstream neutralization.

A buffer volume within the storage container 2 is therefore designed in such a way that for the maximum duration tmax of the neutralization process, a maximum flow rate Qmax of waste water into the storage tank 2 can flow in without the storage tank 2 gets crowded. The following applies to the calculation of the buffer volume: $$V_{Puffer}=Q_{max}\times t_{max}$$

The feed pump 6th transports the wastewater from the storage tank for a long time 2 into the reaction vessel 3 until it has reached a maximum level. The reaction vessel 3 is constructed in such a way that the most accurate and reproducible recording of its content is guaranteed.

After reaching the maximum level in the reaction vessel 3 stops the feed pump 6th and a circulating feed pump 7th turn on. The liquid to be neutralized F. circulates through the circulation over the measuring device 4th back into the reaction vessel 3 until the measurement of the pH value in the measuring device 4th provides a stable pH value.

Then the neutralization process starts, which will be described in detail later. Once the neutralization process is complete, the reaction vessel becomes 3 emptied and refilled after reaching its minimum level. The neutralization process then starts all over again.

• Schritt 1: Das Messgefäß 13 der Messvorrichtung 4 wird mit der zu neutralisierenden Flüssigkeit F aufgefüllt. Dieser Schritt ist in 5 schematisch dargestellt.

The neutralization process or the neutralization procedure comprises the following steps:

• Step 1: the measuring vessel 13 the measuring device 4th becomes with the liquid to be neutralized F. filled up. This step is in 5 shown schematically.

As soon as the measuring vessel 13 is filled, excess liquid runs out F. back to the reaction vessel 3 . This creates the liquid to be neutralized F. homogenized. This is schematically in 6th shown.

Step 2: the circulation pump 7th is turned off and the subset T the liquid to be neutralized F. that is now isolated in the measuring vessel 13 is located with the stirrer 15th mixed. This step is in 7th shown.

The subset to analyze T , namely a reference quantity, is set automatically because of the process 12 a return to the reaction vessel 3 is provided.

Step 3a: the pH of the subset T is measured with the pH sensor 19. When the measured pH value is below a set value, the dosing pump 10 for the basic reaction medium from the canister 9 Lye sucked in, specifically caustic soda is sucked in, and through the connection 16 for supplying the basic reaction medium alkali to the partial amount T filled in or metered in. This step is schematically shown in 8th shown.

After reaching the neutral point 20th which in 14th shown, the stirrer stops 15th . The number of steps of the dosing pump 10 for the dosage of the basic reaction medium in the subset T was necessary, is multiplied by a dosing factor using the following formula: $$\frac{N_{\mathrm{S.}cHritte\mathrm{D.}Osierpumpe}\times V_{\mathrm{R.}eaktiOnsbeHÄlter}}{V_{\mathrm{M.}esseinricHtunG}}$$

Step 4a: The amount of basic reaction medium required, calculated on the basis of the above formula, is now placed in the measuring vessel 13 added while the liquid to be neutralized F. from the reaction vessel 3 through the measuring device 4th is pumped. This step is in 9 shown,

Step 5: If the pH value lies within an adjustable range, in particular a neutral range, during an adjustable control time, the neutral liquid is pumped out. This is in 13 shown schematically. If corrections are necessary, these are made automatically.

Step 6: When a lower fill level of the reaction vessel 3 is reached, the pumping process of the now neutralized liquid stops F. and the process starts again with step 1.

• Schritt 3b: Der pH-Wert der Teilmenge T wird mit dem pH-Sensor 19 gemessen. Liegt der gemessene pH-Wert oberhalb eines eingestellten Sollwerts, wird von der Dosierpumpe 11 für das saure Reaktionsmedium aus dem Kanister 8 Säure angesaugt, konkret wird Salzsäure angesaugt, und durch den Anschluss 17 für die Zufuhr des sauren Reaktionsmediums Säure in die Teilmenge T eingefüllt. Dieser Schritt ist schematisch in 10 dargestellt.

As an alternative to steps 3a, 4a, 5 and 6, steps 3b, 4b, 5 and 6 can also follow steps 1 and 2:

• Step 3b: The pH of the subset T is measured with the pH sensor 19. If the measured pH value is above a set value, the dosing pump 11 for the acidic reaction medium from the canister 8th Acid sucked in, specifically hydrochloric acid sucked in, and through the connection 17th for the supply of the acidic reaction medium acid into the partial amount T filled. This step is schematically shown in 10 shown.

After reaching the neutral point 20th the stirrer stops 15th . The number of steps of the dosing pump 11 for the metering of the acidic reaction medium into the subset T was necessary, is multiplied by a dosing factor using the following formula: $$\frac{N_{\mathrm{S.}cHritte\mathrm{D.}Osierpumpe}\times V_{\mathrm{R.}eaktiOnsbeHÄlter}}{V_{\mathrm{M.}esseinricHtunG}}$$

Step 4b: The amount of acidic reaction medium required, calculated on the basis of the preceding formula, is now metered in while the liquid to be neutralized F. from the reaction vessel 3 through the measuring device 4th is pumped. This step is in 11 shown.

Step 5: If the pH value lies within an adjustable range during an adjustable control time, the neutral liquid is pumped out. This is in 13 shown schematically. If corrections are necessary, these are made automatically.

Step 6: When a lower fill level of the reaction vessel 3 is reached, the pumping process of the now neutralized liquid stops F. and the process starts again with step 1 .

The temperature in the measuring vessel 13 is controlled by the temperature sensor 14th constantly monitored. Becomes the maximum temperature in the measuring vessel 13 is exceeded, the dosing process stops and the neutralization system waits until the liquid has cooled down. This is in 12 shown schematically.

14th shows the course of a neutralization process using the example of the neutralization of a base. The neutral range N is mostly in the steepest part of the characteristic K so that even small amounts of added reaction medium lead to a large change in the pH value.

In the flat part of the curve K the pH value changes very slowly. If a large amount of reaction medium is introduced per unit of time, the regulation is imprecise and overruns. If only a small amount of reaction medium is introduced per unit of time, it takes a very long time until the neutral range N is reached.

According to the invention, the neutral point 20th when analyzing the subset T reached as quickly as possible and can even be exceeded.

Thus, the steep part of the curve K can be reached as soon as possible. The dosage is then drastically reduced and the neutral pH range, namely the neutral range, in fine gradations N , reached.

The amount of reaction medium determined for this in the partial amount T is used to calculate the amount of the reaction medium to be added, which is used to neutralize the total amount of the liquid to be neutralized F. necessary is.

The larger amount of reaction medium that is also required can then be metered in very quickly and essentially only limited by any temperature increases.

Advantageously, only one pH measurement is necessary, namely in the measuring vessel 13 . There is no risk of overdose.

The housing is advantageous 1 according to 1 a height of 80 cm, a width of 60 cm and a depth of 50 cm. The storage container 2 has a volume of 40 liters. The entire neutralization system is therefore very compact and space-saving.

List of reference symbols

1

casing

2

Storage container

3

Reaction vessel

4th

Measuring device

5

electronic control with touch panel

5a

Touch panel

6th

Feed pump

7th

Circulation pump

8th

Canister for acidic reaction medium

9

Canister for basic reaction medium

10

Dosing pump for basic reaction medium

11

Dosing pump for acidic reaction medium

12

procedure

13

Measuring vessel

14th

Temperature sensor

15th

Stirrer

16

Connection for the supply of the basic reaction medium

17th

Connection for the supply of the acidic reaction medium

18th

Connection for the circulation pump

19th

pH sensor

20th

Neutral point

21st

Dosing device

A.

alkaline range

F.

liquid to be neutralized

K

curve

T

Subset of F

N

Neutral range or neutral pH range

S.

acidic area

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 0567838 B1 [0002]

Claims (10)

Neutralization system, comprising a reaction container (3) for receiving a liquid (F) to be neutralized and a metering device (21) with which the liquid (F) to be neutralized can be supplied with reaction medium for neutralization, characterized in that the neutralization system has a measuring device (4) comprises, into which a subset (T) of the liquid (F) to be neutralized can be introduced, the subset (T) being at least partially or completely neutralizable with the measuring device (4) to determine a required total amount of reaction medium. Neutralization system after Claim 1 , characterized in that the partial amount (T) in a measuring vessel (13) of the measuring device (4) can be neutralized independently of the remainder of the liquid (F) to be neutralized, which is located in the reaction container (3). Neutralization system after Claim 2 , characterized in that the remainder of the liquid (F) to be neutralized can also be neutralized by the measuring device (4), the remainder being conveyable into and through the measuring device (4). Neutralization system according to one of the preceding claims, characterized in that an electronic control (5) is provided which determines the amount of reaction medium and / or the speed of its metering on the basis of the ratio of the partial amount (T) to the total liquid to be neutralized (F) determined and the metering device (21) controls during or after the neutralization of the partial amount (T) so that the amount of reaction medium and the rate of its metering are maintained. Neutralization system after Claim 6 , characterized in that the electronic control (5) has an input device by means of which setpoint values or limit values for pH values can be entered. Neutralization system according to one of the preceding claims, characterized in that the metering device (21) has a metering pump (10) for basic reaction medium and / or a metering pump (11) for acidic reaction medium. Neutralization system according to one of the preceding claims, characterized in that the metering device (21) comprises a canister (8) for acidic reaction medium and / or a canister (9) for basic reaction medium. Neutralization system according to one of the preceding claims, characterized in that the measuring device (4) comprises a measuring vessel (13), a stirrer (15), a temperature sensor (14) and a pH sensor (19). Neutralization system according to one of the preceding claims, characterized in that, in addition to the reaction container (3), a storage container (2) is provided, from which liquid (F) can be pumped into the reaction container (3) by means of a feed pump (6). Neutralization system according to one of the preceding claims, characterized in that the liquid (F) to be neutralized can be circulated in the reaction container (3) and in the measuring device (4) by a circulating feed pump (7).

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