DE102007007046A1 - Device for the perfusion of reaction chambers, comprises a storage tank for the intake having excess pressure, a storage tank for the outflow having lower pressure, level sensors arranged in the tanks, and/or a controllable pump - Google Patents

Abstract

The invention relates to a device for the flow through a reaction space and a method suitable for this purpose.
With the present device and the present method, it is now possible that a passive and non-contact, continuous flow through the reaction space can be achieved by an air pressure difference in the gas space of the reservoir for the inflow and outflow of the medium.

Description

The The invention relates to a device for the flow through a reaction space and a suitable method.

at the implementation Depletion studies in simulated water-saturated sediments have so far been either batch degradation experiments, d. H. Stand tests without flow, or flowed through once columns or repeatedly flowed through Columns, through which the test medium is conveyed by means of a peristaltic pump, used. These previously known devices and methods have some disadvantages. So batch degradation experiments are not suitable, which flowed through in one Aquifers to simulate prevailing exchanges. At one time perfused columns an inflow or outflow measurement of the test substance takes place. The residence times or contact times between the test substance and sediment are therefore limited. If the test medium is pumped by peristaltic pumps, are by entrained abrasive substances z. B. from the filler the column, Short service life due to blockage of hoses or material fatigue used materials guaranteed. The tubing used is the peristaltic pumps It is usually soft plastics with usually high absorption potential across from most potential test substances.

It is therefore an object of the invention, an easy-to-handle device to create, with a passive, non-contact, continuous flow a reaction space over a longer one Period of, for example, more than 360 days without the above Disadvantages possible becomes. It is a further object of the invention to provide an easy-to-handle To create a process by which a passive, continuous flow of a Reaction space over a longer one Period of, for example, more than 360 days without the above Disadvantages can be achieved.

outgoing from the preamble of claim 1, the object is achieved with the specified in the characterizing part of claim 1 features. Farther The object is achieved on the basis of the preamble of claim 4 according to the invention with the in the characterizing part of claim 4 specified features.

In surprising Way has been shown that by an air pressure difference in the Gas space of the storage tank for the Inlet and outlet of the medium a passive and non-contact flow through the Reaction space possible is. In the context of the present invention, under the name "passive and non-contact "flow, one flow understood without involvement of a pump, which is in contact with the medium comes. The medium flowing through the reaction space flows alone due to the prevailing air pressure difference, the z. B. by a pump can be generated, between the storage containers through the reaction space. Here it may be sufficient, for example a pressure difference of about 30 to 50 mbar prevails. Depending on desired flow rate however, any pressure difference can pass through the reaction space chosen become.

Becomes in a "closed System "worked, d. H. there is no contact with the atmosphere of the environment, in the Gas space of the reservoir of the inlet z. B. by means of a pump generates an overpressure while in the gas space of the reservoir for the Drain automatically creates a negative pressure. In a further advantageous execution However, it is also possible to use the invention in an open system work. In this case, either the gas space of the reservoir of the Inflow applied an overpressure or to the gas space of the reservoir of the drain is a Low pressure applied.

After this the medium from the reservoir the feed through the reaction space in the reservoir of the Flowed down is, it can be returned from here through the reaction space, by now in the gas space of the reservoir of the drain, now the inlet, an overpressure is created. So mutually a flow through the Reaction space to be carried out from the two storage tanks, so that a continuous flow can be achieved. This can be done via level sensors and a controllable pump, which the pressure difference in the respective gas chambers generated, the mutual flow are brought about.

At the reaction space can As required, any number of storage containers (eg 1-10 storage containers) are connected become. So it is possible, for example, reservoir with to connect different test media to the reaction chamber and to vary the feed from the respective storage containers.

In the context of the present invention, "reaction space" is understood to mean a vessel in which take place by biological and / or physical means degradation reactions or filtration reactions. These containers can be fixed bed reactors such as column reactors in any volume size.

Under the term "medium" should in the context aqueous solutions be understood, such as fortified with test substances Groundwater or synthetic media, for example, nutrients for microorganisms or catalysts for involve certain reactions.

The aforementioned embodiments are examples to which, however, the invention is not limited should.

The present invention has proven particularly suitable for carrying out and simulating degradation processes in water-saturated sediments with variably adjustable flow rates. Due to the closed system, ie no contact with the atmosphere of the test environment, it is possible to work under both aerobic and anaerobic conditions. So it is possible, for example, to work under defined adjustable gas conditions such. B. under a nitrogen atmosphere, helium or CO ₂ atmosphere and also a balance of the degradation process can be performed.

By the passive and non-contact flow it comes, in contrast to, for example, systems with a peristaltic pump, not to wear out pumping hoses by entrained abrasive substances from the reaction space or to material fatigue like z. B. of seals or the like.

A automated simulation more realistic Groundwater flow rates is through the present invention over a period of more possible about 360 days, without, for example, hoses, Vessels or Pumps must be replaced or for example, a refilling of the medium necessary becomes. According to the prior art are so far only lives of possible until a few weeks.

So is also an easy-to-handle investigation of the degradation and / or Filtration over a long period possible. It is still possible to carry out any number of experimental variants, eg. B. in the form of supply from different test media, parallel or reciprocal from the storage containers supplied can be or in the form of a different gas atmosphere can be generated in the closed system.

The Medium, such as. B. the enriched with the test substances groundwater, flows passive, non-contact and continuously in the closed system alternately the reaction space, such as a filled with aquifers column. The flow or the flow is variably adjustable with medium Flow rates of, for example, 1 to 5 m / day.

advantageous Further developments are specified in the subclaims.

The Invention further relates to a method for passive, non-contact, continuous flow a reaction space.

The Drawing shows schematically one of many possible embodiments the device according to the invention.

It shows:

1 : Schematic arrangement of the device for passive, non-contact, continuous flow through a reaction space

1 shows a schematic arrangement of the device for passive, non-contact, continuous flow through a reaction space. The storage tank 1 the inlet is via a pipe 1a which is a three-way valve 9 having, with the reaction space 2 connected. This one is over a line 3a with the reservoir 3 connected to the process. The reservoir 1 and 3 the inlet or outlet are with a level sensor 4 , as well as an entry or exit 10 and 11 for aeration and sampling of the gas chambers 7 and 8th , fitted. A pump 5 , is about a controller 6 with the level sensors 4 connected and to the gas rooms 7 and 8th the reservoir 1 and 3 connected.

in the Below, the individual process steps will be described in greater detail by way of example become:

1. Commissioning of the device

• - Screw on the stainless steel reducer at the lower constriction of the reaction chamber 2 , as well as the stainless steel cover GL 45 at the upper threaded opening.
• - For the connection The Teflon clamping rings should be used between metal and glass.
• - The connection between reducer and three-way valve 9 as well as three-way valve and reservoir 1 via PFA hose pieces.
• - The upper end of the reaction space 2 comes with stainless steel lid, stainless steel fitting and PFA hose with reservoir 3 connected. A seal is made via the PTFE seal and the bulkhead screw cap.
• - The assembly of the PFA hoses of the reaction chamber 2 via stainless steel fittings on the long tube of the reservoir 1 and 3 ,
• - The connection of the PFA hoses 4a and 4b to the pump 5 takes place over the short tubes
• - The sealing of the lid via silicone seals and screw cap, the side access 10 and 11 over screw cap and septa.
• - The level sensors 4 are mounted by turning the stainless steel screw with the Teflon insert into the provided thread and inserting the stainless steel rod through the insert. It should be noted that the Teflon insert looks out about 3 mm above the lower edge of the lid.
• - The PFA hoses are connected to the Pharmedschlauch (pump hose).

• – Die Vorrichtung wird in die dafür vorgesehenen Halterungen gestellt.
• – Anschließend erfolgt die Verbindung der Füllstandssensoren mit der Verteilung und dem Verbindungskabel zur Kontrolleinheit.

For a sterile operation of the device, it is sterilized before proceeding for about 20 min and 121 ° C in an autoclave. A check is carried out with a so-called autoclaving tape on which black stripes are recognizable after a successful process.

• - The device is placed in the appropriate brackets.
• - Subsequently, the connection of the level sensors with the distribution and the connection cable to the control unit.

With the switching on of the device, the pump generates a pressure difference within the reservoir of the medium, preferably in the closed system, an overpressure in the reservoir 1 the inlet and a negative pressure in the reservoir 3 of the process.

control unit

The Control unit is used for parallel control of, for example 22 devices and the measurement of the level sensors.

• – Gruppe I Vorrichtung Nr. 1 bis 8,
• – Gruppe II Vorrichtung Nr. 9 bis 16,
• – Gruppe III Vorrichtung Nr. 17 bis 22, – Individuell einstellbare Flussrate Jede Gruppe ist dabei mit einer so genannten Synchronisationsfunktion programmiert. Dies bedeutet, dass nachdem eine Vorrichtung einen definierten Flusszyklus vollendet hat (Vorratsbehälter 1 → 3 → 1, siehe Skizze), verbleibt die Vorrichtung solange in diesem Zustand, bis alle weiteren Vorrichtungen der Gruppe denselben Zustand erreicht haben. Diese Funktion dient der Harmonisierung der einzelnen Flussraten der Vorrichtungen einer Gruppe. – Ist der Flusszyklus einer Vorrichtung außerhalb eines vorher bestimmten und eingestellten Zeitintervalls, z. B. 4 Stunden nach dem letzten Kontakt des Füllstandssensors der letzten Vorrichtung der Gruppe, wird die betroffene Vorrichtung von der Kontrolleinheit aus der Gruppe herausgenommen und außerhalb der Gruppe weiter betrieben. Für jede Gruppe ist dieses Zeitintervall festzulegen und in das entsprechende Eingabefeld der Bildschirmmaske einzutragen. Ein Überschreiten des definierten Zeitintervalls wird durch die Kontrolleinheit sowie in der Eingabemaske des Bildschirms in Form eines Lichtsignals angezeigt. – Die restlichen Vorrichtungen der Gruppe nehmen ihren Betrieb wieder auf und vollziehen den nächsten Flusszyklus. – Alle Operationen der Kontrolleinheit werden in einem zentralen „log File" aufgezeichnet. Darüber hinaus werden die Daten der einzelnen Gruppen betreffend der Wechselzeitpunkte, d. h. Kontaktzeitpunkt mit den Füllstandssensoren (Datum, Uhrzeit) und der Dauer der Flusszyklen in spezifischen Tabellen auf dem Bildschirm angezeigt und in individuellen „log files" gespeichert. – Die Einstellung der einzelnen Wechselvolumina erfolgt über die Position der Füllstandssensoren in den Vorratsbehältern 1 und 3. Dieses sollte ca. die Hälfte des eingesetzten Gesamtvolumens betragen, um eine vollständige Durchmischung zu garantieren. Sobald ein Kontakt mit den Füllstandsensoren erfolgt, wird die Pumpe umgeschaltet und die Strömungsrichtung gewechselt. Hierzu wird mittels der steuerbaren Pumpe 5 an den Vorratsbehälter, an den zuvor ein Unterdruck angelegt war, ein Überdruck angelegt, so dass das Medium nun aus diesem Vorratsbehälter in Richtung des Reaktionsraums 2 strömt. Die gravimetrische Bestimmung und Kontrolle des Wechselvolumens erfolgt über den Anschluss einer Waage an die jeweilige Vorrichtung. Die Software der Kontrolleinheit zeichnet dabei die Wechselvolumina über die Messung der Zustände der Vorratsbehälter 1 und 3 auf (voll, leer, voll). – Die Flussrate einer jeden Vorrichtung berechnet sich aus den spezifischen Wechselvolumina pro Stunde geteilt durch das Volumen des Reaktionsraumes multipliziert mit der Höhe der Sedimentsäule in dem Reaktionsraum nach der folgenden Formel:
  

The devices can be divided into 3 groups as follows, which can be controlled with different flow rates.

• Group I device Nos. 1 to 8,
• Group II device nos. 9 to 16,
• - Group III device no. 17 to 22, - Individually adjustable flow rate Each group is programmed with a so-called synchronization function. This means that after a device has completed a defined flow cycle (reservoir 1 → 3 → 1 , see sketch), the device remains in this state until all other devices of the group have reached the same state. This function is used to harmonize the individual flow rates of the devices in a group. - Is the flow cycle of a device outside of a predetermined and set time interval, z. B. 4 hours after the last contact of the level sensor of the last device of the group, the affected device is taken out of the control unit from the group and operated outside the group on. For each group, this time interval must be specified and entered in the appropriate input field of the screen mask. Exceeding the defined time interval is displayed by the control unit and in the input screen of the screen in the form of a light signal. - The remaining devices of the group resume their operation and complete the next flow cycle. - All operations of the control unit are recorded in a central "log file" In addition, the data of the individual groups concerning the change times, ie contact time with the level sensors (date, time) and the duration of the flow cycles in specific tables in the picture The individual change volumes are set via the position of the level sensors in the storage containers 1 and 3 , This should be about half of the total volume used to guarantee complete mixing. As soon as there is contact with the level sensors, the pump is switched over and the flow direction is changed. This is done by means of the controllable pump 5 to the reservoir to which a negative pressure was previously applied, applied an overpressure, so that the medium now from this reservoir in the direction of the reaction space 2 flows. The gravimetric determination and control of the change volume is carried out by connecting a balance to the respective device. The software of the control unit records the changing volumes via the measurement of the conditions of the storage container 1 and 3 on (full, empty, full). The flow rate of each device is calculated from the specific change volumes per hour divided by the volume of the reaction space multiplied by the height of the sediment column in the reaction space according to the following formula:
  

The Flow rate of a group results from the synchronization function from the slowest single flow rate of a group.

The Pore volumes of the aquifers used are being determined the flow rates are not taken into account.

Claims (5)

Device for flowing through a reaction space ( 2 ), comprising a reservoir ( 1 ) for the inlet and a storage container ( 3 ) for the process, wherein the gas spaces ( 7 ) and ( 8th ) of the two storage containers ( 1 ) and ( 3 ) have an air pressure difference, level sensors ( 4 ) in the reservoirs of the inlet and outlet, and a controllable pump ( 5 ). Apparatus according to claim 1 characterized by, an overpressure in the reservoir ( 1 ) of the inlet and / or a negative pressure in the reservoir ( 3 ) of the process. Process for flowing through a reaction space ( 2 ), characterized in that in the gas spaces ( 7 ) and ( 8th ) the reservoir ( 1 ) and ( 3 ) for the inlet and outlet an air pressure difference is generated and a mutual flow through the reaction space ( 2 ) from the storage containers ( 1 ) and ( 3 ) using the level sensors ( 4 ) and a controllable pump ( 5 ) is carried out. A method according to claim 3, characterized in that in the closed system to the reservoir ( 1 ) of the inlet by means of pump ( 5 ) is applied, so that in the reservoir ( 3 ) of the drain creates a negative pressure A method according to claim 3, characterized in that in the open system to the reservoir ( 1 ) of the inlet by means of pump ( 5 ) an overpressure is applied or to the reservoir ( 3 ) of the drain by means of a pump ( 5 ) A negative pressure is applied.