Patent Application
20250001326
The present invention relates to the area of evaporation, and more specifically to devices and methods for evaporation of liquids such as organic solvents.
Laboratory evaporators are devices capable of removing liquids, such as water or organic solvents, from preparations that need to be dry. Many industries use laboratory evaporators to prepare samples for analysis. The pharmaceutical, food, petroleum industries, and chemical laboratories all use evaporators for this reason.
Laboratory evaporators may use motion, gas, heat, or some combination to produce a dry sample ready for analysis. Specifically, in the sample preparation that commonly precedes analytical procedures, such as liquid chromatography, mass spectrometry etc, evaporator devices are commonly grouped as gas evaporators, such as nitrogen evaporators; vacuum evaporators; or rotary evaporators.
U.S. Pat. No. 5,176,799 (Biotage AB) relates to an evaporation apparatus including a vessel defining an opening at the top thereof and forming an evaporation chamber to hold a liquid composition. A condenser assembly is disposed above and hermetically sealed to the vessel, having a wall defining a condensation chamber communicating with the evaporation chamber through the opening, an accumulator for receiving liquid condensed on the wall, and a drain for removing liquid received by the accumulator. A fluid drive is disposed above the condenser assembly and adapted to produce fluid flow downwardly through the condensation chamber and into contact with the liquid composition in the evaporation chamber and then upwardly into the condensation chamber. A heating mechanism for heating the liquid composition is arranged in the evaporation chamber so as to cause evaporation thereof; and a cooling means are arranged for cooling the wall so as to produce condensation thereon of vapor included in the fluid flowing upwardly from the evaporation chamber.
U.S. Pat. No. 6,357,141 (Biotage AB) relates to an evaporating system for evaporating solvents from chemical samples held in supply plates, which accelerate evaporation by warming the samples in a hot air bath. The system includes adapters to allow the use of supply plates of varying heights, such as either standard micro-plates or deep well micro-plates. Specifically, an apparatus for evaporating solvents from chemical samples held in standard supply plates is described, wherein the supply plates are of the type having a horizontal upper surface, and a multitude of supply wells are arranged therein. The apparatus may comprise
U.S. Pat. No. 6,357,141 teaches that the described adapters which provides hot ait from underneath the plate bathe each well individually, while avoiding mixture with and dilution and/or contamination of the inert drying gas that contacts the samples.
Porvair Sciences markets the Ultravap® range of blowdown evaporators designed to remove the traditional laboratory ‘bottle neck’ of solvent evaporation from microplates. Some instruments are designed with a flat front profile and platform shuttle enables interfacing with liquid-handling robots for automation efficiency. According to its supplier, these products provide reproducible sample throughput by recent advancements in gas injection technology to directly and consistently deliver heated gas in each well and tube. The gas is provided as a continuous flow warmed by inline heating.
Finally, WO 2017/186679 (Biotage AB) describes an evaporation apparatus for evaporation of a liquid in a test tube, which evaporation apparatus includes at least one manifold with at least one nozzle, and a tank unit for a liquid with an associated heater for the liquid. It is suggested that the apparatus may utilize preheated gas heated with other or additional heating means arranged downstream the inlet. WO 2017/186679 teaches that in conventional evaporator apparatuses, the gas flow from each nozzle is largely dependent on the pressure in the gas system between the pressure regulator and the nozzle. For low gas flow rates the gas pressure gives the desired flow through the nozzle. However, if the gas flow rate is high the flow resistance of the gas system will restrict the gas flow; this may be counteracted by an overpressure generated in the system. In prior-art systems the pressure were controlled by means of a manual pressure regulator, while WO 2017/186679 teaches a control unit configured to gradually increase the gas pressure from a first low pressure to a set pressure.
In summary, there is an ongoing need in the field of lab evaporators for new solutions, which enable efficient evaporation using fast and easily operated evaporators having low energy consumption. For example, there is a need in this field of evaporators having more efficient heating resulting in lower energy consumption. Other needs are faster sample processing, and equipment better adapted to the limited space offered in most labs.
The term “a multiwell plate” is used herein for a plate of any size which includes a multitude of wells.
The term “heat sink” (also commonly spelled heatsink) is used herein for a passive heat exchanger that transfers the heat generated by an electronic or a mechanical device to a fluid medium, where it is dissipated away from the device, thereby allowing regulation of the device's temperature. As is well known, a heat sink comprises heat exchanging elements combined with a heat source of suitable dimensions.
The term ‘open-loop’ is used herein for a control system in which an input alters the output, but the output has no feedback loop and therefore no effect on the input. Open loop is used when maintaining tight temperature tolerance is not required and the operating environment is stable.
In a first aspect, the present invention relates to an evaporator comprising a plate holder arranged for rigidly holding a multiwell plate such that the horizontal upper surface thereof is vertically positioned at a desired level;
Thus, the present invention has found unexpected advantages of using an integrated heat sink in the manifold, which per definition is designed as a cooler most commonly seen in integrated circuits, as a heating element in laboratory evaporation. The heat sink presents a maximized surface area in contact with the medium surrounding it, which in the present context contributes to a more efficient heating than the prior art evaporators use.
As the skilled person will appreciate, thanks to the integration of the heating element into the manifold, the space needed for the evaporator according to the invention is greatly reduced compared to an evaporator using a traditional in line heater. Also thanks to the integration, the total heated mass i.e. everything that needs to be warm to heat the gas to the required level, is reduced compared to the traditional solution with an inline heater. Due to the fact that the heat sink is so close to the nozzles, there will be a more predictable relationship between gas nozzle temperature and heat sink temperature.
The evaporator of the invention will also entail low heat losses and short heat up time to working temperature, since as compared to the prior art, the heated parts are kept to a minimum both in size and thermal mass.
Using the advantage of the heat sink, an even temperature of the heated gas can be obtained. The temperature of the heat sink(s) is advantageously maintained within a predetermined range or at a predetermined value by open loop control.
The skilled person can easily choose a suitable type and function for a given multiwell plate-based evaporator. For example, the heat sink may be a pin cooler, such as a straight or a flared pin cooler.
Air velocity, choice of material, protrusion design and surface treatment are factors that affect the performance of a heat sink, and hence may impact the type selected. The heat sink may for example be made out of aluminium or copper.
In order to enable smooth and low energy operation, the heating element such as the heat sink(s) may be arranged for idle heat operation.
The evaporator according to the invention is advantageously a lab-type instrument, many of which are known and in common use. For example, the above-described U.S. Pat. No. 6,357,141 may provide further guidance with regard to known and basic principles of evaporators which may also be applicable to the herein described device and method.
One advantage of the present invention is that the use of a heat sink enables the instrument to use a mathematical model that calculates the heater temperature needed to reach the requested (or desired) nozzle temperature, using the gas flow and the requested nozzle temperature as input. Thus, as discussed in more detail below in relation to the method of the invention, the heating element can heat up to the correct temperature without using any gas flow. As a consequence, the gas consumption may be reduced as compared to the prior art.
As appears from the above, the evaporator according to the invention will have the correct temperature from the beginning, when the gas flow is started.
If desired, the instrument may be maintained in a stand-by type of pre heat mode with low heat losses, so the user can start the evaporation immediately.
Multiwell plates are available in various sizes, having a large range of wells.
The evaporator of the invention may be arranged to be connected on-line with one or more analysis apparatuses downstream of it. Said analysis apparatus may be selected from the group consisting of gas chromatographs, liquid chromatographs, mass spectrometers and apparatuses for flow injection analysis.
The present invention is useful to reduce the volume of a solvent, either to a certain extent or to dry or close to dry. For example, an evaporator according to the invention may be used for the reconcentration of liquid samples.
Thus, another aspect of the invention is a method of evaporating a solvent using pre-heated inert gas, which method comprises
Thus, the present method avoids the disadvantage of the prior art, where during the start of the process, the inert gas flow first needs to heat up the manifold, tubing and adapter plate and then gradually starts to get the correct temperature of the gas from the nozzle. As a consequence, the present invention provides for fast heat up time from a cold system to working temp, resulting in a faster evaporation than the prior art. Another advantage with the method is that the required volume of gas can be reduced, since the gas flow provides for efficient evaporation immediately.
The inert gas may be any gas that does not undergo chemical reactions under a set of given conditions, such as nitrogen gas, or any other gas which is inert in respect of the solvent to be evaporated.
The evaporator provided in the present method may be any embodiment of the herein presented evaporator according to the invention.
As appears from the above, turning to
Further, at least one gas heating and injecting manifold 3 is arranged above the plate holder 2 and having at least one injection nozzle 4 positionable approximately at said desired level. As the skilled person will appreciate, most evaporation processes will be performed with a plurality of nozzles 4, advantageously the same number of nozzles at there are wells in the microwell plate. Thus, each nozzle 4 is adapted to inject inert drying gas into a corresponding well of the multiwell plate.
In order to improve the evaporation process, the inert drying gas is warmed before being injected from a nozzle into a corresponding well. This is obtained according to the invention by one or more heating elements 5 arranged to warm the inert drying gas upstream of its injection into said wells. More specifically, according to the invention, in the manifold 3 said at least one heating element is a heat sink 6 which has been integrated into said at least one manifolds 3.
Turning to
Further in
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/SE2021/050987 | 10/8/2021 | WO |
