GB2435624A

GB2435624A - Chamber Heater

Info

Publication number: GB2435624A
Application number: GB0604074A
Authority: GB
Inventors: Duncan Guthrie
Original assignee: Vapourtec Ltd
Current assignee: Vapourtec Ltd
Priority date: 2006-03-01
Filing date: 2006-03-01
Publication date: 2007-09-05
Anticipated expiration: 2026-03-01
Also published as: GB0604074D0; GB2435624B

Abstract

A chemical synthesis reactant chamber for use in synthesis by flow chemistry comprises an elongate tube through which flows, in use, a fluid to be analysed by passing the fluid through and/or around a media to ensure conditions of heterogeneous flow within the tube; the tube wall being so constructed that the effect of the catalyst on the fluid can at least partially be viewed as the fluid passes through the reactant chamber in use; the tube being jacketed in order to allow a flow of heating fluid to embrace the tube and thereby heat, in use, the tube and its contents; the jacket being so constructed as to allow a user to view that part of the tube wall through which the effect of the reaction between the media and the fluid can be viewed; and the jacket incorporating means which, in use of the chamber, will promote agitation of the heating fluid flow around and/or along the tube wall.

Description

Chamber Heater

Field of the Invention

The invention relates to heated reactant chambers. The present invention is particularly concerned with reactant chambers used in the automation of flow chemistry for chemical synthesis.

yew of Art Known to the Applicant The art known by the applicant for heated reactant chambers comprises of chambers which encloses the reaction region in a box enclosure or "coffin'. The enclosure is constructed of materials which do not allow visual monitoring of the reaction process.

Heat is applied to the reaction area once the enclosure is closed around the reaction region.

Problem to be Solved The problem to be solved is how to visually monitor the reaction, from chemical compounds which make contact with catalyst resin beads, in a heated reaction chamber for chemical synthesis, when the only widely known way of arranging such reactions does not allow this; and when it is necessary to apply heat uniformly over the entire reaction area at 10 degrees thereabouts.

The reactant chamber must also be able to heat rapidly and cool rapidly.

The reactant chamber outer body must also not heat up excessively during normal operation.

Summary of the Invention

A chemical synthesis reactant chamber for use in flow chemistry analysis and comprising an elongate tube through which flows, in use, a fluid to be analysed by passing the fluid through and/or around a catalyst contained in the tube; the tube wall being so constructed that the effect of the catalyst on the fluid can at least partially be viewed as the fluid and catalyst interact in use; the tube being jacketed in order to allow a flow of heating fluid to embrace the tube and thereby heat, in use, the tube and its contents; the jacket being so constructed as to allow a user to view that part of the tube wall through which the effect of the catalyst on the fluid can be viewed; and the jacket incorporating means which, in use of the chamber, will promote agitation of the heating fluid flow around and/or along the tube wall.

By suitable selection of materials (eg glass of known kinds such as borosilicate glass) a chamber having these features can fulfil the inventor's objectives.

Preferably the heating fluid flow is swirled. This promotes an especially effective agitation of the airflow and minimises any tendency for a boundary layer to form around the tube waLl.

Preferably also the heating fluid is fed tangentially into the tube wall for the same reasons; even more advantageously if the heating fluid enters at or towards one end region of the tube.

The jacket may incorporate means which allow a temperature probe to feed back the temperature within the jacket; characterised in that such means are so constructed as to enable the temperature sensing tip of the probe to abut the tube wall. This gives a true reading in practice than if the probe merely sampled the fluid temperature within the jacket.

The invention includes within its scope a method of applying heat to a reactant chamber comprising the steps of: bringing heating fluid from a heating unit into contact with one end region of the wall of a reactant analysis tube; causing the heating fluid to agitate in a manner which enables a uniform heating of the tube wall; jacketing the tube so as to constrain the heating fluid to flow around the tube as the reaction proceeds; and so constructing and/or mounting the tube within the jacket, and the jacket in relation to the heating unit, that in use, the reaction taking place within the tube can at least partially be viewed by the user.

Brief Description of the FigwT

Figure 1 shows a perspective view of a heater case with an array of cylindrical chemical reactant chambers.

Figure 2 shows a cross-sectional view along axis A-A of the heater case.

Figure 3a shows a side elevation view of a reactant chamber for use with the apparatus of Figure 1; Figure 3b shows a side elevation view of the reactant chamber of Figure 3a reoriented at degrees clockwise to the view of figure 3a; Figure 3c shows a cross-sectional view along axis B-B of the reactant chamber.

Detailed Description of the Figures

Figure 1 shows an array of four separate heated cylindrical reactant chambers of two different configurations 1 and 2 each individually releasably mounted on an outer face of heater case 3. The array of chambers shown comprises various heights of chambers in order to aflow separate reaction to occur simuftaneously. The diameter of the reactant chambers may also, if necessary, be varied to accommodate particular reactions.

A front control panel 4 located to one side of the chambers 1, 2 houses four independent temperature indicators 5. The individual temperature indicators depict the temperature inside each respective reactant chamber. A temperature controller 6 controls the temperature settings for each reactant chamber.

Each reactant chamber has upper and lower couplings arranged in a vertical axial configuration. The lower coupling 7 is attached, in use, to pipes (not shown in the Figures) that supply compounds in solution required for chemical reaction inside the reactant chamber. The product produced by the chemical reaction is transferred from the reactant chamber, via further pipes (again not shown) that are connected to an upper coupling 8.

The upper portion of each cylindrical chamber incorporates an annular top face 9 with an inner diameter 10 of greater diameter than the pipe portion which traverses the face in order to define a gap between the pipe portion and the face. A similar annular lower face 11 is employed.

Projecting perpendicularly and placed substantially half way up the reaction region 12 (shown in Figure 2) from the reactant chamber is a thermocouple entry tube 9, which allows temperature monitoring of the outside wall of the chamber used for the chemica' reaction. When a thermocouple (of a kind known in itself) is inserted into tube 9 within its probe-end abutting the wall 18, of the innermost chamber cylinder. Axis line A-A represents the section used for the cross-sectional view in Figure 2.

Figure 2 shows a hot air heater 25 is mounted inside the case. Ambient air is supplied to the hot air heater from a supply cavity 13 located at the rear of the case. The cavity incorporates a fan 14 to create a pressure within the supply cavity that is greater than atmospheric. The pressure maintained within the supply cavity should be between 50 mbar and 500 mbar in excess of atmospheric pressure. The ambient air is heated by the heater to temperatures of up to 150 degrees and expelled through a nozzle 15. The air is heated as necessary to maintain the temperature of the reaction at the desired temperature. The nozzle narrows in cross-section and is oriented so that the warm air jet exiting the nozzle meets the walls of an inner cylinder 18 in a substantially tangential direction in order to swirl around the reaction region.

The reactant chamber incorporates multiple walls of concentric cylinders. The hot air from nozzle 15 is expelled into a heating cavity 16 formed between cylinder 17 and the inner most cylinder 18 surrounding the reaction region located at the heart of the reactant chamber, in which the compounds used in for example chemical synthesis, are heated. The hot air circulates around the total length of the heating cavity and exits at an exhaust port 19 located at an upper most region of the chamber. The exhaust port 19 expels the hot air into exit cavity 20. The exit cavity incorporates an extractor 26 located at the upper rearmost portion of the case to enable the extraction of expelled hot air from the case.

The hot air unit is thus capable of expelling ambient air from the supply cavity into the heating cavity via the nozzle 15 to cool down the reactant chamber.

The typical volume of air flow for the heating and cooling of the heater cavity is 0.8m3/ per minute for each heating cavity.

Surrounding the heating cavity 18 is another cavity 21 between cylinder 1 7 and outermost cylinder 22 which contains a vacuum. The vacuum functions as a heat insulator, required to reduce excessive heating of the outer surface of the reactant chamber and therefore reduces the risk of burn injury for the operators of chamber. A further function of this insulation is to reduce the heat loss between nozzle 15 and port 19. by reducing heat loss the reaction chamber can be maintained at a substantially constant temperature throughout its length. The cylinders are preferably of translucent material such as Borosilicate glass designed to withstand elevated temperatures. The reactant chamber is coated on its outside in a polymer coating 23, which if the cylinders shatter are capable of retaining broken glass debris.

The reaction region is where the chemical synthesis takes place of the compounds supplied. The reaction is governed by the flow of the compound through the reaction region, and the temperature of the reaction region. The reaction region is heated to a temperature in the range of ambient to 150 degrees, with a variability of less than +1-2.5 degrees over the reaction region.

The reactant chamber is maintained at the desired temperature by applying more or less power to the electrical heating element 25, so elevation or reducing the temperature of the air flowing through the heating cavity. The power to the heating element is controlled by a pulse with modulated signal. The degree of modulation being derived using a control algorithm employing proportion, derivation and integral terms based on the feedback from the temperature sensor inserted into tube 9, in an unknown manner.

The reactant region is preloaded in use with a media of generally known kind. The media ensure the compound makes contact with all the surface area of the media, in the form of a heterogeneous flow. The media can have a catalyst or reagent chemically attached to its surfaces by an earlier process. Suitable medias are polystyrene or bromostyrene resin beads of a generally known kind.

The typical flow rates required for chemical synthesis in the reaction region are 0.lml /per minute to 1-2m1/per mm.

Figure 3a shows an outwardly projecting hot air input port 24, which is placed on the same horizontal axis as the hot air exhaust port 19. The hot air input port is tapered in order to reduce the area at the nozzle exit thereby accelerating the air flow into the hot air cylinder 16. In addition, the end of the nozzle directs the air flow tangentially to the hot air cylinder in order to create swirl around the reaction region. This avoids the danger of a laminar flow building up against the cylinder wall and ensures uniformly accurate controllable heating and cooling of the cylinders. Figure 3a also shows the thermocouple entry hole 9 mounted perpendicular to the central longitudinal axis of the reactant chamber.

Figure 3b shows the reactant chamber, with the hot air import and exhaust port mounted perpendicular to the chamber. The thermocouple entry tube is again shown to be mounted perpendicular to the reactant chamber.

Figure 3c shows the hot air nozzle configuration which is used to transfer hot air around the reaction region. This configuration controls the hot air flow into the heating cavity.

The hot air is applied directly around the reaction region. The nozzle configuration applies the hot air, with a uniform thermal distribution throughout the entire heating cavity.

Figure 3c shows the relative angular positions of the nozzle, the thermocouple entry tube and the reactant chamber. The thermocouple entry tube is set at an angle of 45 degrees from the longitudinal axis of the nozzle.

Claims

Claims 1. A chemical synthesis reactant chamber for use in synthesis by

flow chemistry and comprising an elongate tube through which flows, in use, a fluid to be analysed by passing the fluid through and/or around a media to ensure conditions of heterogeneous flow within the tube; the tube wall being so constructed that the effect of the catalyst on the fluid can at least partially be viewed as the fluid passes through the reactant chamber in use; the tube being jacketed in order to allow a flow of heating fluid to embrace the tube and thereby heat, in use, the tube and its contents; the jacket being so constructed as to allow a user to view that part of the tube wall through which the effect of the reaction between the media and the fluid can be viewed; and the jacket incorporating means which, in use of the chamber, will promote agitation of the heating fluid flow around and/or along the tube waR.

2. A chamber according to claim 1 in which there is provided a media which has had a catalyst or reagent chemically attached to its surfaces.

3. A chamber according to claim 1 or claim 2 and in which the chamber induces swirled air flow.

4. A chamber according to any preceding claim in which the heating fluid is air.

5. A chamber in accordance with claim 3 in which the heating fluid is fed tangentially into the tube wall.

6. A chamber in accordance with claim 4 or 5 in which the heating fluid enters at or towards one end region of the tube.

7. A chamber in accordance with any of the previous claims where the jacket is insulated using a vacuum cavity.

8. A chamber according to any of the claims 1 to 7 in which the jacket incorporates means which allow a temperature probe to feed back the temperature within the jacket; characterised in that such means are so Constructed as to enable the temperature sensing tip of the probe to abut the tube wall.

9. Apparatus substantiauy as described herein with reference to and as illustrated in the accompanying drawings.

10. A method of applying heat to a reactant chamber comprising the steps of: bringing heating fluid from a heating unit into contact with one end region of the wall of a reactant analysis tube; causing the heating fluid to agitate in a manner which enables a uniform heating of the tube wall; jacketing the tube so as to constrain the heating fluid to flow around the tube as the reaction proceeds; and so constructing and/or mounting the tube within the jacket, and the jacket in relation to the heating unit, that in use, the reaction taking place within the tube can at least partially be viewed by the user.

11. A method according to claim 10 in which the heating fluid is caused to swirl.

12. A method according to claim 11 in which the heating fluid is fed tangentially onto the tube wall.

13. A method substantially as described herein with reference to the accompanying drawings.

Amendments to the claims have been filed as follows 1. A chemical synthesis reactant chamber for use in flow chemistry analysis and comprising an elongate tube through which flows, in use, a fluid to be analysed by passing the fluid through and/or around a media contained in the tube; the tube wall being so constructed that the effect of the media on the fluid can at least partially be viewed as the fluid passes through the reactant chamber in use; the tube being jacketed in order to allow a flow of heating fluid to embrace the tube and thereby heat, in use, the tube and its contents; the jacket being so constructed as to allow a user to view that part of the tube wall through which the effect of the reaction between the media and the fluid can be viewed; and the jacket incorporating means which, in use of the chamber, will promote agitation of the heating fluid flow around and/or along the tube wall.

2. A chamber according to claim 1 in which the fluid flows over and/or around a media which has had a catalyst or reagent chemically attached to its surfaces.

3. A chamber according to claim 1 or claim 2 and in which the chamber induces swirled flow. * *

4. A chamber according to any preceding claim in which the heating fluid is air.

5. A chamber in accordance with claim 3 in which the heating fluid is fed tangentially into the tube wall.

6. A chamber in accordance with claim 4 or 5 in which the heating fluid enters at or towards one end region of the tube.

7. A chamber in accordance with any of the previous claims where the jacket is insulated using a vacuum cavity.

8. A chamber according to any of the claims 1 to 7 in which the jacket incorporates means which allow a temperature probe to feed back the temperature within the jacket; characterised in that such means are so constructed as to enable the temperature sensing tip of the probe to abut the tube wall.

9. Apparatus substantially as described herein with reference to and as illustrated in the accompanying drawings.

10. A method of applying heat to a reactant chamber comprising the steps of: bringing heating fluid from a heating unit into contact with one end region of the wall of a reactant analysis tube; causing the heating fluid to agitate in a manner which enables a uniform heating of the tube wall; jacketing the tube so as to constrain the heating fluid to flow around the tube as the reaction proceeds; and so constructing and/or mounting the tube within the jacket, and the jacket in relation to the heating unit, that in use, the catalytic reaction taking place within the tube can at least partially be viewed by the user.

11. A method according to claim 10 in which the heating fluid is caused to swirl.

12. A method according to claim 11 in which the heating fluid is fed tangentially onto the tube wall.

* * 13. A method according to Claim 10 and substantially as described herein with reference to the accompanying drawings.