1. A vessel for storing a bulk product, the vessel comprising an air filter for cleaning the air which pneumatically conveys the bulk product into the vessel, wherein a means for restricting the air flow through said air filter is provided thereby elevating the pressure within the vessel to above atmospheric pressure.
2. A vessel according to claim 1, wherein the means for restricting the air flow is located at the outlet of the air filter.
3. A vessel according to claim 1, wherein the means for restricting the air flow is a valve.
4. A vessel according to claim 1, wherein the pressure inside the vessel is at least 50% of the pressure inside of a container from which the bulk product is conveyed.
5. A vessel according to claim 1, wherein the vessel is pressurised to between about 1 to 2 bar(g).
6. A vessel according to claim 1, wherein the vessel is a silo.
7. A vessel according to claim 4, wherein the container is a pneumatic tanker.
8. A vessel according to claim 1, wherein the air filter has a maximum flow velocity of 1.5m3minm2.
9. A vessel according to claim 1, wherein the air filter is positioned on a side wall of the vessel.
10. A vessel according to claim 9, wherein air filter is positioned within the lower half of the side wall.
11. A vessel according to claim 9, wherein the air filter is positioned substantially at or near ground level when the vessel is in use.
12. A vessel according to claim 1, wherein the vessel is adapted to pneumatically discharge the bulk product from the vessel.
13. A vessel according to claim 12, wherein a screw conveyor is connected to the vessel for discharging the bulk product under pressure from the vessel.
14. A vessel according to claim 1, wherein a means for detecting the level of bulk product within the vessel is provided.
15. A vessel according to claim 14, wherein the detecting means is at least one level probe or load cell.
16. A vessel according to claim 1, wherein the bulk product is a powder or granular product.
17. A vessel according to claim 17, wherein the vessel has a fluidisable base.
18. A vessel according to claim 1, wherein the vessel is located within an ISO frame.
19. A kit comprising a vessel according to claim 1, an ISO frame and a pre-cast concrete base.
20. An air filter for use on a vessel into which a bulk product is pneumatically conveyed, said air filter being provided with means for restricting the air flow through the filter, thereby resulting in an elevation of pressure within the vessel to above atmospheric pressure.
21. An air filter according to claim 20, wherein the means of restricting the air flow is a value located at the outlet of the air filter.
22. An air filter according to claim 20, wherein the vessel is a silo.
23. A method of filtering the air displaced after a bulk product has been pneumatically conveyed into a vessel, said method comprising restricting the air flow through the air filter thereby elevating the pressure in the vessel to above atmospheric pressure.
24. (canceled)
25. (canceled)
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
what is claimed is:
1. An electrochemical cell for sensing an analyte in the presence of an interferent, the electrochemical cell comprising a reference electrode and a working electrode connected by a potentiostatic circuit, the analyte reacting at the working electrode giving a first component of current, the interferent undergoing an electrochemical reaction giving a second component of current, the presence at the reference electrode of the interferent leading to a shift in the potential of the reference electrode, wherein the shift in the potential of the reference electrode and the action of the potentiostatic circuit leads to a third component of current, wherein properties of the electrochemical cell which affect the magnitude of the third component of current are selected so that the third component of current acts to partially, completely or over compensate for the second component of current.
2. The electrochemical cell of claim 1 wherein the interferent cohabits with the analyte gas.
3. The electrochemical cell of claim 1 wherein the interferent is generated by the counter electrode.
4. The electrochemical cell of claim 1 wherein the properties of the electrochemical cell which affect the magnitude of the third component of current are one or more of the capacitance of the working electrode, the metal on the reference electrode, the oxidation state of the metal on the reference electrode, the redox couple, capacitance or geometry of the reference electrode.
5. The electrochemical cell of claim 1, being a gas sensor.
6. The electrochemical cell of claim 5 wherein the analyte is carbon monoxide and the interferent is hydrogen.
7. The electrochemical cell of claim 5 wherein the working electrode is a circular gas porous disk.
8. The electrochemical cell of claim 5 wherein the reference electrode is an annulus, coaxial with the working electrode.
9. The electrochemical cell of claim 5 wherein the reference electrode is at least partially exposed to the analyte gas without electrolyte between the electrode and analyte gas.
10. The electrochemical cell of claim 5 wherein the capacitance of the working electrode is at least 1 mF.
11. The electrochemical cell of claim 1 which, in use, makes measurements periodically.
12. An electrochemical cell for sensing an analyte in the presence of an interferent, the electrochemical cell comprising a working electrode and a first reference electrode connected by a potentiostatic circuit, the interferent not affecting the reference electrode thus avoiding a shift in the potential of the reference electrode, the analyte reacting at the working electrode giving a first component of current, the interferent undergoing an electrochemical reaction giving a second component of current characterized in that there is further provided a second reference electrode, configured so as to be exposed to the interferent, the interferent causing a shift in the potential of the second reference electrode, the second reference electrode being connected to the first reference electrode by a potentiometric circuit for providing a measure of the potential difference between the first and second reference electrodes, said potential difference between the first and second reference electrodes being used to calculate the second component of current and thereby provide a measure of the concentration of the analyte which has reduced or no dependency on the concentration of the interferent.
13. The electrochemical cell of claim 12 wherein the interferent cohabits with the analyte gas.
14. The electrochemical cell of claim 12 wherein the interferent is generated by the counter electrode.
15. The electrochemical cell of claim 12 wherein the electrochemical cell is a gas sensor.
16. The electrochemical cell of claim 15 wherein the analyte is carbon monoxide and the interferent is hydrogen.
17. The electrochemical cell of claim 12 wherein the first reference electrode is positioned to come into contact with minimised concentrations of interferent.
18. The electrochemical cell of claim 12 wherein the second reference electrode is at least partially in direct contact with the analyteinterferent without electrolyte between the second reference electrode and analyteinterferent.
19. A method for designing an electrochemical cell for sensing an analyte in the presence of an interferent, the electrochemical cell comprising a reference electrode and a working electrode connected by a potentiostatic circuit, the analyte reacting at the working electrode giving a first component of current, the interferent undergoing an electrochemical reaction giving a second component of current, the presence at the reference electrode of the interferent leading to a shift in the potential of the reference electrode, wherein the shift in the potential of the reference electrode and the action of the potentiostatic circuit leads to a third component of current, the method comprising the steps of:
selecting the properties of the electrochemical cell which affect the magnitude of the third component of current so that the third component of current acts to partially, completely or over compensate for the second component of current.
20. The method of claim 19 further comprising the step of taking into account interferent which will be produced at the counterelectrode when selecting the properties of the electrochemical cell which affect the magnitude of the third component of current.
21. The method of claim 19 wherein the properties of the electrochemical cell which affect the magnitude of the third component of current and which are selected are one or more of the capacitance of the working electrode, the metal on the reference electrode, the oxidation state of the metal on the reference electrode, the redox couple, capacitance or geometry of the reference electrode.
22. The method of claim 21, for designing a sensor for determining carbon monoxide in the presence of hydrogen.
23. A method for calculating the concentration of an analyte in the presence of an interferent using an electrochemical cell comprising a working electrode and a first reference electrode connected by a potentiostatic circuit and also a second reference electrode, the interferent not affecting the reference electrode thus avoiding a shift in the potential of the reference electrode, the analyte reacting at the working electrode giving a first component of current, the interferent undergoing an electrochemical reaction giving a second component of current, the second reference electrode being configured so as to be exposed to the interferent, the interferent causing a shift in the potential of the second reference electrode, the second reference electrode being connected to the first reference electrode by a potentiometric circuit for providing a measure of the potential difference between the first and second reference electrodes, the method comprising the steps of:
measuring the potential difference between the first and second reference electrodes;
thereby calculating the second component of current; and
thereby providing a measure of the concentration of the analyte which has reduced or no dependency on the concentration of the interferent.
24. The method of claim 23 wherein a measure of the concentration of the analyte is achieved by scaling and substracting the inverse logarithm of the potential difference between the first and second reference electrodes from the total current measured at the working electrode.
25. The method of claim 23 for measuring the concentration of carbon monoxide in the presence of hydrogen.
26. Computer software comprising program code which, when loaded onto a computer, causes it to calculate the concentration of an analyte in the presence of an interferent by the method of claim 23.