High-temperature condensation particle counter
Various embodiments include an exemplary design of a high-temperature condensation particle counter (HT-CPC) having particle-counting statistics that are greatly improved over prior art systems since the sample flow of the disclosed HT-CPC is at least eight times greater than the prior art systems. In one embodiment, the HT-CPC includes a saturator block to accept directly a sampled particle-laden gas flow, a condenser block located downstream and in fluid communication with the saturator block, an optics block located downstream and in fluid communication with the condenser block, and a makeup-flow block having a concentric-tube design located in fluid communication with and between the condenser block and the optics block. The makeup-flow block being configured to reduce volatile contents from re-nucleating in the optics block. Other designs and apparatuses are disclosed.
1. A high-temperature condensation particle counter (HT-CPC), comprising:
a saturator block configured to accept directly a sampled particle-laden gas flow;
a condenser block located downstream and in fluid communication with the saturator block;
an optics block located downstream and in fluid communication with the condenser block;
a makeup-flow block located in fluid communication with and between the condenser block and the optics block; and
a particle-free gas supply coupled to the makeup-flow block and configured to supply a makeup gas-flow that is substantially free of particles, the particle-free gas supply comprising at least three sections including a make-up gas-supply section, a curtain-flow gas-supply section, and a recirculation gas-supply section.
2. The HT-CPC of claim 1 , wherein a temperature of the makeup gas-flow is at about ambient room temperature.
3. The HT-CPC of claim 1 , wherein a temperature of the makeup gas-flow is at about a temperature substantially lower than the condenser temperature.
4. The HT-CPC of claim 1 , wherein the particle-free gas supply is configured to:
keep gases flowing into the optics block below a temperature of gases leaving the condenser block;
dilute excess working fluid vapors and condensable vapors from the gases leaving the condenser block to reduce the vapors from re-nucleating within the optics block; and
supplement a volumetric flowrate of the sample particle-laden gas flow to maintain an optics gas flowrate at a desired level.
5. The HT-CPC of claim 1 , wherein the recirculation gas-supply section is configured to remove excess gas from an output of the optics block to feed gas to the make-up gas-supply section and the curtain-flow gas-supply section.
6. The HT-CPC of claim 1 , wherein the make-up flow block comprises a concentric-tube design.
7. The HT-CPC of claim 6 , wherein the concentric-tube design of the makeup-flow block is configured to keeps particles from the sampled particle-laden gas flow near a centerline of a flow path in the optics block.
8. A high-temperature condensation particle counter (HT-CPC), comprising:
a saturator block configured to accept directly a sampled particle-laden gas flow;
a condenser block located downstream and in fluid communication with the saturator block;
an optics block located downstream and in fluid communication with the condenser block;
a makeup-flow block located in fluid communication with and between the condenser block and the optics block;
a particle-free gas supply coupled to the makeup-flow block and configured to supply a makeup gas-flow that is substantially free of particles; and
a curtain-flow device in fluid communication with both the particle-free gas supply and the optics block to feed a substantially particle-free gas into the optics block to reduce an amount of particulate contamination and vapor contamination on optical elements within the optics block.
9. The HT-CPC of claim 8 , further comprising heaters coupled to the saturator block and to the condenser block to provide heat to maintain a temperature of the saturator block and the condenser block of at least about 200° C. and at least about 160° C., respectively.
10. The HT-CPC of claim 9 , wherein the heaters comprise mica heaters.
11. The HT-CPC of claim 9 , further comprising at least one proportional-integral-derivative (PID) controller to control the heaters.
12. The HT-CPC of claim 8 , wherein the make-up flow block comprises a concentric-tube design.
13. The HT-CPC of claim 12 , wherein the concentric-tube design of the makeup-flow block is configured to keeps particles from the sampled particle-laden gas flow near a centerline of a flow path in the optics block.