Backflush-cleanable and fast-calibration gas detection probe with multi-phase catalyst alloy, far-infrared and negative ion ceramic filters

Abstract

The gas detection probe adopting multi-phase catalyst alloy and far-infrared ceramic filter, which can be backwashed and quickly calibrated, belongs to the field of safety protection, and is quite suitable for catalytic combustion and semiconductor gas sensors. Its filtering ability is not affected by humidity, its absorption rate to the measured gas is very small, and its service life is long. The "∏" shaped porous polytetrafluoroethylene core shell and the porous multi-phase catalyst alloy, negative ion and far-infrared ceramic catalyst assembly inside it are the core components of the invention. The former is water-repellent and non-wetting to most solvents, and the latter uses porous ceramic catalyst components to have irreversible adsorption and high activity for sulfur-silicon-based gases, but has no reactivity for hydrogen, alkanes and carbon monoxide. Does not adsorb. Therefore, sulfur-silicon-based interfering gases can be efficiently filtered out. Its standard gas input and back blowing pipe parts for gas cleaning bring great convenience to gas sensor calibration and back blow cleaning, and are beneficial to prolonging its service life.

Description

technical field [0001] The invention relates to a gas detection probe which adopts a multi-phase catalyst alloy, far-infrared and negative ion ceramic filter, which can be backwashed and quickly calibrated, in particular to a porous multi-phase catalyst alloy, far-infrared and negative ion ceramic catalyst Filters (such as hydrogen sulfide, sulfur dioxide, organic silicon such as hexamethylsilane (HMDS), etc.) and high-resolution, high-stable flammability that can be backwashed and quickly calibrated as key components Or a toxic gas detection probe, which belongs to the technical field of safety protection. The gas detection probe using multi-phase catalyst alloy, far infrared and negative ion ceramic catalyst filter is quite suitable for use in catalytic combustion type gas sensor, semiconductor ceramic type gas sensor, constant potential electrolytic type electrochemical gas sensor, Galvani type Electrochemical gas sensors and other types of gas sensors. It has an obvious ...

AI Technical Summary

Problems solved by technology

[0002] At present, the selectivity of most gas sensors in the world cannot fully meet the requirements of various industries, especially in the resistance to interference gases such as hydrogen sulfide, sulfur dioxide, and organosilicon such as hexamethylsilane (HMDS). Technical flaws:

If the gas alarm does not have a filter protection device, as long as the air contains less than 1ppm of hexamethylsilane, the gas alarm will only work for a few seconds in the atmosphere, and its sensitivity will drop significantly

In addition, the current structure still cannot realize the backflush cleaning and quick calibration of the pollutants on the filter surface, and its operability is not good

[0009] Activated carbon is a conventional filter material at present, but unfortunately it has the following three disadvantages: (1) Activated carbon has no selectivity for the filtration effect of gas, in other words, it has the ability to filter out hydrogen sulfide, sulfur dioxide, and hexamethylsilane. At the same time, it also performs a certain degree of "adsorption" and "attenuation" on the monitored gases (such as methane, isobutane, carbon monoxide, hydrogen, etc.)

(2) The effective filtration pore size of activated carbon depends on the temperature and humidity of the environment, so the relationship between its filtration characteristics and environmental parameters is a multivariate function curve with a large uncertainty

(3) The adsorption of activated carbon molecules is a reversible physical adsorption mechanism, so its filtration capacity is short-lived and easily saturated

After saturation, desorption occurs, the activated carbon loses its adsorption capacity, and its life is short. It needs to be regenerated or replaced with fresh activated carbon.

Clearly, activated carbon is not ideal as a filter material for gas detection probes

[0010] In short, the current status is that most gas detection probes and gas alarms have a weak ability to filter out interfering gases (such as hydrogen sulfide, sulfur dioxide, organic silicon such as hexamethylsilane, etc.). The resistance to harmful gases is quite low, and the characteristics of water repellency and high humidity resistance are not good, which can no longer meet the requirements of many departments. Some foreign countries with advanced technology have included the filtering and suppression requirements for the above-mentioned interfering gases in their own industries. Standard or national standard, and our country is brewing

In a word, the main disadvantage of most domestic and foreign gas detection probes and gas alarms is the ability to filter out interfering gases (such as hydrogen sulfide, sulfur dioxide, organic silicon such as hexamethylsilane, etc.) Insufficient, lacks water repellency and high humidity resistance, cannot or is not convenient for backflush cleaning and quick calibration, poor operability

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