64 results about "Photoionization detector" patented technology

The present invention discloses a method and a treatment system for restoring organic pollution soil through combination of room temperature desorption and chemical oxidation. The method comprises: placing organic matter polluted soil in a room temperature desorption workshop; adopting a moveable soil turner to turn the polluted soil, wherein one turning is performed every 2 h, a portable photoionization detector is adopted to rapidly detect the concentration of volatile or semi-volatile organic matters at a position above 15-25 cm of the polluted soil during a turning process, and turning is stopped until the detection data is stabilized; and adding a 6% potassium permanganate solution to a liquid tank, opening a water pump and a manual control valve, spraying the potassium permanganate solution to the polluted soil, concurrently adopting the soil turner to uniformly turn the potassium permanganate solution and the polluted soil, and stopping spraying and turning until the potassium permanganate content in the soil achieves the preset addition amount. The present invention further provides a treatment system for the method. With the method, organic pollutant soil restoring efficiency is high, the cost is low, and the method is a combination restoring method with strong practicability in the project.

The invention relates to a chromatographic photoionization detector which comprises a tail blowing connector and a nozzle, wherein the tail blowing connector is arranged on a chromatographic connecting column connected with a chromatographic column and used for preventing the peak of a sample curve to be detected from widening or trailing; the nozzle is embedded into an ionization chamber and taken as an electrode to be connected with a collector connector through a probe to realize transmission and acquisition of voltage signals; the ionization chamber is provided with two air passages, wherein one is an exhaust port through which the residual gas in the detecting course is exhausted, and the other one is a curtain exhaust port and is used for blowing and cleaning the window of an ultraviolet lamp in the detecting course; the ionization chamber is connected with the fixed sleeve of the lamp through screw threads; the fixed sleeve of the lamp is tightly pressed with a lamp pressing sleeve embedded with the base of the ultraviolet lamp; the protective cover of the lamp is tightly pressed and sheathed with the ultraviolet lamp through the pressing spring of the lamp; and the ultraviolet lamp activates a voltage lead joint to be fixedly connected to the protective cover of the lamp through a tacking nut. The chromatographic photoionization detector improves the insufficient design of the conventional chromatographic photoionization detector and enhances the sensitivity, selectivity and stability of a PID (Proportion Integration Differentiation) detector.

The invention relates to a pollution VOC concentration and total discharge amount real-time monitoring system. The system comprises a exhaust gas sampling unit, an exhaust gas pretreatment unit, a VOC detection unit, an exhaust gas parameter measuring unit, a data processing unit, a back flushing unit, a calibration unit, a communication unit and a central control unit; an output of the exhaust gas sampling unit is connected with the VOC detection unit through the exhaust gas pretreatment unit, both the exhaust gas parameter measuring unit and an output of the VOC detection unit are connected with the data processing unit, an output of the data processing unit is connected with the communication unit, the back flushing unit and the calibration unit, and the communication unit and the central control unit perform data transmission in a wireless mode or a wired mode. The pollution VOC concentration and total discharge amount real-time monitoring system provided by the invention adopts a photoionization detector to detect the concentration and the total amount of particular pollutants discharged by a pollution discharge enterprise, thereby performing real-time monitoring of the concentration and the total discharge amount of VOC. Various compounds including aromatics, ketones, aldehydes, alcohols, ammonia and amines, halogenated hydrocarbons, sulphohydrocarbons, unsaturated hydrocarbons and the like are detected.

An auto-cleaning and auto-zeroing system (1) comprises a first conduit for flow of ambient gas (16) and a 2^nd conduit (22) for flow of ambient air (18). A cleaning chamber (12) removes impurities from ambient air (18). The 1^st conduit (20) and 2^nd conduit (22) are connected to a valve, operated by the continuous motor, which continuously draws ambient gas (16) or cleaned and filtered ambient air (18) through the system. Cleaned and filtered ambient air (18) enters the ionization chamber (10) to carry out a cleaning (flushing) and a cleaning (ionization) cycle. In this manner, contaminants and pollutants left in the ionization chamber (10) from the measurement of ambient gas (16) are flushed out and removed.

The invention discloses an SCR (selective catalytic reduction) denitration system control method for preventing urea from being excessively sprayed. The method comprises the following steps: step 1, detecting nitrogen oxide concentration at a gas outlet, entering a PID (photoionization detector) mode if the value of the concentration is less than a set value, or else entering step 2; step 2, controlling a spraying speed of the urea, enabling the spraying speed to increase along with the increase of time, detecting the nitrogen oxide concentration at the gas outlet, entering the PID mode if thenitrogen oxide concentration is reduced along with the increase of time, or else entering step 3; step 3, reducing urea spraying speed, detecting the nitrogen oxide concentration at the gas outlet until the nitrogen oxide concentration is less than the set value of the concentration, and then entering the PID mode. By open-loop control and closed-loop PID mode combination control, the excessive spraying state of the urea can be corrected, so that the control mode can always be controlled towards a set minimum nitrogen oxide concentration direction, and the nitrogen oxide concentration is prevented from continuously abnormally rising.

The embodiment of the invention provides a volatile organic compound monitoring method and system. The problems that in the prior art, when VOCS are detected through gas chromatography, the great limitation exists, and the application range is limited are solved. The volatile organic compound monitoring method comprises the steps that the to-be-detected gas is sampled to obtain sampled gas, and the sampled gas is pretreated; the pretreated sampled gas is fed into a detection device; qualitative analysis is performed on the pretreated sampled gas through a gas chromatograph in the detection device to obtain qualitative analysis data; quantitative analysis is performed on the pretreated sampled gas through a photoionization detector in the detection device to obtain quantitative analysis data; gas components included in the pretreated sampled gas and the concentrations of all the gas components are calculated by a processor according to the qualitative analysis data and the quantitative analysis data. According to the volatile organic compound monitoring method and system, the monitoring efficiency and reliability can be improved, and application and popularization are easy.

The present invention provides a mass spectrometer comprising a sample inlet, an ionization source, a mass analyzer, and an ion detector, wherein the ionization source comprises a photoionization detector lamp. The invention also provides mass spectrometers comprising two photoionization detector lamps. The use of a photoionization detector lamp can provide an increase in the signal of detected compounds as compared to the signal of detected compounds obtained using a comparable mass spectrometer with a conventional electron pumped beam lamp.

The invention discloses a pretreatment device for a miniature two-dimensional chromatograph and a working method thereof. The device is technically characterized by comprising a power supply subassembly, a miniature water removal cold trap and an enrichment thermal analyzer sampling system, wherein the enrichment thermal analyzer sampling system comprises chromatographic columns on two side surfaces of a bearing box; one side of each of the chromatographic columns is provided with a quartz adsorption tube; one side of the quartz adsorption tube is provided with a spiral first heating resistance wire; the device further comprises a main cooling plate located at an exterior of the first heating resistance wire; the device further comprises a two-dimensional chromatographic column temperaturecontrol box; the two-dimensional chromatographic column temperature control box comprises a heat dissipation base; the chromatographic columns are disposed on the heat dissipation base; second heating resistance wires are wrapped on outer walls of the chromatographic columns; heat insulation sleeves are connected to an upper part of the heat dissipation base in an insertion manner; and the devicefurther comprises a stop-flow modulator and a miniature photoionization detector. According to the pretreatment device for the miniature two-dimensional chromatograph and the working method thereof disclosed by the invention, through water-removal treatment and refrigeration enrichment adsorption treatment, an adsorption component is rapidly heated and released, a detected component is separatedby the two-dimensional chromatographic columns under different temperature gradients and is detected by the miniature photoionization detector to form a two-dimensional chromatogram.

The invention relates to the technical field of environment engineering, and especially relates to an analytical method for preliminary sampling of site environment. The soil gas collected in the field is used to carry out on-site monitoring through soil gas sampling apertures with on-site arrangement, a pollution evaluation index value PI is obtained by a portable photoionization detector (PID),and the organic pollution level of the site can be classified. The organically contaminated soil can be quickly determined at different sites and temperatures, which is suitable for sites contaminatedby volatile organic compounds; in addition, the on-line monitoring of the river mud surge sediment treatment provided by the present invention monitors the pollutant concentration of the contaminatedsediment in a discharge pipeline obtained by the real-time monitoring of the river lake, and whether the pollutant concentration reaches a preset concentration value or not can be determined, on-linereal-time monitoring and identification control of contaminated sediments can be realized, and intelligent judgment and automated efficient treatment of contaminated sediment digging can be realized.

The invention provides a PID (photoionization detector). The PID comprises an ultraviolet lamp, an ionization chamber, an analyzed gas inlet pipe inserted into one side of the ionization chamber and an analyzed gas discharging pipe inserted into the other side of the ionization chamber, wherein the lower part of the ultraviolet lamp is inserted into the upper part of the ionization chamber, and analyzed gas enters the ionization chamber via the analyzed gas inlet pipe and ionized under irradiation of ultraviolet light, produces current for data acquisition under the action of an electric fieldin the ionization chamber and is discharged from the analyzed gas discharging pipe. A purge gas inlet pipe is inserted into the lower part of the ionization chamber, so that a gas outlet of the purgegas inlet pipe is located under a window of the ultraviolet lamp, the window of the ultraviolet lamp is uniformly and symmetrically purged and cleaned, and accordingly, the service life of the ultraviolet lamp can be effectively prolonged. Through reduction of the sizes and distances of electrodes in the ionization chamber, the volume of the ionization zone can be reduced, and the sensitivity ofthe detector is improved.