Background technology
VOC is the english abbreviation of volatile organic compounds (Volatile Organic Compounds), common meaning
On VOC refer to volatile organic matter, and the VOC on environment protection significance refers to active a kind of volatile organic matter, i.e., can generate
That a kind of volatile organic matter of harm.
VOC has tremendous influence to health.When the VOC in room reaches a certain concentration, people are in the short time
Inside just it is present with the symptoms such as headache, Nausea and vomiting, weak, can also twitches or go into a coma when serious.VOC can hurt people liver,
Kidney, brain and nervous system cause the serious consequences such as failure of memory.
VOC still forms the important sources of PM2.5, it is estimated that China's VOC emission amount is about on 2000 to 3,000 ten thousand tons of left sides
Therefore the right side, in order to improve environmental quality, controls the discharge of VOC, be an imperative job.
Substantial amounts of VOC gas are discharged in China's industrial processes, the density and gross volume of such pollutants to be discharged of such gas are examined
It surveys and control is particularly significant and necessary, and need to sample VOC gas before testing.At present, carried out to VOC
During sampling, be all directly using pipeline directly by sampling head and Soviet Union's agate tank or gas cylinder, before sampling can not signal piping whether have
There is the situation of leakage.
Utility model content
The technical problem to be solved by the present invention is to provide one kind can before sampling to sampling head and Soviet Union agate tank it
Between gas circuit test the gas circuit structure and VOC for VOC samplings of leakage and keep sample instrument.
In order to solve the above technical problems, the utility model offer technical solution is as follows:
A kind of gas circuit structure for VOC samplings, including sequentially connected solenoid valve, pipe fitting and valve, the valve
Import be also associated with the pressure sensor and booster pump being connected in parallel with each other, the outlet of the valve is for connecting Soviet Union's agate tank
Import, the import of the solenoid valve are used to connect the outlet of sampling head.
Further, the pipe fitting include with the solenoid valve outlet connection the first three-way connection and with it is described
Second three-way connection of the one outlet connection of the first three-way connection, another of first three-way connection are exported described in connection
Booster pump, the one outlet of second three-way connection connect the import of the valve, another outlet connects the pressure and passes
Sensor.
Further, the pipe fitting is four-way connection, and the import of the four-way connection connects the outlet of the solenoid valve,
Three outlets of the four-way connection connect the valve, pressure sensor and booster pump respectively.
Further, mechanical valve group is also associated between the pipe fitting and booster pump.
Further, it is also associated with mass flowmenter between the solenoid valve and pipe fitting.
Further, the import of the solenoid valve is connected with film support, and the import of the film support is used to connect going out for sampling head
Mouthful, the film support is made of filter membrane.
Further, the filter membrane is polytetrafluoroethylene diaphragm.
Further, the valve is six-way valve or four-way valve.
Further, connected between the solenoid valve, pipe fitting, pressure sensor and booster pump using polyfluortetraethylene pipe
It connects, is connected between the import of the pipe fitting, valve and agate tank of reviving using coating stainless steel tube.
A kind of VOC keeps sample instrument, including any of the above-described gas circuit structure for VOC samplings.
Compared with prior art, the utility model has the advantages that:
The gas circuit structure and VOC for VOC samplings of the utility model keeps sample instrument in the outlet of sampling head and agate tank of reviving
The devices such as solenoid valve, booster pump, pressure sensor and valve between import are set, by booster pump the sealing of pipeline are examined to let out
Dew situation.It is as follows that it tests leakage method:After the gas circuit structure for VOC samplings of the utility model connects, it is first shut off
The valve of solenoid valve and Su Ma tanks, it is 14.7psi to read the numerical value that pressure sensor detects at this time;Booster pump is opened afterwards,
The gas in pipeline is extracted, booster pump is closed after the hypotension in pipeline to 6~7psi, pipe is checked after 1~2min of timing
Whether the pressure value (numerical value that pressure sensor detects) on road changes, if the variation of the pressure value of pipeline is within 2%
(include 2%), then pipeline No leakage, the good airproof performance of pipeline;If the pressure value rise of pipeline, then have leak in pipeline,
At this moment each device in pipeline can be investigated and solved according to checkout sequence, repeated the above steps afterwards, until pipe
In road until No leakage.The gas circuit structure for VOC samplings of the utility model is simple, and it is easy to operate to test leakage mode.
Specific embodiment
In order to make the technical problems, technical solutions and advantages to be solved by the utility model clearer, below in conjunction with attached drawing
And specific embodiment is described in detail.
On the one hand, the utility model provides a kind of gas circuit structure for VOC samplings, as shown in Figure 1, including being sequentially connected
Solenoid valve 3, pipe fitting 5 and valve 9, the import of valve 9 is also associated with the pressure sensor being connected in parallel with each other 6 and booster pump
8, for connecting the import of Soviet Union's agate tank 10, the import of solenoid valve 3 is used to connect the outlet of sampling head 1 for the outlet of valve 9.
The gas circuit structure for VOC samplings of the utility model is set between the outlet of sampling head and the import of Soviet Union's agate tank
The devices such as solenoid valve 3, pressure sensor 6, booster pump 7 and valve 9 examine the seal leakage situation of pipeline by booster pump 7.
It is as follows that it tests leakage method:After the gas circuit structure for VOC samplings of the utility model connects, solenoid valve 3 is first shut off
With the valve for agate tank 10 of reviving, it is 14.7psi to read the numerical value that pressure sensor 6 detects at this time;Booster pump 8 is opened afterwards, is taken out
The gas in pipeline is taken, booster pump is closed after the hypotension in pipeline to 6~7psi, pipeline is checked after 1~2min of timing
Pressure value (numerical value that pressure sensor 6 detects) whether change, if the variation of the pressure value of pipeline is within 2%
(include 2%), then pipeline No leakage, the good airproof performance of pipeline;If the pressure value rise of pipeline, then have leak in pipeline,
At this moment each device in pipeline can be investigated and solved according to checkout sequence, repeated the above steps afterwards, until pipe
In road until No leakage.The gas circuit structure for VOC samplings of the utility model is simple, and it is easy to operate to test leakage mode.
Wherein, solenoid valve 3 can be two-port valve, generate magnetic force by switch electricity to open and close solenoid valve, solenoid valve 3
Play the role of switching sample feeding mouth.
In the utility model, in order to which pressure sensor 6 and booster pump 8 is made to be connected in parallel to the import of valve 9, pipe fitting 5
Two three-way connections may be employed to be connected in series, i.e., pipe fitting 5 preferably includes to connect with the 1st of the outlet connection of solenoid valve 3
Head 5-1 and the second three-way connection 5-2 being connected with the one outlet of the first three-way connection 5-1, the first three-way connection 5-1's is another
One outlet connects booster pump 8, the import of the one outlet connecting valve 9 of the second three-way connection 5-2, another outlet connection pressure
Force snesor 6.
In addition, pipe fitting 5 can also be a four-way connection, and the outlet of the import connection solenoid valve 3 of four-way connection, four-way
Three outlet difference connecting valves 9, pressure sensor 6 and the booster pump 8 of connector.
Preferably, mechanical valve group 7 can also be connected between pipe fitting 5 and booster pump 8.Mechanical valve group 7 can be by independence
TOV valves and mechanical switch composition, the opening and closing of TOV valves are controlled by being powered or powering off to mechanical switch, with control
Connection and disconnection between gas piping and booster pump 8, the negative-pressure sealing of TOV valves is preferable, can avoid the sealing of itself
Property leakproofness that is poor and influencing entire pipeline.
In gas sampling process, gas flow rate is controlled in order to realize, may be used also between solenoid valve 3 and pipe fitting 5
To be connected with mass flowmenter 4.Mass flowmenter 4 can accurately control gas according to required sampling time and sampling tank volume
Flow velocity in pipeline.
According to fluid velocity calculation formula v=V/t, wherein, v represents fluid flow rate, and V represents sampling tank volume, and t expressions are adopted
The sample time.For example, using the utility model for VOC keep sample the gas circuit structure of instrument sampled when, to Soviet Union's agate tank of 3.2L
It is sampled, when the sampling time is 10 small, then sample flow rate can be automatically regulated to be by mass flowmenter 4:
V=V/t=3.2L/10H=0.32L/H=5.3ml/min.
In order to further be filtered to impurity such as the in vivo dust of gas before entering pipeline, the import of solenoid valve 3
It is preferred that being connected with film support 2, the import of film support 2 is used to connect the outlet of sampling head 1, and film support 2 is preferably made of filter membrane.Its
In, filter membrane is preferably polytetrafluoroethylene diaphragm.Polytetrafluoroethylene diaphragm has fabulous sealing performance, and cost is relatively low.
In addition, in order to be sampled simultaneously into multiple Soviet Union's agate tanks 10, valve 9 can be six-way valve or four-way valve.Work as valve
It when door 9 is six-way valve, can at most be sampled simultaneously into 5 Soviet Union's agate tanks, the present embodiment is using six-way valve simultaneously to 4 Soviet Union's agate tanks
Interior sampling.When valve 9 is four-way valve, can at most be sampled simultaneously into 3 Soviet Union's agate tanks.
Preferably, polyfluortetraethylene pipe may be employed between solenoid valve 3, pipe fitting 5, pressure sensor 6 and booster pump 8
The connection of coating stainless steel tube may be employed in connection between the import of pipe fitting 6, valve 9 and Soviet Union's agate tank 10.In gas circuit structure
In actual connection, according to the layout scenarios of each device suitable hose or hard tube can be selected to be attached.
On the other hand, the utility model also provides a kind of VOC and keeps sample instrument, including any of the above-described gas for VOC samplings
Line structure.
The VOC of the utility model keep sample instrument sampling head outlet revive agate tank import between set solenoid valve 3, pressure
The devices such as sensor 6, booster pump 7 and valve 9 examine the seal leakage situation of pipeline by booster pump 7.It tests leakage method such as
Under:After gas circuit structure of the utility model for VOC samplings connects, solenoid valve 3 and Su Ma tanks 10 are first shut off
Valve, it is 14.7psi to read the numerical value that pressure sensor 6 detects at this time;Booster pump 8 is opened afterwards, extracts the gas in pipeline
Body closes booster pump after the hypotension in pipeline to 6~7psi, and the pressure value (pressure of pipeline is checked after 1~2min of timing
The numerical value that sensor inspection 6 measures) whether change, if the variation of the pressure value of pipeline (includes 2%) within 2%, then manage
Road No leakage, the good airproof performance of pipeline;If the pressure value rise of pipeline, then have leak in pipeline, at this moment can be according to inspection
It tests order each device in pipeline is investigated and solved, repeat the above steps afterwards, until No leakage in pipeline.
The gas circuit structure that the VOC of the utility model keeps sample in instrument is simple, and it is easy to operate to test leakage mode.
The above is the preferred embodiment of the utility model, it is noted that for the ordinary skill of the art
For personnel, on the premise of principle described in the utility model is not departed from, several improvements and modifications can also be made, these improvement
The scope of protection of the utility model is also should be regarded as with retouching.