search.noResults

search.searching

dataCollection.invalidEmail
note.createNoteMessage

search.noResults

search.searching

orderForm.title

orderForm.productCode
orderForm.description
orderForm.quantity
orderForm.itemPrice
orderForm.price
orderForm.totalPrice
orderForm.deliveryDetails.billingAddress
orderForm.deliveryDetails.deliveryAddress
orderForm.noItems
Annual Guide 2019 I SOURCE TESTING ASSOCIATION


and again the vacuum pulls the fi lter together. In both cases if a leak suddenly disappears then be careful because it can reappear just as easily and often at the end of a really gruelling day! Always investigate self-sealing leaks; they are just problems waiting to happen.


How should nozzles be sealed for the leak check? Only use clean powder free nitrile gloves or a new rubber teat from a Pasteur pipette for smaller nozzles. These both work well and are easily removed to release the vacuum. Fingers or other materials are generally poor and can lead to contamination especially where chemical analysis is required. I normally wrap a glove around the nozzle as this is less painful to the fi nger. Never start to release a vacuum and then reseal it once the pump is off; if there is still a vacuum in the glass train then a suck back can occur and solutions/water can be sucked into the further back impinger.


The other problem often encountered is port adapters as ports are frequently corroded and of varying specifi cations. One needs care in inserting the probe both to achieve a gas tight seal and to ensure safety of the team. Flanged ports are more satisfactory to the installation of quality port adapters than 4 or 5” BSP Sockets.


seal and to ensure safety of the team. Flanged ports are more satisfactory to of quality port adapters than 4 or 5” BSP Sockets.


If we are sampling externally we need to have the hot box and probe thor equilibrated. Most systems have PID controllers, though they may need prevent different probes overshooting temperature dramatically. There is a between a 1.5m probe and a 4m probe in heating characteristics.


If we are sampling externally we need to have the hot box and probe thoroughly hot and equilibrated. Most systems have PID controllers, though they may need auto-tuning to prevent different probes overshooting temperature dramatically. There is a big difference between a 1.5m probe and a 4m probe in heating characteristics.


Finally, when you start


Be careful when conducting leak tests that you do not use the sample train as a vacuum cleaner. On one audit the sample team had high levels of dioxins/furans and the regulators wanted a series of repeat tests. When the teams were audited the site was found to be fi lthy with a lot of extraneous dust around the ports. The team also had a habit of running the pump continuously as they conducted the leak checks, so it was easily possible to ingest dust into the sample train. This dust when collected and tested was found to have high levels of dioxins, whilst the plant with a state-of-the-art abatement system was clean.


There are two other problems which attempt to confound stack samplers: using too fi ne a grade silica gel in the fi nal impinger which then clogs the Modifi ed GS Impinger or using the new and very tempting ball bearing type silica gel. This latter silica gel looks great but manages to form a tightly and closely packed set of balls in the impinger stem and then when slightly damp expands to block or restrict fl ow or break the jet. Always use coarse irregular shaped silica gel and don’t regenerate it as it becomes fi ner and fi ner. The fi ne dust then migrates to the gas meter, killing it stone dead. Don’t ruin the gas meter for a ha’p’orth of tar … or silica gel for that matter.


Broken impinger stems are impossible to clean properly and can lead to contamination problems. They can have cracks which can propagate and cause issues and affect personal safety. They have usually been cracked through pushing roughly into silica gel. This can lead to contamination of samples if used in a different position in the train on another occasion, and broken impingers don’t scrub gas effi ciently and can lead to absorption effi ciency problems.


The key to a successful test is looking after your equipment as it will then look after you!


Conducting a Test When all this is done you are in good shape to fi nally start the test.


A good test is often compromised by not cleaning out the ports thoroughly and thereby ingesting dust from these into the nozzle. When limits were high this was not too much of a problem but now at 2 to 10 mg/Nm3


limits, stray dust can be an issue.


Method 5 System Super Probe and Monorail using a High Tempe Introduction Port


Method 5 System Super Probe and Monorail using a High Temperature/Velocity Introduction Port


At the end of the test remember to note down the final readings and time w completed. Many a good test has been compromised by the exuberance of fi and forgetting to record the last data point. This is especially true as the rain the back of your neck and your dinner beckons.


Quality Control and Assurance


At the end of the test remember to note down the fi nal readings and time when the test is completed. Many a good test has been compromised by the exuberance of fi nishing the test and forgetting to record the last data point. This is especially true as the rain dribbles down the back of your neck and your dinner beckons.


The US EPA Method 5 train relies heavily on having a calibrated orifice pate by setting the ΔH across it when applying a vacuum. It is on the basis of this of it being relatively insensitive over a range of normal flows which allows a Δ sampling. The orifice is typically a simple washer welded into the exit pipe of


9


Finally, when you start testing ensure that the start time and gas meter readings are recorded, even with automatic samplers. It is not unheard of for these to lose vital data. testing ensure that


recorded, even with automatic samplers. It is not unheard of for these to lose


The flow rate needs to be adjusted quickly when each sample traverse point enable this


various stack gas parameters need recording, and the isokinet


The fl ow rate needs to be adjusted quickly when each sample traverse point is reached. To enable this, various stack gas parameters need recording and the isokinetic rate modifi ed for each point. But how do you safely deploy a Method 5 or out-of- stack fi lter sample train?


the start


Moving a long and heavy probe to each position within a few millimetres position is not an easy task. In India I once saw a modified tea trolley with a and rails used with a 4m probe and a glass nozzle, not a very satisfactory ar a good way to lose expensive glass nozzles. Laboratory jacks and workmat but the only proper way is to use a monorail system. This is how a Method 5 designed to be deployed and everything else is a compromise.


Moving a long and heavy probe to each position within a few millimetres of the desired position is not an easy task. In India I once saw a modifi ed tea trolley with a laboratory jack and rails used with a 4m probe and a glass nozzle, not a very satisfactory arrangement and a good way to lose expensive glass nozzles. Laboratory jacks and workmates can be used but the only proper way is to use a monorail system. This is how a Method 5 type train was designed to be deployed and everything else is a compromise.


for each point. But how do you safely deploy a Method 5 or out-of-stack filter s time and gas mete


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88  |  Page 89  |  Page 90  |  Page 91  |  Page 92  |  Page 93  |  Page 94  |  Page 95  |  Page 96  |  Page 97  |  Page 98  |  Page 99  |  Page 100  |  Page 101  |  Page 102  |  Page 103  |  Page 104  |  Page 105  |  Page 106  |  Page 107  |  Page 108