Sweep Safe ongoing education series We all love our vacuums but no matter what model, after sucking up lots of fine soot eventually the filters will begin to block or the bag will be full and suction will be lost. Over time there have been some big innovations to dust separation but for some reason us chimney sweeps have missed out on what is available to resolve the issues we know exist. This article focuses on one device that has tremendous benefits to chimney sweeps association and a low cost too. That device is a cyclonic pre separator. A pre separator is a device with a catchment drum that attaches via hoses before the vacuum and thus becomes the first line of defence. The device works by cyclonic action, the vacuum draws air and particles through the device where centrifugal forces separate the soot particles from the air causing them to fall out of solution and into the drum rather than the vacuum container or bag. Why is this good for sweeps? Chimney sweeps utilise the power of their vacuum to control dust while sweeping but as the vac fills up the suction and therefore control over the dust is lost, increasing the risk to the property and user. Some factor manufacturer pre separators boast over 95% efficiency meaning the vast majority of soot will never enter the vac or block the filter or bags. Size and available collection volume. The attached cyclonic container may be much larger than the bag or drum of the vacuum meaning a small powerful vacuum can perform as well or even better than a very large vacuum and actually collect much more dust between emptying and bag changes. There is a massively reduced requirement for both cleaning of the vac itself, the use of expensive bags and changing filters. This reduction in wear and bag use results in lower user costs. Finally some vacuums run hot and even cut out as the filters clog because airflow over the motors is diminished. It is this airflow that cools the. Keeping the filters cleaner for longer results is a vac that can be run for prolonged periods with a lower change of overheating or even damage that may be caused as a result overheating. Due to the volume requirement of the drum traditionally only very large vacuum cleaners were deemed suitable for sweeping many chimneys. The big negatives of using a behemoth of a vac being the associated weight and costs. With a pre separator it is possible to deal with large volumes of soot and without loss of suction. Smaller vacs have grown in favour recently as us sweeps start to age and now that engine design has made them in general far more powerful. Shown in my pictures is pressure relief valve. This valve is important when using larger plastic or even steel drums these can crush under the vacuum force when the hose nozzle is blocked. A small pressure relief or anti crush valve prevents this. Using barrels as shown in the pictures has a huge benefit when sweeping large or commercial chimneys. As they fill you can simple change the lid of a new barrel for the separator, attach a new barrel and carry on sucking away with the soot now safely stowed within a sealed container ready for safe disposal. Furthermore a barrel or drum size can be tailored to fit specific job requirements or even the size of your van or truck.
Thank you all from the sweep safe team. Remember you heard it here first. Sweep safe For safety For the environment For chimney sweeps For the consumer Original Source: Chimney Sweep Association UK
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There are several fuel types available to the solid fuel user, coal, peat, wood logs, compressed wood products, smokeless coals etc. With so much negative info in the press let’s take an objective look which is the right fuel for you to burn. Firstly you must look at your appliance, follow manufacturer guidelines as burning the wrong fuel type can be dangerous and at the very least invalidate your warranty. If your chimney sweep is a registered professional it would pay to listen to them, generally sweeps are a hive of knowledge. If you care about the environment, and you should, then you must focus on renewable fuels such as wood logs. Selecting and purchasing wood logs Ash and beech are some of the best wood logs to burn however most logs burn perfectly well if they are dry enough and have been adequately seasoned. Wood should be purchased from a reputable supplier who will have to comply to regulations and a vested interest in planting more trees to replace what has been felled. Wood logs must have less than 20% water content when they are burned. You can ascertain this several ways the easiest and probably most reliable is to purchase logs approved by Woodsure who will have done all of the eco checks and tested the moisture content in random batches. You will also be able to complain should the wood you purchased have too high a water content. If you chose to purchase unseasoned logs then you must season them (typically for two years or more) after seasoning you must test the moisture content with an electrical conductivity moisture tester prior to using them, if they’re still wet it’s back to the seasoning pile. Again a moisture content of below 20% is required for efficient combustion and to prevent excess soot, increased risk and unnecessary environmental impact. Users burning wet wood is one of the biggest problems and challenges our industry faces however it’s one of the easiest fixes too. Why is mixing fuels a problem? Wood and coal burn quite differently. Wood burns through a process of gasification where the volatile oils within become heated, turn to a gas, mix with oxygen above the log and eventually combust. Coal on the other hand is primarily a carbon burn where oxygen must enter and mix from below the fuel as combustion takes place inside and not above the coal itself There are distinct differences between the two types of appliances Let’s look at some of the issues associated with the incorrect use of fuels 1/ Wood on top of coal If we try to burn wood above a bed of coal we will need to open the top air intake drawing air above the coal and not through it. When this happens the coal which is burning poorly produces high levels of carbon monoxide and carbon dioxide, in doing so our wood gasses which should be bathed in oxygen are now shrouded in the same fire suppressant that is in the black fire extinguishers. The affect is compounded by the adequate heat from the coal, what happens is that the wood pyrolysis in the heat, volatiles hydrocarbons are emitted and become gaseous. Normally these hot gasses mix with oxygen and burn with the yellow flame we associate with wood however in the reduced oxygen environment above a coal bed the volatile gas emitted by the wood log will travel into the chimney where it will deposit as flammable creosote. The final issue when combustion temperatures and oxygen levels are too low is the later hotter stages of gaseous combustion will not effectively take place. During these later phases carbon soot particles should be burned, if they are not they will exit the chimney as fine dust pollution harming our air quality and shortening our lives. 2/ Coal on top of wood We now understand that coal requires oxygen from below to burn effectively, think bellows in a foundry. If we burn wood below a coal bed we will have a situation where our coal is bathed in carbon dioxide leaving an incomplete burn. The second issue here is that wood produces lots of ash which in turn blocks the riddle grate further lowering the amount of available oxygen to the coal. If the coal used is smokeless coal then high levels of sulphurous compounds will also be emitted, these compounds are highly corrosive and will eat through stainless steel liners in no time. The one exception to the wood underneath coal scenario is kindling a fire with wood where it is very likely that the air intakes or even the door will be open in order to provide enough oxygen for both fuels for a limited time. Historically blacksmiths used a bellows to pump air below the coal from under the fire bed. Nowadays they inject neat oxygen or use a pumped fan. Slumbering The term slumbering relates to the user loading the already burning appliance and then closing down the air supply in an attempt to make the fire burn for long periods, typically overnight. There is a huge problem here and that is the fact that fuel requires oxygen for combustion. There are several results that occur when oxygen is limited in a combustion reaction, I’ll list a few.
Ideally you will burn only dry wood logs in an environment that has adequate air for moderate flaming combustion. Adjust the air supply so that flames are not sucking up the chimney but doesn’t limit it too much. Smoke should not be visible in the firebox, only fire.
Add as much fuel as in needed to fill the fire box with flames, burning too much or two little fuel at a given time is another avoidable we can negate. You can ask you profession chimney sweeps for tips on fuels and how to achieve moderate flaming combustion, fuel storage, type, sweeping frequencies and many other important factors surrounding burning practices. Sweep Safe For safety For the environment For chimney sweeps For the consumer Original Source:- Chimney sweep association UK Once you own a wood burning stove you become responsible to ensure it works safely, burns cleanly and lasts a long time. Unfortunately, many stove owners are unaware of the basic requirements needed to ensure it all keeps working. Stove maintenance can be broken down into three distinct sections. Much of the daily maintenance can be handled by the home owner but some of the more complex maintenance will require professional help 1/ Daily / weekly / monthly maintenance, chimney sweeping and stove servicing. at regular intervals. These are mostly straight forward, once you get used to them: Ensure the stove is cold with no burning embers before undertaking any of the below.
2/ Chimney sweeping The sweeping of the chimney is imperative to the correct and safe functioning of the appliance. In our opinion Chimneys should only be swept by registered professionals. Chimney Sweeping is a profession that requires a great deal of knowledge, equipment and chimney sweep training at regular intervals. It is widely accepted that all chimneys should be swept annually as a minimum. Some chimneys require sweeping twice per year some even more frequently depending on use, safety factors and soot build up. A professional chimney sweep will also provide important advice, and confirm with you the required sweeping frequency for your usage, which will be backed up on an official sweeping certificate. Further to cleaning the flue the Sweep must smoke test the flue/appliance to ensure the safe release of flue gasses to the outside air, thus protecting the user from potential risks from or property damage. Your sweep should also check many other safety related issues such as; ventilation, distances to combustibles, fuel storage, carbon monoxide alarms and many other such things. 3/ Solid fuel servicing Solid fuel servicing is often an unknown variable when people purchase stoves and similar appliances. Yes it’s true that many stoves can last a very long time but their internal components often do not. The internal stones and grates of an appliance are designed to survive the rigours of use however they do decay, wear and occasionally break. Repeated opening and closing of doors degrades rope seals which will eventually require replacing. Door Glass can be broken but more often becomes scratched or milky with use, replacing glass is not as straightforward as replacing the glass of a house window. The glass used in stoves is often a clear pyro ceramic which is held in place with heat proof fixings and sealed with a specially sized fibre glass rope. It is specially treated and pre-cut with bevelled or smooth edges to prevent early failure. Controls and hinges can become lose or siege with time. Castings can even crack. The best person to use for solid fuel servicing is a professional chimney sweep certified by any Chimney sweep associationor Hetas registered installer who is also trained and experienced in service and maintenance. The HETAS H009 is the de facto qualification in the U.K. for this type of work although those who hold the H003 will also in many instances be competent to undertake this work. Experience is very important when servicing is involved as there are so many appliances only time and practice can teach. Many users find it most beneficial to find a professional sweep who also undertakes servicing. This can save time and money. There are some huge possible risks to the stove user who avoids or neglects the necessary maintenance and sweeping intervals:
If you are unsure of what you must do yourself then call a local approved chimney sweep and ask advice. Although the advice in this post is good it is not specific to your particular appliance. You must take professional advise specific to your particular installation and follow the guidelines set out by the appliance manufacturer and your home insurance company. Sweep Safe For safety For the environment For chimney sweeps For the consumer |
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January 2020
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