Radiant Floor Heating For Comfort And Efficiency By Alex Parry

Radiant floor heating is an efficient and comfortable way to heat your home. It provides superior comfort to compared forced air heating because the heat emanates from the floor, and rises. The air cools somewhat as it rises. This allows the temperature at the feet and legs to be slightly warmer than the temperature in the air around the head.

Radiant heat is produced from either hot water flowing through a pipe system in the floor (hydronic), or by electricity. Hydronic systems are more complicated to install than electric systems, because the pipes need to be set in the cement under the floor. Obviously, this is expensive to install, but hydronic floor heating has it's advantages over electric heating.

The water holds the heat much better than electric wiring does, and as a result, is more efficient. It also allows for a variety of ways to heat the water itself. You can use gas, propane, oil, electric or even solar heat. Any traditional heating method is a usable option for heating the water that runs through the underfloor tubing.

Electric heat functions like an electric blanket. As electricity flows through the wiring, it encounters resistance, which causes the wires to produce heat. This is much less expensive to install than hydronic heating. It's easy to find floor tiles with the electric wiring built in, ready to just place and install. These are easily available at just about any home improvement store.

Radiant floor heating is especially popular in rooms that are commonly floored with tile, such as kitchens and bathrooms, but it can be used in any room, or the house as a whole, with any type of floor covering, including hardwood and carpet. It's quite nice to walk into the bathroom on a cold day and notice nice, warm tile on your bare feet. This simply isn't available with forced air heat, unless you keep the temperature uncomfortably warm.

Another advantage of radiant floor heating over traditional forced air heat is that there is no air being pushed through the home. This seems almost obvious, but when air is being pushed through the home it can suck the humidity from the air, especially if there a a leak in the system allowing the dryer outside air to mix with the air being heated.

It also can distribute allergens through the air in your home. Of course, there is also the issue of feeling hot air blasting on you while the heat is on. If you're in the wrong part of the room, it's still too cold. In yet another equally wrong part of the room, you're being hit with hot, dry, allergen carrying air. Neither of these options are particularly comfortable.

Overall, radian floor heating may be a little more expensive to install, but in the long run, it will be a more efficient and cost effective way to heat your home. It will also be much more comfortable. That's a double bonus in my book. I would ask, what's the price you would put on your comfort, but the reality is that it's going to be a big savings in the end.

Alex Parry is the author of a heat exchanger cleaning equipment site, where you can also find more information on shell and tube heat exchanger design

Article Source: http://EzineArticles.com/?expert=Alex_Parry

Heat Exchangers for Outdoor Corn Boilers By Sam Streubel

A heat exchanger is a device designed to efficiently transfer the heat from one medium to another. In the case of an outdoor corn boiler, these media would be air and water.

A typical domestic setup would include a water-to-water heat exchanger for hot water and a water-to-air heat exchanger for forced air home heat. Water-to-water heat exchangers are also used to heat hot tubs, swimming pools and the water for radiant baseboard or radiant in floor
heating systems.

Water-to-Water Heat Exchangers

The three most common types of water-to-water heat exchangers used with outdoor
corn boilers are: Sidearm, Shell and Tube, and Brazed Plate. What differentiates these heat exchangers, besides the cost, is the way they're designed to transfer heat from one medium to another and the method used to create turbulence.

A key component in the efficient transfer of heat between liquids is turbulence. The
more turbulent the flow of water through a heat exchanger, the more efficiently heat
is transferred.

Sidearm Heat Exchanger

The sidearm heat exchanger is a popular and inexpensive choice for heating
domestic hot water. It incorporates a pipe within a pipe design where the
water in the inner pipe (your hot water) is heated by hot water from the
boiler circulating through the outside pipe.

Turbulence is created by scrolling on the outer surface of the inside pipe.

This straightforward design prevents clogging by sediment and resists
scaling. One drawback of the sidearm heat exchanger is reported slow
recovery under heavy use. Cost: $130-$150.

Shell and Tube Heat Exchanger

Shell and tube heat exchangers are available in dozens of tube configurations and
sizes ranging from a few feet long to 50 feet or more for power plant steam
generation.

A variation on the shell and tube design is shell and coil where a helical (spiralling) coil
replaces the tubes.

No matter what the design or application, the basic principle is the same. The water to
be heated flows through tubes, and the heated boiler water, encased by the shell,
flows around the tubes.

Turbulence is created by the baffles holding the tubes together in what is called a tube bundle.

Shell and tube heat exchangers for non-chlorinated water
applications, such as domestic hot water and hydronic
heating, are usually constructed with a brass shell and
copper tubes.

For swimming pools and spas the shell should be PVC or stainless steel with stainless
steel tubes. 316L grade stainless steel is commonly used for this application.

Cost: $200-$600 depending on copper or stainless construction and the overall size based on the volume of water to be heated.

Brazed Plate Heat Exchanger

The brazed plate heat exchanger combines compact size with a highly efficient design to produce a device for heat transfer that is up to six times smaller than a shell and tube heat exchanger of similar capacity.

The key to this efficiency lies in their unique construction. Corrugated stainless
steel plates are brazed together (eliminates gaskets) with every
second plate turned 180 degrees. This design creates two highly
turbulent fluid channels that flow in opposite directions (counter flow)
over a massive surface area.

Cost: $100-$500 depending on capacity.

Get better outdoor corn boiler information at Alternative-Heating-Info.com

Article Source: http://EzineArticles.com/?expert=Sam_Streubel

Better Heat Exchanger Cleaning Through Technology By Alex Parry

Maintenance of a platform's Waste Heat Recovery Unit (WHRU) and similar shell and tube heat exchangers can be an extremely dangerous process. It needs to be disconnected, taken off line, and moved to shore for repair. Shell and tube heat exchangers are made of coiled tubes and can become fouled with carbon deposits. The traditional methods for clearing the blockage include bypassing the fouled unit, cutting off bends and cleaning the tubes, then re-welding the U-bends, and complete unit replacement.

The old methods are becoming more outmoded due to advancements in technology. It is inefficient to bypass the unit. Just as it would be less efficient to run your car with 2 cylinders not firing. This inefficiency, of course, also increases operational costs. It is time consuming and costly to cut the U-bends and re-weld them. Sometimes it can be difficult or impossible to get access to reattach them.

Some of these new methods include the ability to clean areas with limited access, and clear deposits from U-bends without ever removing them. This can sometimes be done without even taking the unit offline, and usually takes less time and results in a higher degree of defouling. In fact, many units can be restored to near-factory efficiency. For big refineries, petro-chemical plants, or power plants, this can amount to six figure savings.

The U-bends themselves also retain many deposits, and continue to be a bottleneck to the system. Full replacement carries the cost of completely replacing equipment that, other than the heat exchanger tube fouling, is still in working order. This method also requires the unit be taken offline for the full duration of replacement. obviously this carries a heavy expense and serious loss of production.

Traditional heat exchanger cleaning methods and heat exchanger cleaning equipment have changed very little over the last few decades. Pressure jetting is still the primary means used by many companies, but it is slow, inefficient, and ultimately very costly. Additionally, many companies are skeptical of newer methods, falling back on the "that's the way it's always been done," chain of logic. They are also weary of trying new techniques that are not as "proven" to be effective. Finally, many have long term tube cleaning contracts that do not allow for a change in heat exchanger cleaning technique, unless the contractor were to adopt the new methods.

Newer heat exchanger cleaning equipment and techniques are more technologically advanced, and by extension, require a higher skilled laborer than old style pressure jetting. These new developments include the ability to clean tight radius bends, clean units while keeping them in place, and even while keeping them online. It has also resulted in faster, more efficient cleaning. Many tube bundles can now be cleaned more effectively than with pressure jetting, and jobs that used to take days may now take only a few hours. Difficult to access units are now accessible with these new technologies.

Some of the technology that has been developed includes special nozzles that can be used on tight bends, laser cleaning, and new "smart" metals that respond to changes in density and pressure to prevent damage to the tubes. With these methods, jobs can be finished with less downtime, because cleaning and descaling can be done more quickly. Equipment is also less likely to be damaged in the process. Many of these new processes are safer, create less waste, use no chemicals, and have a significantly reduced environmental impact.

Alex Parry writes about heat exchanger safety at his heat exchanger cleaning equipment site.

Article Source: http://EzineArticles.com/?expert=Alex_Parry

Crack Down on Heat Exchanger Fouling By Mike Watson

Heat exchangers are the unsung heroes of many industrial processes and as such they tend to be taken for granted - nobody likes paying for what is often seen to be unnecessary maintenance. Heat exchangers provide duty for so long, that when they start to drop in efficiency, it's usually a gradual process that goes largely unnoticed - until their performance has deteriorated sufficiently to be a problem. Then it really is a problem - and one requiring urgent attention.

What aggravates the situation is the heat exchanger that has never been cleaned properly, coupled with the commercial need to keep it on-line. When the decision is made to carry out cleaning, often nobody knows what the performance of the exchanger is meant to be, either because the drawings have been lost, or no record of any improvement was made after the original cleaning.

When the exchanger finally is opened up to ascertain the extent of the fouling, it's not surprising to find it is so severe that cleaning takes a lot longer than planned. Any benefit that might have been gained by a quick traditional clean is offset by the extended cleaning duration and costs - and, of course, lost production.

If that sounds like a nightmare scenario, bear in mind that this is the sort of situation specialist cleaning companies encounter every week. Cleaning is often carried out without any firm knowledge of how much of an improvement the cleaning will give and how long its effects will last. Having to make 'finger in the wind' predictions clearly is not a satisfactory way to plan maintenance.

One of the most popular and widely-employed heat exchanger configurations in industry, is the straight or hairpin shell-and-tube exchanger. With hundreds or thousands of small-bore tubes bundled together, the extent of quite modest scaling can involve major work to return the exchanger to anything near its commissioned performance. If the outside of the bundle is heavily scaled as well, the cleaning challenge rises by an order of magnitude.

There is potential to bring about a significant improvement in heat exchanger accessibility and 'cleanability', by working more closely with the people who design heat exchangers and fabricate industrial plants.

Better design would lead to improved cleaning - where improved means faster, cleaner and safer, possibly in-situ or even on-line and with better waste containment. It would then be easier and quicker to clean exchangers back to bare metal to return them to duty and their design performance faster.

Plants are generally specified and ordered on the basis of throughput, not accessibility and ease-of-cleaning. Suppliers are happy to comply with this and therefore tend to design heat exchangers with 30-40% excess capacity to ensure that they can continue to provide duty, even when quite extensively fouled. Heat exchangers the world over are currently designed and installed with a view to using one of three systems for cleaning: chemical, pressure jetting and/or mechanical and this approach has remained unchanged for over 50 years.

When it comes to maintenance, refineries - like most of industry - tend to compete on the same basis - a 21-day shutdown is decreed because it's been done that way for maybe the last 20 years. The same cleaning methods are generally used slavishly, with high-pressure water as the cleaning medium.

Most companies look at their heat exchangers in isolation and simply try to extend their run-time, instead of having them designed or re-designed so they can be cleaned more regularly, but faster and better. BP's Coryton refinery, for instance, managed to reduce cleaning time on one shell-and-tube heat exchanger from three days to three hours by applying a different approach to cleaning it.

If a plant is optimized for cleaning, almost full production can be maintained throughout the cleaning process. Relatively minor mechanical changes, such as adding isolating valves to heat exchangers, means that each exchanger, or bank of exchangers, can be taken down and cleaned while the others remain on-line. A redesign of the exchanger so that a header can be removed, means it can then be cleaned with a different system to the standard high-pressure water jetting, in a few hours instead of several days.

At Dow Corning's silicone plant in Barry, south Wales, a tubular boiler and fire tube in the Energy Recovery Unit (ERU) required the removal of a 5mm layer of deposit in as short a time as possible to minimize lost production. Another obstacle was that the unit, which carries waste gases, takes 48 hours to cool and prepare - even with the introduction of a chilled nitrogen purge - before personnel can enter to clean it manually.

The solution involved developing a bespoke remote de-scaler, which was inserted through a small 50cm man-way. Once inside, the de-scaler expanded to fit the hot fire tube, while reaching the full length of the carbon steel tube. With cooling time and man entry eliminated, the shutdown was reduced from five days to three and there was a noticeable improvement in performance of the ERU when it came back on line.

Improved cleaning cycles also mean the rate of future fouling build-up is reduced, which in turn reduces the risk of tubes corroding as a result of the exchanger being open to the atmosphere longer for cleaning.

Heat exchange surfaces therefore remain smoother and provide better heat transfer. If and when the exchanger does foul up, it's easier to clean next time around, using whichever system is preferred. This would represent a change of practice to what has been the norm since the 1980s, for instance, when what was then Mobil in the UK was one of the first refineries to decide that it would extend run-times by abandoning the annual clean and only clean every two years.

Today, typical service intervals have become stretched to three and even four years in some cases, but the apparent operational savings are actually a false economy. Shareholders are indeed happy, because they are getting longer run times, while competing refineries have little choice but to play the same game or lose millions during more frequent shutdowns. Four years down the line, however, the plant will have to come down for major cleaning and maintenance and it will experience a far higher capital replacement cost than ever before.

Mike Watson, Managing and Technical Director

Run by its founder and inventive visionary Mike Watson the company is supported by a wealth of hand selected department managers. With many years experience in developing engineered solutions to complex problems in industry, Mike’s belief is that convention should always be challenged in order to find a better way to achieve improved results. This “never say never” approach, led to him founding Tube Tech in the 1980s. Today, the company cleans the toughest cleaning projects the world can throw at it. Mike often says “If people say it can’t be done, its like a red rag to a bull to me. I will always find a solution”. Mike continues to invest in new technology development, leading the world in new cleaning methodology.

Article Source: http://EzineArticles.com/?expert=Mike_Watson

New Cure For Fouled Plant Saves Money, Improves Performance By Mike Watson

Cleaning a blocked WHRU conventionally involves costly cutting off of the serpentine bends and re-welding after cleaning; this is no longer necessary. When a platform's heavy plant fails, it means highly involved and often hazardous operations to disconnect it, move it off line, and then transfer it to a supply ship to be taken ashore for repair.

Plant-like Waste Heat Recovery Units (WHRUs) and shell-and-tube heat exchangers are comprised of coiled tubes that can become restricted with carbon deposits. Standard industry approaches to solving the blockage problem are:

* Bypass the fouled unit

* Cut off the U-bends, clean the straight tubes and then weld the U-bends back in place

* Replace the complete unit

None of these options are completely satisfactory. Bypassing the unit causes inefficient burning of fuel and higher platform operating costs. Cutting the U-bends is time-consuming, with no guarantee there will be access to reattach the bends. When the exchanger is returned to duty, it under-performs because deposits remain in the U- bends, so the exchanger shortly has to be cleaned again. Replacing the complete unit is the most expensive option due to the cost of the replacement unit and platform production loss from lengthy downtime.

A WHRU on a North Sea platform became restricted and had to be shutdown. The unit already had been disconnected and transported ashore when the operator decided to have Tube Tech try to clean it before ordering a $500,000 replacement. It can take up to a year for a new replacement unit to be installed because of a six-month manufacturing lead-time plus WHRUs can only be taken off line once a year when the platform's gas turbines are down for maintenance.

Tube Tech established a three-stage plan. Phase one was locating the position and length of blockages within the unit; phase two was a systematic unblocking; and, phase three was a thorough cleaning. This did not involve removing any U-bends. Because of the size of the WHRU, two 14.5-metric ton (14.9-ton) cranes were used to change the position of the unit during cleaning. The WHRU was de-scaled, unblocked in two weeks, and restored to peak efficiency.

The operator saved £150,000 ($297,350) in possible manufacturing costs and subsequent rig production losses through on-site cleaning. After considering cost implications of a failure in one of two other WHRUs they owned, the operator contracted Tech Tube to clean both units on-site as a precaution.

A serpentine shell-and-tube exchanger on a Persian Gulf platform developed a similar fouling problem. Tube Tech decided on a seawater-fed jetting system they had devised. It features low-flow, high-pressure water delivered through unblocking and de-scaling nozzles, supplemented with a specially-developed U-bend nozzle which can negotiate close-radius bends. Even in the limited confines of the platform, a comprehensive clean was completed on time and on-budget.

Mike Watson, Managing and Technical Director

Run by its founder and inventive visionary Mike Watson the company is supported by a wealth of hand selected department managers. With many years experience in developing engineered solutions to complex problems in industry, Mike’s belief is that convention should always be challenged in order to find a better way to achieve improved results. This “never say never” approach, led to him founding Tube Tech in the 1980s. Today, the company cleans the toughest cleaning projects the world can throw at it. Mike often says “If people say it can’t be done, its like a red rag to a bull to me. I will always find a solution”. Mike continues to invest in new technology development, leading the world in new cleaning methodology.

Article Source: http://EzineArticles.com/?expert=Mike_Watson