Delafield and Steam
Since the 18th century steam has been applied to a variety of practical uses. At first it was applied to reciprocating pumps, but from the 1780’s rotation engines began to appear driving machinery and at the turn of the 19th century steam powered land and sea transport make it appearance.
However the presence of several phases between heat source and power delivery meant that is has always been difficult to obtain a power to weight ratio anywhere near that obtainable from internal combustion engines or electrical motors, which has given the steam has an out of date image, therefore there was no commercial incentive to invest in steam research and development. However it is important to note that power supplied to the electricity grid is predominantly generated using steam, so indirectly the world’s industry is still dependent on steam power.
When we take a good look at various industries we see the steam is still being used in a wide range of industries.
Delafield’s Research and Development team recognised that in this modern age steam is still used as an energy source in many commercial and industrial processes and is usually produced with centuries old steam boiler technology.
The company set out on a mission is to make the best use of our present and future energy sources and ensure that fuels and other primary energy sources get efficiently converted into services processes we need.
Our source of inspiration is the environment and the planet we live on, we treat earth, the environment, people and nature respectfully in everything we do. In this way Delafield is the leader in the field of energy innovation. We are continually searching for opportunities and solutions to make our energy usage more efficient and environmentally sustainable.
During the last 14 years of intensive research and prototype development Delafield invented and develop a reliable and efficient heat exchange technology, HRC Harmonic Resonance Combustion, an energy technology far superior in efficiency and emissions to any steam or heat exchange technology on the market to date.
A technology that will revolutionise the boiler and heat exchange market.
HRC and Steam
Harmonic Resonance Combustion Technology (HRC)
Do you know that 40% of all energy consumed in industry is for the production and delivery of steam or hot water, produced by conventional steam and hot water boilers with a legacy that dates back 200 years and corresponding levels of low efficiency which rarely exceed 66% conversion from energy to steam delivery. The HRC system harnesses technology and reduces fuel costs by 30%. The market is significant and particularly evident where intermittent (rather than continuous flow) steam is required. This market is primarily represented in the food processing industry but also includes paper and pulp, space heating, grain drying, spay drying, dairy products, fruit juices, hospitals and pharmaceutical production
Imagine a technology that provides instant steam that can be shut off just as quickly; the HRC system meets that requirement while it also improves productivity, is extremely energy efficient and cost effective The HRC system reduces fuel consumption by 30%, through increased combustion efficiencies which results in higher profit margins and associated cost savings.
This HRC system provides the solution to the rising cost of fuel; it offers steam instantly with reduced need for blow-down.
The HRC system represents the next generation in heat exchange technology offering superior capabilities, more efficient combustion, better energy performance, lower environmental impact, and greater flexibility with a lower cost profile.
The “if it ain’t broke don’t fix it” attitude is finally being questioned in this very conservative industry as energy cost and consumption become a central focus of industrial development. There is now a strong appetite for this type of disruptive technology. We are confident that the HRC system will gain rapid market acceptance as its capabilities become known in target markets.
How we create high quality steam at low cost ?
A Delafield HRC Steam System is a, once through, steam generator utilizing an array of helical coils to exchange the heat of the pulsating and oscillating combustion gases to the, forced flow, incoming feedwater and create high quality steam in this process.
The feedwater pump is a multi stage pump unit that is supplied with each Steam System. This pump continuously supplies feedwater to the helical coil heat exchangers, where heat is transferred from the products of the pulsating combustion process to the feedwater. The flow of feedwater is counter to the flow of the pulsating and oscillating combustions gases, these facts contributes to the high fuel-to-steam efficiency of Delafield Steam systems.
In order to ensure that the end user get the highest quality steam for their processes, the Delafield’s steam systems includes a steam separator that separate any remaining water droplets from the steam vapour and provides significantly higher quality steam than traditional boilers. Our dry steam quality is 99.5% or better in most instances. Higher quality steam means higher energy. Every kilogram of steam typically contains 3 to 5 times the amount of heat in a kilogram of water at the same temperature and that heat is more easily recovered in your process than the heat in water. In addition to reducing the amount of water going to your process, high quality steam also provides the advantage of reducing the solids carried into your system. Carry over water or solids that can foul your equipment or in the case of steam injection will cause product quality problems.
Delafield Steam System provide very fast start-up, typically, full steam pressure with full output in 1 to 2 minutes, depending upon the size of the unit. This is the result of the small water content and the pulsating and oscillating combustion process. Most conventional boilers of the same size require 1 or 2 hours start-up time. This fast start-up ability results in reduced fuel and operating costs. Many operators of conventional boilers keep a boiler in a warm state during periods of non-use just so that it will be available quickly when needed.
Since this is not necessary with a Delafield Steam System, the fuel would otherwise be used during that stand-by time is saved. Fast start-up means more fuel and energy saved but can also result in reduced labour cost since it may not be necessary to bring an employee into the plant, earlier than otherwise needed, just to start-up the boiler,
Delafield steam systems do not require a full time boiler attendant and classified as a fully un-attended steam systems with a non hazard level E.
Many processes have strict requirements for steam temperature and pressure in order to ensure good quality products. These same processes may have widely varying steaming rates. These two demands are difficult to meet with one single, larger, conventional steam boiler, since a relatively long time is needed to increase steaming rates significantly, even when conventional boiler are designed with turndown ratio controllers, which typically is a ratio of 4:1 between full boiler output and the boiler output operating at low fire. The ability of a conventional boiler to turndown reduces frequent on and off cycling. Fully modulating boilers are typically designed to operate down to 25% of rated capacity. At a load that is 20% of the load capacity, the conventional boiler will turn off and cycle frequently, A boiler operating at these low load conditions can cycle as frequently as 12 times per hour or 288 times per day, every time the boiler cycles off, it must go through a specific start-up sequence for safety assurance and with each cycle, pre and post purge airflow removes heat from the boiler and sends it out the stack and requires some time to place the boiler back on line. If there is a sudden load demand the start up sequence cannot be accelerated. Keeping the boiler on line assures the quickest response to load changes but increases the energy and fuel consumption dramatically. In addition to this and Frequent cycling also accelerates wear of boiler components and maintenance increases but more importantly, the chance of component failure increases.
Delafield Steam Systems are made for just such applications. The low water content, coupled with the installation of multiple smaller units in series is part of the basic design strategy, this allows for rapid response to various steam demands without a drop in steam pressure and temperature. In addition, the units are equipped with PLC Control and can include control logic specifically designed to account for these types of processes and varying load demands.
Size does matter
Steam boiler capacity and requirement are generally determined by many different type of load variations in the system. Boiler over sizing occurs too often when future expansion and safety factors are added to assure that the boiler is large enough for the application. If the boiler is oversized the ability of the boiler to handle minimum loads without cycling is greatly reduced and capital investment is wasted, also boiler room space is at a premium in most installations, either for an existing installation, where the boiler room may already be crowded, or for a new building, where the cost of construction is important.
Delafield is the once again the ideal solution to these size and space considerations. Our small footprint and light weight means that the Delafield Steam System fits through a standard doorway and can be wheeled in and out of an existing plant rooms or placed without the use of heavy lifting equipment and without the need to alter or remove walls or new constructions.
One or two, or as many as required, of our small steam generators in series, for the larger steam capacity, the multiple unit arrangement will easily fit in the space required for one large conventional steam boiler. With a multiple installation of these smaller, quick response, steam generator arrangements it is possible switch on or off as required and so adjust for high and low steam demand, variable and swing loads and thereby reducing the total fuel/energy consumption.
Industry today is faced with tighter regulations with regards to emissions. The regulatory requirement to clean-up the environment has placed an ever increasing burden on all of us to look for better and cleaner and more efficient ways to utilize our natural resources. Our commitment to the environment with innovations and quality, Delafield has been able to develop a environmentally friendly pulse combustion system that emit very low levels of greenhouse gas emissions, a new generation combustion systems that meet the most stringent air pollution or emission requirements and standards.
Our Ultra Low NOx-Low CO burner was developed by Delafield Research. This advanced HRC combustion burner technology provides ultra-low emissions, combined with the highest fuel to steam efficiencies, the Delafield Steam Systems are considered the new generation in combustion technology and steam generation.
Dissolved solids are introduced into most steam system and, likewise, the level of the Total Dissolved Solids (TDS) must be controlled in every boiler and steam generator. This is accomplished by blowing down quantities of the highly concentrated boiler water in order to remove some of the TDS. Although necessary, blowdown is inefficient since the water that is removed during blowdown is water that has been heated to the temperature of the steam. Thus blowing down removes heat that has just been added from the fuel burned. Reducing blowdown, therefore, reduces fuel costs. The blowdown rates in Delafield Steam Systems is typical Zero, but a small fraction of a conventional boiler blow down may be required with extreme poor feed water quality.
All of Delafield’s Steam Systems can be equipped with PLC control systems. There are a variety of configurations available that allow tailoring the system to your specific needs. The advantages of PLC control systems include:
o Simplified control panel resulting in less maintenance than with relay logic systems.
o Improved response to widely varying steam demands, while maintaining close tolerance on steam pressure.
o Easier interconnection with plant monitoring and control systems.
o Easy access to operating and control information.
o Easy selection of control settings.
Safety is the most important priority when it comes to the generation, distribution and use of steam; therefore, selecting the safest steam generating system is just common sense. With the Delafield Steam system there can never be a steam explosion, a particular significance is the fact that this steam generators does not use a large pressure vessels filled with water. This in fact contributes to the many of the advantages that Delafield steam system provides.
Steam explosions that cause death, injury and serious property damage, result from the near instantaneous, uncontrolled, release of energy that is present in steam at saturated conditions and pressure that exist in steam boilers. ( note: When steam under pressure is released instantly to atmospheric pressure the volume increases 1600 time) These explosions cannot occur with the Delafield Steam System because there is relatively little water in the steam generator and that water is contained in the array of stainless steel helical coils heat exchangers. Even if, in an unlikely event that there is a leak in one of the many stainless steel helical coils, all of the energy in the saturated water cannot be released instantaneously, because the water must travel through the coil to reach the point of the leak, in this case scenario, flame will be extinguished by the release of the water from this single coil and the system automatically shuts down.
Introduction in the economics of the Delafield HRC Steam System Technology
Efficiency and cost savings
The efficiency of a boiler should be an important part of a purchase evaluation since the annual cost of fuel can easily be 3 to 4 times the installed cost of the equipment. Therefore, a difference in efficiency and the resultant difference in fuel cost can easily offset a difference in installed cost. In many cases, the fuel, water treatment and maintenance savings in the first year alone can exceed a difference in installed cost and, of course, these savings are on-going year after year, after year.
While it is important to consider efficiency in an equipment purchase, it is equally important to understand efficiency to the point that the purchaser can be assured that values are being compared on an equal basis. The subject of efficiency for a steam boiler is rather complex when all of the elements that affect efficiency are considered and a complete thermodynamic analysis is performed. Fortunately, it is not necessary to understand the process in detail, but a basic understanding of the facts and terms can help ensure a good efficiency evaluations. These facts are discussed in the context of the discussion on efficiency terms.
There are several terms used to qualify efficiency when used in the context of a steam boiler. These includes simply efficiency, boiler efficiency, thermal efficiency, combustion efficiency, fuel-to-steam efficiency and operating efficiency.
The terms, Efficiency and Boiler Efficiency, by themselves are, essentially, meaningless since they must be qualified in order to understand their significance.
In general, the term, Thermal Efficiency refers to the efficiency of a thermal process. This is as opposed to Mechanical Efficiency, the efficiency of a mechanical process. When used in conjunction with boilers, Thermal Efficiency sometimes refers to the efficiency of the heat exchanger. In any event, this term is not significant for purposes of comparing one boiler, or steam system, to another. While the thermal efficiency of the heat exchanger is an important factor, its importance lies in its contribution to the Fuel-to-Steam Efficiency.
While the terms Efficiency and Thermal Efficiency are not meaningful for comparing one steam boiler to another, the terms Combustion Efficiency and Fuel-to-Steam Efficiency are very meaningful. Of these, Fuel-to-Steam efficiency is the most important because it is a measure of the energy that is converted to steam and that is after all the reason a user installs a steam boiler or steam generator to produce steam. Fuel-to-Steam efficiency is equal to combustion efficiency less the percent of heat losses through flue gas, radiation and convection. A recent boiler efficiency in the USA study shows that conventional steam boilers run on average 67% efficient. The Delafield Steam System runs at a fuel to steam efficiency of >94%, in addition to this the steam system has very low flue gas exhaust temperature and no heat is lost through the steam generator external surface. Delafield Steam Systems are also known for their clean burning characteristics, near zero NOx emissions, this efficiency and clean burning characteristics comes from two primary areas, design and operational.
The basic design characteristics that lead to high fuel-to-steam heat transfer include
- The Pulsating and oscillating combustion cycles that drives a resonant pressure wave, which in turn enhances the rate of combustion and increase heat transfer.
- Low exhaust temperature and reduced greenhouse gas emissions. This will add to the heat exchange energy available to the helical coil heat exchangers.
- Counter flow of the feedwater to the combustion gases. That leads to optimum heat transfer.
- Heat exchanger coils designed and spaced to ensure turbulent oscillating flow of the combustion product gases across the coils, thus facilitating exceptional high heat transfer rates.
- Controlled circulation as opposed to natural circulation used in conventional boilers.
- Exterior surface temperatures are close to ambient temperature, therefore negligible convection and radiant heat loss. Radiation and convection losses from conventional boilers to the boiler room will normally run 1% to 2%. These losses will not occur on a Delafield Steam Generator.
- Pulsating and oscillating combustion with controlled circulation and counter flow heat exchanger design account for a substantial improvement in combustion efficiency and in fuel to steam efficiency over conventional boilers. The stack temperature is one of the measures of efficiency, a Delafield steam Generator will typically be 60-80 ⁰C below the temperature of the steam being produced. Whereas a typical conventional boiler will have a stack temperature 60-80 ⁰C above the temperature of the steam produced.
Operational factors, that lead to fuel savings include:
- Extremely fast start-up, full steam output in less than 1 or 2 minutes, this eliminate the need to start a conventional boiler 1 to 2 two hours before it is needed or to keep a boiler in a warm state during periods of non-use, such as during the evening, night or on weekends.
- Eliminated blowdown. Blowdown in a Delafield Steam Generator, depending on feedwater quality, is typical nonexistent, this amount to a major savings in fuel cost when compared to the typical blowdown in a conventional boiler, that ranges from 4 – 8 percent of the feed water flow rate, but can be as high as 20 percent in extreme poor quality feed water. Blowdown water contains heat energy so the less the blowdown the less the loss of heat and energy resulting in cost savings and lower fuel consumption.
Each of the terms, Design and Operational, discussed above, refer to the efficiency of a boiler when operating at a fixed condition. For instance, at 100% load with specified air and feedwater temperatures, etc. These efficiencies are unquestionably important, but there are other operational factors that affect the total annual fuel bill and operating cost and this can have an effect that may be greater than the difference of a point or two in the efficiency.
The Delafield steam generator can deliver a fuel to steam efficiency in excess of >94
TOTAL COST SAVINGS POTENTIAL
Since fuel is not the only cost in the steam generating process, the many factors of the savings will depend upon the specifics of the application, calculating the total steam production process cost and the total cost savings that can be achieved by the installation of one or multiples of the Delafield steam generating system must include the following considerations;
o Capital cost of the equipment
o Fuel to steam efficiency
o Reduced blow-down
o Effluent charge
o Boiler chemicals
o Boiler attendant
o Start-up loss
o Standby loss
o Boiler room cost
o Maintenance and service
o Steam quality/product contamination
o Safety and regulatory considerations
o Low emissions
If we consider these factors above, the achievable total cost savings in the production process of steam are in the range of 40% to 50% or greater.
With the ever increasing cost of fuel/energy and labour the Delafield steam generating system is the “new generation steam generator” that will generate the highest quality steam and additional revenue to your company’s bottom line.