rotary kiln incinerator - design and manufacture

rotary kiln incinerator - design and manufacture

The rotary kiln incinerator is manufactured with a rotating combustion chamber that keeps waste moving, thereby allowing it to vaporize for easier burning. Types of waste treated in a rotary kiln incinerator

The picture"photo 1"gives a schematic overvieuw of the systemmanufactured totreat the waste in a rotating drum, we use a counter current rotary kiln. There are 2 different types of rotary kiln, co-current rotary kilns and counter current rotary kilns. Read here more about the different types of rotary kiln.

Energy recovery is always an individual design, and very attractive is electricity. But electricity is also the most complicated and less economical profitable for small installations ( the min. capacity is 3 ton/h of waste). If heat can be used in another process on site, for example in a dryer. It has to be taken into consideration that a connection between incinerator and the production process (dryer) can be the most efficient solution. The disadvantage can be if there is a production stop of the incinerator, the process (dryer) can not always stop at the same time.

For example : We produce steam as energy recovery, also for electricity production. The post combustion is strictly vertical and the boiler also has a vertical design for evacuation of dust. Our design is made for continuous operation of a steam boiler. The next drawing gives a possible set up of the installation. This is our set-up, created by people with operation experience with incinerators, and it results in this lay-out.

Depending on the amount of Chlorine, S, N or other chemicals in the waste stream there is a wet or/and dry scrubbing system available for the flue gas treatment. Flue gas treatment systems are standard systems, and normal chemical reaction. So, for correct flue gas treatment we need to take care for:

rotary kiln incinerator-dongding incinerator manufacturer

rotary kiln incinerator-dongding incinerator manufacturer

Rotary kiln incinerator incineration treatment is one of the garbage solutions, which can solve the harmfulness of waste and realize the reduction of hazardous waste. So everyone knows the incineration...

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The solution is highly valued in todays social development, and at this stage, it has already had relevant solutions to prevent and cure. That is to carry out special incineration treatment. To apply a...

rotary kiln incinerator for sludge incineration

rotary kiln incinerator for sludge incineration

Sludge is a common solid waste in daily life, which is commonly found in sewer pipe networks and sewage treatment plants. The amount of sludge waste produced in the industry is huge each year, among which electroplating sludge, leather sludge, pickling sludge, oily sludge, sewage sludge, and other types of sludge discharge are increasing day by day.

The sludge waste contains a lot of harmful substances, including heavy metals, bacteria, pathogens, etc. If it is not treated, it will inevitably have a greater impact on the environment and human health. Sludge treatment came into being under such circumstances. Sludge treatment is the reduction, stabilization, and harmless processing of various types of sludge such as concentration, conditioning, dehydration, stabilization, drying, or incineration.

There are roughly four methods for sludge treatment in the world, namely reclamation, landfill, incineration, and land use. Most landfills are open-air sites. After the rain, a large amount of sludge containing oil that is difficult to degrade organic matter, heavy metals, and pathogenic microorganisms will corrode and penetrate the land, posing safety hazards to the soil, and causing new pollution to the surrounding environment of the city. In Europe, the treatment of sludge through sludge incineration has become a very important way. Due to stricter restrictions on sludge accumulation, incineration of sludge may become the only way to treat sludge.

The sludge incineration process needs to be carried out in a sludge rotary kiln. Sludge waste rotary kiln is a kind of hazardous waste rotary kiln incinerator, which is specially used to treat sludge waste. It is a rotary kiln calcining equipment integrating drying, heating, and calcination. During the sludge incineration process, all germs and pathogens are completely killed by the high temperature in the sludge rotary kiln, and the toxic and harmful organic residues are decomposed by thermal oxidation. The sludge is incinerated through the sludge rotary kiln to achieve the greatest reduction in volume, and the final product incineration ash is obtained. Incineration ash can be used as a raw material for cement production to fix heavy metals in the concrete to prevent them from re-entering the environment.

The internal temperature in the sludge rotary kiln incinerator is generally between 1350-1650, or even higher. The materials in the kiln are in a highly turbulent fluidization state during the incineration of sludge. Therefore, the harmful organic matter in the sludge in the kiln can be fully burned, and the incineration rate can reach 99.999%. Even stable organic matter such as dioxins can be completely decomposed.

Since the feeding point of the dried sludge is in a decomposition furnace higher than 850C, the furnace has a large heat capacity and a stable temperature, which effectively inhibits the formation of dioxin precursors. The practice of disposing of toxic and hazardous wastes in cement kilns at home and abroad shows that the concentration of dioxin emissions produced by waste incineration is far below the emission limit.

The waste gas and dust discharged from calcination are collected by the bag filter at the end of the kiln as cement raw materials and then enter the kiln for calcination. No hazardous waste fly ash is generated.

The refractory bricks, raw materials, kiln skin, and clinker in the sludge waste rotary kiln are all alkaline, which can absorb SO2, thereby inhibiting its emission. In the process of cement firing, the heavy metals in the sludge and slag can be fixed in the structure of the cement clinker. So as to achieve the role of being cured.

Through the treatment of the rotary kiln incinerator, the organic and inorganic components in the sludge can be fully utilized, and the resource utilization efficiency is high. The sludge contains some organic matter (above 55%) and combustible components, which will generate heat when calcined in the rotary kiln. The low calorific value of sludge is about 11MJ/kg, which is equivalent to lean coal in the sense of calorific value. Lean coal contains 55% ash and 10%-15% volatile matter and has a calorific value of 10-12.5MJ/kg.

The sludge rotary kiln incinerator has higher treatment efficiency, the incineration products can be used as cement raw materials, and the heat produced by incineration can be used for power generation, with significant economic benefits. It has become the first choice of incineration equipment for many sewage treatment plants and industrial solid waste treatment enterprises. As a high-quality rotary kiln supplier, AGICO welcomes you to send inquiries for details at any time.

rotary kiln - an overview | sciencedirect topics

rotary kiln - an overview | sciencedirect topics

Rotary kilns are synonymous with cement making, being the workhorses of this industry. There are many types of rotary kiln arrangements for producing cement clinker with each incremental design goal aimed at improving energy efficiency, ease of operation, and product quality and minimizing environmental pollutants. Rotary cement kilns can be classified into wet-process kilns, semidry kilns, dry kilns, preheater kilns, and precalciner kilns. All of these are described in the book by Peray (1986) and many others, hence we will not dwell upon them here. Rather, we will briefly show the pertinent process chemistry and the heat requirements that drive them, so as to be consistent with the transport phenomena theme.

Rotary kilns have been used in various industrial applications (e.g., oil shale retorting, tar sands coking, incineration, cement production, etc.). The rotation of a cylinder-shaped vessel positioned longitudinally approximately 30 of the horizontal position ensures a continuous motion of catalyst between the entrance and exit of the kiln. With regard to the spent catalyst regeneration, the description of rotary kilns was given by Ellingham and Garrett [451]. There are two types of rotary kilns, i.e., direct fire and indirect fire.

The direct fire is a single shell vessel with rings added inside to slow the catalyst as it tumbles from the inlet (elevated part) towards outlet (lower part). The oxidation medium flows countercurrent to catalyst movement. The O2 concentration in the medium will decrease in the same direction because of its consumption. Therefore, the zone in the vessel located near the inlet may function as a stripper of volatile components of coke. The kiln is fired by gas burners directly against the outer shell of the vessel. The temperature inside the kiln is controlled by adjusting the burner heat, varying concentration of O2 in the oxidizing medium and its flow. The indirect fire kiln comprises a double-shell cylinder vessel. The inner shell is similar as that of the direct fire kiln. The space between the shells is heated either by combustion gas or steam. In some cases, the inner cylinder shell is ebullated allowing hot gases or steam to enter and contact the tumbled catalyst. The catalyst temperatures are controlled by monitoring the temperatures of the inlet and outlet gases. It is believed that Eurocat process evolved from a rotary kiln process by be improving the control of operating parameters such as temperature, gas flow, speed of rotation, etc.

The rotary kiln is used to process the lead-containing components resulting from the breaking and separation of waste batteries. The main components of a rotary kiln are an inclined cylindrical, refractory-lined reaction shaft equipped to rotate over rollers and a burner. Process heat is generated by burning fine coke or coal contained in the charge and by the exothermic heat of the PbO reduction by CO. This process produces molten lead and a slag with 35% Pb. A drawback of this technology is the short life of refractory liners.

The rotary kiln is a long tube that is positioned at an angle near horizontal and is rotated. The angle and the rotation allow solid reactants to work their way down the tube. Speed and angle dictate the retention time in the kiln. Gas is passed through the tube countercurrent to the solid reactant. The kiln is operated at high temperatures with three or four heating zones depending on whether a wet or dry feed is used. These zones are drying, heating, reaction, and soaking. Bed depth is controlled at any location in the tube with the use of a ring dam.

The most common reactor of this type is the lime kiln. This is a noncatalytic reaction where gas reacts with calcium carbonate moving down the kiln. Other reactions performed in the rotary kiln include calcination, oxidation, and chloridization.

Use of rotary kilns for hazardous waste incineration is becoming more common for disposal of chlorinated hydrocarbons such as polychlorinated biphenyls (PCBs). Flow in these kilns is cocurrent. Major advantages include high temperature, long residence time, and flexibility to process gas, liquid, solid, or drummed wastes.

The rotary kilns used in the first half of the twentieth century were wet process kilns which were fed with raw mix in the form of a slurry. Moisture contents were typically 40% by mass and although the wet process enabled the raw mix to be homogenized easily, it carried a very heavy fuel penalty as the water present had to be driven off in the kiln.

In the second half of the twentieth century significant advances were made which have culminated in the development of the precalciner dry process kiln. In this type of kiln, the energy-consuming stage of decarbonating the limestone present in the raw mix is completed before the feed enters the rotary kiln. The precalcination of the feed brings many advantages, the most important of which is high kiln output from a relatively short and small-diameter rotary kiln. Almost all new kilns installed since 1980 have been of this type. Figure1.4 illustrates the main features of a precalciner kiln.

The raw materials are ground to a fineness, which will enable satisfactory combination to be achieved under normal operating conditions. The required fineness depends on the nature of the raw materials but is typically in the range 1030% retained on a 90 micron sieve. The homogenized raw meal is introduced into the top of the preheater tower and passes downwards through a series of cyclones to the precalciner vessel. The raw meal is suspended in the gas stream and heat exchange is rapid. In the precalciner vessel the meal is flash heated to ~900C and although the material residence time in the vessel is only a few seconds, approximately 90% of the limestone in the meal is decarbonated before entering the rotary kiln. In the rotary kiln the feed is heated to ~ 1500C and as a result of the tumbling action and the partial melting it is converted into the granular material known as clinker. Material residence time in the rotary kiln of a precalciner process is typically 30 minutes. The clinker exits the rotary kiln at ~ 1200C and is cooled to ~60C in the cooler before going to storage and then being ground with gypsum (calcium sulfate) to produce cement. The air which cools the clinker is used as preheated combustion air thus improving the thermal efficiency of the process. As will be discussed in section1.5, the calcium sulfate is added to control the initial hydration reactions of the cement and prevent rapid, or flash, setting.

If coal is the sole fuel in use then a modem kiln will consume approximately 12 tonnes of coal for every 100 tonnes of clinker produced. Approximately 60% of the fuel input will be burned in the precalciner vessel. The high fuel loading in the static precalciner vessel reduces the size of rotary kiln required for a given output and also reduces the consumption of refractories. A wider range of fuel types (for example, tyre chips) can be burnt in the precalciner vessel than is possible in the rotary kiln.

Although kilns with daily clinker outputs of ~9000tonnes are in production in Asia most modem precalciner kilns in operation in Europe have a production capability of between 3000 and 5000 tonnes per day.

A rotary kiln is a physically large process unit used in cement production where limestone is decomposed into calcium oxide which forms the basis of cement clinker particles under high temperatures. The modelling of rotary kilns are well documented in literature. Mujumdar et al. 2007 developed an iteration based rotary kiln simulator (RoCKS), which integrates models for a pre-heater, calciner, kiln and clinker cooling that agreed well with observations in industry. The model takes complexities in reactions and heat transfers with different sections into account by coupling multiple models with common boundaries regarding heat and mass communications. Other work (Ngadi and Lahlaouti, 2017) neatly demonstrates an experimentally proven kiln model being applied for screening of combustion fuel used for kilns, and how it may impact the production. This contribution coupled modelling of reactions and heat transfer in the bed region and another model for combustion and heat transfer in the freeboard region.

While modelling of these processes with varying degree of complexity has been performed, proper uncertainty and sensitivity analysis of these models have not been given due importance/consideration. As the use of computer aided process engineering tools increases, the need for robust uncertainty and sensitivity analysis frameworks becomes more important. There are several frameworks of uncertainty and sensitivity analysis applied for different problems, from good modelling practice (Sin et al., 2009) to process design and product design (Frutiger et al. 2016). These frameworks typically include the following steps (0) problem statement, (i) identification of input sources of uncertainties, (ii) sampling (iii) Monte Carlo simulations and (vi) sensitivity analysis. The purpose of this work is to perform a systematic uncertainty and sensitivity analysis of rotary kiln process design in order to address the following: (1) Given a certain base case design, what is the impact of uncertainties in the model and measurements on the key process design metrics (minimum required reactor length and degree of conversion), and, (2) given a certain source of uncertainties, what is the robust design to ensure process performance with 95 % confidence.

The rotary kiln is often used in solid/liquid waste incineration because of its versatility in processing solid, liquid, and containerized wastes. The kiln is refractory lined. The shell is mounted at a 5 degree incline from the horizontal plane to facilitate mixing the waste materials. A conveyor system or a ram usually feeds solid wastes and drummed wastes. Liquid hazardous wastes are injected through a nozzle(s). Non-combustible metal and other residues are discharged as ash at the end of the kiln. Rotary kilns are also frequently used to burn hazardous wastes.

Rotary kiln incinerators are cylindrical, refractory-lined steel shells supported by two or more steel trundles that ride on rollers, allowing the kiln to rotate on its horizontal axis. The refractory lining is resistant to corrosion from the acid gases generated during the incineration process. Rotary kiln incinerators usually have a length-to-diameter (L/D) ratio between 2 and 8. Rotational speeds range between 0.5 and 2.5 cm/s, depending on the kiln periphery. High L/D ratios and slower rotational speeds are used for wastes requiring longer residence times. The kilns range from 2 to 5 meters in diameter and 8 to 40 meters in length. Rotation rate of the kiln and residence time for solids are inversely related; as the rotation rate increases, residence time for solids decreases. Residence time for the waste feeds varied from 30 to 80 minutes, and the kiln rotation rate ranges from 30 to 120 revolutions per hour. Another factor that has an effect on residence time is the orientation of the kiln. Kilns are oriented on a slight incline, a position referred to as the rake. The rake typically is inclined 5 from the horizontal.

Hazardous or non-hazardous wastes are fed directly into the rotary kiln, either continuously or semi-continuously through arm feeders, auger screw feeders, or belt feeders to feed solid wastes. Hazardous liquid wastes can also be injected by a waste lance or mixed with solid wastes. Rotary kiln systems typically include secondary combustion chambers of afterburners to ensure complete destruction of the hazardous waste. Operating kiln temperatures range from 800C to 1,300C in the secondary combustion chamber or afterburner depending on the type of wastes. Liquid wastes are often injected into the kiln combustion chamber.

The advantages of the rotary kiln include the ability to handle a variety of wastes, high operating temperature, and continuous mixing of incoming wastes. The disadvantages are high capital and operating costs and the need for trained personnel. Maintenance costs can also be high because of the abrasive characteristics of the waste and exposure of moving parts to high incineration temperatures.

A cement kiln incinerator is an option that can be used to incinerate most hazardous and non-hazardous wastes. The rotary kiln type is the typical furnace used in all cement factories. Rotary kilns used in the cement industry are much larger in diameter and longer in length than the previously discussed incinerator.

The manufacture of cement from limestone requires high kiln temperatures (1,400C) and long residence times, creating an excellent opportunity for hazardous waste destruction. Further, the lime can neutralize the hydrogen chloride generated from chlorinated wastes without adversely affecting the properties of the cement. Liquid hazardous wastes with high heat contents are an ideal supplemental fuel for cement kilns and promote the concept of recycling and recovery. As much as 40% of the fuel requirement of a well-operated cement kiln can be supplied by hazardous wastes such as solvents, paint thinners, and dry cleaning fluids. The selection of hazardous wastes to be used in cement kiln incinerators is very important not only to treat the hazardous wastes but also to reap some benefits as alternative fuel and alternative raw material without affecting both the product properties and gas emissions. However, if hazardous waste is burned in a cement kiln, attention has to be given to the compounds that may be released as air emissions because of the combustion of the hazardous waste. The savings in fuel cost due to use of hazardous waste as a fuel may offset the cost of additional air emission control systems in a cement kiln. Therefore with proper emission control systems, cement kilns may be an economical option for incineration of hazardous waste.

The rotary kiln gasifier is used in several applications, varying from industrial waste to cement production and the reactor accomplishes two objectives simultaneously: (1) moving solids into and out of a high temperature reaction zone and (2) assuring thorough mixing of the solids during reaction. The kiln is typically comprised of a steel cylindrical shell lined with abrasion-resistant refractory to prevent overheating of the metal and is usually inclined slightly toward the discharge port. The movement of the solids being processed is controlled by the speed of rotation of the kiln.

The moving grate gasifier is based on the system used for waste combustion in a waste-to-energy process. The constant-flow grate feeds the waste feedstock continuously to the incinerator furnace and provides movement of the waste bed and ash residue toward the discharge end of the grate. During the operation stoking and mixing of the burning material enhances distribution of the feedstocks and, hence, equalization of the feedstock composition in the gasifier. The thermal conversion takes place in two stages: (1) the primary chamber for gasification of the waste (typically at an equivalence ratio of 0.5) and (2) the secondary chamber for high temperature oxidation of the synthesis gas produced in the primary chamber (Grimshaw and Lago, 2010; Hankalin et al., 2011).

The rotary kiln ICM/Phoenix Bioenergy demonstration gasifier was operated at a transfer station in Newton, Kansas from 2009 to 2012 for more than 3200h, testing various types of biomass, RDF, tire-derived fuel or automobile shredded residue mixed with RDF. The 150-t-per-day facility reported to have tested more than 16 types of feedstock listed in Table 3.2 [13].

The gasification process consists of a horizontal cylinder with an internal auger which slowly rotates [15] allowing feedstock to move through the reactor, whereas air is injected at multiple points. Only small portion of the syngas was used to produce steam, whereas the rest was flared (Fig. 3.2).

Unfortunately, ICM had to take down the demonstration gasifier at the transfer station, upon completion of the project and financing grant, declaring that the facility did not prove to be a viable solution for the county. Some of the problems that ICM mention [16] were related to the availability of feedstock of only 90t per day, whereas the prototype was designed for 150t per day, but also insufficient investment from financial partners due to the lower projected returns. ICM announced that through a contract with the City of San Jose, CA they will have the ICM demonstration gasifier at the San Jos-Santa Clara Regional Wastewater Facility [17]. The facility will process 10 short tons per day of woody biomass, yard waste or construction and demolition materials mixed with biosolids from the WWT.

the difference in a rotary incinerator

the difference in a rotary incinerator

As the industries leading designers and manufacturers of incinerators we are able to provide solutions for all waste streams. If you do not see the industry you are looking for contact our sales team directly.

Although, the majority of machines that we manufacture are fixed chamber incinerators. There are occasions when considering a Rotary incinerator could be the right decision for you and your waste requirements. As every need is unique we would always recommend that if you have any questions that you let us help guide you to the best solution for you.

The main different in Rotary kiln incinerators consists of their cylindrical primary chamber that rotates or indexes on a set of motorised gears. As the waste load enters the kiln, rotation of this chamber provides agitation to the waste stream. This movement provides a turbulent environment, this then exposes un-combusted material that may have otherwise sat in the middle or the bottom of a load during the combustion process.

For this reason rotary kiln technologies are best suited to high moisture and/or low calorific waste streams, where dead zones and cold spots could be easily created from bulk entry of loads. As the primary chamber rotates, waste (and resulting ash) is encouraged to slowly move through the primary chamber towards the de-ashing outlet. Given that the wastes time in the primary chamber is limited by the rotation continual movement it is important to ensure:

1) The diameter, length and pitch of the primary chamber is of an adequate size/angle to provide a high-quality ash in which total organic components present in the ash less than <3% or <5% (depending on the waste type), by the time it reaches the ash drop out zone.

2) The sizing of the primary chamber is synchronised to the amount of revolution a primary chamber may undertake. A particularly low moisture, low calorific waste load will require more revolutions to ensure heat penetrates through the load, however more revolutions will mean the waste may travel faster than anticipated.

3) The correct diameter of the kiln can be governed by many factors, including burn rate and waste type. The volume of the chamber has to be consistent with the waste density loaded. 500kg of loose animal by-products may only take up 1m3 whereas 500kg of Municipal Solid Waste may take up 5m3 of space.

As such it is vitally important that each and every rotary incinerator is correctly designed and modelled prior to its construction. Where possible computational fluid dynamic (CFD) modelling, should be employed to confirm waste retention times in the primary chamber.

Rotary Kilns consist of the same major components of similar sized incinerators with only the primary chamber, inlet and outlet vestibules being considerably different. The primary chamber construction is typically cylindrical steel structure, with a refractory installation consisting in the majority of a high-grade refractory brick refractory. Orientation of burners and secondary chamber outlets can be specified as co-counter flows or as counter current flow.

As leading manufacturers in incinerators we are able to utilise our 35 years of experience into providing the right solution to your needs. Able to manage every aspect of the design and build in-house, where our sales and design engineers will develop the incinerator along your exact requirements through to our expert, welder fabricators, electricians and refractory masons ensuring that your incinerator is built to our exacting standards to deliver the results to safely dispose of your waste.

is it better to use refractory bricks or castables for the lining of rotary kiln incinerators?

is it better to use refractory bricks or castables for the lining of rotary kiln incinerators?

The service life of refractory bricks used in the lining of the rotary kiln incinerator will affect the normal production of the rotary kiln. Of course, there are also rotary kiln-type incinerators that use refractory castables for integral pouring. So, is it better to use refractory bricks or castables for the lining of rotary kiln incinerators?

The thermal stress generated by the rapid cooling and rapid heating of the rotary kiln-type incinerator affects the service life of the inner lining. If the refractory castable for the lining is mainly alumina, add a certain proportion of silicon carbide to prevent acid corrosion. Refractory castables used in rotary kilns are also prone to falling off of tuyere materials. The performance of the castable itself and the on-site construction quality control is not in place, which easily causes abnormalities in the rotary kiln equipment. Coupled with frequent start and stop, it will aggravate the falling off of the lining of the rotary kiln.

To solve the problem of the castable burst. According to the requirements of different castables, the amount of water added should be less than more. The addition of an explosion-proof agent to the castable can make the refractory castable form a mesh-shaped micro-crack channel in the matrix when the refractory castable is heated and dry, which increases the air permeability of the refractory castable.

Different parts of the rotary kiln have different temperature requirements during normal operation and use, and it is necessary to select refractory lining materials according to the requirements of each part. A 50 mm thick thermal insulation refractory is built close to the outer layer, a 180 mm thick high-temperature refractory castable is poured in the high-temperature calcination part, and a 180 mm thick ordinary refractory concrete is poured in other parts. This effectively prevents the lining from falling off, reduces the number of maintenance, and prolongs the life of the rotary kiln.

Commonly, the refractory castable for rotary kiln-type incinerators is easy to fall off, the lining life is short, the operation rate is low, and the production cost is high. Of course, the proportion of refractory bricks used in the refractory lining of rotary kiln-type incinerators will be higher than that of refractory castables.

The ratio of refractory bricks used in rotary waste incinerators is still higher than that of castables because of easy maintenance. Refractory bricks are sintered at a high temperature to perform better. But the material of bricks still needs to be cautious. Some users want to purchase silicon-molecular composite bricks for the refractory lining of incinerators. After analysis by refractory manufacturers, due to the bulk density of silicon-molecular composite bricks, in actual use, silicon-molecular composite bricks are not suitable for rotary waste incinerators.

So what kind of bricks are used in rotary waste incinerators? Refractory manufacturers recommend the use of anti-stripping high alumina bricks. With the addition of zirconia to the anti-stripping high alumina brick, it has high strength and resistance to acid and alkali corrosion, and its price is lower than that of silicon-mo composite bricks, and its service life is longer.

Regarding the selection of refractory lining materials for rotary kiln incinerators, whether it is to use refractory bricks or refractory castables, it is necessary to continuously summarize the experience in production practice. Strive for the best match between process and technical conditions, and finally achieve high-yield, high-quality, long-life, and low-cost efficient operation of the rotary kiln.

everything you need to know on rotary kiln refractory

everything you need to know on rotary kiln refractory

Refractory, or the lining utilized on the interior of rotary kilns, is a critical component in ensuring process efficiency and prolonging the life of a rotary kiln. Here, well discuss everything you need to know about refractory, including how it works, the different types, and best practices for preventative care.

Rotary kilns employ high temperatures to cause a chemical reaction or physical change in a material. In most cases, these high operating temperatures would immediately destroy an unprotected carbon steel shell. For this reason, refractory is used.

Only direct-fired rotary kilns employ refractory; in an indirect-kiln, heat transfer occurs primarily through the kiln shell wall. Refractory would be another barrier for heat to pass through before it is in contact with material, reducing the efficiency of the process. Because of this, instead of using refractory, indirect-fired kilns typically rely on a more heat resistant shell.

Further necessitating the need for refractory, direct-fired kilns typically do not utilize combustion chambers, so the flame is in constant direct contact with the internals. Flame temperature can typically range anywhere between 1600 3200 (depending on excess air) a harsh processing environment that carbon steel is not capable of withstanding.

As the skeleton of the system, protecting the shell is paramount to prolonging the life of the equipment; a major repair or total replacement of the shell is a substantial undertaking, requiring significant downtime and repair costs. For this reason, choosing the right refractory configuration and taking measures to protect that refractory once operational is critical.

While the main objective of refractory is to protect the kiln shell, refractory also serves to minimize heat loss. A kiln with sub-par refractory may protect the kiln shell, but allow significant heat loss, reducing overall process efficiency and increasing operational costs.

Castable refractory comes in a powder form and is mixed with water on-site. Before the mixture can be put in place, anchors are installed. These y-shaped anchors are similar to rebar in cement; they help give the castable lining its strength. Once these anchors are in place, the cement-like mixture is pumped into the lining of the rotary kiln, and allowed to cure for several days.

Castable refractory has a similar material cost to brick. However, brick installation is much more labor intensive, as each brick is individually installed. This makes the overall cost of a brick lining more expensive than castable.

Besides lower overall cost, the advantage to using castable refractory in a rotary kiln is that it is usually easily patched when a problem is encountered. Down time is typically minimal, because the problem area can be cut out and new refractory poured into the cavity.

The disadvantage to using castable refractory in a rotary kiln is that it is very susceptible to installation problems. When castable refractory is expertly installed, it can nearly match the quality of brick. But if installed incorrectly, there can be a considerable difference in quality, and the life of the refractory can be severely compromised.

Although slightly more expensive than castable, brick does not require anchors, and its quality is superior, but as mentioned, incurs greater install costs. When processing a highly abrasive material, brick refractory is advisable most of the time, as castable does not have the durability to stand up against abrasive materials as well as brick.

The disadvantage to brick refractory is that it is kept in place much like a roman arch: bricks are held in place by the pressure of the other bricks pushing against each other. When a problem is encountered, typically the failed brick needs to be replaced, but when one brick is relying on the bricks around it to hold it in place, often one cannot replace just one brick, and whole sections of the refractory must be replaced. Unlike castable refractory, the repair of a fail in brick refractory is much more involved.

There is more to refractory than just the choice of material; refractory is a customizable part of rotary kiln design and can be tailored with multiple layers to meet the demands of a given application.

When efficiency is of great concern, or when extreme temperatures are involved, it is common to employ both a working layer, and an insulating layer. Layer thickness can also vary, with total refractory thickness generally falling between 4.5 12, pending process temperatures..

The working layer is the layer of refractory that is in direct contact with the material being processed. This layer is a dense, durable lining designed to withstand the high temperatures within the rotary kiln, as well as the constant abrasion from the material.

When it comes to refractory, the more dense it is, the less insulating capabilities it has. This means that even though there may be a working layer in place, the heat can easily pass through it to the shell of the rotary kiln. For this reason, an insulating layer is needed beneath the working layer. The insulating layer serves as insulation to protect the shell of the rotary kiln so the high temperatures within cannot reach the shell and damage it.

Typically the working layer and the insulating layer are made of the same material (ie. brick or castable), with varying chemistries. The working layer tends to be a higher density, strongermaterial that is more conductive. The insulating layer does not need these qualities, and tends to be softer, lighter, and less conductive, therefore more insulating. These two layers often vary in thicknesses, determined by the needs of the rotary kiln and what material is being processed. In some cases, such as when temperatures are fairly low, or when efficiency is not a concern, a single working layer may be all that is needed.

In contrast, when insulation is extremely critical, an optional third layer of ceramic fiber backing may be used. This thin, but very efficient layer is similar to fiberglass insulation found in a house, but it is much more compressed. The decision to employ this layer comes with some responsibility. Should a crack in the refractory occur and go unnoticed, it is possible for the high heat inside the rotary kiln to reach this backing and burn it up. This would create a gap between the refractory and the shell of the rotary kiln, which would cause disastrous problems. Due to this potential of increased risk, this third layer is not always appropriate.

The processing environment within a direct-fired rotary kiln can be harsh. The combination of constant rotation, extreme temperatures, heavy loads, and abrasive and corrosive environments, has the potential to cause significant damage or catastrophic failure to a kilns shell. Once your rotary kiln refractory is installed and in use, it is important to take the extra steps to ensure it is properly maintained.

A well-installed, high quality refractory can have a lifespan of many years, but there are factors that can cut refractory life short. While early signs of refractory failure can be hard to spot, the good news is, many of the things that can cause refractory failure are preventable. The two primary causes of refractory failure are cycling and chemical incompatibility.

The biggest source of refractory failure is what is called cycling. Cycling is simply the heating up and cooling down of the rotary kiln. Each time the rotary kiln is heated, the refractory expands with the drum, and as the kiln is cooled, the refractory retracts. If a kiln is constantly being turned on and shut down, the refractory can easily become stressed, resulting in cracks.

Similarly, cracks can also occur from heating or cooling the kiln too quickly. To maximize refractory life, it is important to try to reduce cycling as much as possible, keeping shut downs to a minimum.

Chlorides can aggressively attack refractory, causing excessive wear because of their corrosive nature. When these chemicals are identified up front, refractory can be designed with this in mind to help reduce the potential for excessive wear. Similarly, unknown components in a material or a change in feedstock can also result in excessive wear on refractory.

Operators should be well-versed in the proper operation of the kiln and what to look for to spot potential problems. Operators and maintenance personnel should always follow the guidelines for safety and maintenance set forth by the original equipment manufacturer.

Regularly observing the kiln to check for any visual, auditory, or other abnormalities can mean the difference between a small repair and a catastrophic failure. As part of routine observations on the unit, the kiln shell should be regularly measured with a temperature gun to check for hot spots.

This can be done by picking a spot on the rotary kiln shell, and holding a temperature gun in place. As the rotary kiln rotates, that spot should read the same temperature for the entire circumference of the shell. For example, a temperature reading of 400, 400, 700, 400 would likely indicate a failure in refractory. Left untreated, this could lead to severe damage to the rotary kiln shell.

In addition to circumference temperature being the same in a given location, there should be a gradual shift in temperatures from one end of the kiln to the other, not a drastic change. Catching these problems early is important to minimizing the potential for damage.

Additionally, having a service technician visit the site to observe and inspect the kiln every so often is also considered best practice in preventative maintenance. Depending on what the original equipment manufacturer recommends, this is generally on an annual basis, but may be more frequent for especially demanding settings.

Refractory failure can have disastrous results. Even a small crack can allow heat to reach the rotary kiln shell. It is important to routinely temp gun the exterior of the rotary kiln shell, ensuring that the temperature is consistent for the entire circumference of the drum.

Refractory is a critical component in the design of a direct-fired rotary kiln, helping to protect the kiln shell from the harsh processing environment within. A customizable part of kiln design, refractory can be engineered to suit the unique needs of an application, with factors such as material and multiple layers coming into play.

As the only barrier between the shell and the kiln interior, protecting and maintaining refractory is of the utmost importance in order to prolong the life of the equipment and avoid potential catastrophic failures.

rotary kiln incineration systems - for individuals

rotary kiln incineration systems - for individuals

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rotary kiln incinerator companies and suppliers | energy xprt

rotary kiln incinerator companies and suppliers | energy xprt

Dutch Incinerators' specialism is the incineration business, and more in particular the thermal treatment of hazardous, chemical, toxic and (bio) medical waste streams. We build multipurpose incinerators that turn refuse waste into energy. Energy ...

Direct fired Rotary Kiln Incineration has been proven to be the Best Available Technique (BAT) for large scale waste disposal requirements and has become our preferred thermal treatment solution for ...

Dutch Incinerators' specialism is the incineration business, and more in particular the thermal treatment of hazardous, chemical, toxic and (bio) medical waste streams. We build multipurpose incinerators that turn refuse waste into energy. Energy ...

Wah Kok Professional Engineering Contractor is in the business of structural steel works, civil & mechanical engineering. It is also a Building & Construction Authority (BCA) registered contractor and a certied bizSAFE company. Mr. Tan Kock ...

WK-TWT has operated and improved uidized bed technology for many years: similar to gasication/pyrolysis, uidized bed can have specic advantages on dedicated waste streams. Although denitely not as versatile as ...

Wah Kok Professional Engineering Contractor is in the business of structural steel works, civil & mechanical engineering. It is also a Building & Construction Authority (BCA) registered contractor and a certied bizSAFE company. Mr. Tan Kock ...

WSEnergy is a fast growing company located in Bavaria, Germany. The company's areas of expertise lies in recycling, centrifugation and separation technologies. We offer to our clients customized advanced engineering and project-management ...

WSEnergy is a fast growing company located in Bavaria, Germany. The company's areas of expertise lies in recycling, centrifugation and separation technologies. We offer to our clients customized advanced engineering and project-management ...

IGNISS ENERGY - Incinerator design and manufacturer company. Our working structure for incinerator plant design and construction Process and software. This department is leaded by ex-plant managers of counter current rotary kilns for medical and ...

The rotary kiln incinerator is manufactured with a rotating combustion chamber that keeps waste moving, thereby allowing it to vaporize for easier burning. Types of waste treated in a ...

IGNISS ENERGY - Incinerator design and manufacturer company. Our working structure for incinerator plant design and construction Process and software. This department is leaded by ex-plant managers of counter current rotary kilns for medical and ...

We are a company dedicated to the Design, manufacturing and supply of equipment, plants and technology for heat recovery, air or gases heating, incineration, volatile organic compounds (VOC's) abatement, industrial heating and tobacco drying.From ...

We are a company dedicated to the Design, manufacturing and supply of equipment, plants and technology for heat recovery, air or gases heating, incineration, volatile organic compounds (VOC's) abatement, industrial heating and tobacco drying.From ...

Verantis is a global company dedicated to solving environmental control challenges. We design, fabricate, install and service a complete line of pollution control equipment including Scrubbers, Industrial FRP Blowers, Tellerette Tower Packing as ...

Complete flexibility to simultaneously dispose of liquids, solids, and sludges. Rotary kiln incineration systems are ideal for processing mixed industrial and hazardous wastes that include a ...

Verantis is a global company dedicated to solving environmental control challenges. We design, fabricate, install and service a complete line of pollution control equipment including Scrubbers, Industrial FRP Blowers, Tellerette Tower Packing as ...

ATC LLC. is established in 2000 and as of this date to do engineering, designing and manufacturing to provide turnkey solutions for industrial production, incinerators, gasifications, waste disposal management, waste to energy, waste sorting, energy ...

ATCINT manufacturing and installation with renewable energy to generate steam, hot water, thermal oil or electricity. Filtration systems guarantee an installation with new European Emission Standards, the most severe in the world Directive ...

ATC LLC. is established in 2000 and as of this date to do engineering, designing and manufacturing to provide turnkey solutions for industrial production, incinerators, gasifications, waste disposal management, waste to energy, waste sorting, energy ...

ATI was founded in 1930 by Maurice MULLER. ATI ENVIRONNEMENT designs and manufactures incinerators for waste treatment and filtration system. We are specialized in treatment of hospital and industrial wastes. All our installation respect the ...

propose you A range of rotary kiln with a capacity of destruction from 600 to 3000 kg / hour and thermal power from 2500 to 12000 kW per ...

ATI was founded in 1930 by Maurice MULLER. ATI ENVIRONNEMENT designs and manufactures incinerators for waste treatment and filtration system. We are specialized in treatment of hospital and industrial wastes. All our installation respect the ...

Maguin, renowned for its expertise in sugar technology, has in more recent years diversified its activities. Today the Company offers a full range of processes and equipment within four major areas: Beet Sugar Industry; Drying and screening of ...

The rotary kiln is able to process, with optimum results, all types of industrial waste including hazardous and non hazardous waste and hospital waste, whether it is in solid, paste or sludge ...

Maguin, renowned for its expertise in sugar technology, has in more recent years diversified its activities. Today the Company offers a full range of processes and equipment within four major areas: Beet Sugar Industry; Drying and screening of ...

We have researched the waste treatment technologies market in Europe for several years and gained a clear vision on the possibilities and opportunities within We offer consulting and corresponding services to assist private or public institutions ...

We have researched the waste treatment technologies market in Europe for several years and gained a clear vision on the possibilities and opportunities within We offer consulting and corresponding services to assist private or public institutions ...

Reaction Engineering International (REI) is a growing R&D consulting firm with an internationally recognized expertise in combustion and environmental solutions. We offer Consulting Services and Products to clients in the energy and environmental ...

CFS Configured Fireside Simulators are designed for use by engineers who are not experts in Computational Fluid Dynamics (CFD). CFS gives the real-world engineer the tools needed to optimize and analyze complex furnaces and boilers. ...

Reaction Engineering International (REI) is a growing R&D consulting firm with an internationally recognized expertise in combustion and environmental solutions. We offer Consulting Services and Products to clients in the energy and environmental ...

BIC Group is in the business of designing and supplying incineration and waste-to-energy systems for industrial waste streams. This kind of plant thermally oxidizes non-recyclable, hazardous waste streams and turns them into a wide variety of energy ...

BIC Group is in the business of designing and supplying incineration and waste-to-energy systems for industrial waste streams. This kind of plant thermally oxidizes non-recyclable, hazardous waste streams and turns them into a wide variety of energy ...

The Paul Wurth Group today is one of the world leaders in the design and supply of the full-range of technological solutions for the iron & steel industry and other metal sectors. With a consolidated expertise as a builder of complete plants and a ...

For the incineration and treatment of Municipal Solid Waste (MSW), RDF, sewage sludge, hospital waste or animal residues, Paul Wurth offers tailor-made plants, whose capacity ranges (per ...

The Paul Wurth Group today is one of the world leaders in the design and supply of the full-range of technological solutions for the iron & steel industry and other metal sectors. With a consolidated expertise as a builder of complete plants and a ...

We understand ourselves as a partner of both research and industry. In this way, we can develop sustainable and innovative solutions to translate latest scientific findings into industrial applications. Responsible acting to us means ensuring the ...

We understand ourselves as a partner of both research and industry. In this way, we can develop sustainable and innovative solutions to translate latest scientific findings into industrial applications. Responsible acting to us means ensuring the ...

VisionTIR is an international manufacturer of multispectral thermography systems for industrial non-contact temperature measurement, process monitoring, quality control and early fire detection. Our innovative solutions feature high quality and ...

VisionTIR is an international manufacturer of multispectral thermography systems for industrial non-contact temperature measurement, process monitoring, quality control and early fire detection. Our innovative solutions feature high quality and ...

Pollution Engineering is an environmental engineering Malaysian company established since 1980. The companys principal business activity is technology provider for wastewater (sewage treatment plant, industrial wastewater treatment plant, river and ...

PEMSB has the expertise to design and manufacture both rotary kiln and fixed bed type incinerators for both small and large scale applications. The incinerators are specially ...

Pollution Engineering is an environmental engineering Malaysian company established since 1980. The companys principal business activity is technology provider for wastewater (sewage treatment plant, industrial wastewater treatment plant, river and ...

Focus Environmental, Inc. specializes in providing process engineering, and regulatory compliance services in the areas of hazardous waste thermal treatment, air permitting, air pollution control, contaminated soil remediation and hazardous waste ...

Focus Environmental, Inc. specializes in providing process engineering, and regulatory compliance services in the areas of hazardous waste thermal treatment, air permitting, air pollution control, contaminated soil remediation and hazardous waste ...

Since 1982, HiTemp Technology Corporation (HTT) manufactures custom, high-temperature catalysts, fume incinerators and oxidizer systems featuring enclosed flares, rotary kilns and moving-earth scrubber systems to control methane gas emissions for ...

in one week. The unit shown in the attached pictures was delivered on Monday and in operation on Thursday morning the same week. The system is 12 Tons Per Day Rotary Kiln Incineration system for ...

Since 1982, HiTemp Technology Corporation (HTT) manufactures custom, high-temperature catalysts, fume incinerators and oxidizer systems featuring enclosed flares, rotary kilns and moving-earth scrubber systems to control methane gas emissions for ...

Henan Fote Machinery Ltd. (FTM) is a large-scale joint-stock enterprise mainly engaged in the production of heavy machinery. It has three large-scale manufacturing plants now. With scientific management , advanced manufacturing technology and ...

Rotary kiln is also known as calcining kiln, belonging to the building material equipment. According to the difference of processing material, rotary kiln can be ...

Henan Fote Machinery Ltd. (FTM) is a large-scale joint-stock enterprise mainly engaged in the production of heavy machinery. It has three large-scale manufacturing plants now. With scientific management , advanced manufacturing technology and ...

When the company L. & C. Steinmller started building steam boilers in 1874, thus decisively influencing the introduction and development of the modern steam boiler in Germany, the founders were clear about one thing: a company that wants to have a ...

The concept of hazardous waste incineration in a rotary kiln was developed more than 40 years ago and is still an ideal method for incinerating hazardous waste for throughputs of ...

When the company L. & C. Steinmller started building steam boilers in 1874, thus decisively influencing the introduction and development of the modern steam boiler in Germany, the founders were clear about one thing: a company that wants to have a ...

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