Title of Invention

"AN IMPROVED THERMAL RECLAMATION FOUNDRY SAND SYSTEM "

Abstract

A super efficient energy conserving thermal reclamation foundry sand system comprising a fluidised bed sand resin incinerator and a direct contact heat recovery heat exchanger column arranged one above the other; the said heat recovery column having an input for the cold sand which falls in the said fluidised sand incinerator; the said fluidised sand incinerator provided with plurality of openings at the bottom for introducing the mixture of fluidising air and gaseous fuel for initial startup and heating of the said sand incinerator to required temperature for removal of the organic material from the sand; arrangement of the said sand incinerator and a-direct ensures full the heat recovery.

Full Text

FROM 2 THE PATENTS ACT, 1970 (39 OF 1970) & THE PATENTS RULES, 2003 Complete specification (see section 10 and rule 13) A SUPEREFFICIENT ENERGY CONSERVING THERMAL RECLAMATION FOUNDRY SAND SYSTEM. MR. ATRE ASHOK DATTATRYA "PUSHPA HEIGHTS", 1ST FLOOR, BIBWEWADI CORNER, PUNE SATARA ROAD PUNE-411037. AN INDIAN NATIONAL The following specification particularly describes the invention and the manner in which it is to be performed 18 JUL 2005 Field of the invention Present invention relates to a superefficient energy conserving thermal reclamation system of foundry sand. More particularly present invention relates to the foundry sand reclamation system having no need of fuel input after stabilizing the system and very little need of external fuel only during cold start and till the system is stabilised. The invention involves unique method of embodying heat recovery feature in the form of heating the incoming cold sand itself through a direct contact heat exchanger in which incoming sand is preheated through utilizing heat from outgoing hot gases from the plant.. Prior art In foundries & other similar industries polymer or resin coated as well as virgin sand is consumed in huge quantities for different moulding purposes. The virgin sand is re-used after pouring of the castings. But the sand used in core making is coated with resins or polymers so that it can be moulded & cured to required shape having necessary strength. Polymers / resins impart necessary adhesiveness & adhesive strength to the sand particles to render mouldability, strength & dimensional stability. After pouring of the castings, these cores are broken down. This sand has partially burnt resins and cores also retain their shapes. Hence this type of sand cannot be re -used unless the pieces are broken down & resins are completely burnt. The used resin coated sand is a potential pollution hazard if dumped as landfill and hence its disposal has to be done only after ensuring that resin is completely destroyed in an eco-friendly manner. Also due ever increasing demand for foundry products, demand for resin coated sand is continuously increasing. Dredging and excavation of sand from sea beds and river beds is causing rapid soil erosion, shifting of river beds, loss of aquatic life etc. It is also known that the Resin coated sand is not biodegradable. From discarded polymer / resin coated sand, the polymer mixes with the soil and affects its quality. It can also percolate into river sand sub-soil waters. Drawing fresh sand from the river bed does result into soil erosion. Thus, used polymer coated sand cannot be used again in the foundry without reclaiming. Therefore it was the logical conclusion that the polymer must be removed effectively from used sand to enable recovery of sand for recoating / reuse. Hence there is a strong and urgent need to recover sand in reusable form from used resin coated foundry sand, so that the problem of dumping such sand is eliminated as well as demand for fresh sand is reduced. Recovery and reuse of sand also saves in a big way transport costs of fresh sand as well as resin coated sand. The key requirements from the process to be engaged for recovery sand are, 1) Energy efficiency should be high so that energy cost of recovering the sand is reasonable and affordable. 2) Complete destruction of resins without causing air pollution. 3) Consistency in quality of recovered sand. 4) Process should be able to handle reasonable fluctuations in properties of used sand being processed such as percentage resin in sand, sand bulk density , sand partial size, feed rate variations etc. 5) Proper automation of plant to cater to above situations so that plant is user friendly and consistent in its performance. If any of the above requirements cannot be met then recovery of sand and pollution abatement becomes uneconomical and unfriendly. Following are the prior methods or prior Art used for the reclamation of the foundry sand. 1. Attrition process is used for reclamation of some specific type of resin coated sand . 2. Rotary kiln type sand incinerators (resin incinerators !) 3. Fluidized bed Type incinerator (resin incinerators !) Deficiencies in the Prior Art: 1. Attrition Process : > It can be used for some limited varieties. > Requires large electrical energy inputs > Generates high sound pollution > Resins separated need to be destroyed or disposed through a separate plant > Resin removal is almost always partial and incomplete. > Output sand quality is therefore not consistent > Poor automation > High mechanical maintenance and frequent repairs. > Down time for repairs and maintenance is high. 2. Rotary kiln type > Very poor energy efficiency > Very big plant size for the given capacity. Occupies very large space. > High mechanical maintenance. > Poor automation. > Very high starting and stopping losses > Long time needed for reaching steady state after cold start. 3. Fluidized bed Type > High energy consumption. > Fully automatic operation control not available. > No heat recovery or very limited heat recovery from the exhaust heat available. > Even though fluidised bed incineration is used in this prior art, hot air generation for fluidization and incineration is done in a separate equipment away from the sand bed and then it is passed through the sand bed, requiring higher start up time and longer residence time of the sand for incineration. This adds to energy inefficiency, it also calls for frequent maintenance. > Over all process is not energy efficient since very small portion of the heat generated by burning of the resin and fuel is recovered and put to use. > Heat recovery is in the form of combustion Air Preheating (instead of incoming Sand Preheating which is the case in present invention). Air to air indirect heat exchanger used for heat recovery causes frequent failures and maintenance problems due to high air temperature heat exchange. It is well known that high temperature heat exchanger components are highly vulnerable to failures related to Thermal fatigue, cyclic thermal stresses due to temperature fluctuations that take place under varying operating conditions which do happen in thermal sand reclamation systems due to fluctuating resin percentage and its composition, Thermal cyclic stresses also are caused due to frequent starting and stopping of plants. High temperatures also cause stress corrosion at welded joints and in locations where metal has undergone shape change due to metal forming or machining. In an indirect heat exchanger, once the heat transfer tubes or heat exchanger components fail, plant has to be stopped and major downtime becomes compulsory resulting in large loss of plant availability and huge costly complicated maintenance. > Little or limited automatic control to take care of fluctuations in input parameters or operating conditions. > No automatic fluidization and combustion air flow rate control & no monitoring of CO gas in exhaust. (Carbon Monoxide in flue gas) Therefore, there was a urgent need to innovate a new process or method to reclaim and re-use polymer / resin coated sand. A need existed for a foundry sand Thermal reclamation system and method that will overcome drawbacks and limitations or prior art of foundry sand reclamation systems and methods. Principally, there is a need for such a system and method that provides high production output at low cost with high reliability and energy efficiency. It has been experienced for long time that the heat inputs involved in the process of Thermal reclamation of sand are enormous and large portion of the heat generated during the process goes waste unless high cost complicated maintenance prone air to air heat exchangers are incorporated and which in any case give only limited heat recovery. SUMMERY OF THE PRESENT INVENTION It is the object of the present invention to develop the foundry sand thermal reclamation system and method. It is also the object of the present-invention to develop the foundry sand thermal reclamation system and method embodying best and highest possible heat recovery feature easy to use, through heating the incoming cold sand itself by outgoing hot exhaust gases in a novel direct contact heat exchanger. The objective was also to develop a system which is simple to operate and maintain. The objective was to develop a elaborate fully automatic continuous monitoring control system that will ensure smooth, safe, reliable, energy efficient automatic operation of plant under all expected fluctuating conditions like, variation in resin percentage in sand, sand bulk density, sand particle size, sand feed rates etc. It is also the object of the present invention to overcome the drawbacks and deficiencies of the prior art. According to this invention, therefore, a super efficient energy conserving thermal reclamation foundry sand system comprising a fluidised bed sand resin incinerator and a direct contact heat recovery heat exchanger column arranged one above the other; the said heat recovery column having an input for the cold sand which falls in the said fluidised sand incinerator; the said fluidised sand incinerator provided with plurality of openings at the bottom for introducing the mixture of fluidising air and gaseous fuel for initial startup and heating of the said sand incinerator to required temperature for removal of the organic material from the sand; arrangement of the said sand incinerator and a direct ensures full the heat recovery. Further according to this invention a super efficient energy conserving thermal reclamation foundry sand system wherein the said heat recovery column is provided with alternate plates removably attached to the opposite inner surfaces at an angle which is higher than angle of repose with respect to the horizontal for directing the falling sand and allowing required residence time to heat the sand. Description of the invention The invention will now be described with reference to the drawings of the accompanying specification and refer to appropriately by numerals in the following specification. Figure 1 is the system for the preparation of input sand for incineration in the incinerator. Figure 2 is the fluidized bed resin incinerator, afterburner to destroy Volable Organic Compounds (VOCs) and heat recovery system according to the present invention (which is one of the main parts of the invention). The figure 2 also shows important schematics of the full automation of the incinerator, afterburner and its functions. Figure 3 is the sand cooler and heat recovery components according to the present invention. Figure 4 is sieve shaker and storage of the sand. Referring to the figure 1 the system consists of a sand pulverizer (1) which delumps &, crushes & pulverises the used foundry sand into fine powder. The said fine powder of the foundry sand is then passed over the magnetic separator (2) for removal of magnetic impurities like iron etc. Whenever needed, metal detectors and tramp material separators also can be provided. The sand which is obtained after passing through the said magnetic separator (2) is then carried and stored in to the input silo (4) by means of bucket elevator (3). Referring to figure 2 the stored sand from the said input silo (4) is fed to the thermal reclamation foundry sand system through screw conveyor used as sand feeder (5) in a controlled manner by changing rotational speed of screw feeder through variable frequency drive provided therein on its motor. The speed of the sand feeder can be controlled automatically as well as manually with the manual override. If the application demands other feeding devices like vibratory feeders, belt feeders etc also can be used alongwith necessary feed control systems like Variable Frequency Drive etc. The said foundry sand system consists of direct contact heat recovery heat exchanger column (6) provided above the sand incinerator (7) such that the outgoing sand from the said heat recovery column (6) falls in the sand incinerator (7). The said sand incinerator is fluidized bed type, in which air and LPG (Liquid Petroleum Gas) mixture is introduced at the bottom of the sand incinerator. This itself fluidizes the sand. LPG gas is ignited by firing the pilot burner to raise the sand temperature to the required temperature typically of 700°C or as required by different grades of resin. LPG gas train (12) having various controls supplies the necessary gas at.steady pressure which can be manually set and is also provided with safety mountings. There is also provision of a continuously modulating butterfly valve (11) for supply of additional air flow which enables the complete burning of the CO (Carbon Monoxide) which is otherwise a hazardous gas for human beings and also causes pollution. Normally such CO gas is not expected to get generated in the incinerator since adequate combustion Air including certain excess quantity over the stoichiometric requirements is supplied, but due to varying resin percentage in sand and varying degree of burntout condition of sand, fluctuations are expected to take place. The modulating butterfly valve feeds automatically the additional required air whenever needed which in turn supplies required oxygen to convert CO in to C02 (Carbon Dioxide). The plant is versatile in design to accept many alternate gaseous fuels like Natural Gas, Biogas, Producer gas, Blast furnace gas, Water gas, City gas, Butane, Propane etc etc. The plant design also can be run equally efficiently on vapors of vaporised liquid fuels like kerosene, diesel fuels, alcohols etc. Depending upon the fuels, certain components of fuel preparation system are changed which are of peripheral nature. The needed fuel preparation and handling systems are readily available. The sand temperature is maintained typically at about 700° C (Centigrade) or as required by different grades of resins and the temperature of exhaust gas above the sand is maintained at 1000° C for required residence time of oversafe value of three seconds when actual required value is maximum two seconds considering all grades of resins normally required to be burnt in such plant. This reliably ensures complete and total burning of all the volatile organic gases liberated during the reclamation. The heat from the hot flue gases coming out of the said sand incinerator (7) is fully and completely recovered by heating the incoming sand by the counterflow heat exchanger with hot exhaust gases in the said direct contact heat recovery column heat exchanger (6). Additional LPG burner called "afterburner" is provided above the sand bed to burn additional LPG to maintain the temperature of 1000° C. The afterburner is operational only during startup and till the system is not fully stabilised at normally working parameter from cold start condition or whenever the heat of combustion of resin is inadequate to reach 1000°C at desired productivity levels or sand throughout rates. Heat recovery column is provided with alternate plates removably attached to the opposite inner surfaces at an angle which is higher than angle of repose with respect to the horizontal for directing the falling sand and allowing required residence time to heat the sand. In the process of sand falling from top to bottom and coming in contact with hot gas flowing from lower to upper portion of the heat exchanger the said sand gets heated to temperature of 340 to 350°C and the out going gases are cooled from 1000°C to the lowest possible temperature of 190 to 200°C. By bringing down temperature of these gases from typically 1000°C to 200°C full recovery of heat which would have otherwise got wasted is put to use in heating up incoming sand. If this heat would not have been recovered, external fuel other than resin itself, would have been required increasing the running energy cost of the plant. Saving of such external fuel is one of the main inventions of this new art. The said cooled gas is passed through the dust separation cyclones (9) to separate the dust from the air before the air is exhausted through the Induced Draft (I.D) fan (8). The heated sand falls in the fluidized bed. Further, the burning of the sand resin in the fluidized bed itself maintains the sand temperature of 700°C or above and simultaneously maintains incinerator gas temperature of 1000°C or above or to the required value needed to completely destroy volatile organic compounds (VOCs) or gases generated during resin combustion. This is automatically controlled through a fully automatic control system narrated herein below in section "operation of the control system". Now referring to figure 3 and 4 the reclaimed sand is taken to the sand cooler (14) to cool the sand to about 50-80° C depending upon the use of the sand. The sand in the said sand cooler (14) is cooled by fluidization of sand with the help of ambient air. The hot air coming out from the said sand cooler (14) is passed through the dust separation cyclone (17) provided to separate the dust from the air before the air is exhausted through the I.D fan (16). The cooled sand from the said sand cooler (14) is then carried to the output silo (21) by means of another bucket elevator (20) provided therein. A vibrating sieve is provided to separate unwanted fraction in the reclaimed sand. Depending upon the needs of the specific site, the sand could also be transferred by other alternate material handling means like screw conveyors, belt conveyors etc. The cyclone separator provided for cleaning hot gases and hot air, if found inadequate for certain applications, could be replaced with bag filters provided with bags of fabric suitable to withstand the hot gas and hot air temperatures. The material handling and storage facilities mentioned / shown in figures 1 & 4 are representative only or typical facilities. They can also be provided with other alternative handling systems like screw conveyors, belt conveyors etc, choice of which is made depending upon suitability with respect to site conditions, plant layout possibilities, local facilities available, user preferences etc. Operation of the control System: Initially system is operated in the manual mode for reaching and stabilizing the required process parameters. Then it is put in Automatic control mode which operates as follows: The incinerator outlet temperature control is ensured with a continuous stepless modulation field adjustable PID (Proportional, Integrated and Derivative) Control which varies the rotational speed of the screw feeder by changing RPM (Revolutions per minute) of its motor through Variable Frequency Drive (VFD) for controlling the input sand quantity. Heat of combustion of resin in the sand is the source of heat to maintain the incinerator to required flue gas temperature of 1000°C. Hence for high resin content in sand the input gets automatically adjusted (reduced or increased), to maintain the incinerator outlet temperature, without any external energy input, i.e. the firing of afterburners and LPG supply normally remain totally off during the automatic mode of operation after initial stabilization the plant. Utilizing only the heat of combustion of resin for reaching 1000°C temperature of exhaust gas also increases combustion rate of resin thereby increasing inbed residence time of sand measured subsequent to sand reaching 600°C temperature in the bed. Increased residence time of sand ensures complete thermal stabilization of sand which is an essential requirement or property for reusing sand for foundry application again. In addition to the sand input VFD control, the high and low limits of PID controller also control the LPG solenoid valve to put on and off the LPG firing in bed and LPG firing in afterburner to maintain the required temperature of sand bed and the gas temperature above bed respectively whenever the conditions so demand due to variation in sand conditions, resin percent in sand etc. A CO (carbon monoxide) monitor (sensor) is also provided on the said incinerator chamber outlet. This gives signal to the motorised continuous modulation operated independent inlet air damper to give regulated additional air for complete combustion of the CO. The PID control modulates the additional air quantity for complete combustion of CO, by continuously sensing the actual CO level and comparing it with set point and then increasing the air supply if required. A pneumatic cylinder operated on-off type butterfly damper is provided to automatically open or close the air supply duct for CO control system. The capacity of fluidizing air blower is sized adequately to meet all above requirements. Air flow measurement orifice plate is provided at the inlet of the incinerator Forced Draft (FD) Fan. The pressure drop across this orifice, which indicates the actual airflow rate, is monitored by a pressure transmitter, which generates electrical signal in the range of 4 to 20 m A. This signal is given through PID controller to the Variable Frequency Drive (VFD) which adjusts and controls the FD Fan speed (RPM) such that a constant fluidization air flow is maintained to the incinerator. Hence fluidisation is achieved even with varying flow rates of the sand, sand bed height, changing bulk density etc. The incinerator chamber pressure is controlled and monitored continuously in stepiess manner through a control system in which furnace chamber pressure is sensed by a pressure transmitter which gives signal to Variable Frequency Drive (VFD) provided on I/D fan which adjusts the fan rotational speed to maintain the required air flow in the system. With all above control systems working together external fuel like LPG is not required at all, once the steady state is achieved, and in fact the system becomes the net exporter of utilizable heat energy, which can be used in process plant for meeting various needs. Additional Safeties & Interlocks: The plant is provided with several special and standard safety instruments with their control interlocks for reliable safe operation of the plant. Standard safeties like fuses, overload relays, relay interlocks, motor control relays etc although provided adequately, wherever required, are not described here because they are of standard construction. Only special safety interlocks are narrated herebelow. 1. LPG supply in the fluidizing air is cut off, as soon as the sand temperature reaches the desired minimum temperature needed and set on the set point. 2. LPG Burner gas is cut off once the incinerator outlet temperature goes above 1000°C. 3. Valve proving system fitted on the Gas Train, cuts off the LPG, if solenoid valve leakage is observed. 4. CO sensor continuously automatically monitors the incinerator flue gas and brings into operation and modulation the additional air inlet system provided at the FD fan inlet, preventing the CO formation. Main features and Advantages of the present invention: 1. Extremely low energy consumption : • Energy inputs are required only for initial heat up of the system • Afterwards plant can be set in fully automatic control mode with no external fuel energy input requirements 2. Full Use of the heat recovered from hot sand during cooling of the sand in sand cooler by: • Directly using the hot air for dryers or such applications. • As heat source for driving heat recovery equipments for generation of i. Hot water ii. Process steam iii. Thermic Fluid Heater (Hot oil generator) iv. Hot air generator v. To drive heat driven Absorption Chillers. 3. The plant is therefore a net exporter of the usable heat and pays for itself making it not only eco-friendly but also investor friendly system. 4. Fully automatic incineration control to take care of fluctuations in : • Resin percentage in the sand • Sand particle size distribution • Sand bed height variations • Sand feed rate 5. The instrumentation, control system & automation is so engineered that the super efficient energy conservation features are practically realised or realizable under varying operating conditions, feed parameters & different sand properties. 6. Reliable incineration temperature control to ensure complete destruction of resin & Volatile Organic Components (VOCs) that may or are likely to get generated during first stage of the resin combustion. 7. Liberal residence time provided for complete resin combustion and after burning of VOCs in afterburner section. 8. Supportive heat addition provided only when required through afterburner by Gas burning or vaporised fuel Oil burners as per availability of the fuel. 9. Fuel versatility due to possibility of burning wide range of gaseous fuels like LPG, Natural Gas, Bio Gas, producer gas, water gas, city gas, blast furnace gas, butane propane etc. for fuel Combustion in fluidised sand bed for cold start up of the plant. Vapors of Vaporized liquid fuels like kerosene, Diesel fuels, Alcohols etc. of liquid fuels can also be used, wherever needed 10. Thoroughly well instrumented for proper operation, monitoring, control & ease of maintenance of the plant. All important parameters can be observed & monitored. 11. Increase in inbed residence time of sand measured after the sand reaches 600°C temperature. This ensures complete thermal stabilization of sand required for reuse of sand in foundry application. A typical case study is presented in Table 1 to indicate the additional earnings and total cost savings from present invention as compared to prior Art. Energy savings given in Table 2 are taken into account in Table 1 while computing total additional earnings from present invention. These tables give typical values. These figures are likely to change from case to case due to local costs of fuel, percentage of resin in sand, type of resin etc. In any case the additional savings or additional earnings from present invention will always be far higher as compared to prior art. Typical Case Study: Table 1 Typical Comparative total cost savings and additional earnings by present Invention over prior Art Prior Art Prior Art Present Invention Reclamation Process Rotary kiln . Process Fluidized Bed Process present invention Process Indian Rupees per Ton 1 Purchase cost of new sand 1200 1200 1200 2 Drying Cost for new sand (@ 5 % moisture) 100 100 100 3 Net Cost of New Sand After Drying 1368 1368 1368 4 Disposal cost of used sand 100 100 100 5 Total cost without reclamation 1468 1468 1468 ( New Sand + Disposal cost) 6 Cost of thermal reclamation Electrical Running 100 100 100 LPG Running 600 300 Nil 7 Total 700 400 100 C re ost saving with 90 % sand covery 692 962 1232 8 Savings due to Heat Recovery Nil Nil 332 Refer Table 2 attached herewith 9 Net Savings per Ton of Sand Reclaimed 692 962 1563 10 Net additional earnings by present invention in one year based on 8000 hrs per year and for one ton per hour output plant in Rupees per year. For other output rates, additional earnings will be proportionate. Net additional earnings by Present Invention over Rotary Kiln process Rs. 6968000/- Net additional earnings by Present Invention over Fluidised Bed process Rs. 4808000/- Table 2 Typical energy Savings due to use of Super efficient, Energy conserving, Thermal Sand Reclamation Plant Quantity of Sand Reclaimed Kg / Hr 1000 Typical Resin Concentration % 2.5 Total Resin Quantity Kg/Hr 25 Typical Resin Calorific Value ( NCV) Kcal / Kg 6500 Total Heat Generated Kcal / Hr 162500 10 Heat Utilization in percentage of Heat Generated % 90 Net Heat Saved Kcal / Hr 146250 Furnace Oil Calorific Value ( NCV) ] Kcal / Kg 9700 Qty of Fuel Saved Kg/Hr 15.1 Cost of the Fuel Rs. / Kg 22 Savings Rs. /Ton 332 20 Hrs / Day 6634 19900 300 Days / Year 1990206 1000 Rs. Lakhs / Ton / Year 20 Resin Type considered : Phenolic Resin Resin Formula : C 26 H 3o O 3 I Claim:- 1. A super efficient energy conserving thermal reclamation foundry sand system comprising a fluidised bed sand resin incinerator and a direct contact heat recovery heat exchanger column arranged one above the other; the said heat recovery column having an input for the cold sand which falls in the said fluidised sand incinerator; the said fluidised sand incinerator provided with plurality of openings at the bottom for introducing the mixture of fluidising air and gaseous fuel for initial startup and heating of the said sand incinerator to required temperature for removal of the organic material from the sand; arrangement of the said sand incinerator and a-direct ensures full the heat recovery. 2. A super efficient energy conserving thermal reclamation foundry sand system as claimed in claim 1 wherein the said heat recovery column is provided with alternate plates removably attached to the opposite inner surfaces at an angle which is higher than angle of repose with respect to the horizontal for directing the falling sand and allowing required residence time to heat the sand. 3. A thermal foundry sand reclamation system as claimed in claim 1 wherein the said heat recovery column is provided with the cyclone for removing the dust particles form the air. 4. A thermal foundry sand reclamation system as claimed in 1 and 2 wherein there is provided a magnetic separator before the heat recovery column for separating the magnetic particles from the sand. 5. A thermal foundry sand reclamation system as claimed in claims 1 to 3 wherein there is provided a pulverizer before the said magnetic separator for breaking the sand into pieces. 6. A thermal foundry sand reclamation system as claimed in claims 1 to 4 wherein there is provided a screw feeder between the heat recovery column and magnetic separator. 7. A thermal foundry sand reclamation system as claimed in claims 1 to 5 wherein bucket elevator are provided to carry the sand form magnetic separator to screw feeder to heat recovery column-and sand cooler to output silo. 8. A super efficient energy conserving thermal reclamation foundry sand system as claimed in claims 1 to 6 wherein there is provided a sieve shaker to separate unwanted fraction in the reclaimed sand. 9. A super efficient energy conserving thermal reclamation foundry sand system as claimed in claims 1 to 7 wherein the plant is provided with various safeties and automatic controls for the smoother operation of the plant under varying operating conditions, feed parameters and resin percentage in sand etc etc. 10. A super efficient energy conserving thermal reclamation foundry sand system as claimed in claim 1 to 8 wherein.an air modulation system is provided for supply of additional air to the incinerator, for complete combustion of the CO if formed. 11. A thermal foundry sand reclamation system as claimed in claims 1 to 9 wherein complete thermal stabilization of sand gets ensured, 12. A thermal foundry sand reclamation system as claimed in claims 1 to 9 and as herein described with reference to the drawings of the accompanying specification. Dated this 18th day of July 2005. M. S. Khadilkar (Agent for Applicant)

Documents:

145-MUM-2005-ABSTRACT(26-12-2013).pdf

145-MUM-2005-ABSTRACT-230115.pdf

145-MUM-2005-AMENDED PAGES OF SPECIFICATION-230115.pdf

145-mum-2005-claims(18-07-2005).pdf

145-mum-2005-claims(19-11-2005).doc

145-MUM-2005-CLAIMS(AMENDED)-(26-12-2013).pdf

145-MUM-2005-CLAIMS(AMENDED)-230115.pdf

145-MUM-2005-CORRESPONDENCE(10-9-2013).pdf

145-MUM-2005-CORRESPONDENCE(11-2-2009).pdf

145-MUM-2005-CORRESPONDENCE(2-4-2013).pdf

145-mum-2005-correspondence(24-11-2005).pdf

145-MUM-2005-CORRESPONDENCE(27-12-2010).pdf

145-MUM-2005-CORRESPONDENCE(30-5-2013).pdf

145-MUM-2005-CORRESPONDENCE(8-8-2013).pdf

145-MUM-2005-DESCRIPTION(18-7-2005).pdf

145-MUM-2005-DESCRIPTION(PROVISIONAL)-(11-2-2005).pdf

145-mum-2005-drawing(18-07-2005).pdf

145-MUM-2005-DRAWING(26-12-2013).pdf

145-MUM-2005-DRAWING-230115.pdf

145-mum-2005-form 1(11-02-2005).pdf

145-MUM-2005-FORM 1(26-12-2013).pdf

145-MUM-2005-FORM 1-110215.pdf

145-MUM-2005-FORM 13(26-12-2013).pdf

145-MUM-2005-FORM 13-230115.pdf

145-MUM-2005-Form 13-300115.pdf

145-MUM-2005-FORM 18(11-2-2009).pdf

145-mum-2005-form 2(complete)-(18-07-2005).pdf

145-mum-2005-form 2(complete)-(19-11-2005).doc

145-MUM-2005-FORM 2(PROVISIONAL)-(11-2-2005).pdf

145-MUM-2005-FORM 2(TITLE PAGE)-(26-12-2013).pdf

145-MUM-2005-FORM 2(TITLE PAGE)-(COMPLETE)-(18-7-2005).pdf

145-MUM-2005-FORM 2(TITLE PAGE)-(PROVISIONAL)-(11-2-2005).pdf

145-MUM-2005-FORM 2(TITLE PAGE)--230115.pdf

145-mum-2005-form 26(11-02-2005).pdf

145-mum-2005-form 3(18-07-2005).pdf

145-MUM-2005-FORM 3(26-12-2013).pdf

145-mum-2005-form 5(18-07-2005).pdf

145-MUM-2005-FORM 5(26-12-2013).pdf

145-mum-2005-form 9(29-11-2005).pdf

145-MUM-2005-MARKED COPY(26-12-2013).pdf

145-MUM-2005-MARKED COPY-230115.pdf

145-MUM-2005-REPLY TO EXAMINATION REPORT(26-12-2013).pdf

145-MUM-2005-REPLY TO HEARING-110215.pdf

145-MUM-2005-REPLY TO HEARING-230115.pdf

145-MUM-2005-SPECIFICATION(AMENDED)-(26-12-2013).pdf

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