Title of Invention	A METHOD & SYSTEM OF THERMAL RECLAMATION OF USED FOUNDRY SAND
Abstract	An improved thermal reclamation foundry sand system and method thereof comprising of a feeding arrangement for feeding of the sand, fluidized bed incinerator; said fluid bed incinerator consisting of a incinerator chamber, aperatures are provided at the bottom of the said incinerator for introducing the mixture of air and LPG and a burner for blowing of the said LPG in the said chamber; an input for feeding of sand to be reclaimed and a output for taking out the reclaimed sand; heat exchanger is provided at the said input for heating the sand to the predetermined temperature and another heat exchanger is provided at the output for cooling of the said reclaimed sand.

Title of Invention

A METHOD & SYSTEM OF THERMAL RECLAMATION OF USED FOUNDRY SAND

Abstract

An improved thermal reclamation foundry sand system and method thereof comprising of a feeding arrangement for feeding of the sand, fluidized bed incinerator; said fluid bed incinerator consisting of a incinerator chamber, aperatures are provided at the bottom of the said incinerator for introducing the mixture of air and LPG and a burner for blowing of the said LPG in the said chamber; an input for feeding of sand to be reclaimed and a output for taking out the reclaimed sand; heat exchanger is provided at the said input for heating the sand to the predetermined temperature and another heat exchanger is provided at the output for cooling of the said reclaimed sand.

Full Text	FORM 2 THE PATENT ACT, 1970, (39 OF 1970) & THE PATENTS RULE, 2003 Provisional Specification (See section 10 and rule 13) "Improved Thermal Reclamation Foundry Sand System and Method Thereof". Atre Ashok Dattatray Pushpa heights 1st floor, Bibwewadi corner, Pune-satara road, Pune-411037 Maharashtra, India An Indian National The Following Specification Describes the nature of the Invention FIELD OF THE INVENTION The invention herein described relates generally to systems and methods for thermally treating solid, granular and aggregate materials and, more particularly, to a system and method for reclaiming spent Resin bonded foundry sands. BACKGROUND OF THE INVENTION Various prior art attempts have been made to treat material by thermal reclamation and, in particular, foundry sand. The advantages of reclaiming foundry sand are well known. One advantage is the reduction in the need for virgin sand. In addition, the ability to reclaim used sand obviates the problem associated with the need to find a suitable disposal site for the used foundry sand. Due to the cost of virgin sand and the cost of disposal of used sand, and also due to the strict regulations which now exist governing the disposal of waste materials in land fill sites, foundries now wish to increase the level of reclaimed sand which they use. If sand is to be reclaimed successfully the reclamation process must not only restore the condition of the sand by breaking down agglomerates and removing particles of metal, but the process must also enable the reclaimed sand to be reused, preferably with the same type of binder as before. Insofar as the reclamation of used foundry sand is concerned, there are at least two major requirements, which from a practical standpoint, must be satisfied thereby. Namely, the used foundry sand after being subjected to the reclamation process must be in substantially the same condition as it originally was. That is, the reclamation process must be capable of returning the used foundry sand, in essence, to its original condition. Secondly, the reclamation of used foundry sand must be capable of being accomplished economically. More specifically, the cost of reclamation must be such that reclamation from a financial standpoint is sufficiently attractive to render it desirable to undertake the investment in terms of time, labour and money required thereby as compared to continuing to purchase new, i.e., not previously used, foundry sand. In one of the close prior art is patent application (145 / MUM / 2005) entitled, "THERMAL RECLAMATION FOUNDRY SAND SYSTEM AND METHOD" wherein a Fluidized bed sand reclamation needed fine sand as input, hence pulverizer was necessary which needs more electrical power. Air required for fluidization is introduced in the fluidization chamber without preheating. Heating of this air from ambient to incinerator temperature needs more energy. Hot sand is directly cooled in the fluidised Bed Cooler. The air required for the cooling is large. For this separate fluidised bed cooler, FD fan, cyclone, ID Fan and ducting are required. This demands higher electrical load as well as higher space. The high air flow rate also causes wear at the Cooler cyclone and ID fan needing intermittent replacement. Separate F.D. Fans for incinerator & cooler, hence increased power consumption. Two fluidisation chambers in the system, one for incineration & the other for cooling, hence more space requirement. A need exists for a foundry sand reclamation system and method that overcome drawbacks and limitations or prior art 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 efficiency. BREIF DESCRIPTION OF THE INVENTION The invention herein described relates generally to systems and methods for thermally treating solid, granular and aggregate materials and, more particularly, to a system and method for reclaiming spent Resin bonded foundry sands. The present invention mainly focuses on combination of manual and control operations for the sand reclamation process wherein improvements have been made while designing the new art sand reclamation system which enables net exporter of the usable heat and pays for itself. The entire process requires minimum energy inputs. The inventors of the present invention nullify the drawback of prior art by eliminating the need of the external fuel in the running condition. On the contrary plant is the net exporter of the heat which can be utilized elsewhere. There is a simplified fluidization system because of the elimination of the fuel gas injection through the fluidizing air manifold. The Required incineration temperature can be maintained either by regulating the air flow rate or sand input rate. Ease of using liquid fuels instead of only gaseous fuels. The sand cooling heat exchanger preheats the incoming air which is used for the fluidization. Bulk flow cooler is used for the sand cooling which minimizes the wear & tear. Water cooled rotary valves are provided for the hot sand. Further an improved fluid bed chamber can be provided with ceramic lining. There is a constant air flow rate instrumentation to give consistency in product output quality & quantity. With this system, 10 mm lumps can be incinerated reducing the input sand pulverization level. The process disclosed herein comprises of series of equipments coupled in order to carry out the sand reclamation wherein a lump crusher initiate the process which is used for reducing the large size sand lumps into smaller particles which further leading to magnetic separator which removes the magnetic particles before it is fed to the bucket elevator. Bucket elevator further delivers the sand into heat recovery column at the top, which further goes into the incinerator for processing. The heat from the hot flue gases coming out of the incinerator is recovered by heating the incoming sand by the counter flow hot exhaust gases in the heat recovery column. The Fluid Bed Incinerator is the heart of the system. It consists of a fluidized sand bed. Air is introduced at the bottom, through the tubes with appropriate holes giving necessary fluidization. Burner in the incinerator chamber generates the necessary heat to maintain the sand bed temperature as well as the required temperature to burn the volatile organics generated. The sand temperature is @ 600 to 650°C. The space above the sand has temperature of 800 to 1000 °C depending upon the type of resin. Here all the volatile organic gases liberated during the reclamation are burnt completely, making the exhaust pollution free. The hot reclaimed sand is send to the other Heat Exchanger with the help of ventury / rotary valve. The fuel Burner with necessary fuel input arrangement is provided. It is associated with Flame Monitor, Modulating Unit & other necessary safety equipments. In the Heat Exchanger for sand Cooling the hot sand from incinerator transfers heat to the incoming fresh air making it hot and cooling the sand partially. As air is getting heated in this heat exchanger, fuel economy is also improved. In the Bulk Flow Cooler the Sand from heat exchanger is further cooled using water as cooling medium. The rotary valves discharge the sand, without allowing air entry into the system. Rotary Valve below the BFC controls the level in the BFC with the help of level sensor in the top portion, ensuring that the BFC is always full with the sand and sufficient time is provided for the sand cooling. The gases are exhausted with the help of ID fan. Cyclone is provided after the incinerator to separate the fine particles from the exhaust gases. F. D. & I. D. fans are incorporated to supply & take out Air / gases from the system. Sieve Shakers are incorporated to remove the impurities in the input sand & to separate unwanted fraction in the reclaimed sand. Instrumentation & Control Panel is provided to operate the system in the desired manner with necessary safeties. Further the use of heat recovery equipment depends upon on the desired end application such as hot water generator, hot air generator, thermic fluid heater etc. In one of the embodiment of the invention the control System plays an important role as initially the system is operated in the manual mode stabilizing the required process parameters. Then it is put in Automatic control mode which operates as follows: Complete combustion of the resin takes place in the incinerator. Resin in the sand is the source of heat to maintain the incinerator outlet temperature. Hence for high resin sand the input is reduced & vice a versa, maintaining the incinerator outlet temperature. Hence for the high resin content sands the process is self sustaining & the burner remains off during the normal operation. Fuel consumption is controlled as per the exhaust temperature at the outlet of the incinerator. Adjustable weir at the sand outlet gives the facility of adjustable residence time for the sand. Air flow measurement orifice is provided at the inlet of the incinerator FD Fan. The pressure drop across this orifice is monitored by a pressure transmitter, generating the 4-20 mA electrical signal. This signal is given to the Variable Frequency Drive (VFD) which is controlling the FD Fan RPM. The incinerator chamber pressure is monitored by a pressure transmitter which gives signal to the ID fan VFD maintaining the required air flow in the system. Thus a constant air flow is maintained in the incinerator. Rotational speed of the rotary valve below Bulk Flow Cooler is controlled by the level sensor in the in the Bulk Flow Cooler. With this type of control fuel is not at all required once the steady state is achieved, and the system becomes the net exporter of the heat energy.

Full Text

FORM 2
THE PATENT ACT, 1970,
(39 OF 1970)
&
THE PATENTS RULE, 2003
Provisional Specification
(See section 10 and rule 13)
"Improved Thermal Reclamation Foundry Sand System and Method
Thereof".
Atre Ashok Dattatray Pushpa heights 1st floor, Bibwewadi corner, Pune-satara road, Pune-411037 Maharashtra, India An Indian National
The Following Specification Describes the nature of the Invention

FIELD OF THE INVENTION
The invention herein described relates generally to systems and methods for thermally treating solid, granular and aggregate materials and, more particularly, to a system and method for reclaiming spent Resin bonded foundry sands.
BACKGROUND OF THE INVENTION
Various prior art attempts have been made to treat material by thermal reclamation and, in particular, foundry sand. The advantages of reclaiming foundry sand are well known. One advantage is the reduction in the need for virgin sand. In addition, the ability to reclaim used sand obviates the problem associated with the need to find a suitable disposal site for the used foundry sand.
Due to the cost of virgin sand and the cost of disposal of used sand, and also due to the strict regulations which now exist governing the disposal of waste materials in land fill sites, foundries now wish to increase the level of reclaimed sand which they use.
If sand is to be reclaimed successfully the reclamation process must not only restore the condition of the sand by breaking down agglomerates and removing particles of metal, but the process must also enable the reclaimed sand to be reused, preferably with the same type of binder as before. Insofar as the reclamation of used foundry sand is concerned, there are at least two major requirements, which from a practical standpoint, must be satisfied thereby. Namely, the used foundry sand after being subjected to the reclamation process must be in substantially the same condition as it

originally was. That is, the reclamation process must be capable of returning the used foundry sand, in essence, to its original condition. Secondly, the reclamation of used foundry sand must be capable of being accomplished economically. More specifically, the cost of reclamation must be such that reclamation from a financial standpoint is sufficiently attractive to render it desirable to undertake the investment in terms of time, labour and money required thereby as compared to continuing to purchase new, i.e., not previously used, foundry sand.
In one of the close prior art is patent application (145 / MUM / 2005) entitled, "THERMAL RECLAMATION FOUNDRY SAND SYSTEM AND METHOD" wherein a Fluidized bed sand reclamation needed fine sand as input, hence pulverizer was necessary which needs more electrical power. Air required for fluidization is introduced in the fluidization chamber without preheating. Heating of this air from ambient to incinerator temperature needs more energy. Hot sand is directly cooled in the fluidised Bed Cooler. The air required for the cooling is large. For this separate fluidised bed cooler, FD fan, cyclone, ID Fan and ducting are required. This demands higher electrical load as well as higher space. The high air flow rate also causes wear at the Cooler cyclone and ID fan needing intermittent replacement. Separate F.D. Fans for incinerator & cooler, hence increased power consumption. Two fluidisation chambers in the system, one for incineration & the other for cooling, hence more space requirement.
A need exists for a foundry sand reclamation system and method that overcome drawbacks and limitations or prior art 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 efficiency.
BREIF DESCRIPTION OF THE INVENTION
The invention herein described relates generally to systems and methods for thermally treating solid, granular and aggregate materials and, more particularly, to a system and method for reclaiming spent Resin bonded foundry sands.
The present invention mainly focuses on combination of manual and control operations for the sand reclamation process wherein improvements have been made while designing the new art sand reclamation system which enables net exporter of the usable heat and pays for itself. The entire process requires minimum energy inputs.
The inventors of the present invention nullify the drawback of prior art by eliminating the need of the external fuel in the running condition. On the contrary plant is the net exporter of the heat which can be utilized elsewhere. There is a simplified fluidization system because of the elimination of the fuel gas injection through the fluidizing air manifold. The Required incineration temperature can be maintained either by regulating the air flow rate or sand input rate. Ease of using liquid fuels instead of only gaseous fuels. The sand cooling heat exchanger preheats the incoming air which is used for the fluidization. Bulk flow cooler is used for the sand cooling which minimizes the wear & tear. Water cooled rotary valves are provided for the hot sand. Further an improved fluid bed chamber can be provided with ceramic lining. There is a constant air flow rate instrumentation to give consistency in product output

quality & quantity. With this system, 10 mm lumps can be incinerated reducing the input sand pulverization level.
The process disclosed herein comprises of series of equipments coupled in order to carry out the sand reclamation wherein a lump crusher initiate the process which is used for reducing the large size sand lumps into smaller particles which further leading to magnetic separator which removes the magnetic particles before it is fed to the bucket elevator. Bucket elevator further delivers the sand into heat recovery column at the top, which further goes into the incinerator for processing. The heat from the hot flue gases coming out of the incinerator is recovered by heating the incoming sand by the counter flow hot exhaust gases in the heat recovery column. The Fluid Bed Incinerator is the heart of the system. It consists of a fluidized sand bed. Air is introduced at the bottom, through the tubes with appropriate holes giving necessary fluidization. Burner in the incinerator chamber generates the necessary heat to maintain the sand bed temperature as well as the required temperature to burn the volatile organics generated. The sand temperature is @ 600 to 650°C. The space above the sand has temperature of 800 to 1000 °C depending upon the type of resin. Here all the volatile organic gases liberated during the reclamation are burnt completely, making the exhaust pollution free. The hot reclaimed sand is send to the other Heat Exchanger with the help of ventury / rotary valve. The fuel Burner with necessary fuel input arrangement is provided. It is associated with Flame Monitor, Modulating Unit & other necessary safety equipments.

In the Heat Exchanger for sand Cooling the hot sand from incinerator transfers heat to the incoming fresh air making it hot and cooling the sand partially. As air is getting heated in this heat exchanger, fuel economy is also improved. In the Bulk Flow Cooler the Sand from heat exchanger is further cooled using water as cooling medium.
The rotary valves discharge the sand, without allowing air entry into the system. Rotary Valve below the BFC controls the level in the BFC with the help of level sensor in the top portion, ensuring that the BFC is always full with the sand and sufficient time is provided for the sand cooling. The gases are exhausted with the help of ID fan. Cyclone is provided after the incinerator to separate the fine particles from the exhaust gases. F. D. & I. D. fans are incorporated to supply & take out Air / gases from the system. Sieve Shakers are incorporated to remove the impurities in the input sand & to separate unwanted fraction in the reclaimed sand.
Instrumentation & Control Panel is provided to operate the system in the desired manner with necessary safeties. Further the use of heat recovery equipment depends upon on the desired end application such as hot water generator, hot air generator, thermic fluid heater etc.
In one of the embodiment of the invention the control System plays an important role as initially the system is operated in the manual mode stabilizing the required process parameters. Then it is put in Automatic control mode which operates as follows:
Complete combustion of the resin takes place in the incinerator. Resin in the sand is the source of heat to maintain the incinerator outlet temperature. Hence for high resin sand the input is reduced & vice a versa, maintaining the

incinerator outlet temperature. Hence for the high resin content sands the
process is self sustaining & the burner remains off during the normal
operation.
Fuel consumption is controlled as per the exhaust temperature at the outlet of
the incinerator.
Adjustable weir at the sand outlet gives the facility of adjustable residence
time for the sand.
Air flow measurement orifice is provided at the inlet of the incinerator FD Fan.
The pressure drop across this orifice is monitored by a pressure transmitter,
generating the 4-20 mA electrical signal. This signal is given to the Variable
Frequency Drive (VFD) which is controlling the FD Fan RPM. The incinerator
chamber pressure is monitored by a pressure transmitter which gives signal to
the ID fan VFD maintaining the required air flow in the system. Thus a
constant air flow is maintained in the incinerator.
Rotational speed of the rotary valve below Bulk Flow Cooler is controlled by
the level sensor in the in the Bulk Flow Cooler.
With this type of control fuel is not at all required once the steady state is
achieved, and the system becomes the net exporter of the heat energy.

Documents:

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Patent Number

269958

Indian Patent Application Number

1631/MUM/2007

PG Journal Number

47/2015

Publication Date

20-Nov-2015

Grant Date

20-Nov-2015

Date of Filing

24-Aug-2007

Name of Patentee

ATRE ASHOK DATTATRAY

Applicant Address

PUSHPA HEIGHTS 1ST FLOOR, BIBWEWADI CORNER, PUNE-SATARA ROAD, PUNE

Inventors:

#	Inventor's Name	Inventor's Address
1	ATRE ASHOK DATTATRAY	PUSHPA HEIGHTS 1ST FLOOR, BIBWEWADI CORNER, PUNE-SATARA ROAD, PUNE 411037

PCT International Classification Number

B22C5/08; B22C5/18; F27B7/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA