Title of Invention	SELF CLEANING PROCESS OF THE POWDER FEED HOPPER FOR THE POWDER SPRAY BOOTH
Abstract	A self-cleaning method or process of the powder feed hopper for the powder spray booth during the colour changing action comprising. A quick color changeable hopper placed on the floor of a vestibule attached to the main spray module of a powder coating booth. Keeping the vestibule door of the spray module opened and the front door of the spray module closed shut. Starting the fan in the recovery section, to cause the entire air flow to pass through the vestibule, causing substantial air flow over the top of the hopper. Initially opening the dump port of hopper to allow bulk of the powder in the hopper to drop into powder container beneath the hopper and closing the same after the hopper getds empty. High pressure compressed vortex air completely cleans the hopper, blowing the residue powder out of the open top of the hopper into the draft of air rushing into the booth through the vestibule door. Sucking the dislodged residue powder in the hopper into the spray booth"s recovery system.

Title of Invention

SELF CLEANING PROCESS OF THE POWDER FEED HOPPER FOR THE POWDER SPRAY BOOTH

Abstract

A self-cleaning method or process of the powder feed hopper for the powder spray booth during the colour changing action comprising. A quick color changeable hopper placed on the floor of a vestibule attached to the main spray module of a powder coating booth. Keeping the vestibule door of the spray module opened and the front door of the spray module closed shut. Starting the fan in the recovery section, to cause the entire air flow to pass through the vestibule, causing substantial air flow over the top of the hopper. Initially opening the dump port of hopper to allow bulk of the powder in the hopper to drop into powder container beneath the hopper and closing the same after the hopper getds empty. High pressure compressed vortex air completely cleans the hopper, blowing the residue powder out of the open top of the hopper into the draft of air rushing into the booth through the vestibule door. Sucking the dislodged residue powder in the hopper into the spray booth"s recovery system.

Full Text	This invention relates to a self-cleaning method or process of the powder feed hopper for the powder spray bo6th during the colour changing action process and a self-cleaning powder feed hopper for the Powder Spray Booth for carrying out the process. More particularly, the invention relates to a low cost self-cleaning powder feed hopper that can be cleaned and prepared for spraying a new colour quickly and with little human intervention*. Prior Art While changing colour in a powder spraying process, one of the key pieces of equipment that needs to be thoroughly cleaned is the powder feed hopper. Given the large surface areas of typical hoppers and the finely divided nature of the powder particles, traditional hoppers are difficult to clean. The cleaning process is slow and labour intensive. Often it is avoided altogether by dedicating one hopper to each colour. This is an expensive option and contributes in placing the otherwise attractive powder coating process beyond the reach of small and medium enterprises. Objects of this invention The primary object of this invention is to have the powder feed hopper thoroughly cleaned while changing the colour in a powder spray process. The second object of this invention is to achieve a quick cleaning of the hopper, thereby keeping the downtime due to cleaning minimal. The third object of this invention is to achieve self-cleaning of the hopper by blowing the compressed air causing a vortex of air to be developed inside the hopper thus getting the whole area cleaned. The fourth object is to keep the surrounding area clean by using the suction of the booth to remove the powder cloud generated during the self cleaning of the hopper. statement of Invention A low cost self-cleaning powder feed hopper that can be cleaned and prepared for spraying a new colour quickly and with little human intervention. The powder feed hopper is constructed from a standard plastic pipe. The fluidizing tile in the bottom of the hopper has a concentric circular opening, the dump port. On one side of the hopper is a tangential air inlet. In operation, the open top of the hopper is covered with a lid, with a powder pump mounted on it. The entire hopper assembly is mounted in a circular opening in the floor of a vestibule leading into the booth. A door at the vestibule entry is closed while powder is being sprayed in the booth Colour change is initiated by a quick dump of the bulk of the powder. The remaining adherent powder is r«moved by first increasing the fluidizing air pressure and then injecting high velocity compressed air tangentially into the cylindrical hopper. This dislodges the remaining powder. The dislodged powder is then sucked into the booth"s powder recovery system. Thus according to this invention a self-cleaning method or process of the powder feed hopper for the powder spray booth during the colour changing action comprising, i) Keeping the vestibule door of the spray module opened and the front door of the spray module closed shut; ii) Starting the fan in the recovery section, to cause the entire air flow to pass through the vestibule, causing substantial air flow over the top of the hopper; iii) Initially opening the dump port of hopper to allow bulk of the powder in the hopper to drop into powder container beneath the hopper and closing the same after the hopper gets empty; iv) High pressure compressed air is injected tangentially into the hopper, causing a vortex of air to develop inside it; v) High pressure compressed vortex air completely cleans the hopper, blowing the residue powder out of the open top of the hopper into the draft of air rushing into the booth through the vestibule door; vi) Sucking the dislodged residue powder in the hopper into the spray « booth"s recovery system. According to another feature of this invention, a self-cleaning method or process of the powder feed hopper for the powder spray booth during the colour changing action process wherein, at the step (iv), the fluidized air pressure is then increased to and maintained at 4 bar. Thus according to this invention, a self-cleaning powder feed hopper for the powder spray booth comprises of, a powder recovery suction module mounted above the powder spray module; said powder spray booth connecting to a vestibule through a door on one side and having a front door on the other side; said hopper is mounted in the floor of the said vestibule connected to the powder spray module, having a fluidizing tile at its bottom, housing an opening at the center, to function as dump port connecting to a powder container; said hopper being connected to powder pump mounted on it through top which is being covered with a lid; said hopper on its one side having an air inlet to receive compressed air for self-cleaning while changing colour in a powder spray process. According to another feature of this invention, a self-cleaning powder feed hopper for the powder spray b®oth, wherein the said hopper is mounted on the bottom floor of the vestibule connected to the powder spray module through a door. According to yet another feature of this invention, a self-cleaning powder feed hopper for the powder spray booth, wherein the hopper is provided with a fluidized tile having a circular opening at its center. According to yet another feature of this invention, a self-cleaning powder feed hopper for the powder spray booth, wherein the circular opening in the fluidized tile of the hopper is concentric. According to yet another feature of this invention a self-cleaning powder feed hopper for the powder spray booth, wherein, the air inlet is tangential to the cylindrical surface of the hopper to receive high-pressure compressed air. The invention will now be described in greater detail with reference to the accompanying drawings wherein the Fig.1 shows cut away view of the self-cleaning powder feed hopper Fig.2 shows Powder spray booth showing the assembly of powder feed hopper. Description of the invention During the colour change process the-vestibule door is opened and the front door of the booth is closed shut. The fan in the recovery section is started up, causing the entire air flow to pass through the vestibule. This results in a substantial air flow over the top of the hopper. The lid of the hopper is opened and placed in a bracket meant for this purpose. The dump port is opened allowing the bulk of the powder in the hopper to drop into a powder container beneath. The dump port then closes. (Both manual and automatic options are available.) The fluidizihg air pressure is then Increased to 4 bar. At the same time, high pressure compressed air is introduced tangentially into the hopper, causing a vortex of air to develop inside it. Together, these two steps result in the hopper getting completely cleaned. The powder is blown out of the open top of the hopper into the draft of air rushing into the booth through the vestibule door. All the powder from the hopper is thus sucked into the booth, and the hopper is completely cleaned without any additional steps. We claim:- 1. A self-cleaning process of the powder feed hopper for the powder spray booth during the colour changing action comprising, i) A quick color changeable hopper placed on the floor of a vestibule attached to the main spray module of a powder coating booth ii) Keeping the vestibule door of the spray module opened and the front door of the spray module closed shut; ill) Starting the fan in the recovery section, to cause the entire air flow to pass through the vestibule, causing substantial air flow over the top of the hopper; iv) Initially opening the dump port of hopper to allow bulk of the powder in the hopper to drop into powder container beneath the hopper and closing the same after the hopper gets empty; v) High pressure compressed air is injected tangentially into the hopper, causing a vortex of air to develop inside it; vi) High pressure compressed vortex air completely cleans the hopper, blowing the residue powder out of the open top of the hopper into the draft of air rushing into the booth through the vestibule door; vii)Sucking the dislodged residue powder in the hopper into the spray booth"s recovery system. 2. A self-cleaning process of the powder feed hopper for a powder spray booth during a colour changing action process as claimed in claim 1, wherein the fluidized air pressure is increased to 4 bar and it is maintained. 3. A self-cleaning powder feed hopper for the powder spray booth comprising, a powder recovery suction module mounted above the powder spray module; said powder spray booth connecting to a vestibule through a door on one side and having a front door on the other side; said hopper is mounted in the floor of the said vestibule connected to the powder spray module, having a fluidizing tile at its bottom, housing an opening at the center, to function as dump port connecting to a powder container; said hopper being connected to powder pump mounted on it through top which is being covered with a lid; said hopper on its one side having an air inlet to receive compressed air for self-cleaning while changing colour in a powder spray process. 4. A self-cleaning powder feed hopper for the powder spray booth as claimed in claim 3, wherein the said hopper is mounted on the bottom floor of the vestibule connected to the powder spray module through a door. 5. A self-cleaning powder feed hopper for the powder spray booth as claimed in claims 3&4, wherein the hopper is provided with a fluidized tile having a circular opening at its center. 6. A self-cleaning powder feed hopper for the powder spray booth as claimed in claim 5, wherein the circular opening in the fluidized tile of the hopper is concentric. 7. A self-cleaning powder feed hopper for the powder spray booth as claimed in claims 3 to 5, wherein the air inlet is tangential to the cylindrical surface of the hopper to receive high-pressure compressed air. 8. A self-cleaning powder feed hopper for the powder spray booth substantially as herein described and as illustrated in the accompanying drawings.

Full Text

This invention relates to a self-cleaning method or process of the powder feed hopper for the powder spray bo6th during the colour changing action process and a self-cleaning powder feed hopper for the Powder Spray Booth for carrying out the process. More particularly, the invention relates to a low cost self-cleaning powder feed hopper that can be cleaned and prepared for spraying a new colour quickly and with little human intervention*.
Prior Art
While changing colour in a powder spraying process, one of the key pieces of equipment that needs to be thoroughly cleaned is the powder feed hopper. Given the large surface areas of typical hoppers and the finely divided nature of the powder particles, traditional hoppers are difficult to clean. The cleaning process is slow and labour intensive. Often it is avoided altogether by dedicating one hopper to each colour. This is an expensive option and contributes in placing the otherwise attractive powder coating process beyond the reach of small and medium enterprises.
Objects of this invention
The primary object of this invention is to have the powder feed hopper thoroughly cleaned while changing the colour in a powder spray process.
The second object of this invention is to achieve a quick cleaning of the hopper, thereby keeping the downtime due to cleaning minimal.
The third object of this invention is to achieve self-cleaning of the hopper by blowing the compressed air causing a vortex of air to be developed inside the hopper thus getting the whole area cleaned.
The fourth object is to keep the surrounding area clean by using the suction of the booth to remove the powder cloud generated during the self cleaning of the hopper.

statement of Invention
A low cost self-cleaning powder feed hopper that can be cleaned and prepared for spraying a new colour quickly and with little human intervention.
The powder feed hopper is constructed from a standard plastic pipe. The fluidizing tile in the bottom of the hopper has a concentric circular opening, the dump port. On one side of the hopper is a tangential air inlet. In operation, the open top of the hopper is covered with a lid, with a powder pump mounted on it. The entire hopper assembly is mounted in a circular opening in the floor of a vestibule leading into the booth. A door at the vestibule entry is closed while powder is being sprayed in the booth
Colour change is initiated by a quick dump of the bulk of the powder. The remaining adherent powder is r«moved by first increasing the fluidizing air pressure and then injecting high velocity compressed air tangentially into the cylindrical hopper. This dislodges the remaining powder. The dislodged powder is then sucked into the booth"s powder recovery system.
Thus according to this invention a self-cleaning method or process of the powder feed hopper for the powder spray booth during the colour changing action comprising,
i) Keeping the vestibule door of the spray module opened and the front
door of the spray module closed shut; ii) Starting the fan in the recovery section, to cause the entire air flow to
pass through the vestibule, causing substantial air flow over the top of
the hopper; iii) Initially opening the dump port of hopper to allow bulk of the powder in
the hopper to drop into powder container beneath the hopper and
closing the same after the hopper gets empty; iv) High pressure compressed air is injected tangentially into the hopper,
causing a vortex of air to develop inside it;

v) High pressure compressed vortex air completely cleans the hopper, blowing the residue powder out of the open top of the hopper into the draft of air rushing into the booth through the vestibule door;
vi) Sucking the dislodged residue powder in the hopper into the spray
«
booth"s recovery system.
According to another feature of this invention, a self-cleaning method or process of the powder feed hopper for the powder spray booth during the colour changing action process wherein, at the step (iv), the fluidized air pressure is then increased to and maintained at 4 bar.
Thus according to this invention, a self-cleaning powder feed hopper for the powder spray booth comprises of, a powder recovery suction module mounted above the powder spray module; said powder spray booth connecting to a vestibule through a door on one side and having a front door on the other side; said hopper is mounted in the floor of the said vestibule connected to the powder spray module, having a fluidizing tile at its bottom, housing an opening at the center, to function as dump port connecting to a powder container; said hopper being connected to powder pump mounted on it through top which is being covered with a lid; said hopper on its one side having an air inlet to receive compressed air for self-cleaning while changing colour in a powder spray process.
According to another feature of this invention, a self-cleaning powder feed hopper for the powder spray b®oth, wherein the said hopper is mounted on the bottom floor of the vestibule connected to the powder spray module through a door.
According to yet another feature of this invention, a self-cleaning powder feed hopper for the powder spray booth, wherein the hopper is provided with a fluidized tile having a circular opening at its center.
According to yet another feature of this invention, a self-cleaning powder feed hopper for the powder spray booth, wherein the circular opening in the fluidized tile of the hopper is concentric.

According to yet another feature of this invention a self-cleaning powder feed hopper for the powder spray booth, wherein, the air inlet is tangential to the cylindrical surface of the hopper to receive high-pressure compressed air.
The invention will now be described in greater detail with reference to the accompanying drawings wherein the
Fig.1 shows cut away view of the self-cleaning powder feed hopper
Fig.2 shows Powder spray booth showing the assembly of powder feed hopper.
Description of the invention
During the colour change process the-vestibule door is opened and the front door of the booth is closed shut. The fan in the recovery section is started up, causing the entire air flow to pass through the vestibule. This results in a substantial air flow over the top of the hopper.
The lid of the hopper is opened and placed in a bracket meant for this purpose. The dump port is opened allowing the bulk of the powder in the hopper to drop into a powder container beneath. The dump port then closes. (Both manual and automatic options are available.)
The fluidizihg air pressure is then Increased to 4 bar. At the same time, high pressure compressed air is introduced tangentially into the hopper, causing a vortex of air to develop inside it. Together, these two steps result in the hopper getting completely cleaned. The powder is blown out of the open top of the hopper into the draft of air rushing into the booth through the vestibule door. All the powder from the hopper is thus sucked into the booth, and the hopper is completely cleaned without any additional steps.

We claim:-
1. A self-cleaning process of the powder feed hopper for the powder spray
booth during the colour changing action comprising,
i) A quick color changeable hopper placed on the floor of a vestibule
attached to the main spray module of a powder coating booth ii) Keeping the vestibule door of the spray module opened and the front
door of the spray module closed shut; ill) Starting the fan in the recovery section, to cause the entire air flow to
pass through the vestibule, causing substantial air flow over the top of
the hopper; iv) Initially opening the dump port of hopper to allow bulk of the powder in
the hopper to drop into powder container beneath the hopper and
closing the same after the hopper gets empty; v) High pressure compressed air is injected tangentially into the hopper,
causing a vortex of air to develop inside it; vi) High pressure compressed vortex air completely cleans the hopper,
blowing the residue powder out of the open top of the hopper into
the draft of air rushing into the booth through the vestibule door; vii)Sucking the dislodged residue powder in the hopper into the spray
booth"s recovery system.
2. A self-cleaning process of the powder feed hopper for a powder spray
booth during a colour changing action process as claimed in claim 1,
wherein the fluidized air pressure is increased to 4 bar and it is
maintained.

3. A self-cleaning powder feed hopper for the powder spray booth comprising, a
powder recovery suction module mounted above the powder spray module;
said powder spray booth connecting to a vestibule through a door on one side
and having a front door on the other side; said hopper is mounted in the floor
of the said vestibule connected to the powder spray module, having a
fluidizing tile at its bottom, housing an opening at the center, to function as
dump port connecting to a powder container; said hopper being connected to
powder pump mounted on it through top which is being covered with a lid;
said hopper on its one side having an air inlet to receive compressed air for
self-cleaning while changing colour in a powder spray process.
4. A self-cleaning powder feed hopper for the powder spray booth as claimed in
claim 3, wherein the said hopper is mounted on the bottom floor of the
vestibule connected to the powder spray module through a door.
5. A self-cleaning powder feed hopper for the powder spray booth as claimed in
claims 3&4, wherein the hopper is provided with a fluidized tile having a
circular opening at its center.
6. A self-cleaning powder feed hopper for the powder spray booth as claimed in
claim 5, wherein the circular opening in the fluidized tile of the hopper is
concentric.
7. A self-cleaning powder feed hopper for the powder spray booth as claimed in
claims 3 to 5, wherein the air inlet is tangential to the cylindrical surface of the
hopper to receive high-pressure compressed air.
8. A self-cleaning powder feed hopper for the powder spray booth substantially
as herein described and as illustrated in the accompanying drawings.

Documents:

442-che-2006 abstract.pdf

442-che-2006 claims duplicate.pdf

442-che-2006 claims.pdf

442-che-2006 correspondence others.pdf

442-che-2006 correspondence po.pdf

442-che-2006 description (complete) duplicate.pdf

442-che-2006 description (complete).pdf

442-che-2006 drawings.pdf

442-che-2006 form-1.pdf

442-che-2006 form-18.pdf

442-che-2006 form-26.pdf

442-che-2006 form-9.pdf

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Patent Number

221679

Indian Patent Application Number

442/CHE/2006

PG Journal Number

37/2008

Publication Date

12-Sep-2008

Grant Date

01-Jul-2008

Date of Filing

13-Mar-2006

Name of Patentee

NORDSON INDIA PRIVATE LTD

Applicant Address

143A BOMMASANDRA INDUSTRIAL AREA, BANGALORE 560 009,

Inventors:

#	Inventor's Name	Inventor's Address
1	AJIT KRISHNAN	NO.341 EMBASSY MEADOWS, S.T. BED LAYOUT, KORAMANGALA, BANGALORE 560 034,
2	M. MUTHUKUMAR	244, 3rd CROSS, 12th MAIN, 4th BLOCK, KORAMANGALA, BANGALORE 560 034,

PCT International Classification Number

B65G 65/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA