Claims:We claim:

1. An arrangement for acoustic control in metallic scrap chute comprising of :

at least one metallic scrap chute configured for transportation of scrap metal pieces; and
a continuous water chamber disposed below the base of scrap chute configured for dampening the vibration caused in the transportation of metal pieces wherein the water chamber extends to the side walls of the said scrap chute.

2. The arrangement as claimed in claim 1, wherein the water chamber is made up of 10mm mild steel plate.

3. The arrangement as claimed in claim 1, wherein there water chamber includes an inlet and outlet for water in the said water chamber.

4. The arrangement as claimed in claim 1, wherein paint is coated over the inner and outer for preventing corrosion.

5. The arrangement as claimed in claim 1, wherein the noise level is reduced to

91db and below.

Dated: this 22nd day of March, 2016.

(N. K. Gupta) Patent Agent, Of NICHE,
For SAIL.

To,
The Controller of Patents, The Patent Office, Mumbai.

, Description:

FORM 2

THE PATENTS ACT, 1970

(39 of 1970) COMPLETE SPECIFICATION (Section 10 and rule 13)

TITLE

ACOUSTIC CONTROL FOR SCRAP CHUTE

APPLICANT

STEEL AUTHORITY OF INDIA LIMITED, A GOVT. OF INDIA ENTERPRISE, BHILAI STEEL PLANT,
BHILAI - 490001, STATE OF CHATTISGARH, INDIA

The following specification particularly describes the nature of the invention and the manner in which it is to be performed

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ACOUSTIC CONTROL FOR SCRAP CHUTE

FIELD OF INVENTION:

The present invention relates to a device for acoustic control of scrap chutes at guillotine side trimming shear in plate mill of Bhilai Steel Plant .The noise level (>91 db) is generated due to fall of scraps on the metallic chutes. Workers at work place were exposed to high noise for eight hours. More particularly, the present invention relates to modified scrap chute for reducing noise level to below 91db using water chambers.

BACK GROUND OF THE INVENTION:

As with any occupational hazard, control technology should aim at reducing noise to acceptable levels by action on the work environment. Such action involves the implementation of any measure that will reduce noise being generated, and/or will reduce the noise transmission through the air or through the structure of the workplace.

Cooled and inspected plates are finished in required width as per customer demands. Plates are finished width wise in guillotine side trimming shear in plate mill at finishing zone. The function of guillotine side trimming shear is to trim the plates from both ends to get smooth and straight surface in transverse direction of plates. During the rolling process the excess meal around 50mm is given as trimming allowance, which will be trimmed as scraps during trimming process. Those trimmed scraps are cut into one meter long pieces and strike the metallic guided chutes. Sound is generated during hitting the chutes by scraps.The level of
sound are hazards for a healthy worker in eight hours exposure in sound.

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Such measures include modifications in the workplace operations. In fact, the best approach for noise hazard control in the work environment is to eliminate or reduce the hazard at its source of generation, either by direct action on the source or by its confinement. In certain cases, the solution may be found in a combination of measures which by themselves would not be enough; for example, to achieve part of the required reduction through environmental measures and to complement them with personal measures (e.g. wearing hearing protection for

only 2-3 hours), bearing in mind that it is extremely difficult to make sure that hearing protection is properly fitted and properly worn.

Thus there is a need for design a device which reduced the sound level for eight hours working exposure in sound without hazards.

During the rolling process the excess metal around 50mm is given as trimming allowance, which will be trimmed as scraps during trimming process.

Plates are cooled and finished, width wise in guillotine side trimming shear in plate mill at finishing zone. The function of guillotine side trimming shear is to trim the plates from both sides to get smooth and straight surface in transverse direction of plates. Those trimmed scraps are cut into one meter long pieces and they fall and hit the metallic guided chutes. Sound is generated due to hitting on the chutes by scrap pieces. The level of sound is hazards for a healthy worker for eight hours exposure.

Thus there is a need for a new design which can reduce the sound level for eight hours working.

OBJECT OF THE INVENTION:

The object of the invention is to reduce the noise level for eight hours working exposure without health hazards for worker.

Another aim of the invention is to improve the working efficiency for eight hours working exposure for a worker.

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SUMMARY OF THE INVENTION:

Noise is unwanted sound which can be arrested either at source or during its path of transmission including change of generating equipment. Engineering design mostly limit the replacement of equipment. Water, considered to be very effective dampener and this property is used here.

High noise is generated due to fall of scraps on the metallic chutes of guillotine side trimming shear before getting collected in the bin for disposal.

Here a device is designed & invented for reducing the sound level by dampening the noise generated, since inception of plate mill, in the metallic scrap chutes at guillotine side trimming shear.

Water jacketing of scrap chute is the principal logic behind this invention. The jacket is designed and MS plate is used for its fabrication.

There is an inlet in the water jacket which is connected to industrial water pipe line for filling. Regular check up for water level is being done.

It was observed that noise level has been reduced to 91db, which is 3db less

(Approx. 50% reduction) from the previous noise level.

Thus according to the present invention there is a designed a device for reducing the sound level in the metallic scrap chutes at guillotine side trimming shear in a plate mill.

Such as herein described there is provided, an arrangement for acoustic control in metallic scrap chute comprising of: at least one metallic scrap chute configured for transportation of scrap metal pieces; and a continuous water chamber disposed below the base of scrap chute configured for dampening the vibration caused in the transportation of metal pieces wherein the water chamber extends to the side
walls of the said scrap chute.

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Thin 10mm MS plates are used for making water chambers blow the metallic scrap chute on both sides of guillotine type side trimming shear at plate mill.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

Fig. 1 illustrates the arrangement of water chamber below the scrap chute and an inlet and an outlet for water in the said water chamber disposed in both sides of guillotine type side trimming shear at plate mill in accordance with the present system;

DETAILED DESCRIPTION

Herein disclosed is an arrangement for acoustic control for noise in scrap chutes at guillotine side trimming shear in a plate mill. The modified design is meant for reducing sound level, which generates due to falling of scraps on the metallic chutes of guillotine side trimming shear in plate mill for eight hours exposure in sound without hazards at work place for a worker.

Conventional conveying chutes generate external noise during operation. A primary source of noise during operation is the impact of metal against the walls of the chute, falling of scrap pieces on the metallic chutes, before collecting in bin. Additional noise is also created, in part, by the operation of the shear cutters. To reduce noise, it has been known to place an insulating shell around the exterior housings of conventional disposers. While the prior art technique reduces some of the noise emitted during operation of the disposer, further noise reduction is needed.

To achieve the above purpose, there is provided a continuous water-chamber, including the tank body, the tank body is provided below the scrap chute, located at guillotine side trimming shear in a plate mill as shown in Fig. 1. The chamber is fabricated with 10mm MS plate. U-shaped water level is provided below the scrap chute so as to dampen the noise produced during the fall of the metal pieces. The water chamber is designed and fabricated so as to include the maximum portion
of the bottom portion of the scrap chute including the side walls. The height of the

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water chamber by the side walls of the scrap chute is preferably from the middle portion.

As shown in Fig. 1, there is provided an inlet and an outlet for water in the said water chamber disposed in both sides of guillotine type side trimming shear at plate mill. It was observed that noise level has been reduced to 91db, which is
3db less from the previous noise level.

Thin MS plate was used for designing the water jackets and water is used as dampener. Regular check-up for water level is being done and further interior and exterior painting is required at regular intervals for the prevention from corrosion. The paint is to be applied with preferably two coats. The water jacket is connected to industrial water pipe line to fill with water. During operation it was experimentally observed that noise level has been reduced to 91db, which is 3db less from the previous noise level.

Although the foregoing description of the present invention has been shown and described with reference to particular embodiments and applications thereof, it has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the particular embodiments and applications disclosed. It will be apparent to those having ordinary skill in the art that a number of changes, modifications, variations, or alterations to the invention as described herein may be made, none of which depart from the spirit or scope of the present invention. The particular embodiments and applications were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such changes, modifications, variations, and alterations should therefore be seen as being within the scope of the present invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably
entitled.