Claims:WE CLAIM:

1. Arrangement for cooling of skids and posts pipes in reheating furnace through closed loop soft water circuit comprising of :
a flushing arrangement using a plurality of Audco valves incorporated in outlet line of cooling circuit configured for regular flushing of pipes to flush out mud material, avoid steam formation and consequent bursting of pipes.

2. The arrangement as claimed in claim 1, wherein the said flush out mud material through valves causes significant reduction in the down time of Furnaces resulting in improved productivity due to elimination of the leakage in Skid and Post pipes.

3. The arrangement as claimed in claim 1, wherein the said valve causes arresting of water leakage from Skid and Post pipes and eliminating any disturbance caused to the temperature inside the Furnaces.

4. The arrangement as claimed in claim 1, wherein the said Audco Valve ensure flush out safety and provide clean cellar floor.
, Description:PROVISION OF THE FLUSHING PIPE LINE ALONG WITH AUDCO VALVE AT RETURN LINE OF BOTH RE-HEATING FURNACE, FOR SAVING THE SKID AND POST CONNECTING PIPE LINE FROM DAMAGES

FIELD OF INVENTION

The present invention relates to improved cooling of Skids and Posts Pipes in Reheating Furnace. More particularly the present invention relates to a flushing arrangement using Audco valves incorporated in outlet line of closed loop cooling circuit for regular flushing of pipes to flush out mud material.

BACKGROUND ART

Hot Strip Mill of Rourkela Steel Plant produces saleable steel like hot rolled coil catering to external customers like Tube, Cycle, Automobile industries, Railways, Industrial flooring etc. It is also an input material for downstream customers in the plant, like Cold Rolling Mill producing Cold rolled sheets catering to household appliances, furniture, fabrication, drum and barrels, tube making, cycle industries, Railways, agricultural equipment packing, coating etc, Silicon Steel Mill producing CRNO sheet catering to Electric Motors, Transformers, Rotating electrical machineries, Laminations etc, & Pipe Plants producing pipes catering to oil and natural gas sector like oil, gas and water transportation, slurry transportation, ash handling, construction, sewerage etc.

There are 2 nos. of Walking Beam Re-heating Furnaces (5 & 6) with a capacity of

225 Ton/Hr each. Slabs are charged in Re-heating Furnace for proper heating and soaking as well as smooth rolling. After charging, the movement of Slabs inside the Furnace takes place by movement of Walking Beams called Movable Skid & Post Pipes (4 nos.) and 4 nos. of fixed Skid & Post Pipes on which slabs rest while in stationary state.

In Re-heating Furnace, water cooling arrangement provided for skid pipes and post pipes. Soft water enters through inlet side and comes out at outlet side, then it is

returned back to return line. It is a continuous water flow process to skid & post pipe to protect from high temperature (about 13300 cg). The flushing of Skid & Post Pipes requires that the flow of water is proper. But there was no provision to flush out the pipe line choked with mud material to clean its inside.

As explained above, the water flows continuously inside the skid & post pipe for protecting the pipe from high temperature. To maintain a uniform water flow, the inside passage needs proper cleaning. So Skid & Post Pipes need to be flushed at regular interval. There was no flushing arrangement to flush out the skid & post pipes. As a result, mud material gets deposited inside the skid & post pipe narrowing the path. Therefore, sufficient water cannot flow inside the skid & post
pipe. So steam formation happens due to high temperature (i.e. 13300 cg). The

formation of steam inside the pipe cannot be controlled, due to lack of provision of mechanical device or flushing line to release steam quickly. This led to bursting of skid & post pipe of approximately 12 times / annum, which have been a big safety hazard as well as breakdown of Plant and consequent disruption of production. It needed immediate repairing for smooth running of Furnace. Changing of skid & post pipes require shutdown of Furnace. Cooling of Furnace requires 2 days, 3 days for repairing jobs and 2 days for heating of Furnace. This was causing production loss of Rs 1 core approximately per annum.

OBJECT OF INVENTION

The objective of the invention has been to overcome the problem of flushing out the mud material and steam formation inside the Skid and Post Pipes and prevent consequent bursting of Skid and Post Pipes causing imminent safety hazard as well as major breakdown of the plant and huge disruption in production.

Therefore such as herein described, there is provided an arrangement or cooling of skids and posts pipes in HSM Reheating Furnace done through closed loop soft water circuit. Mud material gradually deposited causes choking of Skid and Post pipes. Excessive choking leads to formation of steam causing bursting of pipes and also obstructs continuous proper flow of water to protect Skid and Post Pipes from high temperature of 13300 cg. Suitable flushing arrangement using Audco valves

incorporated in outlet line of cooling circuit for regular flushing of pipes to flush out mud material, avoid steam formation and consequent bursting of pipes as well as major plant breakdown..

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

Fig. 1(a) illustrates the re-heating furnace flushing pipe-line before implementation of valve;
Fig. 1(b) illustrates the pictorial representation of the re-heating furnace skid post flushing pipe-line before implementation of valve;
Fig. 1(c) illustrates the pictorial representation of the return pipe-line before implementation of valve;
Fig. 1(d) illustrates the pictorial representation of the skid and post leakage before implementation of valve;
Fig. 2(a) illustrates the pictorial representation of the re-heating furnace skid post flushing pipe-line after installation of valve in accordance with the present invention; Fig. 2(b) illustrates the pictorial representation of the flushing pipe-line, audco valve and return pipeline after installation of valve in accordance with the present invention;
Fig. 2(c) illustrates the pictorial representation of the flushing pipe-line with audco valve in accordance with the present invention;

DETAILED DESCRIPTION

Herein disclosed is the provision of the flushing Pipe line along with Audco valve at return line of both Re-heating Furnace, for saving the Skid and Post connecting pipe line from damages.

After intensive and extensive brain storming, assessing in-house facilities, analyzing alternate solutions, the team suggested an innovative idea of adding one meter length 50 mm diameter pipe with Audco valve at outlet lines of every bunch of Skid & Posts for flushing to release the sediments and steam.

This innovative idea implemented by the team with available resources, without making any stoppage of production process. Also flushing could be done while the Mill is in operation without taking the Furnace down. Periodical flushing with the help of Audco valve releases mud material and water flow has become reliable, preventing steam generation inside Skid & Posts.36 numbers of Audco valves were retrieved from the shop and made ready after fixing the flanges and pipes in the workshop. Trial implementation was done in Furnace #5 & Furnace #6 on planned shutdown after tapping holes in the outlet line of each group of Skid & Post system and flushing done periodically. After implementation, it has been observed that the cooling system is working very efficiently and leakage of Skid & Post pipes completely eliminated.

The implementation of the above creative idea has eliminated the major safety hazard of pipe bursting. The implementation of this highly innovative and creative idea has saved huge production loss to the tune of approximately Rupees One Crore to the Organization. This creative idea implementation has significantly enhanced employee morale and motivation and above all their safety.

Usefulness of the invention:

• Significant reduction in down time of Furnace has resulted in improved productivity due to elimination of the leakage in Skid & Post pipes.
• It has increased the efficiency of Furnaces, resulting in production of the best

Quality HR Coil, ensuring Customers’ delight.

• Power required for providing temporary illumination during cleaning and breakdown eliminated saving of huge energy consumption.
• The implementation of this creative and innovative idea has saved cumulative financial loss to the tune of approximately Rs.13, 28, 02,000/-.
• Earlier the flushing was done manually in a highly unsafe and hazardous condition. Now it has become convenient to flush out safely with the use and help of Audco valve.
• Working environment significantly improved due to arrest of water leakage from Skid & Post pipes as well as the disturbance caused to temperature of inside the Furnaces.

• Maintenance personnel greatly relieved who would have been otherwise engaged for attending to the frequent breakdowns. This has enhanced the morale of the employees, confidence and their satisfaction.
• A clean cellar floor without any water accumulation and slippery surface has ensured the safety of the employees after implementation of this creative idea.
• Drastic reduction in cost of Skid & Post pipes consumption and repairing.

• Elimination of waste of precious man-hours in attending to breakdown jobs.

Industrial Applicability: This creative and innovative idea is of immense utility and applicability to industries extensively using pipe lines for transportation of material like Oil, Natural Gas, Water transportation Sectors etc.

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 by way of examples and description and is not intended to be exhaustive or to limit the invention to the particular embodiments and applications disclosed. 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.