Claims:CLAIMS:

1. A lubricating unit for real time lubricating the worm reducers of cooling tower fans (CTF’s) for continuous casting machine comprising of:
a closed tank/reservoir with a detachable lid, erected on a raised platform supported with structural to give a positive pressure gradient of flow;
a pipeline connected from the bottom opening of the said tank to the gearbox configured for smooth flow of oil;
a shut-off valve placed upstream over the said pipeline to allow/block/regulate flow of lubricating oil to the gearbox to eliminate unwanted oil spillage/wastage; wherein
the said pipe-line includes a dip-stick inserted into it to realize the level of lubricating oil in the gearbox in order to regulate the flow of oil from the tank when top up of oil is required.

2. A lubricating unit for real time lubricating as claimed in claim 1, wherein the tank/reservoir includes a dipstick for identifying the requirement of replenishment of fresh oil in the tank/reservoir.

3. A lubricating unit for real time lubricating as claimed in claim 1, wherein the CTF’s are configured that the mould inlet temperature does not exceed the threshold limit of 42oC.

4. A lubricating unit for real time lubricating as claimed in claim 1, wherein the said closed tank/reservoir with a detachable lid is fabricated from larger diameter pipes.

5. A lubricating unit for real time lubricating as claimed in claim 1, further comprises a dipstick arrangement connected for the requirement of replenishment of fresh oil in the tank/reservoir.

Dated: this 30th day of September, 2016.
(N. K. Gupta)
Patent Agent,
Of NICHE,
For SAIL.
To,
The Controller of Patents,
The Patent Office, Kolkata.
, Description:

FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
COMPLETE SPECIFICATION
(Section 10 and rule 13)

TITLE

LUBRICATING UNIT FOR REAL TIME LUBRICATING THE WORM REDUCERS OF COOLING TOWER FANS (CTFS)

APPLICANT
STEEL AUTHORITY OF INDIA LIMITED,
A GOVT. OF INDIA ENTERPRISE,
ROURKELA STEEL PLANT,
ROURKELA – 769011,
ORISSA, INDIA

The following specification particularly describes the nature of the
invention and the manner in which it is to be performed
LUBRICATING UNIT FOR REAL TIME LUBRICATING THE WORM REDUCERS OF COOLING TOWER FANS (CTFS)

FIELD OF INVENTION:
The invention relates to apparatus for real time lubricating the worm reducers of Cooling Tower Fans (CTFs). More particularly, the present invention relates to a lubrication unit for moving gears / bearings suitable for CTF’s of continuous casting machines.

BACKGROUND ART:
No specific equipment or device or system known or prevalent. Normally, large cooling towers incorporate oil fill in their standard design but on smaller gearboxes () oil fill and gauge lines are offered as optional equipment and available if the may be, they are situated too close to the running fans. .A person has to take oil in a can and bend his knees to a crouching position to put oil in the gearbox.

The present method of manual lubrication was highly inefficient. Instances of a workman undertaking this arduous job for every CTF (total 06 in number) twice or thrice a week were both time and labour intensive. Moreover, there occurred oil spillage/wastage due to this inept method and the gearboxes would not be sufficiently lubricated thus, there were frequent occurrences of starved gearbox failure.
The invention has been installed and commissioned in all Cooling Tower Fans (CTFs) of Continuous Casting Machine-I (CCM-I) Shop of Steel Melting Shop-I(SMS-I) of Rourkela Steel Plant, SAIL.
There are 2nos. of 66 tons LD convertors at SMS-I, namely Convertor #P & #Q, produce 0.42MT steel annually. There is a single strand slab caster and a turret for handling the ladles and providing steel on continuous basis. They can rotate 360o and can lift a 70 T ladles.
The slab caster has a water cooled copper mould, which gives the required dimensions of the slabs produced. The strand produced is further cooled by water sprayed through specially designed nozzles and simultaneously pulled out by drive rolls and straightened. The continuous long strand is cut at suitable lengths to form slabs and is cut by using transverse torch cutting machine, which moves along with the strand and cuts slabs using oxygen and acetylene.

Average heat size: 60-70 tons
No. of strand / machine: 1
Casting size: 210 mm thickness
Width: 800 - 1275 mm
Length: 6000 - 8000 mm

Caster of SMS-I was commissioned in 1996 with a production capacity of 0.305 MT steel. Subsequently, production and quality demand in SMS-I increased, with quality heats like CRNO, SAILMA, IS3589 etc taking up 70% of planned production with longer heat sequences of 8 and more. But upgrading the caster from an original envisaged plan of 2 heats to 8 or more heats with quality heats was quite challenging. Notwithstanding due modification in secondary cooling and logistics, it was not possible to go beyond 5 heat sequence in summer months because of the mould inlet temperature/ primary cooling circuit breaching its threshold limit of 42oC.

The copper mould of CCM-I, SMS-I is a curve mould design with non- variable (constant) water flow; altering water flow for increased heat flux removal from liquid hot steel would be at variance with its design philosophy. There were two plate type heat exchangers (PHEs) for mould cooling circuit in which the cooling water was circulated by a vertical turbine of 800m3/hr rated capacity. The cooling tower meant for cooling the auxiliary water has 3 cells of which 2 remain in operation at a time for maintainability issues.

Longer sequences required all 3 cooling tower fan (CTF) cells to run simultaneously; the CTFs gearbox were of worm reduction type with splash lubrication but because of inadequate lubrication – design constraint- brass worm gears would wear out quickly and the CTFs were always under mechanical m/c.

TABLE: 1 – Instances of CTF gearbox failure due to improper lubrication over the years:

YEAR 2011-12 2012-13 2013-14 2014-15 2015-16
NO.OF CTF G/BOX FAILURE (LUBRICATION ISSUES) 3 3 1 0 0

As it was difficult to manually take oil in cans up above the CTs for periodical top-ups, an oil tank of required capacity was fabricated at the site and pipeline was drawn from it to the g/box of the CT fans as such oil could be top-up at regular intervals by simply operating the shut-off valve below the tank. With this unique piece of work, lubrication of the geared reducers can be done easily and safely. This has eliminated the breakdowns of the cooling towers completely, resulting in higher sequence sizes through effective control of the mould cooling water inlet temperature.

OBJECT OF THE INVENTION:
The present invention overcomes the shortcomings associated with the background art and achieves other advantages not realized by the background art.
An object of the present invention is to provide a lubrication unit for CTF’s in which the aforementioned problems of the background art are solved.The basic objective of the invention is to provide a more competent and effective method of lubricating the worm reducers of the CTFs to increase its availability and reliability of operation.
A further objective is to utilize the increased reliability of the CTFs to successfully control the mould inlet temperature; to ensure that the mould inlet temperature does not exceed the threshold limit of 42oC thus enabling higher heat sequences in caster without risking the equipment thereof.
The mentioned development has been done in-house with minimum investment to provide an easy to operate/maintain system which saved on both time and labor resource. Increase in caster yield and Total Tundish Management of over 8 ladles has been achieved and costly downtime due to repair/replacement of CTF gearbox has been done away with.
Therefore such as herein described there is disclosed a lubricating unit for real time lubricating the worm reducers of cooling tower fans (CTF’s) comprising of:a closed tank/reservoir with a detachable lid, erected on a raised platform supported with structural to give a positive pressure gradient of flow,a pipeline connected from the bottom opening of the said tank to the gearbox configured for smooth flow of oil;a shut-off valve placed upstream over the said pipeline to allow/block/regulate flow of lubricating oil to the gearbox to eliminate unwanted oil spillage/wastage; wherein the said pipe-line includes a dip-stick inserted into it to realize the level of lubricating oil in the gearbox in order to regulate the flow of oil from the tank when top up of oil is required.
Cost-benefit analysis shows annual recurring savings of Rs. 5-10 lakhs on account of elimination of oil wastage and gearbox replacement and Rs 116000/day (Rs1000(min NSR)*116(extra tons of value added product casted)) to the bottom-line of the company.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig. 1 illustrates instances of CTF gearbox failure due to improper lubrication over the years;
Fig. 2 illustrates oil consumption for CTFs gearboxes over the years in accordance with the present invention;
Fig. 3 illustrates average heat sequence (no of steel ladles casted) over the years in accordance with the present invention;
Fig.4 illustrates real time lubrication of CTF gear reducers (AS FABRICATED )in accordance with the present invention;
Fig. 5 illustrates real time online lubrication of CTF gear reducers (PICTORIAL VIEW) in accordance with the present invention;

DETAILS OF THE INVENTION:
The present invention is directed to achieve a modified standard practice of lubricating the worm gear reducers of CTFs wherein the manual exercise of lubrication has been done with. The lubricating unit hereby claimed to have been developed for lubricating the gears for their optimum working and configured to increase its availability and reliability for effectively controlling the mould inlet temperature of the caster- detrimental factor in deciding the length of heat sequence in the caster. The invention can be replicated to lubricate all possible configurations of CTFs.
Referring to Fig. 4 and 5, the real time lubrication of geared reducers of CTFs was achieved by assembling the following apparatus and propping them up with strong structural framework to achieve a sturdy mechanism of seamless lubrication namely:
a) tank/reservoir; b) shut-off valve; c) connecting pipeline; d) dip-stick; and e) connector fittings.

A closed tank/reservoir with a detachable lid was fabricated from larger diameter pipes. The tank was erected on a raised platform supported with structural to give a positive pressure gradient of flow. A bottom opening was created for laying the pipeline from the tank to the gearbox; a shut-off valve was placed upstream to allow/block/regulate flow of lubricating oil to the gearbox to eliminate unwanted oil spillage/wastage. The pipe-line was so laid out to have a dipstick inserted into it to realize the level of lubricating oil in the gearbox in order to know as and when top up of oil is required. A similar dipstick identified the requirement of replenishment of fresh oil in the tank/reservoir.

As the previous (prior art) method of lubrication was highly laborious, unsafe in nature, a noble safer and efficient means of achieving the said objective is herein claimed where the concerned work-personnel has to remove the dipstick then check the level of lubricating oil in the gear-box and top-off if required without ever going too close to the equipment nor call for any operation shutdown of the said equipment for the same. No longer is it required to employ the services of extra work personnel for hauling up the large oil cans, setting up the safety ladder and other platform and issue shutdown of the equipment.

In an example, the increased reliability of the CTFs to successfully control the mould inlet temperature of CCM’s and is ensured that the mould inlet temperature does not exceed the threshold limit of 42oC thus enabling higher heat sequences in caster without risking the equipment thereof.Better lubrication has increased the availability and reliability of the said equipment bolstering the pace of production- quality products – in the said production unit (CCM-I, SMS-I). As the more efficient counter-flow CTFs bring down the effective temperature of fresh water being pumped into the heat exchangers for cooling down the circulating soft water which extracts the heat from hot metal at the mould to cool down to solidify into pre-determined shapes, production rate - caster throughput is greatly enhanced.

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.