Pumps For Steel Plant
Water in large quantities is one of the most important in put to the process of steel making and has a large pumping cost associated with it. The number of working pumps and their running speeds and the number of stages to be employed is decided to achieve Specific Speed for highest possible efficiency.
The iron and steel industry in India is among the most important industries within the country. Steel sector in India has traversed a fascinating journey from a mere 1 MT at the time of independence to 120 MT in the last (2021-22) financial year, India surpassed Japan as the second top steel producer in January 2019. China represents 56.7% of world’s crude steel production, while Europe share is only 15.6%. India is the largest producer of sponge iron in the world with the coal-based route accounting for 90% of total sponge iron production in the country.
The Indian steel industry was de-licensed and de-controlled in 1991 and 1992 respectively. The new Steel Policy of 2017 enshrines the long term vision of the Government to give impetus to the steel sector. It seeks to enhance domestic steel consumption and ensure high quality steel production and create a technologically advanced and globally competitive steel industry. The policy projects crude steel capacity of 300 million tonnes (MT), production of 255 MT and seeks to increase per capita steel consumption to the level of 160 Kgs by 2030 from existing level of around 60 Kg and major segments of consumptions are infrastructure, automobiles and housing sectors. The policy also envisages to domestically meet the entire demand of high grade automotive steel, electrical steel, special steels and alloys for strategic applications and increase domestic availability of washed coking coal so as to reduce import dependence on coking coal from about 85% to around 65% by 2030-31.
The outlook for coming years is for a steady growth, in demand and production. Due to environmental concerns and lack of cost competitiveness, advanced countries are slowing down their production and expansion plans. But the rapid and sustained economic growth in developing Countries has propelled infrastructure development and demand for steel. Thus there is a gap between demand and supply and hence the prices are constantly at higher level. This is attracting expansion plans of many steel producers and in various states of India. Generally, availability of raw materials, availability of land, labour and power, abundant water supply and nearness to port facilities and favorable Govt. policies are some of the factors that attract the investments in steel segment.
Pumps for Steel Plants
Pumps required in Steel mills are basically for moving water, to meet requirements of various processes. Generally large amount of water is required for cooling purposes. A typical process flow chart for steel making is shown in Fig. 1 This is without a power plant of its own
Typical Pumps associated with blast furnace of 3.5 M. T. capacity can be listed as given below. These charts also give the total water quantities and heads associated with these processes. The number of pumps to be employed is governed by the availability of most efficient models at those duties and the requirement of stand-by pumps.
If we have a look at the Sinter plant, there are again activities involved and there are pumps associated with it. The Chart No.2 also gives total water quantities and heads associated with these pumps.
From Blast Furnace the product goes to Ladle 1 and Ladle 2 for Steel making. The Ladle No.1 is used for continuous billet casting. The pumps associated with LD1 and the water quantities and the heads associated are given in Chart No.3.
The Ladle No.2 is used as a slab caster. The pumps associated with LD2 and the water quantities and the heads associated are given in Chart No.4
From Ladle No.1 and Ladle No.2 the crude steel moves to further mills like Wire Mill, Merchant Mill and Cold Rolling Mill and Hot Strip Mills for making finished products. The pumps associated with Merchant Mill, Hot Strip Mill and Cold Rolling Mills along with total water quantities and heads involved are given in Charts Nos. 5, 6 and 7 respectively.
Chart No.5
Merchant Mills.
Chart No.6
Hot Strip Mill
Chart No.7
Cold Rolling Mill.
Chart No. 1 - Blast Furnace Pumps
| Sub Processes Involved | Application | Q- (m³/hr) | H- (mtr) | |
|---|---|---|---|---|
| A) Iron Making Process | Blast furnace | High pr. Indus. water | 2040 | 170 |
| Low pr. Indus. water | 6580 | 62 | ||
| Burden spray pump | 480 | 45 | ||
| Stave circulation pump | 5040 | 60 | ||
| Diesel pump for emergency | 1890 | 30 | ||
| Stave circulation pump | 630 | 28 | ||
| Hot well pump | 4800 | 20 | ||
| Drainage pit sump pump | 60 | 12 | ||
| Drainage pit sump pump for TLC | 96 | 9 | ||
| Recirculation water | 5 | 30 | ||
| Granulation supply pump | 6800 | 40 | ||
| Slurry pump | 10400 | 35 | ||
| Hot water pumps | 4800 | 45 | ||
| Condensation pump | 5600 | 35 | ||
| Clarifier pump | 200 | 8 | ||
| Sump pump | 400 | 20 | ||
| Booster pump | 120 | 25 | ||
| Slag quenching pump | 2160 | 45 | ||
| Sump pump | 60 | 20 | ||
| Waste Heat circulation Pump | 600 | 65 | ||
| Make up pump | 24 | 35 | ||
| Scrubber supply pump | 2100 | 100 | ||
| Scrubber recycle pump | 1125 | 90 | ||
| Gas cleaning sump pump | 60 | 12 |
Mechanical Seal Replacement Horizontal Split Case Pumps
Mechanical Seal Replacement Vertical Direct Mounted Pumps
If the Steel Mill has its own thermal power plant the pumps required for it will get added to the list of pumps required for steel mills. But this article does not consider this.
Considerations in pump selection
1) Lowest Life Cycle Cost (LLC) is the most important consideration for pump selection for any process these days
a) Highest possible efficiency of pump at the operating point is one aspect of LLC. Water in large quantities is one of the most important in put to the process of steel making and has a large pumping cost associated with it. Because of highest possible efficiency the energy consumption is less and it helps in keeping the costs of steel production down. The number of working pumps and their running speeds and the number of stages to be employed is decided to achieve Specific Speed for highest possible efficiency
b) Maintenance friendly features like externally removable, bearings and seals. Stiffer stainless steel shaft, positive locked and keyed impeller fixing, higher bearing life serrated wear rings, spacer coupling use of throttle bush, modular component design for optimum stocking of spare parts and double volute casings when radial loads dictate is another important aspect of LLC. These are shown in Fig. 2, 3, 4, 5 and 6
Basically the reliability of pumps which is very important for a continuous process of Steel production without any disruption is enhanced by these design features. More over the down time is considerably reduced. Both Maintenance and Down time have costs associated with it and in addition Down time is directly related to colossal loss of production.
2) When large vertical pumps are used for raw water application and when water is transferred from source over a longer distance in cross country pipeline, considerations of sump model studies as well as sump flow studies by CFD technique and surge analysis and surge protection also become important.
3) Remote monitoring and remote operation of the pumps without manual attendance is becoming a necessity these days, to save on manpower requirements and to keep the costs down. So pumps are required to have features, which are amenable to remote monitoring.
4) The atmosphere in the Blast Furnace areas, or in the areas of various mills is always hot and humid. The water is generally laden with particles. So due consideration is given to these facts while selecting the materials of construction as well as while sizing the electricals of the pumping equipment.
5) For ease of maintenance, for saving space, for overcoming NPSH problems, generally Horizontal Split Casing pumps, Split Casing pumps in Vertical execution, Vertical Turbine Pumps, Vertical mixed flow pumps, Multi Stage pumps in high pressure services, Submersible Solids handling pumps, Sump Pumps are preferred.
Mechanical Seal Replacement Vertical Turbine Pumps
LLC Horizontal Split Case Pump
Chart No. 2 - Sintering Plant Pumps
| Sub Processes Involved | Application | Q- (m³/hr) | H- (mtr) | |
|---|---|---|---|---|
| Iron Making | Sinter Plant | Process water supply pump | 1500 | 90 |
| Hot water pumps | 600 | 400 | ||
| Hot Water process pump | 240 | 90 | ||
| Motorized fire pumps | 546 | 90 | ||
| Sump pump | 20 | 10 | ||
| Jockey pump | 20 | 90 | ||
| Circular | 280 | 20 |
LLC Horizontal Split Case Pump In vertical Execution
LLC Vertical Turbine Pumps
Chart No. 3 Laddle One
| Sub Processes Involved | Application | Q- (m³/hr) | H- (mtr) | |
|---|---|---|---|---|
| Steel Making Process | LDI | Cooling water pump | 6600 | 50 |
| Secondary vessel pump | 6400 | 85 | ||
| IWC pump | 3240 | 95 | ||
| I W C pump | 2040 | 20 | ||
| Secondary cooling pump | 1360 | 20 | ||
| Filter pump | 80 | 30 | ||
| Filter pump | 1000 | 26 | ||
| Filter pump | 432 | 20 | ||
| Scale pit pumps | 2800 | 50 | ||
| Misc Utility pumps | 800–1200 | 35–40 |
Solids handling Sump Pumps
Submersible solids handling Pumps
Chart No. 4 - Laddle Two Sub Process - Steel Making
| Sub Processes Involved | Application | Q- (m³/hr) | H- (mtr) | |
|---|---|---|---|---|
| Steel Making Process | Blast furnace | STWTP/Vessel | 30 | 70 |
| GSWP/ VESSEL #1 & 2120 | 360 | 75 | ||
| GSWP/ VESSEL #3 | 240 | 92 | ||
| RH – DC WP | 1650 | 40 | ||
| RH – FILTER | 116 | 18 | ||
| BWTP/B/W | 100 | 25 | ||
| DCWP/VESSEL | 1240 | 90 | ||
| ICWP#1&2/ VESSEL | 800 | 50 | ||
| ICWP#3&4/ VESSEL | 4800 | 40 | ||
| SUMP PUMP/ RCPH | 20 | 20 | ||
| MOULD COOLING Pumps | 720 | 78 | ||
| Machine Cooling Pumps | 1410 | 78 | ||
| Back Wash at PCPH | 32 | 18 | ||
| Filter Plant at Slab Caster | 498 | 18 | ||
| Quencher Feed pump | 927 | 60 | ||
| Air washer Pump Filter no | 40 | 25 | ||
| Make up water pump | 28 | 25 | ||
| MOULD COOLING pumps | 1500 | 35 | ||
| Circulation water pumps | 1380 | 35 |
Chart No. 5 - Merchant Mills
| Sub Processes Involved | Application | Q- (m³/hr) | H- (mtr) |
|---|---|---|---|
| Merchant Mills | TMT Pump | 1280 | 120 |
| Hot Well Pump | 1100 | 15 | |
| Scale pit pump | 1666 | 45 |
Chart No. 6 - Hot Strip Mill
| Sub Processes Involved | Application | Q- (m³/hr) | H- (mtr) | |
|---|---|---|---|---|
| Steel Rolling Processes | Hot Strip Mill | Laminar Cooling pumps | 1005 | 55 |
| DCW | 1275 | 55 | ||
| ICW Pump #1 | 405 | 55 | ||
| ICW Pump #2 | 405 | 55 | ||
| ICW Pump #3 | 540 | 55 | ||
| Stream Filtration | 85 | 35 | ||
| Diesel Eng. Operated | 425 | 55 | ||
| 160 bar Descaling Pump | 2790 | 160 | ||
| 100 bar Descaling Pump | 930 | 100 | ||
| Amiad Filter 160 bar | 670 | 160 | ||
| Amiad Filter 100 bar | 335 | 100 | ||
| Hydac Filter 160 bar | 430 | 160 | ||
| Hydac Filter 160 bar | 215 | 100 | ||
| Roll cooling pump | 575 | 55 | ||
| Scale pit pump no 1 | 2400 | 60 | ||
| Fresh water pump | 70 | 20 | ||
| Scale pit pump no 2 | 2400 | 60 | ||
| Fresh water pump | 70 | 20 | ||
| Settling tank pump | 1350 | 60 |
Chart No. 7 – Cold Rolling Mill
| Sub Processes Involved | Application | Q- (m³/hr) | H- (mtr) |
|---|---|---|---|
| Cold Rolling Mill | Alkaline Soln pump | 3 | 17.5 |
| Alkaline Soln pump | 20 | 52.5 | |
| Thiourea solution pump | 6 | 30 | |
| Waste water pump | 18 | 30 | |
| Alkaline Slurry pump | 3 | 17.5 | |
| Alkaline Soln pump | 20 | 52.5 | |
| Alkaline Soln pump | 500 | 45 | |
| Alkaline Soln pump | 6 | 20 | |
| Alkaline Soln pump | 680 | 30 | |
| Alkaline Soln pump | 100 | 35 | |
| Alkaline Soln pump | 160 | 35 | |
| Alkaline Soln pump | 20 | 30 | |
| Thiourea solution pump | 10 | 30 | |
| DM water pumps | 1808 | 50 | |
| DM water pumps | 410 | 50 |
Conclusion:
Except for few pumps like slurry pumps descaling pumps, amide filter pumps or hydra pumps which are sometimes imported, most of the pumps required by Steel Mills are made by pump manufactures in India
Author Mr. Ravindra G Padalkar, a mechanical engineering graduate from the College of Engineering, Pune, a wide experience in design and development, factory management and turnkey projects in the field of centrifugal pumps and pumping systems. made career in this field with more than 40 years of experience. Thorough knowledge and varied experience of the subject won many laurels like the national award for indigenous development of 200 KW canned motor pumps. suggestion to reduce the number of pumping stations from 7 to 5 using siphon action, resulting in the saving of 15 MW installed power capacity. a certified energy auditor of Govt. of India and taken steps in energy conservation in many industries. notable contributions are the largest pumping system in India for SardarSarovar Narmada Nigam Ltd., sodium pumps for Fast Breeder Nuclear Reactor for the first time in India, development of a pump for critical application for BARC to simulate various conditions in the reactor used to collect the experimental data, etc.