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Actuator Sensor-Interface: Intelligent Cabling for a Machine

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Automation involves exchange of data from across the field to a central control unit. In the conventional system, the entire machine is surrounded by cables which increase the hassles and time involved in maintenance, commissioning and diagnostics. Field bus technology involves the use of a common protocol for data exchange in a serial way between the central control unit and the field devices thereby eliminating the need of traditional hardwiring. Decentralized I/O modules are kept on the field and the sensors and actuators are wired to these. These remote I/O modules communicate to the PLC by bus-systems or communication protocols like PROFIBUS/ MODBUS/ AS-i etc.In the yester years, there was no scarcity of materials like copper, iron etc. Supplies of the materials were more than the demand. Labour was also available in abundance. However, over the years, the labour cost and the material cost has been increasing which in turn means an increase in the production cost or the product cost. Additionally there is an ever-increasing pressure to reduce the prices of the products due to the increasing competition. Hence the manufacturers are on a constant look-out for reducing the cost of production and thereby to reduce the price of their products. Automation is one of the ways to achieve this.Centralized SystemThe introduction of automation was a revolution in itself. Automation involves exchange of data from across the field to a central control unit. The data exchanged can be of various types ranging from system data, process parameters, analogue data or binary data. Also the nature of exchange of these data varies and can be cyclic or acyclic. Taking an example of a conventionally wired conveyor system:Along the conveyor line, there are sensors like limit switches, proximity sensors etc. which give input to the PLC about the materials being conveyed. Based on the requirement, the PLC gives output to the contactors to switch off or switch on the conveyor. The switching action can also be done locally by means of actuators like push buttons, E-stop button etc. Conventionally, each of the actuator/ sensor along the conveyor was connected by hard-wire to the marshalling tier. From the marshalling tier, the inputs and outputs are connected to the PLC by means of a multi-core cable. This was referred to as "centralized control" where in all the data from the entire plant would be wired to the PLC located at certain location in the plant. The following drawbacks were encountered:These drawbacks lead to the development of the decentralized control systems – which means distributing intelligence in the field. To make communication faster and the automation hardware simpler, field bus concepts came into existence. Field bus technology involves the use of a common protocol for data exchange in a serial way between the central control unit and the field devices thereby eliminating the need of traditional hardwiring. In this system, only the hardware or the hardware as well as the software can be decentralized. Decentralized I/O modules are kept on the field and the sensors and actuators are wired to these. These remote I/O modules communicate to the PLC by bus-systems or communication protocols like PROFIBUS/ MODBUS/ AS-i etc.Decentralized System (System using AS-i)

Actuator sensor interface is a bus system designed as an interface (connection media) for all simple binary ON/ OFF field devices (pushbuttons, limit switches, proximity sensors, valves, contactor coils) to the higher level of automation. In this communication bus system or protocol, the hardware is only decentralized. In this system, the basic components at the field level are AS-i master, AS-i slaves (or I/O modules) and the AS-i power supply. AS-i, slave modules (I/O Module selected based on the number and type of inputs and outputs) are mounted near the sensor cluster. A single AS-i cable runs through the slaves, to the AS-i master and power supply. The AS-i master in turn is connected to the PLC. Thus, AS-I replaces the cable tree at the lowest level of automation in the industry where conventional hardwiring/ field bus tend to be too complicated, too slow or too expensive. The result is an immense reduction in wiring – "one instead of a thousand cables".What is AS-i??AS-i is an open and manufacturer-independent bus system transmitting process- and machine-level digital/ analog signals and safety-oriented signals to the PLC. It’s a universal interface between actuators and sensors on the field level to the superior control level of PROFIBUS/ Ethernet/ others. AS-I is basically a Master-Slave system. Master-Slave refers to the method the field-bus uses to transfer information. The master is responsible for the operations of the bus system. One AS-I master can have a maximum of 62 slaves of 4I/4O each (according to AS-I specification ver 3.0) over a length of 100m (expandable upto 600 m with repeaters and other accessories).AS-interface was conceived as a single master system with cyclic polling. This means that there is only one control module (master) in the AS-Interface network which polls the data of the other nodes (slaves) at precisely defined intervals. Up to four useable input bits and four useable output bits are exchanged between a slave and the master in any one cycle. AS-interface has been optimised for volumes of data that correspond precisely to the requirements of the lowest field levelThe basic components in an AS-i system consist of master, slaves, power supply and the AS-i cable.AS-i Master – It provides an interface between the slaves and the PLC. The AS-Interface master forms the connection to higher level controls. It independently organizes the data traffic on the AS-Interface line and is responsible for parameter settings, monitoring and diagnostic functions.AS-i Slaves – The AS-i slaves can either be AS-i enabled valves, push button stations, limit switches etc or can be AS-i enabled I/O cards on which the actuators and sensors are connected.AS-Interface slaves include the AS-i electronics. The I/O cards can either be IP20 (can be installed in a control cabinet) or IP67 modules (that are directly used in the field).AS-i Power Supply – This is a special 30V DC power supply which decouples the power and the data signal. The power supply units generate a controlled DC voltage of 24 or 30 V with a high degree of stability and low residual ripple. They supply the network’s electronics, i.e. the AS-i modules and the master as well as the connected sensors. AS-Interface power supply units generate a nominal voltage of 30 V DC.AS-i cable – The AS-i cable has to meet the specifications laid down in the AS-i standard specifications. The yellow, flat cable is characteristic for the AS-Interface. Data and power for the sensors are transferred along this cable. A second, black flat cable is used to supply the actuators with 24 V. Both of these cables use the piercing technology, specifically developed for AS-i. This allows every node to be simply snapped onto the two profiled cables at any location – also with the correct polarity. In case of the IP67 AS-i slaves, the wiring is done by "piercing technology". In this case, the geometry of the cable is such that polarity reversal is not possible and hence errors during installation are minimized. The trapezoidal profile with the profiled lug ensures a high degree of protection against polarity reversal (mechanical code). In case of IP20 modules, regular copper wires can be used. The IP20 modules have removable terminals which makes the wiring easy.Benefits of AS-i"One instead of a thousand cables"In the conventional system, the entire machine is surrounded by cables which increase the hassles in maintenance. By AS-i, maintenance is hassle-free.

  • Less wiring implies less cost – cabling, wiring, maintenance etc.
  • No wiring faults. Confusion of terminals excluded.

Short downtimes thanks to fast replacementThe IP67 modules enable quick installation. The slaves in an AS-i network hooks on to the cable without any trouble due to the piercing technology of the cables. Hot-replacement, ie., replacement of the modules without shutting down of the system is possible. Contact needles pierce through the cable insulation and make secure contact with the copper conductor. When the needles are pulled out again to remove a slave, the cable’s self-healing capability ensures that the holes close automatically, providing full insulation again (in the case of EPDM cables)Less commissioning and configuration timeThe slaves can be pre-addressed using the addressing tool. The master can be parameterized easily without putting it on-line.Less maintenance timeIn case of any failure, the diagnostics are fast. The replacements of the salves are easy due to the hot-replacement featureEasier diagnosticsDue to diagnostics available at various levels the down-time of the plant reduces. AS-i provides diagnostic information at the device level by means of LEDs. Diagnostic information are also available on the AS-i Master. It can also be configured to get diagnostic information on PLC/ SCADA/ HMI panels.ExpandabilityThe system is flexible and hence is expandable very easily with minimal downtime. A shut-down of the plant is not required for a long time due to the off-line configurability, hot-replacement etc.AS-i – as part of Totally Integrated AutomationThe AS-i association was founded in 1991 and since then, the specifications for AS-i has undergone continuous improvement. Presently, AS-i adheres to specification version 3.0.Some of the features of AS-i specification ver 3.0 are:

  • Binary I/O nodes supporting A/B addressing with 4 Inputs and 4 Outputs
  • Binary I/O nodes supporting A/B addressing with 8 Inputs and 8 Outputs
  • Integrated safety (AS-i safe)
  • Improved diagnostics

All AS-Interface products correspond to

  • Euro Norm EN 50295 and
  • World Standard IEC 62026-2

All certified AS-i products (recognisable by the AS-interface shadow logo and the corresponding test number) are fully compatible with each other independent of the manufacturer and are interchangeable.AS-i forms part of the TIA pyramid (Totally Integrated Automation – the hierarchy of the communication protocols available.) AS-i is at the lowest control level, where it is used to interlink process-related devices like sensors, actuators etc, with one-another and to the next higher automation level.The next level is either the field-bus level like Profibus/ Modbus etc followed by the operating control level like Industrial Ethernet.Being the lowest level of automation, AS-i is not designed to handle large volumes of data. The structure and length of the data frame is fixed. Up to four useable input bits and four useable output bits are exchanged between a slave and the master in any one cycle. At this level, however, there are a high number of connected devices all with the requirement for real time/deterministic capability.From AS-i, gateways to EtherNet/IPTM, PROFINET, Modbus/TCP and others are available. With the new and continuously improving capabilities, AS-interface is the ideal partner network for any of the currently available Ethernet based industrial protocols. The future of the communication networks are seen as a 2-level hierarchy comprising of Field bus like AS-i and then the Ethernet based protocols.The author is Mangala R. Nair, Control Products Department, Siemens Ltd

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Economy & Market

Impactful Branding

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Advertising or branding is never about driving sales. It’s about creating brand awareness and recall. It’s about conveying the core values of your brand to your consumers. In this context, why is branding important for cement companies? As far as the customers are concerned cement is simply cement. It is precisely for this reason that branding, marketing and advertising of cement becomes crucial. Since the customer is unable to differentiate between the shades of grey, the onus of creating this awareness is carried by the brands. That explains the heavy marketing budgets, celebrity-centric commercials, emotion-invoking taglines and campaigns enunciating the many benefits of their offerings.
Marketing strategies of cement companies have undergone gradual transformation owing to the change in consumer behaviour. While TV commercials are high on humour and emotions to establish a fast connect with the customer, social media campaigns are focussed more on capturing the consumer’s attention in an over-crowded virtual world. Branding for cement companies has become a holistic growth strategy with quantifiable results. This has made brands opt for a mix package of traditional and new-age tools, such as social media. However, the hero of every marketing communication is the message, which encapsulates the unique selling points of the product. That after all is crux of the matter here.
While cement companies are effectively using marketing tools to reach out to the consumers, they need to strengthen the four Cs of the branding process – Consumer, Cost, Communication and Convenience. Putting up the right message, at the right time and at the right place for the right kind of customer demographic is of utmost importance in the long run. It is precisely for this reason that regional players are likely to have an upper hand as they rely on local language and cultural references to drive home the point. But modern marketing and branding domain is exponentially growing and it would be an interesting exercise to tabulate and analyse its impact on branding for cement.

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Concrete

Indian cement industry is well known for its energy and natural resource efficiency

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Dr Hitesh Sukhwal, Deputy General Manager – Environment, Udaipur Cement Works Limited (UCWL) takes us through the multifaceted efforts that the company has undertaken to keep emissions in check with the use of alternative sources of energy and carbon capture technology.

Tell us about the policies of your organisation for the betterment of the environment.
Caring for people is one of the core values of our JK Lakshmi Cement Limited. We strongly believe that we all together can make a difference. In all our units, we have taken measures to reduce carbon footprint, emissions and minimise the use of natural resources. Climate change and sustainable development are major global concerns. As a responsible corporate, we are committed with and doing consistent effort small or big to preserve and enrich the environment in and around our area of operations.
As far as environmental policies are concerned, we are committed to comply with all applicable laws, standards and regulations of regulatory bodies pertaining to the environment. We are consistently making efforts to integrate the environmental concerns into the mainstream of the operations. We are giving thrust upon natural resource conservation like limestone, gypsum, water and energy. We are utilising different kinds of alternative fuels and raw materials. Awareness among the employees and local people on environmental concerns is an integral part of our company. We are adopting best environmental practices aligned with sustainable development goals.
Udaipur Cement Works Limited is a subsidiary of the JK Lakshmi Cement Limited. Since its inception, the company is committed towards boosting sustainability through adopting the latest art of technology designs, resource efficient equipment and various in-house innovations. We are giving thrust upon renewable and clean energy sources for our cement manufacturing. Solar Power and Waste Heat Recovery based power are our key ingredients for total power mix.

What impact does cement production have on the environment? Elaborate the major areas affected.
The major environmental concern areas during cement production are air emissions through point and nonpoint sources due to plant operation and emissions from mining operation, from material transport, carbon emissions through process, transit, noise pollution, vibration during mining, natural resource depletion, loss of biodiversity and change in landscape.
India is the second largest cement producer in the world. The Indian cement industry is well known for its energy and natural resource efficiency worldwide. The Indian cement industry is a frontrunner for implementing significant technology measures to ensure a greener future.
The cement industry is an energy intensive and significant contributor to climate change. Cement production contributes greenhouse gases directly and indirectly into the atmosphere through calcination and use of fossil fuels in an energy form. The industry believes in a circular economy by utilising alternative fuels for making cement. Cement companies are focusing on major areas of energy efficiency by adoption of technology measures, clinker substitution by alternative raw material for cement making, alternative fuels and green and clean energy resources. These all efforts are being done towards environment protection and sustainable future.
Nowadays, almost all cement units have a dry manufacturing process for cement production, only a few exceptions where wet manufacturing processes are in operation. In the dry manufacturing process, water is used only for the purpose of machinery cooling, which is recirculated in a closed loop, thus, no polluted water is generated during the dry manufacturing process.
We should also accept the fact that modern life is impossible without cement. However, through state-of-the-art technology and innovations, it is possible to mitigate all kinds of pollution without harm to the environment and human beings.

Tell us about the impact blended cement creates on the environment and emission rate.
Our country started cement production in 1914. However, it was introduced in the year 1904 at a small scale, earlier. Initially, the manufacturing of cement was only for Ordinary Portland Cement (OPC). In the 1980s, the production of blended cement was introduced by replacing fly ash and blast furnace slag. The production of blended cement increased in the growth period and crossed the 50 per cent in the year 2004.
The manufacturing of blended cement results in substantial savings in the thermal and electrical energy consumption as well as saving of natural resources. The overall consumption of raw materials, fossil fuel such as coal, efficient burning and state-of-the-art technology in cement plants have resulted in the gradual reduction of emission of carbon dioxide (CO2). Later, the production of blended cement was increased in manifolds.
If we think about the growth of blended cement in the past few decades, we can understand how much quantity of , (fly ash and slag) consumed and saved natural resources like limestone and fossil fuel, which were anyhow disposed of and harmed the environment. This is the reason it is called green cement. Reduction in the clinker to cement ratio has the second highest emission reduction potential i.e., 37 per cent. The low carbon roadmap for cement industries can be achieved from blended cement. Portland Pozzolana Cement (PPC), Portland Slag Cement (PSC) and Composite Cement are already approved by the National Agency BIS.
As far as kilogram CO2 per ton of cement emission concerns, Portland Slag Cement (PSC) has a larger potential, other than PPC, Composite Cement etc. for carbon emission reduction. BIS approved 60 per cent slag and 35 per cent clinker in composition of PSC. Thus, clinker per centage is quite less in PSC composition compared to other blended cement. The manufacturing of blended cement directly reduces thermal and process emissions, which contribute high in overall emissions from the cement industry, and this cannot be addressed through adoption of energy efficiency measures.
In the coming times, the cement industry must relook for other blended cement options to achieve a low carbon emissions road map. In near future, availability of fly ash and slag in terms of quality and quantity will be reduced due to various government schemes for low carbon initiatives viz. enhance renewable energy sources, waste to energy plants etc.
Further, it is required to increase awareness among consumers, like individual home builders or large infrastructure projects, to adopt greener alternatives viz. PPC and PSC for more sustainable
resource utilisation.

What are the decarbonising efforts taken by your organisation?
India is the world’s second largest cement producer. Rapid growth of big infrastructure, low-cost housing (Pradhan Mantri Awas Yojna), smart cities project and urbanisation will create cement demand in future. Being an energy intensive industry, we are also focusing upon alternative and renewable energy sources for long-term sustainable business growth for cement production.
Presently, our focus is to improve efficiency of zero carbon electricity generation technology such as waste heat recovery power through process optimisation and by adopting technological innovations in WHR power systems. We are also increasing our capacity for WHR based power and solar power in the near future. Right now, we are sourcing about 50 per cent of our power requirement from clean and renewable energy sources i.e., zero carbon electricity generation technology. Usage of alternative fuel during co-processing in the cement manufacturing process is a viable and sustainable option. In our unit, we are utilising alternative raw material and fuel for reducing carbon emissions. We are also looking forward to green logistics for our product transport in nearby areas.
By reducing clinker – cement ratio, increasing production of PPC and PSC cement, utilisation of alternative raw materials like synthetic gypsum/chemical gypsum, Jarosite generated from other process industries, we can reduce carbon emissions from cement manufacturing process. Further, we are looking forward to generating onsite fossil free electricity generation facilities by increasing the capacity of WHR based power and ground mounted solar energy plants.
We can say energy is the prime requirement of the cement industry and renewable energy is one of the major sources, which provides an opportunity to make a clean, safe and infinite source of power which is affordable for the cement industry.

What are the current programmes run by your organisation for re-building the environment and reducing pollution?
We are working in different ways for environmental aspects. As I said, we strongly believe that we all together can make a difference. We focus on every environmental aspect directly / indirectly related to our operation and surroundings.
If we talk about air pollution in operation, every section of the operational unit is well equipped with state-of-the-art technology-based air pollution control equipment (BagHouse and ESP) to mitigate the dust pollution beyond the compliance standard. We use high class standard PTFE glass fibre filter bags in our bag houses. UCWL has installed the DeNOx system (SNCR) for abatement of NOx pollution within norms. The company has installed a 6 MW capacity Waste Heat Recovery based power plant that utilises waste heat of kiln i.e., green and clean energy source. Also, installed a 14.6 MW capacity solar power system in the form of a renewable energy source.
All material transfer points are equipped with a dust extraction system. Material is stored under a covered shed to avoid secondary fugitive dust emission sources. Finished product is stored in silos. Water spraying system are mounted with material handling point. Road vacuum sweeping machine deployed for housekeeping of paved area.
In mining, have deployed wet drill machine for drilling bore holes. Controlled blasting is carried out with optimum charge using Air Decking Technique with wooden spacers and non-electric detonator (NONEL) for control of noise, fly rock, vibration, and dust emission. No secondary blasting is being done. The boulders are broken by hydraulic rock breaker. Moreover, instead of road transport, we installed Overland Belt Conveying system for crushed limestone transport from mine lease area to cement plant. Thus omit an insignificant amount of greenhouse gas emissions due to material transport, which is otherwise emitted from combustion of fossil fuel in the transport system. All point emission sources (stacks) are well equipped with online continuous emission monitoring system (OCEMS) for measuring parameters like PM, SO2 and NOx for 24×7. OCEMS data are interfaced with SPCB and CPCB servers.
The company has done considerable work upon water conservation and certified at 2.76 times water positive. We installed a digital water flow metre for each abstraction point and digital ground water level recorder for measuring ground water level 24×7. All digital metres and level recorders are monitored by an in-house designed IoT based dashboard. Through this live dashboard, we can assess the impact of rainwater harvesting (RWH) and ground water monitoring.
All points of domestic sewage are well connected with Sewage Treatment Plant (STP) and treated water is being utilised in industrial cooling purposes, green belt development and in dust suppression. Effluent Treatment Plant (ETP) installed for mine’s workshop. Treated water is reused in washing activity. The unit maintains Zero Liquid Discharge (ZLD).
Our unit has done extensive plantations of native and pollution tolerant species in industrial premises and mine lease areas. Moreover, we are not confined to our industrial boundary for plantation. We organised seedling distribution camps in our surrounding areas. We involve our stakeholders, too, for our plantation drive. UCWL has also extended its services under Corporate Social Responsibility for betterment of the environment in its surrounding. We conduct awareness programs for employees and stakeholders. We have banned Single Use Plastic (SUP) in our premises. In our industrial township, we have implemented a solid waste management system for our all households, guest house and bachelor hostel. A complete process of segregated waste (dry and wet) door to door collection systems is well established.

Tell us about the efforts taken by your organisation to better the environment in and around the manufacturing unit.
UCWL has invested capital in various environmental management and protection projects like installed DeNOx (SNCR) system, strengthening green belt development in and out of industrial premises, installed high class pollution control equipment, ground-mounted solar power plant etc.
The company has taken up various energy conservation projects like, installed VFD to reduce power consumption, improve efficiency of WHR power generation by installing additional economiser tubes and AI-based process optimisation systems. Further, we are going to increase WHR power generation capacity under our upcoming expansion project. UCWL promotes rainwater harvesting for augmentation of the ground water resource. Various scientifically based WHR structures are installed in plant premises and mine lease areas. About 80 per cent of present water requirement is being fulfilled by harvested rainwater sourced from Mine’s Pit. We are also looking forward towards green transport (CNG/LNG based), which will drastically reduce carbon footprint.
We are proud to say that JK Lakshmi Cement Limited has a strong leadership and vision for developing an eco-conscious and sustainable role model of our cement business. The company was a pioneer among cement industries of India, which had installed the DeNOx (SNCR) system in its cement plant.

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Concrete

NTPC selects Carbon Clean and Green Power for carbon capture facility

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Carbon Clean and Green Power International Pvt. Ltd has been chosen by NTPC Energy Technology Research Alliance (NETRA) to establish the carbon capture facility at NTPC Vindhyachal. This facility, which will use a modified tertiary amine to absorb CO2 from the power plant’s flue gas, is intended to capture 20 tonnes of CO2) per day. A catalytic hydrogenation method will eventually be used to mix the CO2 with hydrogen to create 10 tonnes of methanol each day. For NTPC, capturing CO2 from coal-fired power plant flue gas and turning it into methanol is a key area that has the potential to open up new business prospects and revenue streams.

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