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Across the world, silos are fumigated using phosphine gas, typically generated either through phosphine generators or a closed-loop fumigation system. The process demands careful timing and execution—especially when exposing aluminium phosphide (Selphos) tablets to release gas in line with prevailing atmospheric conditions. However, during my interactions with silo operators and authorities, including the Food Corporation of India (FCI), I observed a significant lack of uniformity. Practices vary widely in terms of phosphine concentration levels (ppm) and exposure durations, raising concerns about the overall effectiveness of fumigation. This inconsistency, I believe, calls for introspection and scientific validation. Drawing from the FAO Bulletin, the recommended concentration is 285 ppm for 15 days. In my view, extending this duration to 21 days could ensure that even weevil eggs progress to the larval stage and are fully exterminated. Anything less risks leaving behind surviving pests, which often leads to the mistaken belief that insects are developing immunity to phosphine. Grain storage is not just a technical operation—it is a high-stakes business where lapses can lead to massive losses. By adopting uniform best practices, maintaining the right fumigant concentration, and preventing cross-contamination, we can ensure 100% insect mortality and safeguard both food security and farmer value. It’s time the industry shifts from variable methods to a validated, standardized approach in silo fumigation.

Through my interactions on LinkedIn, during webinars, and at seminars, I have observed that condensation in silos remains an under-defined and insufficiently standardized issue. Despite its critical impact on grain quality, this challenge is often overlooked. In my field experience, I relied on a psychrometric chart along with a hygrometer equipped with wet-bulb and dry-bulb thermometers to understand and monitor condensation risks. Another key factor is the capacity of stationary vents and ventilators, which play a vital role in displacing stale air trapped in the silo headspace. To address this effectively, it is essential for silo operators to consult silo manufacturers while designing or upgrading ventilation systems, ensuring that exhaust capacity is properly defined and adequate for safe grain storage. I strongly urge silo operators and industry stakeholders to revisit this critical aspect of silo operations. Proactive measures to prevent condensation not only safeguard stored grains but also enhance operational efficiency and long-term sustainability.

The ambience since last week been vibrating for a weekend Rakhi festival and this week on the Independence day vibrancy. Rather putting up a blog on a serious matter I decided to share my admiration and addition for the Indian movies. Few movies did make long lasting impact on me. First one was Guide which taught me to be ready for sudden change in life and never give up on adverse ones. The second movie Saudagar which taught me professional lesson and eventually I choose to be a Technologist from an Engineer. The story line is Nutan the central character a widow married to Amitabh Bachchan knew the art of making jaggery from the sap of palm trees. This love triangle emphasized how an art or a technology fetches the high income for Amitabh Bachan. Same source of palm tree sap having same utensils for preparing the jiggery resulted in different taste that too by an effortless trick. Out of my 39 years of professional experience I am following the technological learnings with reasonable success rate and I am spreading these learnings to the fraternity at various platforms. I wish you all a nice weekend and best wishes for the Independence Day. Sabse Achcha Gud – Amitabh Bachchan – Saudagar – https://youtu.be/X7j4erTS0AA?si=VkQdqu6rh5XhNa41 Best wishes Munishwar Vasudeva Director Lotus Harvestec Pvt Ltd

In the ongoing efforts by the Ministry of Food to reduce chemical fumigation in the Public Distribution System (PDS), one critical aspect has come into focus—cross infestation in conventional bagged storage warehouses. As a part of the Ministry’s initiative, I’ve been actively involved in discussions exploring alternatives to chemical-heavy practices and improving storage hygiene. These discussions have led to a deeper understanding of how strategic warehouse design can significantly minimize storage losses. The Core Issue: Cross Infestation Cross infestation is often the root cause of post-harvest storage losses. Insects migrate between stacks and batches of grain, leading to contamination and compelling storage managers to rely heavily on phosphine fumigation. This recurring exposure not only compromises grain quality but also raises concerns over chemical residues and environmental impact. But what if we could prevent cross infestation at the source—through warehouse design itself? Proposed Warehouse Design for Infestation Control A tentative design was conceptualized to enable efficient mechanization of loading, unloading, and stacking, while also addressing the issue of cross infestation and enabling chemical-free operations. Here’s a glimpse into the proposed structure: 🔹 Airtight Warehouse Building The warehouse is fully airtight to ensure controlled airflow and sealed internal conditions. An isolation zone with double doors is planned at the entry point. This serves as an airlock chamber to maintain internal air pressure while allowing uninterrupted operations. 🔹 Air Circulation & Pressure Control An optimally designed intake fan is proposed to be installed on one side of the building. The fan is rated for a warehouse volume of 150,000 cubic meters (approx. 200m x 50m x 15m). It delivers an airflow of approximately 158,000 CMH while maintaining a pressure of 1 mm of water gauge. Motor rating: 60 HP. The intake air is passed through filters to eliminate the entry of any insects or foreign particles. On the diagonally opposite side (roof or wall), an electrically controlled louvre is integrated to: Maintain internal pressure balance. Facilitate night-time cooling while avoiding day-time heat entry. Ensure one-directional airflow, which helps isolate potential infestations. This strategic airflow setup creates an environment where insect movement is disrupted, preventing cross-stack infestation and reducing the need for repeated fumigation. Scope for Controlled Fumigation While this design primarily targets infestation prevention, it also opens doors for optimized and safer phosphine fumigation, if required. The airtight nature of the structure allows for controlled, uniform fumigation with minimal chemical usage, thus supporting the broader goal of reducing chemical dependency. Further technical discussions are planned with fumigation experts to assess the feasibility and safety of integrating such systems within the proposed design. Acknowledgment Special thanks to Mr. Raj Kumar Singh of Perkins Blowers Co., Sonipat, Haryana, for his precise calculations and technical expertise in designing the fan system that forms the backbone of this concept.

🔍Smart Aeration Practices: A Cautionary Note for Silo Grain Storage This week, I’d like to take a moment to remind the grain storage fraternity about the critical importance of a cautious and data-driven approach to aeration when managing food grains stored in bulk in silos. ⚠️ Why Aeration Demands Caution While aeration is often considered a routine step in grain management, it should never be treated casually. Our internal analysis, backed by key datasets, highlights why aeration must be applied with precision—or not at all. The three key factors that guide our aeration strategy are: Equilibrium Moisture Content (EMC) Warehousing Shelf Life Duration (based on moisture content) Weight Loss During Drying These parameters consistently discourage casual or partial aeration—regardless of external temperatures. 🌫 The Danger of Incomplete Aeration Cycles When ambient temperature falls below 15°C, many look to atmospheric humidity as a trigger for aeration. However, humidity levels fluctuate significantly between day and night, often causing unintentional pauses in aeration for hours—or even days. These pauses can be extremely harmful. During such interruptions, a “moisture zone” forms within the silo, ranging from 1 to 12 inches thick and containing moisture levels between 16% and 20%. This pocket of high moisture causes more harm to the grain than any intended benefit from aeration. ✅ Key Aeration Checklist Before You Begin Ensure the aeration cycle can be completed in one go—no pauses or breaks. Calculate the full cycle duration based on silo volume and aeration fan CFM. Factor in energy consumption—aeration isn’t free and can be costly over time. ❄️ Consider a Smarter Alternative: Grain Chillers In winter, switching to grain chillers can be a more energy-efficient and safer method. With ambient temperatures already lower, chillers can: Reduce operational cost by at least one-third Maintain consistent grain temperature Avoid the formation of moisture zones altogether Final Thoughts: Aeration is not just about switching on the fan when it feels cold outside. It’s a calculated decision, guided by moisture content, airflow capacity, and uninterrupted execution. A pause in aeration is more than a technical glitch—it’s a biological risk. Let’s be mindful, analytical, and efficient in how we manage the grains that feed millions.

My upbringing at village level specially during my school holidays still has lasting impact on my Agro Business ventures. Professional qualifications at graduate level did make me ponder on various important factors of balancing the income of the farmers and processors. My accidental tenure with Basmati milling made me fall in love with the Rice Milling. I did accept lot of challenges the Basmati fraternity and was blessed to conquer most of them. I would like to express my technical instinct which is worth considering and make best of it. The “Energy Balance” meaning the milling operations can be managed within the available calorific values equivalent power generation capability. Millers would certainly boost its margins if surviving within this limit. If at all if the husk is not sufficient for the requisite power generation, the paddy straw power generation can also be considered by adapting dual furnace. Considering this proposition, it is a win-win situation for farmers, processor and positive impact on environment. Just hold a meeting with your Rice Mill equipment supplier and audit the possibilities of optimizing the power consumption. Discuss the power generation from higher pressure boiler with back pressure steam.   A case study: Paddy Straw to Paddy Ratio: 1.4 to 1 125000 MT ton paddy 14 MW power generation which is 9 Kw per ton. About 3636 tons of husk production can generate 1.5 MW power. Activated Carbon, Amorphous silica, crystalline silica are by products. 500 TDP rice mill need to be generating its own power.

When it comes to bulk grain storage in silos, discussions often revolve around aeration, fumigation, and structural integrity. Yet, the most underrated—but crucial—element is the Temperature Monitoring (TM) system. Many silo operators invest in TM systems, but unfortunately, that’s where the precision often ends. Improper installation, insufficient number of sensors, or poorly placed cables—especially across the height and diameter of the stored material—render the system ineffective. A TM system is only as good as its installation and configuration. Why Temperature Monitoring is Essential: Temperature Monitoring is the most reliable non-invasive method for assessing the health of stored grains. More than just a display of numbers, it acts as an early warning system—providing real-time data that helps detect potential issues before they escalate. A temperature rise in any section of the grain mass is usually the first sign of trouble. It can signal: Development of hotspots Onset of insect infestation Moisture accumulation due to condensation, uneven grain moisture, or even leaky silo sheets When correctly installed and monitored, your TM system doesn’t just alert you to issues—it guides you in applying targeted corrective actions. Common Mistakes in TM System Implementation: Despite its importance, TM systems are often misunderstood or underutilized. The most frequent issues include: Inadequate number of sensors based on silo size Incorrect sensor placement, ignoring depth and diameter coverage Improper cable anchoring, causing them to shift or collapse under grain pressure Software misconfiguration, leading to missed alarms and data misinterpretation Proper installation ensures the sensors maintain their position despite grain pressure and continue to deliver accurate readings. This is the foundation of a trustworthy TM system TM System: More Than Just Monitoring: Think of your TM system as your grain storage’s command center. With the right setup: It offers real-time visibility into the condition of stored grains Prevents over-aeration or poorly timed aeration Reduces reliance on guesswork or frequent manual inspections Helps maintain grain quality, reduce losses, and improve ROI Half the Job is Installation, Half is Configuration: Even the best hardware fails if the software doesn’t alert you when something’s wrong. Custom-configured alarms for temperature thresholds and rising trends are essential. Your TM system should: Highlight abnormal patterns Alert you when conditions cross safe limits Log historical data for audits and analysis Corrective action begins with detection, and that starts with a well-designed TM setup. Visual Guidance: Below is a recommended cable placement diagram that shows optimal sensor distribution across silo height and diameter.   In silo management, what you don’t see can hurt you. Temperature Monitoring is not an optional feature—it’s a necessity. When done right, it becomes your first line of defense against spoilage, infestation, and moisture-related losses. Let’s stop treating TM systems as an accessory. It’s time we make it central to our bulk storage strategy.

Introduction: Paddy is unique among food grains due to its post-harvest behavior, especially its moisture sensitivity. Efficient handling and drying play a crucial role in ensuring high-quality rice production and energy-efficient processing. All the food grains except paddy are lesser complex. Paddy needs some extra care to make best out of it commercially as well as technically. The toughest part of handling the paddy is moisture management. Be it from the field after harvesting or receiving the high levels of moisture at the mill. Paddy above 20% needs a careful handling. The moisture we measure e.g. 12% is always a weighted average where the range of moisture may be between 11 to 14%. Single grain moisture meter measuring the moisture of 100 grains give much better idea about the range. The regions where the paddy moisture during harvest season is more than 20% as an average and 25% as maximum need to be carefully handled. The diagram as a layout is suggestively recommending how to sort the moisture ranges of 2% each and dried separately. The mixture of 12 to 20% will consume more energy for drying and would have moisture of grains below 12% and still undried kernels above 13% as well. The layout is simple with minimum level of automation; one can fully automate it as well having single chain conveyor with single elevator. Key Benefits of Moisture Sorting: Reduces energy consumption during drying Prevents over-drying (which leads to cracks and quality loss) Improves mill efficiency and final grain quality Helps avoid mold formation and spoilage during storage Tips for Moisture Sorting: 🌾 Tip: Always sort paddy by 2% moisture ranges (e.g., 12–14%, 14–16%, etc.) before drying to optimize energy use and preserve grain integrity. Conclusion: Reinforce the takeaway and suggest potential next steps or tools. With simple layout modifications and strategic sorting based on moisture ranges, both small and large mills can improve the technical and commercial value of paddy. Automation can be introduced gradually to scale operations.  

As per the last week blog: https://lotusharvestec.com/storage-technicalities/ Three datas like EMC, Warehousing duration and Weight loss upon drying burst myths of aerating the silos. By aeration of the silos we expose our stored food grains to atmospheric reactions which is as good as open stack storage. Scientific storage has its fundamentals which needs to be followed religiously. Doing partial aeration is the worst sin as a storage technician we can commit. If we have to do the aeration it needs to be done fully as the moisture zone is formed which shall escape from the top with a full aeration cycle. Moisture zone about six inches with about 18% spoils the grains because of obvious reasons. Aeration does cost money, so please be sensible. Aeration as per my experience is a firefighting system which we pray not to use.

Three essential technicalities are required to be considered for a sensible storage which are: 1.Equilibrium Moisture content 2.Shelf life of grain as per its moisture content 3.Dry matter loss as per moisture removal Moisture content for a long term shelf life of a grain beyond 90 days is 12% or below which can only happen in a bulk storage either under normal ambient conditions or chilling conditions EMC Equilibrium Moisture Content (%wb*) at 25°C Grain 30% RH 40% RH 50% RH 60% RH 70% RH 80% RH 90% RH 100% RH Barley 8.5 9.7 10.8 12.1 13.5 15.8 19.5 26.8 Shelled Maize 8.3 9.8 11.2 12.9 14.0 15.6 19.6 23.8 Paddy 7.9 9.4 10.8 12.2 13.4 14.8 16.7 – Milled Rice 9.0 10.3 11.5 12.6 12.8 15.4 18.1 23.6 Sorghum 8.6 9.8 11.0 12.0 13.8 15.8 18.8 21.9 Wheat 8.6 9.7 10.9 11.9 13.6 15.7 19.7 25.6   Shelf Life at Various Moisture Levels DURATION OF WAREHOUSING (in days) Source: FAO Agricultural Services Bulletin no 93 TEMPERATURE MOISTURE 5°C 10°C 15°C 20°C 25°C 30°C 13% 180 115 90 14% 160 100 50 30 15% 100 50 30 15 16% 130 50 30 20 8 17% 65 35 22 12 5 18% 130 40 25 17 8 2 19% 70 30 17 12 5 0 20% 45 22 15 8 21% 30 17 11 7 22% 23 3 8 6 23% 17 10 7 5 24% 13 8 4 4 25% 10 8 6 3 Dry Matter Loss As Per Moisture Removal Moisture Loss (kg/tonne) Initial Moisture Content % (wb) 19 18 17 16 15 14 13 12 11 30 136 146 157 167 176 186 195 205 213 29 125 134 145 155 165 174 184 193 203 28 111 122 133 143 153 163 172 182 191 27 99 110 120 131 141 151 161 170 179 26 86 98 108 119 129 140 149 159 169 25 74 85 96 107 116 128 138 148 157 24 62 73 84 95 105 115 125 135 145 23 49 61 72 83 94 105 115 125 134 22 37 49 60 71 82 93 103 113 124 21 25 37 48 60 70 81 91 102 112 20 12 24 36 48 58 69 80 90 100 19 – 12 24 36 47 58 69 79 90 18 – – 12 24 35 47 57 68 78 17 – – – 12 23 35 45 56 66 16 – – – – 12 23 34 45 55 15 – – – – – 12 23 34 45