cold store

CONTROL PANEL BRACKETS

When you want to protect something, you lock it. So why should it be anything different with your mobile system control panels? Barpro Johannesburg receives a number of call-outs, where the control panel at the back of the mobiles were not closed for various reasons. This gives unwanted guests the opportunity to tamper with the electronics and cause overloads and motors to burn out.  When there is unauthorised human intervention in control panels, risks to safety interlocks are increased. This can result in damage & injury. As a collective effort with our technical team, we have designed a bracket to act as a secondary locking system. It has no wearing parts and is made out of 3mm steel. We have already installed over 50 of these units recently. For less than R600 you will have a steel bracket with a lock (all keyed alike) installed in your store. This is less than the cost of one Siemens overload. Installation is quoted separately, and costs are depended on the size of the store. We have found that the number of call-outs, just in one particular store, have come down dramatically and repair costs have been significantly reduced.  Our experienced technical team can assist with this solution. Give us a call at (011) 392 1702 – Corne Stapelberg

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Lithium takes charge

Humanity has been fascinated by electricity for a long time. The word itself comes from the Greek “electron” which means amber as small particles were seen to stick to amber once it had been rubbed. It was the American Benjamin Franklin who first referred to an electric “battery “using the term in a letter to humorously suggest that electrical experimenters should receive battery salute for their successes. Although he was referring to an artillery battery, the same term was then applied to his glass, lead and brine system to store electricity for future use. As the storage of electricity is central to the modern world’s attempts to wean itself off fossil fuels, there has been huge interest in developing new battery chemistries to allow for the efficient storage of electrical energy in a multitude of applications. For materials handling equipment in warehouses, especially in those applications where electrical as opposed to diesel or gas power is required, including cold and freezer stores, batteries have traditionally been of the lead-acid type. Lead-acid batteries are heavy, weighing over 1000kgs for counterbalance forklift applications, require special well ventilated charging areas as they give off noxious gases when charging, as well as heat. They also require constant maintenance to check the sulphuric acid electrolyte levels and to balance the electrical discharge from the individual battery cells. In tough cold storage applications, lead-acid batteries with good maintenance should last for approximately 8000 hours of operation. When charging they can store about 70% of the electricity supplied with the rest ending up as heat, requiring a cooling-off period before use. Where forklifts and other materials handling equipment is being used on a multi-shift basis, each vehicle should have three lead-acid batteries, one on an eight-hour charge, one cooling off and one in use on the machine. Battery changes have always been difficult given lead-acid battery weights and sheer size. All these activities require a substantial non -productive area in warehouses and cold stores. Balancell, established in 2008 by Dr Ian de Vries, is based in Paarden Eiland, Cape Town. Its original objective was to design and fit monitoring equipment on warehouse motive batteries. While this proved difficult due to the tough environment, battery recharging heat, freezing temperatures in cold stores and corrosive sulphuric acid, the information received from the ruggedly designed solid-state battery monitors enabled lead-acid batteries to function more efficiently, in some cases doubling their useful lifecycles. Being involved with motive batteries, Dr de Vries identified the advantages of the new Lithium Ferro phosphate batteries (LFP). These should be distinguished from Nickel Manganese Cobalt Oxide (NMC) batteries which are used in lightweight applications like tablets and cell phones. LFP batteries, while heavier than the NMC variety, are more chemically stable and are inherently safe.  They will not self ignite nor burn if punctured or crushed, making them ideal for materials handling equipment. Balancell is now manufacturing battery packs at its Cape Town factory using LFP cells imported from China, which incorporate the original monitoring equipment as adapted for the new battery chemistry.  In comparison with lead-acid batteries, LFP batteries with the same amp-hour rating are typically a quarter of the size and weight. On charging they produce no gas, so don’t require a special charging area. They also thrive on opportunity charging, typically during lunch and tea breaks. Normal charging takes about two hours as opposed to eight for a Lead acid battery and is 95% efficient meaning minimal heat is emitted. An LFP battery has powered a forklift for 23 hours on one full charge. However LFP batteries don’t like being left for long in a discharged state, so the battery monitoring unit warns the driver and shuts them down at 10% of capacity. Pricewise, LFP batteries are approximately double the price of their lead-acid equivalent. But their life cycle is up to 2.5 times longer meaning that a forklift should only require one battery in seven years. Forklifts using the lead-acid variety require three batteries which will on average last for three years. No special battery charging areas are needed and the health and safety aspects of gassing, spilt acid and the sheer difficulty of battery changes are removed. All the forklifts at Cape Fruit Cooler’s new high volume throughput Richmond Park facility are powered with Balancell’s LFP batteries. Please click on the attached link: https://www.youtube.com/watch?v=7eRCeEHzfsQ&t=47s/ For more information on Balancell’s new batteries, why not contact them at info@balancell.com . John Petrie, with a lifetime’s experience in materials handling equipment, is now consulting for Balancell. He can be contacted directly on 082 907 0994 or johnpetrie@balancell.com

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Freezer Containers Vs. Freezer Stores

Pictured: Freezer Container (Source) In Luanda and Lagos there are companies that stack old freezer or reefer containers (6 and 12 meter) up to 4 high and use them mainly for the storage of frozen chicken. Companies with limited cold storage requirements in South Africa also use reefer containers for the same purpose but on ground level only. Reefer containers can be used to store frozen foods on shore but they are problematic when used as a long term solution. Reefer containers are designed to keep product at the same temperature as when the container was loaded so long as the doors are kept closed and sealed. They are not designed to decrease product temperatures. When used as cold stores in Lagos and Luanda, frequent door openings quickly allow the cold air to escape and raise product temperatures which can cause product to go “off”. The containers stacked off the ground are normally accessed by means of ladders which cause additional delays in loading and offloading. Reefer containers, when properly sealed and with good insulation can use around 5 KW of electricity per hour. If left sealed, the refrigeration unit will come on only as required to maintain the set temperature. The use of old reefer containers for cold storage is not recommended. The insulation and door seals degrade over time. It is difficult to keep the T section floor clean and hygienic. Power usage is high. Stock inside the container is difficult to access. While it is possible to upgrade containers with smaller doors and refurbished refrigeration units, purpose built cold stores are a better long term solution. An energy usage comparison between a freon cold store and reefer containers from refrigeration consultant Christo van der Merwe is attached as is a cold store design for 208 pallets using Storax mobiles.   Christo says, I have looked at 10 x containers at 20 pallets/container vs 1 x 200 pallet freezer store operating at -20°C. Containers Containers have the following limitations: They can hold product that is on temperature but they are not designed to cope with warm product being loaded above the holding temperature. You have access to the 2 x front pallets and if you want to access a  pallet that is stored in the back of the container you have to remove all the containers loaded in front of it. The loss of temperature can be dramatic is every pallet is unloaded to access a pallet at the back and then the remaining pallets are loaded in again-it will take time to regain room temperature. If there is any refrigeration equipment failure then the container has to be emptied until the component is repaired. Refrigeration system The container refrigeration system for a 40 ft (12m) container = 20 pallets at -20°C has a cooling capacity of ± 4.5 kWR. The refrigeration system has a power consumption of ± 5 kW depending on manufacturers specs but at best we can expect a COP of 0.9 in summer conditions. For 10 x containers the total power consumption will be ± 50 kW. 200 Pallet Freezer Store (mobile racking) The 200 pallet freezer store is fitted with mobile racking so we have the smallest possible foot print.   With mobile racking you have access to every pallet position. Double handling of product can be avoided The refrigeration system generally has some redundancy so if there are any equipment failures then the store will still operate but it will lose a bit of temperature. The system generally has pull down capacity so some warm product can be loaded into the store without affecting the room temperature too much. Refrigeration system – Freon The freezer store refrigeration system is based on ± 28 to 30 kWR which is required to maintain temperature with no product being loaded. The refrigeration system has a power consumption of ± 27 kW which includes evaporator and condenser fans so a COP of ± 1.04 Refrigeration system-Ammonia (for interest) The freezer store refrigeration system is based on ± 30 kWR which is required to maintain temperature with no product being loaded. The refrigeration system has a power consumption of ± 18 kW which includes evaporator and condenser fans so a COP of ± 1.66 (so 40% lower power consumption). In Summary   Power consumption for 10 x containers = 200 pallets ± 50 kW = 277% Power consumption for 200 pallets freon freezer store ± 27 kW = 150% Power consumption for 200 pallets ammonia freezer store ± 18 kW = 100% Picture Source Optimise space in your Cold Storage Facility – Contact Us [gravityform id=”10″ title=”true” description=”true”] Read more: Sequence Logistics expands to Johannesburg Read more: Repairing non-Storax Racking Systems Read more: A space saving, efficient and cost effective solution to case picking in cold stores  

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