By Andrew Lee, Technical Director, BDC Systems, UK
Climate change and the wet harvest weather in the UK and parts of Europe this year have highlighted the need for grain driers to become a key component of post-harvest equipment.
The first Svegma drier was installed in the UK over 40 years ago and there are now over 1,000 installations which are successfully meeting the grain drying needs of commercial grain operators, farming co-operatives, maltsters and farmers.
The market leading Svegma continuous flow drier was developed by Svegma over 60 years ago to overcome the challenging and difficult drying conditions in Scandinavia, where the moisture content (mc) of grain is generally high.
Akron’s acquisition of Svegma in 1992 triggered a leap forward as the driers were subsequently fitted with Akron’s own high-efficiency fans and heat production technology. Today’s Svegma drier is still based on the original design – proving the accuracy of the original designs around crop flow and airflow.
Svegma’s state-of-the-art production facilities feature the latest Computer Numerical Control (CNC) machines, ensuring that all components meet the exacting quality and performance standards associated with the Akron Svegma brand.
All parts are manufactured for stock and stored in temperature-controlled warehousing allowing customers short delivery schedules to be met.
Construction
Svegma driers are manufactured from heavy gauge galvanised sheet guaranteeing long life and durability. BDC supplied two new Svegma driers in time for harvest 2022 to Weald Granary, a farmer owned grain storage, marketing and distribution co-operative, to replace Svegma driers installed 35 and 34 years ago respectively.
“There is no question that our old Svegma driers had served us well,” said John Smith, Weald Granary’s managing director. “Located outside of our grain store they had been exposed to the elements for over 30 years and had many hundreds of thousands of tonnes of grain and maize go through them. It was no surprise that they reached the end of their lives!”
Their construction allows the Svegma driers to be installed inside or out without the need for cladding. If planning or environmental requirements have to be met then driers can be clad with coloured sheeting.The compact design and modular construction of Svegma driers provide flexibility of installation within confined spaces and allow for easy future extension.
Fans
A major differentiator for the Svegma driers is that Akron has 50 years’ experience of mastering the flow of air and has devoted tens of thousands of hours into research and development of fan technology for both the agricultural and industrial sectors.
To support Akron’s fan design process, it has one of Northern Europe’s largest and most versatile fan testing facilities on site, where all types of output, acoustic and efficiency properties can be tried and tested.
This has resulted in the Svegma driers having a unique selling point (USP) – their highly efficient slow running axial flow fan units have been designed, by Akron, specifically for the Svegma driers so that they deliver high performance at minimum noise levels. Other grain driers on the market are fitted with ‘off the shelf’ fans which have to work with the drier rather than having been designed for the drier.
Turboclean dust extraction fans are also available to meet exacting environmental standards on both noise and dust emissions. The Turboclean is a combined fan and extraction unit intended to separate dust from contaminated air.
The dust extraction is achieved by centrifugal force pushing dust particles to the outside of the casing where they are skimmed off into the outer scroll leading to the cyclone. The cleaned exhaust from the cyclone is recirculated back to the Turboclean inlet and the dust drops out of the bottom of the cyclone.
Continuous mixed flow
The proven continuous mixed flow design of Svegma driers allows them to operate at their optimum efficiency with low power consumption and minimum maintenance as there are no moving parts in the drier column.
The grain flows over special tapered air laterals, and a series of hot air inlet laterals are followed by exhaust outlet laterals. This is repeated throughout the grain column and the tapered laterals are staggered to ensure an even airflow and uniform drying and mixing of grain. Hot air half laterals are fitted to the side walls of the drier to prevent condensation and streaming of grain.
Importantly, there are no fixings, flanges or ledges in the grain column allowing continuous unobstructed grain movement. This is crucial when drying specialist seed crops to avoid contamination.
The Svegma’s grain column comprises a roof section with an access door to the drying column, buffer, drying and cooling sections above the discharge unit. Sight glasses allow visibility of the grain level throughout the column.
Discharge
A fully galvanised discharge section with either pulse roller or shutter discharge provides positive, even grain movement throughout the grain column. A single lever operation is all that is necessary to clean out the drier between crops. Sight glasses and access doors in the discharge hopper provide easy inspection of the crop leaving the drier.
Burners
Nu-Way multijet burners, for oil and gas, provide Svegma driers with a full temperature range. Two stage high/low or three stage burners are also available. Stainless steel furnace tubes with turbulator air mixing and swing down burner plates allow for easy cleaning and maintenance. Indirect burners are also available.
Control Panel
Svegma driers have a touch screen panel with PLC control which is simple to operate, showing the constant status of the drier, incorporating fail-safe auto shutdown facility. The handling equipment taking grain to and from the drier can also be incorporated into the control system to enable centralised control of the entire plant. The control system delivers remote operation which allows the operator to monitor and adjust settings remotely.
Integrated Moisture Monitoring System
BDC has continued to develop its Moisture Monitoring System (MMS) and it now has the capability to control the discharge rate of the Svegma drier based on the moisture content of the crop, rather than the exhaust air temperature.
The BDC MMS enables drier operators to accurately, automatically and remotely check the mc of dried grain as it enters storage. Preconfigured times for the delivery of screen shots of the Svegma’s control panel, highlighting mc details from the MMS, via email to any mobile device, mean that there is no longer the need for anyone to be on hand at the grain plant to manually check levels and make any necessary changes. Valuable manpower resources can be assigned to other more revenue generating tasks.
Using bespoke sampling units designed and developed by BDC, the MMS takes grain from both the incoming (wet) elevator and outgoing (dry) elevators. These samples are then processed through a multi-chamber duct incorporating a Sinar Technology moisture probe, specifically designed for use with the MMS.
Live readings showing the mc of both samples, in a percentage format, are displayed on the Svegma’s control panel screen together with a graph showing the moisture trend. Historical data is stored in the control panel’s memory for future reference.
Not only does the BDC MMS monitor the mc of the crop going into and out of the drier, it automatically controls the discharge rate of the Svegma, should the mc fall below or rise above the predefined levels, ensuring that the crop is discharged at a constant optimum mc.
The MMS’ ability to automatically control the Svegma means that the drier’s energy efficiency is greatly improved. Costly energy is not wasted by over-drying. Svegma driers are available in multiple sizes and configuration, with a capacity from 5tph to over 100tph and a range of heating, control and automation options.
Reducing energy costs is a key focus for everyone, and improved fuel usage can be achieved via the Svegma’s automated burners using alternative fuels including HV02 vegetable oils or cleaner fuels such as Kerosene oil.
If you are thinking about upgrading your grain drying facilities for harvest 2024, you should talk to a grain handling specialist with a proven track record of successfully delivering solutions for commercial grain operators, farming co-operatives, maltsters and farmers.
A specialist who will listen to you, understand your individual requirements and deliver a future proofed solution that delivers not necessarily what you thought you wanted, but what you actually need. It is important to remember that as with all solutions one size rarely fits all, and this is especially true when it comes to grain driers.
