DSH Systems FAQ: Your Questions Answered

Getting Started.

  • If you are just staring an enquiry with DSH, we recommend letting us know about your site specifications (including any issues like space or access constraints), product type, flow rate and bulk density, as well as any other requirements or information you think is important.

    Once we receive your enquiry, you will hear from either us directly, or from your local DSH distributor. Based on the information you provided, we will look into whether a DSH System is the best solution for you, and start the process of quoting.

    If you would like to start proceeding with an order based on this initial enquiry, DSH or our agent will generally request the completion of a questionnaire form that requests all the information required to correctly assess if a DSH system is suitable. We then use this information to determine what size and hopper configuration would be most efficient.

  • DSH hoppers work well with a wide range of dry, granular, free flowing products, but generally not with fine powder, sticky, fibrous or very lumpy products.

    Products we have tested include the following:

    Grains & Foods

    Barley (Feed, Malt, Pellets), Bran (Pellets), Broll (Milling), Canola (Meal), Corn (Crushed, Gluten, Gluten Feed, Gluten Meal, Meal, Meal Pellets, Crushed Cobs, Germ), Cotton Seed (De-linted), Dried Distillers Grain (DDG), Feed (Ground, Pellets, Feed Phosphate), Germen Malta, Grains,Maize (Maize Gluten), Meal (Pellets), Rape Seed (Rapeseed Meal), Rice (Hulls), Salt (Table), Soya (Beans, Hulls), Soyabean (Bean, Meal, Pellets), Stock Food, Sugar (Pellets, Raw, Refined), Sunflower (Pellets), Tea, Wheat

    Minerals & Quarry

    Gravel, Kaolin, Limestone (Sand), Magnesite, Marble Powder, Olivine, Salt (Coarse, De-icing), Sands (Various), Silica Sand, Wood (Pellets)

    Fertilisers

    Bauxite, Blue T Super, Bourucca rock, Charcoal (Granulated), DAP, Dicalcium Phosphate, Dolomite (Crushed), Dolomite Lime, Feldspar, Fertilisers, Kieserite, Lime (Granular, Powder), MAP

  • Absolutely. We are always interested in testing new products with our systems. Get in touch with us to arrange.

  • Flowrate is the mass or weight of product per hour that the hopper can transfer. It can be expressed in:

    Tonnes per hour (1 tonne = 1000 kg)

    British Tons per hour (1 British ton = 2240 lbs)

    US Short Tons per hour (1 US Short ton = 2000 lbs)

    Bushels per hour (grain) (1 Bushel = 1.244 ft³ or 0.0352 m³)

    In New Zealand (where DSH Systems Ltd is based) we use the metric system; however, we are able to converse and convert into any unit used in other countries.

  • There are two ways to determine system flowrate.

    The first is referring to the conveyor or valve manufacturers specifications OR the plant or equipment records (note that most conveying systems do not run at the manufacturers maximum design capacity, but at a lower capacity)

    The second (and preferred) method is to physically measure the flowrate, where possible. To calculate this, divide the time it takes to fill a truck/silo etc. in hours by the net product weight (tonnes or tons). Remember to only include the time that the product is continuously flowing and deduct any time periods in which the product is not flowing.

  • DSH Hoppers perform best and minimise dust emissions when operating at a consistent flowrate in the range of 80-100% of design capacity. An accurate flow rate means the hopper will be correctly sized, operate correctly from day one and functions at its optimal rate, thus reducing dust more efficiently.

  • Bulk density is the mass or weight of the product per litre, cubic meter, or cubic foot. When we refer to bulk density, we are interested in the loose bulk density, i.e., when the product is poured into a pile on the floor or into a container, without any consolidation, compaction, or vibration, as this best reflects the state of the product as it passes through a DSH hopper.

  • Product bulk density can be affected by moisture and oil (grains) content of the product itself and there can often be variations from one application to another even when handling the same product. As it can vary significantly, it is important to verify your bulk density by measurement on site, where possible.

  • Our preferred way to measure bulk density is the following:

    Take an empty container of known volume and place it on accurate scales of suitable rating.

    With the container on the scales, tare to zero.

    Pour the product into the container until it is flat and level with the top (or a volume mark). Do not compress or compact the product.

    Record the net weight of the product.

    Divide the product net weight by the product volume to give grams or kilograms / litre (convert units if necessary).

  • We use the flowrate and bulk density of products to calculate the size of the hopper and the size and number of springs required, to ensure that we provide the best system for your application.

    The hoppers’ ability to reduce dust is only as good as the information we receive, so it is important to be as accurate as possible. We are always available to discuss any questions you might have in calculating the above, as we want to make sure that we are providing the best system for the job.

Common Questions.

  • We can install a DSH in existing or new sites, and since hopper systems are fully customisable, we can make sure they fit perfectly. If you are interested in having a DSH System installed, we just need your site specifications (including any issues like space or access constraints), product type, flow rate and bulk density.

  • The DSH is available globally, and We have a worldwide network of trusted DSH agents. If we don’t have a supplier in your country, contact us directly, and we’ll see what we can do.

    Interested in becoming a DSH supplier? Get in touch!

Troubleshooting.

  • There are a number of issues that can cause a loose column. We suggest working through the following, carefully making adjustments and testing between each. For more advice, please contact us.

    1) The gap between the Plug and Hopper is not correct

    Using the adjuster bolts and chain links to position the Plug so that the Hopper fills to at least 70%.

    2) The Plug may be off centre above the hole

    Ensure the gap between the Plug and the Hopper is even around the entire circumference of the Plug.

    Make sure the product is not pushing the plug off centre; centre the flow of product into the centre of the plug.

    3) The product may not be falling into the centre of the Hopper

    Check that centre of the product flow is landing in the centre of the Hopper. If not you need to move the Hopper or the load out point.

    Make sure the Hopper is level when operating and that the Plug is centred over the Hopper hole.

    Ensure product is evenly distributed over the width of the conveyor

    4) The product may be surging into the Hopper

    Ensure that product is loading, evenly and continuously. Check your system for surging or flushing and correct this.

    5) There maybe a blockage in the Hopper

    Empty the Hopper and ensure it is clean, with no blockages, or build up inside or on the bottom of the plug.

    6) The Hopper may be misshapen

    Ensure the Hopper outlet is circular in shape.

    7) The outlet rim of the Hopper may be damaged

    Ensure the rim is smooth and even, especially if you have cut this surface.

  • 1) The gap between the Plug and the Hopper is not large enough.

    Lower the Hopper on the Adjuster Bolts, this opens the gap between the Hopper and the Plug, thus allowing better flow from the Hopper.

    2) Product is not landing in the centre of the Hopper.

    Check that the flow of product into the Hopper is evenly distributed and landing on centre. Adjustments may need to be made to the position of the Hopper under your load out point, or the position of your load out point. You may need to look at how evenly the product is distributed on the conveyor.

    3) Product is damp or clumping.

    Ensure your product is dry, so that it does not clump and cause blockages between the Hopper and Plug • The Hopper works best with dry, free flowing products.

    4) Product is surging into the Hopper.

    Make changes to ensure that the flow of product into the Hopper is smooth and continuous. A surge can occur at initial loading, continue to load, when set correctly a column will form after initial loading surge and overflow.

    5) There is a blockage or build up within the Hopper.

    Check the gap around the plug for lumps or build up on the inside of the Hopper. To clear the Hopper a slap with hands is usually sufficient to clean the Hopper, never hit with hard or sharp objects.

    6) Check the underside of the Plug for build-up.

    7) The tonnage is too great for the size of Hopper.

    Confirm that the load out tonnage that you provided to DSH Systems is the same as you are attempting to load. DSH Systems come in a variety of sizes, your size requirement is based on your load out tonnage and the bulk density of your product.

    8) If the Hopper continues to overflow, the bottom of the Hopper may need to be cut, but only as a last resort. Before doing so check with DSH Systems or your distributor to discuss the problem.

  • 1) The tonnage is too large for the opening in the Hopper

    Confirm that load out tonnage that you provided to DSH Systems to determine your DSH System size is the same as you are attempting to load.

    2) Confirm that your adjustors are set at maximum.

    3) The bottom of the Hopper can be cut

    DO NOT CUT THE HOPPER WITHOUT ADVICE FROM DSH SYSTEMS

  • The gap between the Plug and Hopper is too large.

    Tighten the Adjuster Bolts up in small increments to reduce the gap between the Plug and the Hopper. The Hopper needs to be run at 70% to 90% full.

  • 1) The Hopper is not centred under the centre of product stream

    Correct the position of the Hopper under the conveyor to ensure the product is landing in the middle of the Hopper, or move the load out position.

    2) The product is pushing the Hopper to the side.

    Correct the position of the Hopper under the product feed to ensure the product is landing in the middle of the Hopper

    Move the feed position so that the centre of the product flow lands in the centre of the Hopper

    3) The slide gate is opening too slowly

    Speed up the rate at which the slide gate opens.

  • 1) Product is not landing in the centre of the Hopper

    Correct the position of the Hopper under the conveyor to ensure the product is landing in the middle of the Hopper.

    If the conveyors don’t have an even spread of product across the belt, this can cause loading on one side, correct the distribution of product into the Hopper.

    2) The Hopper has not been installed in a level position

    Confirm that all the Adjustor Bolts and Safety Chains are set at exactly the same level.

    When making adjustments ensure that changes are made to all similar components to the same degree.

    Confirm that the Frame has been installed in a level position, and adjust as required.

    3) There is a blockage or build up on one side of the Hopper or Plug.

    Check the gap around the plug for lumps or build up on the inside of the Hopper. A slap with your hands is usually sufficient to clean the Hopper, never hit with hard or sharp objects.

    Hitting the Hopper with a heavy object will forfeit your warranty.

  • The Safety Chains have been set too short.

    Lengthen the Safety Chains to drop the Hopper to ensure springs are never at full stretch but are taking the weight of the Hopper when loading.

    The maximum stretch allowed ny springs is 120mm (4 ¾”), springs will be damaged by over stretching.

  • Safety Chains have been set too long.

    Shorten the Safety Chains to lift the Hopper up to ensure springs are never at full stretch.

    The maximum stretch of the springs is 120mm (4 ¾”), springs will be damaged by over stretching and will require replacement.

  • 1) Your product may not be dry, free flowing and/or forming clumps.

    Check the moisture content of your product, DSH Systems work best with products with low moisture content.

    2) Check for blockages and remove

    Check if there is a blockage or build up within the Hopper.

    Check the gap around the plug for lumps or build up on the inside of the Hopper.

    Remove the blockage by slapping the Hopper with your hands, never hit with hard or sharp objects. Hitting the Hopper with a heavy object will forfeit your warranty.

    Check the underside of the Plug for build-up.

    3) The Plug is not centred above the Hopper outlet hole.

    Move the Hopper so that the distance between the Plug and the Hopper is the same around the entire circumference of the Plug.

  • 1) Check if there is a blockage or build up within the Hopper.

    Remove the blockage by slapping the Hopper with your hands, never hit with hard or sharp objects. Hitting the Hopper with a heavy object will forfeit your warranty.

    2) Check the gap around the plug for lumps or build up on the inside of the Hopper.

    3) Check the underside of the Plug for build-up.