Tuesday, January 30, 2018

Hey GrinderGuy, how do I make more consistent Mulch?


This was not my actual question. The question was how do I stop the spiking of oversize material through a screen on a grinder? It sounded just like most any mulch company in the Country reducing and regrinding.
Even though you are using a specific size screen, doesn’t necessarily mean all material will be less than that screen size. With pallet material or any other kiln dried or dried wood material, each piece needs to be cut and pushed through the screen. If you were using some type of green waste for example, because of the moisture in it, you would get a much finer product and more of a shredded product with that same size screen.
Those large spears getting through the screen are the same as any other Company will get.
Here are a few ideas of how to reduce them:
·         Make the initial grind smaller- This will keep the rotor area more full, and with less open space there is less of a chance of larger pieces being able to fall through the screen.

·         Make sure there is no way any materials can get from the infeed hopper onto the discharge belt without going through the screen. Make sure there are no gaps between the screens or between the screen and anvil/cutting edge.

·          You will get larger sizes when there is the least amount of wood in the grinding chamber. So if the infeed belt of the grinder is stopping and starting a lot it means the grinding chamber is emptying out so the hammermill can pick up speed. With little wood in the grinding chamber, the pieces have all kinds of open screen to fall right out. Slow the infeed enough so that it does not stop, or stops as little as possible and by keeping the chamber full and you will see a major reduction in the larger pieces.

·         Purchase or make Baffled screens. These are normal screens with flat stock welded to the back of the screen at the bottom of each hole row on an angle to stop any long pieces from shooting right through the hole. The spears hit the baffle and hold it so the hammermill can cut it again.

·         Keep the tips as tight as you can to the cutting edge and the screens. If you need to build up the anvil or cutting edge with hard surface more often that is what you need to do. If the tip is as close as ½” to the cutting edges you will get a clean cut. As you wear away the tips and the cutting edge the gap determines your initial size and you will get larger pieces that need cut again. A bead of hard surface across the screens in front of the row of holes will help also. This will make the screens more brittle so use a welder’s knowledge about heat on metals and only do a few inches at a time then move to a different part of the screen.

·         You will hear a lot of people say “Use round hole screens, they make the best product” when the fact is, the difference between a round and square hole screen is the amount of open area on the screen available for wood to go through. It is much less with a comparable round hole versus a square hole.

·         Rotate your screens if possible. The leading hole edge in the screen start to round as they wear. If you can flip them 180 degrees, you will be able to use the other end of the hole with a much cleaner sharper edge. Not all screens have the ability to do this.

·         Grind once instead of twice with a 2” or so screen. Then use about ¾” screens in a trommel or other screen to screen and produce your product. This has its own set of How- To’s but it can be an option.

·         Grind as normal and then screen the product to scalp off any of the oversize spears.

·         Use a smaller screen in the grinder- Not ideal. This would be the last resort.
That should be a good start and you should be able to find something that works for you or a combination that may work for you.

Questions?         Dave Whitelaw                                 grinderguy@askthegrinderguy.com

Hey Grinderguy, what are the proper Grinder Shutdown procedures?


                If you want to protect your investment, then you are asking the right questions. In the Owner’s Manual there is a lot of information including startup and shutdown procedures. You should make a checklist that operators need to complete at the end of each shift. Not only do these make sure your grinder is being taken care of, but you can also use them to figure out some of your costs and maintenance needs by including:
·         Operator Shift Hours
·         Grinder Hour Meter start and end
·         Fuel Usage
·         Engine oil Added
·         Engine Coolant Added
·         Hydraulic Oil Added
By including these items you may be able to determine:
·         What percentage of the day the grinder is actually running?
·         How much Fuel per hour the grinder is using on a particular product?
·         If fluid leaks are increasing?
As for the Grinder itself, or most any other piece of Equipment in a Grinding operation, what should be included on a Daily basis?-
1.       Hook up and pull the grinder out of the grinding area- Leaving it in place is nothing but a fire hazard that can transfer from equipment to equipment or materials
2.       Clean up and remove metal pile that was collected by the magnets on the grinder. Some of this metal may still be hot from being run through the grinder so pile in a safe, debris free area or container is best
3.       Clean Loose Debris from atop the Grinder- All this can be is a further potential fire hazard
4.       Blow off grinder and engine with an air compressor, even with leaf blower if needed. This includes the radiator, hydraulic cooler, fuel cooler, air filter, etc. Pay particular attention to the engine compartment, exhaust manifolds, turbos, etc.  This will keep fire hazards to a minimum and the engine running correctly
5.       Clean debris from rotor area and collection area under rotor and run discharge conveyors to empty the conveyor belts
6.       Fuel and grease Equipment- This allows the equipment more time to cool while you are still nearby just in case something was to catch fire.
7.       Check wear parts and change if necessary. May be too hot to do at the end of the shift but it is the best time to do it allowing more time for rotor area and engine to cool while you are still onsite
8.       If a water truck or water supply is near, hose down the rotor area and underneath the engine or bottom of engine compartment. Spraying water onto a hot engine can crack exhaust manifolds, so don’t do that, but wet down as many areas as possible. Better safe than sorry.
9.       Refer to the Owner’s Manual for Hourly Checklist per specific Manufacturers Recommendations
10.   Fire Extinguishers- How many? Are they charged? What was date of last inspection?
Most of this end of the day cleanup can be reduced by utilizing the wind on a daily basis:
·         Don’t set the grinder back up until morning when you know which direction the wind is blowing
·         Face the Radiator into the wind when you setup the grinder
·         Feed the grinder with the wind blowing dust and fines away from the engine
·         Push material to the grinder from a downwind position or from the side to help protect the support equipment also.
·         Use dust covers and dust hoods on the discharge conveyors. This will not only stop material from blowing off the conveyors but keep material from getting into the tail pulleys, belts and bearings.
·         Use a dust suppression system on the grinder if water is available.
Most all maintenance can be done after the shift so the next work day can get off to a good maintenance free start. Add the particulars of your grinder or shredder to your list and make your operators complete one daily. It not only makes sure your investment is being taken care of, but keeps you informed as to any maintenance items that may need attention and how productive your operation is during the work day.

Questions?         Dave Whitelaw                                Grinderguy@askthegrinderguy.com

Wednesday, June 1, 2016

Hey Grinderguy, how do I convert to grind shingles?

Being able to grind multiple materials reduces your grinding costs for everything you grind. So the more material ground the better. If you are a C&D Recycling Company for example, then you not only can separate the wood, plastics, metal and rock, but you can sort the shingles and be able to reduce your landfilling costs by lowering disposal weights. Even if you do not have an outlet for the shingles, mixing with small stone and making roads on your Landfill or site is a great option to eliminate this product after it is ground.
`But grinding shingles will wear out all the surfaces in your Grinder in a hurry and you will need a lot of water to keep the grinding chamber cool. This is the number one conversion you will need. Your radiator will plug solid with shingle dust and even dipping it may not fix it. Roofing tear off shingles are hard and brittle and the easiest to grind. Factory reject materials are much more difficult and if it is the middle of summer in the south, your ¼” ground shingle material will make one giant asphalt cone if you haven’t mixed in a little fine sand to stop it from sticking together.
 There are machines specifically made to grind shingles. On these machines, there are usually:
·         More replaceable wear plates
·         Can be different tips
·         Grinder Hammer pattern is made to keep materials away from the sidewalls of the grinding chamber to reduce wear on the outside surfaces
·         Top Fed rather than force fed with feed rolls. Gives materials time to fall through screen and reduces oversize product
·         Single discharge belt to reduce transfer leakage
·         Conveyor Belt Splicing is different to reduce fine material leakage
·         Heavy duty water spray system
among many other changes to maximize shingle reduction production.
So what do you change or what can you change to switch from grinding wood to grinding shingles? Each machine is different, some say run as is, not a good idea. Look for one that can reduce wear, increase production and is easily changed. You could purchase a shingle package grinder and then convert for wood, and then all the package options are already included. Here are some ideas:
·         Adding additional wear plates
·         Different rotor or rotor configuration with additional hard surfacing
·         Different belt splices
·         Deflector plates or screen to keep overs from mixing with finished product
·         Smooth belts not chevron patterns
·         Adjustable belt scrapers to keep as tight as possible to clean the belts
·         Water, Water, Water. Spray bars and enough water flow to keep the grinding chamber cool
Before you invest in this additional expense, make sure you have an outlet for materials. Even better, make sure you have two outlets, so when the first one disappears, you have another option. Use as an amendment to asphalt mix is great, but when the oil price drops and it is not worth the price to buy your material, the Asphalt plant will go back to straight liquid and leave your grinder worn and wet and covered in shingle dust.

Questions?                 Dave Whitelaw                 Grinderguy@askthegrinderguy.com

Sunday, May 1, 2016

Hey GrinderGuy, Why am I losing Production?

This operator is someone you should all hire. He is paying attention not only to maintenance, but to daily operations.
The question actually was, why am I losing production every time I install new tips or hammers on my grinder? So, the operator is not only taking care of routine maintenance, he is noticing that he is losing production at the end of the day. How can this happen?
Every time you install new hammers, tips, screens, cutting edges or worse, more than one of these at a time, your production will drop. This is because the new parts are much closer together, reducing the distance between the tip and the screen for example, which increases drag, reduces rotor speed and loss of production occurs. The more new parts, the closer the gap, the more drag occurs and less production is the result.
But is there a benefit? Absolutely
Because this distance is reduced, the product that is created is finer and more consistent.
If this is a regrind application, or is being screened to size, the spec product needed, may actually increase in volume as being more consistent, more material may pass through a screen rather than being scalped off.
Can you use this gap between the screen and tips to your advantage? You can in many ways.
If you are only reducing materials like logs, slabs or landclearing debris, and size is not an issue, a bigger gap will increase your production. Use old worn thin screens and shorter hammers or slightly worn tips. This will more eliminate the drag and the rotor or hammermill will rotate more freely and maintain rpm much better, increasing production.
If you tried the same as above on a regrind application, production will suffer and the material will be much finer with a lot more sawdust type finish product.
Keeping the gap tight by hard surfacing things like cutting edges and anvils, will produce a much more consistent product with less oversize pieces in finished product. If screening to size, you most likely will not need as large of a screening machine as these bigger pieces are reduced and the overall volume of material being removed is reduced so a shorter deck or drum can be utilized.
What to watch for?
The increased gap will allow for material to get between the tip and the screen. Not a big deal on strictly wood but there are materials that will ruin your day. Palm trees and palm fronds, along with some stringy, pliable type of woods and brush will squeeze into this gap, wrap around the rotor and stall it and the engine in about 2 seconds. Not a fun day when that happens.
On regrind, keep an eye on material daily. Pull a sample and pile side by side each day and you will be able to figure out how many hours of run time it takes before your product stops meeting spec. It’s easy to do and you just need to take the time to do it. Then change tips, hammers or hard surface screens or anvils and start the process over again.
Questions? Dave Whitelaw grinderguy@askthegrinderguy.com

Friday, April 1, 2016

Hey Grinderguy, what kind of questions do I ask when buying a windrow turner?

I gave a presentation at the USCC Conference in Jacksonville and was asked this question. Here are a few things you need to determine when sizing up Windrow Turners. Use them to relate to your situation:
·         How much material do you need to turn? Can you adjust your windrow size to be able to use a smaller turner? Why buy a 20’ Turner when a 16’ can turn the amount of material you need to turn? Most Turner specification sheets say they are able to turn 4000-6000 yards per hour. That’s a lot of material. So if you have the space, can you make smaller windrows and still turn what you need to turn?
·         Horsepower and Fuel Usage- See if smaller unit horsepower is sufficient to turn your material. The weight of Yard Waste is much less than the sludges or food wastes, so horsepower may not be an issue. The units running 600+ horsepower use a lot of fuel. Check fuel usage when you have demonstration.
·         Portability- If you need to move from site to site, make sure the unit doesn’t need to be taken apart or need permits that will limit your transportability
·         Drive System- Track or Wheels; try both for your situation. Check the cost of replacing wheels or track pads and links. Hydraulic driven drum or belt drive. Check the operational cost of both.
·         Automatic Control System- Can you let the machine maximize turning speed and load so the operator can concentrate on driving the unit?
·         Cab Features- Things like Charcoal Air Filtering keeps the operator cabin air clean. Bluetooth stereo with phone controls keeps the operators hands on the joysticks. Gauges easily visible limit any issues before they arise.
·         Safety- Ladders and platforms along with a ground entry cabin, helps operators and maintenance personnel work safely.
The main question to ask is the one to you. Can you make your material and site fit a particular size Windrow Turner and the cost of it?

Questions?         Dave Whitelaw                                 grindergu@askthegrinderguy.com

Tuesday, March 1, 2016

Hey Grinderguy, how do I start composting?

Making the switch from Grinding Service Vendor to Composter takes a little planning.
If you are an onsite grinding contractor or even if you currently have a mulch or soil yard and want to make the switch to full scale composting. What do you do? Most of the Mulch suppliers are quasi-composters. They pile up wood or bark Mulch and let it darken before they sell it. Well, THAT IS COMPOSTING!
So what are some points you should consider:
What are the Site needs? And do you currently have what is necessary?
·         What are you going to Compost? Yard Waste, Sludge, Food Waste
·         Type of Composting- Windrow, Static Pile,  Aerated Systems
·         Permitting- Depends on State
·         Space- Windrow, Piles
·         Water- YW mostly, Sludge and Food Wastes maybe not necessary
·         Leachate Collection
·         Contouring of Property for drainage
·         Additional Feedstocks- Mixing, Cover Material
Use these points and apply them to your current situation and see what you can achieve with what you currently have as a facility.

What additional Equipment needs are necessary?
·         Equipment Utilization is the Key
·         Can you use Subcontractors? Grinding, Screening
·         Do you need more Wheel Loaders? Moving Materials, Turning Screening, Etc.
·         Another Grinder? Or Subcontract
·         Windrow Turner- Number One Question? Do you need one?
·         Screen- Need to sell the product you create
·         Water Truck or Water Pumps- Water and oxygen equal composting
·         Compost Equipment- Temperature Probes, Testing Sieves
Do you have what is needed or do you need to purchase more equipment?

How do you change operationally?
·         Contracts- Need materials to compost and blend
·         Marketing- Have to find the customers
·         Screen Sizes- For screener and grinder
·         More Products- Soils, Potting Mixes
What can you use internally and what volumes do you need to sell?

What are the projected goals?
·         Increase Revenue? Diversify?
·         Exhaust Inventory? Eliminate current inventories?
·         Reduce/Eliminate Competition? If you don’t, someone will

If you have been a subcontractor grinding for others that may be in the business or a similar business, learn from your customers:
·         See what they do and how they do it
·         Note what you like
·         Note what you think is not working
·         Ask for Advice- There are others that have been in your situation

Dave Whitelaw “The Grinder Guy” www.askthegrinderguy.com

Sunday, February 7, 2016

Hey Grinder Guy, how do I control my traffic flow?

This is a common issue and safety is an issue with it also.
Anyone with a dump site needs a controlled traffic pattern with signage for your new customers. Your customer base that shows up daily knows where to dump and how things work because they are there regularly. But if you accept materials from the general public, they may show up on occasion and not know where or how to unload.  The general joke is that people are like sheep and follow what the previous one is doing. So if one person does the wrong thing, the others follow.
Here are a few ideas to use to keep a controlled pattern and to keep an efficient off-loading of materials:
·         Use as many signs and arrows as possible.
·         If you have the space, keep a separate area for commercial and public traffic. The general public off load by hand whereas most of the commercial vehicles are using a dump truck of some kind. The public vehicles will take more space and time moving around outside of the vehicles and get in the way of commercial traffic that can just dump and go.
·         Use a spotter or other employee to tell vehicles where to off load
·         Fill one area and move to the next while pushing and piling the off loaded materials from previous drop offs.
·         Any site operations should be on the opposite side of the pile being created with new material drop off. Grinding near the disposal area is an extreme safety concern. Everyone wants to see what the grinder is doing and will walk into unsafe areas not knowing any better.
·         Leave a large log or stump near the dump area. Vehicles, especially small landscapers, will pile material on a flatbed trailer and need to hand unload. If they have something heavy to tie off to, they can put a rope around the large stump and around some brush on the bottom of their trailer and just pull away and unload. Watch for vehicles running in reverse and hitting the brakes to unload, this is more than unsafe and you are within your legal rights to bar them from the property if they do not adhere to the rules of the site.
What about using the drop off vehicles to assist in site operations?
·         Pile new materials in windrows and grind next to them to create ground material windrows and keep moving to the next windrow as they are created.
·         Dump in the center of the site and pile ground materials on either side and keep the windrows moving away from the center as you turn and compost them.
·         Separate materials as they are dumped. Have the spotter look at each load and direct traffic to the appropriate pile. This saves on grinding and separating materials with equipment later. It’s easy to keep chip and logs separate for use in mulch later for example.
I’ve given you several things to consider but the most essential and safe things to do regardless of your site size and disposal numbers are:
·         Use Signs or Arrows
·         Use a spotter
·         Keep equipment away from incoming traffic
Hope this helps.
Questions?

Dave Whitelaw Grinderguy@askthegrinderguy.com