Terex Jaw Plate Selection

Terex Jaw Plate Selection

Tips to Help Keep You Crusher Up and Running In Winter

There is no such thing as bad weather, however, there is such a thing as inappropriate clothing. Crushing in the winter is tougher but doesn’t have to be miserable with some planning and solid thinking.

Here are a few tips for getting your spread ready for winter crushing:

CONVEYORS

Although low temperatures rarely have a harmful effect on rubber compounds, stiffening of the belt may cause tracing problems until it warms up. This mostly applies to belts containing neoprene compounds. Before these belts will train properly, they must be warmed to a temperature above freezing.

Frost, snow and ice can also hinder proper belt performance by causing load slippage. Ice buildup on the troughed side of the belt can plug the chutes, and ice can form on the conveyor hardware and cause more damage than just material buildup.

A recommended method for “de-icing” or removing cold weather glazing is to use ethylene glycol. Calcium chloride solutions are also sometimes used, but they can corrode conveyor parts.

Ideally, ice buildup should be removed before the conveyor is started. If the system must be kept ice-free at all times, the hopper should be covered and heated if possible.

The general effects of cold on conveyor systems are: increased power demands during startup, freezing up of rotating mechanical parts and causing drive motors to stall.

An option when running a conveyor in extremely cold conditions is to never shut the conveyor down. This can be done by either running the belt at full speed or by using a creeper drive on the system.

A concern for operators is when temperatures hover around freezing – melting and freezing can occur in these conditions causes wet or sticky material to adhere to screens and conveyors throughout the day. That material will then freeze into place overnight and create problems the next day.  Operators have some very effective tools at their disposal to address these kinds of problems.

SELF-CLEANING SCREEN MEDIA

For screening, engineered self-clean media is now available to keep blinding to a minimum and provide effective dry separation of fine sizes, even in marginal weather conditions.

BELTS AND BELT SCRAPERS

Keeping conveyor belts clean and moving is the primary challenge in the winter. There is a wide range of belt scrapers and brushes available which can keep belts clean and moving. An important consideration for portable plants is that conveyor tail pulleys are mounted low to the ground. This means the belt must be kept clean to prevent material from collecting on the underside of the belt which can mis-track the belt or harm pulley bearings. If maintained properly, belt scrapers can eliminate a lot of conveyor build-up problems. Always ensure skirting rubber and plow scraper are not frozen to the belt before starting the conveyor. Also, make sure you switch to using synthetic oil in the gearboxes for your conveyors.

BELT HEATERS

There are several varieties, sizes and models of conveyor belt heaters which have been developed for severe cold and winter conditions. Some are designed specifically to apply the right amount of heat to areas where ice buildup occurs, such as drive rolls, bend pulleys and idlers. The unit is placed close to the driver roll or bend pulley in order to heat and dry the bell as well as the roll. This goes a long way to reducing or eliminating ice accumulation where it is most likely to occur.

Another benefit of using belt heaters is they de-ice the belt and prevent material slide back and problems with the belt scrapers.  Eliminating ice on a drive roll to prevent drive roll slippage can also eliminate the need for increased belt tension, meaning there will be less belt wear and less horsepower required.

CONES & JAWS

If you are shutting down the plant for a night or a weekend, it is a good idea to cover the jaw or cone with a tarp to keep snow from accumulating on it. You also need to switch to synthetic oil for cones, and change grease everywhere from EP1 to EP2 which has a lower freezing point. If you can, run two shifts a day instead of one to keep everything warm and moving.

CRITICAL HYDRAULIC LINES

Wrap in Heat Tape.  Pay special attention to your cone accumulator line.

WINTER EFFICIENCY

One of the few advantages of winter operating is improved screening efficiency, provided the weather stays cold and clear. In sub-zero temperatures, there is no free water available to bind particles together, allowing fine sized particles (including piggyback fines on larger material) to more easily separate from larger particles. The result is improvement screen output and finished product cleanliness.

Successful winter crushing demands the right maintenance processes and accessories.

For more information about getting ready for winter, contact us!

TIC Insert Jaw Crusher Liners

TIC Insert Jaw Crusher Liners

Impact crusher blow bars easily break reasons analysis

Impact crusher blow bars easily break reasons analysis

There are many reasons why your impact crusher blow bars are breaking on a regular basis. We have compiled a list of the most common causes of blow bar failure and the solutions to those problems.

1.Blow Bar Not Seating Against Rotor

Notice the gap shown by the left arrow. The blow bar is supposed to be flush with this surface, driven by a wedge. The direction is shown by the right arrow.

Blow Bar Not Seating Against Rotor

Possible Causes:

  • The rotor is not straight or needs to be rebuilt.
  • Blow bar is not straight, defective, or not properly machined to specs.
  • Blow bar could be pivoting, rocking on the locking mechanism, or there may be a fitting issue.

2.Worn and Cracked Rotor

This customer experienced multiple breakages at the point where the rotor was worn and had a crack. This rotor needs to be replaced or rebuilt.

Worn and Cracked Rotor

If a replacement or rebuild is not practical, moving to Manganese blow bars will help.

3. Loose Wedges

Problem:
The customer was experiencing breakage. When we went to the site, we found that the wedges were loose, causing the bar to move up in the rotor station, causing pressure on the locating nose. This pressure lead to a break in a blow bar. A new person was in charge of the crusher and did not realize they could loosen.

Loose Impact Crusher Wedges

Solution:
A program was initiated to check wedge tightness a few hours after new blow bars were installed and at other intervals.

4. Lack of Blow Bar Support

Are the wedges tightened properly? What is the condition of the wedges?
Are they being checked periodically for tightness, especially after initial installation?

Image 1 & 2
Here is an example of wedges not being used properly; the user was forcing old nuts/bolts under wedges to push them up instead of jacking bolts/ set screws. These wedges need to be replaced with new ones!

Lack of Blow Bar SupportLack of Blow Bar Support

Image 3
Another example of breakage due to the insufficient support of the blow bar. Notice how the wedge & rotor is worn down, so it only contacts the bar properly at the bottom.

Lack of Blow Bar Support

 

When to change cone crusher liners

When to change cone crusher liners?

There is an optimum time to change your cone liners. Too soon and you don’t get the value for the cost of the liner, too late and you suffer from significant production losses.

It is our experience that too many people lean towards too late, the optimum time to change a liner really depends on how much money you are prepared to lose to production losses to get the maximum use out of a wear component.

The first condition that is optimum is that the liner change happens when you planned it. This gives you the opportunity to have all of the required parts on-hand before starting. This also allows you to perform other maintenance work on other equipment when the change is being conducted. These days it’s tough to get screen media and manganese on a moment’s notice and you will need to plan things if you need to rent a crane.

The second condition is changing the liner before you start to suffer significant production losses. On top adjust/screw adjust cones this is especially true as the feed size starts to shrink pretty dramatically as soon as you get to the last 1/3 of life and as you near the end the feed size can get very small, losing as much 30% of feed size. This is less of an issue with hydrocodones as the feed size remains constant throughout the life of the manganese.

Having certain materials available at the processing plant can minimize equipment downtime when replacing the wear liners. These materials include:

  • A) Mantle – also known as headliner.
  • B) Cutting ring – the cutting ring is not reusable, so a new ring should be installed every time the mantle is replaced.
  • C) Bowl liner
  • D) Padding material – its purpose is to cushion (shock absorption), not to fasten the liners. Lubrication of the head/bowl is recommended to facilitate subsequent replacement.
  • E) Cone feed plate – also known as the feed cone; it should be replaced every time the mantle is replaced.
  • F) Hex (hexagonal) head bolt – replace only if necessary.
  • G) Mantle locking bolt – replacement of this bolt is not necessary with every replacement of the mantle, but a new locking bolt should be kept on hand at the worksite just in case it needs to be replaced.
  • H) Set of square-head bolts – replacement of this/these bolt(s) is not necessary with every replacement of lining materials, but it is important to always have a set available at the worksite.

Other wear parts that should be inspected whenever liners are replaced:

  • Main frame liner
  • Counterweight liner
  • Countershaft guard
  • Frame arm guard

For additional details regarding the replacement of the mantle and bowl liner, please refer to your equipment’s instruction manual.

When to change jaw plate

When to change jaw plate?

The ideal situation would be when even wear occurs throughout the jaw plate area, using all the manganese teeth, eliminating the need to execute the “turn”, or change production.

This is impossible, however, because there are areas where we cannot avoid more severe wear than in others, mainly because of the crushing movement geometry, such as in the fixed jaw plate lower tip and the central area of the swing jaw plate, so a turn should be carried out to achieve better performance and use. We recommend a double turn, in other words:

Fixed jaw plate – use until wear of about 50% occurs in the lower area and make the first turn. Make the second turn when wear from 90% to 100% occurs in this new lower area. Conclude using the remaining 50% of the life cycle of this extremity.

When to change jaw plate?

From left to right: initial (50%), first turn (90-100%) and second turn (final).

Swing jaw plate – the same procedure is applied to the swing jaw plate because although the wear occurs in the central area, it rarely occurs in the exact middle of the jaw plate.

MGS Crusher Parts standard jaw plates offer an extensive range of different designs and material selections in order to suit your application. Our wide range allows you to select the right jaw plates based on feed material and required end materials, leading to better crusher and cost efficiency, as well as high productivity.