vertical mill process flow

vertimill - metso outotec

vertimill - metso outotec

Vertimill is a unique product offered exclusively by Metso Outotec. Grinding efficiency, reduced media consumption, lower installation cost, minimal maintenance, and minimal liner wear make Vertimill the lowest total cost of ownership in many applications, substantially improving the profitability of concentrators.

Mechanically, Vertimill is a simple machine with an agitating screw suspended into the grinding chamber, supported by spherical roller bearings and driven by a fixed speed motor through a planetary gearbox.

Vertimill is an energy efficient grinding machine. They tend to grind more efficiently than, for example, ball mills with feeds as coarse as 6 mm to products finer than 20 microns. This provides up to a 40% higher energy efficiency.

As the particles are ground, they rise to the top of the mill and overflow into the separating tank. A change in the rotational direction of the slurry when it transitions from the mill to the separating tank causes turbulence which facilitates a settling of the coarser material.

The recycle system can reduce cyclone circulating load by allowing the mill to preferentially grind the coarser material. Also, the uprising velocity in the mill can be controlled by a recycle pump to affect the product size distribution, prevent over grinding, and reduce the circulating load from the cyclone.

Final product size is a factor of applied grinding power, flow rate, and slurry density. The effective operation of the Vertimill requires these parameters to be accurately and constantly monitored and adjusted to meet the required product specifications.

characteristics and process flow of vertical roller mill for titanium gypsum powder

characteristics and process flow of vertical roller mill for titanium gypsum powder

What grinding mill equipment is a common special grinding mill in the field of solid waste residue? The manufacturer HCMilling(Guilin Hongcheng)provides exclusive vertical roller millequipment to meet the production demand of titanium gypsum, steel slag, water slag, slag and other solid wastes into treasure, and provides strong equipment support and technical support for actively exploring the recycling road of titanium gypsum grinding and other solid wastes.

Solid waste residue is the waste produced in the process of industrial construction, and its recycling value is high. In view of the development demand of solid waste recycling, HCMilling(Guilin Hongcheng)continues to provide advanced environmental protection grinding mill equipment, and create value for solid waste residue. Vertical roller mill is a special equipment to meet the needs of solid waste slag milling, and also has a wealth of customer cases. According to different requirements, HCMcan provide special vertical mill model and grinding production line scheme.

Vertical roller mill is a large-scale production increasing equipment integrating crushing, grinding, grading, drying and powder collection. It can be used in many grinding fields such as coal mine, non-metallic ore, slag, cement industry, thermal power plant and so on. It is an advanced equipment to solve the problems of low productivity and high energy consumption of industrial mill.

The process flow is simple, the system equipment is few, the structure layout is compact, the floor area is small, which is 50% of the ball mill. It can be arranged in the open air with low construction cost and directly reduces the investment cost of enterprises.

The technological process of special vertical mill is mainly composed of crushing, grinding, grading and powder collecting. To provide customers with a customized solution and create value for each customer.

The material enters the grinding roller table and is squeezed, ground and sheared. After grinding, the material is blown up by high-speed airflow, and the coarse-grained material is blown back to the grinding plate for regrinding, and the suspended material can be dried at the same time.

For titanium gypsumgrinding, water slag, steel slag and other solid waste slag, the use of professional vertical roller mill equipment is an ideal grinding processing equipment, which can help to realize the comprehensive utilization value of solid waste slag and create greater market value.Please contact:

Simply complete the form below, click submit, you will get the price list and a Hongcheng representative will contact you within one business day. Please also feel free to contact us by email or phone. ( * Denotes a required field).

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cnc milling - a complete guide to understand the process

cnc milling - a complete guide to understand the process

CNC milling is one of the most common processes when looking to produce complex parts. Why complex? Whenever other fabrication methods like laser or plasma cutting can get the same results, it is cheaper to go with them. But these two do not provide anything similar to the capabilities of CNC milling.

So, we are going to take a deep dive into milling, looking at the various aspects of the process itself as well as the machinery. This will help you understand if you require CNC milling services to produce your parts or is there a more cost-effective alternative available.

We are going to look at the process, machinery, etc. in later paragraphs. But lets first make clear what CNC milling means and bring clarity to some of the more confusing points about the term itself.

First, people often ask for CNC machining when looking for milling. Machining entails both milling and turning but these two have distinct differences. Machining refers to a mechanical cutting technology that uses physical contact to remove material, using a wide range of tools.

Secondly, all CNC machining uses CNC machines but not all CNC machines are for machining. Computer numerical control is what lies behind these three letters. Any machine using CNC utilises computerised systems for automating the cutting process.

So CNC machining is a mix of these two terms, bringing us the answer to the question posed in the heading. CNC milling is a substractive fabrication method that uses computer numerical controls systems for automating the process.

G code can also be written manually, as was done in the past. This, however, prolongs the whole process considerably. Therefore, we would suggest making full use of the possibilities modern engineering software offers.

Although CNC machines do the cutting work automatically, many other aspects of the process need a machine operators hand. For example, fixing the workpiece to the worktable as well as attaching the milling tools to the spindle of the machine.

Manual milling depends heavily on the operators while newer models have more advanced automation systems. Modern milling centres may also have live tooling possibilities. This means they can change the tools on the go during the manufacturing process. So there are fewer stops but someone still has to set them up beforehand.

The milling process usually comprises of a few different operations but this depends on the shape of the final product and the state of the raw piece. Often, milling is necessary for giving a precise finish and adding a few features like slots or threaded holes.

But it is also suitable for creating a finished part from a block of material. The first operations use larger tools to quickly carve away the material to fasten the process until getting to an approximate shape of the final piece.

A tool change is necessary to create the highly accurate machined parts. The great precision milling is known for is achieved in the last stage, taking engineering tolerances and surface roughness to levels hard to match with any other fabrication process.

Now, lets see what makes up a milling machine. While new milling centres have the capabilities to perform all kinds of operations, they are also more complicated. So we are sticking to the more traditional benches here to give an overview of the machine components.

Horizontal milling machines derive their name from the positioning of the tool their axis lies horizontally. The images above show one way of using them which is plain milling. Of course, horizontal mills are also suitable for end milling.

Of course, newer machines look a little different, making them suitable for automation. Horizontal milling centres may have several spindles with a variety of tools on them for quicker turnaround times. Also, the table as well as the tools can move in more directions, including rotational axes.

There are a few differences between horizontal and vertical milling machines. But the main components are still similar. The machine head is at the end of a ram. The spindle for cutting tools is attached to the head.

The modern 5-axis vertical mills offer possibilities to rotate the part for more access and faster turnaround times. Automating all the movements results in better accuracy, quicker lead times and close to identical batches of parts.

There is a lot of variety available on the market today. Numerous ways of classification also exist. The basics remain pretty much the same everywhere, with a few modifications bringing about more possibilities and hence another type of milling machine.

The design of bed-type milling machines includes a stable machine bed. While large and heavy parts can result in instability with knee-type machines, bed-type ones can hold their ground. The long bed means that multiple parts can be attached onto the bed at once, diminishing idle times and increasing the efficiency on the workfloor.

The worktable attaches directly to the bed of the machine and can move in 2 directions. The spindle head, of course, can move axially to determine the cut depth. The position of the axis depends on the machine, as there are both horizontal and vertical bed mills, as well as universal machines. All of them can also be automated by using CNC.

Another way to increase productivity is using a two-machine stand. This helps to either mount a number of parts onto the table for simultaneous processing or one large part. This loses the necessity for re-clamping it to process the other end. It is important to note that this setup opens the possibility to tool collision which can be prevented by a correct CNC program.

These machines are suitable for producing parts ranging from small to medium size. The limitation comes from the fact that knee-type mills provide less stability than, for example, bed-type milling machines. Also, the frame sets its own limits for part dimensions.

A traditional knee-type mill is a great option for producing one-off parts, maintenance work, preparatory tasks, etc. The unidirectional movement of the cutting head limits the possibility of accidents. Using them for preparing the workpiece for later refining on a CNC station is common.

These machines require a manual change of tools after every operation, making the whole process a little slower. Still, modern CNC machining centres include the capabilities of knee-type milling machines.

The ram-type mill has its cutting head mounted on a ram that can slide back-and-forth. This increases the tool movement to 2 axes X and Y. Both horizontal and vertical options of the ram mill are available on the market. Many of such mills also include the ability for swivelling the cutting head.

Planer-type mills are very similar to bed-type milling machines. Both have large worktables and spindles that can move in 3 directions. The main difference comes from the planer-type milling machines ability to accommodate more milling tools at once. The number of different tools usually goes up to 4.

A 3-axis vertical mill means that the table can move in 2 directions X and Y. This enables positioning the workpiece relative to the cutting tool while the distance remains the same. So the third, Z-axis, is added by allowing to lower the cutting tool.

A 4-axis mill has all the 3 axes as previously described. But another one comes in the A-axis. Now the table can rotate around the X-axis, allowing face milling the sides without repositioning of the workpiece.

5-axis CNC machining centres cost a lot more than the other options but make it possible to produce very complex parts in one go. No extra setups are necessary while the tool life increases through making the suitable part positioning possible.

6-axis CNC milling centres are not too common because of the hefty price-tag. They can be up to 75% quicker than 5-axis machines but the necessity of such capabilities is rare enough to justify the expenses. The video above also shows a comparison of a 5-axis and 6-axis mill.

Milling is suitable for many different features, including threading, chamfering, slotting, etc. This allows for producing complex designs on a single CNC milling centre with enviable accuracy. The tolerances for CNC machining are around +/- 0.1 mm.

Surface milling can use different cutters, wide or narrow, depending on the necessary outcome. Using a wide cutter can result in fast material removal when coupled with slow cutting speed, fast feed rate and coarse teeth of the cutter. Of course, the surface finish of such cutting may not meet the requirements.

Therefore, a second step can include a change of tools to use finer teeth. This also requires faster cutting speeds and slower feed rates, so the amount of material removal per time unit is slower. At the same time, the final finish is more accurate. Thus, the combination of the two makes for a good choice from an economic standpoint.

Face milling often comes after surface milling, as it can produce more intricate contours and leaves a nice finish. The teeth on the sides do most of the cutting work while the teeth on the tip take care of the surface finish.

In case of a regular 3-axis mill, the use of different cutters makes the most sense. These can be dovetail cutters to produce angled grooves or just a mill with a conical cutting head for chamfering. Note that these two are basically the opposites of each other.

Form milling helps to create these surface contours in a single cut. The tools can help create round recesses, round edges, etc. The tools must have the right parameters to achieve the desired outcome.

First comes gear milling. The material softness enables creating the part with more ease while achieving great tolerances. The gears then go through a heat treatment process to harden the surface. After that, CNC turning will be responsible for the final outcome.

effects of rotation speed and outlet opening on particle flow in a vertical rice mill - sciencedirect

effects of rotation speed and outlet opening on particle flow in a vertical rice mill - sciencedirect

Flow behaviors of rice particles in a vertical mill are investigated.Outlet opening and rotation speed of mill influence milling properties.Milling of particles occurs mainly in the top half of milling chamber.Spatial distribution of collision energy can express the wear of rice particles.The relation between collision energy and operating parameters is established.

Rice mill is the key equipment to food processing used for milling unpolished rice to milled rice. However, there are few investigations about the flow process on rice particles inside the mill and the role of operation parameters. In addition, the detailed information about particle interaction and mechanisms of milling remains poorly understood. This paper presents a numerical study based on the discrete element method (DEM) to investigate the flow of rice particles in a vertical rice mill. The effects of operation parameters on the hidden flow properties, including particle orientation angle, particle fill level, collision energy and energy efficiency, were analyzed. The results showed that the particle orientations prefer pointing to 0 and 180 and orientation angles fluctuate at U-shaped distributions on a vertical plane. The wear process of particles can be described by the spatial distribution of collision energy. Wear of particles occurs mainly in the upper half of milling chamber, in which is defined as milling area. The effects of outlet opening on flow structure and particle fill level in milling area are more obvious, compared with that of the rotation speed. However, the increase of rotation speed results in higher collision energy, collision number and energy efficiency, which accelerates wear of rice particles. The findings are useful to understand particle flow, wear and milling behavior of the vertical rice mill.

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