problem in two roll mills

In a previous paper consideration was given to the flow of a generalised Newtonian liquid between contra-rotating cylinders — the so-called two-roll mill problem. We present here an extension to that work in which we consider the effect of elasticity on the flow. An Oldroyd three-constant model is used to characterize the fluid properties and a finite-element method used to solve the ...

2 Roller Mill Maintenance ... clean #2 corn is processed, roll corrugation intervals will be extended ... the associated maintenance and operational problems. Roller mills are also more sensitive to instantaneous changes in the feed rate than are other pieces of process equipment. Feeding a roller mill directly from a screw conveyor or bucket

2. Three-High Rolling Mills: In this mill, the three rolls stand in parallel one by others. The rolls are rotating in opposite directions. In this mill, between the first and the second rolls, the material passes. If the second roll rotates in a direction then the bottom roll rotates in another direction.

•To determine what problems (if any) existed with the drive, a comparison of the route vibration data between 1A & 1B Ball Mills was made as well as between loaded & unloaded data at 1A Ball Mill. •Table 2 below shows the symbols & descriptions of each measurement point taken.

Nov 27, 2015 The final dimensional quality of the rolled product is determined by the rolling stands within the finishing mill. The dimensional accuracy in the final product depends on many factors including the initial stock dimensions, roll pass sequence, temperature, microstructure, roll surface quality, roll and stand stiffness and the stock/roll friction condition.

finishing mills, which will roll the steel in tandem with one another. The workhorse roughing mill has 135” wide rolls for rolling ‘broadside’ (as the first roughing mill is commonly called) to make a slab wider. A 5,000 hp motor drives 42”-diameter work-rolls through 28:1 gears to reduce the slab’s thickness by as much as 2 …

A typical layout of a mill using the kraft chemical pulping process is shown in figure 2-1. Mechanical, semichemical, and sulfite pulp mills differ in detail, particularly in wood preparation, fiber separation, and bleaching, but many of the downstream refining, bleaching, and papermaking processes are similar.

Roller mills simply “roll” or “crush” product between two revolving cylinders. This latter process has the distinct advantage of requiring considerably less power, although it is not possible to achieve the fineness of final grind through a roller mill that can be achieved through a hammermill.

Aug 26, 2014 Cantilever mill roll Tube mill roll Universal roll Suranaree University of Technology Tapany Udomphol Jan-Mar 2007 9. Typical arrangement of rollers for rolling mills Two-high mill, pullover The stock is returned to the entrance for further reduction.

The three high rolling mill utilizes the principle of passing the work back and forth to achieve a series of reductions. Unlike the two high reversing mill, the three high mill has three rolls that always spin in the same direction. An elevator mechanism lifts and lowers the work so that it can be passed back and forth through the rolls.

The rolling process is shown in Fig. 2.1: Rolling is done both hot and cold. It is accomplishes in rolling mills. A rolling mill is a complex machine having two or more working rollers, supporting rollers, roll stands, drive motor, reducing gear, flywheel, coupling gear etc. Rollers may be plain or grooved depends upon the shape of rolled product.

Jul 02, 2014 2.15 Special consideration 2.15.1 Applicability Universal joints are particularly well suited for the angularity requirements of reversing rougher mill applications. The rolls of these mills are usually powered by two separate direct drive motors that are speed synchronized by the mill control system.

Jan 01, 1986 In previous papers [1,2] we considered the numerical simulation of the flow of generalised Newtonian and visco-elastic liquids between contra-rotating cylinders—the so-called two-roll mill problem. In the latter case, an Oldroyd three-constant model was used to characterize the fluid properties.

established industry safeguarding standards for two-roll mills, internal mixers and calenders. Many serious accidents take place during repairs or to clear blockages etc. and there must be...

Aug 16, 2001 A good maintenance program, as well as rebuilds or upgrades when necessary, is essential. 6. Mill in misalignment. Tube mill misalignment, poor mill condition, and inaccurate setup account for 95 percent of all problems in tube production. Most mills should be aligned at least once a year. 7. Tooling in poor condition.

2.2.1 Two Roll Mill The two roll mill in Fig. 2.1 consists of two horizontal, parallel, heavy metal rolls which can be jacketed with steam and water to control temperature. These rolls turn towards each other with a pre-set, adjustable gap or nip to allow the rubber to pass through to achieve high-shear mixing. The back roll usually turns at a ...

Feb 27, 2003 A quick check with a straight edge on the roll form tooling can indicate a problem with machine face alignment. Many times a quick check with a straight edge on the tooling can tell you if there is a problem (see Figure 1 ). If you find a problem, you must remove the …

Aug 01, 2006 Bagging on a two roll mill is the inability of a rubber stock to form a rolling bank at the mill nip, sagging off the rolls and exhibiting little or no adhesion to the rolls (ref. 72).

The mill supplies paper rolls or “final rolls” to customers that are cut from several master rolls of different widths. The width of a master roll defines a master roll type. The need is to generate a master roll cutting plan that minimizes the cost of cutting and procuring master rolls consumed to satisfy all the demands of the final rolls.

Problem 2: A reversing mill is a two-high rolling mill in which the direction of rotation of the rolls can be reversed to allow the work to pass through from either side. A series of cold rolling operations are to be used to reduce the thickness of a metal plate from 50 mm to 20 mm in a reversing mill. Roll diameter = 600 mm, and coefficient of ...

Tandem cold rolling mills can be basically split into two groups; sheet mills if they reduce hot band to sheet gauge or tin mills if they roll the same incoming material to tinplate stock. Key advantages of the tandem rolling process include cost reduction and good improvements in productivity especially when integrated with a continuous ...

Roll Press Briquetting and Pelleting of Corn Stover and Switchgrass, Problem Statement (Densification of biomass material is a great way to solve rising problems and efficiently use biomass material. Role press briquetting and pelleting are densification method used to produce biomass material in form of pellets and briquettes. The question here is that between both methods of densification ...