1. Raymond Mill Development History
Raymond mill is also called Raymond grinding mill, English Name: Raymond mill . It is
suitable for various powder preparation, coal preparation, such as powder processing of raw
ore, gypsum ore, coal and other materials.
In 1906 C.V.Grueber created Curt Von Grueber machinery manufacturing factory in the south
of Berlin City, using him to USA patents granted to produce the first Maxecon grinding, and
used in Berlin area BEWAG MOABIT power plant as a coal grinding equipment, grinding
energy is 5T/H, within a few years, selling nearly 600 units, were applied to the grinding area
in different industries. The same BEWAG to build coal mill output higher.
E.C.Loesche and Curt Von Grueber in charge of machinery manufacturing plant after the
decision to buy Raymond centrifugal ring roll USA open mill patents, produced the first
generation of Raymond Mill system. The structure is in the machine center stands with a
rotating spindle plum frame, plum frame hang 3 or more of the rotation roller, the rotating
shaft to drive the rotating roller swing outwards, and driving under the centrifugal force
pressure to the embedded in the inner wall of the mill ring. Material guide vane in the plough
shaped roller below the material into the grinding zone under the action of the rollers of belt.
The grinding force coal grinding roller of Raymond Mill (centrifugal force) by grinding roller
diameter and speed limits, the mill was applied to soft, low ash and grindability of coal
material good, while Germany is much harder, ash content and high, need the milling force is
higher, this structure thunder Mongolia coal mill is difficult to meet the requirements of
Raymond mill grinding, it gained popularity not in germany. At that time, Raymond mill is
suitable for grinding American coal quality requirements, so Ramon coal mill was America
widely spreaded and applied.
In 1925, E.C.Loesche summarizes the characteristics and structure of the first generation of
Raymond Mill malpractice, decided to further improve grinding structure of Raymond mill,
developed a grinding principle and the opposite mill, called the improved Raymond mill. The
main structure is characterized in that the grinding ring rotary bowl, roll grinding by
mechanical spring load pressure increase grinding force, material from the center feeding
bowl mill ring by a rotating centrifugal force into the grinding roller. Grinding roller shaft is
fixed on the rocker arm a one-way activity, spring to control the grinding force of each arm is
adjustable. The improved Raymond Mill System of ventilation with positive and negative
pressure blowing straight in two ways. This type of Raymond Mill patent was soon USA
Combustion Engineering Company (Combustion Engineering) purchased.
Because the improved Raymond mill still ring roll mill, although the roll diameter increases
slightly, but the grinding force increases slightly. Later, America Combustion Engineering
Raymond branch and then developed a new generation of Raymond mill, known as the VR
mill. The Raymond mill structure in many aspects and Loesche mill are similar. It remarkably
different from Loesche mill cone grinding roller and the plane grinding, and the use of
cylindrical grinding roller and belt grinding surface tilt angle of 15 degrees of disc. The
grinding roller with Loesche mill grinding roller out device similar in inspection and repair,

2. and is also provided with a protection device, in order to prevent metal to metal contact
between the grinding roller and the grinding disc.
Also in the mill grinding roller can advance before starting up, this can reduce the starting
torque of the motor. Raymond Mill in American industrial applications, usually used in the
preparation of pulverized coal, the fineness of product changes in the 250-325 mesh, can be
adjusted work product fineness and yield during operation.
Raymond Mill: http://www.sbmcrush.com/products/grinding/raymond-mill.html