First Generation of Raymond Mill
In 1906, C.V. Grueber founded a machinery factory in the southern suburbs of Berlin. Using his patents obtained in the United States, he produced the first Maxecon mill and used it as the coal grinding equipment for the MOABIT power station. The grinding power can reach 5TPH. In the past few years, nearly 600 units have been sold and used in different industries. In the same period, BEWAG planned to develop a coal mill with a higher output. After E.C. Loesche took over and headed the C.V. Grueber Machinery Plant, he decided to purchase the patented Raymond Centrifugal Ring-roller Mill from the United States to produce the first generation of Raymond Mill system.
However, practices proved that the fineness of finished products produced by Raymond Mills was dissatisfactory. Usually, the fineness was about 400 meshes, with very little material’s fineness up to 1000 meshes, which did not meet the requirements of refined development. This kind of Raymond mill was only suitable coal materials with soft, low ash and good grinding property, because the grinding force (centrifugal force) of Raymond coal grinding mill was limited by the diameter and rotation speed of grinding roller at that time. However, German coal was characteristic of hard and high ash content, which required higher grinding power. Therefore, Raymond mill of this structure wasn’t prevalent in Germany as itwas difficult to meet the grinding requirements. But it was surprising that this kind of Raymond mill was just suitable for the coal quality in the United States, there was no doubt that Raymond mill was widely promoted and applied in the United States.
Who Improved Raymond Mill?
In 1925,E.C.Loesche summarized the use characteristics and disadvantages of the first generation of Raymond coal mill and decided to further improve the structure of Raymond mill. He developed a mill whose grinding principle is opposite to the first one, which was called improved Raymond mill.
The ventilation of this improved Raymond mill system has two modes: positive pressure and negative pressure direct blowing. The patent of this type of Raymond mill was soon acquired by Combustion Engineering (a company in America).
The Raymond mill upgraded were still problems on its roller so far. Although the roller diameter increased slightly, it didn’t work very well.
Later, Combustion Engineering developed a new generation of Raymond mill on the ground, which named VR mill.
The structure of this Raymond mill was similar in many aspects to that of the current Loesche mill. However, it was different from Loesche mill on its cylindrical grinding roller and grinder table with a 15 degree sloping surface. The grinding roller was equipped with a roll-out device for inspection and maintenance. And it also equipped a protective device to prevent metal contact between the grinding roller and the grinding table. In addition, the grinding roller can be lifted in advance before the mill starts that can reduce the pull-in torque.
Raymond mills were usually used to make pulverized coal in the United States. The fineness of finished product varies between 250-325 mesh (fineness and output can be adjusted during operation).
Since Raymond Mill was patented, it has been more than fifty years. With years of development and improvement, more and more types and models of Raymond mill are developed with stable performance, strong adaptability and cost-effective performance.
Upgraded Raymond Mills Launched by SBM
SBM has launched three upgrade series of Raymond Mills, MB5X Pendulum Roller Mill, MTW European Grinding Mill and MTM Medium-speed Grinding Mill respectively. Compared with the first generation of Raymond Mills, these three types of grinding mills are more energy-efficient and environmentally friendly, have more sophisticated automatic control systems, and can help users to move toward refined and large-scale development.
In 1906, C.V. Grueber founded a machinery factory in the southern suburbs of Berlin. Using his patents obtained in the United States, he produced the first Maxecon mill and used it as the coal grinding equipment for the MOABIT power station. The grinding power can reach 5TPH. In the past few years, nearly 600 units have been sold and used in different industries. In the same period, BEWAG planned to develop a coal mill with a higher output. After E.C. Loesche took over and headed the C.V. Grueber Machinery Plant, he decided to purchase the patented Raymond Centrifugal Ring-roller Mill from the United States to produce the first generation of Raymond Mill system.
However, practices proved that the fineness of finished products produced by Raymond Mills was dissatisfactory. Usually, the fineness was about 400 meshes, with very little material’s fineness up to 1000 meshes, which did not meet the requirements of refined development. This kind of Raymond mill was only suitable coal materials with soft, low ash and good grinding property, because the grinding force (centrifugal force) of Raymond coal grinding mill was limited by the diameter and rotation speed of grinding roller at that time. However, German coal was characteristic of hard and high ash content, which required higher grinding power. Therefore, Raymond mill of this structure wasn’t prevalent in Germany as itwas difficult to meet the grinding requirements. But it was surprising that this kind of Raymond mill was just suitable for the coal quality in the United States, there was no doubt that Raymond mill was widely promoted and applied in the United States.
Who Improved Raymond Mill?
In 1925,E.C.Loesche summarized the use characteristics and disadvantages of the first generation of Raymond coal mill and decided to further improve the structure of Raymond mill. He developed a mill whose grinding principle is opposite to the first one, which was called improved Raymond mill.
The ventilation of this improved Raymond mill system has two modes: positive pressure and negative pressure direct blowing. The patent of this type of Raymond mill was soon acquired by Combustion Engineering (a company in America).
The Raymond mill upgraded were still problems on its roller so far. Although the roller diameter increased slightly, it didn’t work very well.
Later, Combustion Engineering developed a new generation of Raymond mill on the ground, which named VR mill.
The structure of this Raymond mill was similar in many aspects to that of the current Loesche mill. However, it was different from Loesche mill on its cylindrical grinding roller and grinder table with a 15 degree sloping surface. The grinding roller was equipped with a roll-out device for inspection and maintenance. And it also equipped a protective device to prevent metal contact between the grinding roller and the grinding table. In addition, the grinding roller can be lifted in advance before the mill starts that can reduce the pull-in torque.
Raymond mills were usually used to make pulverized coal in the United States. The fineness of finished product varies between 250-325 mesh (fineness and output can be adjusted during operation).
Since Raymond Mill was patented, it has been more than fifty years. With years of development and improvement, more and more types and models of Raymond mill are developed with stable performance, strong adaptability and cost-effective performance.
Upgraded Raymond Mills Launched by SBM
SBM has launched three upgrade series of Raymond Mills, MB5X Pendulum Roller Mill, MTW European Grinding Mill and MTM Medium-speed Grinding Mill respectively. Compared with the first generation of Raymond Mills, these three types of grinding mills are more energy-efficient and environmentally friendly, have more sophisticated automatic control systems, and can help users to move toward refined and large-scale development.
