F. L. Smidth & Co.

A Gramkow A/s

Hans B Knudsen

Asger Gramkow

Rolf Dietrich Houd

Louis B Cording

In systems or units for collecting volatile liquids, e.g. refrigerants from scrapped refrigeration systems, the liquid may be successively filled into a closed collector tank, inasfar as the vapor of the liquid as collected in the upper space of the tank will be condensed into the liquid as this rises in the tank. However, there will be separated also an amount of non-condensible gas, e.g. atmospheric air, that will cause a steadily increasing pressure in the tank, so that it is necessary to regularly effect a venting of the tank, that is a gas blow-off, by suitably controlling an upper blow-off valve on the tank. All according to the temperature such a blow-off, however, may be connected with a more or less pronounced and undesirable blow-off of the condensible gas, and the blow-off is minimized by a blow-off valve being controlled from a differential pressostat, which is influenced partly by the actual pressure in the collector tank and partly by the vapor pressure of from a confined volume of the liquid in its pure state. Thereby, the pressure contribution from the condensible gas in the tank, no matter the temperature, is compensated for, and thereby a more favorable controlling of the blow-off for minimizing the the undesired part of the blow-off product will be achieved.

Apparatus for collecting a volatile condensate and for separating

An apparatus is disclosed for burning cement clinker which includes a preheater with inlet and outlet for heating gas and inlet and outlet for pulverous cement raw material, a suspension calciner with inlets for fuel, combustion air and preheated raw materials, outlet for combustion gas connected to the heating gas inlet of the preheater, and outlet for calcined material, communicating with the material inlet of a sintering furnace. The sintering furnace includes an inlet for fuel and combustion air, outlet for combustion gas communicating with the heating gas inlet of the preheater and an outlet for the sintered product connected to the material inlet of an air cooler for cooling the sintered product. The air cooler includes an air outlet connected both to the air inlet of the sintering furnace and to the air inlet of the suspension calciner. The sintering furnace is preferably in the form of a cylindrical drum rotatable around a slightly inclined axis and includes a suspension inlet duct provided with a material inlet and having a first end connected to the air outlet of the cooler and a second end connected to the upper end of the sintering drum substantially tangentially to the inner circumferential surface of the sintering drum. A fuel inlet or fuel inlets project into the suspension inlet of the sintering drum and/or into the suspension inlet duct. A combustion gas outlet duct is connected to one end of the sintering drum, and an outlet is provided for the sintered product at the lower end of the sintering drum.

Apparatus for thermally treating pulverous materials such as cement raw

A method for thermally treating pulverulent material, i.e., keeping the material at a certain temperature, the treating temperature, in a desired period of time, in particular sintering, pulverulent material in a rotary kiln slightly inclined to the horizontal. The method is especially applicable for thermally treating materials which tend to become sticky at the treating temperature, in particular for sintering pulverulent materials, i.e., agglomerating these by heating without complete melting. However, the method is also useful for general thermal treatment where sintering is not intended, e.g., for burning Bauxite, Mesa and phosphate bearing ores. An example of a sintering process to which the invention is particularly applicable is the manufacture of cement clinker where the pulverulent material to be sintered is hot calcined cement raw meal. An apparatus for practicing the method of the present invention is also disclosed.

Method and apparatus for thermally treating pulverulent materials

A method for thermally treating pulverulent material, i.e., keeping the material at a certain temperature, the treating temperature, in a desired period of time, in particular sintering, pulverulent material in a cylindrical reaction chamber with an axis slightly inclined to the horizontal after the material has been heated to the treating temperature outside the reaction chamber suspended in a gas. The method is especially applicable for thermally treating materials which tend to become sticky at the treating temperature, in particular for sintering pulverulent materials, i.e., agglomerating these by heating without complete melting. However, the method is also useful for general thermal treatment where sintering is not intended, e.g., for burning Bauxite, Mesa and phosphate bearing ores. An example of a sintering process to which the invention is particularly applicable is the manufacturing of cement clinker where the pulverulent material to be sintered is hot calcined cement raw meal. An apparatus for practicing the method of the present invention is also disclosed.

A plant for manufacturing cement clinker from cement raw material includes a preheater first stage separated by a wall into a first chamber and a second chamber. Only raw material is passed through the first chamber while only hot exit gases are permitted to pass through the second chamber. Thus the raw material including any volatile, combustion components are kept isolated from direct contact with the hot exit gases. A heat exchange system is provided to permit the transfer of heat from the hot exit gases in the second chamber to the raw material in the first chamber. The heat exchange system preferably includes self-contained heat pipes extending into both the first and second chambers. The heat pipes contain a fluid medium which aids in the heat transfer as a consequence of cylical changes of the fluid medium from a liquid to a vapor state. In one preferred embodiment to obtain improved heat transfer, granular heat-resistant material is placed within the second chamber and is formed into an expanded fluidized bed.

Plant for manufacturing cement clinker

A method and apparatus for measuring the temperature of hot fluids (1) in environments involving thermal radiation. The apparatus comprises at least one radiation-protected measuring body (4) constituting one end of a heat-tube (2) having a working temperature below the fluid (1) temperaure to be measured. The other end of the heat-tube (10) is connected to one end of a heat-conducting rod (8); the other end of which is kept cool by cooling means (11). The apparatus is equipped with temperature measuring means (12, 14) for measuring the temperature of the heat-tube as well as the temperature at two points along the heat-conducting rod. There can be more than one measuring body. The method comprises: (1) protecting the measuring body against heat transfer by radiation; (2) measuring heat emission to a radiation-protected measuring body; (3) maintaining the radiation-protected measuring body at a substantially constant temperature which is below the temperature of the hot fluid; (4) measuring the temperature of the radiation-protected measuring body; and (5) calculating the temperature of the hot fluid by: (a) dividing the heat emission by the product of the heat transfer coefficient of the heat transfer between the hot fluid and the radiation-protected measuring body by the surface area of the measuring body, and then, (b) adding to that value the temperature of the measuring body. It is unnecessary to heat the measuring body to the temperature of the hot fluid. The method can be applied to measuring the temperature of gases in kilns.

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Kolding, Denmark

Hans B Knudsen