Method and apparatus for the pneumatic conveying of fine bulk material

A method of pneumatically conveying fine bulk material comprising:

• (a) providing an apparatus comprising,
• (i) a pneumatic conveying pipe having upstream and downstream portions, said pneumatic conveying pipe having a first portion which is located upstream from a second portion, and a discharge point located further downstream from said second portion,
• (ii) a charging container that is in reversibly closeable communication with a charging point of said pneumatic conveying pipe, said charging point being located further upstream from said first portion of said pneumatic conveying pipe,
• (iii) a suction conveying device which is in reversibly closeable gaseous communication with a suction point of said pneumatic conveying pipe, said suction point being located between said first and second portions of said pneumatic conveying pipe,
• (iv) a pressure conveying device that is in reversibly closeable gaseous communication with a portion of said pneumatic conveying pipe at a point that is further upstream from said charging point,
• (v) a conveying gas supplementary line having one of a closed end and a reversibly closeable end, said pressure conveying device being in reversibly closeable gaseous communication with said conveying gas supplementary line, and
• (vi) a plurality of shut-off devices providing reversibly closeable gaseous communication from said conveying gas supplementary line into said pneumatic conveying pipe;
• (vii) a shut-off apparatus providing gaseous communication from said first portion of said pneumatic conveying pipe to said second portion of said pneumatic conveying pipe;
• (b) filling, in a first step, said first portion of said pneumatic conveying pipe with a fine bulk feed material from said charging container through said charging point by means of said suction charging device drawing said fine bulk feed material into said first portion of said pneumatic conveying pipe;
• (c) transferring, in a second step, the fine bulk feed material from said first portion to said second portion of said pneumatic conveying pipe, by means of said pressure conveying device which introduces conveying gas into said pneumatic conveying pipe;
• and
• (d) conveying, in a third step, the fine bulk feed material from said second portion of said pneumatic conveying pipe to said discharge point, by means of said pressure conveying device,
• wherein each of said second portion of said pneumatic conveying pipe and said conveying gas supplementary line are provided with a constant quantity of conveying gas.