An apparatus for pneumatically conveying bulk material includes a conveyor line for transporting the bulk material and a secondary line which carries clean gas and is sectionized by spaced three-way/two-way directional control valves. Each control valve is actuated by a pressure transmitter which compares the actual pressure in the conveyor line with the desired pressure in a third line carrying a fluid at a desired pressure decreasing in downstream direction in accordance with the pressure drop in the conveyor line during normal operation. A communication between the conveyor line and the second line is provided by respective branch lines which define the third connection of the control valves and are multiply connected to the conveyor line. Thus, upon encountering a pressure drop in an area of the conveyor line, the respective pressure transmitter actuates the pertaining control valve which shuts off downstream section of the second line and connects the second line with the conveyor line for introducing clean gas into the conveyor line at the desired area thereof.

Apparatus for pneumatically conveying bulk material

A method of unblocking conveying pipes (3) for particulate material comprises feeding air to the pipe at spaced apart positions therealong in order to reduce the length of the blocking material. The air is injected into the pipe at positions which are preferably spaced apart by a distance less than the critical particulate material plug length to conveying pipe diameter ratio that will result in a pipe blockage that cannot be moved by application of pressure applied to one end of the particulate material plug. Apparatus for carrying out the method is also described.

Method and apparatus for unblocking conveying pipes for particulate material

Process and apparatus for pneumatic or hydraulic transport of bulk material in a conveying direction through a pipeline by means of over or underpressure, in which components are provided for monitoring the pressure prevailing at a plurality of successive points along the pipeline, providing a plurality of sources of a pure gas or liquid each at a pressure corresponding to the pressure prevailing at an associated point along the pipeline, and supplying the pure gas or liquid from each source to the point along the pipeline which succeeds, in the conveying direction, the associated point for that source, while preventing any fluid flow from the pipeline to each source.

Process and equipment for pneumatic and hydraulic transport of bulk materials through pipes

The invention relates to a dry ice explosion and air-permeability-enhancing device for a low-air-permeability coal seam and a method for drawing out gas by using the dry ice explosion and air-permeability-enhancing device. The dry ice explosion and air-permeability-enhancing device is characterized in that an explosion initiation device consists of an explosion initiator arranged outside a drill hole, a lead arranged in the drill hole and a detonator connected with the lead; a heat-insulating storage device consists of a dry ice storage chamber arranged in a coal body, an inner housing arranged outside the dry ice storage chamber, a first vacuum chamber arranged outside the inner housing, an outer housing arranged outside the first vacuum chamber, a sealed male thread connected with the dry ice storage chamber and a conveying rod, a sealed female thread connected with the sealed male thread and a detonator cavity connected with the sealed female thread; a hole sealing device consists of polyurethane arranged in the drill hole; the explosion initiation device utilizes gas formed by heat-absorbing sublimation of the dry ice to generate high pressure in a limited and sealed space to cause a physical explosion to damage the inner housing of the heat-insulating storage chamber, and the coal body is damaged by shock waves generated by the explosion, so that a channel is provided for gas transportation, the air permeability of the coal seam is improved, the gas drainage ratio is increased, and safety is guaranteed.

Shmidt Viktor F

Papers

Apparatus for pressure-head conveying of loose materials through pipeline

Method of degassing methane-laden coal seams