Pipeline transportation method of coal

Abstract

A pipeline transportation method of coal is provided. The coal is pulverized and then subjected to a waterproofing treatment, so that a time needed for precipitating the pulverized coal in water is longer than a time needed for transporting the pulverized coal by flowing water to a destination. The waterproof pulverized coal is transported by water through a pipeline. After reaching the destination, the waterproof pulverized coal can be separated from the water in a static pool, collected by a cyclone separator, and then stored in a warehouse.

Claims

1. A pipeline transportation method of coal, the method comprises: pulverizing coal to obtain pulverized coal having a diameter of 500 m or less; performing a waterproofing treatment on the pulverized coal; and transporting the waterproof pulverized coal to a destination, which comprising: pumping water into a pipeline until a constant flow rate of the water is reached; adding the waterproof pulverized coal into the pipeline, such that the waterproof pulverized coal can be transported by the water at a uniform rate; pressurizing a mixture of the waterproof pulverized coal and the water by a shear-free pump, or pressurizing the water only by a centrifugal pump after separating the waterproof pulverized coal from the water and then adding the separated waterproof pulverized coal back to the water; directing the mixture of the waterproof pulverized coal and the water into a static pool, so that the waterproof pulverized coal can float on the water surface and the water can be discharged; collecting the waterproof pulverized coal by a cyclone separator via a negative pressure collection method; and storing the collected waterproof pulverized coal in a warehouse at the destination, wherein a specific weight of a single particle of the waterproof pulverized coal is less than a specific weight of the water, wherein a time needed for precipitating the waterproof pulverized coal in water is longer than a time needed for transporting the waterproof pulverized coal to the destination.

2. The pipeline transportation method of claim 1, wherein the waterproofing treatment is paint spraying, waxing, or chemical treating surfaces of the pulverized coal.

3. The pipeline transportation method of claim 2, wherein the waxing method comprises: adding 0.2-20 wt % of paraffin wax or paraffin emulsion to the pulverized coal t form a mixture; and heating and rolling the mixture to a temperature of at least 80 C. for at least 20 minutes.

4. The pipeline transportation method of claim 2, wherein the chemical treating method comprises: adding 5-30 wt % of calcium salt, 0.2-10 wt % stearate or a salt of stearate, 0.2-10 wt % of paraffin wax to the pulverized coal to form a mixture; and heating and rolling the mixture to a temperature of at least 120 C. for at least 20 minutes at a heating rate of 2 C./min.

5. The pipeline transportation method of claim 4, wherein the calcium salt comprises CaCO.sub.3.

6. The pipeline transportation method of claim 4, wherein a heating rate of the heating step is about 2 C./min.

7. The pipeline transportation method of claim 2, wherein the chemical treating method comprises: adding 5-20 wt % of Ca(OH).sub.2 to the pulverized coal to form a uniform mixture; adding 1-10 wt % of a solution of a fatty acid ammonium to the mixture; and drying the mixture.

8. The pipeline transportation method of claim 2, wherein the chemical treating method comprises: adding 2-20 wt % water-soluble sodium methylsilanolate and 5-20 wt % of CaCO.sub.3 to the pulverized coal to form a mixture; stirring the mixture; and drying the mixture.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawings are included to provide further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments and, together with the description, serve to explain the principles of the disclosure.

(2) FIG. 1 is the flowchart of the method.

(3) FIG. 2 is the schematic depiction.

DESCRIPTION OF THE EMBODIMENTS

(4) The present invention will now be described in further detail with reference to embodiments.

(5) The present invention provides a method for long-distance pipeline transportation of coal and its related process, characterized in that the method comprises the following steps:

(6) a) pulverizing the coal to obtain a pulverized coal having a diameter of 500 m or less;

(7) b) performing a waterproofing treatment on the pulverized coal and then soaking the pulverized coal in water, so that the time needed for precipitating the pulverized coal in the water is longer than the time needed for transporting the pulverized coal to a destination;

(8) c) pumping water into pipeline and then adding the waterproof pulverized coal after the water flow within the pipeline reaches a certain flow rate, such that the pulverized coal can be transported at a uniform rate;

(9) d) pressurizing a mixture of the waterproof pulverized coal and water with a shear-free pump, which is a specific pump that applies no shear forces to the fluid being delivered, when the mixture of the waterproof pulverized coal and water needs to be pressurized to increase the flow rate before flowing to the destination, or pressurizing the water with a centrifugal pump after separating the pulverized coal from water and then adding the separated waterproof pulverized coal; and

(10) e) introducing the mixture of the waterproof pulverized coal and water into a material-separating pool having a static pressure after the mixture of the waterproof pulverized coal and water flows to the destination, wherein a filter and a drainage hole are provided below the material-separating pool, the dry waterproof pulverized coal floats on the water surface by buoyancy, and water is discharged below and introduced into the pipeline after pressurization for reusing; and introducing the waterproof pulverized coal into a cyclone separator from the surface of the material-separating pool by using a vacuum collecting method to separate the pulverized coal from gas and then introducing to a pulverized coal bunker for use.

(11) The waterproofing treatment is a process of paint spraying or waxing the surface of a single particle of pulverized coal or a chemical process.

(12) The waxing process comprises adding 0.2 to 20% of paraffin wax or paraffin emulsion (liquid paraffin) to the pulverized coal, and the pulverized coal is rolled heated up to 100 C. or higher for 20 minutes or more;

(13) Three kinds of chemical processes for waterproofing treatment are described herein. The first chemical process comprises adding 5 to 30 wt % of CaCO.sub.3 or calcium salts, 0.2 to 10 wt % of stearic acid or stearate and 0.2 to 10 wt % of paraffin wax to the pulverized coal, and the pulverized coal is heated to about 120 C. for 20 minutes or more; wherein the heating rate is 2 C./min. The second chemical process comprises adding 5 to 20 wt % of calcium hydroxide to the pulverized coal and mixing them evenly. 1 to 10 wt % of solution of ammonium aliphatate are added and the mixture is stirred thoroughly to form a paste and then is dried. The third chemical process comprises adding 2 to 20 wt % of water-soluble sodium methylsilanolate and 5 to 20 wt % of CaCO.sub.3 to the pulverized coal. The mixture is stirred thoroughly and dried.

(14) The following considerations should be taken into account when utilizing the method of the present invention:

(15) i. When the coal of different types is made into waterproof pulverized coal, the specific weight (or density) of a single particle of the waterproof pulverized coal is less than that of the liquid carrier (i.e. water).

(16) ii. The pulverized coal requires waterproofing treatment. Different waterproof treatment processes are employed depending on the distances for transporting the pulverized coal (i.e. the suspending time, before precipitation, of the waterproof pulverized coal after being soaked in the water) to reduce the cost for waterproofing treatment.

(17) iii. An antifreezer may be added to the water being delivered based on the ambient temperature, such that the water is allowed to flow at a low temperature. The antifreezer of calcium salts is preferred.

(18) It should be noted that the above embodiments are merely illustrative of the present invention and are not limited thereto. Although the present invention has been described in detail with reference to preferred embodiments, it will be understood by those skilled in the art that the present invention may be modified and substituted equivalently without departing from the spirit and scope of the present invention. These modifications and equivalent substitutes are intended to be included within the scope of the claims of the present invention.