US 4,415,296 AGranted

Materials transfer system and methodology

AssigneeKamyr, Inc.

InventorErwin D. Funk

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Abstract

A method and system are provided for continuously conveying hard particulate material of non-uniform size, like coal. A high pressure transfer device has high and low pressure feed and discharge lines extending to and from it, and a screen arrangement for allowing liquid and fines to pass from the low pressure feed line to the low pressure discharge line, while stopping large particles. An excess accumulation of fines is prevented by providing a screen assembly vertically above the high pressure transfer device. Level control in a hopper--which provides the low pressure feed line--is accomplished merely utilizing an overflow technique. The concentration of particles in the liquid in the high pressure discharge line is maintained about 50% by withdrawing a portion of the liquid (while still under pressure) from the high pressure discharge line, and returning it to the high pressure feed line. A density measuring device downstream of the liquid withdrawal automatically controls the amount of liquid withdrawal.

Claims25

Dependent claims

A method of continuously conveying hard particulate material of non-uniform size, such as coal, utilizing a high pressure device including a pocketed rotor containing a pair of diametrically through-going pockets perpendicular to each other, a housing enclosing the rotor and having four ports equally spaced around the periphery thereof for registry with inlets and outlets to and from the through-going pockets in the rotor, at least one screen associated with the housing and rotor for allowing passage of liquid and fine particles therethrough, but preventing passage of particles larger than a predetermined size therethrough, and high and low pressure feed lines and discharge lines leading to and from the rotor ports;

the method comprising the steps of
(a) continuously feeding liquid, containing the hard particulate material, under low pressure in a low pressure feed line into a first of the housing ports for entry into a through-going pocket of the rotor;
(b) rotating the rotor in a given direction of rotation, so that the pocket openings therein progressively rotate past each of the housing ports;
(c) providing low pressure withdrawal of liquid introduced through the first port from through-going pockets of the rotor through a third port of the housing into a low pressure discharge line, opposite the first port, and screening the particulate material above a predetermined size out of the liquid passing through the third port with the at least one screen;
(d) pumping liquid under high pressure in a high pressure feed line toward the rotor through a fourth port of the housing, the fourth port being located before the first port in the direction of rotation of the rotor, and between the first and third ports;
(e) providing withdrawal of liquid and material through a second port, located opposite the fourth port, into a high pressure discharge line;
(f) withdrawing a portion of the liquid, while under high pressure, from the high pressure discharge line to increase the solids concentration in the high pressure discharge line;
and
(g) returning liquid withdrawn in step (f) to the high pressure feed line, boosting the pressure thereof so that it corresponds generally to the pressure of the liquid in the high pressure feed line.

6 more elements

Apparatus for conveying hard particulate material of non-uniform size, comprising:

a high pressure transfer device comprising:
a rotor containing a pair of diametrically through-going pockets perpendicular to each other;
a housing enclosing the rotor and having first, second, third and fourth ports equally spaced around the periphery thereof for registry with inlets and outlets to and from the through-going pockets;
and at least one screen associated with the housing and rotor for allowing passage of liquid and fine particles therethrough, but preventing passage of particles larger than a predetermined size therethrough;
a low pressure feed line attached to the housing first port;
a low pressure discharge line attached to the housing third port, which is opposite the first port;
a high pressure feed line attached to the housing second port, which is between the first and third ports;
a high pressure discharge line attached to the housing fourth port, which is opposite the second port;
a low pressure pump disposed in said low pressure discharge line;
and
a high pressure pump connected to the high pressure feed line;
wherein the improvement comprises:
means for withdrawing a portion of the liquid, while under pressure, from the high pressure discharge line so that the solids concentration in the high pressure discharge line is increased;
and means for returning liquid withdrawn from the high pressure discharge line to the high pressure feed line between the high pressure pump and the high pressure transfer device, said means including a boosting pump for boosting the pressure of said returning liquid so that it corresponds generally to the pressure of the liquid in the high pressure feed line.

11 more elements

Dependencies are inferred from the claim text.