Pressurized tank and a device and method for feeding powder to a piping for conveying the powder

Patent metadata

Field	Value
Publication number	US-10259666-B2
Application number	US-201415126155-A
Country	US
Kind code	B2
Filing date	Jul 17, 2014
Priority date	Mar 14, 2014
Publication date	Apr 16, 2019
Grant date	Apr 16, 2019

Abstract

A pressurized tank is provided in which no air flows back from a piping for conveying powder to the pressurized tank. A pressurized tank (A) is used for a device (B) for intermittently feeding a predetermined amount of powder to a piping (7) for conveying the powder when the powder is conveyed in a plug flow through the piping (7) by means of compressed air. The tank (A) has a first pressurized room (6) that is a pressure vessel and that has a funnel-shaped upper partition (3) that has an opening and a funnel-shaped lower partition (4) that also has an opening, a first check valve (9) that is provided beneath the opening of the upper partition (3) of the first pressurized room (6) and is vertically moved so as to be upwardly moved by means of compressed air to close the opening of the upper partition (3), a second check valve (10) that is provided beneath the opening of the lower partition (4) of the first pressurized room (6) and is vertically moved so as to be upwardly moved by means of compressed air to close the opening of the lower partition (4), and an elastic body (24) to upwardly bias the second check valve (10).

First claim

The invention claimed is:

1. A pressurized tank that is used in a device for intermittently feeding a predetermined amount of powder to a piping for conveying the powder when the powder is conveyed in a plug flow through the piping for conveying the powder by means of compressed air, the tank comprising:
a first pressurized room that is a pressure vessel and that has a funnel-shaped upper partition that has an opening and a funnel-shaped lower partition that has an opening, wherein the lower surface of the first pressurized room is configured to be hermetically attached to one end of a second pressurized room of the device so that the one end of the second pressurized room encloses the opening of the lower partition of the first pressurized room;
a first check valve that is provided beneath the opening of the upper partition of the first pressurized room and is vertically moved so as to be upwardly moved by means of compressed air to close the opening of the upper partition;
a second check valve that is provided beneath the opening of the lower partition of the first pressurized room and is vertically moved so as to be upwardly moved by means of compressed air to close the opening of the lower partition; and
an elastic body to upwardly bias the second check valve, wherein the elastic body biases the second check valve so as not to open the valve when the compressed air is supplied to the second pressure room, but not to the first pressure room, and so as to open the valve when the compressed air is supplied to the first pressure room.

2. The pressurized tank of claim 1 , wherein the elastic body is a coil spring that cancels a weight of the second check valve by hanging the second check valve.

3. A device for intermittently feeding a predetermined amount of powder to a piping for conveying the powder by using the pressurized tank of claim 1 or 2 , the device comprising:
a hopper that stores powder to be conveyed and has a port for discharging the powder at a bottom and that has a cutoff gate;
a hollow room that connects the port for discharging the powder of the hopper with the opening of the upper partition of the first pressurized room;
a second pressurized room, one end of which is hermetically attached to a lower outer surface of the first pressurized room so as to enclose the opening of the lower partition of the first pressurized room, and the other end of which is connected to a proximal end of the piping for conveying the powder;
a first shut-off valve that connects and disconnects a lower surface of the first check valve with an air source through a first piping;
a second shut-off valve that connects and disconnects a lower surface of the second check valve with an air source through a second piping;
a third shut-off valve that can discharge the compressed air in the first piping;
a sensor that detects a presence or an absence of powder in the first pressurized room of the pressurized tank; and
a controller that controls the cutoff gate and the first, second, and third shut-off valves based on detection by the sensor, so that the cutoff gate and the first, second, and third shut-off valves open and close to function together.

4. A method for intermittently feeding powder to a piping for conveying the powder by using the device of claim 3 , the method comprising the steps of:
(1) when the sensor detects an absence of the powder, then, under control of the controller, closing the first shut-off valve and opening the third shut-off valve, to discharge the compressed air from the first pressurized room of the pressurized tank;
(2) opening the cutoff gate to feed the powder in the hopper to the hollow room, supplying the compressed air from the opened second shut-off valve to the second check valve and the second pressurized room, so as to upwardly move the second check valve to close the opening of the lower partition of the first pressurized room, so as to convey the powder in the piping for conveying the powder in a plug flow by the compressed air, and so as to downwardly move the first check valve by a weight of the first check valve and a weight of the powder that has flowed from the hopper to open the opening of the upper partition of the first pressurized room to supply the powder in the hollow room to the first pressurized room, and after a lapse of a predetermined time after the sensor detects the absence of the powder, closing the second shut-off valve to stop supplying compressed air to the second check valve and the second pressurized room;
(3) when the sensor detects a presence of the powder after the powder has flowed into the first pressurized room, then, under the control of the controller, closing the cutoff gate, closing the third shut-off valve, and opening the first shut-off valve so that compressed air is supplied to the first check valve and the first pressurized room so as to upwardly move the first check valve to close the opening of the upper partition of the first pressurized room and so as to downwardly move the second check valve by means of pressure at the first pressurized room and a weight of the powder to open the opening of the lower partition of the first pressurized room; and
(4) immediately after the opening of the lower partition is opened, opening the second shut-off valve to supply compressed air to the second check valve without upwardly moving the second check valve so as to fluidize the powder that is passing through the opening of the lower partition of the first pressurized room by means of air that has flowed from the second check valve, so that the powder in the first pressurized room is fed to the piping for conveying the powder.

5. A method for intermittently feeding a predetermined amount of powder to the piping for conveying the powder by using a plurality of the devices of claim 3 , wherein timing for activating the cutoff gate and the first, second, and third shut-off valves of each device is delayed by a time (1/N) that is divided by a number (N) of devices to be used.

Assignees

• Sintokogio Ltd

Inventors

• Aoki Yukinori

Classifications

• B65G53/22

  the systems comprising a reservoir, e.g. a bunker · CPC title

• B65G2812/1616

  Common means for pneumatic conveyors · CPC title

• B65G2812/1641

  Air pressure systems · CPC title

• B65G53/525 Primary

  for conveyance in plug-form · CPC title

• B65G2201/042

  Granular material · CPC title