US2414150A - Pneumatic conveyer - Google Patents

Description

Jan. 14, 1947. J. HIGGINS PNEUMATIC CONVEYER Filed Feb. 15, 1945 via:

' mmyroa v65 .5 fggflS Patented Jan. 14, 1947 UNITED STATES PATENT OFFICE PNEUMATIC CQNVEYER 'ohnL. Higgins, Chicago, Ill.

Appiication February 15, 1945, Serial No. 578,056

4 Claims.

1 This invention relates to pneumatic conveyer apparatus and will be described as applied to an ash conveyer apparatus such as us d by large steam power plants. However, it will be'appreciated that the invention has application to other pneumatic conveyer apparatus wherein similar problems are encountered and continuous, conveyor action is desired.

In many pneumatic ash conveys-rs such as used by power plants, the ashes must be taken from the ash pits located under the boilers to receiver tan-ks mounted at considerable heights at distant points from the power plants, where the ashes may be disposed of by gravity into dump cars on a railroad siding or sluiccd through a discharge line into a dump. This arrangement necessitates long conveyer pipe lines extending upwardly toward the receiver.

The conveyer apparatus is used periodically when the boiler room helper or ash man is instructed to empty the ash pit. In the conventional form of pneumatic conveyor apparatus utilizing a single receiver tank and vacuum system, the vacuum system operates on an on cycle of about two minutes and an off cycle of one minute, in order to provide a time interval for removing ashes in the receiver hopper tank which is under vacuum when being filled. During the off time interval, this receiver hopper is emptied.

When the vacand then the operation resumes. uum, is shut ofi for this reason, the ash in the upwardly extending conveyer line drops downwardly and packs in the pipe making resumption of the ash flow difficult and wasting the work already expended on the ashes.- is augmented by the continued piling of ashes in the inlet openin of the pipe line if the ash man continues his labors when the vacuum is shut oil.

It is the particular object of the present invention to avoid the dimculties of the oiT and on system of operation and to provide means whereby the continuous operation of the pneumatic conveyor is permitted.

Other objects and benefits will be disclosed in the following desc ions and Fig, l is an elevation view partly in section of the receiver-separator apparatus employing the invention; and

Fig, 2 is a top plan view thereof.

Now referring to the drawing: I designate, by the numeral it in dash lines, the course of the incoming ash line which, of course. will start at a level far below the receiver apparatus, The numeral E designates the tangential inlet pipe of this ash line to the receiver i2. This is a con- This difliculty rawing in which:

ventional type of receiver wherein'the ashes are led into the receiver in a tangential manner as is well understood in the art. Under the receiver i2 is the conventional conical hopper tank l3 which at times is closed by a swinging door I4 abutting inclined opening in a cupola inlet iii of another coacting bin hopper tank It. The bin hopper tank it has a conventional swinging discharge gate H which may be arranged to discharge directly into a dump car, storage tank, or it may be arranged to connect with a sluice pipe to carry ashes into a convenient dump. On top of the closed bin to is an upstanding pipe l9 connected to a conventional Venturi pipe 20 which in turn is connected to a tangential pipe 2! leading into a dust separator 22. The dust separator is emptied in a conventional manner through the pipe 23. A steam pipe 24 connects to the primary injector chamber 25 having nozes 26 coacting with the venturi 2!). When steam is permitted to enter the chamber 25 by means of an electrically controlled valve 21, which may be located at'any desirable location, the jets of steam from the nozzles 26 coactin with the venturi 2% cause a suction in the bin 16 which closes the spring. opened valve to, which is normally open to provide a vent to the atmosphere, and the suction therefrom is transmitted through the swinging door it to create a suction in thereceiver 52 which draws ashes through the lines I10 and H and deposits them in the conical hopper tank 23 of the receiver ttancl" through the door :4 into the bin tank it. Thus far the use of the venturi it to create a suction in the lines Hi and H is a conventional means to convey ashes in pipe lines except that the receiver l2 has been separated from the bin it by the hopper tank I3,

When this pneumatic removal of ashes has continued for sufiicient time to nearly fill the bin IS, the electrically controlled valve 21 is shut ofi automatically through the automatic time switch 8 thus stopping the flow of steam through the venturi 2e, and before this how of steam is completely stopped, another electrically controlled valve 28 in the pipe line 29 connected. to the supply line 24, is automatically opened by the switch 34 and electrical connections 35 and the steam emerging from this line 29 through the nozzle 39 coacting with another venturi 3| continues to create suction in the receiver I2 through the pipe 32. When this suction is applied through the pipe 32 to the receiver E2, the suction thus created closes the swinging door Hi and the ashes from the lines it and H are deposited in the hopper tank I3 of the receiver it. During this period of time, the ashes in the bin tank It are discharged by gravity upon release of the spring controlled valve t8, then valve 28 is shut 01f, the valve 2! opened, and the Venturi 20 picks up the vacuum load to thus continuously draw ashes through the lines In and II.

Thus I avoid the disadvantage of the ashes falling back in lines Ill and II, save the energy created by the inertia of the ashes in these lines, and remove ashes continuously. When the vacuum in the receiver l2 created by the Venturi 25] is transmitted through the pipe 32 to the Venturi 3|, the hinged valve 33 on the end of the Venturi 3| closes and efiectively cuts off the connection between the venturi 20 and 3|. By this arrangement, it will be appreciated that I have combined dual Venturi operations to avoid the difficulties and disadvantages when a single venturi and receiver is used and provide a continuous ash removal conveyer.

Having thus described my invention, I now claim as new? 1. In a pneumatic ash conveyer, a conveyer pipe line from an ash pit extending upwardly, a hopper bin tank having a swinging discharge gate mounted at a height considerably above the ash pit, a receiver attached to the conveyer pipe having a dump hopper and swinging discharge gate mounted above the bin tank with the dump hopper arranged to discharge into the bin tank, a dual Venturi suction device mounted on the bin tank with one suction device arranged to create suction in the receiver, the arrangement of the suction connections and the swinging discharge gates providing means to draw ashes through the receiver into the bin tank with one of the suction devices and to draw ashes through the receiver and into the receiver hopper by the other suction device, and means to control the operation of the two suction devices to permit dumpingof the ashes in the bin while continuing to draw ashes from the conveyer line into the receiver hopper, thereby providing a continuous ash conveying system.

.2. Ina conveyer of the character described, the combination of receiving and discharge chambers having means of communication therebetween adapted for the discharge of material from said receiving chamber into said discharge chamber, said receiving chamber being adapted to be connected with a fluid conduit for supply of material thereto, means for closing said communication, means connected with the discharge chamber for creating suction in said receiving and discharge chambers for sucking material into the receiving chamber for discharge therefrom into the discharge chamber, and means for creating suction in the receiving chamber upon closing of the communication between the chambers to continue the supply of material to the receiving chamber. I

3. In a conveyer of the character described, the combination of receiving and discharge chambers having means of communication therebetween and adapted for the passage of material from said receiving chamber to said discharge chamber, said receiving chamber being adapted to be connected with a fluid conduit for supply of material thereto, means for closing said communication therebetween, dual suction devices one of which is connected with the discharge chamber for creating suction therein and causing material to be drawn into the receiving chamber and discharged therefrom into the discharge chamber, and the other suction device being connected with the receiving chamber and having means for automatically creating suction therein upon the closure ofcommunication between the chambers to continue the supply of material to said receiving chamber while the material is being withdrawn from the discharge chamber.

4. In a conveyer of the character described, the combination of a hopper bin tank having a swinging discharge gate, a receiver adapted to be connected with a fluid conduit for supply of material thereto, said receiver having a dump hopper and a swinging discharge gate and mounted above the bin tank and arranged to discharge into said tank, dual Venturi suction devices connected with the bin tank with one suction device arranged to creat suction in the receiver, the arrangement of the suction connections and the swinging discharge gates providing means to draw material through the receiver into the bin tank by the action of one'of the suction devices and to draw material into the receiver to the discharge gate in closed position by the other suction device, and means for controlling the operation of the suction devices to permit dumping of the material in the tank while continuing to draw material into the receiver substantially in a continuous manner.

JOHN L. HIGGINS.

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