GB2115546A

GB2115546A - An apparatus for supplying fuel to and taking ash from a heating plant

Info

Publication number: GB2115546A
Application number: GB08301853A
Authority: GB
Inventors: Otmar Link
Original assignee: ZIMMERMANN AZO MASCHF; Azo Maschinenfabrik Adolf Zimmermann GmbH
Current assignee: ZIMMERMANN AZO MASCHF; Azo Maschinenfabrik Adolf Zimmermann GmbH
Priority date: 1982-02-13
Filing date: 1983-01-24
Publication date: 1983-09-07
Also published as: GB2115546B; GB8301853D0; BE895879A; JPS58150710A; DE3205142A1; FR2521695A1

Abstract

An apparatus for supplying and clearing materials to and from stationary small- to medium-sized heating plant (21) run on flowable solid fuel such as coal dust or coal breeze is made up of a transport unit with containers (1) for the fuel joined with a compressed air conveying unit, and furthermore a stationary unit which is placed at the heating system and has at least one fuel storage container (22) with a connector for joining it up with the said compressed air conveying unit. For clearing ash of the heating system the compressed air conveying unit of the transport unit may be run as a vacuum conveying unit, in which case the aspiration port of its blower (3) is joined up by way of a separator (14) with an empty container. This container is joined up through a vacuum line with the heating system for clearing the ash therefrom. <IMAGE>

Description

SPECIFICATION An apparatus for supplying materials to and taking materials from a heating plant The present invention is with respect to an apparatus for supplying and clearing materials to and from stationary small- to medium-sized heating plant run on solid but flowable fuels as for example coal dust or coal grains, and more specially to a form such apparatus having a transport unit with a container and a compressed air conveying unit on the one hand, and a stationary unit on the other and, the stationary unit being placed at the heating system and having at least one fuel storage container with a connector for joining it up with the compressed air conveying unit.

Herein the wording "small- to medium-sized heating plant" is used in the sense of plant with a small to medium heat output as used in private houses, groups of flats, public buildings and the like, but not plant with a high output as for example the heat producing part of a district heating system.

Up till the present time plant of the sort in question has for the most part been run on liquid or gas fuel, this offering the useful effect of simple control being possible, while on the other hand the small amount of plant run on solid fuels such as coal or the like still in existence mostly has to be stoked by hand, which makes much work, automatic operation hardly being possible because of the solid nature of the fuel, of the long burning time etc. Of late attention has been given to the idea of running heating plant with a small to medium heat output on flowable solid fuels such as coal dust and coal grains, such fuels having in fact been used for firing district heating systems for some time.A number of troubles in connection with the delivery of the solid fuel to the consumer for example, and taking away the large amounts of ash produced, have however stopped such fuels coming into general use.

One purpose of the present invention is that of designing an apparatus making it possible for materials of the sort noted to be delivered to and cleared from heating plant of small to medium size in a simple way and at a low price.

A further purpose of the invention is designing such an apparatus that may be run generally automatically.

For effecting these and further purposes or objects the invention takes the apparatus noted hereinbefore as a starting point, said apparatus for supplying flowable solid fuel to, and clearing ash from a small- to medium-sized heating plant, comprising, in keeping with the invention, a transport unit for fuel and ash, at least one transport container on said unit, a compressed air conveying unit on said unit, and a stationary unit at said heating plant, said heating plant being fitted with at least one fuel storage container with a connector for joining with said compressed air conveying unit, the same being able to be switched over to vacuum operation, a blower forming part of said conveying unit, a separator, said blower being able to be joined with said transport container by way of said separator, and a vacuum line for connection of said transport container with said heating plant for taking up ash therefrom and running it into said transport container.

Using a transport unit which in some respects is of normal design and size, that is to say with the container and the compressed air conveying unit, the loose, flowable fuel is pumped into the consumer's storage container. The ash produced in the heating plant may be taken away in the unit because of its design in keeping with the present invention. To do this it is only necessary for the vacuum line to be joined up between the heating plant and the empty container and for the compressed air conveying unit to be run as a vacuum conveying unit so that, by way of the blower, vacuum is produced in the separator and in the empty container and the vacuum line as far as the heating plant, this making it possible for the ash to be aspirated and to be taken up into the empty container. It is in this way that the supply of fuel and the taking away of the ash may be made generally automatic.The only manual operations needed are the connection and unjoining of the vacuum line between the container and storage container and of the vacuum line between the heating plant and the transport container.

In keeping with a preferred form of the invention, the transport unit has a number of equal-sized fuel containers of which each is able to take up an amount of material equal to the amount of material stored in the storage container of the stationary unit, and of which at least one may be joined up with the heating plant by way of the vacuum line.

Such a design makes it possible for every storage transport container to be filled with about the amount of flowable solid fuel as ordered by the consumer so that delivery to the consumers is becomes simpler. Furthermore it is possible to make certain that once the transport unit has got to the first of a number of consumers to be supplied at least one of the containers may be completely emptied and will then be ready to take up ash. In keeping with the size of the ash storage container at the consumer, the ash may be transported away every time he is supplied with fuel or only after longer stretches of time. If ash is taken from all consumers every time they are supplied with fuel, one container of the transport unit may be large enough to take up the ash from every one of them.In the case of consumers having a large heating plant or if the ash is only taken from them after long stretches of time, that a representatively greater number of containers for ash with connections for the vacuum line may be used.

In a preferred form of the invention one may have a vacuum conveying unit between the fuel storage container of the stationary unit and the heating plant, the blower of the conveying unit having its inlet port joined up by way of a separator with the outlet point of the storage container and having its pressure or outlet port joined up with the air cushion of the said container, the storage container having an air blow-off line.

It is in this way that it is now possible for the supply of the flowable fuel from the storage container to be run automatically. Because in such a conveying operation generally it is only a question of low rates of fuel transport, the use of a vacuum conveying unit is preferred. For making certain that no dust or volatile substances from the said fusl are leaked out into the air next to the stationary unit, the pressure port of the aspiration conveying unit is joined up with the storage container so that all of the conveying unit is shut off from the outside and gases or clouds of dust, that may be produced in the storage container, are let off, for example to a point outdoors.

In the case of this last-named form of the invention the outlet port of the separator is best joined up with a connection space, that may be shut off from the separator and which is joined up with the boiler of the heating plant by way of a conveyor.

The fuel aspirated in one conveying cycle into the separator is deposited in the separator and the run into the connection space and then may be transported therefrom by a mechanical conveying unit, as for example a screw conveyor or the like, to the boiler of the heating plant. The rate is controlled by way of the conveying cycle of the vacuum conveying unit or by way of the conveying cycle of the vacuum conveying unit or by way of the conveying cycle of the mechanical input system, care being taken in the last case always to see that there is enough material filled into the connection space.

Further details and useful effects of the invention may be seen from the account now to be given of one working example of the invention using the accompanying figure, that is a diagrammatic flow chart.

In the figure those parts of the apparatus which are part of the transport unit are framed in by a broken line. In the working example viewed the transport unit is made up of a number of transport containers 1 of the same design that are placed, for example, one in front of the other and if need be side by side, on a vehicle that is not be seen in the figure. The transport unit is further fitted with a compressed air conveying system 2 having a blower 3. The pressure port of the blower 3 is joined up by way of line 4 and branch lines 5 with the outlets of all containers 1. Each branch line 5 has its own shut-off valve 6 whereas there is fixedadjustment choke 7 directly upstream from each container outlet.By opening up a shut-off valve 6 of a selected container the compressed air is made to go through the choke 7 with a fixed adjustment at a generally unchanging pressure to flow rate ratio into the outlet is joined up by way of a vacuum line 30 with the outlet 31 of the storage container 22. A shut-off valve 41 is fitted in the vacuum line 30. The outlet or pressure port of the blower 27 is joined by way of a line 32 with the storage container 22, this line 32 opening at a higher level than the filter 23 in the storage container.The separator is further joined with a connection space 33, that at its lower end has a mechanical conveyor 34, as for example a screw conveyor and furthermore there are sensors, one sensor 35 sensing when the space 33 is full and turning on the vacuum conveying unit 26, and one sensor 36 for sensing when it is empty and turning off the unit 26, the conveying unit supplying fuel to the firebox of the boiler.

The inlet line 24 of the storage container 22 is fitted with a connector 37 that may be joined up with the compressed air conveying line 38, that for its part comes from the outlet of the transport containers 1 of the transport unit.

One or more transport containers 1 of the transport unit have connections 39 at their top ends for joining with a vacuum line 40, that is joined up with the ash space or box (not marked in the figure) of the heating plant. This vacuum line 40 may be a bulk conveying hose, to take the simplest form.

An account will now be given of the operation of the apparatus.

After the transport containers 1 have been filled with a weighed-out amount of fuel, as for example coal dust, coal breeze of the like, at a main coal store through an opening 12, in which respect the amount taken up in each transport container 1 may be roughly equal to the amount requested amount, the fu.el is transported to the consumer, where the pressure line 38 of the vehicle is put on the connector 37 of the inlet line 24 of the storage container 22. Before starting up the blower 3 the shut-off valve 6 of the container that is to be emptied is opened, all other shut-off valves 6 fitted in the branch lines 5 being kept shut the while. For working the system under pressure the air induction valve 11 (with filter) fitted to the inlet port 10 of the blower 3 is opened, whereas the valve 20 on the pressure part 19 is shut down.

The air taken in by way of the valve 11 is forced by the blower 3 through the main line 4 and the open branch line 5 and its choke 7 with a fixed adjustment into the outlet of the container 1 so that the fuel therein makes its way through the pressure line 38 and the inlet line 24 into the storage container 22. The coal dust is not leaked out of the storage container 22 because of the filter 23, whereas volatile substances are let off through the air blow-off line 25.

The heating plant is supplied with fuel using the aspiration conveying unit 26 on opening the shutoff valve 41 and turning on the aspiration blower 27. The loose or flowable fuel at the outlet 31 of the storage container 22 is conveyed by the vacuum effect through the vacuum line 30 into the separator 28 and separated here from its suspending air. The clean air, possibly still mixed with some fine dust and having a least some volatile substances therein is pumped by the blower 27 through the vacuum line 29 and the pressure line 32 into the storage container 22 at a point higher up than the filter 23, from which point the volatile substances are let off out through the air blow-off line 25.

The fuel coming into the separator 28 is let off therefrom through a valve as for example one in thx form of a door or butterfly valve, the fuel then moving into the connection space 33, from which it is moved by the conveyor 34 screw into the boiler. The turning on and off of the aspiration blower 27, and with it the pumping of the fuel, may be controlled by way of the sensor 36 and the sensor 35 that are worked when the'space is empty and when it is full. Control may furthermore be by way of the shut-off valve 41 in the vacuum line 30, although in this case it has to be kept shut when the storage container 22 is being filled.

For clearing the plant of ash, an empty transport container 1 is joined with the ash box of the heating plant 21 using the vacuum line that is joined up with the box. The valve 20 on the pressure side 19 of the blower 3 is opened, it now functioning as a blow-off valve, whereas the air intake valve 11 on the side which was earlier the pressure side is shut. Furthermore the shut-off valve 1 8 fitted in the branch line 1 7 of the container in question is opened, whereas the shutoff valves 18 of the rest of the transport containers and furthermore the shut-off valves 6 fitted in the branch lines of the transport containers are kept shut. On starting up the blower vacuum is produced in the empty container 1, the air being pumped off through the line 13, the separator 14 and the line 1 6. The container in question then because of the vacuum in it, takes up ash through the vacuum line 40 from the ash box. In this respect it is naturally necessary for air to be let into the ash box for conveying the ash therefrom.

When all the ash has been taken up, the vacuum line 40 is unjoined at connection 39. Furthermore the pressure line 38 is unjoined from the inlet line at connector 37. The transport unit may now go to the next consumer.

Claims

1. An apparatus for supplying flowable solid fuel to, and clearing ash from a small- to mediumsized heating plant, comprising a transport unit for fuel and ash, at least one transport container on said unit, a compressed air conveying unit on said unit, and a stationary unit at said heating plant, said heating plant being fitted with at least one fuel storage container with a connector for joining with said compressed air conveying unit, the same being able to be switched over to vaccum operation, a blower forming part of said conveying unit, a separator, said blower being able to be joined with said transport container by way of said separator, and a vacuum line for connection of said transport container with said heating plant for taking up ash therefrom and running it into said transport container.

2. An apparatus as claimed in claim 1 comprising a number of such fuel transport containers of like form on said transport unit, each thereof being designed to take up an amount of fuel roughly equal to the amount of fuel taken up in said storage container, at least one of said transport containers being able to be joined up with said heating plant separately at will.

3. An apparatus as claimed in claim 1 or claim 2 comprising further a vacuum conveying unit placed between the storage container and the heating plant, said vacuum conveying unit being fitted with a blower, a separator, means for connection of an inlet port of said blower through said separator with an outlet point of said storage container and connections of an outlet port of said blower with an air cushion of said container, and an air blow-off line joined with said storage container.

4. An apparatus as claimed in any one of claims 1 to 3 comprising a connection space joined up with an outlet port of said separator of said of the vacuum conveying unit, means for shutting off said space from said outlet port and a conveyor for transport of material from said space to said boiler of said heating plant.

5. An apparatus as claimed in claim 1 substantially as described hereinbefore with reference to and as illustrated in the accompanying figures.