FR2466044A1 - METHOD FOR PNEUMATICALLY TRANSPORTING FINE GRAIN FUEL TO A GASIFIER - Google Patents

Abstract

PROCESS FOR CONTROLLING A DEVICE FOR THE PNEUMATIC TRANSPORT OF FINE GRAIN FUEL TO A GASIFIER, THE TRANSPORT GAS AND A PRESSURE MAINTAINING GAS BEING INTRODUCED IN A PRESSURE TANK EQUIPPED WITH A SAS DEVICE AND CONDUCTING THE GASBUSTIBLE THROUGH TRANSPORT PIPES. THE REGULATION OF THE QUANTITY OF FUEL SUPPLIED TO THE GASIFIER 10 IS CARRIED OUT THROUGH A DEVICE 20 WHICH MEASURES THE DIFFERENCE BETWEEN THE PRESSURE IN THE TRANSPORT TANK 11 AND THE PRESSURE IN THE GASIFIER 10.

Description

Method for pneumatically conveying fine grain fuel

  to a gasifier. The invention relates to a method for controlling

  a device for the pneumatic transport of fuel

  tar in fine grains to a gasifier, the transport gas and a pressure maintenance gas being introduced into a pressure tank fitted with a

  airlock device and leading the fuel to the

zeifier through transport pipes.

  It is known to provide such trans-

  port of so-called jet systems: this is understood to mean

  tubular lines passing through the wall of the tank and being able to be displaced vertically for the transport gas, an open pipe of the same dimensions, used for transporting fuel, ground and dried coal,

towards the gasifier being arranged coaxially

  above the upper end of the pipe. The lower pipe section can be moved for example over a distance of 50 mm; this allows you to adjust the height of the annular gap between the ends

of the two pipes, and also to close this interval.

The invention proposes to also regulate

as simple as possible the amount of fuel that is sent to the gasifier through

of the transport tank.

Experiments on such trans-

  port have given as a surprising result that there are

a linear dependence between the quantity of

fine grain target brought to the gasifier by the

pipe connecting the transport tank and the

  zeifier, and the difference between the pressures

  gaining on the one hand in the transport tank and

  on the other hand in the gasifier.

  Consequently, the invention proposes to provide a device which measures said pressure difference for use as a sensor for regulating the

quantity of fuel supplied to the gasifier. The re-

  gulation can be carried out for example by modifying the flow rate of the pressure maintenance gas introduced into the transport tank. Regulation can also be carried out by acting on other operating variables, on which the quantity of fuel depends.

brought to the transport tube.

The device which measures the pressure difference is coupled to a device which is set to the set point of a determined pressure difference which

corresponds to the desired quantity of coal transported.

When the real value deviates from it, a regulatory body

glage which modifies the flow of gas to maintain the

pressure is activated.

  The present invention will be better understood with the aid of

from the following description of an embodiment

  preferred but not limiting shown in the accompanying drawing in which the single figure shows a diagram of an installation for implementing the method according to the invention for supplying a fuel in fine grains

to a gasifier.

  We have very schematically represented a

  zeifier 10 and a pressure tank 11. The re-

ference 12 designates fine-grained coal

  in bulk in the pressure tank.

Reference 13 designates the transport gas supply pipe provided with a valve 14 on which an instrument 26 acts to regulate the flow of gas passing through it. Reference 15 designates the pipe for supplying pressure maintenance gas. This conduct

contains a valve 16. The coal is transported from the

  pressurized service 11 to the gasifier 10 by a

driving 17.

The pipe section 13 and the trans-

  port 17 are connected by a pipe 18 crossing the

pressure tank 11. In this line, inside

  inside the bulk 12, there is provided a closing device 19 which is arranged so that in its open position, the fine-grained fuel

from bulk 12 arrives in the con-

  pick 18 and therefore in the conduct of trans-

port 17.

The reference 20 designates a device which is connected on the one hand to the pressure tank 11, via the line 21, and on the other hand to the gasifier 10, via the line 22, and which measures the difference in Dression between these two devices. This pressure difference represents a measure of the amount of fine grain material

transported in line 17. The amount of

tible supplied to the gasifier 10 per unit of time determines the pressure difference measured in the

device 20. To maintain the amount of

constant target, it is necessary to maintain the diff

  pressure reference between the gasifier and the tank

see under pressure at a determined value. This va-

their pressure difference is applied to the a-

setpoint corrector 23. The devices and 23 act on the regulating member 24. This determines the differences between the actual value measured by the device 20 and the setpoint, and acts, by means of the line 25, on the valve 16 and consequently on the supply of the holding gas

  pressure in a direction such that the difference in pressure

between the pressure tank and the gasification

  tor returns to the predetermined value and therefore

quent, the quantity of fine grain fuel supplied to the gasifier through line 17 has the predetermined value.

  We see that this type of regulation of the functioning-

  the gasifier is very simple and does not require

than simple devices.

Claims (2)

  1. Method for controlling a device for the pneumatic transport of fine-grained fuel to a gasifier, the transport gas and a pressure-maintaining gas being introduced into a pressure tank provided with an airlock device and   leading the fuel to the gasifier through the   transport pipe medium, characterized in that the regulation of the quantity of fuel supplied to the gasifier is effected by means of a device which measures the difference between the pressure in the transport tank and the pressure reqnant in the gasifier.   2. Method according to claim 1, character- in that the regulation is carried out by modifying the flow rate of the gas for maintaining the pressure introduced in the transport tank.