JPH0356274B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for stably supplying powdered coal to a coal gasifier.

The use of lock hoppers in coal gasification plants to feed coal to the gasifier under pressure is well known.

In the conventional technology, at the lock hopper exit part,
Equipped with rotary valve and screw feeder,
This allows for a fixed supply of coal. In such conventional technology, since the coal is mechanically dispensed, the amount of coal dispensed varies depending on the level of coal in the hopper, coal entanglement with the screw feeder, etc. I ended up
It was extremely difficult to supply a stable amount. Furthermore,
Measuring the amount of coal supplied relies on measuring the rotational speed of a rotary valve or screw feeder, which has the drawback of not being able to accurately detect the amount of coal supplied.

If the amount of coal supplied to the coal gasifier is not constant, it causes changes in the gasifier load and has a large negative impact on the stable operation of the gasifier, but this problem has not been solved with conventional technology. be.

The object of the present invention is to overcome such drawbacks in the prior art and to provide a method for stably supplying coal in a lock hopper to a coal gasifier.

To summarize the present invention, the present invention supplies inert gas into the lock hopper to fluidize the coal in the hopper, makes the pressure inside the lock hopper higher than the pressure inside the gasifier, and transfers the coal from the lock hopper to the gasifier. The amount of coal supplied is detected by measuring the pressure loss between the rock hopper outlet and the gasifier inlet in the coal supply piping that connects the rock hopper and the gasifier. The feature is that the pressure inside the lock hopper is adjusted with respect to the pressure inside the gasifier according to the amount of coal supplied.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a system diagram for explaining a method for stably supplying coal from a lock hopper to a gasifier, which is an embodiment of the present invention.

Powdered coal is supplied to the coal hopper 1 through a coal inlet 8. The coal in coal hopper 1 is then sent to coal supply hopper 2. Inert gas is supplied to the coal supply hopper 2 via a pressurizing gas supply pipe 12 and is pressurized to a predetermined pressure. The pressurized gas is sent to the lock hopper 3 downstream, and the coal in the coal supply hopper 2 is supplied to the lock hopper 3 together with this gas. Inert gas is supplied to the lock hopper 3 through a fluidizing gas supply pipe 7, and thereby the coal in the lock hopper 3 is fluidized. The pressure difference between the lock hopper 3 and the gasifier 4 can be adjusted to a desired value using a differential pressure regulator 5 and a pressure control valve 11, and inert gas for pressurizing the lock hopper 3 is supplied through a pressurizing gas supply pipe. 14. The coal discharged from the lock hopper 3 is conveyed to the gasifier through the coal supply pipe 15, but the gas for this conveyance is introduced from the coal conveyance gas supply pipe 10 which is connected to the coal supply pipe 15. be done. Preferably, the coal supply pipe 15 at the outlet of the lock hopper 3 is in the form of a bench lily 13. Thus, the coal supply pipe 15 is adapted to supply coal to the gasifier in an airflow state. The pressure loss in the coal supply pipe 15 between the outlet of the lock hopper 3 and the inlet of the gasifier 4 is measured by a differential pressure gauge 6. Since a change in the coal flow rate within the coal supply pipe 15 appears as a change in pressure loss, the measured value of the differential pressure gauge 6 indicates the amount of coal supplied within the coal supply pipe 15. In order to increase the amount of coal supplied, the differential pressure regulator 5 and pressure control valve 11 between the lock hopper 3 and the gasifier 4 are adjusted, and a large amount of gas is supplied to the lock hopper 3 via the pressurizing gas supply pipe 14. If the coal is introduced into the gasifier and pressurized, the amount of coal supplied to the gasifier 4 will be increased.
In order to reduce the amount of coal supplied, the process opposite to that described above may be adopted. Such control may be performed manually, and the differential pressure regulator 5 and the pressure regulating valve 11 may be manually adjusted by constantly monitoring the differential pressure gauge 6. It is clear that it is also possible to perform automatic control to automatically open and close 11. Since fluidizing gas is always supplied into the lock hopper 3 from the fluidizing gas supply pipe 7, the coal in the lock hopper 3 is always floated and fluidized. Therefore, regardless of the amount of coal in the lock hopper 3, the amount of coal discharged from the lock hopper 3 is determined by the pressurizing gas supply pipe 14.
This means that it can be controlled depending on the amount of pressurized gas supplied via the . It should be noted that the provision of a vent line 9 communicating with the coal supply hopper 2 and lock hopper 3 will be understood at a glance from FIG.

Since the present invention has the configuration as described above,
The amount of coal discharged from the Lothu hoppa does not change depending on the coal amount level in the Lothu hoppa, and by constantly fluidizing the coal in the Lothu hoppa, the coal is stably transferred from the Lothu hoppa to the gasifier. This has the useful effect of eliminating gasifier load changes and stably operating the gasifier.

[Brief explanation of drawings]

FIG. 1 is a system diagram for explaining a method for stably supplying coal from a lock hopper to a gasifier, which is an embodiment of the present invention. 1...Coal hopper, 2...Coal supply hopper, 3
... Lock hopper, 4 ... Gasifier, 5 ... Differential pressure regulator, 6 ... Differential pressure gauge, 7 ... Fluidization gas supply pipe, 8 ... Coal inlet, 9 ... Vent line, 10
... Gas supply pipe for coal conveyance, 11 ... Pressure adjustment valve, 12 ... Gas supply pipe for pressurization, 13 ... Bench lily, 14 ... Gas supply pipe for pressurization, 15 ... Piping for coal supply.

Claims (1)

[Claims] 1. A method for stably supplying a predetermined amount of pulverized coal from a rock hopper in which pulverized coal is stored to a coal gasifier by air flow conveyance, the method comprising: a means for fluidizing the coal in the rock hopper; means for maintaining the pressure of the fluidized rock hopper higher than the pressure of the coal gasifier; a coal falling amount adjustment valve provided at the coal outlet section at the bottom of the rock hopper; means for airflow conveying to the gasification furnace via the coal supply piping, and changes in the amount of coal supplied airflow to the gasification furnace through the coal supply piping are reflected in changes in pressure loss occurring within the coal supply piping. A stable coal supply method using a lock hopper, characterized in that the pressure in the lock hopper is adjusted according to the detected change in pressure loss, and the amount of coal supplied to the gasifier is controlled to a set value. .