FIELD OF INVENTION

The present invention relates to a constant feed gasifier.

More particularly, the invention relates to a constant feed gasifier adapted to be operated by means of bio-fuel.

BACKGROUND TO INVENTION

Gasification technology has been used since the mid-19 ^th century in particular for illumination. Presently gasification is the main technology for biomass conversion to energy and an attractive alternative for the thermal treatment of solid waste. The number of different uses of gas shows the flexibility of gasification and therefore allows it to be integrated with several industrial processes, including power generation systems. The use of a waste-biomass energy production system is also an important part. Unfortunately the known gasification systems using waste-bio mass and other bio-fuel are not very efficient and economical.

It is an object of the invention to suggest a constant feed gasifier which will assist in over-coming the aforementioned problems.

SUMMARY OF INVENTION

According to the invention, a constant feed gasifier includes (a) a floating combustion chamber; (b) a hopper including a conveyer belt system adapted to provide bio-mass material to the floating combustion chamber; and

(c) an internal heat exchanger associated with the combustion chamber.

In order to achieve the best thermal efficiency of the constant feed gasifier, the combustion chamber may be mounted on one or more load cells and/or limit switches.

In order to achieve a constant gasification process, the weight of the bio-material may be weighed in by the load cells.

The load cells may determine a pre-set minimum and maximum weight of the bio- material.

When the combustion chamber reaches a minimum weight the load cells may switch the conveyer belt on via a controller, the conveyer belt will then feed the bio mass into the combustion chamber until it reaches its maximum weight set point.

When the combustion chamber reaches a maximum weight the load cells may switch the conveyer belt off.

As the combusting process is converted into gas and thermal energy, the bio-mass inside the combustion chamber may get less, until it reaches its minimum set point whereby the conveyer belt will be switched on again by the load cells or limit switches, and the process may repeat itself.

The combustion chamber may be relatively small.

The right amount of steam and oxygen for a particular amount of bio-mass may be injected into a much smaller combustion chamber. The small combustion chamber may then produce very high temperatures for a smaller amount of bio-mass, creating extremely high temperatures of 1200 °C plus, which will provide an extremely high efficiency with a minimum char content.

This process may then continue due to load cells or limit switches that will only provide the right amount of bio material.

BRIEF DESCRIPTION OF DRAWINGS

The invention will now be described by way of example with reference to the accompanying schematic drawings.

In the drawings there is shown in

Figure 1 : a perspective view of a constant feed gasifier according to the invention;

Figure 2: a first side view of the constant feed gasifier as seen along arrow II in

Figure 1 showing the combustion chamber;

Figure 3: the constant feed gasifier shown in Figure 2 but with the combustion chamber covered;

Figure 4: a third side view of the constant feed gasifier as seen along arrow IV in

Figure 1 ; and

Figure 5: a diagram showing the various components of the constant feed gasifier shown in Figure 1 . DETAILED DESCRIPTION OF DRAWINGS

Referring to the drawings, there is shown a constant feed gasifier, generally indicated by reference numeral 10, in accordance with the invention.

The constant feed gasifier includes

(a) a hopper 1 1 including a conveyer belt system 4;

(b) a floating combustion chamber 9; and

(c) an internal heat exchanger 5.

The other components of the constant feed gasifier 10 are the following:

(a) 1 a+1 b: load cells or limit switches;

(b) 2: Air and steam injectors;

(c) 3: Blower or compressor or high pressure steam generator;

(d) 6: outer shell;

(e) 7: High temperature insulation; and

(f) 8: Stack.

The combustion chamber 9 should be near-perfect to be able to get the maximum efficiency out of the constant feed gasifier 10.

In order to achieve the best thermal efficiency of the constant feed gasifier 10, the combustion chamber 9 is mounted on one or more load cells and/or limit switches 1 a+1 b.

In order to achieve a constant gasification process, the weight of the bio-material is weighed in by the load cells 1 a+1 b. The load cells 1 a+1 b determine a pre-set minimum and maximum weight of the bio- material.

When the combustion chamber 9 reaches a minimum weight the load cells 1 a+1 b switch the conveyer belt 4 on via a controller, the conveyer belt 4 will then feed the bio mass into the combustion chamber 9 until it reaches its maximum weight set point.

When the combustion chamber 9 reaches a maximum weight the load cells 1 a+1 b switch the conveyer belt 4 off.

As the combusting process is converted into gas and thermal energy, the bio-mass inside the combustion chamber 9 gets less, until it reaches its minimum set point when the conveyer belt 4 will be switched on again by the load cells or limit switches 1 a+1 b, and the process repeats itself.

The combustion chamber 9 is relatively small.

A big advantage is the constant feed of the bio-mass.

Another advantage of this floating combustion chamber 9 is that by having the right amount of bio-mass per kg, the right amount of steam and oxygen is injected into a much smaller combustion chamber 9. This small combustion chamber 9 can then produce very high temperatures for a smaller amount of bio-mass, creating extremely high temperatures of 1200 °C plus, which will provide an extremely high efficiency with a minimum char content.

This process is then continued due to load cells or limit switches 1 a+1 b that will only provide the right amount of bio material.