GB2129827A - Fuel briquette - Google Patents

Abstract

Fuel briquettes of high calorific value, which are clean and convenient to handle, are described. They are composed principally of paper and straw, preferably entirely of paper and straw. A suitable range for the dry weight content of the straw is 3 to 15%. Dye and/or an essence giving an attractive odour may be included. The briquette is formed by thoroughly mixing chopped straw with a paper pulp, shaping the mixture into the briquette, compressing it and then allowing it to dry. The presence of the straw assists the drying process because the straw leaves some air passages in the briquette.

Description

SPECIFICATION Fuel briquettes This invention relates to fuel briquettes, particularly briguettes suitable for use in domestic heating systems, particularly so-called "boilers", though the invention is not restricted to this use.

There is a considerable need for a cheap and clean solid fuel, which can be used as a substitute for or in combination with conventional fossil fuels. Wood is, at least in some areas, expensive and not in plentiful supply. It also does not have consistent burning qualities, and produces by-products which can contaminate a furnace.

According to the invention, I provide a fuel briquette composed principally of paper and straw. Minor amounts (up to 50% in total) of other combustible substances may be included, but in a preferred form the briquette is formed substantially entirely of paper and straw. Generally, I require at least 2% by weight of straw, a suitable range being 3% to 15%, a more preferred range being 3% to 10%. A particularly preferred ratio is 95% paper and 5% straw (these are dry weights).

The briquette may include other substances, for appearance or other cosmetic reasons, for instance a dye and/or an essence to give it an attractive odour, for instance, pine, heather or lemon essence.

To make the briquette I prefer to soak paper in water, stir it to form a paper pulp and then thoroughly mix chopped straw with the pulp.

In forming the paper pulp, a suitable ratio of newspaper to water is about 0.5 I water to 100 g newspaper (1 pint water per quarter Ib.

newspaper). The mixture is shaped into the briquette, compressed and then allowed to dry. The presence of the straw assists the drying process because the straw leaves some air passages in the briquette. The compression may be performed in a standard briquette press, for instance that made by Briketpresse of Denmark and marketed by The Watts Group of Companies, Reading. A suitable compression pressure is 1600 Ibs/sq.in (approx 11 x 103 kPa).

A typical weight of a dry briquette is 3409 (12 oz.), and typical dimensions are 25 x 9 x 7.6 cm (10 X 3+ X 3 ins.).

I prefer to use newspaper as the paper, since this form of paper can be cheaply available.

Briquettes of the invention have high calorific value, are clean and convenient to handle and have shown themselves to be well suited to domestic water heating systems. With a suitably controlled air supply, in a furnace, they burn at a sufficiently slow rate. For instance, a 1 2 oz. briquette as described above may have a burn life of 1-1+ hours with a heat output of 7500 Btu (approx.

8 x 10e J). It is smokeless when burning.

1. A fuel briquette composed principally of paper and straw.

2. A fuel briquette according to claim 1 which is formed substantially entirely of paper and straw.

3. A fuel briquette according to claim 1 or claim 2 which contains at least 2% by dry weight of straw.

4. A fuel briquette according to claim 3 in which the straw content is between 3 and 15% by dry weight.

5. A fuel briquette according to claim 4 wherein the straw content is in the range 3 to 10% by dry weight.

6. A fuel briquette according to any one of the preceding claims further containing a dye and/or an essence imparting an odour to the briquette.

7. A fuel briquette according to any one of the preceding claims which is formed by drying of a compressed body comprising a mixture of paper pulp and chopped straw.

8. A fuel briquette according to claim 1 substantially as herein described.

9. A method of making a fuel briquette composed principally of paper and straw comprising forming a paper pulp, thoroughly mixing chopped straw with the pulp, forming a shaped body from the mixture, compressing the shaped body, and effecting drying of the compressed shaped body, to form the dry briquette.

10. A method according to claim 9 wherein waste newspaper is used as the paper.

11. A method of forming a fuel briquette according to claim 9 substantially as herein described.

CLAIMS (17 Nov 1983) 1. A fuel briquette in the form of a dried compressed shaped body composed principally of paper and chopped straw.

7. A fuel briquette according to any one of the preceding claims which is formed by drying of a compressed body comprising a mixture of paper, water and chopped straw.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Fuel briquettes This invention relates to fuel briquettes, particularly briguettes suitable for use in domestic heating systems, particularly so-called "boilers", though the invention is not restricted to this use. There is a considerable need for a cheap and clean solid fuel, which can be used as a substitute for or in combination with conventional fossil fuels. Wood is, at least in some areas, expensive and not in plentiful supply. It also does not have consistent burning qualities, and produces by-products which can contaminate a furnace. According to the invention, I provide a fuel briquette composed principally of paper and straw. Minor amounts (up to 50% in total) of other combustible substances may be included, but in a preferred form the briquette is formed substantially entirely of paper and straw. Generally, I require at least 2% by weight of straw, a suitable range being 3% to 15%, a more preferred range being 3% to 10%. A particularly preferred ratio is 95% paper and 5% straw (these are dry weights). The briquette may include other substances, for appearance or other cosmetic reasons, for instance a dye and/or an essence to give it an attractive odour, for instance, pine, heather or lemon essence. To make the briquette I prefer to soak paper in water, stir it to form a paper pulp and then thoroughly mix chopped straw with the pulp. In forming the paper pulp, a suitable ratio of newspaper to water is about 0.5 I water to 100 g newspaper (1 pint water per quarter Ib. newspaper). The mixture is shaped into the briquette, compressed and then allowed to dry. The presence of the straw assists the drying process because the straw leaves some air passages in the briquette. The compression may be performed in a standard briquette press, for instance that made by Briketpresse of Denmark and marketed by The Watts Group of Companies, Reading. A suitable compression pressure is 1600 Ibs/sq.in (approx 11 x 103 kPa). A typical weight of a dry briquette is 3409 (12 oz.), and typical dimensions are 25 x 9 x 7.6 cm (10 X 3+ X 3 ins.). I prefer to use newspaper as the paper, since this form of paper can be cheaply available. Briquettes of the invention have high calorific value, are clean and convenient to handle and have shown themselves to be well suited to domestic water heating systems. With a suitably controlled air supply, in a furnace, they burn at a sufficiently slow rate. For instance, a 1 2 oz. briquette as described above may have a burn life of 1-1+ hours with a heat output of 7500 Btu (approx. 8 x 10e J). It is smokeless when burning. CLAIMS

1. A fuel briquette composed principally of paper and straw.

2. A fuel briquette according to claim 1 which is formed substantially entirely of paper and straw.

3. A fuel briquette according to claim 1 or claim 2 which contains at least 2% by dry weight of straw.

4. A fuel briquette according to claim 3 in which the straw content is between 3 and 15% by dry weight.

5. A fuel briquette according to claim 4 wherein the straw content is in the range 3 to 10% by dry weight.

6. A fuel briquette according to any one of the preceding claims further containing a dye and/or an essence imparting an odour to the briquette.

7. A fuel briquette according to any one of the preceding claims which is formed by drying of a compressed body comprising a mixture of paper, water and chopped straw.

7. A fuel briquette according to any one of the preceding claims which is formed by drying of a compressed body comprising a mixture of paper pulp and chopped straw.

8. A fuel briquette according to claim 1 substantially as herein described.

9. A method of making a fuel briquette composed principally of paper and straw comprising forming a paper pulp, thoroughly mixing chopped straw with the pulp, forming a shaped body from the mixture, compressing the shaped body, and effecting drying of the compressed shaped body, to form the dry briquette.

10. A method according to claim 9 wherein waste newspaper is used as the paper.

11. A method of forming a fuel briquette according to claim 9 substantially as herein described.

CLAIMS (17 Nov 1983) 1. A fuel briquette in the form of a dried compressed shaped body composed principally of paper and chopped straw.