Gas-Fired Furnace Settings

Kitmondo 06 May 2014

This article first appeared in Practical Engineering 1940 Vol1 No2. The article is therefore correct as of 1940. The article discusses new types of equipment launched onto the market at the time.

For the gas-firing of furnace settings in the engineering, general metallurgical, and many other industries, using producer gas, coke-oven gas, town gas, blast-furnace gas, or any other type of gas, whether clean or dirty, and whether using cold or preheated air, much interest attaches to the "Gako" turbulent burner produced by Liptak Furnace Arches, Ltd., of London (temporary war address: "Max Welton," Boltro Road, Haywards Heath, Sussex). Several new designs have been produced, and the complete range available covers almost every known condition of gas-firing at a rate within the range of 300-300,000 cubic feet per burner per hour.

The basic principles of all the designs are the same, consisting of low-pressure operation, generally 2- 4in. water gauge, independent valve or equivalent control of the gas and air supply, and the passage of the gas or the air (and in many of the modifications, of both together) through the burner in alternate thin layers or streams, which are given a pronounced whirling motion by means of spiral guides or passages. The air is supplied under pressure (forced draught), or taken through the burner by the natural draught of the setting.

High Combustion Efficiency

As a result of the very rapid and intimate mixing of the gas and air, the flame is of the short, soft and "globular" variety, with no stratification and “cutting“ action representing also high combustion efficiency. Further, because of the accurate control, the flame may be oxidising, neutral, or reducing as required, and is equally suitable for low or high-temperature work. There is also no formation of an explosive mixture in the burner, since the air and the gas do not mix at this point, and consequently the flame can be turned down to the extent of 90 per cent, without any danger of a blow-back.

In all cases a front cover in the casing can be removed or opened, giving full access to the burner for cleaning or repairs, without interfering with the pipe circuits, whilst no moving parts of any kind are used.

A Multi-Tube Burner

A notable example of these burners is the new "T.B." pressure type, used for furnaces of larger size with ample space, which is on the multiple-tube principle, the gas and air being split up into a number of separate streams, each of which is given a whirling motion. One of the most valuable features is the provision of a large refractory block with a series of longitudinal parallel channels or passages, fixed in the combustion chamber to protect the burner from the heat.

Equally interesting is the "Gako W.B." high-efficiency diffused flame forced-draught type, used for small furnaces. In this case, the air under pressure enters by way of an inlet pipe at the top and passes through a renewable centre nozzle having internal vanes to give the powerful whirling motion, whilst the gas travels from an inlet pipe at the bottom through an outer annulus at the mouth of the burners, where complete and very rapid mixing with air takes place. The design is particularly suitable for- dirty producer gas or blast furnace gas, and if necessary, the air and gas control valves on the inlet pipes can be connected by link-work for simplicity of control.