There are a wide variety of venturi burner styles. Basic burners without flame safety and fully optioned burners with safety, preheat pilots, pressure gauges and auto ignition. Comprehensive price lists can be emailed or faxed. Simply contact us.
INSTALLING AND ADJUSTING THE KILN BURNERS
The actual firing position and direction should be determined before installation, check the following "Kiln Floor Plan" sheet for some ideas.
For safe and efficient operation, it is important to follow these guidelines:
The burner tip should be mounted approx. 20mm away from the kiln port face. The safety probe should not be sited near the hot surface of the burner port. A small amount of "secondary" air is necessary to complete combustion and this must be available around the burner tip. Never place the burner tip inside the kiln port. The burners should be rigidly mounted to the kiln frame or the floor if the kiln is securely fixed to the ground. The tips must fire centrally into the burner port. The usual method is to use pipe type clips.
A suitably qualified person must undertake the gas connection to the kiln. It is important to ensure the gas supply is adequate for the amount of heat required. The gas fitter will size the pipe according to the total loading ie. the total BTU/HOUR or MJ/HOUR. You can calculate this from the sizing chart. Make sure all joints are checked for leaks with soapy water or a manometer prior to a start.
There are critical points in the firing when the atmosphere will affect the clay body and the glaze and to obtain the best results you should have a thorough understanding of the process. Until you wish to experiment during the firing the most efficient setting for the atmosphere is neutral unless you wish to produce a reducing or oxidising atmosphere.
BURNER PORT SIZE
The size of the port depends on the amount of excess air required for the type of firing and the height of the flue or chimney. A reasonable guide is approx. 20mm bigger in diameter than the burner tip. The higher the flue, the greater the draw and the smaller the port. The optimum port shape is a round hole with a 15o taper but with venturi burners this is not critical as the venturi burner inspirates most of the air required for combustion through the venturi throat.
FLUE SIZE AND HEIGHT
A long flue with an excessive draw is not as important for gas kilns as it may be for wood firing kilns but it is important to ensure the waste gasses exit from the workplace. A canopy is usually constructed and this is positioned above the flue termination and also serves a dual purpose by diluting the gasses. A tile can be set on this outlet for reduction but should be restricted from completely closing as a dangerous situation can occur. The actual size of the flue is dependent on many factors and the usual method is to oversize slightly and reduce accurately with the damper. A good guide is 1 square inch per 8,000 BTU.
The primary air can be increased or decreased by controlling the rotating shutter. Closing the shutter will reduce the amount of air available to mix with the gas and will produce a gas rich or reducing flame. Opening the air shutter will create an oxidising or air rich flame.
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