Auxiliary heaters

In 1909 one company began selling solar water heaters with separate collectors and insulated storage tanks. The collectors were made of copper tubing soldered to a copper plate in a glass covered box. The hot water was transferred to the storage tank by thermosyphon action, so the insulated tank had to be installed above the collector, typically in the attic or on the roof It was often connected to an auxiliary heater on the stove or furnace to supplement solar... 

The basic fluid-bed unit consists of a refractory-lined vessel, a perforated plate that supports a bed of granular material and distributes air, a section above the fluid bed referred to as freeboard, an air blower to move air through the unit, a cyclone to remove all but the smallest particulates and return them to the fluid bed, an air preheater for thermal economy, an auxiliary heater for start-up, and a system to move and distribute the feed in the bed. Air is distributed across the cross section of the bed by a distributor to fluidize the granular solids. Over a proper range of airflow velocities, usually 0.8-3.0 m/s, the solids become suspended in the air and move freely through the bed. 

The bottom and top auxiliary heaters can be used to decrease the temperature gradient across the specimens. Since temperature measurements are taken under steady state heat... 

The technique has also been demonstrated with a single specimen. In that case, one of the cold plates is removed and the auxiliary heater on that side is heated to match the temperature of the metered area. Since no temperature gradient exits in that direction, heat generated from the metered area flows uniaxially through the single specimen. 

The B2 exhaust fires a steam generator, auxiliary heaters, and water recovery equipment. The exhaust from methane oxidation is steam laden. 

In operation, it is essential that the column be set exactly vertical, that the support be free from vibration, and that it be in a draft-free location. The column is almost invariably vacuum-jacketed, with an auxiliary heater on the outside of the jacket, which is maintained... 

Fabric filters are widely used owing to their simplicity, reliability, efficiency and competitive capital cost. Their application is limited by both the humidity and the temperature of the gas streams. Condensation or collection of water droplets of the filter fabric wilt lead to blinding of the cloth. Normal fitter cloths can operate up to 180 °C and fibreglass fabric can operate up to 250 °C. Where the limitation of humidity or temperature is likely to be a problem, precautions must be taken (such as the use of gas to air heat exchangers, the addition of cooling air/water, or the use of auxiliary heaters), or an alternative collection system must be sought. 

Automatically Controlled Solar Dryer with Auxiliary Heater.342... 

Switch in and out devices (e.g., fans, humidifiers, valves or dampers, auxiliary heaters) when the limit values of some parameters occur... 

The remaining heating reqrtirement mrrst be supphedby an auxiliary heater, based on some form of comerrtiorral... 

Gas- or oil-fired heaters can also be used as auxiliary heat sources, but these would be external to the tank, circulating its content through the heater or having a separate heat transfer loop to supply heat to the hot water tank through a heat exchanger. From the point of view of environmental sustainability gas auxiliary heaters are much preferred as they cause much less CO2 emissions. 

FIGURE 10 Three ways of coupling an auxiliary heater with the solar space heating system (1) In the storage tank, (2) in the distribution circuit flow pipe (series connection), and (3) In a storage bypass (parallel connection). 

Auxiliary heaters operating on oil firing are also employed to heat the gases if required. In certain cases, additional sulfur is fed in to increase the SO2 concentration (for evolution of more heat during conversion of SO2). 

C or at least 20°C above the dewpoint, whichever is greater, in order to avoid moisture condensation within the filter. An auxiliary heater may be used to increase the off-gas temperature however, the maximum allowable filter temperature specified by the manufacturer for permanent operation must be taken into consideration if an auxiliary heater is used. 

The ASTM- (or DIN-) standard method for low conducting solid material (X" ) is the two plate method with an electrical main heater between two cylindrical sample plates having a small length to diameter ratio and two heat sinks as well as a cylindrical guard heater (Figure 2). For better temperature control each heat sink consists of an electrical driven auxiliary heater and a water cooler. In this case the heat flow rate to each of the two samples is given by... 

Any visual leaking of lubricant (i.e., engine supplied oil pressure) from electrical component such as alternator, auxiliary heater, etc. (396.5(b))... 

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