Smoke tube

An evaluation of the HVAC system may include limited measurements of temperature, humidity, air flow, as well as smoke tube observations. Complex investigations may require more extensive or sophisticated measurements of the same variables (e.g., repeated COj measurements taken at the same location under different operating conditions, continuous temperature and relative humidity measurements recorded with a data logger). 

TTie ability of the ventilation system to protect the worker efficiently can readily be determined by personal samples. The PIMEX method (see Chapter 12) can be used to determine the worker s exposure during various work phases. The capture efficiency as well as the supply air fraction can be measured using tracer gas techniques. Simple evaluation is carried out visually with smoke tube or pellet tests. Daily system evaluation is recommended using airflow or static pressure measurements at appropriate parts of the system. The air velocities, turbulence intensities, air temperature, mean radiant temperature, and air humidity should also be measured to provide an assessment ol thermal comfort. 

This is a clear liquid that vaporizes and, on contact with damp air, combines with w ater to produce a dense acid mist. Titanium tetrachloride can be painted on to surfaces, such as fume cupboard sills, from which it will evaporate over a period of several seconds showing the airflow patterns close to the surface. (Airflow patterns close to a surface could also be visualized by fastening short filaments of wool or cotton to the surface). Titanium tetrachloride can also be used, when soaked onto a cotton swab, in a similar way to a smoke tube. It is a simple and inexpensive method but the production of smoke, which is toxic and corrosive, is uncontrollable. 

Smoke tube A tube or a canister containing a smoke-generating chemical used to observe air movements within a room. 

In calculating the smoke tube inlet gas temperature of a shell boiler, A includes the effective water-cooled surface in the reversal chamber. In coal-fired boilers, any water-cooled surface below the grate is excluded from A. 

Room overpressure can conveniently be tested during this period. Produce a single line sketch of the conditioned space(s) including doorways. Test for air-flow direction with hand smoke tubes, both at the top and bottom of closed doors, and record the direction of flow. Crack the doors open if fully sealed. 

The hot combustion gases were directed through the heat exchanger tubes, and to this day FT boiler combustion gas tubes continue to be variously called fire tubes, smoke tubes, flue gas tubes (or simply tubes). 

FB boilers are similar to SM boiler designs except that, instead of a fully immersed furnace tube, they have a bottom furnace (with a crowned combustion chamber) that sits on a refractory floor. Two-pass fire tubes (smoke tubes) connect the combustion chambers to the gas exit vent (smoke stack). 

Both types of boiler systems may incorporate finned copper heating coils, which are located above the furnace and gas-pass tubes (smoke tubes or fire tubes) and provide for indirect heating of domestic HW. Where coils are fitted and the boilers are only fired during winter months, domestic HW heating usually is provided via gas heaters for the summer. 

The pith was used by Native Americans as a moxibustion sort of treatment, where the herb is burned to cause heat on a particular part of the body. Modern-day biologists still use elder pith to hold scientific specimens as it can easily be sliced. The pith has also been used for electrical experiments and in toy making. The hollowed elder stalk has also been used as a smoking tube, especially for the inhalation of specific herbal medicines in both early America and Europe. 

Generate smoke for 1 to 2 minutes and shut off the smoke tube... 

Equipment Selection. Choose direct and indirect reading instruments that address each parameter identified in the preliminary sampling strategy. Select equipment that is accurate, reliable and durable. Air velocity measuring equipment and smoke tubes should be included for the evaluation of exhaust ventila-... 

The direction of flow must be into the enclosure as demonstrated by a device such as a smoke tube. 

Type-smoke tube type/water tube type Specifications of tubes (type, ID, OD, length, composition)... 

This qualitative fit test uses a person s response to the irritating chemicals released in the smoke produced by a stannic chloride ventilation smoke tube to detect leakage into the respirator. 

Only stannic chloride smoke tubes shall be used for this protocol. 

The test operator shall break both ends of a ventilation smoke tube containing stannic chloride, and attach one end ofthe smoke tube to a lowflowairpump set to deliver 200 milliliters perminute,oran aspirator squeeze bulb. The test operator shall coverthe other end ofthe smoke tube with a short piece of tubing to prevent potential injury from the jagged end of the smoke tube. 

The test operator shall direct the stream of irritant smoke from the smoke tube toward the face sealareaofthe testsubject,using the low flow pump or the squeeze bulb. The testoperator shall begin at least 12 inches from the facepiece and move the smoke stream around the whole perimeter of the mask. The operator shall gradually make two more passes around the perimeter of the mask, moving to within six inches of the respirator. 

Each test subject passing the irritant smoke test without evidence of a response (involuntary cough,irritation)shallbegivenasecondsensitivity screening check, with the smoke from the same smoke tube used during the fit test, once the respirator has been removed, to determine whether he/she still reacts to the smoke. Failure to evoke a response shall void the fit test. 

Type of boiler required—water-tube type or smoke-tube (fire tube) type ... 

A coal-, oil-, or a gas-fired boiler will not be a WHRB. It will need separate air pollution control systems such as dust separators, electrostatic precipitators, induced draught fans, and a tall chimney for the exit gases from the boiler. Comparison of water-tube and smoke-tube boilers. 

Type of boiler required—smoke tube (preferable for process heating) or water tube if specially required by the plant management,... 

Smoke tubes are hand-held pumps that disperse smoke or powder visible to the eye. One can watch the movement of the smoke to see what movement patterns exist in a space or near an exhaust hood. Smoke-producing candles work the same way to aid observation of air movement. 

The constmction should be done as per Statutory Rules of Codes and Standards MOC and size of ferrules offered by vendor for protecting tube sheets (for the smoke-tube side). 

Oil fired/water tube boilers take less time as compared to coal fired/smoke tube boilers)... 

Air flow patterns can be shown by tracers from smoke tubes which produce a plume of smoke when air is puffed through them (Figure 21.6). For workplaces where airborne particles are released it is possible to visualise the movement of the particles by use of a dust lamp. This shines a strong parallel beam of light through the dust cloud highlighting the particles in the same way that the sun s rays do. 

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