Heating-surface sentence example
- To obtain a larger heating surface than a pipe affords, radiators are connected with the pipes where desired, and the water passing through them warms the surrounding air.
- Ventilating radiators are similar, but have an inlet arrangement at the base to allow external air to pass over the heating surface before passing out through the perforations.
- These results are brought about by adding to the cold juice as it comes from the mill the proper proportion of milk of lime set up at 8° B., and then delivering the limed juice in a constant steady stream as near the bottom of the defecator as possible; it is thus brought into immediate contact with the heating surface and heated once for all before it ascends, with the result of avoiding the disturbance caused in the ordinary defecator by pouring cold juice from above on to the surface of the heated juice, and so establishing down-currents of cold juice and up-currents of hot juice.
- Forgetful or ignorant of the great principle announced and established by Rilleux, they have mostly devoted their energies and ingenuity to contriving all sorts of complicated arrangements to give the juice the density required, by passing and repassing it over the heating surface of the apparatus, the saving of a few square feet of which would seem to have been their main object.
- But this competition among inventors, whatever the incentive, has not been without benefit, because to-day, by means of very simple improvements in details, such as the addition of circulators and increased area of connexions, what may be taken to be the standard type of multiple-effect evaporator (that is to say, vertical vacuum pans fitted with vertical heating tubes, through which passes the liquor to be treated, and outside of which the steam or vapour circulates) evaporates nearly double the quantity of water per square foot of heating surface per hour which was evaporated by apparatus in use so recently as 1885 - and this without any increase in the steam pressure.Advertisement
- All their endeavours have obtained at best but a doubtful success, for they have overlooked the fact that to evaporate a given weight of water from the syrup in a vacuum pan at least an equal weight (or in practice about 15% more) of steam must be condensed, and the first cost of mechanical agitators, together with the expenditure they involve for motive power and maintenance, must be put against the slight saving in the heating surface effected by their employment.
- So also the principles laid down by Howard with respect to the vacuum pan hold good to-day: larger pans have been made and their heating surface has been increased, but it has been found by practice now, as it was found then, that an ordinary worm or coil 4 in.
- Earthy matter and other matter precipitated and fallen on the copper double bottom may be dislodged by a slowly revolving scraper - say every twelve hours - and ejected through the bottom discharge cock; and thus the heating surface of the copper bottom will be kept in full efficiency.
- Portions can be added or taken away according to the amount of heating surface required.
- II) differs from the Whitwell (I) in having not a series of flat smooth walls, but a great number of narrow vertical flues, E, for the alternate absorption and emission of the heat, with the consequence that, for given outside dimensions, it offers about one-half more heating surface than the true Whitwell stove; and (2) in that the gas and the blast pass only once up and once down through it, instead of twice up and twice down as in the modern true Whitwell stoves.Advertisement
- The "D" form is mostly adopted owing to its power of retaining its shape after long exposure to heat, and the large amount of heating surface it presents at its base.
- The heating surface is the underside of hollow, rotating cones.
- the engines of a 10-ton steam crane have cylinders capable of indicating about 60 horse-power when working at full speed, but it is found that, in consequence of the intermittent working, sufficient steam can be supplied with a boiler whose heating surface is only a to 4 of that necessary for the above power, when developed continuously by a stationary engine.
- These results are brought about by adding to the cold juice as it comes from the mill the proper proportion of milk of lime set up at 8Ã‚° B., and then delivering the limed juice in a constant steady stream as near the bottom of the defecator as possible; it is thus brought into immediate contact with the heating surface and heated once for all before it ascends, with the result of avoiding the disturbance caused in the ordinary defecator by pouring cold juice from above on to the surface of the heated juice, and so establishing down-currents of cold juice and up-currents of hot juice.