Document oMMEpbnaYwOZJB5zLzrYw1qN7

i ji II ii i i n ifo&dlaitwiQ CEMENT Even an unskilled laborer does a good job--speedily--with B-H No. 1 Cement. This unique prod uct sticks instantly--on any sur face; no sliding off or rolling up behind the trowel; no droppings when applied to under-surfaces. You get a neat, workmanlike job every time--without trouble and without waste. B-H No. 1 Cement brings you many other advantages. Because its basis is black Rockwool--high in resistance to both heat and moisture--it resists temperatures up to 1800 F.--even under the most humid conditions. Because it contains a special rust-inhibitor, it safeguards metal from corrosion and assures a per manent bond. Because its calcium content is low, its silica content high, it does not disintegrate. B-H No. 1 Cement can be stocked without breakage or loss and is reclaimable up to 1200 F. Thus it is in every way practical for maintenance work--especially for valves, fittings and irregular surfaces, large or small, and as a finish over blanket and block in sulations. The coupon below will bring you full information and a practi cal sample of B-H No. 1 Cement. Baldwin*Hill pressures and temperatures, and turbi size. In the absence of. more acc data assume an increase of 13% for load and 45% for quarter load. If full-load steam rate is 23.4 lb a kwhr, 3413 4- 23.4 = 145 Btu per k' But 5% is lost in bearing and generatoi hence 115.4- 0.95 = 153 Btu to be ta out., of the steam. Subtracting this fi 1319 we have 1166, which Is the resof' obtained from the MoIIier diagram. For half load the computation is js follows: 23.-txl.13 = 26.1 lb per kwhr 3413 1 -r-fT>2--.4r X v- .yr,u~z -- 143 Btu used in turbine 1319 -- 143 =3 1176 Btu, enthalpy in exhausti This point on the diagram shows ji deg superheat. Since the enthalpy fa? 34.7 psia, saturated, is 1167, the diffeif ence of 9 Btu has gone into superheat giving 18 deg. If there must be no sapep heat in the exhaust at half load, install a desuperheater or reduce the throttle superheat by about 18 deg. This gives about 1% moisture in the exhaust il full load, but no superheat at half load A line connecting throttle and exhaust points shows the steam condition at any' pressure during expansion. To bleed at 50 psi (64.7 psia) we find by the inters, section of the pressure line with the coat dition lines that there is 40 deg. supegi heat at full load and 56 at half load. Steam rate of a bleeder, or extraction turbine is about 3% higher than of out designed for no extraction. For more accurate temperature estimates at ef traction points draw a new condition lit for the higher steam rate. We have had to omit a large number of refinements in this explanation. Some are covered in the turbine section ot Dec 1945 Power. Turbine efficiencies, vary with size, load, throttle pressure an<f temperature, and exhaust pressure, all of which must be included in such caF dilations as multistage feedwater heat; ing. We are interested in safe exhaust temperatures and these approximations give the temperatures within about 1, deg, which is as much accuracy as l*. needed. Jr Comments on Reducing Valve SPECIALISTS IN THERMAL INSULATION PRODUCTS 8a!dwin-Hill Co., 540 Klagg Ave., Trenton 2, N. J. Send information on products checked below: I | Free sample of B-H No. 1 Cement No. 100 Pipe Covering--effective up to 1200 F. (for long runs overhead, underground, Diesel exhausts) __ 1 Mono-Block--the one-block insula'jon for a11 temperatures up to 1700 F. __ Black Rockwool Blankets (felted between various types of metal fabrics) By these methods the designer wilj. -elect such a steam pressure and te;. perature that the steam can generate afl electrical power the factory needs. At, some electrical loads there will not bg enough exhaust -team to meet the fa| ^pressure, 162 166a i o tha|rcy of eigi A reducing valve that is always POWER January I?*4