Section 27-875. Charging chutes for refuse reduction

Charging chutes shall
  be constructed in accordance with the following requirements:
    (a) Directly connected. When  directly  connected  to  the  combustion
  chamber  of  an  incinerator,  the chutes shall be gas tight with smooth
  linings and shall conform to the following:
    (1) They shall be constructed in accordance with the requirements  for
  medium temperature chimneys.
    (2)  They  shall  extend  through the building roof and be open to the
  outer air. The opening shall be equal to the required chute size at  the
  top floor.
    (3)  If  a  roof  damper  is  used  it  shall  be  constructed to open
  automatically under conditions of excessive pressure or temperature. The
  roof  damper  shall  be  electrically  interlocked  with  the  auxiliary
  burners.
    (4)  Each  charging  chute  shall be provided with a spark arrester of
  corrosion resistive, noncombustible construction in  which  the  maximum
  size  of  mesh  opening  shall not exceed three-quarters of an inch. The
  cross-sectional free area of such arrester shall be not less  than  that
  of  the  inside  of the chute to which it is attached. The height of the
  spark arrester shall be such that there will be a minimum of twenty-four
  square feet of total free area provided for  a  chute  height  to  sixty
  feet;  thirty-six  square feet for a chute height from sixty-one feet to
  one hundred twenty feet; and forty-four square feet  for  chute  heights
  over  one  hundred twenty feet. In no case, however, shall the height of
  the spark arrester be less than one foot.
    (5) Provisions shall be made for sterilizing  the  charging  chute  by
  heating  or  purging  at  a temperature of at least four hundred degrees
  Fahrenheit but not higher than one thousand degrees Fahrenheit.
    (b) Not directly connected. When not directly connected to a  building
  service  incinerator,  the chutes shall be gas tight with smooth linings
  and shall conform to the following:
    (1) They shall  be  constructed  in  accordance  with  the  applicable
  requirements  for  shafts  in  table  3-5  and  subchapter  five of this
  chapter.
    (2) They shall extend through the building roof and  be  open  to  the
  air.  The opening shall be equal to at least one square foot.
    (3)  If  a  roof  damper  is  used  it  shall  be  constructed to open
  automatically under conditions of excessive pressure or temperature.
    (4) Provisions shall be made for sterilizing the  chute  by  spraying,
  washing, or other equivalent means.
    (5)  Bins,  containers,  or  rooms  for  receiving  rubbish  shall  be
  constructed as  required  by  section  27-837  of  article  eighteen  of
  subchapter  fourteen of this chapter and sprinklers shall be provided as
  required by the construction provisions of subchapter seventeen of  this
  chapter.
    (c) Sizes.
    (1)  The  sizes  of  chutes  directly connected to the incinerators in
  buildings shall conform to table 15-9.
    (2) Charging chutes not directly connected to  the  incinerator  shall
  have a cross-sectional free area adequate for the service intended.
    (d)  Charging doors. Charging doors, service openings, or hopper doors
  for chutes may be located in separate rooms or compartments enclosed  in
  non-combustible  walls or partitions, floors, and ceilings having a fire
  resistance rating of at least one hour and a self-closing fire door with
  a three-quarter-hour fire-protection rating. Service openings shall,  in
  no  case, have a free area of more than one-third of the cross-sectional
  free area of the chute to which they  give  access.  All  such  openings
  shall  be  substantially constructed of steel or the equivalent metal of

  sufficient thickness to prevent distortion or  other  damage  in  normal
  usage.  The  door shall be provided with counterweights, door checks, or
  other equivalent means for automatically closing after use and where the
  chute is connected directly to the combustion chamber of an incinerator,
  the  door shall be so constructed that the chute is closed off while the
  hopper is being loaded. No part of the door shall project into the chute
  at any time. The minimum height  of  charging  door  openings  shall  be
  eleven inches, and the minimum width shall be thirteen inches.
    (e)  When  charging  chutes  are  located  in  multiple  dwellings, in
  addition to the requirements of this subchapter,  the  chutes  shall  be
  constructed  in  accordance  with  the requirements for noise control of
  chutes in subchapter twelve of this chapter.
 
                 Table 15-9  Minimum Size of Charging Chutes
  ========================================================================
  Building Height         Location           If Square           If Round
  ------------------------------------------------------------------------
  7 stories or less      All 7 stories      22 1/2" x 22 1/2"    24" dia.
  8 to 30 stories        Top 7 stories      22 1/2" x 22 1/2"    24" dia.
                         8th to 30th
                           from the top     27"     x 27"        30" dia.
  31 stories and over    Top 7 stories      22 1/2" x 22 1/2"    24" dia.
                         8th to 30th
                           from the top     27"     x 27"        30" dia.
                         Remaining lower    32"     x 32"        36" dia.
  ========================================================================