Patent GB-463908-A (GB)
Title: Improvements in fermentation recorders
IPC: G01N7/22
Filed: 1936-05-07
Abstract: 463,908. Testing dough. NORMANDER, N. R. May 7, 1936, No. 12949. Convention date, May 8, 1935. [Class 58] An apparatus for recording the evolution of gas during the fermentation of dough, comprises a closable compartment 62 in which the dough is placed, a compartment 13 in which a floating bell 23 is arranged, a pipe 14 for leading evolved gas to the bell 23 and rods 26 carrying a pen 34 which co-operates with the rotary record-paper drum 38 to indicate the rise of the bell and consequently the evolution of gas. Two rods 26 are provided, each contacting with a roller 28, to prevent the bell 23 from rotating. The bell 23 has, at its base, a cylindrical ring 24 filled with air, and a weight 25 attached to the ring. This arrangement ensures a stable state of equilibrium and the weight is so arranged that the bell has a very slight tendency to sink prior to the introduction of gas. The compartments 62, 13 are surrounded by a temperature-maintaining liquid which is heated by an electric element 20 under the control of a thermostat 21. A signal may be operated when the dough has expanded to a predetermined extent, e.g., a metal plate may be placed on the top of the dough and rises with the dough until it connects two contacts in an electromagnet circuit, the armature of which is connected to a spring-loaded valve for venting the space 12. A switch, of the electric alarm type, causes the valve to reciprocate to open and close the vent. A manually operable vent is provided for the space 62, in order that the bell 23 may be returned to its original position. Holes 50 facilitate the passage of liquid to and from the bell. If desired, an additional floating bell chamber 52 may be provided for ascertaining the quantity of carbon di-oxide released from the dough. The bell 51 is of somewhat larger volume than the combined volumes of the bell 23 and of the space 12 less the volume of the dough. The bell 51 is connected to the space 62 by a pipe 54 controlled by a valve 55, and a pipe 56 controlled by a valve 57 runs from the bell to the outside of the casing 11. A further pipe 58 is connected to the atmosphere through a water seal 59 and, if desired, a receptacle 60 containing a water carrying substance, e.g. pumice-stone in order to moisten the air sucked in through the pipe. In operation, whilst the bell 23 is making the record, on the cylinder 38, of the amount of gas liberated from the dough plus the amount of air displaced by the rising dough, the valve 55 is closed, and the bell 51 which has a tendency to rise, is kept down by a vacuum therein. When the recording is ended, the valve 57 is closed, and the valve 55 is opened, the bell 51 in rising exhausting the bell 23, which sinks, and the space 62. The rise of the bell 51 is allowed to continue a little longer to draw in air through the pipe 58 to sweep the residual carbon dioxide out of the space 62 into the bell 51. The valve 55 is then closed and the valve 57 is opened, the gas in the bell being drawn, or forced by loading the bell, into a gas analyzing apparatus which determines the percentage of the carbon di-oxide content, or the volumetric amount thereof. The rising of the dough may be observed through a window 61.