FR2509138A1 - GAS AND BURNER FRYER FOR SUCH A FRYER - Google Patents

Abstract

THE INVENTION RELATES TO A FRYER AND A FRYER BURNER. IT RELATES TO A FRYER HAVING A TANK 20 IN WHICH IS PLACED A BURNER 30 WHICH TRANSMITS ITS COMBUSTION GAS TO A DUCT 60, THE COMBUSTION PRODUCTS THEN FLOWING IN CHANNELS FORMED ALONG THE END WALL 42 AND SIDE WALLS SO THAT THE HEATING OF THE FRYING OIL PLACED IN THE TANK IS OPTIMAL. THE BURNER 30 IS DESIGNED TO INITIATE AND DETECT THE ESTABLISHMENT OF COMBUSTION WITH A LOW GAS FLOW AND THEN, AFTER A LOW TIME, TO AUTOMATICALLY ADJUST THE NECESSARY GAS FLOW. APPLICATION TO FRYERS IN RESTAURANTS AND COLLECTIVITIES.

Description

The present invention relates to a gas fryer in restaurants and

  in other installations for frying fish, poultry, potatoes and other types of food, in a tank containing a frying oil The invention also relates to a gas burner in which the gas to to burn is injected into a

  swirl of air, of a useful type for a gas fryer.

  One type of gas fryer, as described for example in U.S. Patent Nos. 2,429,360, 2,452,472, 2,655,144 and 2,712,308, includes tubular heating devices which are mounted in the vessel. de-frying so that they are immersed in the frying oil The heat is efficiently transmitted from the heaters to the oil that is in

  However, these devices tend to become

  because of calcined residues and their cleaning is different

  For example, these heaters have several tubular elements that are grouped in the lower parts of the tank. Thus, such a fryer

  has a lower zone in which particles of food

  and breading tends to collect, and that is not heated so that the collected particles are not calcined, and the cleaning of this area is difficult given

  that it is covered by the tubular elements.

  U.S. Patent Nos. 2,251,111, 3,313,288, 3,970,072, 3,990,433 and 4,228,730 disclose gas fryers. U.S. Patent Nos. 2,185,594, 2 is incorporated herein by reference. 465,953, 3,554,182 and 4,014,316 disclose gas heated devices for applications

other than deep fryers.

  In addition, another type of gas fryer

  read gas heaters mounted below

  the tank but outside it so that the net

  cleaning of the tank is facilitated because the tank does not have an internal nodular structure that can become fouled by calcined residues and whose cleaning can be difficult. However, the particles of food and breading tend to collect on the parts. lower

  heated from the tank and to undergo a calcination.

  U.S. Patent No. 4,091,801

  describes such a fryer in which heat is trans-

  setting in frying oil that is in the tank by

  Via a vaporized fluid The United States Patent

  United States of America No. 3,964,378 describes another type of

positive gas heated.

  Another type of gas fryer, as described, for example, in U.S. Patent Nos. 3,809,062, 3,938,948 and 3,948,593 has gas burners placed near the side walls of a portion of a gas fryer. lower

  The heat is transmitted efficiently from the

  theirs to the frying oil that is in the trough to

  to walls that are oriented vertically close to the burners, so that horizontal surfaces that tend to allow the formation of boundary layers

  of hot cooking oil along the surfaces are minimal

  males. Gas burners of the aforementioned type are described, for example, in numerous documents such as US Pat. Nos. 2,539,165, 2,565,879, 2,787,318, US Pat.

3,630,651, 4,124,353 and 4,224,019.

  Since the cost of gaseous fuels has increased in recent years, gas fired fryers with high efficiency burners need to replace less profitable fryers used in restaurants.

and in other facilities.

  In addition, it is known that the gas flow transmitted to a main burner can be delayed by a suitable device, with a minimum delay following the establishment

  from combustion to a pilot burner, in an oven in the-

  which air is sucked into the burner by a partial vacuum created in the oven, the air and the flue gas being m langages at this burner However, this device does not appear to have been used so far in a burner in which air and gas to be combusted are mixed in a vortex of air, and wherein the air vortex is made from the air transmitted to the burner

  at low pressure which can be as low as 4 mbar.

  The invention relates to an improvement to fryers for food, of the type which comprises a tank having side walls and end walls and

  is intended to contain a cooking oil and to be

  see food to be fried in this oil, by implementing a burner mounted on the tank and which is intended to transmit a combustible gas and combustion air, and a conduit passing through the tank so that it is

  immersed in cooking oil and having a part of

  passing to a first end wall and in which combustion takes place, and an outlet portion reaching another end wall and in which

  the products of combustion are evacuated.

  An improvement according to which the frying tank has external channels for transmitting the combustion products of the outlet portion of the duct along the outer surfaces of the end wall reached by the outlet portion of the duct and along the outer surfaces of the side walls so that heat is transmitted from the combustion products

  which are in the channels through the end wall.

  reached by the exit part of the duct and

  to the side walls to the frying oil in the tank, the channels leading to outlets

  corresponding products of combustion.

  Preferably, the tank has isolating panels

  the side walls and the end wall closest to the outlet portion of the duct and which form external walls of the channels so as to

  that heat losses through the channels are limited.

  Preferably, the channels that are on the walls

  side sections have lower sections and upper sections

  so that they form sinuous paths of circula-

  combustion products between the duct and the outlets.

  In one embodiment, the sections

  are communicating with the outlet part of the duct

  through the channels at the wall of ex-

  tremity reached by the outlet portion of the conduit so that they receive the combustion products of the conduit, and

  the lower reaches communicate with the

  at the end wall reached by the inlet part of the duct so that the combustion products are evacuated, the upper sections being able to

  total section smaller than that of the lower sections.

  In another embodiment, the upper sections

  communicate with the outlet part of the duct by means of

  intermediate channels, at the end wall reached by the outlet portion of the conduit to receive the combustion products from the conduit, and the lower sections communicate with the upper sections near the end wall reached by the entrance part of the duct, the lower sections having

  a lower overall section than the higher ones

  Preferably, the inlet portion of the conduit has a circular cross-section, the outlet portion of the conduit has a vertically elongate section, and the conduit has a portion

  transition between the input portion and the output portion.

  The invention also relates to a burner for a gas fired fryer or other gas heated apparatus, comprising an enclosure having a cylindrical wall having a central axis, a flat wall closing a first end of the cylindrical wall and an opening of an output axially opposed to the flat wall, a duct which is mounted on the enclosure so that it enters the enclosure through a slot formed in the cylindrical wall and that it is arranged tangentially in the enclosure, this duct being intended to be connected to a source of air at a pressure above atmospheric pressure so that it forms a vortex of air around the central axis, inside the enclosure, a manifold which has side outlets and

  who is mounted on the speaker so that he enters

  ci by an opening formed in the flat wall and that it is arranged axially in the chamber, transversely to the duct, the collector being intended to be connected to a source of combustible gas at a pressure greater than atmospheric pressure so that it injects the biggest

  part of the gas from the gas source in a tower

  air billon formed in the enclosure, an injector mounted on the enclosure so that it enters it through an opening formed in the flat wall and which is intended to be connected to the gas source so that it injects a small portion of the gas from this source into the enclosure, a valve connected to the manifold to regulate the flow of most of the gas supplied to the manifold, a

  device for triggering combustion in the

  to detect the moment when the combustion is established in the chamber and to cause the opening of the valve when it has detected that the combustion has been established in the enclosure, and a device for delaying the opening

  of the valve for a minimum delay of approximately 1 to 2 sec-

  after the detection of the establishment of the

  in the chamber, so that air can be transmitted into the chamber at a pressure in the duct which is as low as about 4 mbar, without flashback, without oscillation of the flame, and without defect ignition

after opening the valve.

  Preferably, the collector and the injector are connected to the gas source so that the small portion of gas forms about one-eighth to one-quarter of the total amount of heat energy of most and the smallest part of the gas. gas both The gas source preferably transmits gas at a rate such that the total amount of heat energy of the small portion and the large portion of gas is such that the power of the burner is about 12 k W, the air source transmitting air

  with a flow rate corresponding to 12.7 m 3 / h approximately.

  Preferably, a curved deflector is mounted in the enclosure so that it deflects the vortex helically towards the central axis. The injector is preferably arranged so that the small part of gas is injected into the chamber.

  the vortex where it is deflected by the

  flector The device intended to ignite the gas in

  the enclosure is preferably placed in such a way that

  the combustion near the central axis.

  Other features and advantages of the

  will appear better from the description which will follow,

  with reference to the accompanying drawings in which Figure 1 is an elevation with parts

  removed from an embodiment of fryer according to the invention.

  vention; Figure 2 is a plan view of the fryer of Figure 1; Figure 3 is a section along the line 3-3 of Figure 1; Figure 4 is an end view with torn portions of the fryer of Figure 1, according to the arrows 3; Figure 5 is a partial elevation, similar to Figure 1, of a variant of fryer construction according to the invention; Figure 6 is a section on the line 6-6 of Figure 5; Fig. 7 is an enlarged elevation of a burner used in the fryer of Fig. 1, as it appears after removal from the bowl and other fryer members, end-to-end; Figure 8 is a section along the line 8-8 of Figure 7; Figures 9 and 10 are diagrams of valve mounting variants of the fryer of Figure 1; and FIG. 11 is an electrical diagram used

  for controlling the arrangement of Figure 9.

  In FIGS. 5 and 6, the numerical references followed by the 'are elements similar to those

  the same numerical reference, without the sign ', on the

gures 1 to 4.

  The fryer shown in FIGS.

  4 is of a type used in restaurants or in other

  very facilities for frying fish, poultry, potatoes, and other types of food, and includes a vessel 20 having an envelope 22 and other elements described hereinafter , the vessel being intended to contain frying oil (not shown) placed in the casing 22 and to receive food (not shown) to be fried in the oil. In addition, the fryer has a burner 30 associated with a blower 32 and which is mounted on the tank 20 Food can be

  introduced into a basket of conventional type (not shown).

  The tank 20 and the burner 30 can be mounted in a

  classical box, which is not represented either.

  The envelope 22 which can be formed of a steel

  stainless steel suitable for welded joints and having internal corners

  A plurality of pins 50 which facilitate cleaning, have opposite end walls 40, 42, opposite side walls 44, 46 and a bottom 48 have a plurality of pins 50 which carry the burner 30 as described hereinafter.

  memory are welded to the bottom 40 according to a circling arrangement

  formed of a circular opening 52 of the end wall 40 thereof has a rectangular opening 54 to

  a location opposite.

  An elongated conduit 60 formed of suitable stainless steel is disposed in the vessel 20 between the walls 40,

  42 end so that it is immersed in the oil of fri-

  when the vessel 20 contains a sufficient amount of oil for a normal frying operation.

  has an entrance part 62 in which a

  bustion, and a part of 64 output in which the

  The inlet portion 62 which reaches the end wall 40 is cylindrical so that its section is circular, so that the inlet portion 62

  has a volume that is suitable for the implementation of combustion.

  The outlet portion 64 that reaches the end wall 42

  has a rectangular shape and is oriented so that its

  vertically elongated, so that the trans-

  heat generated from the combustion products that are in the outlet 64 portion to the oil-frying placed

  in the tank 20 is favored because the oil has a tendency to circulate

  flow along the vertical surfaces of the convection outlet portion 64 A transition portion 66 connects

  the input portion 62 to the output portion 64

  The inlet end 72 of the portion 62 is welded at its edges around the opening 52. An outlet end 74 of the portion 64 flares laterally (as shown) and is

  welded by its edges around the opening 54.

  The side wall 44 is pressed so that it has a shape symmetrical to that of the side wall 46 and has a channel 92 which protrudes inwards and which has a lower section 94 and an upper section 96. A rib 98 formed in the side wall 44 separates the two sections 94 and 96, but the upper section 96 communicates with the lower section 94 near the wall 40

  A panel 100 of thermally insulating material

  is pressed against the side wall 44 by a device

  suitable for tightening so that it forms an outer wall

  Canal 92 and thus minimize losses to each

  their channel, which does not have a metal wall

external link.

  The side wall 46 is pressed so that it has a shape symmetrical to that of the side wall 44

  and has a channel 11-2 analogous to channel 92 and which

  thus passes inward, with a lower portion 114 and an upper portion 116 A rib 118 formed in the side wall 46 separates the lower portion 114 of the upper portion 116, but the latter communicates with the lower portion 114 near the wall 40 end of a thermal insulation panel 120 is clamped against the side wall 46 by a suitable clamping device not shown so that it forms the outer wall of the channel 112

2 '509138

  minimizing heat loss from this channel

  which therefore has no external metal wall.

  A thermal insulation panel 140 is clamped against the end wall 42 by a suitable device, not shown, and is constructed in such a way that it forms

  other channels 142 that transmit the products of com-

  venting the outlet portion 64 of the conduit 60 to both the upper section 96 of the channel 92 and the upper section 116 of the channel 112 The panel 140 closes the adjacent end of the lower section 94 of the channel 92, except at a output formed by a conduit 146 which passes through a suitable opening of the panel 140 and thus communicates with the section

  less 94 so that it can evacuate the products of com-

  The panel 140 closes the adjacent end of the section

  lower portion 114 of the channel 112, except for an outlet provided with a duct 156 which passes through a suitable opening of the panel 140 and communicates with the lower section 114 if

  although it can evacuate the products of combustion

  146 and 156 are torn off in FIGS. 1, 2 and 4.

  The panels 100, 120 and 140 which are considered as elements of the tank 20, may be formed of a conventional rigid fibroceramic material, available from

  from various suppliers The clamping devices of

  100, 120 and 140 may be in the form of an enclosure

  no represents constituted by a metal sheet.

  In the tank 20 of FIGS. 1 to 4, the combustion products are the hottest in the duct 60;

  have an intermediate temperature in the upper sections

  96 and 116, and they are the coldest in the

  are less than 94, 114, so that the transfer of

  their burning products to the frying oil placed

in the tank 20 can be maximum.

  As shown in Figures 1, 3 and 4, the

  lower sections 94 and 114 have an overall cross-section

  than the upper sections 96, 116 so that the products of combustion are accelerated when they cool in the channels 92, 112 Similarly, the upper sections 96, 116 have an overall section

  less than that of the exit portion 64 of the duct 60.

  As indicated in FIGS. 5 and 6, a tank 'is similar to the tank 20, except for the points indicated now. An elongated conduit 60' which is analogous to

  conduit 60 is also associated with the vessel 20 '.

  tremity 74 'output of a portion 64' output of the con-

  duct 60 'flares laterally as shown and is welded at its edges around an opening 54' formed in

  an end wall 42 'of the tank 20'.

  A side wall 44 'of the tank 20' is embossed

  to be symmetrical with a side wall 46 'and has a channel 92' which thus protrudes inwards

  and has a lower section-94 'and an upper section 96'.

  A rib 98 'formed in the side wall 44' separates the lower section 94 'from the upper section 96', except where the two sections communicate in the vicinity of an end wall (not shown) opposite the wall 42 'end A panel 100' which is similar to the panel 100 is pressed against the side wall 44 'by a suitable device not shown so that it forms an outer wall of the channel 92' and thus minimizes heat loss of this canal which therefore has no wall

external metal.

  The side wall 46 'of the tank 20' is stamped so that it is symmetrical with the side wall 44 'and has a channel 112' similar to the channel 92 '. A lower section 114' of the channel 112 'is shown in FIG. A panel 120 'similar to the panel 120 is clamped against the side wall 46' by a suitable device so that it forms an outer wall of the channel 112 'and thus minimizes channel heat loss which therefore has no problem.

external metal wall.

  A panel 140 'of thermal insulation, similar to the panel 140, is clamped against the end wall 42'

  by a suitable device not shown and it is

  in order to delimit other channels 142 'which conduct the combustion products from the outlet portion 64' of the conduit 60 'both to the lower section 94' of the channel 92 'and to the lower section 114' The panel 140 'closes the adjacent end of the upper section 96' of the channel 92 ', except for an outlet formed by a duct 146' which passes through a suitable opening of the panel 140 'so that it communicate with the

  upper section 96 'and thus evacuate the products of com-

  Bustion The panel 140 'closes the adjacent end of the not shown upper section of the channel 112', apart from

  an outlet formed by a conduit 156 'which passes through an

  suitable opening formed in the panel 140 'so that the conduit communicates with the upper section of the channel 112' and thus evacuate the combustion products The conduits

  146 ', 156' are torn off in FIG.

  In the tank 20 'of FIGS. 5 and 6, the

  combustion fumes are the hottest in the duct

  'at an intermediate temperature in the lower reaches

  94 'and 114' and the coldest in the upper sections of the channels 92 ', 112', so that the risk of calcination of the oil at its upper face can be minimized, even when the cooking oil is in insufficient quantity to expose the internal faces of the side walls 44 ', 46' close to the channels 92 ',

112 '.

  As shown in Figures 5 and 6, the section

  upper section 96 'is smaller than the lower section

  94 'and it should be noted that the overall section of the section above

  The lower channel 114 'is smaller than that of the lower section 114' so that the combustion products are accelerated when they cool in the channels 92 ', 112'. Similarly, the lower sections of the channels 92 ', 112' , although they are not represented, may have an overall section smaller than that of the

  outer portion 64 'of the conduit 60'.

  The burner 30 comprises an enclosure 210 which has a cylindrical wall 212 having a central axis, a wall

  plate 216 closing a first end of the cylindrical wall

  drique 212, and a circular output 220 opening axial-

  The annular flange 222 which is integral with the cylindrical wall 212 surrounds the outlet 220 and has a circular arrangement of suitable holes 224 in which the pins 50 pass, so that the burner 30 mounted on the end wall 40 of the tank 20 The pins 50 which are threaded carry nuts 226 which hold the burner 30 on the tank 20 In FIG. 1, one of the axes 50 is shown and one nuts

  When the burner 30 is mounted on the tank 20, the

  220 communicates with the opening 52 formed in the end wall, and the inlet portion 62 of the conduit 6-0 and the enclosure 210 form an elongate cylindrical chamber in

which combustion takes place.

  A duct 230 which is advantageously mounted on the enclosure 210, is connected to the fan 32 which constitutes a source of air at a pressure greater than atmospheric pressure. The duct 230 which narrows to a groove 242 of rectangular shape in cut, enters the enclosure 210 by a large rectangular slot so that it is arranged tangentially to the enclosure 210 when the

  blower 32 works, a whirlwind of air is so -

  formed around the central axis inside the enclosure 210. A collector 250 which is tubular and perforated

  is mounted on the speaker 210 so that it enters

  ci by an opening formed in the wall 216 and be dis-

  placed axially in the direction transverse to the groove 242 of the conduit 230, in the enclosure 210 The collector 250 is

  connected to a source of combustible gas at a higher pressure than

  than atmospheric pressure, by means of

  252, a conduit 254 and other elements described below so that the majority of the source gas is injected into the air vortex formed in the enclosure 210 A small portion of the gas source is injected separately in a manner described hereinafter The gas source is schematically identified

  by the reference G in Figures 9 and 10.

  An injector 260 which is tubular, is mounted on the enclosure 210 so that it enters it through an opening formed in the wall 216 As shown in Figure 1, the injector 260 has a threaded end which is screwed The injector 260 is connected to the gas source via a connector 262, a conduit 264 and other elements described hereinafter so that the small portion of the gas of the source is injected into the enclosure 210 A curved deflector 270

  is mounted in the enclosure 210 so that it deflects the tourbil-

  lon of air formed in the enclosure in a helix towards the central axis.

  The injector 260 is arranged so that it injects the small portion of gas into the vortex at the o

  it is deflected by the deflector 270.

  In a first arrangement represented on the

  9, a solenoid valve 300 has its output connected to the collar.

  reader 250 through the conduit 254 and the connector 252 so that it regulates the flow of most of the gas transmitted to the collector 250 A solenoid valve 310 has its output connected to the inlet of the solenoid valve 300 The solenoid valve 310 has also its outlet connected to the injector 260 by a needle valve 320, the conduit 264 and the fitting 262 so that it

  regulates the flow of the small part of gas transmitted to the

  The relative proportions of the large part and the small portion of gas are manually adjusted by means of the needle valve 320. The solenoid valve 310 has its inlet connected to the gas source G via a pressure regulator 330. a manual valve 340 A fixed orifice

  not shown can replace the needle valve 320.

  The solenoid valve 300, the solenoid valve 310, the needle valve 320, the pressure regulator 330 and the manual valve 340 are available in combination as a unit called "Series G 53 Redundant Combi-

  Gas Valve Nation with Manual Shutoff "A" Valve "and available from Johnson Controls, Inc., Control Products Division, 2221 Camden Court, Oak Brook, IL 60521.

  Bulletin No. 4434 of Johnson Controls, Inc., describes this

  seems that is used for example for the elec-

different types of ovens.

  In another arrangement represented on the

  10, a solenoid valve 400 has its output connected to the

  250 through the conduit 254 and the connector 252, so that it regulates the flow of most of the gas transmitted to the collector 250 The solenoid valve 400 has its input connected by a device 410 with delayed opening, at the output of a pressure regulator 420 whose input is connected to the output of a solenoid valve 430 This has its output which is also connected to the injector 260 by a needle valve 440, the conduit 264 and the fitting 262, so as to that it regulates the

  flow rate of the small portion of gas transmitted to the injector 260.

  The relative proportions of the gas are set manually by the needle valve 440 The solenoid valve 430 is connected

  by a manual valve 450 to the gas source G

  410 with delayed opening which limits the flow of gas from the regulator 420 to the solenoid valve 400,

  delay the opening of the latter for a long time.

  glable after opening the solenoid valve 400 It is also

  adjusted so that it introduces a minimum delay of

  1 to 3 seconds within the scope of the invention A fixed orifice (not shown) can replace the needle valve 440.

  A previously conditioned set, equivalent

  to the solenoid valve 400, the device 410 with the

  delayed, the pressure regulator 420, the solenoid valve 430, the needle valve 440 and the manual valve 450

  is available as Unitrol 7000 BDER Combi

  Automatic Gas Valve Nation, from Robertshaw Controls Co., Grayson Controls Division, 100 West Victoria Street,

Long Beach, California 90805.

  The burner 30 comprises a device 500 of

  intermittent pilot-operated electric lighting of a conventional type used for the initiation of combustion, for the detection of the establishment of combustion and for the opening of a valve when the establishment of combustion has been detected, and this device is available under the designation "Fenwal 05-20 Ignition System" from Walter Kidde & Co, Inc., Fenwal Electronics Division, 63 Fountain Street, Framingham, Mass. 01701 Device 500 includes an ignition electrode 510 and detection which enters the enclosure 210 through an opening formed in the wall 216 and which is parallel to the central axis of the wall 212 but remote from this axis, and a rod 520 of mass which enters the enclosure 210 by a opening

  formed in the wall 212 and which is arranged perpendicularly

  electrode 510 so that a small space remains between its farthest end and the electrode 510.

  device 500 is connected in such a way that it triggers the

  bustion in the enclosure 210, that it detects the establishment of

  combustion in the enclosure 210, and that it causes the

  solenoid valve 300 or 400 of the arrangement of FIG. 7 or 8 respectively when the establishment of the combustion in the enclosure 210 is detected. If the arrangement of FIG. 7 is used, the device 500 is connected to the 11, in which a delay relay 540 is mounted so as to delay the opening of

  the solenoid valve 300 for a minimum time of about 1 to 3 seconds.

* after the establishment of combustion in the

  220 is detected by the device 500. When using the arrangement of FIG. 8, the device

  410 delayed opening delays the opening of the electro-

  400 valve of an equivalent period.

  In the electrical circuit of FIG. 11, the device 500 is connected in such a way that it is powered by a source 550 of alternating electrical energy at 24 V and or 50 Hz. The device 500 has an input 552 connected to

  the power supply 550 by a thermostat 560, an output 562 re-

  linked to the control winding 564 of the solenoid valve 310, and an output 566 connected to the control winding 568 of the relay 540 delay The contacts 570 of this relay 540 are mounted between the output 566 and the winding 572 of Thus, if the manual valve 340 is open and the blower 32 is operating, the device 500 opens the solenoid valve 310 and forms a spark in the small space separating the electrode 510 from the rod 520 if

  although the combustion is triggered in the enclosure 210.

  When the device 500 detects the establishment of the

  bustion, it controls the relay 540 delay which closes its contacts 570 and thus opens the solenoid valve 300 after the minimum delay of about 1 to 3 seconds The thermostat 560

  which can be of any suitable type, is mounted

  Conveniently in the tank to detect the temperature in it, and thus provides protection against overheating. When using the arrangement of FIG. 10, a similar circuit is used, this circuit does not

  not including the 540 delay relay; exit 562 from the dis-

  positive 500 is connected to the control winding of the elec-

  trovanne 430 and the output 566 of the device 500 is connected to the control winding of the solenoid valve 400 Thus, if the manual valve 450 is open and the fan 32 is running, the device 500 opens the solenoid valve 430

  and forms a spark in the small space separating the elec-

  510 trode out of the 520 stem, thus triggering the burning -

  in the enclosure 210 when the device 500 detects the

  ignition of the combustion, it excites the solenoid valve 400 which opens after the minimum delay of about 1 to 3 seconds,

  this being due to the delayed opening device 410.

  The burner 30 can be made with an internal diameter of 51 mm for the enclosure 210, an internal length of 44.5 mm and an internal width of 10.2 mm in the groove 240, a space of 3.18 mm for the the formation of the spark, twelve perforations of 1.58 mm diameter each, formed in the collector 250, an outer diameter of the collector 250 equal to 6.35 mm, a spacing of 14.5 mm between the central axis of the enclosure 210 and the central axis of the injector

  260, and with a deflector 270 in the form of a cylindrical wall

  with a diameter of 44.5 mm, all these dimensions

being approximate.

  When the burner 30 has the dimensions which come

  indicated and when the fryer 10 has a function

  effective, the blower 32 transmits air 210 to the enclosure 210 at a pressure which, in the groove 242, is reduced from 9 to 4 mbar, with a flow rate of 12.7 m 3 / h, and the

  source of gas and the valves regulating the flow of

  from the source to the collector and the injector are

  arranged in such a way that the total amount of energy

  lorific (most and the smallest portion of gas) is about 10 k W, the small portion of gas constituting one-eighth to one-quarter of that

  It should be noted that natural gas, syngas

  thetic and other fuels in gaseous form have

  different heating values.

  Thus, the burner 30 can operate with good efficiency in the fryer 10 without flashback, without flame oscillation and without ignition fault after opening the valve regulating the flow of the largest

part of the gas.

Claims (15)

  Food fryer, of the type which comprises (a) a vessel (20) having side walls (44, 46) and end walls (40, 42), the vessel being adapted to contain a frying oil and receiving oil-fried foods, (b) a burner (30) mounted on the vessel (20) and for transmitting a fuel gas, and (c) a conduit (60) disposed in the vessel (20) for it is immersed in frying oil and having an inlet portion reaching a first end wall and in which combustion occurs, and a portion of   exit reaching the other end wall and in the-   wherein the combustion products are discharged, characterized in that the vessel (20) has external channels (92, 112) for conducting the combustion products of the outlet portion of the conduit (60) along the outer faces of the end wall (42) reached by the outlet portion of the conduit and along the outer side wall faces (44,46) so that the heat of the combustion products in the channels is transmitted to   the frying oil in the vat (20) by the   intermediate of the end wall reached by the outlet portion of the duct and the side walls, the channels (92, 112) formed in the side walls leading to   outputs of combustion products.   2 fryer according to claim 1, characterized in that the tank has thermal insulation panels (100,   , -140) covering the side walls (44, 46) and the -   end wall (42) reached by the outlet portion of the duct, these panels forming the outer walls of the channels   so that they limit the heat loss of the channels.   3 fryer according to one of claims 1 and 2,   characterized in that the channels (92, 112) of the side walls   Rails have lower sections (94, 114) and upper sections (96, 116) so that they form sinuous paths for circulation of the products of combustion between the duct. and the outputs.   4 Fryer according to claim 3, characterized in that the lower sections (94 ', 114') communicate with the outlet portion of the duct (60 ') through the channels formed in the end wall reached by the outlet portion of the conducted to receive the combustion products of the conduit, the lower sections (94 ', 114') communicating with the upper sections (96 ', 116') near the end wall (40 ') reached by the part input   duct so that the products of combustion are evacuated.   Deep fat fryer according to Claim 3, characterized in that the upper sections (96, 116 ') communicating   with the outlet part of the duct (60) by the canals   in the end wall (42) reached by the outlet portion of the conduit to receive the combustion products of the conduit, and the lower portions (94, 114).   communicate with the upper sections (96, 116) close to   mity of the end wall (40) reached by the inlet portion of the conduit so that the combustion products be evacuated.   Deep fryer according to one of claims 1 and 2,   characterized in that the inlet portion of the conduit (60) has a circular cross-section, the exit portion of the conduit (60) has a vertically elongate section, and the conduit has a transition portion between the inlet portion and the exit part.   Fryer according to Claim 6, characterized in that the channels (92, 112) of the side walls (44, 46)   have lower sections (94, 114) and upper sections   (96, 116) to form sinuous paths for   combustion products, between the duct and the outlets.   8 fryer according to claim 7, characterized in that the lower sections (94 ', 114') communicate with the outlet portion of the duct (60 ') by the channels of the end wall (42') reached by the party of   exit the conduit so that they receive the products of   from the duct, and the lower sections (94 ', 114') communicate with the upper sections (96 ', 116') near the end wall (40 ') attained by the   part of the duct so that the products of com- bustion be evacuated.   9 fryer according to claim 8, characterized   in that the upper sections (96 ', 116') have a section   lower overall level than lower sections (94 ', 114').   Deep fat fryer according to Claim 7, characterized in that the upper sections (96, 116) communicate with the outlet part of the duct (60) via the channels of the end wall (42) reached by the outlet part of the duct. (60) to receive the combustion products of the conduit, and the lower sections (94, 114) communicate with the upper sections (96, 116) near the end wall (40) reached by the part   duct inlet (60) so that the combustion products be evacuated.   11 fryer according to claim 10, characterized in that the lower sections (94, 114) have a section   overall lower than that of the upper sections (96, 116).   12 Deep fryer burner according to any one of   preceding claims characterized in that it comprises:   (a) an enclosure (210) having a cylindrical wall   with a central axis, a flat wall closing a first end of the cylindrical wall, and a large outlet opening axially opposite to the flat wall, (b) a duct (230) mounted on the enclosure so that it enters the latter by a slot formed in the cylindrical wall and that it is arranged tangentially in the context, this duct being intended to be connected   to a source of air at a pressure greater than the pressure   mospheric so that it forms a vortex of air around the central axis, inside the enclosure,   (c) a collector (250) having side outlets   mounted on the enclosure so that it enters the enclosure through an opening formed in the flat wall, inside the enclosure, the manifold being intended to be connected to a source of combustible gas at a pressure greater than the atmospheric pressure so that the majority of the gas from the source is injected into a vortex of air formed in the enclosure, (d) an injector (260) mounted on the enclosure to enter the by an opening formed in the flat wall and intended to be connected to the gas source so that it injects a small portion of the gas from the source into the enclosure, (e) a valve connected to the collector so that it regulates the flow rate of most of the gas supplied to the collector, (f) a device (500) for triggering combustion in the enclosure, for detecting the establishment of combustion in the enclosure, and for causing the opening   of the valve after detecting the establishment of the   venting within the enclosure, and (g) a device for delaying the opening of the valve for a minimum delay time of approximately   1 to 3 seconds after detecting the establishment of the   bustion in the enclosure, so that air can be transmitted in the enclosure to   a pressure in the duct as low as 4 mbars   ron, without flashback, without flame oscillation   and without ignition fault after opening the valve.   13 burner according to claim 12, characterized in that the collector (250) and the injector (260) are connected to the gas source so that the small portion of gas brings from one-eighth to one-quarter of the total amount of heat energy of the biggest part and the small part gas.   Burner according to Claim 13, characterized in that the gas source (G) transmits gas at a rate such that the total heat energy of the major part and the small gas portion is approximately 12 k W, the air source transmitting the air with a flow of about 12 m 3 / h.   Burner according to any one of the claims   12, 13 and 14, characterized in that it comprises a   curved flector (270) mounted in the enclosure (210) to deflect the vortex helically towards the central axis. Burner according to Claim 15, characterized in that the injector (260) is arranged in such a way that   injects the small part of gas into the whirlpool   right o it is deflected by the deflector (270).   Burner according to Claim 16, characterized   in that the gas ignition device (520) within the   The loudspeaker of the enclosure is arranged so that it   combustion near the central axis.