CN1493230A

CN1493230A - Superhigh temperature disinfecting method of solid food and its apparatus

Info

Publication number: CN1493230A
Application number: CNA021377898A
Authority: CN
Inventors: 力邓; 邓力
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-10-28
Filing date: 2002-10-28
Publication date: 2004-05-05

Abstract

A method and equipment for ultrahigh-temp sterilizing of solid food in short time features that a direct forced heat exchange is conducted between the gas-state or liquid-state heat transfer medium used as the component of food and the solid food to quickly raise the temp of solid food to 130-150 deg.c within 2-8 S in pressure condition without water evaporation, and then vacuum evaporation and the direct forced heat exchange with low-temp heat transfer medium to quickly cool the food.

Description

A kind of superhigh temperature disinfecting method of solid food and device thereof

Technical field the present invention relates to the pasteurization method of solid food and realizes the device of this method, particularly relates to the superhigh temperature disinfecting method of solid food and realizes the device of this method.

The main pasteurization mode of the present solid food of background technology is still at the A Shi method for disinfection and the modification method thereof that adopt 19th-century to occur.In the sterilization still, be still topmost sterilization means to be higher than 100 ℃ the temperature pasteurization and the sterilizing kettle in sterilization method of back-pressure cooling.These method for disinfection have identical feature: under certain pressure across container by the food in steam or hot water or the flame heat packing, make the center of food be warmed up to sterilization temperature.This process must make heat transfer efficiency be restricted.If the food in the packing is that liquid and solid mixture are arranged, during sterilization by behind the liquid in the packaging material heating packing, transfer heat to the solid food surface again, make the center of food be warmed up to the temperature that sterilization needs by the heat conduction then, must cause liquid to be subjected to superheated in this case.If be solid fully, by the gas heat-transfer in packaging material and the packing to the solid food surface, and then by heat conduction make the food center be warmed up to sterilization need temperature, in this case, heat transfer efficiency is lower, and the part that the solid food surface contacts with packaging material is subjected to superheated.Pack the big more heat temperature raising of big more solid food volume and the time that cools just long more.For the low acidity food of different material, Different Package amount and Different Package form, the pasteurization time more than 100 ℃ is between 10min～2hr, and is most between 20min～1hr.Such heating intensity, heavy damage flavours in food products, reduced food quality, the food that thermal sensitivity is strong then may not adopt this method for disinfection, thereby has limited machinable food kind greatly.Though improved sterilizing kettle in sterilization technology such as swinging method for disinfection, temperature-gradient method method for disinfection can shorten heat time heating time effectively, reduce heating intensity, the too high defective of heating intensity in the time of can not the radical change sterilization.The reason of its essence is exactly that to carry out the heat transfer efficiency that indirect causes across container low, cause heating up and cooling rate slow, heat time heating time is long, part food is subjected to superheated.

People improve product quality and have done a lot of effort for reducing the sterilization heating intensity of solid tinned food.The passable progress of this respect from the 3rd piece of chapter 11 in " modern food engineering new and high technology " (Beijing such as Gao Fucheng: China Light Industry Press, 1997).In recent years, ohm sterilization ripe day by day makes the ultra high temperature sterilization of the food that liquid mixes with solid particle become possibility.The food of the low-frequency ac electrical heating preheating by 50～60Hz cooperates aseptic cooling and sterile filling can obtain the packaged food of higher quality.Sterilization temperature can reach 140 ℃, and sterilizing time is at 0.2～15min, because the uniformity of electric field heating, has avoided overheated as the liquid part of heat transfer medium, has improved the quality of food greatly.But ohm sterilization technology only is only applicable to granule content in the liquid less than 40% food, limited its range of application, and owing to adopt the scraper plate cooling means, cooling rate is restricted, and higher heating intensity is still arranged.At present also not at the superhigh temperature disinfecting method that is the food of solid fully.

Desirable pasteurization effect should be able to guarantee food quality to greatest extent when reaching commercial sterilising conditions, in the various sterilization technologies superhigh temperature in short-term (instantaneous) sterilization technology apparent in view technical advantage is arranged.The general definition of superhigh temperature (UHT) sterilization is to heat 2～8s down at 135～150 ℃, and heating back product reaches the sterilization process of commercial sterilization requirement.101～135 ℃ of high temperature sterilization temperature that adopt in the relative low acidity food conventional sterilization of this sterilization conditions, temperature is high 10～40 ℃, therefore is called superhigh temperature.And for some acidity and peracidity food, adopt the sterilization temperature less than 100 ℃ in the conventional sterilization method, and carry out in ultra high temperature sterilization equipment in the sterilization, heating-up temperature may be at 80～135 ℃, temperature is also high 10～40 ℃, and this sterilization temperature is also referred to as ultra high temperature sterilization usually.Superhigh temperature is a relative notion on therefore certain meaning.(beautiful Xu keeps deep Beijing: China and light industry publishing house in " dairy products ultra high temperature sterilization and aseptic packaging ", 1986) and " modern food engineering new and high technology " the 3rd piece of documents such as (high good fortune become Beijing: China Light Industry Press, 1997) in can recognize superhigh temperature disinfecting method, device and the principle of various liquid foods.Since the fifties in last century the Britain scientist to the pioneering research of stork process, the The Technology of The UHT of low acidic liquid food is all to have obtained great success in theory research or in the technology application over nearly 60 years.Hang down the long-time preservation of acidic liquid food owing to can obtain making under the maximum condition of preserving, brought revolutionary variation to the production and processing of dairy products and other protein beverage goods at nutrition and flavor characteristics.The theoretical foundation of ultra high temperature sterilization is very firm at present.A large amount of sterilization thermodynamics and Food Chemistry thermodynamics experiments show, microorganism is higher than the sensitiveness of most food compositions to high temperature to the sensitiveness of high temperature, under the high temperature (130～150 ℃) can be in very short time kill microorganisms effectively, and keep the due quality of food preferably.This theory is applicable to solid food fully, but because solid food is not easy to realize high efficient heat exchanging, the difficulty of technical existence is not applied the ultra high temperature sterilization of solid food as yet.The ultra high temperature sterilization equipment of liquid food, very ripe as direct-heating type (steam-sprayed, food is pouring-in) and the The Technology of The UHT and the equipment of indirect heating type various ways such as (tubular type, chip, scraper-types).Can consult and a large amount of relevant patented technology that retrieves APV international corporation, α-LAVAL company.Various and vapour mixture that these technical methods adopt or high efficient heat exchanging heating means all are fully at liquid, can not be applied to solid food.It is worthy of note that all The Technology of The UHT are except cooperating efficiently aseptic fast cooling, aseptic packaging is necessary supporting technology.Now aseptic packaging technology has reached higher level, produces in a large number that filtrated air (or nitrogen) forms sterilized space and relevant technologies that the sterilization and the sterile equipment of packaging material are cleaned becomes better and approaching perfection day by day.

The industrial food of Chinese meal processing at present more and more widely, from the tinplate can to the Soft packed can head food, the kind kind is a lot, but the low acid tinned food in long frame longevity all is to adopt the long-time sterilization of high temperature, the dull local flavor that too high heating intensity produces has had a strong impact on the edibility local flavor of food, lacks the due feeling of freshness of Chinese meal.Being processed with stir-fry, frying in shallow oil, exploding, stewing of Chinese meal, burning, braised, halogen, form such as mix, now the packing Chinese meal food kind on the market mainly is the bigger kind of heating intensity in the traditional Chinese dish, for example adopt burn, boil, stew, the food of processes such as halogen.Account for diet more the cooking of vast scale then do not have substantially.The conventional sterilization technology is when handling meat at present, (shearing strength was low excessively when meat fiber was loose, edible can to produce disorganization, lose the fresh and tender mouthfeel of meat), the defective of local flavor oppressiveness (long-time heating form tangible boiling flavor), in today that the consumer improves constantly the requirement of dietetic flavor quality, such food squeeze attraction.The conventional sterilization technology more can't be applied to the vegetable raw-material of thermal sensitivity common in the cooking.

Purpose of the present invention is exactly to set up the food superhigh temperature method for disinfection in short-term that a kind of object is solid fully, by reducing heating intensity significantly, make by the flavours in food products of sterilization, tissue and nutritional quality and obtain effectively so that the raising of essence makes the solid food of some thermal sensitivitys such as Chinese meal to become long frame longevity packaged food by industrial processes.

Summary of the invention ultrahigh temperature sterilization of solid food method of the present invention may further comprise the steps:

(1) food for the treatment of sterilization enters an enclosure space;

(2) above-mentioned enclosure space is applied the pressure that maximum moisture vapor is pressed when being higher than sterilization;

(3) heated gas or the liquid heat-transfer medium that can be used as food composition occupy above-mentioned enclosure space and fully with the even velocity of flow solid food of flowing through, with forced convertion mode heated food surface, by the heat conduction, make the solid food central temperature reach sterilization conditions again;

(4) stop forced convertion, enclosure space is progressively reduced pressure until negative pressure, food rapid evaporation radiating and cooling is got rid of steam and residual liquid heat transfer medium simultaneously; Perhaps enclosure space is progressively reduced pressure until negative pressure, after the food rapid evaporation radiating and cooling, again by the cryogenic heat transfer medium with the even velocity of flow solid food of flowing through, with forced convertion mode cooling food, food is further lowered the temperature, and get rid of the residual liquid heat transfer medium; Perhaps by the decompression evaporation radiating and cooling, and directly by the cryogenic heat transfer medium with the even velocity of flow solid food of flowing through, with forced convertion mode cooling food, make food cooling cooling, and get rid of the residual liquid heat transfer medium;

(5) food of finishing sterilization breaks away from enclosure space, enters the aseptic packaging operation.

A kind of device first that is used to realize method of the present invention, this device comprises:

A plurality of sterilization containers 21 are the container-like object of open-top, the bottom or all be solid food can not by and heat transfer medium can freely through network structure, be used in sterilization process, loading solid food through preprocessing;

The container-like member that an end face that is referred to as sterilization 19 opens wide;

The container-like member that end face that is referred to as sterilization seat 25 opens wide and can be sealed and matched with the sterilization head, sterilization head and sterilization seat can relative motions, sterilization container can enter between the two in the time of separately, when closing up two unlimited end faces by sealing ring 18 airtight formation sealings the sterilization space and comprise sterilization container.

One cover makes relative motion between sterilization head and the sterilization seat, and makes both form the mechanical device of enclosure space;

A network structure 20, being fixed on sterilization head inside, to cover sterilization container uncovered, heat transfer medium can freely pass through and food is intransitable, effect be when preventing the forced heat-exchanging pasteurization solid food along with heat transfer medium flows;

One cover pushes sterilization seat correct position with sterilization container, and the mechanical device of after the sterilization cooling finishes sterilization container being released;

A pressure limiting valve 15, the highest counter-infiltration moisture vapour pressure when being used for keeping sterilization space internal pressure to be higher than sterilization;

A filtrated air generator 5 is used for forming sterilization space filtrated air malleation;

A vavuum pump 6, the negative pressure in sterilization space when being used for forming vacuum evaporation;

A vacuum buffer tank 7 is used for cushioning vacuum;

A sucking-off pump 8, when condensed water and (or) heat transfer medium is when liquid level reach a certain height in vacuum buffer tank, this pump is started working, and overcomes negative pressure, with condensed water and (or) heat transfer medium discharges, closes automatically after finishing;

A stop valve 24 is used for opening and closing being connected between filtrated air and the sterilization space;

A stop valve 26 is used for opening and closing being connected between vacuum buffer tank and the sterilization space;

A stop valve 12 is used for opening and closing being connected of heat transfer medium and sterilization space;

One cover automatic control system is used for controlling automatically the sterilization operation process;

One cover cleans (CIP) system on the spot, and being used for to what contact with heat transfer medium with food is that the surface, inside of equipment is cleaned automatically and sterilized.

This device forced convertion when heating heat transfer medium pressure greater than the pressure limiting valve operating pressure during greater than sterilization maximum moisture vapor press.

A kind of device second that is used to realize method of the present invention, being specially adapted to heat transfer medium is the situation of steam, compares with the device first, it is characterized in that comprising in addition:

A pressure-reducing valve 44 connects source of high pressure steam and steamdrum;

A steamdrum 1 is connected between sterilization container and the pressure-reducing valve, is used for cuisine steam stability of flow steam pressure;

This device forced convertion when heating, pressure-reducing valve export pressure greater than the pressure limiting valve operating pressure during greater than sterilization maximum moisture vapor press.The steam that pressure limiting valve is discharged can be used as indirect steam and recycles.

A device the third that is used to realize method of the present invention, being specially adapted to heat transfer medium is gas, for example the situation of carbon dioxide, nitrogen, air etc. is compared with the device first, it is characterized in that comprising in addition:

A gas compressor 17 is used for forming the pressure of heat transfer medium;

A gas heater 45 is used for heating heat transfer medium;

A gas cooler 46 is used for the Cooling Heat Transfer medium;

A triple valve 14 connects sterilization space, heat transfer medium heater and heat transfer medium cooler, is used for changing the heating and the cooling of heat transfer medium;

A gas buffer jar 42 is used for cushioning the flow and the steady pressure of heat transfer medium;

A gas purifier 43 is used for purifying the heat transfer medium after the compression, thoroughly removes wherein greasy dirt and peculiar smell

This device forced convertion when heating, compressor output services pressure greater than the pressure limiting valve operating pressure during greater than sterilization maximum moisture vapor press.Through the gas that pressure limiting valve is discharged,, can recycle if valuable.

A kind of device fourth that is used to realize method of the present invention, be applicable to that heat transfer medium is a liquid, comprise water-insoluble liquid such as grease, water and the aqueous solution (for example salt solution, soup juice), be specially adapted to the water-insoluble liquid heat-transfer medium, compare with the device first, it is characterized in that comprising in addition:

A heat transfer medium storage tank 9 is used for storing heat transfer medium, the heat transfer medium that the heat transfer medium that acceptance recycles and the separator of steam reclaim;

A heat transfer medium heater 28 is used for heating heat transfer medium;

A heat transfer medium cooler 13 is used for the Cooling Heat Transfer medium;

A heat transfer medium pump 11 is used for carrying heat transfer medium to enter the sterilization of high pressure sterilization space, forms the forced convertion to solid food;

A heat transfer medium clarifier 16 is used for filtering heat transfer medium, and heat transfer medium can be recycled;

A stop valve 10 is connected the heat transfer medium tank bottom, when heat transfer medium is water-insoluble liquid, is used for getting rid of the water and the aqueous solution in tank bottom;

An evacuated tube 27, be installed in the heat transfer medium tank top, for water-insoluble heat transfer medium, be used for getting rid of from solid food, take out of in the sterilization process a small amount of through becoming the moisture of steam after the pressure limiting valve step-down, for the water or the aqueous solution, be used for discharging through becoming that part of moisture of steam after the pressure limiting valve step-down;

A stop valve 47 connects vacuum buffer tank and heat transfer medium and adds inlet, is used for replenishing the heat transfer medium loss;

A check-valves 29 connects heat transfer medium storage tank and vacuum sucking-off pump, is used for preventing that gas and liquid flow backwards in vacuum buffer tank in the heat transfer medium storage tank;

This device is specially adapted to water-insoluble heat transfer medium, as grease, because there is not phase transformation in grease in the heating and cooling process, does not have evaporation process, can not cause energy loss, and many grease kinds are highly heat-resistant processing.As heat transfer medium, after through the pressure limiting valve step-down, have the part water evaporates for water or the aqueous solution, cause energy loss.The output pressure of this matching requirements heat transfer medium delivery pump is higher.This device forced convertion when heating, heat transfer medium delivery pump output pressure greater than the pressure limiting valve operating pressure during greater than sterilization maximum moisture vapor press.

A kind of device penta that is used to realize method of the present invention, be applicable to that heat transfer medium is a liquid, comprise water-insoluble liquid such as grease, water and the aqueous solution (for example salt solution, soup juice), being specially adapted to heat transfer medium is the water or the aqueous solution, compare with the device fourth, it is characterized in that comprising in addition:

An air compressor 4, the air pressure that maximum moisture vapor is pressed when being used for forming enclosure space greater than sterilization, and be the air source with the filtrated air;

A compressed air cleaner 3 is used for thoroughly removing greasy dirt and peculiar smell in the compressed air;

An air compressor basin 2 is used for the buffer compression air;

A stop valve 23 connects sterilization space and compressed air surge tank, and effect is keying sterilization space and being connected of compressed air surge tank;

A check-valves 22 connects sterilization space and compressed air surge tank, and effect is that heat medium flows backwards in the compressed air surge tank when preventing sterilization;

When this device heats in forced convertion, the output pressure of heat transfer medium delivery pump greater than compressed air pressure greater than the pressure limiting valve operating pressure the maximum vapour pressure of moisture during greater than sterilization, compressed air surge tank and the heat transfer medium storage tank balance that keep-ups pressure.Though the heat transfer medium delivery pump exit net pressure of this device is very high, because inlet pressure is also very high, both differences are little, and are therefore less demanding to the pressure head of heat transfer medium delivery pump itself.

The in short-term continued operation of food in a plurality of sterilization operation position of---the long-time in enormous quantities operation of pressure sterilizer intermittence is compared, and method of the present invention is by each sterilization relatively small amount---normally a bale capacity---reaches certain operating efficiency with traditional food high temperature disinfection equipment.So the practicality and the sterilizing time of method of the present invention, it is closely related just to reach the required heat transfer time of sterilization temperature.And the profile of heat transfer time and food is closely related.

The relation of heat transfer time and solid food profile can be calculated by thermal conduction study and obtain concrete data.Computational methods are from: " the food engineering principle first volume " chapter 2 the 3rd joint Beijing such as (: light industry publishing house, 1985) Wuxi Light Industry College.Relevant basic data from: " food frequently-used data handbook first (and food frequently-used data handbook write the group Beijing: Chinese food publishing house, 1985) and " Food Science handbook III a piece of writing (japanese food science handbook editorial board Beijing: light industry publishing house, 1989);

Sterilization diabatic process of the present invention is that heat transfer medium is formed to the heat conduction of inside the heat convection and the food surface of food surface, and wherein the latter is the heat transfer governing factor, and is that typical unstable is conducted heat, and meets the differential equation of unsteady heat transfer:

\frac{&PartialD; T}{&PartialD; t} = α (\frac{{&PartialD;}^{2} T}{&PartialD; x^{2}} + \frac{{&PartialD;}^{2} T}{&PartialD; y^{2}} + \frac{{&PartialD;}^{2} T}{&PartialD; z^{2}}), α = \frac{λ}{ρC},

α---temperature diffusivity, λ---thermal conductivity factor, ρ---proportion, C---specific heat capacity.For finding the solution this differential equation, can be reduced to spherical, cylindric and round sheet to the shape of food, can simplify the differential equation like this, obtain finding the solution of accurate number form formula:

---the accurate number of overheated surplus temperature, T _f---the thermostatic medium temperature, T---any time the arbitrfary point temperature, T ₀---initial temperature; Bi---finish wet accurate number (Biotnumber); F ₀---Fourier number (Fourier number); L ₀---the accurate number of geometric similarity, expression relative position.Finally carry out data computation by spheroid, cylinder and dull and stereotyped unsteady heat conduction line chart.About Object Selection, the solid food primary raw material of pasteurization is meat, vegetables usually, comparatively speaking, vegetables water content height, heat transfer coefficient is big, and therefore selecting the little meat of heat transfer coefficient for use is object, comprises lean meat and fat.Fat is one of kind of heat transfer coefficient minimum in the common food.Thermal conductivity factor, specific heat capacity, proportion such as the table 1 of lean meat and fat.

Analyze the solid food Common Shape, relevant appearance and size is set as follows: granule state food, if turn to spheroid, φ=0.2～2.6cm; Strip food is reduced to elongated cylinder, L=3cm, φ=0.2～1.0cm; Sheet-like food is reduced to short cylinder, δ=0.2～1.0cm, and φ=3cm is referring to Fig. 6.Relevant temperature conditions, initial temperature: food temperature is 60 ℃ after the preliminary treatment,

Table 1

Index	Thermal conductivity factor (W/mK)		Specific heat capacity (kJ/kgK)		Proportion (kg/m ³)
Index	Thermal conductivity factor (W/mK)		Specific heat capacity (kJ/kgK)		Proportion (kg/m ³)		Kind	Lean meat	Fat	Lean meat	Fat	Lean meat	Fat
Data	??0.40	??0.17	??3.40	??2.63	??1070	??950	Kind	Lean meat	Fat	Lean meat	Fat	Lean meat	Fat

Internal and external temperature is evenly distributed; The heat transfer medium temperature: 180 ℃ of heat transfer medium temperature, because the forced convertion effect, setting remains unchanged with the heat transfer medium temperature of Food Contact, under conditions of forced convection, this setting can be satisfied by approximate; Purpose central temperature and time: 140 ℃/2s, as the heating terminating point.Can calculate the accurate number of overheated surplus temperature like this

(180-60)=0.33.Therefore the required heat transfer Time Calculation of the temperature that achieves the goal is directly connected to the live load and the operating efficiency of forced heat-exchanging ultra high temperature sterilization, respectively to the difform food required heat transfer Time Calculation of temperature that achieves the goal.For granular food product, be reduced to spheroid, and the unsteady heat conduction differential equation of spheroid is:

R---calculation level radius.And

m = \frac{λ}{αR} = \frac{1}{Bi} = 0,

Thermal conductivity factor λ=0.40W/mK, α=250-300W/K: the accurate number L of the geometric similarity of center ₀=r/R=0; By

Find F from spheroid unsteady heat conduction line chart ₀=0.20.Because F ₀=at/R ², then:

t = \frac{F_{0} ρC φ^{2}}{4 λ}

ρ---proportion; C---specific heat capacity; φ---diameter.The substitution calculation of parameter can obtain lean meat: t=0.76 φ ², for fat: t=1.22 φ ²For strip food, be reduced to elongated cylinder, can regard the infinitely great dull and stereotyped intersection that infinitely long cylinder and thickness equal cylinder height as.Then The unsteady heat conduction differential equation of infinitely long cylinder is: The infinitely great dull and stereotyped unsteady heat conduction differential equation is: And for flat board, i.e. the strip meat of She Dinging, the thickness δ=3cm of elongated cylinder, it is imitative that to decide t be 2min, then:

F_{0} = \frac{λt}{4 ρC φ^{2}}

=0.0037 → 0,

So only consider infinitely long cylinder The calculating of similar granular food product,

t = \frac{F_{0} ρC φ^{2}}{4 λ} .

Same m=0, L ₀=0, by

Find F from cylinder unsteady heat conduction line chart ₀=0.25.The substitution calculation of parameter can obtain lean meat: t=0.94 φ ², fat: t=1.53 φ ²For sheet-like food: computational methods are identical with strip food.For cylinder, because φ=3cm makes

F_{0} = \frac{λt}{4 ρC φ^{2}} = 0.0037 &RightArrow; 0,

So just only consider infinitely great dull and stereotyped The calculating of similar granular food product,

t = \frac{F_{0} ρC δ^{2}}{4 λ} .

Same m=0, L ₀=0, by

Find F from dull and stereotyped unsteady heat conduction line chart ₀=0.67.The substitution calculation of parameter can obtain lean meat: t=2.54 δ ², fat: t=6.97 δ ²We have just drawn the relation of heat transfer time and product dimensions under the following meat different size shape of imposing a condition like this.Referring to Fig. 7, Fig. 8, Fig. 9.Method of the present invention on mode of heating by big heat transfer temperature difference conduct heat (120 ℃ of initial temperature differences stop 40 ℃ of the temperature difference), the direct of heat transfer medium and solid food contact and forced convertion realizes quick heat exchange, makes the solid food temperature that achieves the goal at short notice.Can calculate from top result, in forced convertion begins back 20s, reach the desired size of sterilization conditions and be not more than 0.52cm respectively, 0.47cm, 0.21cm at down granular, the strip of imposing a condition, sheet fat; In 60s, reach the desired size of sterilization conditions and be not more than 0.91cm, 0.81cm, 0.38cm respectively; In 120s, reach the desired size of sterilization conditions and be not more than 1.28cm, 0.92cm, 0.53cm respectively.But exist the situation that some help conducting heat in actual applications, make the temperature that achieves the goal be lower than theoretical computing time needed heat time heating time.Because: the heat transfer coefficient of most solid food is more much higher than fat; Usually the solid food surface configuration is irregular, and the slit is usually arranged, and has increased heat transfer area greatly, and actual heat transfer rate is accelerated; Heat transfer medium might be penetrated into food inside, by convection current, increases heat transfer rate; Adipocyte may be partly dissolved and break when high temperature heats, and increases heat transfer rate.Therefore, actual conditions more help application of the present invention, that is to say that forced convertion is shorter heat time heating time under the wider or certain product dimensions of size range of the solid food that method of the present invention adapts under certain sterilization temperature and the time conditions.Under usual conditions, 15s can carry out the processing of sterilization heat time heating time to most of small size solid food kinds to the forced convertion of 90s.

The moisture loss of decompression evaporation also is related to the using value of method of the present invention in the temperature-fall period.Sterilization finishes 160 ℃ of the mean temperatures of back meat, 100 ℃ of the mean temperatures of meat behind the atmospheric equilibrium, and evaporation latent heat is in the time of 120 ℃: 2205.2kJ/kg, the thermal capacitance C=3.4kJ/kgK of meat.Estimate when reaching with atmospheric equilibrium after the per kilogram meat ultra high temperature sterilization 0.085 kilogram of transpiring moisture easily by heat balance.100 ℃ of the mean temperatures of meat under the atmospheric equilibrium state, 45 ℃ of mean temperatures under 0.081 atmospheric pressure, water evaporation latent heat in the time of 80 ℃ is: 2307kJ/kg, the thermal capacitance C=3.4kJ/kgK of meat estimates per kilogram meat 0.081 kilogram of meat transpiring moisture when reaching atmospheric equilibrium easily by heat balance.As can be known in the step-down cooling procedure after sterilization, meat approximately will lose 17% moisture by top two estimations.Vegetables have bigger thermal capacitance, and moisture loss is 15～20%.In the thermal ripening process of meat, generally will lose 30～50% moisture under normal conditions, vegetables generally will lose 10～80% moisture under different cultivars, processing intensity and seasoning intensity in the process as dish.From food technology, moisture loss belongs to the acceptable scope in the cooling procedure of method for disinfection of the present invention.In addition, can be by in pretreatment process control heating and processing intensity, make the moisture that enters packaged products at last reach food due water content when edible to the method such as control of reserving of the removal of moisture.If the moisture of food is most important to food quality, can adopt the cooling of reduction vaporization radiating and cooling, and adopt cryogenic heat transfer medium direct forced-convection heat transfer cooling cooling.

The production efficiency of method of the present invention also is related to practicality of the present invention.Production capacity estimation when adopting method of the present invention to produce to typical small size solid food is as follows.Ultra high temperature sterilization: 20～60s, other process operations time 20s, the total working time is 40～80s, and setting each sterilization container displacement volume is 500 grams, and every unit has 10 sterilization heads, then per hour working ability is 450～900 bags, promptly 0.26～0.45 ton, according to 2 classes of meters every day, per tour 6 hours, produce 2.7～5.4 tons daily, produce 810～1620 tons per year.This production efficiency has industrial application value.Simultaneously, in order to raise the efficiency, can also be by the sterilizations simultaneously of many containers, referring to Figure 12, after the sterilization of perhaps big capacity sterilization container, aseptic subpackaged after packing again, can enhance productivity greatly.In addition, adopting the bull high efficiency disinfection equipment of the continuous rotary of method of the present invention also is feasible on know-why.

Though the sealing sterilization space of equipment will tolerate the pressure that is up to 12atm and the vacuum of the minimum 0.07atm of reaching, the food of but the each sterilization relatively small amount of the present invention---normally a bale capacity---, therefore the sterilization spatial volume is very little, for example, in the example of the above-mentioned sterilization of phase weekly 500 grams, the diameter of sterilization container only is 8-15cm under the normal condition, because the wall thickness of pressure vessel and the volume size negative correlation of equipment only need normal physical dimension just can tolerate these conditions of work.This point means littler equipment volume, and manufactured materials still less also means lower manufacturing cost.

On apparatus sanitation was safeguarded, the volume that surrounds owing to the equipment inner face with food and heat transfer medium contact portion was very little, was easy to realize that CIP cleans and the hot-air sterilization.

The temperature control that the automatic control of this device relates to, pressure control, liquid level control, valve opening and closing control, operating time control, parts Stroke Control or the like all are conventional autocontrol methods, can control by microcomputer, common automatic control professional and technical personnel just can solve the automatic control technology problem of device of the present invention.

Make the function of the mechanical device that relative motion also seals between sterilization head and the sterilization seat can resolve to three aspects: the location that is the direction of motion on the one hand is accurate to guarantee that both are sealed and matched, being the driving that both separate and close up motion on the one hand, is the locking device that the opposing of sealing back is up to the pressure of 12atm on the one hand.Location guide can be adopted in direction location, matches with guide rod axle sleeve on the sterilization head by the circumferential uniform many guide rod shafts that are fixed on the member that is connected as one with the sterilization seat, accurately limits the motion of sterilization head.Referring to Figure 13 Figure 14 Figure 15.The driving of the motion that both separate and close up can adopt the rack-and-pinion device to finish, tooth bar is fixed on the sterilization head along a sterilization direction of motion, the stressed bearing of driven wheel and motor and decelerator are fixed on the member that is connected as a single entity with the sterilization seat, and gear rotates, and drive the motion of sterilization head.The common mechanical major personnel of the power of rack-and-pinion and transmission device can implement design.Referring to Figure 18 Figure 19.The locking of sterilization head and sterilization seat can be by (the sterilization head radially) feeding be arranged radially the protrusion platform that acts on the sterilization head of the circumferential uniform a plurality of eccentric wheels of bearing fixing on the member that is connected as a single entity with the sterilization seat perpendicular to the similar ring flange of a sterilization pressure resultant direction realize.Working method is, after sterilization head and sterilization seat closed up, in the face of the protrusion platform on the sterilization head, radial feed was to its top with the minimum diameter direction for eccentric wheel, rotation, and diameter becomes greatly gradually, locks the sealing of sterilization head and sterilization seat.During work, sterilization space internal pressure increases the stressed back of eccentric wheel eccentric wheel frictional force, and self-locking is not rotated, and guarantees that the sterilization space does not produce leakage.After sterilization and cooling finish, the eccentric wheel reverse rotation, the sealing of unclamping sterilization head and sterilization seat, drawing back in the footpath, finishes the action of one-period.Referring to Figure 16 Figure 17.Eccentric driving and transmission speed reducer structure, common mechanical major personnel can implement design.

With the mechanical device that sterilization container pushes, locatees and releases, common Machine Design personnel can finish.

The related equipment of device of realizing method of the present invention adds that combination just can form unit to sterilization container input and output conveyer belt through equipment, and this combination is that common chemical industry and food apparatus professional just can design and finish.And being this unit, the subject matter that relates to the using value of this method how to be connected with aseptic packing system.

The packaged form that adopts the solid food of method sterilization of the present invention can be soft vacuum package, antivacuum flexible package, semi-rigid packing (for example paper plastic combined package), hard packing (for example vial and can).Preferably adopt hard material filling with inert gas packing for the Chinese meal that adopts method sterilization processing of the present invention, relatively adopt the vacuum packaging of soft material, in storage and transport process, do not have the external pressure pressuring action, can reduce the mass transfer between the different solid foods and organize flavor quality that compression damage causes and the reduction of physics organoleptic quality.

The sterile filling system of can and forced heat-exchanging ultra high temperature sterilization of the present invention system are combined with and may obtain optimal effect.For example: preliminary treatment food → forced heat-exchanging ultra high temperature sterilization → atmospheric evaporation cooling → can sterile filling → flowing water cooling → finished product.Adopt such system in combination can cancel the heat transfer medium cooling system and the vacuum system of disinfection equipment, sterilization process closely is connected with packaging process, packs while hot, and the part evaporation process is still being carried out after can, naturally form vacuum after the sealed cans, need not to vacuumize or filling with inert gas.

Ultra high temperature sterilization unit and the sterile packaging machine of using method of the present invention can adopt following fit form: a plurality of sterilizations of described unit sterilization seat combined parallel is arranged, importing and exporting both sides is sterilization container entrance conveyor and exit conveyor, and has housing to go along with sb. to guard him respectively.Other relevant equipment are combined among another housing, are connected by a pipeline and a sterilization sterilization seat.Pretreated food is delivered to a sterilization sterilization seat combination porch by the sterilization container entrance conveyor, send into the sterilization operation position by the mechanical device that sterilization container pushes, locatees and releases, after sterilization finishes, the mechanical device that is pushed, locatees and released by sterilization container is released and is entered exit conveyor again, sterilization container is hooked on the exit conveyor, when arriving can funnel top, down uncovered, solid food enters in the sterile packaging machine filling tube by funnel by the deadweight tenesmus.Empty sterilization container enters process cycles after discharging through a device of removing to link up with.Keep the filtrated air malleation in the input and output conveyer belt housing.

A lot of solid food kinds and Chinese meal kind all have a certain proportion of soup juice, aborning, adopt method of the present invention sterilizing unit and can be used with liquid ultra high temperature sterilization equipment, solid and liquid part are distinguished sterilization from afterwards, when sterile filling, mix according to a certain percentage, can produce the solid food that has a certain proportion of soup juice.

Method of the present invention is compared with traditional solid food sterilization still high temperature sterilization method, greatly reduces sterilizing time and heating intensity, helps flavours in food products quality, exterior quality and organizes the raising of quality.

Here temperature curve and the heat intensity with foods packed in carton containers method for disinfection in the sterilization still of method for disinfection of the present invention and present routine compares.Can think according to thermal conduction study calculating above: heating-up time 48s, atmospheric evaporation and vacuum evaporation 15s within the process for sterilizing parameter area of method of the present invention, and with this as according to making the temperature curve of direct forced heat-exchanging ultrahigh temperature sterilization of solid food roughly.Contrast method be the 450g flexible packing products of Chinese style meat products the conventional sterilization process (Chinese style meat fast food temperature-gradient method heat sterilization technical study Liu Food Sciences 2001 such as the people of fighting, vol.22, No.8).As seen from Figure 10, directly the heating intensity of forced heat-exchanging ultrahigh temperature sterilization of solid food method is low more than conventional sterilization, and gap is huge.

Ultra high temperature sterilization helps the factor that food quality has two aspects.On the one hand, along with the rising of temperature, the increase of microorganism fatality rate is much higher than the increase of Food Chemistry reaction rate, and the possibility of sterilization of following short time of high temperature is provided, promptly when reaching commercial sterilising conditions, make harmful Food Chemistry reaction be reduced to minimum level.(data are taken from " Food Science handbook IV piece of writing japanese food science handbook editorial board Beijing: light industry publishing house among the figure by Figure 11,1989) as can be seen the fatality rate of themoduric (among the figure be example with the bacillus stearothermophilus) count the constant straight line compare than the velocity constant of chemical reaction straight line of most of Food Chemistries reactions more precipitous, more responsive to temperature.The lethal temperature coefficient Q of bacillus stearothermophilus _{Δ T ℃}=10, be higher than the temperature coefficient Q of most of enzymatic reactions ₁₀The Q of value 1.4～2.0 and most of biologicallies ₁₀Value 2.0～2.5 has also illustrated this problem.(microorganism lethal temperature coefficient:

m ₁And m ₂---T ₁And T ₂Under heat treatment fatal rate constant; t ₁And t ₂---T ₁And T ₂Under thermal death time.The chemical reaction temperature coefficient:

Q_{10} = \frac{K_{2}}{K_{1}},

K ₁And K ₂---T ₁And T ₂Under velocity constant of chemical reaction, T ₁-T ₂=10).Therefore, have reason to think after method of the present invention is for the sterilization of solid food flavor quality, exterior quality and organize the raising of quality that obvious effect is arranged.

Method of the present invention is in the forced convertion heating process of sterilization, as long as heat transfer medium oxygen-free gas, food just can not contact oxygen, and oxidation reaction is restricted, and is also favourable to improving food quality.

Sterilization technology is the core technology of food processing, the The Technology of The UHT of liquid food makes liquid food have more kind, better quality, longer shelf life, to liquid food industry, comprise dairy industry, fruit drink industry, vegetable protein beverage industry etc., brought revolutionary variation.Ultrahigh temperature sterilization of solid food method of the present invention can be selected different heat transfer mediums for use, have varietal adaptation widely, might change the situation of present canned solid food processing industry, increase new kind, improve the quality that kind is arranged, prolong the shelf life of existing product.

Method and apparatus of the present invention is specially adapted to the especially sterilization of Chinese style cooking of Chinese meal.Resolve the typical process process of Chinese style cooking:

The frying process of most of Chinese meals is no more than 1～3min, be heated to very high temperature even near burning-point (200～300 ℃) as a large amount of oil (recycling usually) of cooking, by strong stirring oil bath food is heated rapidly, basically be a high temperature, short time (food temperature that water content is high is impossible above 100 ℃ certainly) heating process, preserved local flavor and the nutritional labeling in the food on the certain degree.Adopt grease can simulate above-mentioned technical process to a great extent as the ultra high temperature sterilization device of the present invention of heat transfer medium.Simultaneously because the tradition of Chinese food culture " meat chopped into small pieces of eating no rice but is of finest quality is not minded carefully ", many solid foods are all processed traditionally that volume is very little, usually particle diameter is no more than 1.0cm, the strip diameter generally is no more than 0.6cm, sheet thickness is no more than 0.4cm, is particularly suitable for the forced heat-exchanging ultra high temperature sterilization.

The direct forced heat-exchanging method for disinfection that with water or soup juice is heat transfer medium is more suitable to some light food kinds, might greatly enrich the kind of canned clear water vegetables and fruit, improves the clear water vegetables that produce now and the quality of fruit variety.

The sterilization that the direct forced heat-exchanging method for disinfection that with gas is heat transfer medium is some food---for example low water content thermal sensitivity raw-food material---provides unique method.Method of the present invention also can be used for the processing of traditional tinned food and some foreign foods kinds fully, and is expected to improve significantly the quality of product.

Description of drawings

Fig. 1 is the system works schematic diagram of device first, 21-sterilization container among the figure, 19-sterilization head, 25-sterilization seat, 18-sealing ring, the 20-network structure, 15-pressure limiting valve, 5-filtrated air generator, 6-vavuum pump, 7-vacuum buffer tank, 8-sucking-off pump, 24-stop valve, 26-stop valve, 12-stop valve;

Fig. 2 is the system works schematic diagram of device second, 44-pressure-reducing valve among the figure, 1-steamdrum, all the other same Fig. 1;

Fig. 3 is the system works schematic diagram of device third, 17-gas compressor, 45-gas heater, 46-gas cooler, 14-triple valve, 42-gas buffer jar, 43-gas purifier, all the other same Fig. 1;

Fig. 4 is the system works schematic diagram of device fourth, 9-heat transfer medium storage tank among the figure, 28-heat transfer medium heater, 13-heat transfer medium cooler, the 11-heat transfer medium pump, 16-heat transfer medium clarifier, 14-triple valve, 27-evacuated tube, the 48-heat transfer medium pump, the 47-stop valve, 29-check-valves, all the other same Fig. 1;

Fig. 5 is the system works schematic diagram of device penta, 4-air compressor among the figure, 3-compressed air cleaner, 2-air compressor, 23-stop valve, 22-check-valves, all the other same Fig. 4;

Fig. 6 is the shape of food rough schematic view, a-spheroid among the figure, b-elongated cylinder, c-cylinder;

Fig. 7 is the diameter of granular meat and the required heat transfer time chart of temperature that achieves the goal.Abscissa is the diameter of granular meat, and unit is cm, and ordinate is the required heat transfer time of temperature of achieving the goal, and unit is min, and d is fatty curve, and e is the lean meat curve;

Fig. 8 is the diameter of strip meat and the required heat transfer time chart of temperature that achieves the goal.Abscissa is the diameter of strip meat, and unit is cm, and ordinate is the required heat transfer time of temperature of achieving the goal, and unit is min, and f is fatty curve, and g is the lean meat curve;

Fig. 9 is the thickness of sheet meat and the required heat transfer time chart of temperature that achieves the goal.Abscissa is the thickness of sheet meat, and unit is cm, and ordinate is the required heat transfer time of temperature of achieving the goal, and unit is min, and h is fatty curve, and i is the lean meat curve;

Figure 10 is the ultra high temperature sterilization temperature curve and the sterilization still conventional sterilization temperature curve comparison diagram of method of the present invention.Abscissa is a sterilizing time, and unit is min, and ordinate is a temperature, and unit is ℃; H is a ultra high temperature sterilization solid food surface temperature curve, and i is a ultra high temperature sterilization solid food central temperature curve, and j is a conventional sterilization package interior side temperature curve, and k is a food central temperature curve in the conventional sterilization packing;

Figure 11 is the microorganism lethal temperature coefficient and the synthermal graph of a relation of various food rate constants of bacillus stearothermophilus.Abscissa is the inverse of absolute temperature, and unit is 1/K * 10 ³, ordinate is a rate constant, unit is 1/min;

Figure 12 is the situation of many containers sterilization simultaneously in sterilization head and the combination of sterilization seat, 21-sterilization container among the figure, 19-sterilization head, 25-sterilization seat;

Figure 13 is the profile of sterilization head and the combination of sterilization seat, 21-sterilization container among the figure, 19-sterilization head, 25-sterilization seat, 18-sealing ring, 20-network structure, 30-guide rod shaft, 31-vacuum inlet, 32-filtrated air inlet;

Figure 14 is the A-A view of Figure 13,21-sterilization container among the figure, 19-sterilization head, 25-sterilization seat, 33-eccentric wheel;

Figure 15 is the B-B view of Figure 13,30-guide rod shaft among the figure, 19-sterilization head, 20-network structure, 25-sterilization seat, 33-eccentric wheel;

Figure 16 is eccentric part sectioned view, 25-sterilization seat among the figure, 33-eccentric wheel, 19-sterilization head, 18-sealing ring;

Figure 17 be the D-D of Figure 16 to view, 33-eccentric wheel among the figure, 19-sterilization head, 25-sterilization seat;

Figure 18 is the rack-and-pinion schematic diagram of device that drives sterilization head and the relative motion of sterilization seat, 49-heat transfer medium outlet pipeline among the figure, 50-tooth bar, 51-key, 52-gear drive axle, the 53-gear, 54-sealing ring gland, 48-trip bolt, the 55-dynamic seal ring, 25-sterilization seat, 30-guide rod shaft, 19-sterilization head;

Figure 19 be the C-C of Figure 18 to view, 49-heat transfer medium outlet pipeline among the figure, 50-tooth bar, 52-gear drive axle, 53-gear, 54-sealing ring gland, 48-trip bolt, 55-dynamic seal ring, 25-sterilization seat;

Figure 20 is the system in combination of each equipment of device of method of the present invention, and system in combination and sterile packaging machine are united the system schematic of use, 21-sterilization container among the figure, 38-entrance conveyor, 36-exit conveyor, the 37-sterile packaging machine, the 41-finished product, 34-shell, 38-entrance conveyor shell, 39-exit conveyor shell, the 44-shell;

Figure 21 is the device of method of the present invention and cooperating of sterile packaging machine.21-bacterium container among the figure, 39-exit conveyor shell, 36-exit conveyor, 40-loading hopper and sterile packaging machine feed pipe.

Further narrate the present invention again with reference to accompanying drawing:

The job step of device first is described with reference to accompanying drawing 1.Incipient stage: valve 12 valves 26 cut out, valve 24 is opened, the filtrated air malleation that keeps the sterilization zone, sterilization 19 runs to the extreme higher position, sterilization container 21 enters between sterilization 19 and the sterilization seat 25, sterilization 19 move down hold sterilization container 21 and and sterilization seat 25 draw close, seal fully by sealing ring 18; The forced convertion heating period: shut off valve 24; Open valve 12 high pressure heat transfer mediums through entering the sterilization space; There is a network structure 20 sterilization 19 interior sterilization container 21 top, cover the uncovered of sterilization container, and food can not moved with heat transfer medium; The effect of pressure limiting valve 15 is the high-moisture vapour pressures when keeping heat transfer medium pressure in the sterilization space to be higher than sterilization in the sterilization space; Cooling stage: shut off valve 12 stops forced-convection heat transfer; Open valve 26, progressively reduce the pressure in the sterilization space, open fully, reach the pressure that is not higher than 0.07atm, food decompression evaporation, rapid radiating and cooling to 40～50 ℃ up to valve 26; Ending phase: valve 24 is opened, and keeps sterilization interior volume filtrated air malleation, and the sterilization head is moved upwards up to the extreme higher position then, and the food that sterilization container 23 is being adorned after the sterilization leaves the sterilization space, enters the aseptic packaging operation.This moment, device was got back to the initialization state again, the work of beginning next cycle.

Reference system accompanying drawing 2 illustrates the job step of the method for device second.Incipient stage: operation is identical with the device first; The forced convertion heating period: shut off valve 24; Open valve 12 heat transfer mediums and enter the sterilization space, behind the food forced heat-exchanging, discharge through pressure limiting valve; Cooling stage: shut off valve 12 stops forced-convection heat transfer; Open valve 26, progressively reduce the pressure in the sterilization space, open fully, reach the pressure that is not higher than 0.07atm, food decompression evaporation at this moment, radiating and cooling to 40～50 ℃ rapidly up to valve 26; Ending phase: valve 24 is opened, and keeps sterilization interior volume filtrated air malleation, and the sterilization head is moved upwards up to the extreme higher position then, and the food that sterilization container 23 is being adorned after the sterilization leaves the sterilization space, enters the aseptic packaging operation.Discharged steam can be recycled.This moment, device was got back to the initialization state again, the work of beginning next cycle.

The job step of device third is described with reference to accompanying drawing 3.Incipient stage: valve 12 valves 26 valves 29 cut out, valve 24 is opened, and keeps sterilization zone filtrated air malleation, and sterilization 19 runs to the extreme higher position, sterilization container 21 enters between sterilization 19 and the sterilization seat 25, sterilization 19 move down hold sterilization container 21 and and sterilization seat 25 seal fully; The compression that is used as the gas process compressor 17 of heat transfer medium reaches certain pressure, again through a gas purifier 43, thoroughly remove greasy dirt and peculiar smell in the gas, enter surge tank 42 then, the effect of surge tank is the flow and the pressure of stabilizing gas heat transfer medium.The forced-convection heat transfer stage: shut off valve 24; Open valve 12 heat transfer mediums and enter the sterilization space, behind the food forced heat-exchanging, through the pressure-reducing valve discharging; Cooling stage: first method, after the pasteurization process is finished, shut off valve 12 stops forced-convection heat transfer, opens valve 26, progressively reduce the pressure in the sterilization space, open fully up to valve 26, reach the pressure that is not higher than 0.07atm, at this moment the food decompression evaporation, final temperature reaches 40～50 ℃, finish cooling, perhaps adopt second method, after the reduction vaporization cooling, open valve 12 once more, triple valve 14 connects cooler and sterilization space, and the cryogenic heat transfer medium lowers the temperature up to normal temperature food rapidly with the solid food in the sterilization container of flowing through, finish the sterilization process for cooling, perhaps do not adopt the third method by decompression evaporation cooling, shut off valve 12 not after the pasteurization process is finished, and make valve 14 connect cooler and sterilization spaces, the solid food of cryogenic heat transfer MEDIA FLOW in sterilization container makes food cool to normal temperature; The vapor portion of evaporation is condensate in the vacuum buffer tank 7, and assembles in the bottom, and after reaching certain liquid level, automatic control system starts heat transfer medium sucking-off pump 8 automatically, and heat transfer medium is discharged; Check-valves 29 prevents sucking-off pump 8 to quit work afterwards, and air flows backwards in vacuum buffer tank; Ending phase: for first kind of cooling means, after cooling finishes, shut off valve 26, open valve 24, keep sterilization interior volume filtrated air malleation, the sterilization head is moved upwards up to the extreme higher position, and sterilization container leaves the sterilization space, enters the aseptic packaging operation, perhaps for second the third cooling means, after cooling finishes, shut off valve 12, valve 24 is opened, keep sterilization interior volume filtrated air malleation, the sterilization head is moved upwards up to the extreme higher position then, and the food that sterilization container 21 is being adorned after the sterilization leaves the sterilization space, enters the aseptic packaging operation.This moment, device was got back to the initialization state again, the work of beginning next cycle.

The job step of device fourth is described with reference to accompanying drawing 4.Incipient stage: identical with the operating procedure of device third; The forced-convection heat transfer stage: shut off valve 24; Open valve 12, triple valve 14 is opened to and connects sterilization seat 25 and heat transfer medium heater 30, starts heat transfer medium delivery pump 11, heat transfer medium is heated to 100～190 ℃ through heater, enter the sterilization space, get rid of the air in the sterilization space, with food forced convertion forced heat-exchanging; Heat transfer medium is got back to heat transfer medium storage tank 9 after by heat transfer medium clarifier 16 filtration, purifications; The moisture that enters in the heat transfer medium basin drops to normal pressure, owing to be in superheat state, evaporation rapidly, steam is got rid of by evacuated tube 27, and condensed water discharges after then starting sucking-off by sucking-off pump 10 automatically when the moisture liquid level reach a certain height; Cooling stage: first method, after the pasteurization process was finished, shut off valve 12 stopped forced-convection heat transfer; Open valve 26, progressively reduce the pressure in the sterilization space, open fully up to valve 26, reach the pressure that is not higher than 0.07atm, at this moment food decompression evaporation, radiating and cooling to 100～40 ℃ rapidly is if vacuum is higher, final temperature reaches 40～50 ℃, finish cooling stage, perhaps adopt second method, after finishing a kind of all processes of method, open valve 12 once more, triple valve 14 connects cooler and sterilization space, and the solid food of cryogenic heat transfer MEDIA FLOW in sterilization container lowered the temperature up to normal temperature food rapidly, finish process for cooling, perhaps do not adopt the third method by decompression evaporation cooling, shut off valve 12 not after the pasteurization process is finished, and make valve 14 connect cooler and sterilization spaces, the solid food of cryogenic heat transfer MEDIA FLOW in sterilization container makes food cool to normal temperature; The steam of evaporation and remaining heat transfer medium separate in vacuum buffer tank 7, and assemble in the bottom, and after reaching certain liquid level, automatic control system starts heat transfer medium sucking-off pump 8 automatically, and heat transfer medium is sucked heat transfer medium storage tank 9; Check-valves 29 prevents that air and liquid flow backwards to vacuum buffer tank when sucking-off pump 8 quits work; Ending phase: for first kind of cooling means, after cooling finishes, shut off valve 26, valve 24 is opened, keep sterilization interior volume filtrated air malleation, the sterilization head is moved upwards up to the extreme higher position, and sterilization container leaves the sterilization space, enters the aseptic packaging operation, perhaps for second the third cooling means, after cooling finishes, shut off valve 12, valve 24 is opened, keep sterilization interior volume filtrated air malleation, the sterilization head is moved upwards up to the extreme higher position then, and the food that sterilization container 21 is being adorned after the sterilization leaves the sterilization space, enters the aseptic packaging operation.This moment, device was got back to the initialization state again, the work of beginning next cycle; How the character of heat transfer medium all is bound to occur the heat transfer medium loss in operating process, by opening valve 47 aseptic heat transfer medium is sucked vacuum buffer tank automatically, enters the heat transfer medium circulation, replenishes the heat transfer medium loss.

The job step of device penta is described with reference to accompanying drawing 5.Incipient stage: valve 12 valves 23 valves 26 valves 29 cut out, valve 24 is opened, and keeps sterilization zone filtrated air malleation, and sterilization 19 runs to the extreme higher position, sterilization container 21 enters between sterilization 19 and the sterilization seat 25, sterilization 19 move down hold sterilization container 21 and and sterilization seat 25 seal fully; The forced-convection heat transfer stage: shut off valve 24; Open valve 23, make the pressure of high-moisture vapour pressure when reaching above sterilization in the sterilization space, this pressure is generally 1～12atm; Open valve 12, triple valve 14 is opened to and connects sterilization seat 25 and heat transfer medium heater 30, starts heat transfer medium delivery pump 11, and heat transfer medium is heated to 100～190 ℃ through heater, enters the sterilization space, gets rid of the air in the sterilization space; Check-valves 22 does not flow to into compressed air line heat transfer medium; Heat transfer medium is got back to heat transfer medium storage tank 9 after by heat transfer medium clarifier 16 filtration, purifications; Cooling stage: first method, after food pasteurization process was finished, shut off valve 12 valves 23 stopped forced-convection heat transfer; Open valve 26, progressively reduce the pressure in the sterilization space, open fully up to valve 26, reach the pressure that is not higher than 0.07atm, 40～50 ℃ of the rapid evaporative heat loss coolings of food, finish cooling, perhaps adopt second method, after the evaporative heat loss cooling, open valve 12 once more, triple valve 14 connects cooler and sterilization space, the solid food of cryogenic heat transfer MEDIA FLOW in sterilization container, make food cool to normal temperature rapidly, finish cooling, perhaps do not adopt the third method by the decompression evaporation cooling, shut off valve 12 valves 23 not after the pasteurization process is finished, and making valve 14 connect cooler and sterilization space, the solid food of cryogenic heat transfer MEDIA FLOW in sterilization container makes the food cooling up to normal temperature; Ending phase: for first kind of cooling means, after cooling finishes, shut off valve 26, valve 24 is opened, keep sterilization interior volume filtrated air malleation, the sterilization head is moved upwards up to the extreme higher position, and sterilization container leaves the sterilization space, enters the aseptic packaging operation, perhaps for second the third cooling means, after cooling finishes, shut off valve 23 valves 12 in order, valve 24 is opened, keep sterilization interior volume filtrated air malleation, the sterilization head is moved upwards up to the extreme higher position then, and the food that sterilization container 21 is being adorned after the sterilization leaves the sterilization space, enters the aseptic packaging operation; This moment, device was got back to the initialization state again, the work of beginning next cycle;

What Figure 13 Figure 14 Figure 15 expressed is the structure composition of sterilization head and sterilization seat.The periphery of sterilization 19 is one and is all unitary housing with sterilization seat 25, and shown position is fixed with equally distributed 4 guide rod shafts 30, and the guide rod axle sleeve on the sterilization head cooperates with leader casing, can cooperate with sterilization seat 25 exactly when the sterilization head is moved up and down.31 of vacuum pipe inlet is arranged on the sterilization seat, filtrated air inlet 32, does not express on figure the compressed air inlet.During work, sterilization 21 rises to the extreme higher position, and as shown in phantom in Figure 13, sterilization container 21 enters the operating position from a side, and sterilization is left the operating position from opposite side again after finishing.

Figure 16 Figure 17 is the eccentric wheel fundamental diagram.Operation principle is, when sterilization 19 and sterilization seat 25 reach sealing station, the eccentric wheel 33 that eccentric shaft bearing is fixed on the sterilization seat 25 axially moves to a sterilization direction along it, behind the in-position, rotation, locking sterilization 19 and sterilization seat 25 do not occur leaking under 1～12atm when the effect that adds sealing ring 18 guarantees sterilization.After sterilization finished, the eccentric wheel rotation was unclamped, and retreats, and the sterilization head rises, the operation of beginning next cycle.

Figure 18 Figure 19 is the rack-and-pinion device fundamental diagram that drives sterilization head and the relative motion of sterilization seat.Tooth bar 50 be fixed on sterilization 19 a heat transfer medium outlet pipeline 49 that are connected as a single entity on, gear rotate to drive tooth bar and moves up and down, thereby drives

sterilization

19 and 25 relative motions of sterilization seat.For the stability that guarantees to move, a dynamic seal ring 55 is arranged between heat transfer medium outlet pipeline and sterilization seat, the position of sealing ring gland 54 fixed seal rings, trip bolt 48 is used for fit sealing circle gland and sterilization seat.

Figure 20 is the system in combination of each equipment of device of method of the present invention, and system in combination and sterile packaging machine are united the system schematic of use.Working method is as follows: through the pretreated food branch sterilization container 21 of packing into, arrive a sterilization import through conveyer belt 38, push a sterilization operating position by the sterilization container pushing in device, enter sterilization process, after sterilization finishes, enter conveyer belt 36, obtain finished product 41 after sending into sterile packaging machine 37 aseptic packagings.Device housings is 34,56,39,57, what shell 34 inside held is the heat transfer medium storage tank, heat transfer medium pump, heat transfer medium heater, heat transfer medium cooler, heat transfer medium clarifier, vacuum buffer tank, vacuum buffer tank heat transfer medium sucking-off pump, compressed air surge tank and clarifier, pipeline, dynamical system and automatic

control system.Shell

56,39,57 inside are respectively entrance conveyor 38, exit conveyor 36 and sterilization head and the combination of sterilization seat.Enclosure guarantees integral asepsis when work.

Figure 21 is the present invention and sterile packaging machine bridging mode schematic diagram.The sterilization container 21 of finishing sterilization is fixed on the conveyer belt 36, when sterilization container runs to the top of filling tube 40 along with conveyer belt, and the uncovered reversing of sterilization container, food crashes in the can pipeline 40 by deadweight, enters packing container.

Claims

1. ultrahigh temperature sterilization of solid food method.This method may further comprise the steps:

(1) food for the treatment of sterilization enters an enclosure space;

2. device that is used to realize the method for claim 1, this device comprises:

A plurality of sterilization containers (21) are the container-like object of open-top, the bottom or all be solid food can not by and heat transfer medium can freely through network structure, be used in sterilization process, loading solid food through preprocessing;

The unlimited container-like member of an end face that is referred to as sterilization head (19);

The container-like member that end face that is referred to as sterilization seat (25) opens wide and can be sealed and matched with the sterilization head, sterilization head and sterilization seat can relative motions, sterilization container can enter between the two in the time of separately, and the sterilization space that two unlimited end faces seal by the airtight formation of sealing ring (18) when closing up also comprises sterilization container;

A network structure (20), being fixed on sterilization head inside, to cover sterilization container uncovered, heat transfer medium can freely pass through and food is intransitable, effect be when preventing the forced heat-exchanging pasteurization solid food along with heat transfer medium flows;

A pressure limiting valve (15), the high-moisture vapour pressure when being used for keeping sterilization space internal pressure to be higher than sterilization;

A filtrated air generator (5) is used for forming sterilization space filtrated air malleation;

A vavuum pump (6), the negative pressure in sterilization space when being used for forming vacuum evaporation;

A vacuum buffer tank (7) is used for cushioning vacuum;

A sucking-off pump (8), when condensed water and (or) heat transfer medium is when liquid level reach a certain height in vacuum buffer tank, this pump is started working, and overcomes negative pressure, with condensed water and (or) heat transfer medium discharges, closes automatically after finishing;

A stop valve (24) is used for opening and closing being connected between filtrated air and the sterilization space;

A stop valve (26) is used for opening and closing being connected between vacuum buffer tank and the sterilization space;

A stop valve (12) is used for opening and closing being connected of heat transfer medium and sterilization space;

One cover automatic control system is used for controlling automatically whole operating process of sterilization process;

3. one kind according to the described device of claim 2, and being specially adapted to heat transfer medium is the situation of steam, it is characterized in that comprising in addition:

A pressure-reducing valve (44) connects source of high pressure steam and steamdrum;

A steamdrum (1) is connected between sterilization container and the pressure-reducing valve, is used for cuisine steam stability of flow steam pressure;

This device forced convertion when heating, pressure-reducing valve export pressure greater than the pressure limiting valve operating pressure during greater than sterilization maximum moisture vapor press.

4. one kind according to the described device of claim 2, and being specially adapted to heat transfer medium is gas, and the situation of carbon dioxide, nitrogen, air etc. for example is characterized in that comprising in addition:

A gas compressor (17) is used for forming the pressure of heat transfer medium;

A gas heater (45) is used for heating heat transfer medium;

A gas cooler (46) is used for the Cooling Heat Transfer medium;

A triple valve (14) connects sterilization space, heat transfer medium heater and heat transfer medium cooler, is used for changing the heating and the cooling of heat transfer medium;

A gas buffer jar (42) is used for cushioning the flow and the steady pressure of heat transfer medium;

A gas purifier (43) is used for purifying the heat transfer medium after the compression, thoroughly removes wherein greasy dirt and peculiar smell;

This device forced convertion when heating, compressor output services pressure greater than the pressure limiting valve operating pressure during greater than sterilization maximum moisture vapor press.

5. one kind according to the described device of claim 2, is applicable to that heat transfer medium is a liquid, comprises water-insoluble liquid such as grease, water and the aqueous solution (for example salt solution, soup juice), is specially adapted to the water-insoluble liquid heat-transfer medium, it is characterized in that comprising in addition:

A heat transfer medium storage tank (9) is used for storing heat transfer medium, the heat transfer medium that the heat transfer medium that acceptance recycles and the separator of steam reclaim;

A heat transfer medium heater (28) is used for heating heat transfer medium;

A heat transfer medium cooler (13) is used for the Cooling Heat Transfer medium;

A heat transfer medium pump (11) is used for carrying heat transfer medium to enter the sterilization of high pressure sterilization space, forms the forced convertion to solid food;

A heat transfer medium clarifier (16) is used for filtering heat transfer medium, and heat transfer medium can be recycled;

An evacuated tube (27), be installed in the heat transfer medium tank top, for water-insoluble heat transfer medium, be used for getting rid of from solid food, take out of in the sterilization process a small amount of through becoming the moisture of steam after the pressure limiting valve step-down, for the water or the aqueous solution, be used for discharging through becoming that part of moisture of steam after the pressure limiting valve step-down;

A stop valve (47) connects vacuum buffer tank and heat transfer medium and adds inlet, is used for replenishing the heat transfer medium loss;

A check-valves (29) connects heat transfer medium storage tank and vacuum sucking-off pump, is used for preventing that gas and liquid flow backwards in vacuum buffer tank in the heat transfer medium storage tank;

This device forced convertion when heating, heat transfer medium delivery pump output pressure greater than the pressure limiting valve operating pressure during greater than sterilization maximum moisture vapor press.

6. one kind according to the described device of claim 4, is applicable to that heat transfer medium is a liquid, comprises water-insoluble liquid such as grease, water and the aqueous solution (for example salt solution, soup juice), and being specially adapted to heat transfer medium is the water or the aqueous solution; It is characterized in that comprising in addition:

An air compressor (4), the air pressure that maximum moisture vapor is pressed when being used for forming enclosure space greater than sterilization, and be the air source with the filtrated air;

A compressed air cleaner (3) is used for thoroughly removing greasy dirt and peculiar smell in the compressed air;

An air compressor basin (2) is used for the buffer compression air

A stop valve (23) connects sterilization space and compressed air surge tank, and effect is keying sterilization space and being connected of compressed air surge tank;

A check-valves (22) connects sterilization space and compressed air surge tank, and effect is that heat medium flows backwards in the compressed air surge tank when preventing sterilization.

When this device heats in forced convertion, the output pressure of heat transfer medium delivery pump greater than compressed air pressure greater than the pressure limiting valve operating pressure the maximum vapour pressure of moisture during greater than sterilization, compressed air surge tank and the heat transfer medium storage tank balance that keep-ups pressure.

7. one kind according to the sterilization head (19) of claim 2 and the composite set of sterilization seat (25), it is characterized in that comprising the cephalomotor location guide of accurate qualification sterilization, is used to lock the eccentric wheel with radial feed of sterilization head and sterilization seat and the rack-and-pinion device that drives sterilization head and the relative motion of sterilization seat.

8. one kind according to the described device of claim 6, and the circumferential uniform many guide rod shafts (30) that it is characterized in that being fixed on the member that is connected as one with sterilization seat (25) match with guide rod axle sleeve on the sterilization head (19), accurately limit the motion of sterilization head.

9. one kind according to the described device of claim 6, it is characterized in that tooth bar (50) is fixed on the heat transfer medium outlet pipeline that is connected as a single entity with sterilization head (19) on (49) along sterilization head (19) direction of motion, the stressed bearing of driven wheel and motor and decelerator are fixed on the member that is connected as a single entity with sterilization seat (25), gear (53) rotates, and drives sterilization head (19) motion.

10. one kind according to the described device of claim 6, the circumferential uniform one or more eccentric wheels (33) of the bearing fixing that it is characterized in that having radially (the sterilization head radially) feeding on the member that is connected as a single entity with sterilization seat (25), and the protrusion platform of similar ring flange on the sterilization head, after sterilization head (19) and sterilization seat (25) close up, eccentric wheel with the minimum diameter direction in the face of the protrusion platform on the sterilization head, radial feed is to its top, rotation, diameter becomes greatly gradually, the sealing of locking sterilization head and sterilization seat.