RU125024U1 - BRODSKY PASTERIZER - Google Patents

Abstract

Brodsky's pasteurizer is intended for pasteurization and cooling of milk and can be used on small-scale commercial farms, as well as dairies in the processing of replaceable volumes of milk from 2,000 liters to 20,000 liters.

The pasteurizer contains a supplementary tank of raw milk with a centrifugal circulation pump and a check valve, a recuperative plate heat exchanger of counter-flows of pasteurized and raw milk, a water-heating pasteurization tank (VPB) with a helical coil made of a thin-walled F40 tube with a length of 10 m, and one of the other themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes and related themes, and other, and other to get to the hearths and other, with the help of a combination of combi , as well as a sealed cylindrical tank-holder with a quick-release end cap and a thermal sensor electrically connected to a non-return valve. At the same time, the additional tank is connected through pipelines to the coil inlet through the centrifugal pump and the heat exchanger inlet pipes (raw milk direct flow), the output of which is connected to the inlet valve through the soaker. A gearmotor with a stirrer placed in the center of the airframe inside the heating elements and a screw coil is installed on the cover of the TBF. This increases the heat exchange between the heating elements and the flow of milk inside the screw coil, which increases the efficiency of the pasteurizer, reduces the overheating of heating elements, eliminates boiling water on their surface.

The pasteurizer allows for the recovery of heat and refrigeration flows in a plate heat exchanger to save up to 90% of electricity compared with direct heating of milk. Periodic washing and cleaning of the filling tank, separator, pump, valve, milk lines, including the screw coil, poses no problems and can be carried out including standard tampons-wads.

Description

Application area.

The utility model, the pasteurizer, is intended for heating (pasteurization) and subsequent cooling, mainly milk in the stream, as well as for pasteurization of beer, juices, and can be used at food industry enterprises, dairies and small-scale farms, with the release of sour cream, cream, kefir, cottage cheese with production volumes from 2000 to 20,000 liters per day.

The level of technology.

At present, devices based on a plate heat exchanger - regenerator (recuperator), through which counter flows of raw (cold) water are used, are used for pasteurization in the flow (heating up to 76 ° ... 92 °) and subsequent cooling with a capacity from 1000 l to 2000 l per hour. a) milk and pasteurized (hot) milk [1, 2, 3, 4, 5]. Milk heating can be carried out by heating elements with electric boiler [1, 2, 3, 4] through a coil or by rotary (vortex) centrifugal pumps [5] due to the conversion of the mechanical energy of electric pumps into heat energy. The disadvantage of the latter is high acoustic noise with a capacity of 1500 l / h from two powerful electric pumps (2 * 7.5 = 15 kW). The advantage of plate recuperative pasteurizers in the stream with electric boiler is high efficiency and energy saving, and the disadvantages are the complexity of washing, labor-intensive maintenance, the need for additional tanks of raw and pasteurized milk. These shortcomings have free capacitive baths for long pasteurization [6] with heating elements and artesian water, and also, pasteurization and refrigeration units [7] with heating elements, plumbing pre-cooling and freon after-cooling. Pasteurization of milk up to 2500 liters per shift and its cooling is carried out in a single tank [6, 7] with a volume of up to 2500 liters. There are no problems with its washing and maintenance, however, the direct heating of milk (without recovery) is a big drawback (about 0.1 ... 0.15 kWh per liter), although recuperative plate pasteurizers in the flow [1-5] save up to 85% electricity and processed up to 10,000 ... 20,000 liters of milk per shift.

An analogue to the proposed solution is the device [2, 3] for pasteurization IPKS-013R-2500P according to patent RU 2007146478, produced in Ryazan by the company Elf-4M, described in detail on the website www.elf4m.ru/passport ipks-013- 01.pdf [3].

The apparatus comprises equalizing (popolnitelny) tank raw milk with centrifugal circulating pump and a return valve, the regenerative plate heat exchanger of counter flow pasteurized and raw milk, water heating pasteurizing tank screw dairy coil, heating elements and associated water thermostat and a collecting coil - vyderzhivatel F60 4 m long with rolls of 1,5 m and the thermal sensor. At the same time, the additional tank is connected via pipelines to the inlet of the screw coil through a centrifugal pump and inlet pipes of the heat exchanger, and the outlet of the screw coil is connected to the return valve of the heat exchanger (countercurrent of pasteurized milk) through the return valve of the exchanger coil associated with the supplementary tank, and - the second plate heat exchanger - after-cooler, fed by a stream of ice water - with the output of the device. Thermal sensor coil - keeper is connected to the electrical inlet of the return valve. The device [2, 3] provides performance from 1000 to 2500 l / h, the level of heat energy recovery up to 80%, the temperature of the cooled product 4 °, the dwell time 16 ... 20 s at a power consumption of up to 46 kW, and 65 kW, pasteurization temperature 76 ... 92 °. Daily flushing of the device with alkali and acid in the circulation mode according to Passport [2] takes 30% of its operation time. 1 time in three days it is recommended to disassemble the coil soaker and piping (7 pcs.) With cleaning them with a tampon and a flexible cable. Plate recuperative and second refrigerated heat exchangers must be disassembled and mechanically cleaned once every six months or as they become clogged and performance is reduced.

The disadvantage of the analogue is a long helical milk coil, made of a double stainless pipe F20 * 1, 15 m long 10 turns F500. The coil is excessively long and it is not clear how to clean it during operation. In addition, coil coils are packed tightly (without gaps) in relation to each other. This impairs the heat exchange between milk and hot water due to natural convection, since around the coil is difficult to circulate water and closed coils exclude from heat exchange up to 30% ... 40% of the effective area, which requires a proportional elongation of the screw coil and complicates its washing.

The closest technical solution (prototype) is a pasteurization installation according to the patent RU 120541.

The installation comprises popolnitelny tank raw milk with centrifugal circulating pump and a return valve, the regenerative plate heat exchanger of counter flow pasteurized and raw milk, water heating pasteurizing tank with lid, screw coil made of a thin-walled tube F40, heating elements and associated water thermostat and volume cylindrical holder with thermal sensor connected to the electrical inlet of the return valve.

The screw coil of the prototype is made of pipe F40, AISI316, having a diameter D = 530 mm, a coil spacing h = 60 mm between the surfaces of the turns there is a gap h-D = 60-40 = 20 mm, which allows to participate in the heat exchange of the entire original cylindrical surface of the pipe. Unlike the analogue, the helical coil is easily cleaned from residual milk deposits with the help of standard foam foam wads F60x100, installed at the head of the coil, and a regular circulation pump.

The calculation of the thermodynamics of the screw coil given in the prototype [1] shows the ability to heat raw milk from practically 70 ° C to a water temperature of 80 ° C when the flow moves from inlet to outlet at a flow rate of 2000 l / h, but this calculation does not take into account the static state of the cooled "Stocking" water pipe that occurs around the coil turns. Natural circulating convection in a water-heating tank, consisting in raising hot water layers heated by heating elements inside the coil and lowering water-cooled layers of water outside the coil, has a limited circulation rate and limited heat exchange capacity, especially during periods of pauses in heating (connecting) heating elements, automatically produced by a water thermostat. Therefore, there are coil operation modes in the range of 1500 ... 2500 l / h, when the heating elements are disconnected and the milk temperature at the output of the coil in the booster turns out to be 5 ° ... 7 ° below the hot water temperature due to the "stocking" around the coil turns. This reduces the overall efficiency, leads to the need to increase the setpoint of the water thermostat, and to boil water, especially when high-temperature pasteurization to 92 ° C, recommended, for example, in the production of kefir. To achieve the required pasteurization temperature in the separator, it is necessary to reduce the supply of pasteurized milk by the outlet valve, i.e. limit the performance of the pasteurizer, or increase the water temperature to 100 ° C thermostat setting. Thus, the main disadvantage of the prototype is the limited heat exchange capacity of the screw coil in the water-heating tank, which reduces the pasteurizer productivity and its efficiency. The boiling of water on heating elements during high-temperature pasteurization increases the local overheating of their surface, which reduces the service life and further reduces the efficiency due to evaporation losses originally incorporated, for example, in the design of the analog [3].

Technical result.

The purpose and technical result of the proposed utility model is to increase the productivity of the pasteurizer without changing the length and dimensions of the coil, as well as improving the efficiency and reliability of the heating elements.

The technical essence of the device.

The claimed technical result is achieved by the fact that in a pasteurizer containing a supplementary tank of raw milk with a centrifugal circulation pump and a check valve, a recuperative plate heat exchanger of countercurrent pasteurized and raw milk, a water-heating pasteurization tank with a lid, a screw coil made of a thin-walled tube F40, EHE a water thermostat connected to them, as well as a volume soaker with a thermal sensor, the additional tank being supplied through a centrifugal pump and inlet pipes the heat exchanger tube (raw milk direct flow) is connected by pipelines to the screw coil inlet, and the screw coil outlet is connected to the return valve, the first outlet of which is connected to an additional tank, and the second outlet is connected to the return valve through the volumetric soaker and return pipes of the heat exchanger with the output valve of the pasteurizer, while the temperature sensor is connected to the electrical inlet of the return valve, according to the essence of the utility model, on the water heating cover The calibration tank is equipped with a gear motor with a stirrer placed inside the screw coil and heating elements.

Brief description of the drawings.

Figure 1 shows a schematic diagram of a pasteurizer and an assembly drawing of a water-heating pasteurization tank (TBF).

The pasteurizer contains a supplementary tank of 1 raw milk with sensors of the upper 2 and lower 3 levels, as well as a centrifugal circulation pump 4 and a return valve 5. The flows of raw cold milk and pasteurized hot milk pass counter to the recuperative plate heat exchanger (RPT) 6, so that the outlet nozzle centrifugal pump 4 through the pipe 7 is connected to the inlet pipe 8 RPT 6 raw milk, and the outlet 9 raw milk from RPT 6 - with the input of the screw coil 10 water-heating pasteurization tank (VPB ) 11. Inside the screw coil 10 having a coil diameter D = 530 mm, pitch h = 60 mm, n = 5.5 coils, the total length of the pipe with end fittings L = 10m, are installed heating elements 12, 9 pcs * 5 kW = 45 kw. Screw coil 10 is made of thin-walled stainless steel pipe F40x1 steel AISI316. The outlet 13 of the screw coil 10 through the holder 14 with a quick-release end cap 15 is connected by pipeline to the inlet 16 of the RPT 6 pasteurized milk. The outlet pipe 17 of the RPT 6 is connected to the inlet pipe 18 of the return valve 5, one outlet 19 of which is the output of the PU and the other exit 20 returns the “underheated” milk to the supplementary tank 1. Through the throttle washer 21 dy 5 mm thermal sensor 22 "+ 80 ° With the "14" is connected with the electrical input of the return valve 5.

The soaker 14 is made in the form of a sealed cylindrical tank D = 190 mm, l = 500 mm, volume 14 l, so as to ensure the dwell time of pasteurized milk for at least 13 s at maximum flow rates of 2500 l / h, and it is easy to wash and clean the internal cavity ruffs with the cover removed. RPT 6 is made of forged plates of high-alloyed AISI316 stainless steel with dimensions of 750 × 350 × 0.5, 31 pieces, with an equivalent area of F = 6 sq. M, which provides for a counter flow of 2000 l / h temperature difference not more than T = 10 ° at the exit and the entrance.

A water thermostat 23 connected through a magnetic starter to heating elements 12, stabilizing the desired pasteurization temperature, as well as a float valve 24 supporting the water level below the cutoff of the overflow pipe 25 but above the screw coil 10 is installed in the VPB 11. VPB 11 has a reinforced thermal insulation 26 with a thickness of 40 mm with stainless steel lining. The cover 27 of the TBF 11 is double, insulated with an elastic cuff 28 around the perimeter to reduce heat losses, as well as with four wedge locks 29. The cover 27 is equipped with a worm gear motor 30 with a two-tiered stirrer 31, a wingspan of 350 mm, a capture zone of the blades 400 mm.

In the upper point of the pasteurizer in the spacer 14, an air valve 32 is installed, intended to bleed air during the circulation process. An inch ball valve 33 is installed at the exit of the pasteurizer for convenient control of the capacity in the range of 1000 ... 3000 l / h.

Works pasteurizer as follows. With the help of heating elements 12 and a water thermostat 23 with a magnetic starter, a temperature (85 ° ± 1 °) С is maintained in the water-heating pasteurization tank ВББ 11, which is 4 ° ... 5 ° С higher than the desired minimum pasteurization temperature of 80 ° С, which is installed on the incubator temperature sensor 22 14. In a supplementary tank 1, raw milk + 4 ° С from level 2, 3 sensors is pumped out of the refrigerating tank with an external pump as it is pasteurized.

During the initial filling of empty cavities with milk, the air valve 32 is fully opened, so that the air comes out of RPT 6, coil 10 and stand 14. Milk temperature in stand 14 within 2 ... 3 min reaches 80 ° С, due to accumulated heat VPB 11, and The temperature sensor 22 blocks the flow of the pasteurized milk through the return valve 5 and the throttle washer 21, directing it to the outlet 19. After the air has been released, the air valve 32 is left open to release air during the pasteurization process, since its presence in RPT 6 impairs heat transfer and efficiency. Adjusting the performance of the pasteurizer is carried out by the crane 33. In this case, in the steady state pasteurization mode, the crane 33 provides a nominal flow rate of 2000 l / h.

Raw cold milk + 4 ° С from the filling tank 1 in the steady state is fed through RPT6 to the branch pipe 9, at the same time it is heated to 70 ° C due to the return flow of pasteurized hot milk passing through the pipes 16 and 17. Next in the screw coil 10 there is milk pasteurized, heated to a temperature of 80 ° C with intensive heat exchange with hot water provided by gearmotor 30 with a two-level stirrer 31. It should be noted that intensive rotation of the stirrer 31 and hot water flows in the gaps of 20 mm between turns of wine This coil 10 removes stagnant “stockings” from chilled water layers around coils, increases the heat exchange coefficient of coil 10, reduces thermal pressure between water and milk at outlet 13, increases the effective contact area and power transmitted from heating elements 12 to milk. The flow rate of water from the mixer 31 is an order of magnitude greater than the natural convection from heating elements 12 to the coil 10. Next, the milk in the treater 14 moves for about 15 ... 20 seconds through the inlet pipe 16 RPT 6 of pasteurized milk to the output RPT 6 (pipe 17).

At the same time, it is known from the technical characteristics of the mentioned RPT 6 that in steady state at flow rates Q = 0.57 l / s, 2000 l / h it has a temperature difference of opposite flows T = 10 °, i.e. raw milk is heated from 4 ° to 70 °, and pasteurized milk is cooled from 80 ° to 14 °. Increasing the flow of pasteurized milk using a crane 33 and a half to Q = 3000 l / h increases the temperature difference of opposite flows T to T = 15 °, reducing the recovery rate, and reducing the flow Q to Q = 1000 l / h reduces T to 5 ° C, increasing recovery. It should be noted that stopping the stirrer 31 results in a dynamic “stocking” of chilled water around the coil 10, which worsens the heating of milk in TBF 11, lowers the temperature in the solenoid 14 by 5 ° ... 7 ° to 73 ° ... 75 ° C, and, accordingly , in the socket 9 RPT 6 to 63 ° ... 65 ° C.

To restore the pasteurization temperature during natural convection (without stirrer), the setting of the water thermostat 23 has to be increased to 95 ... 100 ° C, which is accompanied by boiling of water, generation of water vapor and a drop in efficiency, especially in the high-temperature pasteurization mode for milk 92 ° C recommended in the production of kefir .

The average power consumption of heating elements 12 when the pasteurizer costs Q = 2000 l / h, the mass flow rate q = 0.57 kg / s is determined by the ratio

Where c = 3.9 is the heat capacity of milk, T = 10 ° C is the heating of milk in the coil 10 from inlet to outlet. With an increase in costs by 1.5 times to Q = 3000 l / h, q = 0.86 kg / s and, accordingly, T to 15 ° (temperature difference between the output of raw milk from the nozzle 9 RPT 6, as well as the output of the stirrer 14 (input 16 RPT 6) the average power of heating elements according to the relation (1) should increase to 50 kW.

N = 0.86 * 3.9 * 15 = 50 kW

Since in the pasteurizer there are 9 heating elements 12 of 5 kW each, i.e. 45 kW, the water in the TBF 11 will start to cool, the temperature of the separator 14 will fall below 76 ° C and the pasteurization conditions will be violated. Thermal sensor 22 through the return valve 5 will automatically shut off the flow of pasteurized milk from tap 33 and will start returning “submerged” milk to the supplementary tank 1. Therefore, in steady state with selected RPT 6 and coil 10 with stirrer 31 parameters, it is advisable to limit the output of pasteurized milk by tap 33 to 2000 l / h ... 2500 l / h, which can be provided by 9 heating elements 12 with a total capacity of 45 kW. At the same time, further opening of the crane 33 is automatically accompanied by a drop in temperature in the support 14, and the closing - by raising the temperature and stabilizing it at 78 ... 84 ° C.

Thus, the screw coil 10, made of a thin-walled pipe h = 1 mm AISI316, F40 mm, 10 m long, in combination with a gearmotor 30 and a stirrer 31, allows for 2000… 2500 l / h flow to warm up the flow of raw milk from 70 ° C (yield 9 RPT 6) up to 80 ° C with a slight overheating of water (84 ... 85 ° C).

In the prototype [1], without a stirrer, it is necessary to raise the setpoint of the water thermostat 23 and, accordingly, bring the water temperature to 93 ° C to compensate for the cooled water “stocking” around the coil 10. When the pasteurization temperature in the prototype rises to 92 ° C, respectively, water is set by the thermostat 23 at a temperature of 98 ... 100 ° C. This is accompanied by boiling on the surface of heating elements. In addition, it is necessary to significantly reduce the supply of pasteurized milk through the valve 33 to 1000 l / hr, in order to avoid a decrease in the pasteurization temperature, i.e. reduce the productivity of the pasteurizer.

The proposed pasteurizer has an even greater advantage over the analogue [2], where boiling water at an excess pressure of 0.5 atm is incorporated into the design of the water heating tank [3], implemented using a safety valve at 1 atm and an electrical contact pressure gauge that turns off the heating elements when the pressure rises.

Excessive overheating of water up to 110 ° C with an absolute pressure of 1.5 atm makes it possible to obtain a high-temperature pasteurization of 92 ° C at the outlet of a screw coil made of a double closed tube F20x1 15 m long. This creates additional problems in the implementation of an overpressure water tank. In fact, in the analogue [2, 3], 30% of the contact area of the coil is excluded from heat exchange due to closure of the coils, therefore, the coil has to be extended to 15 m. The heat exchange between the coils and the water is blocked by 30%.

Washing and mechanical cleaning of the proposed F40 coil in a pasteurizer using standard foam rubber tampons F60x100, placed at the head of the coil 10 when the pipe 9 is disassembled, presents no problems due to the flow from the centrifugal pump 4, which generates a force from 25 kg to 32 kg at costs up to 8000 l / h, 2 l / s, i.e. 5 seconds after switching on the pump 4, the foam wad “flies out” at the end of the coil 10.

Cleaning screw tubes F20x1 with a length of 15 m analogue [2, 3] is a big problem. The reliability of the heating elements in the proposed pasteurizer also increases, due to the reduction of local overheating on their surface, due to the flow of water from the mixer, eliminating vaporization.

Compared with capacitive analogues [6, 7], the proposed pasteurizer provides savings from 80% to 93% of electricity due to heat-cold recovery in RPT 6.

Thus, the installation of the gear motor on the cover of the water-heating pasteurization tank with a stirrer placed inside the screw coil and heating elements, improves the pasteurizer performance, especially during high-temperature pasteurization, increasing its efficiency, eliminates boiling on the heating surface, which increases their service life and reliability.

Information sources

1. Pasteurization unit Patent RU №120541 from 10.05.2012

2. Device for pasteurization. Patent RU 2007146478.

3. A set of equipment for pasteurization IPKS-013R-2500R. www.elf4m.ru/passport_ipks-013-01.pdf

4. Installation for pasteurization and cooling of liquid food PMR-02-W with an electric boiler up to 2000 l / h. www.pasterizator.ru

5. Installation for pasteurization and cooling of liquid food products (pasteurizer) PMR-02-VT with rotary heaters up to 1600 l / h. www.pasterizator.ru

6. Baths long pasteurization. Patent RU No. 2007139028.

7. Milk pasteurization refrigeration unit. Patent RU No. 2436293 of 05/17/2010.

Claims (1)

A pasteurizer containing a supplementary tank of raw milk with a centrifugal circulation pump and a return valve, a recuperative plate heat exchanger of countercurrent pasteurized and raw milk, a water-heating pasteurization tank with a lid, a screw coil made of a thin-walled pipe, tubular heaters and an associated steam oven, with a steam oven, a steam oven, and a steam oven, connected with a steam oven, a steam oven, a screw coil made of a thin-walled pipe, tubular heaters and an associated thermostat with a steam oven and a steam oven. an incubator with a thermal sensor, the additional tank being connected through a centrifugal pump and the inlets of the heat exchanger (forward flow of raw milk) pipelines with a screw coil inlet, and a screw coil outlet through a volumetric soaker and return pipes of the heat exchanger (countercurrent of pasteurized milk) are connected by pipelines to the return valve inlet, the first outlet of which is connected to the secondary tank, and the second outlet is connected to the outlet cock of the pasteurizer, while the thermal sensor is connected with electric return valve inlet, characterized in that a gear motor with an agitator placed inside the water heating pasteurization tank is installed on the cover three helical coils and heaters.

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