Method of heat-moisture treatment of building materials with heat recovery and installation for its implementation

 

(57) Abstract:

Method of heat-moisture treatment of building materials with heat recovery, accumulated products in the autoclave the source, is that the supply of steam from the autoclave source is carried out at a constant absolute pressure in the autoclave is the receiver within 0,107-0,115 MPa to achieve in it the temperature of 85-95oAnd further steam exercise force at a constant volume system source-receiver. The resulting condensate to a temperature below the temperature in the autoclave the source at the end of the recovery remove open receiver, and the condensate with a higher temperature accumulate in the collector under pressure for subsequent utilization of the pair of secondary boil. In addition, the way to achieve the pressure differential between the source and receiver is approximately 0.08 to 0.1 MPa steam in the autoclave receiver is carried out under natural pressure drop and the further supply of steam is carried out forcibly with the help of the compressor. Installation for implementing the method contains a collection of condensate under pressure, a compressor for forcing steam from the autoclave-source the processing of construction materials. 2 S. and 4 C.p. f-crystals, 1 Il.

The invention relates to a method of heat-moisture treatment of construction and other materials and facilities for its implementation.

There is a method of heat-moisture treatment of building materials in the autoclave by heating loaded products with saturated steam supplied directly from the primary steam generator, with the rise of temperature up 101-103oC at a constant absolute pressure 0,107-0,115 MPa and with a further rise of temperature and pressure in the autoclave after reaching the Central zone of the products temperature 65-70oC [1].

This method, however, has the disadvantage that it does not provide for the recovery of heat accumulated products in the process of heat-moisture treatment.

Known another method of heat-moisture treatment of building materials in the autoclave crude product (autoclave-receiver), by his message autoclave, which ended in a heat-moisture treatment (autoclave-source) heat recovery steam released from products in the autoclave the source when you reset it pressure [2].

This method, however, has the is 0.25 to 0.35 MPa, that allows to reduce the absolute pressure in the autoclave the source below 0,35-0,45 MPa.

Method of heat-moisture treatment of building materials according to the invention differs from the known fact that the steam in the autoclave receiver from autoclave-source carried out while maintaining the autoclave-receiver constant absolute pressure within 0,107-0,115 MPa to achieve in it the temperature of 85-95oC, and further the secondary steam flow in the latter is carried out at constant volume system source-receiver. When this driving force is first the natural pressure difference between the source and the receiver, and then force differential created by the compressor. The transition to the forced movement of a pair of preferably carried out after reducing the pressure differential between the source and receiver to 0.08-0.1 MPa.

To reduce heat and improve the efficiency of the recovery method according to the invention formed in the autoclave-receiver condensate with a temperature below the temperature in the autoclave the source at the end of the recovery remove open receiver, and the rest of the condensate with a higher temperature, accumulate in the collection of kuusysi steam fed into the autoclave receiver also first under natural pressure drop simultaneously or sequentially with the steam from the autoclave-source and then forced to use a compressor.

The final recovery parameter (pressure and temperature) in both sources (the autoclave and the condensate collector) determine, based on economic considerations and comparisons of energy, optionally returned to the system through recovery and spent the forced movement of the pair.

The method according to the invention also permits the inclusion in the recovery system of the heat accumulator, which greatly expands the possibilities of maneuvering in a small number of autoclaves (up to one) or a significant difference in the time of the end of the process in the autoclave the source and the beginning of the process in the autoclave is the receiver. In order to increase the efficiency of recovery also resort to forced displacement pair between the source, the battery and the receiver.

Features of the method according to the invention, and installation for its implementation clearly illustrated by the following example and the accompanying drawing, which shows a diagram of the installation consisting of one or more autoclaves (1), one or more collections of condensate (2), compressor (3), a heat accumulator (4), recuperation line (5) to bypass steam, line (7) to remove the air-steam mixture from the autoclave receiver or reset of vacuum autoclave-source and collection of condensate line (8) to remove condensate in the collection of the condenser pressure line (9) to remove condensate in an open receiver, line (10) for the supply of steam from the primary steam generator, and the corresponding shut-off and control valves, enumerated below when describing the operation of the plant.

Of course, not all of the above elements of the unit are required. You can, for example, to abandon the condensate collector (2) or compressor (3), however, this will reduce the effectiveness of recovery. You can also abandon heat accumulator (4), but with a smaller number of autoclaves this will limit your ability to maneuver.

The installation according to the invention operates as follows.

At the end of moist curing in the autoclave the source (s) And download the raw products in the autoclave receiver (P) last connected through valves(11), (12), (13) and recovery line (5) with autoclave-source (s) And the condensate collector (2) through the valve (16) from line (9) condensate discharge into the open receiver (not shown in the diagram) and the and condensate collector (2) under natural pressure drop begins to flow into the autoclave receiver (P), where it condenses on the cold products, they heat up. As a consequence, the pressure in the autoclave the source (s) And in the condensate collector (2) starts to decrease and the moisture contained in the products, the condensate at the bottom of the autoclave and in the collection become overheated and boiled, and released when it goes to steam autoclave receiver (P). When the temperature of the condensate flowing from the autoclave receiver becomes higher than the lowest temperature of the secondary vapor at the end of the recovery (80-100oC) close the valve (16) to the line (9) removal of condensate into the open receiver and open the valve (14) to the line (8) for feeding the condensate in the condensate collector under pressure. The above process steam in the autoclave receiver (P) continues up until the natural pressure difference between the source and receiver will not decrease so that the rate of admission of steam into the autoclave receiver may be significantly slower. This usually occurs when the differential pressure between the source and the receiver of the order of 0.08 to 0.1 MPa.

To proceed with the required speed close valve (11) and open valve (17) and (18) for the supply of steam from the autoclave the source (s) And condensate collector (2) in the autoclave reception is based processing in the autoclave source autoclave receiver is not ready to start, and to delay the unloading of the first undesirable obtained from sources (I) and (2) the secondary steam is directed under natural pressure drop through the valve (19) or forced through the compressor (3) and valve (20) in the heat accumulator (4); upon the occurrence of suitable conditions is inclined in the battery heat is used, as described above.

Upon exhaustion of the possibilities of recovery in the optimal mode further rise of temperature and pressure in the autoclave-the receiver is carried out by feeding him a pair from the primary steam generator through line 10 and valve 21. At the same time the autoclave-source (s) and the condensate collector (2) disconnect from the recovery line (5) or (6), connected to the atmosphere through the valves (13) and (15) for collecting vacuum, and the condensate from the collector (2) through the valve (22) and line (8) remove the open receiver.

Example 1.

In an autoclave with a diameter of 2 m and a length of 19 m produce heat and humidity processing solid sand-lime brick saturated steam at a pressure of 0.9 MPa and a temperature of the environment and products 175oC. In the autoclave load 15400 bricks with an initial temperature of 45oC and humidity of 6.5. The total mass of the products is 55 500 kg of Water equivalent load of raw products in the autoclave receiver in the last heat and humidity begin processing by feeding it a couple of autoclave. In accordance with the known method of the bypass with the simultaneous rise of the pressure in the autoclave-receiver recovery continue to reduce the absolute pressure in the autoclave the source to 0.4 MPa and the rise of absolute pressure in the autoclave is the receiver to 0.3 MPa. The specified pressure corresponds to the temperature in the autoclave source 145oC.

According to calculations by reducing the temperature of products in the past to the specified value cannot recover:

without the use of secondary heat boiling condensate: 1,94 GJ/cycle or about 16% of the total heat consumed for heat and humidity treatment;

- recovered amount of heat can heat the product on the 24oC;

- heat supplied from the secondary boiling condensate will be 0.2 GJ/cycle or about 1.7%,

so to complicate the system and process additional collections condensate is impractical.

Example 2.

When the autoclave described in example 1 to produce a recovery method according to the invention with a lower absolute pressure in the autoclave is the source to 0.047 MPa and temperature of products in it and in the collection of condensate up to 80oC. Formed in the autoclave-receiver condensive in the collection of condensate, working under pressure.

The autoclave receiver (P) after downloading it raw and closing lids connect with autoclave-source (s) And the condensate collector (3) through the bypass line (5) and with the atmosphere through line (7). In this case, steam from the autoclave and the condensate collector under the natural action of the differential pressure supplied to the autoclave receiver, where it condenses on the cold products, they heat up. In the initial period of the steam in the autoclave-source is carried out at a constant absolute pressure in it 0,107-0,115 MPa to achieve a temperature of 85-95oC. Then, the autoclave receiver is cut off from the atmosphere, continuing to serve him in pairs of sources until the differential pressure between sources and receivers will not be reduced to approximately 0.08 to 0.1 MPa and the rate of steam in the receiver may be significantly slower.

To continue recovery autoclave the source and the condensate collector is connected to the bypass line (6) from which the secondary pairs are served in the bypass line (5) compressor (3) and continue recovery until reaching the source temperature 80oC and absolute pressure 0.047 MPa.

According to estimates under the above procedure Pease autoclave with the decrease in temperature in the interval:

175-145oC is 1,94 GJ/loop

145-120oC is 1,52 GJ/loop

120-100oC is 1.16 GJ/loop

100-80oC is 1.11 GJ/loop

The amount of heat given secondary steam boiling condensate with an initial temperature of 126oC when the decrease in temperature in the interval:

126-100oC is 0,38 GJ/loop

100-80oC is 0,28 GJ/loop

Thus, the total number recuperated heat by the method according to the invention is:

of 6.4 GJ/cycle, including

compared with the known method

4,45 GJ/cycle, including

due to the force of the steam supply

2,93 GJ/cycle, including

due to the boiling of the condensate

0,66 GJ/loop

The corresponding energy consumption for forced supply of steam is 0.1 GJ/cycle.

Sources of information:

1. Khavkin L. M. Technology of silicate bricks.- M.: stroiizdat, 1982, S. 277.

2. SU 309597 A, 06.09.72.

1. Method of heat-moisture treatment of building materials with heat recovery, accumulated products in the autoclave the source by loading items into the autoclave receiver, his message with autoclave-source and agravante receiver from the source is carried out at a constant absolute pressure in the autoclave-receiver 0,107 - 1,115 MPa to achieve in a temperature environment of 85 - 95oC, and further the flow of secondary vapor exercise force at a constant volume system source-receiver.

2. The method according to p. 1, characterized in that the condensate from the autoclave receiver with a temperature below the minimum achievable temperature sources secondary steam at the end of the recovery remove open receiver, and the condensate with a higher temperature store in a sealed collection under pressure.

3. The method according to p. 1 or 2, characterized in that to reduce the natural pressure differential between the source and receiver to 0.08 - 0.1 MPa recovery carried out under natural pressure drop, and the further supply of secondary steam from a source in the form of an autoclave and collection of condensate in the autoclave receiver perform a forced manner to reduce the temperature in the sources to an economical value that is determined from a comparison of the amount of recuperated energy spent on ensuring that the forced movement of steam.

4. The method according to any of paragraphs.1 to 3, characterized in that after heat-moisture treatment product steam from the autoclave and collecting the necessity of forced displacement pair.

5. Installation for implementing the method according to any one of paragraphs. 1 to 3, consisting of autoclaves with relevant communications and valve, characterized in that it contains a collection of condensate under pressure and a device for forced delivery of secondary steam from the autoclave and the collection of condensate in the autoclave receiver.

6. Installation under item 5, characterized in that it contains a heat accumulator, installed between the source and receiver.

 

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